MEMS scan controlled keystone and distortion correction

A MEMS scanned beam projector, comprising:

• a light source to emit a light beam;
• a scanning platform to redirect the light beam impinging on the platform;
• and
• a display controller to control the light source and the scanning platform to cause the scanning platform to scan the light beam in a vertical direction and a horizontal direction in a scan pattern to project an image onto a projection surface;
• wherein the display controller is configured to compensate for horizontal stretching in the projected image due to geometric distortion by modifying a start position and an end position of video path interpolation as a function of vertical scan position to reduce the horizontal stretching of the projected image, wherein the display controller is configured to compensate for aspect ratio distortion in the projected image by reducing an amplitude of vertical displacement of the scanning platform.

A method to compensate for image distortion in an image projected by a MEMS scanned beam projector, the method comprising:

• redirecting a light beam from a light source impinging on a scanning platform;
• controlling the light source and the scanning platform to cause the scanning platform to scan the light beam in a vertical direction and a horizontal direction in a scan pattern to project an image onto a projection surface;
• compensating for horizontal stretching in the projected image due to geometric distortion by modifying a start position and an end position of video path interpolation as a function of vertical scan position to reduce the horizontal stretching of the projected image;
• and
• adjusting an interpolation rate to correct for image distortion in the projected image.

A MEMS scanned beam projector, comprising:

• a light source to emit a light beam;
• a scanning platform to redirect the light beam impinging on the platform;
• and
• a display controller to control the light source and the scanning platform to cause the scanning platform to scan the light beam in a vertical direction and a horizontal direction in a scan pattern to project an image onto a projection surface, where the image includes a plurality of pixels arranged in a plurality of horizontal lines;
• wherein the display controller is configured to compensate for horizontal stretching in the projected image due to geometric distortion by adjusting a horizontal interpolation rate between neighboring pixels in the plurality of pixels such that horizontal interpolation spacing operates as a function of vertical scan position and by modifying a start position and a stop position of the horizontal lines as a function of vertical scan position to reduce the horizontal stretching.