A display apparatus of the present disclosure includes: a first optical system that generates illumination light whose light emitting luminance is variable; a light modulation unit that transmits the illumination light from the first optical system and whose transmissivity is variable; a second optical system that includes a light modulation device and optically modulates the illumination light from the first optical system by using a pulse width modulation technology, the illumination light having passed through the light modulation unit; and a control unit that controls the light emitting luminance of the illumination light from the first optical system and the transmissivity of the light modulation unit in any combination.

An optical device includes a phosphor wheel and two light sources. The phosphor wheel has two phosphor regions. The phosphor regions are located at different radial positions of the phosphor wheel and are not overlapped. Each of the phosphor regions has a plurality of color sections. The light sources emit two light beams so as to respectively provide two light spots on the phosphor wheel. During the rotation of the phosphor wheel, the light spots are located at the color sections having the same fluorescent characteristic respectively in the phosphor regions.

A projector of the present invention includes a light source unit including a semiconductor light emitting element and a color wheel and emitting lights in first and second wavelength ranges in time division, a display device receiving light source light to form image light, a projection optical system for projecting the image light onto a projection target, a delay time setting module for shifting a start timing of a color mixing period when the lights in the first and second wavelength ranges are emitted in a mixed fashion in a spoke period of the color wheel during which emissions of the lights in the first and second wavelength ranges are switched over based on an index indicating a brightness of light from the light source unit, and a light source driving module for driving the light source unit based on a setting set by the delay time setting module.

A laser projection apparatus includes a laser source, an optical engine and a projection lens. The optical engine includes a light homogenizing component. The laser source includes a light-emitting assembly, a combining component, a first lens, a phosphor wheel and a laser dimming component. The combining component includes a reflecting portion and a transmitting portion. The phosphor wheel includes a first region and a second region. The laser dimming component is located between the light-emitting assembly and the phosphor wheel, and configured to increase Etendue of a laser beam emitted by the light-emitting assembly and change a shape of a beam spot provided by the laser beam on the phosphor wheel, so as to make a beam spot provided by the laser beam and the fluorescent beam at a beam inlet of the light homogenizing component matched with a shape of the beam inlet of the light homogenizing component.

A light source apparatus includes a first light source that includes a plurality of first light emitters arranged in a row along a first direction and emits a first luminous flux, a second light source that includes a plurality of second light emitters arranged in a row along a second direction and emits a second luminous flux in a direction in which the first luminous flux is emitted, and a combiner that combines the first and second luminous fluxes with each other to produce combined light and outputs the combined light to an irradiated region. The combined light has a combined light intensity distribution in which a first region where a light intensity of the first luminous flux is maximized and a second region where a light intensity of the second luminous flux is maximized do not overlap with each other.

A projection processing device comprises a processor control unit that acquires, in response to acceptance of input information, projection position information associated with the input information, and instructs a projector to emit light or project an image enabling a user to identify a position based on the acquired projection position information.

A projection screen control method of one embodiment of the present disclosure includes irradiating a display member with first control light, and irradiating the display member with second control light, in which the irradiating the display member with the first control light and the irradiating the display member with the second control light are performed in sequence. The display member has a visible light transmittance or a visible light reflectance that varies depending on light, and contains a photochromic material, and the first control light and the second control light have different light intensities.

A method for operating a discharge lamp by modulating a current signal is presented. The discharge lamp is operated with at least two different frequencies. At first a probability distribution function for a first number of first frequency periods and a second number of second frequency periods is defined. Next, the first number of first frequency periods and the second number of second frequency periods are determined depending on the probability distribution function by at least one random number. The current signal is modulated by applying the first number of first frequency periods and the second number of second frequency periods to the current signal for operating the discharge lamp.

An aerial light show system includes aerial vehicles configured to move along paths consisting of positions while emitting light beams to present an aerial light show of a virtual 3D scene. Each aerial vehicle includes a light source configured to project multiple light beams in multiple specified directions, respectively, wherein the brightness and/or color of each of the multiple light beams is independently controllable. The aerial light show system includes a control system configured to control the movement of the aerial vehicles, to modify the brightness and/or color of (e.g., dim or turn off) a light beam of each aerial vehicle at each position projected in a specified direction that is occluded by the virtual 3D scene, and to not modify the brightness and/or color of a light beam of each aerial vehicle at each position projected in a specified direction that is not occluded by the virtual 3D scene.

An excitation light intensity control system, including a lighting part, an imaging part and a control part. The lighting part includes a light source; the imaging part includes a light modulator and a color conversion element; the excitation light emitted from the light source is imported to the light modulator for modulation; the modulated excitation light excites the color conversion element to produce multicolor excited light; the lighting part further includes a light recycling system used for recoupling part of the excitation light emitted from the light modulator to be incident to the light modulator; the control part includes a controller used for receiving original image data and controlling the intensity of the excitation light emitted from the light modulator and/or the light source.