A light-emitting device includes a first electrode, a second electrode and a light-emitting layer arranged between the first electrode and the second electrode. The light-emitting layer includes a thermally activated delayed fluorescence (TADF) material, and the TADF material includes a donor, an acceptor, and a linking group connected between the donor and the acceptor. The donor includes a donor base unit, and a substituent connected to the donor base unit, and atoms in the donor base unit are located in a first plane. The acceptor includes an acceptor base unit, and a substituent connected to the acceptor base unit, and atoms in the acceptor base unit are located in a second plane. The linking group includes a linking base unit, and a substituent connected to the linking base unit, and atoms in the linking base unit are located in a third plane.

A light-emitting device includes a first electrode, a second electrode and a light-emitting layer arranged between the first electrode and the second electrode. The light-emitting layer includes a thermally activated delayed fluorescence (TADF) material, and the TADF material includes a donor, an acceptor, and a linking group connected between the donor and the acceptor. The donor includes a donor base unit, and a substituent connected to the donor base unit, and atoms in the donor base unit are located in a first plane. The acceptor includes an acceptor base unit, and a substituent connected to the acceptor base unit, and atoms in the acceptor base unit are located in a second plane. The linking group includes a linking base unit, and a substituent connected to the linking base unit, and atoms in the linking base unit are located in a third plane.

Embodiments of the disclosed subject matter may provide a wearable device that includes an organic light emitting diode (OLED) light source to output light. At least one emissive layer of the OLED light source of the wearable device may have a plurality of segments that are independently controllable to output the light at a duty cycle of less than 100%. The OLED light source of the wearable device may be encapsulated.

A display panel includes a thin film transistor layer (4), a grating layer (3), a transparent anode layer (2), an emission layer (1), and a colored layer (6) opposite the emission layer (1). The colored layer (6) may include a plurality of color filters. The grating layer (3) may be between the thin film transistor layer (4) and the transparent anode layer (2). The grating layer (3) may include a plurality of blazed gratings corresponding to the plurality of color filters, respectively.

The present disclosure relates to a display panel. The display panel includes a display substrate, an opposite substrate, and a first adhesive layer and light guide layer located between the display substrate and the opposite substrate and stacked on each other. The first adhesive layer includes a photo-cured layer formed by curing a photocurable material layer. And the light guide layer is used to direct light to the photocurable material layer during the curing to form the cured layer.

A display device includes a display panel that emits light from a plurality of pixels arrayed at predetermined pixel array pitches and an optical film, placed over the display panel so as to allow passage of light from the plurality of pixels, that includes first and second optical functional parts differing in optical performance from each other. The first and second optical functional parts are arrayed at predetermined functional part array pitches. Assuming that p (μm) denotes the pixel array pitches, that q (μm) denotes the functional part array pitches, and that d (μm) denotes a distance in a face-to-face direction between surfaces of the pixels that face the optical film and a surface of the optical film that faces the pixels, q≤0.5p and tan(asin(0.7/q))<p/d hold.

A display device includes a display panel that emits light from a plurality of pixels arrayed at predetermined pixel array pitches and an optical film, placed over the display panel so as to allow passage of light from the plurality of pixels, that includes first and second optical functional parts differing in optical performance from each other. The first and second optical functional parts are arrayed at predetermined functional part array pitches. Assuming that p (μm) denotes the pixel array pitches, that q (μm) denotes the functional part array pitches, and that d (μm) denotes a distance in a face-to-face direction between surfaces of the pixels that face the optical film and a surface of the optical film that faces the pixels, q≤0.5p and tan(asin(0.7/q))<p/d hold.

Provided are organometallic compounds that includes a ligand L.sub.A of

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Also provided are formulations comprising these organometallic compounds. Further provided are OLEDs and related consumer products that utilize these organometallic compounds.

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.

An organic light emitting display device includes a substrate, a lower electrode, a light emitting layer, an upper electrode, and a light guide structure. The substrate includes a sub-pixel region and a transparent region. The lower electrode is disposed in the sub-pixel region on the substrate. The light emitting layer is disposed on the lower electrode, and includes an organic emission layer. The upper electrode is disposed on the light emitting layer. The light guide structure is disposed on the upper electrode, and partially overlaps the organic emission layer that is located at the sub-pixel region and the substrate that is located at the transparent region in a plan view.