JP2007180024A - Display - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a display having an electroluminescent element with an increased contrast ratio. <P>SOLUTION: In a display having the electroluminescent element between a pair of light transmitting substrates, a circularly polarizing plate having stacked polarizing plates arranged on the outer sides thereof is provided. The opposed polarizing plates are arranged to be in a crossed nicol state or in a parallel nicol state. As a result, the display with the high contrast ratio can be provided. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

The present invention relates to a configuration of a display device for increasing a contrast ratio.

Development of a so-called flat panel display, which is much thinner and lighter than conventional cathode-ray tubes, is being developed. Flat panel displays are competing with liquid crystal display devices with liquid crystal elements as display elements, display devices with self-luminous elements, FED (field emission display) using electron sources, etc. Therefore, low power consumption and high contrast are required.

In a general liquid crystal display device, one polarizing plate is provided on each substrate, and the contrast ratio is maintained. As the contrast ratio increases, a clear black display can be performed, and a high display quality can be provided when an image is viewed in a dark room like a home theater.

For example, in order to increase the contrast ratio, a first polarizing plate is provided on the outside of the substrate on the viewing side of the liquid crystal cell, and a second polarizing plate is provided on the outside of the substrate opposite to the viewing side. A configuration in which a third polarizing plate is provided when the light from the auxiliary light source is polarized through the second polarizing plate and passes through the liquid crystal cell has been proposed (see Patent Document 1).

As a flat panel display similar to a liquid crystal display device, there is a display device having an electroluminescence element. The electroluminescence element is a self-luminous element, can eliminate the need for light irradiation means such as a backlight, and can reduce the thickness of the display device. Furthermore, a display device having an electroluminescence element has advantages such as a faster response speed and less viewing angle dependency than a liquid crystal display device.

A configuration in which a polarizing plate and a circularly polarizing plate are provided is also proposed for a display device having such an electroluminescence element (see Patent Documents 2 and 3).

In addition, as a structure of a display device having an electroluminescence element, light emitted from a light emitting element sandwiched between light-transmitting substrates can be observed as light on the anode substrate side and light on the cathode substrate side. (See Patent Document 4).
International Publication No. 00/34821 Japanese Patent No. 2761453 Japanese Patent No. 3174367 Japanese Patent Laid-Open No. 10-255976

However, the demand for increasing the contrast ratio is not limited to liquid crystal display devices, but is also required for display devices having electroluminescent elements.

In view of the above problems, the present invention is characterized in that a circularly polarizing plate having a plurality of polarizing plates is provided on a light-transmitting substrate disposed so as to face each other. The plurality of polarizing plates can be a polarizing plate having a laminated structure. In addition, since the circularly polarizing plate has a configuration including a polarizing plate and a retardation plate, the present invention includes a retardation plate, a plurality of polarizing plates, and a translucent substrate disposed so as to face each other. Are arranged in order.

Opposing polarizing plates are arranged so as to be crossed Nicols or parallel Nicols. Crossed Nicol is an arrangement in which the transmission axes of the polarizing plates are shifted by 90 °. Parallel Nicol is arranged such that the deviation between the transmission axes of the polarizing plates is 0 °. An absorption axis is provided so as to be orthogonal to the transmission axis of the polarizing plate, and crossed Nicols and parallel Nicols are defined in the same manner even when the absorption axis is used. The laminated polarizing plates are arranged so as to be parallel Nicols.

The polarizing plate provided on one substrate side and the retardation plate are arranged so as to be shifted by 45 °. Specifically, when the transmission axis of the polarizing plate is 90 °, the retardation plate is arranged so that the slow axis is 45 ° or 135 °.

The first light-transmitting substrate and the second light-transmitting substrate are disposed so as to face each other, and are provided between the opposed substrates. A light-emitting element that emits light in both directions, a first circularly polarizing plate having a stacked first linearly polarizing plate disposed outside the first light-transmitting substrate, and an outside of the second light-transmitting substrate And a second circularly polarizing plate having a stacked second linearly polarizing plate, which is disposed in the display device.

The first light-transmitting substrate and the second light-transmitting substrate are disposed so as to face each other, and are provided between the opposed substrates. A light-emitting element that emits light in both directions, a first circularly polarizing plate having a stacked first linearly polarizing plate disposed outside the first light-transmitting substrate, and an outside of the second light-transmitting substrate And a second circularly polarizing plate having a laminated second linearly polarizing plate, and arranged so that the transmission axes of the laminated first linearly polarizing plates are parallel Nicols. The transmission axes of the laminated second linearly polarizing plates are arranged in parallel Nicols, the transmission axis of the laminated first linearly polarizing plate, and the transmission axis of the laminated second linearly polarizing plate. Is a display device that is arranged in parallel Nicols.

The first light-transmitting substrate and the second light-transmitting substrate are disposed so as to face each other, and are provided between the opposed substrates. A light emitting element that emits light in both directions, a stacked first linear polarizing plate disposed outside the first light transmissive substrate, and a stacked layer disposed outside the second light transmissive substrate A first retardation plate provided between the second linearly polarizing plate, the first translucent substrate, the first linearly polarizing plate, the second translucent substrate, and the second A second retardation plate provided between the linearly polarizing plates, and arranged so that the transmission axes of the laminated first linearly polarizing plates are parallel Nicols, and are laminated The transmission axes of the linear polarizing plates are arranged in parallel Nicols, and the transmission axes of the stacked first linear polarizing plates and the transmission of the stacked second linear polarizing plates. The second linearly polarizing plate is arranged so that the axis is parallel Nicol, the slow axis of the first retardation plate is 45 ° with respect to the transmission axis of the first linearly polarizing plate. The second retardation plate is arranged so that the slow axis of the second retardation plate is 45 ° with respect to the transmission axis.

The first light-transmitting substrate and the second light-transmitting substrate are disposed so as to face each other, and are provided between the opposed substrates. A light emitting element that emits light in both directions, a stacked first linearly polarizing plate disposed outside the first light-transmitting substrate, and a second light-transmitting substrate disposed outside the second light-transmitting substrate A first retardation plate, a second translucent substrate, and a second linear polarizing plate provided between the linear polarizing plate, the first translucent substrate, and the first linear polarizing plate A first retardation plate laminated between the transmission lines of the first linearly polarizing plates stacked so as to be parallel Nicols. The transmission axis of the plate and the transmission axis of the second linearly polarizing plate are arranged so as to be parallel Nicols, and the slow phase of the first retardation plate with respect to the transmission axis of the first linearly polarizing plate Is disposed at an angle of 45 °, and the slow axis of the second retardation plate is at an angle of 45 ° with respect to the transmission axis of the second linearly polarizing plate. is there.

The first light-transmitting substrate and the second light-transmitting substrate are disposed so as to face each other, and are provided between the opposed substrates. A light-emitting element that emits light in both directions, a first circularly polarizing plate having a stacked first linearly polarizing plate disposed outside the first light-transmitting substrate, and an outside of the second light-transmitting substrate And a second circularly polarizing plate having a laminated second linearly polarizing plate, and arranged so that the transmission axes of the laminated first linearly polarizing plates are parallel Nicols. The transmission axes of the laminated second linearly polarizing plates are arranged in parallel Nicols, the transmission axis of the laminated first linearly polarizing plate, and the transmission axis of the laminated second linearly polarizing plate. Is a display device that is arranged to be crossed Nicols.

The first light-transmitting substrate and the second light-transmitting substrate are disposed so as to face each other, and are provided between the opposed substrates. A light emitting element that emits light in both directions, a stacked first linear polarizing plate disposed outside the first light transmissive substrate, and a stacked layer disposed outside the second light transmissive substrate A first retardation plate provided between the second linearly polarizing plate, the first translucent substrate, the first linearly polarizing plate, the second translucent substrate, and the second A second retardation plate provided between the linearly polarizing plates, and arranged so that the transmission axes of the laminated first linearly polarizing plates are parallel Nicols, and are laminated The transmission axes of the linear polarizing plates are arranged in parallel Nicols, and the transmission axes of the stacked first linear polarizing plates and the transmission of the stacked second linear polarizing plates. The second linearly polarized light is disposed so as to be crossed Nicol and is 45 ° to the slow axis of the first retardation plate with respect to the transmission axis of the first linear polarizing plate. The display device is characterized in that the second retardation plate is disposed at 45 ° with respect to the transmission axis of the plate.

The first light-transmitting substrate and the second light-transmitting substrate are disposed so as to face each other, and are provided between the opposed substrates. A light emitting element that emits light in both directions, a stacked first linearly polarizing plate disposed outside the first light-transmitting substrate, and a second light-transmitting substrate disposed outside the second light-transmitting substrate A first retardation plate, a second translucent substrate, and a second linear polarizing plate provided between the linear polarizing plate, the first translucent substrate, and the first linear polarizing plate A first retardation plate laminated between the transmission lines of the first linearly polarizing plates stacked so as to be parallel Nicols. The transmission axis of the plate and the transmission axis of the second linear polarizing plate are arranged so as to be crossed Nicols, and the slow axis of the first retardation plate with respect to the transmission axis of the first linear polarizing plate Is arranged so as to be 45 °, and is arranged so as to be 45 ° with respect to the slow axis of the second retardation plate with respect to the transmission axis of the second linearly polarizing plate. It is.

In the present invention, the display element is a light emitting element. As a light emitting element, there are an element using electroluminescence (electroluminescence element), an element using plasma, and an element using field emission. An electroluminescence element can be distinguished from an organic EL element or an inorganic EL element depending on a material to be applied. A display device having such a light-emitting element is also referred to as a light-emitting device.

With a simple structure such as providing a plurality of polarizing plates, the contrast ratio of a display device having a light-emitting element can be increased.

Embodiments of the present invention will be described below with reference to the drawings. However, the present invention can be implemented in many different modes, and those skilled in the art can easily understand that the modes and details can be variously changed without departing from the spirit and scope of the present invention. Is done. Therefore, the present invention is not construed as being limited to the description of this embodiment mode. Note that in all the drawings for describing the embodiments, the same portions or portions having similar functions are denoted by the same reference numerals, and repetitive description thereof is omitted.

(Embodiment 1)
In this embodiment mode, the concept of the display device of the present invention will be described. In this embodiment mode, description is made using an electroluminescence element as a light-emitting element.

As shown in FIG. 1, a layer 100 having an electroluminescent element is sandwiched between a first light-transmitting substrate 101 and a second light-transmitting substrate 102 which are arranged so as to face each other. Light emitted from the electroluminescence element can emit light emitted from the first light-transmitting substrate 101 side and the second light-transmitting substrate 102 side (in the direction of the dotted arrow). As the light-transmitting substrate, for example, a glass substrate such as barium borosilicate glass or alumino borosilicate glass, a quartz substrate, or the like can be used. In addition, a substrate made of a plastic such as polyethylene-terephthalate (PET), polyethylene naphthalate (PEN), or polyethersulfone (PES), or a synthetic resin having flexibility such as acrylic can be used.

A phase difference plate and a stacked polarizing plate are provided outside the first light-transmitting substrate 101 and the second light-transmitting substrate 102, that is, on the side not in contact with the layer 100 having an electroluminescent element. The light is linearly polarized by the polarizing plate and circularly polarized by the retardation plate. That is, the laminated polarizing plate can be described as a laminated linearly polarizing plate. The laminated polarizing plate refers to a state in which two or more polarizing plates are laminated.

A retardation plate (A) 113, a first polarizing plate (A) 111, and a second polarizing plate (A) 112 are provided in this order on the outside of the first light-transmitting substrate 101. Thus, a retardation plate, in this case, a λ / 4 plate, and a laminated polarizing plate are combined and also referred to as a circularly polarizing plate having a laminated polarizing plate (linear polarizing plate). The transmission axis (A) of the first polarizing plate (A) 111 and the transmission axis (A) of the second polarizing plate (A) 112 are arranged in parallel. That is, the first polarizing plate (A) 111 and the second polarizing plate (A) 112, that is, the stacked polarizing plates (A) are arranged in parallel Nicols.
The slow axis (A) of the retardation plate (A) 113 is 45 with the transmission axis (A) of the first polarizing plate (A) 111 and the transmission axis (A) of the second polarizing plate (A) 112. ° Arranged so as to deviate.

FIG. 2A shows the deviation angle between the transmission axis (A) and the slow axis (A). The slow axis (A) forms 135 °, the transmission axis (A) forms 90 °, and these are shifted by 45 °.

In addition, a retardation plate (B) 123, a first polarizing plate (B) 121, and a second polarizing plate (B) 122 are provided in this order on the outer side of the second light transmitting substrate 102. In this way, the retardation plate and the laminated polarizing plates are combined and also referred to as a circularly polarizing plate having the laminated polarizing plates. The transmission axis (B) of the first polarizing plate (B) 121 and the transmission axis (B) of the second polarizing plate (B) 122 are arranged in parallel. That is, the first polarizing plate (B) 121 and the second polarizing plate (B) 122, that is, the stacked polarizing plates (B) are arranged in parallel Nicols. The slow axis (B) of the retardation plate (B) 123 is 45 with the transmission axis (B) of the first polarizing plate (B) 121 and the transmission axis (B) of the second polarizing plate (B) 122. It is arranged so that it is shifted.

FIG. 2B shows the deviation angle between the transmission axis (B) and the slow axis (B). The slow axis (B) forms 45 °, the transmission axis (B) forms 0 °, and these are shifted by 45 °. That is, the retardation plate (A) is arranged so that the slow axis of the retardation plate (A) is 45 °, that is, inclined by 45 ° with respect to the transmission axis of the laminated polarizing plate (A). The slow axis of the phase difference plate (B) is 45 ° with respect to the axis, that is, is arranged so as to be inclined by 45 °.

Then, the transmission axis (A) of the laminated polarizing plate (A) provided on the first light-transmitting substrate 101 and the laminated polarizing plate (provided on the second light-transmitting substrate 102). B) is perpendicular to the transmission axis (B). That is, the laminated polarizing plate (A) and the laminated polarizing plate (B), that is, the opposing polarizing plates are arranged so as to form a crossed Nicol.

In FIG. 2C, the transmission axis (A) and the slow axis (A) are indicated by solid lines, the transmission axis (B) and the slow axis (B) are indicated by dotted lines, and a state in which these are overlapped is shown. . FIG. 2C shows that the transmission axis (A) and the transmission axis (B) have a crossed Nicols state, and the slow axis (A) and the slow axis (B) have a crossed Nicols state.

These polarizing plates can be formed from a known material. For example, an adhesive surface, a TAC (triacetyl cellulose), a mixed layer of PVA (polyvinyl alcohol) and iodine, and a structure in which TAC are sequentially stacked are used from the substrate side. Can do. The degree of polarization can be controlled by a mixed layer of PVA (polyvinyl alcohol) and iodine. Moreover, a polarizing plate may be called a polarizing film from the shape.

Note that, due to the characteristics of the polarizing plate, there is a transmission axis in a direction orthogonal to the absorption axis. Therefore, even when the transmission axes are parallel to each other, it can be called parallel Nicol.

Further, due to the characteristics of the phase difference plate, there is a fast axis in a direction orthogonal to the slow axis. Therefore, the arrangement with the polarizing plate can be determined using not only the slow axis but also the fast axis. In the present embodiment, the transmission axis and the slow axis are arranged so as to be shifted by 45 °. In other words, the transmission axis and the fast axis are arranged so as to be shifted by 135 °.

In addition, in the circular polarizing plate, there is a circular polarizing plate with a wide band which can widen the wavelength range where the phase difference between the s wave and the p wave is 90 degrees by overlapping several retardation plates. Also, the slow axes of the retardation plates that are the same between the slow axis of each retardation plate arranged outside the first light transmitting substrate 101 and each retardation plate arranged outside the second light transmitting substrate 102 are The transmission axes of the polarizing plates arranged at 90 degrees and facing each other may be in a crossed Nicols arrangement.

By laminating so that the transmission axes of the laminated polarizing plates are parallel Nicols, light leakage in the absorption axis direction can be reduced. And it arrange | positions so that the polarizing plates which oppose may become cross Nicole. By providing a circularly polarizing plate having such a polarizing plate, light leakage can be reduced as compared with a circularly polarizing plate arranged so that single polarizing plates are crossed Nicols. For this reason, the contrast ratio of the display device can be increased.

(Embodiment 2)
In this embodiment mode, a concept of a display device in which the transmission axis (A) and the transmission axis (B) are in a parallel Nicol state, that is, opposite polarizing plates are in a parallel Nicol state, unlike the above embodiment mode, will be described.

As illustrated in FIG. 3, a layer 100 having an electroluminescence element is sandwiched between a first light-transmitting substrate 201 and a second light-transmitting substrate 202. Light from the electroluminescence element is emitted to the first light-transmissive substrate 201 side and the second light-transmissive substrate 202 side. A retardation plate (A) 213, a first polarizing plate (A) 211, and a second polarizing plate (A) 212 are provided in this order on the outside of the first light transmitting substrate 201. The transmission axis (A) of the first polarizing plate (A) 211 and the transmission axis (A) of the second polarizing plate (A) 212, that is, the stacked polarizing plates (A) are arranged in parallel Nicols. Is done. The slow axis (A) of the retardation plate (A) 213 is 45 with the transmission axis (A) of the first polarizing plate (A) 211 and the transmission axis (A) of the second polarizing plate (A) 212. It is arranged so that it is shifted.

FIG. 4A shows the deviation angle between the transmission axis (A) and the slow axis (A). The slow axis (A) is 45 °, the transmission axis (A) is 0 °, and they are shifted by 45 °.

In addition, a retardation plate (B) 223, a first polarizing plate (B) 221, and a second polarizing plate (B) 222 are sequentially provided on the outer side of the second light transmitting substrate 202. The first polarizing plate (B) 221 and the second polarizing plate (B) 222, that is, the stacked polarizing plates (B) are arranged in parallel Nicols. The slow axis (B) of the retardation plate (B) 223 is 45 with the transmission axis (B) of the first polarizing plate (B) 221 and the transmission axis (B) of the second polarizing plate (B) 222. ° Arranged so as to deviate.

FIG. 4B shows the deviation angle between the transmission axis (B) and the slow axis (B). The slow axis (B) forms 45 °, the transmission axis (B) forms 0 °, and these are shifted by 45 °. That is, the retardation plate (A) is arranged so that the slow axis of the retardation plate (A) is 45 °, that is, inclined by 45 ° with respect to the transmission axis of the first polarizing plate. The slow axis of the plate (B) is 45 °, that is, is arranged so as to be inclined by 45 °, and the transmission axis of the laminated polarizing plate (B) is 0 with respect to the transmission axis of the laminated polarizing plate (A). It is arranged so as to be at 0 °, that is, inclined at 0 °.

Unlike the above embodiment, the transmission axis (A) of the laminated polarizing plate (A) provided on the first light-transmitting substrate 201 and the second light-transmitting substrate 202 are provided. The transmission axis (B) of the laminated polarizing plate (B) is parallel to the polarizing plate (B). That is, the laminated polarizing plate (A) and the laminated polarizing plate (B), that is, the opposing polarizing plates are arranged so as to form parallel Nicols.

FIG. 4C shows a state where the transmission axis (A) and the slow axis (A) are overlapped with the transmission axis (B) and the slow axis (B), which are parallel Nicols. I understand that.

In addition, in the circular polarizing plate, there is a broadband circular polarizing plate that can widen the wavelength range where the phase difference between the s wave and the p wave is 90 degrees by overlapping several retardation plates. Also, the slow axes of the same phase difference plate between the slow axis of each retardation plate arranged outside the first light transmitting substrate 201 and each retardation plate arranged outside the second light transmitting substrate 202 are The transmission axes of the polarizing plates arranged in parallel and facing each other may be arranged in parallel Nicols.

By laminating so that the transmission axes of the laminated polarizing plates are parallel Nicols, light leakage in the absorption axis direction can be reduced. And the polarizing plates which oppose are arrange | positioned so that it may become parallel Nicols. By providing such a circularly polarizing plate, light leakage can be reduced as compared with a circularly polarizing plate arranged so that the polarizing plate single layers are parallel Nicols. For this reason, the contrast ratio of the display device can be increased.

In the case where a circularly polarizing plate having a broad band is used, black display may be performed even when the transmission axis of the polarizing plate and the slow axis of the retardation plate are different from those in the first and second embodiments. Even in this case, the contrast ratio can be increased if the transmission axes of the polarizing plates to be laminated are arranged in parallel Nicols as in the first and second embodiments.

(Embodiment 3)
In this embodiment, the concept of a display device using a circularly polarizing plate having stacked polarizing plates and a circularly polarizing plate having one polarizing plate will be described.

As shown in the first embodiment, opposing polarizing plates are arranged in crossed Nicols. As shown in FIG. 17, on the first light-transmitting substrate 101 side, a retardation plate (A) 113, a first polarizing plate (A) 111, and a second polarizing plate (A) 112 are sequentially provided from the substrate side. Place. That is, on the first light-transmitting substrate 101 side, a polarizing plate laminated by the first polarizing plate (A) 111 and the second polarizing plate (A) 112 is configured. In addition, on the second light transmitting substrate 102 side, a retardation plate (B) 123 and a first polarizing plate (B) 121 are arranged in this order from the substrate side. That is, on the second light-transmitting substrate 102 side, the first polarizing plate (B) 121 forms a single-layer polarizing plate. Other configurations are the same as those in FIG.

As shown in FIG. 18, a retardation film (A) 113 and a first polarizing plate (A) 111 are arranged in this order from the substrate side on the first translucent substrate 101 side. That is, on the first light transmitting substrate 101 side, the first polarizing plate (A) 111 constitutes a polarizing plate having a single layer structure. Further, on the second light transmitting substrate 102 side, a retardation plate (B) 123, a first polarizing plate (B) 121, and a second polarizing plate (B) 122 are arranged in this order from the substrate side. That is, on the second light transmitting substrate 102 side, a stacked polarizing plate is configured by the first polarizing plate (B) 121 and the second polarizing plate (B) 122. Other configurations are the same as those in FIG.

In this way, light leakage in the absorption axis direction can also be reduced by having a polarizing plate laminated on one circular polarizing plate and arranging the transmission axes of opposing polarizing plates to be crossed Nicols. it can. As a result, the contrast ratio of the display device can be increased.

(Embodiment 4)
In this embodiment, the concept of a display device using a circularly polarizing plate having stacked polarizing plates and a circularly polarizing plate having one polarizing plate will be described.

As shown in the second embodiment, the opposing polarizing plates are arranged in parallel Nicols. As shown in FIG. 19, on the first light transmitting substrate 201 side, a retardation plate (A) 213, a first polarizing plate (A) 211, and a second polarizing plate (A) are sequentially arranged from the substrate side. 212 is arranged. That is, on the first light-transmitting substrate 201 side, a polarizing plate laminated by the first polarizing plate (A) 211 and the second polarizing plate (A) 212 is configured. Further, on the second light transmitting substrate 202 side, a retardation plate (B) 223 and a first polarizing plate (B) 221 are arranged in this order from the substrate side. That is, on the second light-transmitting substrate 202 side, the first polarizing plate (B) 221 forms a single-layer polarizing plate. Other configurations are the same as those in FIG.

As shown in FIG. 20, a retardation plate (A) 213 and a first polarizing plate (A) 211 are arranged on the first light transmitting substrate 201 side in this order from the substrate side. That is, on the first light-transmitting substrate 201 side, the first polarizing plate (A) 211 forms a single-layer polarizing plate. In addition, a retardation plate (B) 223, a first polarizing plate (B) 221, and a second polarizing plate (B) 222 are arranged in this order from the substrate side on the second light transmitting substrate 202 side. That is, on the second light transmitting substrate 202 side, a stacked polarizing plate is configured by the first polarizing plate (B) 221 and the second polarizing plate (B) 222. Other configurations are the same as those in FIG.

By having a polarizing plate laminated on one circular polarizing plate in this way and arranging it so that the transmission axes of opposing polarizing plates are parallel Nicols, light leakage in the absorption axis direction can also be reduced. it can. As a result, the contrast ratio of the display device can be increased.

(Embodiment 5)
In this embodiment mode, a cross-sectional view of a display device of the present invention is illustrated with reference to FIG.

A thin film transistor is formed over the light-transmitting substrate 201 having an insulating surface with an insulating layer interposed therebetween. A thin film transistor (also referred to as a TFT) is connected to a semiconductor layer processed into a predetermined shape, a gate insulating layer covering the semiconductor layer, a gate electrode provided on the semiconductor layer via the gate insulating layer, and an impurity layer in the semiconductor film Source electrode or drain electrode. The material used for the semiconductor layer is a semiconductor material containing silicon, and the crystalline state may be any of an amorphous state, a microcrystalline state, and a crystalline state. For the insulating layer typified by the gate insulating film, an inorganic material is preferably used, and silicon nitride or silicon oxide can be used. The gate electrode, the source electrode, or the drain electrode may be formed from a conductive material, and includes tungsten, tantalum, aluminum, titanium, silver, gold, molybdenum, copper, and the like. The display device can be broadly divided into a pixel portion 215 and a driver circuit portion 218. The thin film transistor 203 provided in the pixel portion 215 is used as a switching element, and the thin film transistor 204 provided in the driver circuit portion is used as a CMOS circuit. In order to be used as a CMOS circuit, it is composed of a P-channel TFT and an N-channel TFT. The thin film transistor 203 can be controlled by a CMOS circuit provided in the driver circuit portion 218.

An insulating layer having a stacked structure or a single layer structure is formed so as to cover the thin film transistor. The insulating layer can be formed from an inorganic material or an organic material. As the inorganic material, silicon nitride or silicon oxide can be used. As the organic material, polyimide, acrylic, polyamide, polyimide amide, resist, benzocyclobutene, siloxane, or polysilazane can be used. Siloxane has a skeletal structure composed of a bond of silicon (Si) and oxygen (O), and an organic group containing at least hydrogen (such as an alkyl group or aromatic hydrocarbon) is used as a substituent. A fluoro group may be used as a substituent. Alternatively, an organic group containing at least hydrogen and a fluoro group may be used as a substituent. Polysilazane is formed using a liquid material containing a polymer material having a bond of silicon (Si) and nitrogen (N) as a starting material. When formed using an inorganic material, the surface is in a state of following the unevenness on the lower side. When formed using an organic material, the surface is flattened. For example, in the case where flatness is required in the insulating layer 205, an organic material may be used. In addition, even if it is an inorganic material, flatness can be provided by thickening.

The source electrode or the drain electrode is manufactured by forming a conductive layer in an opening provided in the insulating layer 205 or the like. At this time, a conductive layer functioning as a wiring over the insulating layer 205 can be formed. The capacitor 214 can be formed using the conductive layer of the gate electrode, the insulating layer 205, and the conductive layer of the source or drain electrode.

Then, a first electrode 206 connected to any one of the source electrode and the drain electrode is formed. The first electrode 206 is formed using a light-transmitting material. Examples of the light-transmitting material include indium tin oxide (ITO), zinc oxide (ZnO), indium zinc oxide (IZO), and zinc oxide added with gallium (GZO). Further, alkali metals such as Li and Cs, and alkaline earth metals such as Mg, Ca, and Sr, alloys containing these (Mg: Ag, Al: Li, Mg: In, etc.), and compounds thereof (calcium fluoride, In addition to calcium nitride), even non-transparent materials such as rare earth metals such as Yb and Er can be made translucent by having a very thin film thickness. May be used for the first electrode 206.

An insulating layer 210 is formed so as to cover the end portion of the first electrode 206. The insulating layer 210 can be formed in a manner similar to that of the insulating layer 205. An opening is provided in the insulating layer 210 to cover the end portion of the first electrode 206. The end face of the opening may have a taper shape, and a layer formed thereafter can be prevented from being disconnected. For example, when a non-photosensitive resin or a photosensitive resin is used for the insulating layer 210, the side surface of the opening can be tapered depending on the exposure conditions.

Thereafter, an electroluminescent layer 207 is formed in the opening of the insulating layer 210. The electroluminescent layer has a layer having each function, specifically, a hole injection layer, a hole transport layer, a light emitting layer, an electron transport layer, and an electron injection layer. Moreover, the boundary of each layer is not necessarily clear, and some of them may be mixed.

As an example of a material for forming a specific light emitting layer, when red light emission is desired, 4- (dicyanomethylene) -2-isopropyl-6- [2- (1,1,7,7) is added to the light emitting layer. -Tetramethyljulolidin-9-yl) ethenyl] -4H-pyran (abbreviation: DCJTI), 4-dicyanomethylene-2-methyl-6- [2- (1,1,7,7-tetramethyljulolidine- 9-yl) ethenyl] -4H-pyran (abbreviation: DCJT), 4-dicyanomethylene-2-tert-butyl-6- [2- (1,1,7,7-tetramethyljulolidin-9-yl) Ethenyl] -4H-pyran (abbreviation: DCJTB), periflanthene, 2,5-dicyano-1,4-bis [2- (10-methoxy-1,1,7,7-tetramethyljulolidin-9-yl) Ethenyl] Zen, bis [2,3-bis (4-fluorophenyl) quinoxalinato] iridium (acetylacetonate) (abbreviation: Ir _[Fdpq] 2 acac), or the like can be used. However, the present invention is not limited to these materials, and a substance exhibiting light emission having an emission spectrum peak from 600 nm to 700 nm can be used.

When green light emission is desired, N, N′-dimethylquinacridone (abbreviation: DMQd), coumarin 6, coumarin 545T, tris (8-quinolinolato) aluminum (abbreviation: Alq ₃ ), or the like is used for the light emitting layer. Can do. However, the present invention is not limited to these materials, and a substance exhibiting light emission having an emission spectrum peak from 500 nm to 600 nm can be used.

In order to obtain blue light emission, 9,10-bis (2-naphthyl) -tert-butylanthracene (abbreviation: t-BuDNA), 9,9′-bianthryl, 9,10-diphenyl is used in the light-emitting layer. Anthracene (abbreviation: DPA), 9,10-bis (2-naphthyl) anthracene (abbreviation: DNA), bis (2-methyl-8-quinolinolato) -4-phenylphenolato-gallium (abbreviation: BGaq), bis ( 2-methyl-8-quinolinolato) -4-phenylphenolato-aluminum (abbreviation: BAlq) or the like can be used. However, the present invention is not limited to these materials, and a substance exhibiting light emission having an emission spectrum peak from 400 nm to 500 nm can be used.

When white light emission is desired, TPD (aromatic diamine), 3- (4-tert-butylphenyl) -4-phenyl-5- (4-biphenylyl) -1,2,4-triazole (abbreviation) : TAZ), tris (8-quinolinolato) aluminum (abbreviation: _Alq 3), can be used a configuration in which laminated by the _Alq 3, Alq ₃ doped with Nile red which is a red light emitting pigment deposition method.

After that, the second electrode 208 is formed. The second electrode 208 can be formed in a manner similar to that of the first electrode 206. A light-emitting element 209 including the first electrode 206, the electroluminescent layer 207, and the second electrode 208 can be formed.

At this time, since the first electrode 206 and the second electrode 208 have a light-transmitting property, light can be emitted from the electroluminescent layer 207 in both directions. Such a display device capable of emitting light in both directions can be referred to as a dual emission type display device.

After that, the light-transmitting substrate 201 and the counter substrate 220 are attached to each other with a sealing material 228. In this embodiment, since the sealing material 228 is provided over part of the driver circuit portion 218, a narrow frame can be achieved. Needless to say, the arrangement of the sealing material 228 is not limited to this, and may be provided outside the drive circuit portion 218.

An inert gas such as nitrogen is sealed in the space formed by the bonding, or the space is filled with a resin material having a light-transmitting property and a high hygroscopic property. As a result, intrusion of moisture or oxygen that is a cause of deterioration of the light-emitting element 209 can be prevented. In order to maintain a distance between the light-transmitting substrate 201 and the counter substrate 220, a spacer may be provided or the spacer may be hygroscopic. The spacer has a spherical or columnar shape.

The counter substrate 220 can be provided with a color filter or a black matrix. The color filter enables full color display even when a monochromatic light emitting layer, for example, a white light emitting layer is used. Even when each of the RGB light emitting layers is used, by providing a color filter, the wavelength of emitted light can be controlled, and a beautiful display can be provided. Further, the black matrix can reduce reflection of external light due to wiring or the like.

After that, the retardation plate 235, the first polarizing plate 216, the second polarizing plate 217, and the counter substrate 220 are disposed outside the light transmitting substrate 201, the retardation plate 225, the first polarizing plate 226, and the first polarizing plate 226. Two polarizing plates 227 are provided. That is, a circularly polarizing plate having a stacked polarizing plate is provided on the outer side of each of the light transmitting substrate 201 and the counter substrate 220. As a result, black can be sunk and the contrast ratio can be increased.

In this embodiment mode, the driving circuit portion is also formed integrally on the light-transmitting substrate 201; however, the driving circuit portion may be an IC circuit formed from a silicon wafer. In that case, a video signal or the like from the IC circuit can be input to the switching TFT 203 via a connection terminal or the like.

Note that although an active display device is described in this embodiment mode, a circularly polarizing plate including stacked polarizing plates can be provided even in a passive display device. As a result, the contrast ratio can be increased.

This embodiment mode can be freely combined with the above embodiment modes.

(Embodiment 6)
In this embodiment mode, a structure of a display device including a pixel portion and a driver circuit of the present invention will be described.

FIG. 6 is a block diagram illustrating a state where the scan line driver circuit 723 and the signal line driver circuit 722 are provided in the periphery of the pixel portion 700.

The pixel portion 700 includes a plurality of pixels, and each pixel is provided with a light emitting element and a switching element.

The scan line driver circuit 723 includes a shift register 701, a level shifter 704, and a buffer 705. A signal is generated based on the start pulse (GSP) and the clock pulse (GCK) input to the shift register 701 and input to the buffer 705 via the level shifter 704. In the buffer 705, the signal is amplified and input to the pixel portion 700. The pixel portion 700 is provided with a light-emitting element and a switching element for selecting the light-emitting element, and a signal from the buffer 705 is input to a gate line included in the switching element. Then, a switching element of a predetermined pixel is selected.

The signal line driver circuit 722 includes a shift register 711, a first latch circuit 712, a second latch circuit 713, a level shifter 714, and a buffer 715. A start pulse (SSP) and a clock pulse (SCK) are input to the shift register 711, a data signal (DATA) is input to the first latch circuit 712, and a latch pulse (LAT) is input to the second latch circuit 713. ) Is entered. DATA is input to the second latch circuit 713 based on SSP and SCK. The second latch circuit 713 holds DATA for one row and inputs it to the pixel portion 700 all at once.

The signal line driver circuit 722, the scan line driver circuit 723, and the pixel portion 700 can be formed using semiconductor elements provided over the same substrate. For example, the thin film transistor can be formed using the thin film transistor provided over the insulating substrate described in the above embodiment mode.

This embodiment mode can be freely combined with the above embodiment modes.

(Embodiment 7)
In this embodiment, an equivalent circuit diagram of a pixel included in the display device is described with reference to FIGS.

FIG. 7A illustrates an example of an equivalent circuit diagram of a pixel. A signal line 6114, a power supply line 6115, a scanning line 6116, a light-emitting element 6113, transistors 6110 and 6111, and a capacitor element 6112 in an intersection region thereof. Have A video signal (also referred to as a video signal) is input to the signal line 6114 by a signal line driver circuit. The transistor 6110 can control supply of the potential of the video signal to the gate of the transistor 6111 in accordance with a selection signal input to the scan line 6116. The transistor 6111 can control supply of current to the light-emitting element 6113 in accordance with the potential of the video signal. The capacitor 6112 can hold a voltage between the gate and the source of the transistor 6111 (referred to as a gate-source voltage). Note that although the capacitor 6112 is illustrated in FIG. 7A, the capacitor 6112 is not necessarily provided when it can be covered by the gate capacitance of the transistor 6111 or other parasitic capacitance.

FIG. 7B is an equivalent circuit diagram of a pixel in which a transistor 6118 and a scan line 6119 are newly provided in the pixel shown in FIG. The transistor 6118 can set the gate and the source of the transistor 6111 to the same potential and can forcibly prevent a current from flowing to the light-emitting element 6113; therefore, a subframe can be obtained as compared with a period in which a video signal is input to all pixels. The length of the period can be shortened.

FIG. 7C is an equivalent circuit diagram of a pixel in which a transistor 6125 and a wiring 6126 are newly provided in the pixel illustrated in FIG. The potential of the gate of the transistor 6125 is fixed by the wiring 6126. The transistor 6111 and the transistor 6125 are connected in series between the power supply line 6115 and the light-emitting element 6113. Therefore, in FIG. 7C, the value of the current supplied to the light-emitting element 6113 is controlled by the transistor 6125, and the presence or absence of the current supplied to the light-emitting element 6113 can be controlled by the transistor 6111.

Note that the pixel circuit included in the display device of the present invention is not limited to the structure shown in this embodiment mode. For example, the pixel circuit having a current mirror may be configured to perform analog gradation display.

This embodiment mode can be freely combined with the above embodiment modes.

(Embodiment 8)
As an electronic apparatus according to the present invention, a television device (also simply referred to as a television or a television receiver), a camera such as a digital camera or a digital video camera, a mobile phone device (also simply referred to as a mobile phone or a mobile phone), a PDA, or the like Portable information terminals, portable game machines, computer monitors, computers, sound reproduction apparatuses such as car audio, and image reproduction apparatuses equipped with recording media such as home game machines. A specific example will be described with reference to FIG.

A portable information terminal device illustrated in FIG. 8A includes a main body 9201, a display portion 9202, and the like. The display device of the present invention can be applied to the display portion 9202. As a result, a portable information terminal device with a high contrast ratio can be provided.

A digital video camera shown in FIG. 8B includes a display portion 9701, a display portion 9702, and the like. The display device of the present invention can be applied to the display portion 9701. As a result, a digital video camera with a high contrast ratio can be provided.

A cellular phone shown in FIG. 8C includes a main body 9101, a display portion 9102, and the like. The display device of the present invention can be applied to the display portion 9102. As a result, a mobile phone with a high contrast ratio can be provided.

A portable television device illustrated in FIG. 8D includes a main body 9301, a display portion 9302, and the like. The display device of the present invention can be applied to the display portion 9302. As a result, a portable television device with a high contrast ratio can be provided. In addition, the present invention can be applied to a wide variety of television devices, from a small one mounted on a portable terminal such as a cellular phone to a medium-sized one that can be carried and a large one (for example, 40 inches or more). The display device can be applied.

A portable computer illustrated in FIG. 8E includes a main body 9401, a display portion 9402, and the like. The display device of the present invention can be applied to the display portion 9402. As a result, a portable computer with a high contrast ratio can be provided.

A television device illustrated in FIG. 8F includes a main body 9501, a display portion 9502, and the like. The display device of the present invention can be applied to the display portion 9502. As a result, a television device with a high contrast ratio can be provided.

As described above, the display device of the present invention can provide an electronic device with a high contrast ratio.

  In this example, the result of optical calculation using a laminated polarizing plate and retardation plate will be described. The contrast ratio was calculated as the ratio (white transmittance / black transmittance) between the transmittance for white display (referred to as white transmittance) and the transmittance for black display (referred to as black transmittance).

The black display assumes the optical system shown in FIG. Since the black display in the electroluminescence element is a non-light emitting state, the light emitting layer of the electroluminescence element is not provided between the λ / 4 plates, and the display is assumed under the external light, so the backlight is used instead of the external light. It is the arranged optical system. Then, as shown in FIG. 9A, the slow axes of the λ / 4 plates are shifted by 90 degrees, the transmission axes of the polarizing plates facing each other are arranged in a crossed Nicol arrangement, and the laminated polarizing plates are parallel Nicols. As shown in FIG. 9B, the slow axes of the λ / 4 plates were made parallel to each other, the transmission axes of the opposing polarizing plates were arranged in a parallel Nicol arrangement, and the laminated polarizing plates were made parallel Nicols. In the optical system arranged in this way, the transmittance was calculated with respect to the luminance of the backlight by changing the number of polarizing plates to be laminated. The black transmittance is a result of optical calculation in the optical system.

The white display assumes the optical system shown in FIG. In the white display of the electroluminescence element, an optical system using a backlight instead of light emission. As shown in FIG. 10, a λ / 4 plate was disposed on the backlight, a polarizing plate was disposed on the λ / 4 plate, and the opposite λ / 4 plate was not disposed. At this time, the transmission axis of the polarizing plate is arranged to deviate by 45 degrees with respect to the slow axis of the λ / 4 plate. The polarizing plate to be laminated was parallel Nicol. In the optical system thus arranged, the transmittance was calculated with respect to the luminance of the backlight by changing the number of polarizing plates. Since the optical system of white transmittance shown in FIG. 10 is arranged by shifting the transmission axis of the polarizing plate by 45 degrees with respect to the slow axis of the λ / 4 plate, the crossed Nicols arrangement of FIG. The white transmittance in both cases is arranged in parallel Nicol in FIG. 9B.

The calculation in this example uses an optical calculation simulator LCD MASTER (manufactured by Shintech Co., Ltd.) for liquid crystal. When calculating the transmittance with respect to the wavelength using the LCD MASTER, the 2 × 2 matrix optical calculation algorithm that does not consider multiple interference between elements is used, and the light source wavelength is set at 10 nm intervals from 380 nm to 780 nm. Asked. As the λ / 4 plate, a retardation plate having a retardation of 137.5 nm in the entire wavelength region of 380 nm to 780 nm was used. Further, the polarizing plate has a refractive index n of n = n ′ + in ″, and the transmission axes n ′ and n ″ are n ′ = 1.5 and n ″ = 3.22 × e at a wavelength of 550 nm, respectively. A polarizing plate having a absorption axis of n ′ and n ″ of n ′ = 1.5 and n ″ = 2.21 × e−3 was used. In addition, a D65 light source was used as the backlight, and the polarization state was set to mixed circular polarization.

FIG. 11 shows the calculation result of the contrast ratio when the number of polarizing plates is changed when the opposing polarizing plates are arranged in a crossed Nicol arrangement as shown in FIG. The contrast ratio was obtained from the black transmittance of the optical system shown in FIG. 9A and the white transmittance value of the optical system shown in FIG. The legend BL \ 2 × 1 in the figure is that the backlight (BL) is arranged in FIG. 9A, the number of polarizing plates on the backlight side is two, and the number of polarizing plates on the viewing side is one. Indicates that there is. Similarly, legends such as BL \ 1 × 1, BL \ 2 × 2, BL \ 1 × 2, BL \ 3 × 1 mean the number of polarizing plates on the backlight side and the number of polarizing plates on the viewing side.

The legend in the figure is applied to the optical system shown in FIG. That is, if BL \ 2 × 1 in the figure, the last number is “1”, which means that the calculation result of one polarizing plate in FIG. 10 is used. Similarly, only the last number is applied to BL \ 1 × 1, BL \ 2 × 2, BL \ 1 × 2, BL \ 3 × 1, etc., and these indicate the number of polarizing plates.

The contrast ratio of the thus-arranged sample was determined from the ratio of white transmittance to black transmittance (white transmittance / black transmittance).

FIG. 11A shows that the contrast ratio increases as the number of polarizing plates increases by one on each side. FIG. 11B shows that the contrast ratio increases even if the number of polarizing plates is increased by one on one side. Compared to the same number of polarizing plates on the backlight side and viewing side, such as BL \ 1x2 and BL \ 2x1, the black transmittance is the same, but the white transmission is the same. The rate is higher when the number of viewing side polarizing plates is smaller. For this reason, the contrast ratio increases as the number of viewing-side polarizing plates decreases. From FIG. 11C, when the total number of polarizing plates is the same, such as BL \ 2 × 2 and BL \ 3 × 1, the contrast ratio becomes larger when the number of polarizing plates on each side is two or more.

Next, FIG. 12 shows the calculation result of the contrast ratio when the number of polarizing plates is changed when the opposing polarizing plates in FIG. 9B are arranged in parallel Nicols. FIG. 12A shows that the contrast ratio increases as the number of polarizing plates increases on each side. Further, from FIG. 12B, the contrast ratio increases even if the number of polarizing plates is increased by one on one side. Compared to the same number of polarizing plates on the backlight side and viewing side, such as BL \ 1x2 and BL \ 2x1, the black transmittance is the same, but the white transmission is the same. The rate is higher when the number of viewing side polarizing plates is smaller. For this reason, the contrast ratio increases as the number of viewing-side polarizing plates decreases. From FIG. 12C, when the total number of polarizing plates is the same, such as BL \ 2 × 2, BL \ 3 × 1, the contrast ratio becomes larger when the number of polarizing plates on each side is two or more.

From the above results, it can be seen that the contrast ratio increases as the number of polarizing plates increases, regardless of whether the opposing polarizing plates are arranged in crossed Nicols or parallel Nicols. When the number of polarizing plates is an odd number, it can be seen that the smaller the number of polarizing plates on the viewing side, the greater the contrast ratio. When the total number of polarizing plates is the same, the contrast ratio becomes larger when the number of polarizing plates on each side is two or more.

Comparing FIG. 11 and FIG. 12, the contrast ratio is high in a wide wavelength region when the opposing polarizing plates are arranged in crossed Nicols. On the other hand, when the opposing polarizing plates are arranged in parallel Nicols, it is possible to increase the contrast only in the vicinity of a wavelength of 550 nm.

FIG. 13 shows the wavelength dispersion characteristics of the transmittance when BL \ 1 × 1. It can be seen that when the opposing polarizing plates are arranged in crossed Nicols, the transmittance is low in a wide wavelength region. On the other hand, when the opposing polarizing plates are arranged in parallel Nicols, it can be seen that the transmittance is low only in the vicinity of the wavelength of 550 nm. On the other hand, the white transmittance was the same whether the opposing polarizing plates were in a crossed Nicol arrangement or a parallel Nicol arrangement. For this reason, there is a difference in contrast ratio between the opposing polarizing plates between the crossed Nicols arrangement and the parallel Nicols arrangement.

By arranging the transmission axes of the polarizing plates to be stacked in this way so as to be parallel Nicols, light leakage can be reduced. Then, by providing a circularly polarizing plate in which the opposing polarizing plates are arranged so as to be parallel Nicols or crossed Nicols, the opposing single-layered polarizing plates are arranged so as to be parallel Nicols or crossed Nicols. Light leakage can be reduced compared to a polarizing plate. As a result, the contrast ratio of the display device can be increased. Note that the opposing polarizing plates preferably have a crossed Nicols arrangement, and a high contrast ratio can be obtained over a wide band.

In this example, experimental results of wavelength dispersion characteristics of black transmittance when two opposing circularly polarizing plates are arranged in a crossed Nicol arrangement and in a parallel Nicol arrangement will be described. The black luminance and white luminance were measured for each sample, and the contrast ratio, which is the ratio of white luminance to black luminance (white luminance / black luminance), was calculated. The contrast ratio of Example 1 was obtained from (white transmittance / black transmittance), but the black transmittance was obtained from (black luminance / reference backlight luminance), and the white transmittance was (white luminance / reference). Therefore, the contrast ratio can be calculated from both (white transmittance / black transmittance) and (white luminance / black luminance).

First, as shown in FIGS. 9A and 9B, two circularly polarizing plates WB-CP-W (manufactured by Sumitomo Chemical Co., Ltd.) have transmission axes of polarizing plates facing each other in a crossed Nicols arrangement or a parallel Nicols arrangement. Then, the wavelength dispersion characteristic of transmittance was measured with a self-recording spectrophotometer U-4000 (manufactured by Hitachi, Ltd.). Here, the number of polarizing plates on both sides was measured as one.

The results are shown in FIG. Similar to the result of Example 1, it can be seen that the crossed Nicol arrangement has lower transmittance than the parallel Nicol arrangement. In particular, a large difference in transmittance appears from a wavelength of 630 nm to 780 nm.

Therefore, when the transmission axes of the polarizing plates facing each other are in a crossed Nicols arrangement, the black luminance and the white luminance were measured, and the contrast ratio was calculated. FIG. 15A shows an optical system for measuring black luminance, and FIG. 15B shows an optical system for measuring white luminance. Here, the optical system is shown with three backlight-side polarizing plates and three viewing-side polarizing plates. As the circularly polarizing plate, WB-CP-W (manufactured by Sumitomo Chemical Co., Ltd.) was used, and as the polarizing plate to be laminated, NPF-EG1425DU (manufactured by Nitto Denko Corporation) was used. Note that the polarizing plate to be laminated is used by being attached to a glass substrate, but the transmittance of the glass substrate is high and it is considered that the results of this experiment are not affected. In the experiment, the luminance when the number of polarizing plates stacked in a dark room was changed was measured with a color luminance meter BM5A, and the contrast ratio was calculated.

The calculation result of the contrast ratio is shown in FIG. It can be seen that the contrast ratio increases as the number increases on each side. However, since the contrast ratio is substantially the same between BL \ 3 × 3 and BL \ 4 × 4, it can be said that the contrast ratio is saturated when three polarizing plates are provided on both sides.

By arranging the transmission axes of the polarizing plates to be stacked in this way so as to be parallel Nicols, light leakage can be reduced. And by providing circularly polarizing plates arranged so that the opposing polarizing plates are crossed Nicols, compared to the circularly polarizing plates arranged so that the opposing single-layered polarizing plates are crossed Nicols Light leakage can be reduced. As a result, the contrast ratio of the display device can be increased. Note that the opposing polarizing plates preferably have a crossed Nicols arrangement, and a high contrast ratio can be obtained over a wide band. The number of laminated polarizing plates is preferably three.

It is the figure which showed the display apparatus of this invention It is the figure which showed the optical axis of this invention It is the figure which showed the display apparatus of this invention It is the figure which showed the optical axis of this invention It is the figure which showed the display apparatus of this invention It is the block diagram which showed the display apparatus of this invention FIG. 6 is a diagram illustrating a pixel circuit included in a display device of the present invention. It is the figure which showed the electronic device of this invention FIG. 3 is a diagram illustrating a black transmittance measurement system of Example 1. It is the figure which showed the measurement system of the white transmittance of Example 1. It is the figure which showed the measurement result of Example 1. It is the figure which showed the measurement result of Example 1. It is the figure which showed the measurement result of Example 1. It is the figure which showed the measurement result of Example 2. It is the figure which showed the measurement system of Example 2. It is the figure which showed the measurement result of Example 2. It is the figure which showed the display apparatus of this invention It is the figure which showed the display apparatus of this invention It is the figure which showed the display apparatus of this invention It is the figure which showed the display apparatus of this invention

Claims (7)

The first translucent substrate and the second translucent substrate are disposed so that the first translucent substrate and the second translucent substrate are opposed to each other, and are provided between the opposed substrates. A light emitting element that emits light in both directions,
A first circularly polarizing plate disposed on the outside of the first translucent substrate and having a stacked first linearly polarizing plate;
And a second circularly polarizing plate disposed outside the second light-transmitting substrate and having a stacked second linearly polarizing plate. The first translucent substrate and the second translucent substrate are disposed so that the first translucent substrate and the second translucent substrate are opposed to each other, and are provided between the opposed substrates. A light emitting element that emits light in both directions,
A first circularly polarizing plate disposed on the outside of the first translucent substrate and having a stacked first linearly polarizing plate;
A second circularly polarizing plate disposed on the outside of the second light-transmitting substrate and having a stacked second linearly polarizing plate,
The transmission axes of the laminated first linearly polarizing plates are arranged so as to be parallel Nicols,
The transmission axes of the laminated second linearly polarizing plates are arranged so as to be parallel Nicols,
The display device, wherein the transmission axis of the laminated first linearly polarizing plate and the transmission axis of the laminated second linearly polarizing plate are arranged in parallel Nicols. The first translucent substrate and the second translucent substrate are disposed so that the first translucent substrate and the second translucent substrate are opposed to each other, and are provided between the opposed substrates. A light emitting element that emits light in both directions,
A laminated first linearly polarizing plate disposed outside the first light-transmitting substrate;
A laminated second linearly polarizing plate disposed outside the second light-transmitting substrate;
A first retardation plate provided between the first translucent substrate and the first linear polarizing plate;
A second retardation plate provided between the second translucent substrate and the second linearly polarizing plate,
The transmission axes of the laminated first linearly polarizing plates are arranged so as to be parallel Nicols,
The transmission axes of the laminated second linearly polarizing plates are arranged so as to be parallel Nicols,
The transmission axis of the laminated first linearly polarizing plate and the transmission axis of the laminated second linearly polarizing plate are arranged to be parallel Nicols,
With respect to the transmission axis of the first linearly polarizing plate, the slow axis of the first retardation plate is 45 °,
A display device, wherein a slow axis of the second retardation plate is 45 ° with respect to a transmission axis of the second linear polarizing plate. The first translucent substrate and the second translucent substrate are disposed so that the first translucent substrate and the second translucent substrate are opposed to each other, and are provided between the opposed substrates. A light emitting element that emits light in both directions,
A laminated first linearly polarizing plate disposed outside the first light-transmitting substrate;
A second linearly polarizing plate disposed outside the second light-transmitting substrate;
A first retardation plate provided between the first translucent substrate and the first linear polarizing plate;
A second retardation plate provided between the second translucent substrate and the second linearly polarizing plate,
The transmission axes of the laminated first linearly polarizing plates are arranged so as to be parallel Nicols,
The transmission axis of the laminated first linearly polarizing plate and the transmission axis of the second linearly polarizing plate are arranged to be parallel Nicols,
With respect to the transmission axis of the first linearly polarizing plate, the slow axis of the first retardation plate is 45 °,
A display device, wherein a slow axis of the second retardation plate is 45 ° with respect to a transmission axis of the second linear polarizing plate. The first translucent substrate and the second translucent substrate are disposed so that the first translucent substrate and the second translucent substrate are opposed to each other, and are provided between the opposed substrates. A light emitting element that emits light in both directions,
A first circularly polarizing plate disposed on the outside of the first translucent substrate and having a stacked first linearly polarizing plate;
A second circularly polarizing plate having a stacked second linearly polarizing plate disposed outside the second translucent substrate;
The transmission axes of the laminated first linearly polarizing plates are arranged so as to be parallel Nicols,
The transmission axes of the laminated second linearly polarizing plates are arranged so as to be parallel Nicols,
A display device, wherein the transmission axis of the laminated first linearly polarizing plate and the transmission axis of the laminated second linearly polarizing plate are arranged to be crossed Nicols. The first translucent substrate and the second translucent substrate are disposed so that the first translucent substrate and the second translucent substrate are opposed to each other, and are provided between the opposed substrates. A light emitting element that emits light in both directions,
A laminated first linearly polarizing plate disposed outside the first light-transmitting substrate;
A laminated second linearly polarizing plate disposed outside the second light-transmitting substrate;
A first retardation plate provided between the first translucent substrate and the first linear polarizing plate;
A second retardation plate provided between the second translucent substrate and the second linearly polarizing plate,
The transmission axes of the laminated first linearly polarizing plates are arranged so as to be parallel Nicols,
The transmission axes of the laminated second linearly polarizing plates are arranged so as to be parallel Nicols,
The transmission axis of the laminated first linearly polarizing plate and the transmission axis of the laminated second linearly polarizing plate are arranged to be crossed Nicols,
With respect to the transmission axis of the first linear polarizer, the slow axis of the first retardation plate is arranged to be 45 °,
A display device, wherein the second retardation plate is disposed at 45 ° with respect to a transmission axis of the second linear polarizing plate. The first translucent substrate and the second translucent substrate are disposed so that the first translucent substrate and the second translucent substrate are opposed to each other, and are provided between the opposed substrates. A light emitting element that emits light in both directions,
A laminated first linearly polarizing plate disposed outside the first light-transmitting substrate;
A second linearly polarizing plate disposed outside the second light-transmitting substrate;
A first retardation plate provided between the first translucent substrate and the first linear polarizing plate;
A second retardation plate provided between the second translucent substrate and the second linearly polarizing plate,
The transmission axes of the laminated first linearly polarizing plates are arranged so as to be parallel Nicols,
The transmission axis of the laminated first linearly polarizing plate and the transmission axis of the second linearly polarizing plate are arranged to be crossed Nicols,
With respect to the transmission axis of the first linear polarizer, the slow axis of the first retardation plate is arranged to be 45 °,
A display device, wherein the second retardation plate is disposed at 45 ° with respect to a transmission axis of the second linearly polarizing plate.

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