An optical film stack including a DOE, a first detecting circuit layer, a liquid crystal changeable diffuser, and a conductive structure is provided. The first detecting circuit layer is disposed on the DOE. The liquid crystal changeable diffuser is disposed beside the DOE and includes a first transparent substrate, a second detecting circuit layer, a second transparent substrate, a third detecting circuit layer, and a liquid crystal layer. The second detecting circuit layer is disposed on the first transparent substrate. The second transparent substrate is disposed beside the first transparent substrate. The third detecting circuit layer is disposed on the second transparent substrate. The liquid crystal layer is disposed between the first transparent substrate and the second transparent substrate. The conductive structure electrically connects the first detecting circuit layer, the second detecting circuit layer, and the third detecting circuit layer.

An optical film stack including a DOE, a first detecting circuit layer, a liquid crystal changeable diffuser, and a conductive structure is provided. The first detecting circuit layer is disposed on the DOE. The liquid crystal changeable diffuser is disposed beside the DOE and includes a first transparent substrate, a second detecting circuit layer, a second transparent substrate, a third detecting circuit layer, and a liquid crystal layer. The second detecting circuit layer is disposed on the first transparent substrate. The second transparent substrate is disposed beside the first transparent substrate. The third detecting circuit layer is disposed on the second transparent substrate. The liquid crystal layer is disposed between the first transparent substrate and the second transparent substrate. The conductive structure electrically connects the first detecting circuit layer, the second detecting circuit layer, and the third detecting circuit layer.

A filter module having at least one filter region is provided. The filter module is pervious to a first color light with a first waveband in a converted light, and filters a second color light with a second waveband in the converted light. The filter module includes an absorptive filter and a dichroic film. The absorptive filter is located at the at least one filter region, and configured to absorb the second color light with the second waveband. The dichroic film is located on the absorptive filter, and is pervious to the first color light and reflects the second color light. The absorptive filter is configured to absorb the second color light coming from the dichroic film, and is pervious to the first color light. The first waveband is greater than a first wavelength, and the second waveband is smaller than the first wavelength. A projection device is also provided.

An information processing apparatus including a determination unit that acquires a first detection result and a second detection result. The first detection result indicates information regarding at least one of a position and an orientation of a projection unit. The projection unit causes display information to be displayed by projecting the display information onto a projection plane. The second detection result indicates a spatial positional relationship between the projection unit and the projection plane. The information processing apparatus further includes a control unit that controls an operation of the projection unit on a basis of the first detection result and the second detection result.

To safely project a desired projection image in any projection area, provided is a projection system including: a projection device projecting light forming display information in a projection area; an imaging device capturing a range including the projection area; and a control device controlling to cause the projection device to project light and the imaging device to capture the projection area. The control device includes: an analysis circuit accumulating image information about the projection area captured by the imaging device and detects an abnormality in the projection area by comparing any one piece of accumulated image information about the projection area with image information about the projection area most recently captured by the imaging device; and a safety control circuit executing safety control to change a projection condition for the projection device when an abnormality is detected in the projection area by the analysis circuit.

In a projector, a first fixation section and a second fixation section are formed at two places located at a distance in an optical axis direction in a lens barrel of a projection optical system. A holding member has contact with the first fixation section from an optical axis direction-rear side, and is fixed, an optical component housing of an illumination light guide optical system has contact with the holding member from the optical axis direction-rear side, and is fixed. A light modulating/combining optical system for generating image light has contact with the second fixation section from the optical axis direction-rear side and is fixed. In other words, the light modulating/combining optical system is directly fixed to the lens barrel without the intervention of the holding member for fixing the illumination light guide optical system to the lens barrel.

A HUD 100 includes a R light source 12r, a G light source 12g, and a B light source 12b; collimating lenses 13r, 13g, and 13b that are arranged forwardly of the light sources; fly-eye lenses 16 and 17 that are arranged side by side on an optical path of light that exits from the collimating lenses; a light modulation element 20 that, based on image information, performs spatial modulation on light that has passed through the fly-eye lenses; a projection optical system 50 that projects image light onto a projection surface 7, the image light acquired by the spatial modulation by the light modulation element; photodetection elements PD1 and PD2 that are fixed to a portion of the fly-eye lens 16; and an image light control unit 40B that controls a brightness distribution of the image light based on a brightness of light detected by each of the photodetection elements.

A projector includes a projection section that projects first light representing an image on a projection surface, a detection section that detects whether or not an enclosure member that encloses part of an area through which the first light projected via the projection section passes has been attached to the projector, and an adjustment section that adjusts the intensity of the first light based on the result of the detection performed by the detection section.

The disclosure provides a projection system and a projection method using the projection system. The projection system can project a projection beam toward the projection target. The projection system includes an image capturing device and a projection device. The image capturing device can capture an appearance image containing the path target as image information. The projection device is electrically connected to the image capturing device. The projection device can provide a projection beam, and the projection beam includes a first beam and a second beam. The path target is located on the transmitting path of the first beam, and the second beam is projected to the projection target. The projection device can adjust the luminous intensity of the first beam according to the image information, so as to reduce the luminous intensity of the first beam.

[Object] To control operation related to the projection of a video in accordance with usage conditions in a more favorable aspect. [Solution] An information processing apparatus including: an acquisition unit configured to acquire a first detection result indicating information regarding at least one of a position and an orientation of a projection unit that causes display information to be display by projecting the display information onto a projection plane, and a second detection result indicating a spatial positional relationship between the projection unit and the projection plane; and a control unit configured to control an operation of the projection unit on a basis of the first detection result and the second detection result.