A projection screen control method of one embodiment of the present disclosure includes irradiating a display member with first control light, and irradiating the display member with second control light, in which the irradiating the display member with the first control light and the irradiating the display member with the second control light are performed in sequence. The display member has a visible light transmittance or a visible light reflectance that varies depending on light, and contains a photochromic material, and the first control light and the second control light have different light intensities.

A writing device includes a liquid crystal layer including reflective cholesteric liquid crystal material. There are electrically conductive layers between which the liquid crystal layer is disposed. At least one of the electrically conductive layers includes at least two conductive sections. There is a front substrate that is flexible and a back substrate between which the electrically conductive layers and the liquid crystal layer are disposed. Neither the front substrate nor the back substrate includes separated sections. Application of pressure to the front substrate changes a reflectivity of a portion of the cholesteric liquid crystal material to form an image. In one aspect, there is electronic erase circuitry including at least one actuator that independently applies an erase voltage waveform to each of at least two of the conductive sections. In another aspect the electronic erase circuitry includes at least one actuator that independently applies an erase voltage waveform to each of the conductive sections, and that applies erase voltage waveforms to at least two of the conductive sections in combination.

An anti-tamper device combining a RFID component and an article surveillance or security component with a visual indicator. The article surveillance or security component is operatively coupled to a display so that an interruption of the RFID component is visibly indicated by the display. The visual indicator moves between a first state indicating a lack of tampering, and a second state indicating tampering without the need for a battery or external power source.

A freeform varifocal optical assembly includes at least three optical modules including a first plurality of optical elements including Pancharatnam-Berry phase (PBP) lenses, polarization sensitive hologram (PSH) lenses, metamaterials, or combinations thereof. The plurality of optical elements of each optical module include a property associated with a Zernike polynomial. Each of the first and the three optical modules are configurable between a plurality of optical powers. The freeform varifocal optical assembly is configurable to output a predetermined wavefront in response to an input wavefront.

Embodiments of the present disclosure relate to a photomask. The photomask may include: a substrate; and one or more pixel units formed over the substrate. Each pixel unit may include: at least one polymer crystal element configured to interact with extreme ultraviolet (EUV) light based on an orientation of the polymer crystal element; and a plurality of electrodes configured to control the orientation of the polymer crystal element by applying voltage across the polymer crystal element. Each pixel unit is controlled by the respective plurality of electrodes independently, and the one or more pixel units generate a pattern for lithography upon exposure to the EUV light.

A display device including a display area and a non-display area is provided. The display area includes a display panel, a switch unit and a first reflective film. The non-display area includes a second reflective film. The switch unit is disposed on the display panel. The first reflective film is disposed between the display panel and the switch unit. When the display device is set in a pattern mode, the display panel does not emit image light. For the pattern mode, the reflectivity in the display area is approximately equal to the reflectivity in the non-display area for ambient light.

The present disclosure provides a transparent screen including two main surfaces, and out of light of which a wavelength incident on one main surface out of the two main surfaces is 532 nm, a half width of a peak observed in a distribution indicating strength with respect to a diffraction angle of a primary diffraction light emitted from the other main surface out of the two main surfaces is 2 degrees or greater.

A display apparatus includes a light source emitting light; a light guide plate having a first surface and a second surface, and spreading light emitted from the light source therein to emit light through the first surface; and a local dimming unit configured to pass or scatter light emitted through the second surface of the light guide plate according to a position. The local dimming unit may include: an electro-optical layer configured to which optical properties change according to an electric field; and a plurality of electrodes positioned on the same plane to generate the electric field.

A method for producing a cholesteric liquid crystal layer is a method that can produce a cholesteric liquid crystal layer whose reflection surface is not parallel to a substrate surface by a simple method. The method includes: a step 1 of forming a composition layer satisfying a condition 1, a condition 2, or a condition 3 on a substrate, using a liquid crystal composition including a liquid crystal compound; and a step 2 of subjecting the composition layer to a treatment for cholesterically aligning the liquid crystal compound in the composition layer to form a cholesteric liquid crystal layer.

An optical element includes a cholesteric liquid crystal layer obtained by cholesterically aligning a liquid crystal compound, in which the cholesteric liquid crystal layer has a region where a refractive index nx in a slow axis direction and a refractive index ny in a fast axis direction in a plane satisfy nx>ny, a helical axis of the cholesteric alignment is parallel to a thickness direction of the cholesteric liquid crystal layer, and a helical pitch in the cholesteric alignment gradually changes in the thickness direction of the cholesteric liquid crystal layer.