Monitoring position and orientation of a projector

A method implemented at a self-correcting projection system for monitoring or adjusting positions or orientations of a projector installed thereon, the method comprising:

• emitting an illumination light beam from an illumination light source;
• emitting a monitor light beam from a monitor light source;
• receiving at the projector the illumination light beam from the illumination light source and the monitor light beam from the monitor light source, the projector including a reflective spatial light modulator configured to modulate the illumination light beam and the monitor light beam to generate a projected combined light beam that contains a projected illumination light beam and a projected monitor light beam;
• projecting, by the projector, the illumination light beam into a projected illumination light beam;
• projecting, by the projector, the monitor light beam into a monitor light beam;
• propagating the projected illumination light beam over a first beam path in a first direction toward an eye of a user;
• propagating the projected monitor light beam over a second beam path toward a second direction toward a monitor camera;
• capturing, by the monitor camera, a monitor image corresponding to the monitor light beam;
• analyzing the monitor image to determine an orientation or a position of the monitor image;
• and
• in response to determining that the monitor image is not properly oriented or positioned,
• (1) adjust an orientation or a position of the projector, or
• (2) adjust an orientation or a position of the illumination image.

A head-mounted device, comprising:

• a first projection system configured to project a first image at a first eye of a user, the first projection system comprising:
• a first illumination light source configured to emit a first illumination light beam;
• a first monitor light source configured to emit a first monitor light beam;
• a first projector configured to receive the first illumination light beam from the first illumination light source and receive the first monitor light beam from the first monitor light source, the first projector including a reflective spatial light modulator configured to modulate the first illumination light beam and the first monitor light beam to generate a first projected combined light beam that contains a projected first illumination light beam and a projected first monitor light beam,
• the first projector also configured to project both the first illumination light beam and the first monitor light beam into a first projected combined light beam;
• a first display beam path configured to propagate a first portion of the first projected combined light beam in a first direction, the first portion of the first projected combined light beam containing at least a portion of the first illumination light beam projected by the first projector, causing the first eye of the user to see a first display image corresponding to the first illumination light beam;
• and
• a first monitor beam path configured to propagate a second portion of the first projected combined light beam in a second direction, the second portion of the first projected combined light beam containing at least a portion of the first monitor light beam projected by the first projector;
• a second projection system configured to project a second image at a second eye of the user, the second projection system comprising:
• a second illumination light source configured to emit a second illumination light beam;
• a second monitor light source configured to emit a second monitor light beam;
• a second projector configured to receive the second illumination light beam from the second illumination light source and receive the second monitor light beam from the second monitor light source, the first projector including a reflective spatial light modulator configured to modulate the second illumination light beam and the second monitor light beam to generate a second projected combined light beam that contains a projected second illumination light beam and a projected second monitor light beam,
• the second projector also configured to project both the second illumination light beam and the second monitor light beam into a second projected combined light beam;
• a second display beam path configured to propagate a third portion of the second projected combined light beam in a third direction, the third portion of the second projected combined light beam containing at least a portion of the second illumination light beam projected by the second projector, causing the second eye of the user to see a second display image corresponding to the second illumination light beam;
• and
• a second monitor beam path configured to propagate a fourth portion of the second projected combined light beam in a fourth direction, the fourth portion of the second projected combined light beam containing at least a portion of the second monitor light beam projected by the second projector;
• a monitor camera configured to:
• receive the second portion of the first projected combined light beam to capture a first monitor image corresponding to the first monitor light beam projected by the first projector;
• and
• receive the fourth portion of the second projected combined light beam to capture a second monitor image corresponding to the second monitor light beam projected by the second projector;
• one or more processors;
• and
• one or more computer-readable media having stored thereon computer-executable instructions that are structured such that, when the computer-executable instructions are executed by the one or more processors, the head-mounted device is configured to perform at least:
• analyze the first monitor image or the second monitor image to determine an orientation or a position of the first monitor image or the second monitor image;
• and
• in response to determining that at least one of the first monitor image or the second monitor image is not properly oriented or positioned,
• (1) adjust an orientation or a position of at least one of the first projector or the second projector, or
• (2) adjust an orientation or a position of at least one of the first illumination image or the second illumination image.