An electronic device comprises a projector that is configured to project an image and a control unit. The control unit is configured to control an orientation of the image to be projected to a first orientation and onto a first surface when the electronic device is in a first attitude, and to control the orientation of the image to be projected to a second orientation different from the first orientation and onto a second surface different from the first surface when the electronic device is in a second attitude different from the first attitude.

A method of generating uniform large-scale optical focus arrays (LOT As) with a phase spatial light modulator includes identifying and removing undesired phase rotation in the iterative Fourier transform algorithm (IFTA), thereby producing computer-generated holograms of highly uniform LOT As using a reduced number of iterations as compared to a weighted Gerch-berg-Saxton algorithm. The method also enables a faster compensation of optical system-induced LOT A intensity inhomogeneity than the conventional IFTA.

Hand gestures may be performed to control a visual projector. When a human hand is placed into a projection field of the visual projector, the visual projector responds to hand gestures performed by the human hand. The human hand, for example, may gesture to rotate a projected image or to correct the projected image. The visual projector may thus manipulate and/or correct the projected image in response to the gesture performed by the human hand.

A projector includes a polarization changing mechanism and a polarized beam splitter. The polarization changing mechanism is movable. A first polarized beam is configured to pass or not pass through the polarization changing mechanism. The first polarized beam transforms into a second polarized beam when the first polarized beam passes through the polarization changing mechanism. The polarized beam splitter has a light splitting surface. The first polarized beam enters the polarized beam splitter and is guided by the light splitting surface to travel in a first direction, when the first polarized beam does not pass through the polarization changing mechanism. The second polarized beam enters the polarized beam splitter and is guided by the light splitting surface to travel in the first direction or a second direction, when the first polarized beam passes through the polarization changing mechanism and transforms into the second polarized beam.

A method of controlling a display system including the steps of projecting, by one of the first projectors, a first image in one area, projecting, by one of the second projectors, a second image in the one area, estimating, by the control device, brightness of the plurality of first images and brightness of the plurality of second images, identifying, by the control device, a first dark image as the darkest image and a first adjustment target image, and identifying a second dark image as the darkest image and a second adjustment target image, and controlling, by the control device, a projector to thereby approximate the brightness of the first adjustment target image to the brightness of the first dark image, and controlling a projector to thereby approximate the brightness of the second adjustment target image to the brightness of the second dark image.

A discharge lamp driving device includes a discharge lamp driving unit configured to supply a driving current to a discharge lamp including electrodes, a controller configured to control the discharge lamp driving unit, and a voltage detection unit configured to detect an inter-electrode voltage of the discharge lamp, in which the controller controls the discharge lamp driving unit so that the driving current includes a hybrid period in which a first period for supplying an AC current with a first frequency to the discharge lamp and a second period for supplying a DC current to the discharge lamp are alternately repeated, in which the first frequency includes a plurality of different frequencies, and in which the controller changes the first frequency on the basis of at least one of the detected inter-electrode voltage and driving power supplied to the discharge lamp.

A wavelength conversion element includes: a substrate; an intermediate layer that is provided on the substrate and has a refractive index less than a refractive index of the substrate; a dichroic layer that is provided on the intermediate layer; and a fluorescent layer that is provided on the dichroic layer and that is excited by light with a first wavelength band and thereby emits light with a second wavelength band different from the first wavelength band.

A projection display unit (1) includes a projection optical system (10A), a polarization separation device (15), and a detection optical system (10B). The projection optical system includes an illuminator (11), a projection lens (16), and a light valve (12) that modulates illumination light supplied from the illuminator on the basis of an image signal, and outputs the modulated illumination light toward the projection lens. The polarization separation device (15) is disposed between the light valve and the projection lens. The polarization separation device separates entering light into a first polarized component and a second polarized component, and outputs the first polarized component and the second polarized component in respective directions that are different from each other. The detection optical system includes an imaging device (13) and a reduction optical system (14). The imaging device is disposed in a position that is optically conjugate with a position of the light valve. The reduction optical system is disposed between the imaging device and the polarization separation device. The imaging device receives, via the projection lens and the polarization separation device, light based on detection invisible light. A transmittance adjuster is provided between the polarization separation device and the imaging device. The transmittance adjuster adjusts transmittance of at least part of a bundle of passing light rays derived from the invisible light.

An image correction method performed by a projector, the method including projecting a second image onto a projection surface, the second image is acquired by reducing a first image containing a plurality of candidate points that are candidates for display position correction to a size that falls within a projection area that is the largest area over which the projector is capable of projection, accepting a first input to select a target point that is a display position correction target out of the plurality of candidate points in the state in which the second image is projected on the projection surface, projecting a third image onto the projection surface, the third image is acquired by enlarging the second image to the size of the first image after accepting the first input, accepting a second input to change the display position of the target point in the state in which the third image is projected on the projection surface, and projecting a projection image acquired by correcting the shape of an input image based on the second input onto the projection surface.

A laser display system includes a red light semiconductor laser module (1), a green light semiconductor laser module (2), a blue light semiconductor laser module (3), a decoherence device (7, 8, 9), light valves (12, 13, 14), collimating and shaping devices (4, 5, 6), a heat dissipating modules (16-1, 16-2, 16-3), a temperature control module (17) and a semiconductor laser control module (18). The wavelength range output by the red light semiconductor laser module (1) is from 635 nm to 670 nm; the wavelength range output by the green light semiconductor laser module (2) is from 515 nm to 530 nm; the wavelength range output by the blue light semiconductor laser module (3) is from 440 nm to 460 nm.