Provided are an optical biaxially stretched plastic film, a polarizing plate, and an image display device that can suppress blackouts when viewed with polarized sunglasses, polarized goggles or the like without increasing the in-plane phase difference. In addition, a method for selecting an optical biaxially stretched plastic film is provided.

The optical biaxially stretched plastic film has a region satisfying condition 1 and condition 2 below:

<Condition 1> the difference between a luminance obtained in a specific measurement 1 and a luminance obtained in a specific measurement 2 (L1.n−L2.n) is calculated at each of 100 measurement points, and the “luminance difference variation 3σ” calculated from the luminance differences at the 100 measurement points is 100 or more; and
<Condition 2> the in-plane phase difference (Re) is 2500 nm or less.

A privacy display comprises a spatial light modulator and a compensated switchable liquid crystal retarder arranged between first and second polarisers arranged in series with the spatial light modulator. In a privacy mode of operation, on-axis light from the spatial light modulator is directed without loss, whereas off-axis light has reduced luminance. The visibility of the display to off-axis snoopers is reduced by means of luminance reduction over a wide polar field. In a wide angle mode of operation, the switchable liquid crystal retardance is adjusted so that off-axis luminance is substantially unmodified.

A wave plate 1 according to an embodiment includes a first birefringent substrate 10 including a first main surface and an optical axis 13 in a first direction; a second birefringent substrate 20 disposed over the first birefringent substrate 10 and including a second main surface and an optical axis 23 in a second direction; and a third birefringent substrate 30 disposed over the second birefringent substrate 20 and including a third main surface and an optical axis 33 in a third direction. The first birefringent substrate 10 and the second birefringent substrate 20 are made of the same kind of birefringent material. The first main surface, the second main surface, and the third main surface are disposed in parallel to one another. The first direction and the second direction are parallel to the first main surface and the second main surface.

An optical element includes, sequentially from a viewing surface side toward a back surface side: a viewing-surface-side polarizer; a retarder; and a back-surface-side polarizer, a transmission axis of the viewing-surface-side polarizer and a transmission axis of the back-surface-side polarizer being parallel to each other, the optical element having an average angle θ between an angle θ1 and an angle θ2 of greater than 0° and smaller than 90°, wherein the angle θ1 represents an angle formed by an optical axis of the retarder on a surface close to the back surface with the surface close to the back surface; and the angle θ2 represents an angle formed by an optical axis of the retarder on a surface close to the viewing surface with the surface close to the viewing surface.

A privacy display comprises a spatial light modulator and a compensated switchable liquid crystal retarder arranged between first and second polarisers arranged in series with the spatial light modulator. In a privacy mode of operation, on-axis light from the spatial light modulator is directed without loss, whereas off-axis light has reduced luminance. The visibility of the display to off-axis snoopers is reduced by means of luminance reduction over a wide polar field. In a wide angle mode of operation, the switchable liquid crystal retardance is adjusted so that off-axis luminance is substantially unmodified.

Techniques are described for operating an optical system. In some embodiments, light associated with a world object is received at the optical system. Virtual image light is projected onto an eyepiece of the optical system. A portion of a system field of view of the optical system to be at least partially dimmed is determined based on information detected by the optical system. A plurality of spatially-resolved dimming values for the portion of the system field of view may be determined based on the detected information. The detected information may include light information, gaze information, and/or image information. A dimmer of the optical system may be adjusted to reduce an intensity of light associated with the world object in the portion of the system field of view according to the plurality of dimming values.

Provided is a liquid crystal display device capable of improving light utilization efficiency, without stacking a plurality of microlenses having a three-dimensional shape.

The liquid crystal display device includes a first substrate including a microlens corresponding to each pixel; a second substrate disposed to face the first substrate; and a liquid crystal material layer sandwiched between the first substrate and the second substrate, in which a first transparent material layer including a material having a first refractive index is formed in the first substrate, and a material having a second refractive index different from the first refractive index is disposed in a portion of the first transparent material layer corresponding to a region between adjacent pixels, and a second transparent material layer including a material having a third refractive index is formed in the second substrate, and a material having a fourth refractive index different from the third refractive index is disposed in a portion of the second transparent material layer corresponding to the region between adjacent pixels.

Provided is a viewing angle control system and an image display device which are capable of controlling the viewing angle of a display screen in a longitudinal direction and improving the visibility in a specific lateral direction. The viewing angle control system includes a polarizer, and a light absorption anisotropic layer, in which the polarizer has an in-plane absorption axis in a film, an angle θ between a transmittance central axis of the light absorption anisotropic layer and a normal line of the film is in a range of 0.1° to 45°, and an angle φ between a direction in which the transmittance central axis of the light absorption anisotropic layer is orthographically projected onto the film surface and the absorption axis of the polarizer is 0° or greater and less than 85°, greater than 95° and less than 265°, or greater than 275° and 360° or less.

A privacy display comprises a polarised output spatial light modulator, reflective polariser, plural polar control retarders and a polariser. In a privacy mode of operation, on-axis light from the spatial light modulator is directed without loss, whereas off-axis light has reduced luminance. Further, display reflectivity is reduced for on-axis reflections of ambient light, while reflectivity is increased for off-axis light. The visibility of the display to off-axis snoopers is reduced by means of luminance reduction and increased frontal reflectivity to ambient light. In a public mode of operation, the liquid crystal retardance is adjusted so that off-axis luminance and reflectivity are unmodified.

A touch sensor includes a substrate and first and second touch sensor electrode layers. The first touch sensor electrode layer is disposed on a first surface of the substrate, and includes a first pad formed on an opposing surface to a surface in contact with the substrate. The second touch sensor electrode layer is disposed on a second surface of the substrate, exposes at least a portion of the surface in contact with the substrate to an outside of the substrate, and includes a second pad formed on the portion exposed to the outside of the surface in contact with the substrate. The first pad and the second pad do not overlap in a stacking direction.