Electronic devices having ambient light sensors with lens diffusers
An electronic device may be provided with a display mounted in a housing. The display may have an array of pixels configured to display images. A display cover layer may overlap the array of pixels. A light sensor such as a color ambient light sensor may be mounted in the electronic device and may receive ambient light through an ambient light sensor window region in the display cover layer or other portion of the electronic device. A diffuser may be located between the display cover layer and the ambient light sensor. The diffuser may have a substrate such as a glass substrate. A lens layer may be supported by the substrate. The lens layer may be formed from a layer of ultraviolet-light-curable polymer in which an array of lenses has been formed. An infrared-light-blocking-and-visible-light-transmitting filter may be used to reduce infrared light reaching the ambient light sensor.
1. An electronic device, comprising:
a display having pixels that displays images;
a display cover layer that overlaps the pixels;
a light diffuser having a substrate layer and a lens layer on the substrate layer, wherein the light diffuser is coupled to the display cover layer;
a coating layer on a curved surface of the lens layer;
an ambient light sensor configured to measure ambient light passing through the light diffuser; and
control circuitry configured to adjust the display using the measured ambient light.
2. The electronic device defined in claim 1 , wherein the ambient light sensor is configured to measure the ambient light through the display cover layer.
3. The electronic device defined in claim 2 wherein the lens layer has concave lenses.
4. The electronic device defined in claim 3 wherein the diffuser has a first side facing the display cover layer and a second side facing away from the display cover layer and wherein the concave lenses are formed on the first side.
5. The electronic device defined in claim 3 wherein the diffuser has a first side facing the display cover layer and a second side facing away from the display cover layer and wherein the concave lenses are formed on the second side.
6. The electronic device defined in claim 2 wherein the lens layer has convex lenses.
7. The electronic device defined in claim 6 wherein the diffuser has a first side facing the display cover layer and a second side facing away from the display cover layer and wherein the convex lenses are formed on the first side.
8. The electronic device defined in claim 6 wherein the diffuser has a first side facing the display cover layer and a second side facing away from the display cover layer and wherein the convex lenses are formed on the second side.
9. The electronic device defined in claim 1 wherein the lens layer comprises ultraviolet-curable polymer.
10. The electronic device defined in claim 1 wherein the diffuser comprises a polymer buffer layer between the lens layer and the substrate layer.
11. The electronic device defined in claim 10 further comprising light-scattering particles embedded in the polymer buffer layer.
12. The electronic device defined in claim 1 wherein the substrate layer comprises an infrared-light-blocking-and-visible-light transmitting layer.
13. The electronic device defined in claim 1 wherein the substrate layer comprises blue glass.
14. An electronic device, comprising:
an ambient light sensor diffuser, comprising:
a substrate layer;
a buffer layer on the substrate layer; and
a polymer lens layer on the buffer layer, wherein the buffer layer prevents delamination of the polymer lens layer from the substrate layer and wherein the buffer layer is interposed between the substrate layer and the polymer lens layer; and
an ambient light sensor that receives light that has passed through the ambient light sensor diffuser.
15. The electronic device defined in claim 14 wherein the polymer lens layer has an array of lenses and wherein each lens has a diameter of 2-25 microns, the electronic device further comprising:
a display having pixels that displays images; and
control circuitry configured to adjust the display based on a measurement from the ambient light sensor.
16. The electronic device defined in claim 15 wherein the lenses are concave lenses.
17. The electronic device defined in claim 15 wherein the lenses are convex lenses.
18. The electronic device defined in claim 15 wherein the lenses are arranged in an irregular pattern, wherein the buffer layer is formed from a first polymer, and wherein the polymer lens layer is formed from a second polymer that is different than the first polymer.
19. An electronic device, comprising:
a display;
a diffuser having a substrate and a continuous cured polymer layer with lenses; and
an ambient light sensor configured to measure ambient light that has been passed through the diffuser; and
control circuitry configured to adjust the display using the measured ambient light.
20. The electronic device defined in claim 19 further comprising a polymer buffer layer interposed between the cured polymer layer and the substrate, wherein the substrate comprises a glass layer, wherein the cured polymer layer comprises a first polymer, and wherein the polymer buffer layer comprises a second polymer that is different than the first polymer.