Abstract: A device may include an electronic display to display an image frame based on image data. The electronic display may include an illuminator that generates light, multiple light regulators that control emission of the light pixel locations on the electronic display based on bitplane data, and driving circuitry that applies an operating electrical stimulus to the illuminator during an emission period of the image frame and a reference electrical stimulus to the illuminator during an off period of the image frame. While the reference electrical stimulus is applied the bitplane data may be indicative of off bitplane. Additionally, the electronic display may include measurement circuitry that measures a response characteristic of the illuminator in response to the reference electrical stimulus and generates temperature data indicative of the temperature of the illuminator based on the response characteristic.

Abstract: An electronic device such as a wearable electronic device may have a band. The band may form a stand-alone device or a strap for a wristwatch unit or other device. Electrical components may be mounted on flexible printed circuit substrates. A substrate may be encapsulated by elastomeric polymer material or other material forming the band. The elastomeric polymer material may form cavities that receive the electrical components. Components such as light-emitting diodes may be mounted to the flexible printed circuit substrates so that the light-emitting diodes are located in the cavities. Reflective sidewalls in the cavities may reflect light from the light-emitting diodes outwardly through a thinned portion of the band. Light-diffusing material in the cavities may be formed from clear polymer with light-scattering particles.

Abstract: An electronic device may have a display and a gaze tracking system. The electronic device may display images on the display that have a higher resolution in a portion of the display that overlaps a gaze location than other portions of the display. Timing controller circuitry and column driver circuitry may include interpolation and filter circuitry. The interpolation and filter circuitry may be used to perform nearest neighbor interpolation and two-dimensional spatial filtering on low resolution image data. Display driver circuitry may be configured to load higher resolution data into selected portions of a display. The display driver circuitry may include low and high resolution image data buffers and configurable row driver circuitry. Block enable transistors may be included in a display to allow selected blocks of pixels to be loaded with high resolution image data.

Abstract: A rigid flex printed circuit board (PCB), method of manufacture, and display system incorporating the same are described. In an embodiment, a rigid flex PCB includes a flexible area extending from an adjacent routing area that is thicker than the flexible area. A flexible inner core spans the flexible area and the adjacent routing area. Outer stack-up layers are on the flexible inner core in the adjacent routing area. A cavity is formed in the outer stack-up layers in the routing area and exposes the flexible inner core. In an embodiment, a display system including such a circuit board may include an electronic component mounted on the flexible inner core within the cavity, and a distal end of the flexible area is bonded to a display panel.

Abstract: A rigid flex printed circuit board (PCB), method of manufacture, and display system incorporating the same are described. In an embodiment, a rigid flex PCB includes a flexible area extending from an adjacent routing area that is thicker than the flexible area. A flexible inner core spans the flexible area and the adjacent routing area. Outer stack-up layers are on the flexible inner core in the adjacent routing area. A cavity is formed in the outer stack-up layers in the routing area and exposes the flexible inner core. In an embodiment, a display system including such a circuit board may include an electronic component mounted on the flexible inner core within the cavity, and a distal end of the flexible area is bonded to a display panel.

Abstract: A display device may include rows of pixels that displays image data on a display, data lines coupled to the rows of pixels, and a digital-to-analog converter (DAC) that outputs a ramp voltage signal including a data voltage to be depicted on a first pixel of the rows of pixels. The display device may also include a capacitor that receives the ramp voltage signal via the DAC and a circuit that sends a control signal to a circuit component that causes the DAC to couple to the capacitor via one of the data lines for a duration of time that comprises a first time when the ramp voltage signal is below the data voltage and a second time when the ramp voltage signal is approximately equal to the data voltage. The capacitor is coupled to the DAC when the ramp voltage signal is greater than zero.

Abstract: An electronic device such as a wearable electronic device may have a band. The band may form a stand-alone device or a strap for a wristwatch unit or other device. Electrical components may be mounted on flexible printed circuit substrates. A substrate may be encapsulated by elastomeric polymer material or other material forming the band. The elastomeric polymer material may form cavities that receive the electrical components. Components such as light-emitting diodes may be mounted to the flexible printed circuit substrates so that the light-emitting diodes are located in the cavities. Reflective sidewalls in the cavities may reflect light from the light-emitting diodes outwardly through a thinned portion of the band. Light-diffusing material in the cavities may be formed from clear polymer with light-scattering particles.

Abstract: An electronic device includes a display having a reference array that includes a first pixel. The display also includes a first emission power supply coupled to the first pixel. The display further includes an active array having a second pixel. The display also includes a second emission power supply coupled to the second pixel.

Abstract: An electronic device may have a display and a gaze tracking system. The electronic device may display images on the display that have a higher resolution in a portion of the display that overlaps a gaze location than other portions of the display. Timing controller circuitry and column driver circuitry may include interpolation and filter circuitry. The interpolation and filter circuitry may be used to perform nearest neighbor interpolation and two-dimensional spatial filtering on low resolution image data. Display driver circuitry may be configured to load higher resolution data into selected portions of a display. The display driver circuitry may include low and high resolution image data buffers and configurable row driver circuitry. Block enable transistors may be included in a display to allow selected blocks of pixels to be loaded with high resolution image data.

Abstract: An electronic device includes a display having a reference array that includes a first pixel. The display also includes a first emission power supply coupled to the first pixel. The display further includes an active array having a second pixel. The display also includes a second emission power supply coupled to the second pixel.

Abstract: A display device may include rows of pixels that displays image data on a display, data lines coupled to the rows of pixels, and a digital-to-analog converter (DAC) that outputs a ramp voltage signal including a data voltage to be depicted on a first pixel of the rows of pixels. The display device may also include a capacitor that receives the ramp voltage signal via the DAC and a circuit that sends a control signal to a circuit component that causes the DAC to couple to the capacitor via one of the data lines for a duration of time that comprises a first time when the ramp voltage signal is below the data voltage and a second time when the ramp voltage signal is approximately equal to the data voltage. The capacitor is coupled to the DAC when the ramp voltage signal is greater than zero.

Abstract: An electronic device may have a display that has column driver circuitry for providing data line signals to data lines in an array of display pixels. Gate line signals on gate lines in the array and the data line signals may be used in controlling the array to display images for a user of the electronic device. The column driver circuitry may include voltage divider circuitry such as a chain of resistors with reference voltage nodes. The nodes may be provided with reference voltages from corresponding input pins. During normal operation of the column driver circuitry, a voltage supply may supply a set of column driver voltage divider reference voltages to the input pins. During power state transitions when power supply lines for the column driver circuitry might be subjected to undesirable current surges, the voltage supply may be used in supplying transitional voltages to the input pins.

Abstract: An electronic device may have a display that has column driver circuitry for providing data line signals to data lines in an array of display pixels. Gate line signals on gate lines in the array and the data line signals may be used in controlling the array to display images for a user of the electronic device. The column driver circuitry may include voltage divider circuitry such as a chain of resistors with reference voltage nodes. The nodes may be provided with reference voltages from corresponding input pins. During normal operation of the column driver circuitry, a voltage supply may supply a set of column driver voltage divider reference voltages to the input pins. During power state transitions when power supply lines for the column driver circuitry might be subjected to undesirable current surges, the voltage supply may be used in supplying transitional voltages to the input pins.