Abstract: A device includes a plurality of first LEDs, a plurality of second LEDs, at least one controllable current source that is configured to generate at least one bias current for driving the plurality of first LEDs and the plurality of second LEDs, and a plurality of measurement circuits, each of which is configured to measure a current-voltage (I-V) performance characteristic of at least one of the plurality of first LEDs. A property of a first bias current of the at least one bias current is determined as a function of at least two measurements of the I-V performance characteristic of the at least one of the plurality of first LEDs, and the at least two measurements of the I-V performance characteristic are acquired while the first bias current is applied to the at least one of the plurality of first LEDs and the plurality of second LEDs.

Abstract: In an embodiment, a headset display device includes a central processor and multiple projector integrated circuits each coupled to the central processor and configured to process image data. Each projector integrated circuit includes multiple first integrated circuits, each including a light emitter array. Each projector integrated circuit includes a second integrated circuit coupled to the multiple first integrated circuits. The second integrated circuit includes a graphics processor configured to generate transformed image data correcting for geometrical or brightness distortions and (2) is configured to provide the transformed image data to the multiple first integrated circuits for display.

Abstract: Techniques are described for operating a display system comprising a light source, a scanning assembly, and a controller. The light source includes a plurality of emitters arranged in a column. The scanning assembly includes a reflective surface. A control signal including linear or sinusoidal pulses is applied to cause the reflective surface to rotate. The controller drives the emitters in sequence, using a same image data value, and in synchronization with the rotating of the reflective surface such that light emitted by different emitters of the plurality of emitters is reflected onto a same pixel of an output image. Changes in rotational speed are compensated for through increasing an emission duration for a first row driven while the reflective surface is rotating at a slower rotational speed, relative to an emission duration for a second row driven while the reflective surface is rotating at a faster rotational speed.

Abstract: A display operates a plurality of light emitters using pulse width modulations (PWM). Pixel data for a pixel location may be separated into a first subset of bits and a second subset of bits. The display device turns on first light emitters for first PWM turn-on times in accordance with the first subset of bits within a PWM cycle. The display device turns on second light emitters for PWM on time second PWM turn-on times in accordance with the second subset of bits within the PWM cycle. The current level that drives the first emitters may remain constant during the first turn-on times but may be higher than the current level that drives the second emitters. The first emitters may generate light in accordance with the most significant bits of pixel data while the second emitters may generate light in accordance with the least significant bits of the pixel data.

Abstract: In an embodiment, a method includes accessing a first rendered frame generated at a first frame rate. The method includes generating, based on the first rendered frame, one or more sub-frames at a second frame rate that is higher than the first frame rate. A first sub-frame of the one or more sub-frames is generated by determining a displacement measure associated with an anticipated movement of an optics component of a display system and applying, based on the displacement measure, one or more transformations to the first rendered frame to generate the first sub-frame. The first sub-frame is to be perceived by a user using the optics component of the display system. The method includes outputting the one or more sub-frames for display at the second frame rate. The one or more sub-frames are perceived by the user using the optics component of the display system.

Abstract: Techniques are described for operating a display system comprising a light source and a scanning assembly. The light source includes a plurality of emitters arranged in a column and circuitry configured to drive the emitters based on image data. The scanning assembly includes a reflective surface facing the light source, the reflective surface being rotatable in at least one dimension. A control signal including periodic, non-linear pulses causes the reflective surface to rotate through a range of scan angles, thereby forming an output image based on reflection of emitted light. The image data is supplied to the light source in synchronization with the rotational movement of the reflective surface. Changes in rotation speed due to the non-linear nature of the control signal are compensated for by adjusting emission durations for different rows to provide different emission durations at different times based on changes in the linearity of the control signal.

Abstract: Systems and methods for controlling a display apparatus are provided. In one example, an apparatus comprises a display comprising a plurality of light emitting diodes (LED), a display control circuit configured to generate display control signals, and a test module configured to generate test control signals. In a test operation mode, at least one LED of the plurality of LEDs is configured to be controlled by the test control signals from the test module to conduct at least one test output current. The test module can determine electrical characteristics of the at least one LED based on the at least one test output current. The display control circuit can adjust the display control signals based on the electrical characteristics of the at least one LED.

Abstract: A scanning type display device includes a light source that includes multiple rows and columns of light emitters. The display device also includes a rotatable mirror that projects light to different areas of an image field as the mirror rotates. There can be a redundant number to light emitters in the light source to increase the brightness of the pixels in the image field. A data driver may replicate and shift data values among light emitters of the same columns. The light emitters may operate in conjunction with the mirror in a synchronized manner. Owing to the shift in data value and the rotation of the mirror, the mirror may first project light from a first light emitter to a pixel and may then project light from a second light emitter with the same brightness level to the same pixel. The shifting may continue for additional light emitters.

Abstract: Techniques are described for operating a display comprising an array of emitters arranged in at least one column. Data is shifted through the emitters of the column using a data shifting circuit. The data can be shifted sequentially, one emitter at a time. The data shifting circuit includes storage elements for temporary storage of the data as it is shifted down the column. The data can be stored as a charge on a capacitor, where the capacitor is charged to a particular voltage according to a current from a current mirror. The shifting can be performed in synchronization with scanning of the emitters by a scanning assembly, where the scanning produces an output image for viewing by a user.

Abstract: Techniques are described for collecting feedback on a display comprising a plurality of emitters arranged in a column. Each emitter is driven by a respective emitter cell that generates a driving current for the emitter based on digital data or an analog representation thereof. The digital data or analog representation is sequentially shifted through the entire column. An electrical signal associated with a last emitter to be driven based on the digital data or analog representation is measured, along a feedback path formed by selectively opening or closing a first switch and a second switch, which are respectively connectable to an anode and a cathode of the last emitter. Since each emitter cell contributes to the electrical signal, the value of the electrical signal is indicative of whether there is a problem with an emitter cell somewhere in the column. The subsequently driving of the emitters is adjusted accordingly.

Abstract: Embodiments relate to driving first light emitting diodes (LEDs) of a first color to emit light during first subframes of emission frames, driving second LEDs of a second color to emit light during second subframes of emission frames, and driving third LEDs of a third color to emit light during the second subframes of emission frames. Light emitted from the first, second, and third LEDs is directed onto a mirror that reflects the light onto a plurality of pixel locations of an image field. The first, second, and third LEDs are aligned on an array of LEDs such that the first LEDs are at a first distance away from the second LEDs, and the first LEDs are at a second distance away from the third LEDs.

Abstract: Disclosed herein are display systems and techniques for operating a display in a display system. An output image is formed by scanning a column of light emitters such that emitters in different rows of the column contribute to a same location in the output image. The emitters are driven using pulse-width modulation (PWM). PWM pulses are applied in synchronization with the scanning to cause emitters to emit light at an intensity corresponding to an illumination parameter. The driving includes generating, based on an illumination parameter, a PWM pulse by applying an analog signal in combination with applying a digital signal. The analog signal controls an amplitude of the PWM pulse. The digital signal controls a duration of the PWM pulse.

Abstract: Techniques are described for operating a display comprising an array of emitters arranged in at least one column. A data shifting circuit stores digital data or an analog representation thereof in a first storage element. The data shifting circuit outputs the digital data or analog representation multiple times to a display driver circuit, using a multiplexer. The first storage element can be a shift register or a capacitor. Digital data can be internally shifted within the data shifting circuit, through multiple shift registers, prior to output to the display driver circuit. An analog representation can be stored and read from the same capacitor without internal shifting. The display driver circuit drives a different emitter of the column each time. A scanning assembly including a reflective surface that receives light from the emitter array forms an output image by rotating the reflective surface in synchronization with driving of the emitters.

Abstract: Embodiments relate to driving first light emitting diodes (LEDs) of a first color to emit light during first subframes of emission frames, driving second LEDs of a second color to emit light during second subframes of emission frames, and driving third LEDs of a third color to emit light during the second subframes of emission frames. Light emitted from the first, second, and third LEDs is directed onto a mirror that reflects the light onto a plurality of pixel locations of an image field. The first, second, and third LEDs are aligned on an array of LEDs such that the first LEDs are at a first distance away from the second LEDs, and the first LEDs are at a second distance away from the third LEDs.

Abstract: Apparatuses and methods are presented relating to a plurality of current sources for generating a plurality of first bias currents to drive a plurality of LEDs and a plurality of measurement circuits for obtaining a plurality of first voltage measurements for the LEDs during a first test cycle. The current sources are further configurable to generate a plurality of second bias currents for driving the LEDs, and the measurement circuits are further configurable to obtain a plurality of second voltage measurements for the plurality of LEDs, during a second test cycle. A memory device is configured to store the first and second bias currents and first and second voltage measurements as a current-voltage (I-V) performance characteristic.

Abstract: Apparatuses and methods are presented relating to a plurality of current sources for generating a plurality of first bias currents to drive a plurality of LEDs and a plurality of measurement circuits for obtaining a plurality of first voltage measurements for the LEDs during a first test cycle. The current sources are further configurable to generate a plurality of second bias currents for driving the LEDs, and the measurement circuits are further configurable to obtain a plurality of second voltage measurements for the plurality of LEDs, during a second test cycle. A memory device is configured to store the first and second bias currents and first and second voltage measurements as a current-voltage (I-V) performance characteristic.

Abstract: In an embodiment, a headset display device includes a central processor and multiple projector integrated circuits each coupled to the central processor and configured to process image data. Each projector integrated circuit includes multiple first integrated circuits, each including a light emitter array. Each projector integrated circuit includes a second integrated circuit coupled to the multiple first integrated circuits. The second integrated circuit includes a graphics processor configured to generate transformed image data correcting for geometrical or brightness distortions and (2) is configured to provide the transformed image data to the multiple first integrated circuits for display.

Abstract: Techniques are described for operating a display system comprising a light source and a scanning assembly. The light source includes a plurality of emitters arranged in a column and circuitry configured to drive the emitters based on image data. The scanning assembly includes a reflective surface facing the light source, the reflective surface being rotatable in at least one dimension. A control signal including periodic, non-linear pulses causes the reflective surface to rotate through a range of scan angles, thereby forming an output image based on reflection of emitted light. The image data is supplied to the light source in synchronization with the rotational movement of the reflective surface. Changes in rotation speed due to the non-linear nature of the control signal are compensated for by adjusting emission durations for different rows to provide different emission durations at different times based on changes in the linearity of the control signal.

Abstract: Systems and methods for controlling a display apparatus are provided. In one example, an apparatus comprises a display comprising a plurality of light emitting diodes (LED), a display control circuit configured to generate display control signals, and a test module configured to generate test control signals. In a test operation mode, at least one LED of the plurality of LEDs is configured to be controlled by the test control signals from the test module to conduct at least one test output current. The test module can determine electrical characteristics of the at least one LED based on the at least one test output current. The display control circuit can adjust the display control signals based on the electrical characteristics of the at least one LED.

Abstract: A head mounted display (HMD) system includes a light source, a scanning mirror assembly, and an output screen. The light source includes source elements that emit image light. The scanning mirror assembly scans the image light at least along one dimension to form tiled portions of scanned image light of an output image. The scanning mirror assembly directs at least one of the tiled portions of the output image to a first position, and redirects at least one of the tiled portions of the output image to a second position adjacent to the first position. The scanning mirror assembly includes scanning mirrors operating within a first range of scanning frequencies along a slow axis and a second range of scanning frequencies along a fast axis. The output screen outputs a tiled image light to an eyebox region using the scanned image light.