A projection optical apparatus includes a projection system projecting light and including a resin lens, a degradation suppressor configured to suppress degradation of the resin lens, and a projection controller configured to control the degradation suppressor.

An image projector with a high optical efficiency projects an image at an arbitrary distance from an observer. The image projector includes an illumination module having at least one spatially coherent light source; a phase image generator with an array of optical phase shifting elements; an electronic image controller connected electrically to the phase image generator; and a waveguide which includes at least one embedded partial reflector. The waveguide may be positioned either between the illumination module and the waveguide, or between the waveguide and the observer. The phase image generator may include phase shifts for canceling speckle, correcting optical aberrations, and/or compensating interference caused by light rays having different optical path lengths.

A projector includes a main body and a projection lens. The main body includes a light source, liquid crystal panels that modulate light outputted from the light source, and a lens holder to and from which the projection lens is attachable and detachable. The projection lens projects the light modulated, and the lens holder includes a first lens holding mechanism and a second lens holding mechanism that hold the projection lens.

A projection device, a projection system and a method for calibrating projected image are provided. The projection device and an external projection device the same image source and respectively project an image and another image corresponding to the image source. The same portion of the image source where the two images overlap each other forms an overlapping area. The projection device includes a lens, a light shielding member and a processor. The light shielding member is disposed on the lens. The processor controls the light shielding member to selectively shade a partial area of the lens according to the brightness of the image source, wherein the partial area corresponds to the overlapping area.

A projective transformation matrix determination method includes receiving a change instruction to change a positional relationship among four feature points in a situation in which a projector projects a first projection image showing the four feature points onto a first area, causing the projector to project a second projection image showing the four feature points onto the first area in response to the change instruction, and determining a projective transformation matrix based on the coordinates of the four feature points in the second projection image and the coordinates of the four feature points in a first captured image generated by capturing, with a camera, an image of the first area where the second projection image is projected, the projective transformation matrix associating a projector coordinate system which defining the coordinates in an image projected by the projector with a camera coordinate system defining the coordinates in an image generated by the camera.

A projection apparatus includes a display element that displays an image, a projection optical system that forms a projection image by projecting the image, an imaging unit that includes an imaging optical system which images a first region including an optical axis of the projection optical system in the projection image, and an imaging element which captures an image formed by the imaging optical system, and a processor that controls focus adjustment on a second region not including the optical axis in the projection image based on information acquired from the imaging unit, in which a position of the projection image is changeable by changing a relative position between at least a part of the projection optical system and the display element, and a predetermined conditional expression is satisfied.

An object of the present invention is to provide a projection apparatus capable of appropriately performing control relating to a rotation state and/or a movement state of a projection lens. A projection apparatus according to an aspect of the present invention includes a housing; a light source; a control unit; and a projection lens attached to the housing, the projection lens having a holder, a detection unit that detects a rotation state of the holder, an emission optical system, and a locking mechanism unit that brings rotation of the holder into a locked state or an unlocked state. The projection lens is displaceable between a first position at which a rotation state of the holder is a housed state in which the emission optical system faces the housing and a second position at which the emission optical system does not face the housing by rotating the holder. The second position includes an upper position at which the emission optical system faces an upper side in a vertical direction. The control unit turns off the light source when a rotation state of the holder is the first position. The control unit turns on the light source when the rotation state of the holder is at the upper position. When the light source is turned on in the housed state in which the emission optical system faces the housing, the light emitted from the emission optical system hits the housing, and the temperatures of the projection lens and the housing may increase, which may cause an adverse effect. However, when the rotation state is the housed state, the control unit turns off the light source, thereby preventing the adverse effect.

There is provided a projection lens that is mounted on a housing of a projection device including an electro-optical element. The projection lens comprises an optical system through which light passes, a second holding unit through which light parallel to a second optical axis passes and which is moved rotationally with respect to the housing, a third holding unit through which light parallel to a third optical axis obtained from bending of the second optical axis passes and which is moved rotationally with respect to the second holding unit, an electric drive unit that electrically controls rotational movement of the second holding unit with respect to the housing, rotational movement of the third holding unit with respect to the second holding unit, or drive of the optical system, and a cover part that covers the electric drive unit.

In described examples, a geometric progression of structured light elements is iteratively projected for display on a projection screen surface. The displayed progression is for determining a three-dimensional characterization of the projection screen surface. Points of the three-dimensional characterization of a projection screen surface are respaced in accordance with a spacing grid and an indication of an observer position. A compensated depth for each of the respaced points is determined in response to the three-dimensional characterization of the projection screen surface. A compensated image can be projected on the projection screen surface in response to the respaced points and respective compensated depths.

A projection lens has a first rotary tube, a first fixed tube at which the first rotary tube is rotatably mounted, a first protrusion portion that is provided at the first rotary tube and that protrudes from the first rotary tube, and a first abutment surface that is provided at the first fixed tube and that abuts upon the first protrusion portion. The projection lens includes a first engaging portion at which the first protrusion portion and the first abutment surface include first engaging portions that face each other in a direction of a first incidence-side optical axis and a first pressing portion that presses the first protrusion portion against the first abutment surface.