Beam angle sensor in virtual/augmented reality system
A virtual image generation system for use by an end user comprises a projection subsystem configured for generating a collimated light beam, and a display configured emitting light rays in response to the collimated light beam to display a pixel of an image frame to the end user. The pixel has a location encoded with angles of the emitted light rays. The virtual image generation system further comprises a sensing assembly configured for sensing at least one parameter indicative of at least one of the emitted light ray angles, and a control subsystem configured for generating image data defining a location of the pixel, and controlling an angle of the light beam relative to the display based on the defined location of the pixel and the sensed parameter(s).
1. A display system comprising:
a projection assembly configured to emit light;
a sensing assembly optically coupled to the projection assembly and configured to measure at least one parameter of light incident thereon;
a control subsystem in communication with the projection assembly and the sensing assembly, the control subsystem configured to:
generate image data defining a color, intensity, and location of a pixel of virtual content;
cause the projection assembly to emit light corresponding to the pixel as defined by the image data;
receive measurement data from the sensing assembly indicating at least one parameter of the light emitted by the projection assembly;
modify the image data based at least in part on the measurement data received from the sensing assembly; and
cause the projection assembly to emit light corresponding to the pixel as defined by the modified image data.
2. The display system of claim 1 further comprising a waveguide apparatus optically coupled to the projection assembly.
3. The display system of claim 2 , wherein the sensing assembly is optically coupled to the projection assembly at least in part by way of the waveguide apparatus.
4. The display system of claim 2 further comprising a frame structure configured to be worn about a head of a user, the frame structure carrying the waveguide apparatus.
5. The display system of claim 4 , wherein the sensing assembly is configured to be positioned outside of a field of view (FOV) of the user.
6. The display system of claim 2 , wherein the waveguide apparatus comprises one or more planar optical waveguides.
7. The display system of claim 1 , wherein the control subsystem is further configured to:
determine, based on the measurement data received from the sensing assembly, an angle at which light corresponding to the pixel as defined by the image data is incident the sensing assembly,
wherein to modify the image data based at least in part on the measurement data received from the sensing assembly, the control subsystem is configured to:
modify the image data based at least in part on the determined angle and an angle corresponding to the location of the pixel as defined by the image data.
8. The display system of claim 7 , wherein the control subsystem is further configured to:
compute a discrepancy between the determined angle and the angle corresponding to the location of the pixel as defined by the image data,
wherein to modify the image data based at least in part on the determined angle and the angle corresponding to the location of the pixel as defined by the image data, the control subsystem is configured to:
modify the image data based at least in part on the computed discrepancy.
9. The display system of claim 1 , wherein to measure at least one parameter of light incident thereon, the sensing assembly is configured to measure an absolute intensity of light incident thereon.
10. The display system of claim 1 , wherein the control subsystem comprises a graphics processing unit (GPU).
11. The display system of claim 1 , wherein the projection assembly comprises red, green, and blue light sources configured to produce red, green, and blue light, respectively.
12. The display system of claim 11 , wherein to cause the projection assembly to emit light corresponding to the pixel as defined by the image data, the control subsystem is configured to:
control operation of the projection assembly to modulate an intensity of light produced by each light source in a manner so as to emit light corresponding to the pixel as defined by the image data.
13. The display system of claim 12 , wherein to cause the projection assembly to emit light corresponding to the pixel as defined by the modified image data, the control subsystem is configured to:
control operation of the projection assembly to modulate an intensity of light produced by each light source in a modified manner so as to emit light corresponding to the pixel as defined by the modified image data.