Abstract: To provide a display device having a high contrast ratio by a simple and easy method and to manufacture a high-performance display device at low cost, in a display device having a display element between a pair of light-transmitting substrates, layers each including a polarizer having different wavelength distribution of extinction coefficient from each other with respect to the absorption axes are stacked and provided on an outer side of the light-transmitting substrates. Further, a retardation plate may be provided between the stacked polarizers.

Abstract: A display device having an electroluminescence element with an improved contrast ratio is provided. Stacked polarizing plates are provided on the outer side of substrates of a display device which includes a first light-transmitting substrate and a second light-transmitting substrate arranged to face each other and an electroluminescence element interposed therebetween that emits light to both the first light-transmitting substrate side and the second light-transmitting substrate side. The polarizing plates facing each other are arranged in a crossed nicol state. Furthermore, among a plurality of polarizing plates arranged to face each other, a plurality of polarizing plates which are stacked on one side or the other side of the light-transmitting substrates are arranged in a parallel nicol state. As a result, a display device with a high contrast ratio can be provided.

Abstract: A display device with a higher contrast ratio is provided. The display device is provided with stacked polarizing plates arranged displaced from a parallel nicol state. Moreover, in the display device, at least one of a pair of stacked polarizing plates is displaced from a parallel state. The pair of stacked polarizing plates is arranged in a cross nicol state. A retardation plate may be provided between the polarizing plate and the substrate. As a result, the contrast ratio can be increased.

Abstract: An object of the invention is to provide a display device having a high contrast ratio by a simple and easy method. Another object of the invention is to manufacture such a high-performance display device at low cost. In a display device having a display element between a pair of light-transmissive substrates, polarizing plates each having an extinction coefficient of an absorption axis which is different from that of an absorption axis of another polarizing plate are stacked to be provided. At that time, the stacked polarizing plates are arranged so as to be in a parallel nicol state. A wave plate and a retardation film may be provided between the stacked polarizing plates and the substrates.

Abstract: A problem exists in that black luminance in a liquid crystal display device when seen in a dark place is high compared to black luminance of a light emitting element in a non-light-emitting state, so as a result, contrast ratio is low. There is a high demand for contrast ratio to be improved. Therefore, it is an object of the present invention to provide a liquid crystal display device with improved contrast ratio and a wide viewing angle. Retardation films and stacked polarizing plates are provided over light transmitting substrates which sandwich a display element. A film having liquid crystal with hybrid oriented liquid crystal, a film having liquid crystal with twisted orientation, uniaxial retardation films, or biaxially retardation films can be used as the retardation films. It is preferable that the stacked polarizing plates comprise two polarizing plates.

Abstract: It is an object to provide a display device having an electroluminescent element in which a contrast ratio is increased. In a display device having an electroluminescent element between a pair of light transmitting substrates, a circularly polarizing plate having stacked polarizing plates arranged on outer sides thereof is provided. At this time, opposed polarizing plates are arranged to be in a crossed nicol state or in a parallel nicol state. As a result, a display device with a high contrast ratio can be provided.

Abstract: The invention provides a display device of which a contrast ratio is enhanced. By providing stacked polarizing plates so as to be in a cross nicol state, a contrast ratio of a display device can be enhanced. The stacked polarizing plates are stacked outside a light-transmissive insulating substrate in a parallel nicol state. When the number of polarizing plates is four or five in total, a contrast ratio becomes the highest.