A display system includes a light projection device operatively coupled to an image source that generates image data. The system also includes a composite variable focus element (VFE) assembly operatively coupled to the light projection device, the composite VFE assembly comprising a first VFE arranged in series with a second VFE to provide image frames corresponding to the image data for display. The first VFE is configured to switch between focal states within a first focal range and with a first switching response time. The second VFE is configured to switch between focal states within a second focal range and with a second switching response time. The first focal range is greater than the second focal range. The first switching response time is slower than the second switching response time.

A projection optical system applicable to a head-up display device mounted on an automobile includes an image generation unit, a first reflection unit, a light splitting device, a first lens, a second reflection unit, and a second lens that are successively arranged in a light exit direction; and a controller configured to control, based on timing, an image emitted from the connected image generation unit and light exiting from the connected light splitting device. When the image generation unit emits the first image, the light exits only from the light reflection side of the light splitting device, such that the first image is emitted and imaged through the first lens. When the image generation unit emits the second image, the light exits only from the light transmission side of the light splitting device, such that the second image is emitted and imaged through the second lens.

A projection optical system applicable to a head-up display device mounted on an automobile includes an image generation unit, a first reflection unit, a double-telecentric lens, a light splitting device arranged on image side of the double-telecentric lens, a first lens, a second reflection unit, and a second lens that are successively arranged in light exit direction; and a controller configured to control, based on timing, an image emitted from the image generation unit and light exiting from the light splitting device. When the image generation unit emit the first image, the light exit only from light reflection side of the light splitting device, and when the image generation unit to emit the second image, the light to exit only from light transmission side of the light splitting device, such that the first and second image are emitted and imaged through the first and second lens.

Methods, apparatus, devices, and systems for displaying three-dimensional objects by individually diffracting different colors of light are provided. In one aspect, a system includes a display having a plurality of display elements and an optical device configured to diffract a plurality of different colors of light to the display. The optical device is configured such that, when the plurality of different colors of light is incident on the optical device, the optical device separates light of individual colors of the different colors while suppressing crosstalk between the different colors.

Methods, apparatus, devices, and systems for displaying three-dimensional objects by individually diffracting different colors of light are provided. In one aspect, a system includes a display having a plurality of display elements and an optical device configured to diffract a plurality of different colors of light to the display. The optical device is configured such that, when the plurality of different colors of light is incident on the optical device, the optical device separates light of individual colors of the different colors while suppressing crosstalk between the different colors.

A display apparatus for presenting three-dimensional imagery, including an optical combiner having a first side, a second side, a third side and a fourth side. The second side is opposite to the first side and the fourth side being is opposite to the third side. Optical combiner further includes a first semi-transparent reflective portion arranged to reflect light incoming from the first side towards the fourth side and a second semi-transparent reflective portion arranged to reflect light incoming from the second side towards the fourth side. Light incoming from the third side passes through the first semi-transparent reflective portion and the second semi-transparent reflective portion towards the fourth side. The display apparatus further includes of a first display, a second display and a third display arranged at a first distance, a second distance and a third distance from the first side, the second side and the third side of the optical combiner, respectively, wherein a first image, a second image and a third image rendered at the first display, the second display and the third display are presented at a first focal distance, a second focal distance and a third focal distance, respectively, thereby creating the three-dimensional image.

A display apparatus for presenting three-dimensional imagery, including an optical combiner having a first side, a second side, a third side and a fourth side. The second side is opposite to the first side and the fourth side being is opposite to the third side. Optical combiner further includes a first semi-transparent reflective portion arranged to reflect light incoming from the first side towards the fourth side and a second semi-transparent reflective portion arranged to reflect light incoming from the second side towards the fourth side. Light incoming from the third side passes through the first semi-transparent reflective portion and the second semi-transparent reflective portion towards the fourth side. The display apparatus further includes of a first display, a second display and a third display arranged at a first distance, a second distance and a third distance from the first side, the second side and the third side of the optical combiner, respectively, wherein a first image, a second image and a third image rendered at the first display, the second display and the third display are presented at a first focal distance, a second focal distance and a third focal distance, respectively, thereby creating the three-dimensional image.

Some implementations of the disclosure are directed to modulating a number roundtrips that light travels within a cavity to modulate optical depth. In one implementation, a display system includes: a display configured to emit light corresponding to an image; a first optical component positioned in front of the display, the first optical component configured to pass the light to a field evolving cavity (FEC); and the FEC, where the FEC includes a cavity entrance and a cavity exit, the cavity entrance configured to receive the light passed by the first optical component, the FEC configured with a polarization clock that modulates a number of round trips the light travels within the FEC, between the cavity entrance and the cavity exit, by changing a polarization of the light during each round trip.

Some implementations of the disclosure are directed to modulating a number roundtrips that light travels within a cavity to modulate optical depth. In one implementation, a display system includes: a display configured to emit light corresponding to an image; a first optical component positioned in front of the display, the first optical component configured to pass the light to a field evolving cavity (FEC); and the FEC, where the FEC includes a cavity entrance and a cavity exit, the cavity entrance configured to receive the light passed by the first optical component, the FEC configured with a polarization clock that modulates a number of round trips the light travels within the FEC, between the cavity entrance and the cavity exit, by changing a polarization of the light during each round trip.

The present application relates to a linear light source using ultraviolet light emitting diodes (LEDs), and a photopolymer 3D printer comprising the linear light source. The linear light source may include a substrate distanced from a polymer case of the photopolymer 3D printer and an ultraviolet LED array in which a plurality of ultraviolet LEDs, which project ultraviolet rays toward the polymer case, are arranged on the substrate in multiple rows in the X-axis direction. The arrangement of the multiple columns in the Y-axis direction is at an oblique angle to the multiple rows.