A switchable optical assembly comprises a switchable waveplate configured to be electrically activated and deactivated to selectively alter the polarization state of light incident thereon. The switchable waveplate comprises first and second surfaces and a liquid crystal layer disposed between the first and second surfaces. The first liquid crystal layer comprises a plurality of liquid crystal molecules. Said first and second surfaces may be curved. Said plurality of liquid crystal molecules may vary in tilt with respect to said first and second surfaces with outward radial distance from an axis through said first and second surfaces and said liquid crystal layer in a plurality of radial directions. The switchable waveplate additionally comprises a first plurality of electrodes to apply an electrical signal across said first liquid crystal layer.

A novel detachable holographic apparatus incorporates a dedicated upper shelf section that orients a portable electronic device's display screen to face downward after being inserted into the dedicated upper shelf section of the apparatus. The upper shelf section is created with a smartphone holder made of a rectangular center opening surrounded by a surrounding frame. The rectangular center opening allows the portable electronic device's display screen to project an image downward from the dedicated upper shelf section. The novel detachable holographic apparatus also incorporates a transparent display sheet or a one-way mirror sheet underneath the dedicated upper shelf section at a 45-degree angle relative to the surface of the portable electronic device's display screen, which in turn engender partial optical refractions and/or reflections of the image originating from the portable electronic device's display screen to form a hologram near the transparent display sheet or the one-way mirror sheet.

A novel detachable holographic apparatus incorporates a dedicated upper shelf section that orients a portable electronic device's display screen to face downward after being inserted into the dedicated upper shelf section of the apparatus. The upper shelf section is created with a smartphone holder made of a rectangular center opening surrounded by a surrounding frame. The rectangular center opening allows the portable electronic device's display screen to project an image downward from the dedicated upper shelf section. The novel detachable holographic apparatus also incorporates a transparent display sheet or a one-way mirror sheet underneath the dedicated upper shelf section at a 45-degree angle relative to the surface of the portable electronic device's display screen, which in turn engender partial optical refractions and/or reflections of the image originating from the portable electronic device's display screen to form a hologram near the transparent display sheet or the one-way mirror sheet.

A display device according to one or more embodiments may be provided with: a light guide plate that guides incident light and emits the light from a light exit surface; a half mirror disposed on the light-exit-surface side of the light guide plate; and a mirror disposed on the side opposite to the light exit surface of the light guide plate. The light guide plate may form an image accompanied by a change that is made in a direction from the half mirror toward the mirror in a space different from the light exit surface.

A cluster according to an embodiment of the disclosure includes a display and a spatial image panel. The display is installed in the vehicle to output predetermined information as a 2D image. The spatial image panel is configured to output a 3D image in a predetermined space in front. The spatial image panel includes a first lens array, a second lens array, and a refractive medium. The first lens array is disposed adjacent to the display and includes a plurality of first lenses arranged on the same plane. The second lens array is disposed in parallel with the first array so that the first lenses and second lenses overlap each other. The refractive medium is disposed between the first lens array and the second lens array.

A display device includes a display capable of displaying an image, a beam-splitter that reflects light from the display, a retro-reflective member that reflects the light from the beam-splitter in the same direction as incident light, a first variable unit that varies an inclination angle of the display, and a second variable unit that varies an inclination angle of the beam-splitter, and prevents the image of the display from entering an aerial image.

One form of a display device of the present disclosure includes a first optical structure and a second optical structure stacked on the first optical structure. The first optical structure includes a light source, a light guide layer, a reflection layer, and a half mirror, and a light diffusion surface for generating a design of a multiple image that is formed on a bottom portion of the light guide layer. The second optical structure includes a light source, a light guide layer, a retroreflective layer, and a half mirror, and a light diffusion surface for generating a design of the aerial image is formed on a bottom portion of the light guide layer. The aerial image and the multiple image are simultaneously observed from the viewpoint of the user, and a sense of depth or a stereoscopic effect can be imparted to the aerial image.

One form of a display device of the present disclosure includes a first optical structure and a second optical structure stacked on the first optical structure. The first optical structure includes a light source, a light guide layer, a reflection layer, and a half mirror, and a light diffusion surface for generating a design of a multiple image that is formed on a bottom portion of the light guide layer. The second optical structure includes a light source, a light guide layer, a retroreflective layer, and a half mirror, and a light diffusion surface for generating a design of the aerial image is formed on a bottom portion of the light guide layer. The aerial image and the multiple image are simultaneously observed from the viewpoint of the user, and a sense of depth or a stereoscopic effect can be imparted to the aerial image.

Provided in the present application is a holographic display system, comprising an on-site holographic display system, a transmissive geometric holographic display system, a geometric holographic display system with folded optical path, and a reflective geometric holographic display system. A display element capable of directly displaying screens provided with depth of field information is used to project a diverging 3D image in the air without the aid of another reference light source. The image is converted by a projection screen of an equivalent negative refractive index flat lens to then obtain an observable 3D image suspended in the air, which reduces costs. At the same time, the 3D image may be displayed in front of or behind the projection screen, the display space is infinite, and in a very small device space, a super large screen and super deep depth of field may also be displayed.

Provided in the present application is a holographic display system, comprising an on-site holographic display system, a transmissive geometric holographic display system, a geometric holographic display system with folded optical path, and a reflective geometric holographic display system. A display element capable of directly displaying screens provided with depth of field information is used to project a diverging 3D image in the air without the aid of another reference light source. The image is converted by a projection screen of an equivalent negative refractive index flat lens to then obtain an observable 3D image suspended in the air, which reduces costs. At the same time, the 3D image may be displayed in front of or behind the projection screen, the display space is infinite, and in a very small device space, a super large screen and super deep depth of field may also be displayed.