Dynamic distortion correction for optical compensation
A distortion calibration system generates a distortion map for a head-mounted display (HMD). The system includes a camera that takes pictures of a test pattern displayed by the HMD. The images are taken at different camera positions and/or states of the HMD. The system determines a distortion map using the captured images, and uploads it to the HMD as part of, e.g., an optical model. The HMD comprises an electronic display, an eye tracking unit, an optics block, and a module. The module estimates distortion values based on eye tracking information from the eye tracking unit, an optical model, and a state of the HMD (e.g., a distance between the optics block and the electronic display). The module determines an adjusted state of the HMD using the estimated distortion values, the eye tracking information, and the optical model, and adjusts the state of the HMD to the adjusted state.
1. A head mounted display (HMD) comprising:
an electronic display configured to present images to a user of the HMD;
an eye tracking unit configured to determine eye tracking information for one or more eyes of the user as the user views the images presented by the electronic display;
an optics block configured to modify the images presented by the electronic display when viewed by the user;
a distortion correction module configured to:
estimate one or more distortion values by inputting the eye tracking information and a state of the HMD into an optical model, wherein the HMD includes a plurality of states, and each state is associated with a different image plane for the electronic display,
determine an adjusted state of the HMD using one or more of the estimated distortion values, the eye tracking information, and the optical model, the adjusted state being different from the state, and
adjust the optical element in accordance with the adjusted state.
2. The HMD of claim 1 , wherein the distortion correction module is further configured to determine the adjusted state by:
using the optical model to determine a state of the HMD at which associated distortion values are less than a threshold distortion value.
3. The HMD of claim 1 , wherein the optical model is a distortion map that maps values for one or more types of distortion to the eye tracking information for each of the plurality of states of the HMD.
4. The HMD of claim 1 , wherein the optical model is a ray-tracing program that dynamically determines values for one or more types of distortion using the eye tracking information for each of the plurality of states of the HMD.
5. The HMD of claim 1 , wherein the distortion correction module is further configured to pre-distort the images presented by the electronic display to reduce the estimated distortion values based on the eye tracking information.
6. The distortion calibration system of claim 1 , wherein the distance between the electronic display and the optical element is adjusted by the optical element changing its position relative to the electronic display.
7. The distortion calibration system of claim 1 , wherein the distance between the electronic display and the optical element is adjusted by the electronic display changing its position relative to the optical element.