Embodiments of the disclosure provide a projection display apparatus comprising: a light source for emitting a light beam; a first light path configured to project the light beam emitted from the light source to a first display position; a second light path configured to project the light beam emitted from the light source to a second display position; a light patch switching device configured to switch the light beam emitted from the light source between the first light path and the second light path; and a light modulation device through which both the first light path and the second light path pass, wherein the light modulation device is configured to modulate the light beam passing therethrough to generate a display image.

A retroreflector system including an outer body panel coupled to a vehicle, wherein the outer body panel is configured to allow a radar signal originating from an external radar device to pass through the outer body panel. The retroreflector system also includes a plurality of retroreflectors embedded in the vehicle, where the plurality of retroreflectors is configured to reflect the signal to the external signal source as a reflected signal, and where the plurality of retroreflectors is configured to have a peak reflectivity for a radar wavelength range or a light detection and ranging (lidar) wavelength range.

A retroreflector device is described, which includes a lens component operable for focusing radiation, which is incident thereto at an angle of incidence. The retroreflector also includes a mirror component operable for reflecting the radiation focused by the lens component back along the angle of incidence. The lens component and/or the mirror component includes a quasi-periodic array of elements, each of which comprises a dimension smaller than a wavelength of the radiation.

A retroreflector device is described, which includes a lens component operable for focusing radiation, which is incident thereto at an angle of incidence. The retroreflector also includes a mirror component operable for reflecting the radiation focused by the lens component back along the angle of incidence. The lens component and/or the mirror component includes a quasi-periodic array of elements, each of which comprises a dimension smaller than a wavelength of the radiation.

A coating method of reflective film is first to prepare a glass beads film and then select a color to be coated. The color is composed of plural primary colors in fixed ratio, making the color have a standard ratio, which is obtainable from an original database. Next, ratios of the primary colors are respectively adjusted to form a printing ratio according to color fastness, permeability and light barrier property of each primary color attached to the glass beads and then, each primary color is orderly spray coated on the glass beads film to form a coating layer with micro-printing technique in accordance with the printing ratio, thus completing manufacturing of a reflective film with high transmittance and high wide angle.

A coating method of reflective film is first to prepare a glass beads film and then select a color to be coated. The color is composed of plural primary colors in fixed ratio, making the color have a standard ratio, which is obtainable from an original database. Next, ratios of the primary colors are respectively adjusted to form a printing ratio according to color fastness, permeability and light barrier property of each primary color attached to the glass beads and then, each primary color is orderly spray coated on the glass beads film to form a coating layer with micro-printing technique in accordance with the printing ratio, thus completing manufacturing of a reflective film with high transmittance and high wide angle.

A retroreflector system including an outer body panel coupled to a vehicle, wherein the outer body panel is configured to allow a radar signal originating from an external radar device to pass through the outer body panel. The retroreflector system also includes a plurality of retroreflectors embedded in the vehicle, where the plurality of retroreflectors is configured to reflect the signal to the external signal source as a reflected signal, and where the plurality of retroreflectors is configured to have a peak reflectivity for a radar wavelength range or a light detection and ranging (lidar) wavelength range.

A retroreflector system including an outer body panel coupled to a vehicle, wherein the outer body panel is configured to allow a radar signal originating from an external radar device to pass through the outer body panel. The retroreflector system also includes a plurality of retroreflectors embedded in the vehicle, where the plurality of retroreflectors is configured to reflect the signal to the external signal source as a reflected signal, and where the plurality of retroreflectors is configured to have a peak reflectivity for a radar wavelength range or a light detection and ranging (lidar) wavelength range.

The image display apparatus includes an optical system causing a light flux entering from an original image by being transmitted through a fifth surface to reflect at a fourth surface, a third surface, a first surface and a second surface and then cause the light flux to be transmitted through the first surface and exit toward an exit pupil, causing the light flux to form an intermediate image and causing optical paths to intersect with each other. The optical system satisfies 0.62L12/f5.00 and 1.80L45/L125.00. When a distance between hit points of a central-view-angle principal ray on the surfaces is referred to as a hit point distance, L45 represents a hit point distance between the fourth and fifth surfaces, L12 represents a hit point distance between the first and second surfaces, and f represents a focal length of the optical system.

The image display apparatus includes an optical system causing a light flux entering from an original image by being transmitted through a fifth surface to reflect at a fourth surface, a third surface, a first surface and a second surface and then cause the light flux to be transmitted through the first surface and exit toward an exit pupil, causing the light flux to form an intermediate image and causing optical paths to intersect with each other. The optical system satisfies 0.62L12/f5.00 and 1.80L45/L125.00. When a distance between hit points of a central-view-angle principal ray on the surfaces is referred to as a hit point distance, L45 represents a hit point distance between the fourth and fifth surfaces, L12 represents a hit point distance between the first and second surfaces, and f represents a focal length of the optical system.