Abstract:
An electronic device display may have an organic light-emitting diode layer that emits light to form images for a user. Reflective structures such as metal signal lines may be present in the organic light-emitting diode layer. Ambient light reflections from the metal signal lines may be suppressed using a circular polarizer on the organic light-emitting diode layer. To increase light emission efficiency from the organic light-emitting diode display layer under low ambient light conditions in which ambient light reflections are not significant, the polarization efficiency of the circular polarizer may be reduced. Control circuitry may make measurements of ambient light intensity using an ambient light sensor and can control the polarization efficiency of the circular polarizer accordingly by applying adjustable amounts of light or electric field. Polarization efficiency may also be adjusted using a photosensitive polarizer material that responds directly to changes in ambient light level.
Abstract:
A display may have a first stage such as a color liquid crystal display stage and a second stage such as a monochromatic liquid crystal display stage that are coupled in tandem so that light from a backlight passes through both stages. The pixel pitch of the second stage may be greater than the pixel pitch of the first stage to ease alignment tolerances and reduce image processing complexity. The first stage may be provided with straight black masking strips, whereas the second stage may be provided with angled zigzagging black masking strips. The angle of the zigzagging black masking strips and the ratio of the pixel pitch of the second stage to that of the first stage may be selected to maximize optical transmittance while minimizing Moire effects.
Abstract:
A display may include a color filter glass layer and a thin-film transistor glass layer that are attached with sealant. The thin-film transistor glass layer may have a recess in an inactive area of the display that accommodates a camera. The display layers may be provided with an opening that overlaps the recess. The recess may be a hole or a notch. The display may include circuitry and metal structures in the inactive area that are isolated from the recess with sealant. The sealant may have intersection points to isolate internal components from external contaminants and prevent reliability issues in the display. The display may be formed by cutting a motherglass layer into an individual display panel. The motherglass layer may include display layers attached with sealant. Cutting the mother glass layer may include cutting the sealant.
Abstract:
A display may have a first stage such as a color liquid crystal display stage and a second stage such as a monochromatic liquid crystal display stage that are coupled in tandem so that light from a backlight passes through both stages. The pixel pitch of the second stage may be greater than the pixel pitch of the first stage to ease alignment tolerances and reduce image processing complexity. The first stage may be provided with straight black masking strips, whereas the second stage may be provided with angled zigzagging black masking strips. The angle of the zigzagging black masking strips and the ratio of the pixel pitch of the second stage to that of the first stage may be selected to maximize optical transmittance while minimizing Moire effects.
Abstract:
An electronic device may have a display such as a liquid crystal display. A color filter layer may be formed on a display layer such as a transparent substrate layer. The color filter layer may include an array of color filter elements on a central portion of a surface of the transparent substrate layer. The color filter layer may include a peripheral color filter of a single color that at least partially surrounds the color filter elements on the central portion of the inner surface. In an inactive portion of the display, an opaque masking material may be formed over the peripheral color filter. In an active portion of the display the opaque masking material may form a grid that covers interfaces between adjacent color filter elements. The peripheral color filter may completely cover the surface of the substrate in the entire inactive portion of the display.
Abstract:
A display may have a color filter layer and a thin-film transistor layer. A layer of liquid crystal material may be located between the color filter layer and the thin-film transistor layer. Column spacers may be formed on the color filter layer to maintain a desired gap between the color filter and thin-film transistor layers. Support pads may be used to support the column spacers. Different column spacers may be located at different portions of the support pads to allow the support pad size to be reduced while ensuring adequate support. Lateral movement blocking structures such as circular rings may be used to prevent column spacer lateral movement. Subspacers located over pads may be used to create friction that retards lateral movement. Lateral movement may also be retarded by receiving column spacers in trenches or other recesses formed on a thin-film transistor layer.
Abstract:
Displays such as liquid crystal displays may be provided with transparent substrates that minimize light leakage from the display. The transparent substrates may include a thin-film transistor substrate having thin-film transistors formed on a surface of the thin-film transistor substrate and a color filter substrate having color filter elements formed on a surface of the color filter substrate. The thin-film transistor substrate may be formed from a material having a relatively low photo-elastic constant. The color filter substrate may be formed from a material having a relatively low photo-elastic constant. Reduced birefringence effects in the thin-film transistor substrate and the color filter substrate may help minimize light leakage from the display when some or all of the display experiences internal or external stresses.