78results about How to "Avoid Contrast Loss" patented technology

A transmission screen is capable of preventing the reduction of contrast in images due to external light such as emitted by internal lighting fixtures. The transmission screen includes a Fresnel lens sheet having a front surface facing the viewer and provided with Fresnel lens elements, and a shading sheet 13 placed contiguously with the front surface of the Fresnel lens sheet. The shading sheet 13 is provided with shading elements 22 for absorbing external light fallen on the front surface of the shading sheet 13 and reflected in a total reflection mode by the back surface of the Fresnel lens sheet facing a projection light source toward the viewer. Preferably, the shading elements 22 transmit at least external light fallen on the shading sheet at an incident angle θ satisfying a condition expressed by: θ<24+0.018×F, where θ is incident angle of external light that falls on the shading sheet, and F is the focal length of the Fresnel lens elements in millimeter.

A color filter for use in a light-emitting display element which emits at least white light, the color filter including a circularly polarizing layer which includes a polarizing layer, the polarizing layer having an orientation layer and a liquid crystal compound layer, wherein the circularly polarizing layer is formed only in an optical path of the white light.

The invention discloses a liquid crystal display apparatus. A color-resistance layer, a photo-resistance spacer and a TFT layer are all arranged on a second base plate of a liquid crystal panel, so offset amount between layers of the second base plate can be reduced and high para-position precision can be achieved; a backlight module set is arranged on one side close to a first base plate of the liquid crystal panel and the second base plate is in a top-grid structure, so when a light source of the backlight module set enters from the first base plate side to the liquid crystal panel, a grid can cover a channel region of a polycrystalline silicon layer and great improving effect can be achieved for leak current of the second base plate; besides, a light-shielding metal layer of the side bottom layer of the second base plate is made of black metal; when external light enters from the second base plate side, with the light-shielding layer on the bottommost layer, a problem of contrast ratio decrease of the panel due to metal reflection by the incidence of light from the second base plate can be solved; and the liquid crystal display apparatus is simply structured and black matrix manufacturing can be avoided compared with the prior art.

A liquid crystal display-element which has the high speed response and the high contrast and a display device employing the same are provided. In a display device employing a reflection type liquid crystal light valve, a retardation of a retardation plate which is provided between a polarizing element such as a polarizing beam splitter and the reflection type liquid crystal light valve is generally made ¼ of the wavelength of the incident light, and an optical axis (a slow axis or a fast axis) of the retardation plate and the polarizing direction of the incident polarized light are shifted from each other by slightly larger than 0 degree in order to arrange such optical elements.

A light diffusing sheet of a structure in which a light diffusing layer is formed on at least one surface of a transparent film, the light diffusing layer including a resin coat layer having a minute unevenness shape and a low refractive index layer having a refractive index lower than that of the resin coat layer on the surface having a minute unevenness shape thereof, whereby the sheet can retain antiglare property, shows almost no white blurring to be recognized due to surface scattering, exhibits almost no birefringence, and is excellent in adherence and durability even when applied to a high definition LCD.

In an IPS type liquid crystal display device, a light shielding film, a red color filter, an overcoat film, and an alignment film are formed in this order on a counter substrate. However, the alignment film is not formed in a seal portion. When the alignment film is subjected to photo-alignment with ultraviolet radiation, a portion of the overcoat film not covered with the alignment film is degraded by ultraviolet radiation. In order to prevent moisture penetrating from the degraded overcoat film from reaching the light shielding film to thereby alter the light shielding film and from causing the peeling of the light shielding film, the red color filter is disposed below the overcoat film to block the moisture.

A photoelectric encoder that has a lens optical system including a lens inserted between a main scale and a light receiving element. In the photoelectric encoder, three planes extended from a surface of the main scale, a principal plane of the lens, and an image plane of the light receiving element are disposed so as to intersect at a single point and satisfy the Scheimpflug rule. Focus can thereby be obtained over the entire image plane, so that a reduction in contrast is prevented, even if the optical axis is inclined to make an optical system smaller.