A crystal for flow cytometry with dual laser beams is disclosed. The crystal is a birefringent crystal comprising a material composition including a quartz mineral having a face side including a face angle of ninety degrees plus or minus one tenth of a degree; a wedge side that is substantially perpendicular to the face side, wherein the wedge side includes a wedge angle of two degrees plus or minus one tenth of a degree; and a major side that is substantially perpendicular to the face side and the wedge side. The major side includes a thickness of one and one-half millimeter plus or minus one tenth of a millimeter. A polarized light beam entering the birefringent crystal at an incident angle is separated into an ordinary light beam and an extraordinary light beam.

A speckle elimination apparatus, a laser light source and a laser projection system, the speckle elimination apparatus comprising a wave plate (100) and a transmission plate (200) respectively arranged on a laser beam light path, the wave plate (100) and the transmission plate (200) having similar refractive indices and closely arranged adjacent sides, the wave plate (100) being arranged so that an incident surface allows a portion of an incident laser beam to pass through, the transmission plate (200) being arranged so that an incident surface allows the remainder of the incident laser beam to pass through, the portion of the incident laser beam being 25%-75% of the incident laser beam. The speckle elimination apparatus eliminates the phenomenon of laser speckle, and prevents stray light from being produced during laser speckle elimination.

A polarizing plate for IPS mode and an optical display apparatus including the same are provided. A polarizing plate includes: a polarizer; a first protective layer on an upper surface of the polarizer; and a second protective layer on a lower surface of the polarizer, wherein, assuming an axis of the polarizer having a high index of refraction in an in-plane direction of the polarizer is a reference axis (0°), an angle of an axis of the first protective layer having a low index of refraction in the in-plane direction thereof is in a range of about −5° to +5°, the first protective layer has an in-plane retardation Re of about 5,000 nm or more at a wavelength of 550 nm, the second protective layer includes a positive C plate layer, and the second protective layer satisfies at least one of Relations 1 and 2.

A head-up display device including a display unit, a polarization beam-splitting module, and an optical module is provided. The polarization beam-splitting module receives a first image beam and a second image beam from the display unit, and transmits the first image beam and the second image beam to the optical module. The first image beam and the second image beam are respectively reflected by the optical module to an outside of the head-up display device, and then transmitted to a target element, to form a first virtual image and a second virtual image. By the polarization beam-splitting module, an optical path length of the first image beam from the display unit to a position of the first virtual image formed by itself is longer than an optical path length of the second image beam from the display unit to a position of the second virtual image formed by itself.

A focusing device includes a substrate and a plurality of scatterers provided at both sides of the substrate. The scatterers on the both sides of the focusing device may correct geometric aberration, and thus, a field of view (FOV) of the focusing device may be widened.

The present invention relates generally to a head-mounted projection display, and more particularly, but not exclusively to a polarized head-mounted projection display including a light engine and a compact, high-performance projection lens for use with reflective microdisplays.

Optical film stacks are described. More particularly, optical film stacks including a half-wave retardation layer are described. Achromatic half-wave retardation layers, including achromatic half-wave layers formed from a quarter-wave and a three-quarters-wave retardation layer, are described. Film stacks including reflective polarizers tuned to reduce wavelength dispersion of the half-wave retardation layer are also described.

A polymer liquid crystal compound with which a light absorption anisotropic film having a high alignment degree can be formed, a liquid crystalline composition, a light absorption anisotropic film which is formed of the liquid crystalline composition, a laminate, and an image display device. The liquid crystalline composition includes a polymer liquid crystal compound which contains a repeating unit represented by Formula (1) and a dichroic substance. In Formula (1), a difference between a log P value of P1, L1, and SP1 and a log P value of M1 is 4 or greater. In Formula (1), P1 represents a main chain of the repeating unit, L1 represents a single bond or a divalent linking group, SP1 represents a spacer group, M1 represents a mesogenic group, and T1 represents a terminal group. ##STR00001##

Examples include a device including a nanovoided polymer element having a first surface and a second surface, a first plurality of electrodes disposed on the first surface, a second plurality of electrodes disposed on the second surface, and a control circuit configured to apply an electrical potential between one or more of the first plurality of electrodes and one or more of the second plurality of electrodes to induce a physical deformation of the nanovoided polymer element.

A switchable privacy display comprises a spatial light modulator (SLM), a first switchable liquid crystal (LC) retarder and first passive retarder arranged between a first pair of polarisers and a second switchable LC retarder and second passive retarder arranged between a second pair of polarisers. Each switchable LC retarder comprises a homeotropic alignment layer and a homogeneous alignment layer. In privacy mode, on-axis light from the SLM is directed without loss, whereas off-axis light has reduced luminance to reduce the visibility of the display to off-axis snoopers. The display may achieve privacy operation in landscape and portrait orientations. Further, display reflectivity may be reduced for on-axis reflections of ambient light, while reflectivity may be increased for off-axis light to achieve increased visual security. In public mode, the liquid crystal retardance is adjusted so that off-axis luminance and reflectivity are unmodified. The display may be switched between day-time and night-time operation.