Abstract: An electronic device may be provided with a touch screen display that is controlled based on information from a proximity sensor. The proximity sensor may have a light source that emits infrared light and a light detector that detects reflected infrared light. When the electronic device is in the vicinity of a user's head, the proximity sensor may produce data indicative of the presence of the user's head. Variations in proximity sensor output due to user hair color and smudges on the proximity sensor can be accommodated by using an electrical sensing mechanism in addition to the light sensing mechanism. The proximity sensor may include a pair of capacitive electrodes for generating an electric field in the vicinity of the device. The presence of a user's head can sufficiently disturb the electric field so as to produce data indicative of the presence of the user's head.

Abstract: An electronic device may be provided with a touch screen display that is controlled based on information from a proximity sensor. The proximity sensor may have a light source that emits infrared light and a light detector that detects reflected infrared light. When the electronic device is in the vicinity of a user's head, the proximity sensor may produce data indicative of the presence of the user's head. Variations in proximity sensor output due to user hair color and smudges on the proximity sensor can be accommodated by using an electrical sensing mechanism in addition to the light sensing mechanism. The proximity sensor may include a pair of capacitive electrodes for generating an electric field in the vicinity of the device. The presence of a user's head can sufficiently disturb the electric field so as to produce data indicative of the presence of the user's head.

Abstract: An electronic device may be provided with a touch screen display that is controlled based on information from a proximity sensor attached underneath a display layer. The proximity sensor may have a light source that emits infrared light and a light detector that detects reflected infrared light. When the electronic device is in the vicinity of a user's head, the proximity sensor may produce data indicative of the presence of the user's head. Variations in proximity sensor output due to smudges on the proximity sensor can be detected by providing the proximity sensor with an additional light source. The additional light source may be used to inject light into the display layer. The injected light may be guided within the display layer by total internal reflection. In the presence of smudge, the internally reflecting light may deviate from its normal propagation path.

Abstract: An electronic device may be provided with a touch screen display that is controlled based on information from a proximity sensor. The proximity sensor may have a light source that emits infrared light and a light detector that detects reflected infrared light. When the electronic device is in the vicinity of a user's head, the proximity sensor may produce data indicative of the presence of the user's head. Variations in proximity sensor output due to user hair color and smudges on the proximity sensor can be accommodated by using an electrical sensing mechanism in addition to the light sensing mechanism. The proximity sensor may include a pair of capacitive electrodes for generating an electric field in the vicinity of the device. The presence of a user's head can sufficiently disturb the electric field so as to produce data indicative of the presence of the user's head.

Abstract: An electronic device may be provided that has a display. The display may produce light using a backlight unit or using an array of light-emitting display pixels. An ambient light sensor may be mounted under an active area of the display to measure ambient light that is transmitted through the display. The display may be periodically disabled to prevent the display from producing light that interferes with the ambient light sensor. Display pixels may be coupled to a common cathode switch that can be periodically opened or the backlight in a display with a backlight can be periodically turned off. Control circuitry for periodically disabling the display while enabling the ambient light sensor may be implemented using a display driver integrated circuit mounted to a display.

Abstract: An electronic device may be provided with a touch screen display that is controlled based on information from a proximity sensor. The proximity sensor may have a light source that emits infrared light and a light detector that detects reflected infrared light. When the electronic device is in the vicinity of a user's head, the proximity sensor may produce data indicative of the presence of the user's head. Variations in proximity sensor output due to user hair color and smudges on the proximity sensor can be accommodated by using an electrical sensing mechanism in addition to the light sensing mechanism. The proximity sensor may include a pair of capacitive electrodes for generating an electric field in the vicinity of the device. The presence of a user's head can sufficiently disturb the electric field so as to produce data indicative of the presence of the user's head.

Abstract: An electronic device may be provided with a touch screen display that is controlled based on information from a proximity sensor attached underneath a display layer. The proximity sensor may have a light source that emits infrared light and a light detector that detects reflected infrared light. When the electronic device is in the vicinity of a user's head, the proximity sensor may produce data indicative of the presence of the user's head. Variations in proximity sensor output due to smudges on the proximity sensor can be detected by providing the proximity sensor with an additional light source. The additional light source may be used to inject light into the display layer. The injected light may be guided within the display layer by total internal reflection. In the presence of smudge, the internally reflecting light may deviate from its normal propagation path.

Abstract: An electronic device may be provided that has a display. The display may produce light using a backlight unit or using an array of light-emitting display pixels. An ambient light sensor may be mounted under an active area of the display to measure ambient light that is transmitted through the display. The display may be periodically disabled to prevent the display from producing light that interferes with the ambient light sensor. Display pixels may be coupled to a common cathode switch that can be periodically opened or the backlight in a display with a backlight can be periodically turned off. Control circuitry for periodically disabling the display while enabling the ambient light sensor may be implemented using a display driver integrated circuit mounted to a display.