Patent attributes
A projecting method includes: outputting, by a projection display apparatus, a projected image to a projection screen through a shifting device, wherein the projected image includes multiple frames; outputting, by a processing circuit, a control signal to drive the shifting device to rotate multiple first angles along a first axis or to rotate multiple second angles along a second axis, wherein combination of the first and the second angles corresponds to multiple projected positions; and when the projection display apparatus outputs multiple frames sequentially, rotating the shifting device sequentially according to the control signal to make multiple frames projected to the corresponding one of projected positions, wherein a number of the first angles or the second angles is at least four.