An optical sensor for an aircraft includes two detectors, a light source, and a controller. The detectors are oriented along detector paths and have tilt angles and fields of view. The detectors are configured to detect light reflected from an illumination volume and to generate detector signals that correspond to intensities of detected light. The tilt angles are equal such that each detector is oriented in an opposite direction within a plane containing a light source path and the detector paths. The light source is oriented along the light source path and is configured to illuminate the illumination volume which overlaps with the fields of view within a predetermined distance range. The controller is configured to receive the detector signals, detect whether a cloud is present based upon the detector signals, determine a cloud phase, and calculate a density of the detected cloud.

The present disclosure provides an optical display system and method, and a display device. The optical display system includes: a display screen; a light split member configured to split light from the display screen into a first polarized light and a second polarized light with different polarization directions; a first optical waveguide configured to guide the first polarized light to a light exit side of the optical display system; and a second optical waveguide located at a light exit side of the first optical waveguide, spaced apart from the first optical waveguide, and configured to at least partially transmit the first polarized light and guide the second polarized light to the light exit side of the optical display system.

The present disclosure provides an optical display system and method, and a display device. The optical display system includes: a display screen; a light split member configured to split light from the display screen into a first polarized light and a second polarized light with different polarization directions; a first optical waveguide configured to guide the first polarized light to a light exit side of the optical display system; and a second optical waveguide located at a light exit side of the first optical waveguide, spaced apart from the first optical waveguide, and configured to at least partially transmit the first polarized light and guide the second polarized light to the light exit side of the optical display system.

An active display can be used in a theatre with reduced screen-door effect. For example, the active display can have a structure, such as a diffuser structure, or a diffuser and mask structure, that can have, or appear to have, transmissive areas and opaque areas to reduce the audience from detecting gaps or other non-light sources in the active display. The active display may additionally or alternatively have audio ports to allow sound to pass through the active display and appear to the audience as if the sound is coming from the active display.

An active display can be used in a theatre with reduced screen-door effect. For example, the active display can have a structure, such as a diffuser structure, or a diffuser and mask structure, that can have, or appear to have, transmissive areas and opaque areas to reduce the audience from detecting gaps or other non-light sources in the active display. The active display may additionally or alternatively have audio ports to allow sound to pass through the active display and appear to the audience as if the sound is coming from the active display.

A display system based on a four-dimensional light field, and a display method therefor. The display system includes: a light source module (11), a display panel (12), and a light conduction component (13), wherein the light source module (11) includes a plurality of light sources arranged in an array; and the display panel (12) is a reflective liquid crystal display panel, and the display panel (12) includes a plurality of pixel units arranged in an array. Light emitted by the light sources in the light source module (11) irradiates the pixel units in the display panel (12); and the pixel units in the display panel (12) transmit the received light to a target position by means of the light conduction component (13).

A polarizing rotation device including a rotation shaft, a driving element and a polarizing element is provided. The driving element is configured to drive the rotation shaft to rotate. The polarizing element is connected to the rotation shaft and is disposed on a transmission path of at least one beam, where the driving element is configured to drive the polarizing element to rotate sequentially while taking the rotation shaft as a rotation central axis, and when the polarizing element is rotated, the at least one beam penetrates through the polarizing element, and the at least one beam penetrating through the polarizing element has different polarization states at different time. Therefore, when a projection device is in a polarized stereoscopic mode, a color or brightness of a display image is uniform, and a user observes a 3D display image with good uniformity.

A polarizing rotation device including a rotation shaft, a driving element and a polarizing element is provided. The driving element is configured to drive the rotation shaft to rotate. The polarizing element is connected to the rotation shaft and is disposed on a transmission path of at least one beam, where the driving element is configured to drive the polarizing element to rotate sequentially while taking the rotation shaft as a rotation central axis, and when the polarizing element is rotated, the at least one beam penetrates through the polarizing element, and the at least one beam penetrating through the polarizing element has different polarization states at different time. Therefore, when a projection device is in a polarized stereoscopic mode, a color or brightness of a display image is uniform, and a user observes a 3D display image with good uniformity.

A near-eye display device and a near-eye display method are provided. In the near-eye display device and method, displaying a first image and a second image in different time periods by using a display portion; converting light of the first image to first linearly polarized light and converting light of the second image to second linearly polarized light by using a polarization conversion portion, a polarization direction of the first linearly polarized light being different from that of the second linearly polarized light; receiving the first linearly polarized light and the second linearly polarized light, and causing them to be emitted towards different directions by using a polarization splitting portion; and transmitting the first linearly polarized light and transmitting the second linearly polarized light by using an image light transmission portion.

A near-eye display device and a near-eye display method are provided. In the near-eye display device and method, displaying a first image and a second image in different time periods by using a display portion; converting light of the first image to first linearly polarized light and converting light of the second image to second linearly polarized light by using a polarization conversion portion, a polarization direction of the first linearly polarized light being different from that of the second linearly polarized light; receiving the first linearly polarized light and the second linearly polarized light, and causing them to be emitted towards different directions by using a polarization splitting portion; and transmitting the first linearly polarized light and transmitting the second linearly polarized light by using an image light transmission portion.