JP2002359068A - EL device, EL display, EL lighting device, liquid crystal device using the same, and electronic equipment - Google Patents

Abstract

(57) [Summary] [Problem] Of light emitted from a light emitting layer, light incident on a light transmissive substrate at less than a critical angle can be emitted to the outside with low scattering, and incident on the light transmissive substrate at a critical angle or more. Provided is an EL display which can emit light to the outside and improve the brightness in the front direction. SOLUTION: A plurality of EL elements 10 are arranged in a matrix on one surface of a light transmissive substrate 1, and a pair of electrodes 2,
5, at least the electrode 2 located on the side of the substrate 1 is formed of a light-transmitting electrode, and a partition 8 is provided around the EL element 10.
Is provided so that the EL element 10 can be individually energized. When the EL element 10 is energized, the light emitted from the light emitting layer 4 is emitted to the substrate 1 side. An optical unit 20 is provided on the surface, and the optical unit 20 scatters and / or diffracts, out of the light from the light emitting layer 4, which has entered the substrate 1, the light L <b> 1 that repeats at least part of total reflection, and emits the light to the outside. And the other light L3 is weakly scattered and / or transmitted and emitted to the outside.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an EL device having an EL element (electroluminescence element), and more particularly, to an EL device having improved luminance in a front direction.
The present invention relates to an EL display, an EL lighting device, a liquid crystal device using the same, and an electronic apparatus.

[0002]

2. Description of the Related Art An EL display is known as a kind of an EL device using an EL element. An outline of a configuration example of a conventional EL display will be described below with reference to the drawings.
FIG. 18 is a schematic sectional view showing an example of a conventional EL display. A conventional EL display has a transparent substrate 801.
And an EL provided on one surface of the transparent substrate 801.
It is schematically composed of an element 812. EL element 812
Stands for Indium Tin Oxide (I)
Abbreviated as TO. ), A transparent electrode 813 functioning as an anode, a hole transport layer 814 facilitating injection of holes from the transparent electrode 813, a light emitting layer 815 made of an EL material, and a metal electrode 816 functioning as a cathode. The transparent electrodes 813 and the metal electrodes 816 are stacked in this order from the substrate 801 side, with the light emitting layer 815 interposed therebetween. An EL display provided with such an EL element 812 can emit a predetermined amount of current through the transparent electrode 813 and the metal electrode 816 so that the light emitting layer 815 can be formed.
Light from the light emitting layer 815 and the transparent electrode 81
3 and the transparent substrate 801, and is emitted from the transparent substrate 801 side to the outside of the EL element 812.

However, of the light emitted from the light emitting layer 815, the light emitted to the transparent substrate 801 at a wide angle (above the critical angle) repeats total reflection within the transparent substrate 801 and the transparent substrate 8
01 is not released to the outside. That is, when the light incident on the transparent substrate 801 has a wide angle (equal to or greater than the critical angle), the light is not used as a display, so that the luminance is low. In addition,
When light incident from the medium having the refractive index n1 at an angle of θ1 advances to the medium having the refractive index n2 at the refraction angle of θ2, θ1, θ
The following relationship (Snell's law) is established between 2, n1, and n2: n1 sin θ1 = n2 sin θ2. In order to determine the critical angle of light incident on the transparent substrate 801, since a transparent substrate such as a glass substrate or an acrylic resin is usually used as the transparent substrate 801, n1 = 1.49 to 1.6. Since the refractive index of air is 1, n2 = 1, and the transparent substrate 8 when the transmitted light when the incident light is at a critical angle is parallel to the surface of the transparent substrate 801
01 is about 40 ° because the angle θ2 from the normal direction H of H.01 is 90 °.
The critical angle of the light incident on 01 is about 40 °.

Therefore, in the conventional EL display, even if the light incident on the transparent substrate 801 is at a critical angle or more, it can be extracted outside the transparent substrate 801 as shown in FIG. Isotropically obtained by dispersing metal oxide particles as a filler in a substrate made of, for example, a 50 to 200 μm-thick triallyl cyanate on a surface opposite to the surface on which the EL element 812 is provided. By forming the scattering layer 820 having a scattering property, even when the light incident on the transparent substrate 801 (the light emitted from the light emitting layer 815 and emitted to the transparent substrate 801) has a critical angle or more, the transparent substrate 801 can be used. So that it can be taken out.

[0005]

However, in the conventional EL display provided with the scattering layer 820 as described above, as shown in FIG. 18, incident light L10 having a critical angle or more incident on the transparent substrate 801 isotropically. Although it is possible to scatter light (transmitted light L11 isotropically scattered) and take it out of the transparent substrate 801, the incident light L12 incident on the transparent substrate 801 and having a critical angle less than the critical angle is also isotropic. Scattered (the transmitted light L13 isotropically scattered), the brightness when viewed from a wide viewing angle is bright, but the brightness when viewed from the front (normal direction and its vicinity) is low. However, there is a problem that the display becomes dark. Further, as another means for extracting light outside the transparent substrate 801 even when the light incident on the transparent substrate 801 has a critical angle or more, there is a method in which the surface of the transparent substrate 801 is roughened to provide irregularities. Also in this case, similarly to the case where the scattering layer 820 is provided, there is a problem that the brightness when viewed from the front direction is low and the display becomes dark.

The present invention has been made in view of the above circumstances, and among the light emitted from the light emitting layer, light incident on the light transmitting substrate at a narrow angle (less than the critical angle) is emitted to the outside with low scattering. It is an object of the present invention to provide an EL device capable of emitting light incident on a light-transmitting substrate at a wide angle (equal to or greater than the critical angle) to the outside, and improving the luminance in the front direction (normal direction and directions in the vicinity thereof). Another object of the present invention is to provide an EL display which can obtain a bright display and improve the display quality by using such an EL device having improved luminance in the front direction as an EL display. In addition, the present invention provides such an E-type with improved brightness in the front direction.
Another object is to use the L device as an EL lighting device. Another object of the present invention is to provide a liquid crystal device provided with such an EL lighting device with improved brightness in the front direction. Another object of the present invention is to provide an electronic device provided with a liquid crystal device using an EL display or an EL lighting device with improved luminance in the front direction as a display means.

[0007]

In order to solve the above problems, an EL device according to the present invention comprises at least one light emitting layer including a light emitting layer.
A plurality of EL elements each including one organic layer and a pair of electrodes facing each other with the organic layer interposed therebetween are arranged in a matrix on one surface of the light-transmitting substrate, and at least one of the pair of electrodes The electrode located on the transmissive substrate side is formed of a light transmissive electrode, and can be individually energized to the EL element. When the EL element is energized, light emitted from the light emitting layer transmits the light. An EL device emitted to the transparent substrate side, wherein an optical unit is provided on the other surface of the light transmitting substrate, and the optical unit transmits light out of the light emitted from the light emitting layer into the light transmitting substrate. Light that repeats at least part of total reflection is scattered and / or diffracted and emitted to the outside, and other light is weakly scattered and / or transmitted and emitted to the outside. In such an EL device, since the optical means having the above-described configuration is provided on the other surface of the light-transmitting substrate, at least one of the light from the light-emitting layer incident on the light-transmitting substrate is provided. Light incident at an angle that repeats partial total reflection (light incident on a light-transmitting substrate at a wide angle (critical angle or more)) can be scattered and / or diffracted and emitted to the outside. Light (light incident on the light-transmitting substrate at a narrow angle (less than the critical angle)) can be weakly scattered and / or transmitted and emitted to the outside, so that a scattering layer having an isotropic scattering characteristic or a transparent layer Brightness in the front direction (in the normal direction and in the vicinity thereof) can be improved as compared with a conventional device in which unevenness is provided on the surface of the substrate. That is, the EL device of the present invention scatters and / or diffracts at least a part of the light incident on the light transmissive substrate at a wide angle (above the critical angle), and transmits light at a narrow angle (below the critical angle). By providing on the surface of the light transmissive substrate as a support substrate for the EL element, optical means capable of having no or little effect on light incident on the substrate, avoiding the total reflection condition, Light emitted almost straight in the front direction (normal direction and its vicinity direction) is not scattered, and light emitted from the light emitting layer is efficiently extracted (emitted) to the outside. The brightness in the direction can be improved.

In order to solve the above-mentioned problems, an EL device according to the present invention is an EL device comprising at least one organic layer including a light-emitting layer and a pair of electrodes facing each other via the organic layer. The electrode disposed on one surface of the transmissive substrate, and at least one of the pair of electrodes located on the light transmissive substrate side is formed of a light transmissive electrode.
An EL device which is configured to be able to conduct electricity to the L element and emits light emitted from the light emitting layer to the light transmissive substrate side when the EL element is energized, and the other of the light transmissive substrates. Optical means is provided on the surface, and the optical means scatters and / or diffracts at least a part of the light from the light emitting layer, which is incident on the light transmitting substrate and repeats total reflection, and emits the light to the outside. , And other light is weakly scattered and / or transmitted and emitted to the outside. Also in the EL device having such a configuration, the brightness in the front direction (in the normal direction and in the vicinity thereof) is improved by providing the optical means having the above configuration on the other surface of the light transmitting substrate. it can.

Further, the EL of the present invention having any one of the above structures
In the device, the optical means may strongly scatter at least a part of the incident light having a critical angle or more out of the light from the light-emitting layer incident on the light-transmitting substrate and emit the light to the outside; Light may be weakly scattered or transmitted and emitted to the outside. In such an EL device, the optical means having the above-described structure is provided on the other surface of the light-transmitting substrate, so that the light from the light-emitting layer incident on the light-transmitting substrate becomes critical. At least a part of incident light having an angle or more can be strongly scattered and emitted to the outside, and incident light having a critical angle or less is weakly scattered or transmitted (no scattering).
In other words, light that is emitted almost straight in the front direction (normal direction and its vicinity) can be prevented from scattering or transmitted as much as possible. Therefore, the luminance in the front direction can be improved. In addition, the optical unit diffracts at least a part of incident light having a critical angle or more out of the light from the light emitting layer incident on the light transmissive substrate and emits it to the outside, and transmits incident light having a critical angle or less. And may be emitted to the outside. In such an EL device,
By providing the optical means having the above configuration on the other surface of the light transmitting substrate, at least a critical angle or more of the light from the light emitting layer incident on the light transmitting substrate. Some can be diffracted and emitted to the outside,
The incident light having a critical angle smaller than the critical angle can be transmitted and emitted to the outside, that is, the total reflection condition can be avoided, and the light emitted almost straight in the front direction (the normal direction and the vicinity thereof) can be transmitted. Therefore, the luminance in the front direction can be improved. In addition, the optical unit may be configured to strongly scatter and diffract at least a part of the incident light having a critical angle or more out of the light from the light emitting layer incident on the light transmissive substrate and emit the light to the outside. The light may be weakly scattered and / or transmitted and emitted to the outside. In such an EL device, the optical unit having the above-described configuration is provided on the other surface of the light-transmitting substrate.
At least a part of the incident light having a critical angle or more among the light from the light emitting layer incident on the light transmitting substrate can be strongly scattered and diffracted and emitted to the outside, and the incident light having a critical angle or less is weakly scattered. And / or can be transmitted and emitted to the outside, that is, it is possible to avoid the condition of total reflection and to minimize scattering of light emitted almost straight in the front direction (normal direction and its vicinity direction) as much as possible. , And / or transmission, so that the luminance in the front direction can be improved.

Further, the EL of the present invention having any one of the above structures
In the device, the optical unit may include β1 ≧ sin of light from the light emitting layer incident on the light transmitting substrate.
^-1 (1 / m1) (where β1 is the inclination angle of the light-transmitting substrate from the normal direction, 1 is the refractive index of air, and m1 is the refractive index of the light-transmitting substrate.) At least a part of the incident light satisfying the condition is scattered and / or diffracted and emitted to the outside, and the incident light satisfying the condition of β1 <sin ^-1 (1 / m1) is weakly scattered and / or transmitted and emitted to the outside. It may be something. The value of the inclination angle β1 from the normal direction of the light-transmitting substrate when the light incident on the light-transmitting substrate shows a critical angle or more is determined by the Snell's law (n1 sin
θ1 = n2 sin θ2), where n1 = m1 and
Since the refractive index of air is 1, n2 = 1, θ1 = β1,
The angle θ from the normal direction of the light transmitting substrate when the transmitted light is parallel to the surface of the light transmitting substrate when the incident light is at a critical angle.
2 is 90 °, β1 ≧ sin ⁻¹ (1 / m
1) can be calculated. Therefore, the optical means may determine that β1 ≧ s out of the light from the light emitting layer incident on the light transmitting substrate.
At least a part of incident light satisfying a condition of in ⁻¹ (1 / m1) can be scattered and / or diffracted, and β1 <sin ^−1.
The incident light satisfying the condition (1 / m1) is weakly scattered and / or
Alternatively, if the light can be transmitted, the light incident on the light-transmitting substrate at an angle such that total reflection is repeated out of the light from the light-emitting layer incident on the light-transmitting substrate (wide angle (critical angle or more)). At least a part of the light) can be scattered and / or diffracted and emitted to the outside, and weakly scatter and / or scatter other light (light incident on the light transmitting substrate at a narrow angle (less than the critical angle)). It can be transmitted and emitted to the outside.

The above-mentioned optical means has a transient state of about 10 ° to about 20 ° when light incident thereon exhibits strong scattering and / or diffraction and weak scattering and / or transmission. The optical means is preferably optimized so that incident light having an angle deviating from the critical angle of the incident light incident on the light transmitting substrate by about 10 ° can be scattered and / or diffracted. Therefore, the optical means is capable of transmitting β1 out of the light from the light emitting layer incident on the light transmitting substrate.
≧ sin ⁻¹ (1 / m1) −10 ° (where β1
Is the inclination angle of the light transmitting substrate from the normal direction, 1 is the refractive index of air, and m1 is the refractive index of the light transmitting substrate. )
At least a part of the incident light satisfying the condition is scattered and / or diffracted and emitted to the outside, and β1 <sin ⁻¹ (1 / m1) −
It is preferable that the incident light satisfying the condition of 10 ° be emitted to the outside after being weakly scattered and / or transmitted.

[0012] The optical means may include a condition that β1 ≧ 40 ° out of the light from the light emitting layer incident on the light transmitting substrate (where β1 is an inclination from a normal direction of the light transmitting substrate). At least a part of the incident light satisfying the angle (1) is strongly scattered and / or diffracted and emitted to the outside, and the incident light satisfying the condition of β1 = 0 is weakly scattered and / or transmitted and emitted to the outside. Is also good. To determine a specific value (approximate value) of the inclination angle β1 from the normal direction of the light transmitting substrate when the light incident on the light transmitting substrate shows a critical angle or more,
As the light transmissive substrate, a glass substrate or a transparent resin such as an acrylic resin can be used, and their refractive indices are 1.49 to 1.6 (n1 = 1.49 to 1.6); When the refractive index of air is 1 (n2 = 1) and the transmitted light when the incident light is at a critical angle is parallel to the surface of the light-transmitting substrate, the angle θ2 from the normal direction of the light-transmitting substrate is 90 °
From the above Snell's law, θ1 is about 4
The critical angle β1 of the light incident on the light transmitting substrate is about 40 °. Therefore, the optical means is
Β out of the light from the light emitting layer incident on the light transmitting substrate
At least a part of the incident light satisfying the condition of 1 ≧ 40 ° can be strongly scattered and / or diffracted, and the incident light satisfying the condition of β1 = 0 can be weakly scattered and / or transmitted. Strongly scatter and / or diffract at least a part of the light (the light incident on the light transmitting substrate at a wide angle (greater than or equal to the critical angle)) incident at an angle such that total reflection is repeated out of the light emitted from the light emitting layer. As a result, light emitted straight in the front direction (normal direction) can be weakly scattered and / or transmitted and emitted to the outside.

[0013] The optical means may include a condition that β1 ≧ 40 ° out of the light from the light emitting layer incident on the light transmitting substrate (where β1 is the inclination of the light transmitting substrate from the normal direction). At least a part of the incident light satisfying the angle
Alternatively, it is preferable that the incident light that is diffracted and emitted to the outside and that satisfies the condition of β1 <40 ° is one that is weakly scattered and / or transmitted and emitted to the outside. If the optical means satisfies such a condition, of the light from the light emitting layer incident on the light transmissive substrate, light incident at an angle such that total reflection is repeated (wide angle (critical angle or more)) At least a portion of the light incident on the light-transmitting substrate) can be strongly scattered and / or diffracted and emitted to the outside, and the incident light less than the critical angle is weakly scattered and / or transmitted and almost emitted to the outside. be able to.

The E of the present invention having any one of the above structures
In the L device, the optical means may be the light emitting layer.
From the light-transmitting substrate to the optical means.
Chi β2 ≧ sin^-1(1 / m2) (where β2 is
Angle of inclination of the optical means from the normal direction, 1 is refraction of air
The index, m2, is the refractive index of the optical means. ) Fill incident light
Is scattered and / or diffracted to the outside
Outgoing, β2 <sin ^-1Satisfies the condition (1 / m2)
Incident light is weakly scattered and / or transmitted and exits to the outside
It may be something. Light incident on the above optical means is critical
The inclination of the above optical means from the normal direction when showing an angle or more
The value of the angle β2 is determined by the above Snell's law (n1 sin θ1 =
n2 sin θ2), n1 = m2,
Since the refractive index is 1, n2 = 1, θ1 = β2, incident light
Is parallel to the surface of the light-transmitting substrate when
When the angle θ2 from the normal direction of the light transmitting substrate is 9
0 °, β2 ≧ sin^-1(1 / m2) and
Can be calculated. Therefore, the optical means is provided by the light emitting layer.
Of the light incident on the optical means through the light transmitting substrate
β2 ≧ sin^-1Of incident light satisfying the condition (1 / m2)
At least some can be scattered and / or diffracted, and β2 <
sin^-1Incident light satisfying the condition (1 / m2) is weakly scattered
And / or if it can be transmitted, the light emitting layer
From the light-transmitting substrate to the optical means.
Light incident at an angle that repeats total reflection (wide-angle
At least a part of the light) incident on the optical means at a field angle or more.
Can be scattered and / or diffracted and emitted to the outside
It can be used with other light (narrow angle (less than critical angle)
Weakly scattered and / or transmitted through the stage)
Can be emitted.

[0015] The transition state of the angle when the incident light incident on the optical means from the light emitting layer via the light transmitting substrate shows strong scattering and / or diffraction and weak scattering by the optical means is about 10 °. Since there is a range of about 20 ° to about 20 °, it is possible to scatter and / or diffract incident light having an angle deviating from the critical angle of about 10 ° from the critical angle of the incident light incident on the optical means via the light transmitting substrate. Thus, it is preferable to optimize the optical means. Therefore, the optical means is configured such that β2 ≧ sin ⁻¹ (1 / m2) −1 of light incident on the optical means from the light emitting layer via the light transmitting substrate.
At least part of the incident light that satisfies the condition of 0 ° (where β2 is the inclination angle of the optical unit from the normal direction, 1 is the refractive index of air, and m2 is the refractive index of the optical unit) is scattered. And / or diffracted and emitted to the outside, β2 <sin
It is preferable that the incident light satisfying the condition of ^-1 (1 / m2) -10 ° be light scattered and / or transmitted and emitted to the outside.

[0016] The optical means may include β of light incident on the optical means from the light emitting layer through the light transmitting substrate.
At least a part of the incident light satisfying the condition of 2 ≧ 40 ° (where β2 is the inclination angle from the normal direction of the optical means) is strongly scattered and / or diffracted and emitted to the outside, and β2 = 0.
The incident light satisfying the condition of ° may be weakly scattered and / or transmitted and emitted to the outside. To determine a specific value (approximate value) of the inclination angle β2 from the normal direction of the optical means when light incident on the optical means from the light emitting layer via the light transmitting substrate shows a critical angle or more. Has an average refractive index of about 1.5 in the optical means.
7 (n1 = 1.57), and the refractive index of air is 1
(N2 = 1), and the angle θ2 from the normal direction of the optical means when the transmitted light is parallel to the surface of the optical means when the incident light is at a critical angle is 90 °, so that the above Snell According to the law, θ1 is about 40 °, and therefore, the critical angle β2 of the light incident on the optical means is about 40 °. Therefore, the optical means may be configured such that at least a part of incident light satisfying the condition of β2 ≧ 40 ° among light incident on the optical means from the light emitting layer via the light transmitting substrate is strongly scattered and / or
Alternatively, if the incident light that satisfies the condition of β2 = 0 can be weakly scattered and / or transmitted, total reflection of light incident on the optical means from the light emitting layer via the light transmitting substrate is repeated. At least a part of the light incident at such an angle (the light incident on the optical means at a wide angle (greater than the critical angle)) can be strongly scattered and / or diffracted and emitted to the outside, and furthermore, in the front direction (normal direction). ) Can be weakly scattered and / or transmitted and emitted to the outside.

[0017] The optical means may include β of light incident on the optical means from the light emitting layer via the light transmitting substrate.
At least a part of the incident light satisfying the condition of 2 ≧ 40 ° (where β2 is the inclination angle from the normal direction of the optical means) is scattered and / or diffracted and emitted outside, and β2 <40.
It is preferable that incident light that satisfies the condition of (°) is light that is weakly scattered and / or transmitted and emitted to the outside. If the optical means satisfies such a condition, of the light incident on the optical means from the light-emitting layer through the light-transmitting substrate, light incident at an angle such that total reflection is repeated (wide-angle (critical At least a portion of the light incident on the optical substrate at an angle greater than or equal to the angle) can be strongly scattered and / or diffracted and emitted to the outside. It can be emitted.

Further, the E of the present invention having any one of the above constructions
In the L device, the refractive index m1 of the light transmitting substrate
And the refractive index m2 of the optical means may be the same or substantially equal. Further, in the EL device of the present invention having any one of the above structures, the refractive index m1 of the light transmitting substrate and the refractive index m2 of the optical unit are m1 ≦ m.
Satisfying the relationship 2 is that light emitted from the light-emitting layer incident on the light-transmitting substrate is not totally reflected, and light emitted from the light-emitting layer can be efficiently extracted (emitted) to the outside. preferable.

The E of the present invention having any one of the above structures
In the L device, the optical unit may be configured such that, of the light from the light emitting layer incident on the light transmissive substrate, incident light having a critical angle or more is emitted outside with a haze of 50% or more, and incident light having a critical angle is less than 50%. The light may be emitted to the outside at a haze of 20% or less. If the optical means is such that the incident light having a critical angle or more out of the light from the light emitting layer incident on the light transmitting substrate can be emitted to the outside with a haze of 50% or more, the incident light having the critical angle or more is Scattering or the like is generated by the optical means, and the light can be emitted to the outside. Further, if the optical means can emit out of the light from the light emitting layer into the light transmissive substrate, which is less than the critical angle, out of the light with a haze of 20% or less, the incident light having the angle less than the critical angle can be used. The light can be transmitted straight (no scattering) or hardly scattered by the above-mentioned optical means and can be emitted to the outside while traveling substantially straight. Therefore, according to the EL device provided with such optical means,
Brightness in the front direction (in the normal direction and in the vicinity thereof) can be improved as compared with a conventional structure in which unevenness is provided on the surface of a scattering layer having an isotropic scattering characteristic or a transparent substrate.

The E of the present invention having any one of the above structures
In the L device, the optical means may be formed by laminating a plurality of optical films. The plurality of optical films may be stacked such that the axes at which the parallel line transmittance indicates directivity are shifted. The optical film may be a hologram.

According to another aspect of the present invention, there is provided an EL display comprising: a plurality of EL elements each including at least one organic layer including a light emitting layer and a pair of electrodes facing each other via the organic layer. Are arranged in a matrix on one surface of the light-transmitting substrate, and the EL element can be individually energized. When the EL element is energized, light emitted from the light-emitting layer emits E released to the side
An L device, wherein optical means is provided on the other surface of the light-transmitting substrate, and the optical means controls total reflection of at least a part of light from the light-emitting layer incident on the light-transmitting substrate. An EL device, which scatters and / or diffracts repeated light and emits the light to the outside, is used as an EL display, and the optical means has any one of the above structures. According to such an EL display, since the EL device of the present invention having improved brightness in the front direction is used as the EL display,
The display is bright when viewed from the front (the normal direction and its vicinity), and the display quality can be improved.
Further, since such an EL display does not require a separate lighting device, it can be made thinner than a liquid crystal display which requires a lighting device. In addition, this E
Since the light coming out to the optical means side of the L display is emitted by the light emitting layer, the display by this light emitter has a wider viewing angle than the display of the liquid crystal display. Further, the EL display has an advantage that the response speed is faster than that of the liquid crystal display.

In the EL display of the present invention having the above-mentioned structure, an EL element emitting red light, an EL element emitting green light, and an EL element emitting blue light may be used as the EL elements. With such an EL display, it is possible to provide a full-color EL display that has a bright display when viewed from the front direction (the normal direction and the vicinity thereof). In the EL display of the present invention having one of the above structures, a retardation plate (λ / 4 plate) and a polarizing plate are provided on a surface of the optical unit on a side opposite to the light transmitting substrate side. They may be provided in order from the optical means side. If the above-mentioned phase difference plate and the polarizing plate are not provided, and the former electrode of the opposing electrode and the light-transmitting electrode is formed of a reflective material such as aluminum, the ambient light Is strong (bright)
In this case, the electrode reflects ambient light, and black display cannot be visually recognized. In the EL display of the present invention, by providing the above-described retardation plate and the polarizing plate, when the ambient light is strong (bright), the ambient light is circularly polarized the first time through the retardation plate, and furthermore. This light is reflected by the electrode and emerges as circularly polarized light in the opposite direction. However, since the circularly polarized light in the opposite direction does not pass through the polarizing plate, black display can be visually recognized.

According to another aspect of the present invention, there is provided an EL lighting device comprising: at least one organic layer including a light emitting layer; and a pair of electrodes opposed to each other with the organic layer interposed therebetween. Is disposed on one surface of the light-transmitting substrate, and is capable of conducting electricity to the EL element. When the EL element is energized, light emitted from the light-emitting layer is emitted to the light-transmissive substrate side. An optical device provided on the other surface of the light-transmitting substrate, wherein the optical device is configured to totally reflect at least a part of light from the light-emitting layer incident on the light-transmitting substrate. An EL device that scatters and / or diffracts light and emits the light to the outside is used as an EL illuminating device, and the optical means has any one of the above structures. According to such an EL lighting device, the EL device of the present invention is
Since the lighting device is used as a lighting device, a device with improved brightness in the front direction can be obtained.

In the EL lighting device of the present invention having the above-described structure, the EL element is any one of an EL element that emits red light, an EL element that emits green light, an EL element that emits blue light, and an EL element that emits white light. More than one may be used. According to such an EL lighting device, the EL used
Depending on the element or the combination of the EL elements used, an EL lighting device which efficiently emits red, green, green, white or other color light and has improved luminance in the front direction can be obtained. Further, in the EL lighting device of the present invention having the above configuration, an EL element which emits blue light is used as the EL element, and between the EL element and the light transmitting substrate or between the light transmitting substrate and the optical means. Alternatively, means for converting the wavelength of light emitted in blue by the light emitting layer may be provided on the surface of the optical means. According to such an EL lighting device, it is possible to obtain an EL lighting device that efficiently emits white light and has improved luminance in the front direction.

According to another aspect of the present invention, there is provided a liquid crystal device comprising: a liquid crystal panel including a pair of substrates, a liquid crystal layer sandwiched between the substrates, and one substrate of the liquid crystal panel. And the EL illuminating device of the present invention having the above configuration provided on the side opposite to the liquid crystal layer. The liquid crystal panel may be one in which a transflective layer is provided on the liquid crystal layer side of one of the substrates. According to such a liquid crystal device, since the EL lighting device of the present invention having improved luminance in the front direction is provided, a bright display can be obtained and the display quality can be improved.

According to another aspect of the present invention, there is provided an electronic apparatus including, as a display unit, the liquid crystal device of the present invention having the above-described EL display or the above-configured EL lighting device. It is characterized by. Such an electronic device can obtain a bright display, and can provide excellent display quality by being provided with the EL display of the present invention or the liquid crystal device provided with the EL lighting device of the present invention in which the display quality is improved. An electronic device including a display unit can be provided.

[0027]

Embodiments of the present invention will be described below with reference to the drawings. (Embodiment of EL Display) FIG. 1 shows an EL display of the present invention.
FIG. 2 is a diagram illustrating an example of an embodiment in which the device is applied to an EL display, and is a plan view as viewed from a substrate side. FIG.
FIG. 2 is a schematic sectional view showing a part of the EL display shown in FIG. 1, and is a sectional view taken along the line AA ′ of FIG. FIG.
FIG. 2 is a diagram illustrating a main part of the EL display illustrated in FIG. 1, and is a schematic enlarged cross-sectional view illustrating one EL element of a plurality of EL elements provided in the EL display and a peripheral portion thereof. .

In FIGS. 1 and 2, reference numeral 1 denotes a light transmitting substrate made of glass or the like. On one surface of the light-transmitting substrate 1, a light-emitting layer 4 is interposed between a pair of electrodes 2 and 5 facing each other, and a plurality of EL elements 10 emitting any one of red, green and blue colors is emitted. Are arranged in a matrix, and the electrodes 2 and the metal electrodes 5 provided in a grid shape so as to intersect each other can be individually energized. The electrode 2 located on the light-transmitting substrate 1 side of the pair of electrodes 2 and 5 is a light-transmitting electrode. Also, a plurality of E
Around each of the L elements 10, a partition wall 8 made of a resin black resist or the like and separating adjacent EL elements 10 is provided. In the EL display shown in FIG. 1 and FIG.
The EL element shown by means that the light emitting layer 4R emits red light.
The EL element indicated by reference numeral 12 has a light emitting layer 4G emitting green light, and the EL element indicated by reference numeral 13 has a light emitting layer 4B emitting blue light. Further, the optical unit 20 is provided on the other surface of the light transmitting substrate 1 (the surface opposite to the side on which the plurality of EL elements 10 are provided). The optical means 20 scatters and / or diffracts the light that is repeatedly totally reflected out of the light from each light emitting layer incident on the light transmitting substrate 1 and emits it to the outside, and weakly scatters and / or transmits other light. And is emitted to the outside. The configuration and operation of the optical unit 20 will be described later in detail. Further, as shown in FIG. 2, a retardation plate (λ / 4 plate) 41 and a polarizing plate 42 are provided on the surface of the optical unit 20 opposite to the light transmitting substrate 1 side.
They are provided in order from the side. In FIG. 1, the phase difference plate (λ / 4 plate) 41 and the polarizing plate 42 are not shown.

As shown in FIG. 2, an EL element 12 that emits green light is formed on an indium tin oxide (In)
dium Tin Oxide, hereinafter abbreviated as ITO. A) a light-transmissive electrode 2G made of a film, a hole-transporting layer 3 for easily injecting holes from the light-transmissive electrode 2G, a light-emitting layer 4G made of an EL material, and a metal electrode 5 laminated in this order. And
The light transmissive electrode 2G and the metal electrode 5 face each other via the light emitting layer 4G. In the EL element 12 shown in FIG. 2, the light transmitting electrode 2G functions as an anode, and the metal electrode 5 functions as a cathode. Then, a predetermined current is applied to the light transmissive electrode 2G and the metal electrode 5 to cause the light emitting layer 4G to emit green light, and the green light from the light emitting layer 4G passes through the light transmissive electrode 2G to transmit light. The light enters the substrate 1. The light from the light-emitting layer incident on the light-transmitting substrate 1 reaches the optical means 20 and is acted on by the optical means 20 in accordance with the angle of incidence when the light is incident on the light-transmitting substrate 1 and is directed to the phase difference plate 41 side. The light is further emitted, passes through the phase difference plate 41 and the polarizing plate 42, and is emitted toward the outside of the EL display from below in FIG. The operation of the optical unit 20 will be described later in detail.

In the EL element 12 shown in FIG. 2, the light transmitting electrode 2G has a thickness of 150 ± 20 nm. As the hole transport layer 3, for example, 4,4′-bis (m-tolylphenylamino) biphenyl (TPD),
4,4'-bis [N- (1-naphthyl) -N-phenylamino] biphenyl (α-NPD), 4,4 ', 4 "tris [N- (3-methylphenyl) -N-phenylamino] triphenylamine (m-MTDATA ) And those using materials used in conventional hole transport layers, such as polyvinyl carbazole and polyethylene dioxythiophene. In addition, as the material used for the hole transport layer 3, one or more kinds can be used.

The light-emitting layer 4G can be made of an organic El material (electroluminescence material) that can emit green light and is used in a conventional light-emitting layer. It is made of an organic El material. In addition, the light emitting layer 4G
One or more kinds of materials can be used. Examples of the metal electrode 5 include those using materials used for conventional metal electrodes, such as aluminum, silver, silver alloy, and magnesium.

The EL element 11 that emits red light and the EL element 13 that emits blue light have the green light emission E shown in FIG.
The thickness of the L element 12 and the light transmitting electrode 2 and the material used for the light emitting layer 4 are different. In the EL element 11 emitting red light, the thickness of the light transmitting electrode 2R is 180
± 20 nm. Further, as the light emitting layer 4R,
It can be made of an organic El material used for a conventional light emitting layer and capable of emitting red light, and is preferably made of an organic El material such as rhodamine and its derivatives. In addition, as the material used for the light emitting layer 4R, one or more kinds can be used.

In the EL element 13 that emits blue light, the thickness of the light transmitting electrode 2B is 120 ± 20 nm. Further, the light emitting layer 4B can be made of an organic El material capable of obtaining blue light emission used in the conventional light emitting layer, and is preferably distyrylbiphenyl and its derivative, coumarin and its derivative, Organic El such as tetraphenylbutadiene and its derivatives
It is made of material. In addition, as the material used for the light emitting layer 4B, one or more kinds can be used.

Next, the configuration and operation of the optical means 20 provided in the EL display of this embodiment will be described in detail. As shown in FIGS. 2 and 3, the optical unit 20 includes the light emitting layer 4 (the light emitting layer 4) incident on the light transmitting substrate 1.
R, 4G, and 4B) scatter and / or diffract the light L1 that repeats total reflection of at least a part of the light, and emits the light L1 to the outside (in the case of the present embodiment, the retardation plate 41 side) to obtain other light. L3 is weakly scattered and / or transmitted and emitted to the outside (in the case of the present embodiment, to the phase difference plate 41 side). In this EL display, when a pair of electrodes 2 and 5 are energized, light emitted from the light-emitting layer 4 is emitted to the light-transmitting substrate 11 and enters the light-transmitting substrate 11. Light L1 (light incident on the light transmissive substrate 11 at a wide angle (critical angle or more)) incident at an angle that repeats total reflection of at least a part of the incident light from the light emitting layer 4 reaches the optical unit 20. The scattered light and / or diffracted light L2 is scattered and / or diffracted by the optical means 20 and emitted to the phase difference plate 41 side.
1. The light is emitted from the lower side in FIG. On the other hand, other light L3 (light incident on the light-transmitting substrate 11 at a narrow angle (less than the critical angle)) from the light-emitting layer 4 incident on the light-transmitting substrate 11 also reaches the optical unit 20, and this light The light is weakly scattered and / or transmitted by the means 20 and is emitted to the phase difference plate 41 side, and the weakly scattered light and / or the transmitted light L4 passes through the phase difference plate 41 and the polarizing plate 42 and from below in FIG. The light is emitted toward the outside of the EL display.

As a specific example of such an optical means 20, at least a part of the incident light L1 out of the light from each light emitting layer 4 incident on the light transmissive substrate 1 and having a critical angle or more is strong. The incident light L that is scattered and emitted to the outside and is smaller than the critical angle
Numeral 3 may be weakly scattered or transmitted and emitted to the outside. FIG. 4 is a diagram schematically showing the operation of the optical means 20 with respect to the light emitted from a certain point light source O. A region within a circle indicated by reference numeral 20b in FIG.
Denotes a region where the incident light incident on the light transmitting substrate 1 is smaller than the critical angle, a region outside the circle indicated by the reference numeral 20a (including the circumference).
Is a region where the incident light incident on the light transmitting substrate 1 shows a critical angle or more. As shown in FIG. 4, the optical unit 20 includes a region 20 of the light emitted from the point light source O that shows a critical angle or more.
The light incident through the point a has the effect of being strongly scattered and emitted to the opposite side of the point light source O, and the light incident through the region 20b having a smaller than the critical angle out of the light emitted from the point light source O is weak. There is an action of scattering or transmitting and emitting the light to the side opposite to the point light source O. Therefore, the optical means 20 is provided on the light transmitting substrate 1.
The incident light L1 having a critical angle or more out of the light emitted from the light emitting layer 4 is strongly scattered and can be emitted to the outside, and the incident light L3 having a critical angle is weakly scattered or transmitted (no scattering). That is, the light L3 emitted almost straight in the front direction (the normal direction and its vicinity) can be avoided, that is, the total reflection condition can be avoided.
Is not scattered or transmitted as much as possible, so that the brightness in the front direction can be improved.

Further, as another specific example of the optical means 20, at least a part of the incident light L 1 of the incident light having a critical angle or more out of the light from the light emitting layer 4 incident on the light transmitting substrate 1.
May be diffracted and emitted to the outside, and the incident light L3 smaller than the critical angle may be transmitted and emitted to the outside. FIG. 5 is a diagram schematically showing the operation of the optical means 20 with respect to light emitted from a point light source O. A region within a circle indicated by reference numeral 20b in FIG. 5 (not including the circumference). Is a region where the incident light incident on the light transmitting substrate 1 is smaller than the critical angle, and a region outside the circle indicated by reference numeral 20a (including on the circumference) is where the incident light incident on the light transmitting substrate 1 is the critical angle or more. Area. As shown in FIG. 5, the optical means 20 has a function of diffracting light incident through the region 20a having a critical angle or more out of the light emitted from the point light source O and emitting the light to the opposite side to the point light source O. ,
Of the light emitted from the point light source O, the light incident through the region 20b showing less than the critical angle is transmitted as it is and the point light source O
Has the effect of emitting light to the opposite side. Therefore, in the optical means 20, at least a part of the incident light L1 of the incident light having a critical angle or more out of the light from the light emitting layer 4 incident on the light transmitting substrate 1 can be diffracted and emitted to the outside. , The incident light L3 having a angle smaller than the critical angle can be transmitted and emitted to the outside, that is, the light L3 emitted almost straight in the front direction (the normal direction and the vicinity thereof) while avoiding the condition of total reflection. Can be transmitted, so that the luminance in the front direction can be improved.

Further, as another specific example of the optical means 20, at least a part of the incident light L 1 of the incident light having a critical angle or more out of the light from the light emitting layer 4 incident on the light transmitting substrate 1.
May be strongly scattered and diffracted and emitted to the outside, and the incident light L3 having a critical angle less than the critical angle may be weakly scattered and / or transmitted and emitted to the outside. It has both functions described with reference to FIG. Therefore, the optical means 20 strongly scatters and diffracts at least part of the incident light L1 of the incident light having a critical angle or more out of the light from the light emitting layer 4 incident on the light transmissive substrate 1 and emits it to the outside. Incident light L3 less than the critical angle
Can be weakly scattered and / or transmitted and emitted to the outside, that is, the total reflection condition can be avoided, and the light L3 emitted almost straight in the front direction (normal direction and its vicinity direction) is scattered as much as possible. Does not occur and / or can be transmitted, so that the luminance in the front direction can be improved.

Another specific example of the optical means 20 is a condition (β1 ≧ sin ⁻¹ (1 / m1)) among the light from the light emitting layer 4 incident on the light transmitting substrate 1. β1
Is a tilt angle of the light transmitting substrate 1 from the normal direction H, 1 is a refractive index of air, and m1 is a refractive index of the light transmitting substrate 1. At least a part of the incident light satisfying the condition (1) is scattered and / or diffracted and emitted to the outside, and the incident light satisfying the condition of β1 <sin ^-1 (1 / m1) is weakly scattered and / or transmitted and emitted to the outside. May be used. The value of the inclination angle β1 from the normal direction H of the light transmitting substrate 1 when the light incident on the light transmitting substrate 1 shows a critical angle or more can be calculated from Snell's law (n1 sin θ1 = n2 sin θ2),
n1 = m1, since the refractive index of air is 1, n2 = 1,
θ1 = β1, since the angle θ2 from the normal direction H of the light transmitting substrate 1 when the transmitted light when the incident light is at the critical angle is parallel to the surface of the light transmitting substrate 1 is 90 °, β1
≧ sin ⁻¹ (1 / m1).

Accordingly, the optical means 20 generates β1 ≧ sin of the light from the light-emitting layer 4 incident on the light-transmitting substrate 1.
^At least a part of incident light satisfying the condition of ^-1 (1 / m1) can be scattered and / or diffracted, and β1 <sin ^-1
The incident light satisfying the condition (1 / m1) is weakly scattered and / or
Alternatively, if the light L1 can be transmitted, at least a part of the light L1 (wide angle (equal to or greater than the critical angle) out of the light from the light emitting layer 4 incident on the light transmissive substrate 1 and incident at an angle such that total reflection is repeated. ) Can scatter and / or diffract out at least a part of the light incident on the light-transmitting substrate 1 and emit it to the outside. In addition, other light L3 (light transmission at a narrow angle (less than the critical angle)) (Light incident on the conductive substrate 1) can be weakly scattered and / or transmitted and emitted to the outside.

However, as shown in FIG. 11, the optical means 20 changes the transient state when the light incident thereon exhibits strong scattering and / or diffraction and weak scattering and / or transmission as shown in FIG. Since there is a range of about °, the optical means 20 is optimized by scattering and / or diffracting incident light having an angle of about 10 ° from the critical angle of the incident light incident on the light transmitting substrate 1. Is preferred. In FIG. 11, the horizontal axis is the rotation angle (tilt angle) of the optical unit 20, and the vertical axis is the parallel line transmittance (T%). The parallel line transmittance here is measured as shown in FIG. At the time of measurement here, incident light from a light source (light from a light emitting layer) K is incident from the right side of the optical means 20 toward the origin O1 at the center of the optical means 20, and
A measurement system is used in which a light receiving unit J such as an optical sensor receives transmitted light that passes through the optical unit 20 and travels straight through the origin O1 of the optical unit 20. At the time of measurement, the optical means 20 is rotated (tilted) so that the light source K is rotated at each rotation angle (tilt angle).
Incident on the optical means 20, the optical means 20
The light transmitted through the origin O1 and travels straight is received by the light receiving unit J and measured. The position at 0 ° in FIG. 7 is a position where the optical unit 20 is disposed horizontally (parallel) with respect to the light source K, and the clockwise angle from the 0 ° position is +, and the counterclockwise angle is −. .

Then, incident light L emitted from a light source K provided on one surface side of the optical means 20 (the left side in FIGS. 7 and 8) passes through the optical means 20 and the other surface side of the optical means 20 (FIG. 7 and 8), the optical means 20
Light scattered on one side (left side) of the
, And light transmitted through the optical means 20 is referred to as forward scattered light. With respect to the forward scattered light transmitted through the optical unit 20, the light intensity of the forward scattered light (parallel ray transmitted light) L5 which travels straight in the same direction with an angle error of ± 2 ° or less with respect to the traveling direction of the incident light L, The ratio of the incident light L to the light intensity is defined as the parallel line transmittance T, and the forward scattered light (diffuse transmitted light) LT that obliquely diffuses to the surrounding side beyond ± 2 °.
As for the light intensity, the ratio of the incident light L to the light intensity was defined as the diffuse transmittance, and the ratio of the entire transmitted light to the incident light was defined as the total light transmittance. From the above definition, a value obtained by subtracting the diffuse transmittance from the total light transmittance can be defined as the parallel line transmittance T.

Therefore, in FIG. 7, the angle at which the parallel-line transmittance T shows a low value has a large amount of scattered light (strong scattering), and the angle at which the parallel-line transmittance T has a high value shows little scattering (weak scattering) and / or Indicates that the transmitted light (parallel ray transmitted light) is large, and the scattering is small (weak scattering) from the state where the scattered light is large (strong scattering).
And / or a transient state of about 10 ° to 20 ° when the transmitted light (parallel ray transmitted light) indicates a large amount. Therefore,
The optical means 20 includes the light emitting layer 4 incident on the light transmitting substrate 1.
(1) where β1 ≧ sin ⁻¹ (1 / m1) −10 ° (where β1 is the normal direction H of the light transmitting substrate 1)
, 1 is the refractive index of air, and m1 is the refractive index of the light transmitting substrate 1. ) Is scattered and / or diffracted and exits outside, and β1
It is preferable that incident light satisfying the condition of <sin ⁻¹ (1 / m1) −10 ° be weakly scattered and / or transmitted and emitted to the outside.

Another specific example of the optical means 20 is a condition that β1 ≧ 40 ° among the light from the light emitting layer 4 incident on the light transmitting substrate 1 (where β1 is the light transmitting substrate 1).
At least a portion of the incident light satisfying the inclination angle from the normal line direction) is strongly scattered and / or diffracted and exits outside, and β
Incident light satisfying the condition of 1 = 0 may be weakly scattered and / or transmitted and emitted to the outside. To determine a specific value (approximate value) of the inclination angle β1 from the normal direction H of the light-transmitting substrate 1 when the light incident on the light-transmitting substrate 1 has a critical angle or more, the light-transmitting substrate 1 As 1, a transparent resin such as a glass substrate (refractive index: about 1.54) or an acrylic resin (refractive index: about 1.49) can be used, and these refractive indexes are 1.49 to 1.6 (n1). = 1.49-1.
6), the method of the light transmitting substrate 1 when the transmitted light when the refractive index of air is 1 (n2 = 1) and the incident light is at a critical angle becomes parallel to the surface of the light transmitting substrate 1 Since the angle θ2 from the linear direction H is 90 °, θ1 is about 40 ° according to Snell's law described above, and the critical angle β1 of the light incident on the light-transmitting substrate 1 is about 40 °. . When a glass substrate (refractive index: about 1.54) is used as the light transmissive substrate 1, the critical angle β1 is 40.5 °. Therefore, the optical unit 20 can strongly scatter and / or diffract at least a part of the incident light satisfying the condition of β1 ≧ 40 ° among the light from the light emitting layer 4 incident on the light transmitting substrate 1,
If the incident light satisfying the condition of β1 = 0 can be weakly scattered and / or transmitted, it is incident at an angle such that total reflection of light from the light emitting layer 4 incident on the light transmitting substrate 1 is repeated. It is possible to strongly scatter and / or diffract at least a part of the light L1 (at least a part of the light incident on the light transmissive substrate 1 at a wide angle (critical angle) or more) out of the light. In addition, the light L3 emitted straight in the front direction (normal direction) is weakly scattered and / or
Alternatively, the light can be transmitted and emitted to the outside.

In addition, the optical means 20 performs the condition that β1 ≧ 40 ° in the light from the light emitting layer 4 incident on the light transmitting substrate 1 (where β1 is the normal direction of the light transmitting substrate 1). At least a part of the incident light satisfying the condition (β1 <40 °) is weakly scattered and / or transmitted and emitted to the outside. It is preferable that Optical means 20
Satisfies such a condition, at least a part of the light L1 out of the light incident from the light emitting layer 4 into the light transmissive substrate 1 at an angle such that total reflection is repeated. (Light incident on the light transmissive substrate 1 at a wide angle (not less than the critical angle)) can be strongly scattered and / or diffracted and almost emitted to the outside, and the incident light L3 having a less than the critical angle is weakly scattered and / or transmitted. And it can be almost emitted to the outside.

Another specific example of the optical means 20 is as follows.
The condition β2 ≧ sin ⁻¹ (1 / m2) of the light incident on 0 (where β2 is the inclination angle of the optical means 20 from the normal direction H, 1 is the refractive index of air, and m2 is the optical means At least a portion of the incident light that satisfies the refractive index).
Or, diffracted and emitted to the outside, β2 <sin ⁻¹ (1 / m
2) The incident light that satisfies the condition may be light that is weakly scattered and / or transmitted and emitted to the outside. The value of the inclination angle β2 from the normal direction H of the optical means 20 when the light incident on the optical means 20 indicates a critical angle or more can be calculated from the above Snell's law (n1sinθ1 = n2sinθ2, n1 = m2, Since the refractive index of air is 1, n2
= 1, θ1 = β2, and the angle θ2 from the normal direction of the light transmitting substrate 1 when the transmitted light is parallel to the surface of the light transmitting substrate 1 when the incident light is at a critical angle is 90 ° From
β2 ≧ sin ⁻¹ (1 / m2) can be calculated. Therefore,
The above-mentioned optical means 20 transmits β2 ≧ sin of light incident on the optical means 20 from the light-emitting layer 4 via the light-transmitting substrate 1.
^At least part of the incident light satisfying the condition of ^-1 (1 / m2) can be scattered and / or diffracted, and β2 <sin ^-1 (1
/ M2) as long as the incident light that satisfies the condition of the following can be weakly scattered and / or transmitted: an angle at which total reflection of light incident on the optical means 20 from the light emitting layer 4 through the light transmitting substrate 1 is repeated. At least a part of the light L1 (light incident on the optical means at a wide angle (not less than the critical angle))
Can be scattered and / or diffracted and emitted to the outside, and other light L3 (light incident on the optical means at a narrow angle (less than the critical angle)) is weakly scattered and / or transmitted and emitted to the outside. be able to.

Further, as described above, the incident light incident on the optical means 20 from the light-emitting layer 4 via the light transmitting substrate 1 exhibits strong scattering and / or diffraction by the optical means 20, and exhibits weak scattering. Since the transient state of the angle at this time has a range of about 10 ° to about 20 °, the incident light having an angle shifted by about 10 ° from the critical angle of the incident light that has entered the optical means 20 through the light transmitting substrate 1. Preferably, the optical means 20 is optimized so that it can also scatter and / or diffract. Therefore, the optical means 20 determines that β2 ≧≧ 2
sin ⁻¹ (1 / m2) −10 ° (where β2 is the inclination angle of the optical means 20 from the normal direction H, 1 is the refractive index of air, and m2 is the refractive index of the optical means 20. ) Is scattered and / or diffracted and emitted to the outside, and the incident light that satisfies the condition of β2 <sin ⁻¹ (1 / m2) −10 ° is weakly scattered and / or transmitted. It is preferable that the light is emitted to the outside.

As another specific example of the optical means 20, the light emitting layer 4 passes through the light-transmitting substrate 1 and the optical means 20.
Condition that β2 ≧ 40 ° among the light incident on
At least a part of the incident light satisfying the inclination angle from the normal direction H of the optical means 20 is strongly scattered and / or diffracted and emitted to the outside, and the incident light satisfying the condition β2 = 0 ° is weakly scattered The light may be transmitted and emitted to the outside. The specific value (approximate value) of the inclination angle β2 from the normal direction H of the optical means 20 when the light incident on the optical means 20 from the light emitting layer 4 via the light transmitting substrate 1 shows a critical angle or more. To determine, the average refractive index in the optical means 20 is about 1.57 (n1 = 1.5
7), the refractive index of air is 1 (n2 = 1), and the normal direction H of the optical means 20 when the transmitted light is parallel to the surface of the optical means 20 when the incident light is at a critical angle. Is 90 °, the angle θ1 is about 40 ° according to Snell's law, and the critical angle β2 of the light incident on the optical means 20 is 39.6 °. 40 °. Therefore, the optical means 20 performs strong scattering and / or diffraction of at least a part of the incident light that satisfies the condition of β2 ≧ 40 ° among the light incident on the optical means 20 from the light emitting layer 4 via the light transmitting substrate 1. If the incident light that satisfies the condition of β2 = 0 can be weakly scattered and / or transmitted, total reflection of light incident on the optical means 20 from the light emitting layer 4 via the light transmitting substrate 1 is repeated. Light at a wide angle (wide angle (above the critical angle)
At least a part of the light incident on the light source (0) can be strongly scattered and / or diffracted and emitted to the outside, and the light emitted straight in the front direction (normal direction) is weakly scattered and / or transmitted. Light to the outside.

Further, the optical means 20 has a condition that β2 ≧ 40 ° among the light incident on the optical means 20 from the light emitting layer 4 via the light transmitting substrate 1 (where β2 is a normal line of the optical means 20). (Inclination angle from the direction H) is scattered and / or diffracted and emitted to the outside, and β2
It is preferable that the incident light satisfying the condition of <40 ° be emitted to the outside after being weakly scattered and / or transmitted.
If the optical means 20 satisfies such conditions,
From the light emitting layer 4 through the light transmitting substrate 1, the optical means 20
At least part of light L1 (light incident on the optical substrate at a wide angle (greater than the critical angle)) incident at an angle such that total reflection is repeated out of the light incident on the substrate is strongly scattered and / or diffracted and almost emitted to the outside The incident light L3 having a critical angle less than the critical angle can be weakly scattered and / or transmitted and almost emitted to the outside.

In the present invention, the term "scattering" means that incident light incident on a light-transmitting substrate or an optical means at a wide angle (a critical angle or more) is incident light of forward scattered light transmitted through the light-transmitting substrate or the optical means. In the same direction with forward scattered light (diffuse transmitted light) that diffuses obliquely to the surrounding side exceeding ± 2 ° with respect to the traveling direction of the incident light and within ± 2 ° with respect to the traveling direction of the incident light Forward scattered light traveling straight (parallel transmitted light)
Both or one is included. The strong scattering is a case where the haze value is 50% or more, and the weak scattering is a case where the haze value is 20% or less. Diffraction is a phenomenon in which incident light incident at a wide angle (greater than or equal to a critical angle) bends the traveling direction of outgoing light with respect to the traveling direction of incident light in transmitted light transmitted through a light-transmitting substrate or optical means. That is. Transmission is defined as an angle error within ± 2 ° with respect to the traveling direction of the incident light of the forward scattered light transmitted through the light-transmitting substrate or the optical means when the incident light incident at a narrow angle (less than the critical angle). It refers to forward scattered light (parallel transmitted light) that travels straight in the same direction.

As described above, the refractive index m1 of the light transmitting substrate 1
Is 1.49 to 1.6, the refractive index m2 of the optical means 20 is about 1.57 (average refractive index), and the refractive index m1 of the light transmitting substrate 1 and the refractive index m2 of the optical means 20 are They are the same size or approximately the same size. The refractive index m1 of the light transmitting substrate 1 and the refractive index m2 of the optical unit 20 are:
Preferably, the relationship of m1 ≦ m2 is satisfied so that light from the light-emitting layer 4 incident on the light-transmitting substrate 1 is not totally reflected, and light emitted from the light-emitting layer 4 is efficiently taken out (emitted). ) Is preferable.

In addition, the optical means 20 outputs the incident light having a critical angle or more out of the light from the light emitting layer 4 into the light transmitting substrate 1 with a haze of 50% or more and the incident light having a haze of less than the critical angle. May emit to the outside with a haze of 20% or less. The haze here is a transmittance scale called haze in the field of optics, and is a value obtained by dividing the diffuse transmittance described with reference to FIG. This is a definition of a concept completely different from the parallel line transmittance. The larger the haze value, the stronger (more) the forward scattered light (diffuse transmitted light), and the smaller the haze value, the stronger (more) the parallel light transmitted light. As long as the optical means 20 can emit the light having a critical angle or more out of the light from the light emitting layer 4 into the light transmitting substrate 1 with a haze of 50% or more, the incident light having the critical angle or more can be obtained. Can be scattered by the optical means 20 and emitted to the outside. In addition, if the optical means 20 can emit out of the light from the light-emitting layer 4 into the light-transmitting substrate 1 with a haze of 20% or less out of the light from the light-emitting layer 4, the haze is less than the critical angle. The incident light can be transmitted straight (without scattering) or hardly scattered by the above-mentioned optical means and can be emitted to the outside while traveling substantially straight. Therefore, when such an optical unit 20 is provided, the conventional one that exhibits the same scattering characteristics in all incident directions, in other words,
Brightness in the front direction (in the normal direction and in the vicinity thereof) can be improved as compared with a conventional structure in which unevenness is provided on the surface of a scattering layer having an isotropic scattering characteristic or a transparent substrate.

The optical means 20 used in this embodiment will be described more specifically. The optical means 20 has optical characteristics as shown by the curve in FIG. 6, for example. In FIG. 6, the horizontal axis represents the rotation angle (inclination angle) of the optical unit 20, and the vertical axis represents the parallel line transmittance (T%). The optical characteristics here were measured in the same manner using the measurement system shown in FIG. The optical means 20 having such optical characteristics can be obtained by laminating a plurality of optical films. Each of the above optical films is disclosed in JP-A-2000-0355 from the viewpoint of the basic structure.
06, JP-A-2000-0666026, JP-A-2000-1
A forward scattering film having directivity disclosed in 80607 and the like can be used as appropriate. For example, JP
As disclosed in 00-035356, a resin sheet, which is a mixture of two or more types of photopolymerizable monomers or oligomers having mutually different refractive indices, is irradiated with an ultraviolet ray from an oblique direction so that only a specific wide direction is irradiated. One having a function of scattering efficiently, or JP-A-2000-06
As the on-line holographic diffusion sheet disclosed in No. 6026, a material obtained by irradiating a hologram photosensitive material with a laser so that regions having partially different refractive indices have a layer structure can be appropriately used. FIG.
FIG. 3 is a schematic diagram showing an example of a cross-sectional structure of an optical film 21 manufactured by the hologram technique as described above. The optical film 21 has a refractive index of n1 and a refractive index of n2.
Are arranged alternately in layers in a diagonal direction at a predetermined angle in the cross-sectional structure of the optical film 21. Assuming that the incident light L1 is incident on the optical film 21 having this structure at a wide angle (not less than the critical angle) from an oblique direction, the light is scattered and / or diffracted at the boundary between the layers having different refractive indices, and these lights are on the opposite side ( In the drawing, the light is emitted as scattered light and / or diffracted light L2 to the lower surface side. Also, the optical film 2 having this structure
1. The incident light L3 at a narrow angle (less than the critical angle) from an oblique direction
Is weakly scattered and / or transmitted at the boundary between layers having different refractive indices, and these lights are emitted to the opposite side (lower side in the drawing) as weakly scattered light and / or transmitted light L4. It has become.

The optical characteristics of the optical film 21 produced by the hologram technique described above have, for example, the optical characteristics shown by the curve in FIG. The optical characteristics here were measured in the same manner using the measurement system shown in FIG. The optical characteristics as shown by the curve in FIG.
This is a characteristic in the AB direction of the optical film 21 in FIG. 9, and the AB direction is the axis α at which the parallel line transmittance indicates directivity. Therefore, in order to obtain the optical means 20 having the optical characteristics as shown by the curve in the figure from the optical film 21 having such optical characteristics, a plurality of optical films 21 are prepared, and the parallel line transmittance indicates directivity. The lamination may be performed by shifting the axis α. Specifically, as shown in FIG. 10, two optical films 21 are prepared, and the lamination is performed by shifting the axis α at which the parallel line transmittance indicates directivity by 180 °. Can be

In the EL display of this embodiment, the optical means 20 having the above-described structure is provided on the other surface of the light-transmitting substrate 1, so that the light-emitting layer 4 incident on the light-transmitting substrate 1 is provided. Light L1 (light incident on the light-transmitting substrate 1 at a wide angle (greater than or equal to the critical angle)) which is incident at an angle such that total reflection of at least a part of light from the light is repeated, and / or diffracted. 41, and further scattered light and / or diffracted light L2
The light can be emitted to the outside through the polarizing plate 42,
In addition, the other light L3 (light incident on the light transmissive substrate 1 at a narrow angle (less than the critical angle)) is weakly scattered and / or transmitted and emitted to the retardation plate 41 side, and further the weakly scattered light and / or Since the transmitted light L4 can be emitted to the outside by passing through the retardation plate 41 and the polarizing plate 42, it can be compared with a conventional light scattering layer having an isotropic scattering characteristic or a transparent substrate provided with irregularities on the surface thereof. Front direction (normal direction and its vicinity)
Brightness can be improved. That is, in the EL display of the present embodiment, at least a part of the light L1 out of the light incident on the light transmissive substrate 1 at a wide angle (critical angle or more) is scattered and / or diffracted, and a narrow angle (critical angle) is obtained. The optical means 20 that can have no effect or have a weak effect on the light L3 incident on the light-transmitting substrate 1 in E
By providing the light transmitting substrate 1 on the surface of the light transmitting substrate 1 as a support substrate of the L element 10, it is possible to avoid the condition of total reflection and to reduce the light emitted almost straight in the front direction (the normal direction H and its vicinity). The light emitted from the light emitting layer 4 is efficiently extracted (emitted) to the outside so as not to be scattered, whereby the brightness in the front direction can be improved. Therefore, according to the EL display of the present embodiment, since the brightness in the front direction is improved, the display when viewed from the front direction (the normal direction and the vicinity thereof) is bright, and the display quality is improved. Can be. Further, since such an EL display does not require a separate lighting device, it can be made thinner than a liquid crystal display which requires a lighting device. Also, since the light coming out to the optical means 20 side of the EL display is emitted by the light emitting layer, the display by this light emitter has a wider viewing angle than the display of the liquid crystal display. Further, the EL display has an advantage that the response speed is faster than that of the liquid crystal display.

Further, in the EL display of this embodiment, since the EL element 10 includes the EL element 11 that emits red light, the EL element 12 that emits green light, and the EL element 13 that emits blue light, The display is bright when viewed from the front direction (the normal direction and the vicinity thereof), and a full-color EL display can be provided. In the EL display according to the present embodiment,
A retardation plate (λ / 4 plate) 41 and a polarizing plate 42 are provided on the surface of the optical unit 20 opposite to the light transmitting substrate side.
Since the ambient light is provided in order from the 0 side, when the ambient light is strong (bright), the ambient light is circularly polarized when passing through the retardation plate 41 for the first time. The circularly polarized light of the opposite direction is reflected by the polarizing plate 42.
, The black display can be visually recognized.

In the EL display of this embodiment, the light transmitting electrode 2R of the EL element 11 that emits red light is used.
And the light transmitting electrode 2 of the EL element 12 that emits green light
The thickness of G and the thickness of the light-transmitting electrode 2B of the EL element 13 that emits blue light are different from the thickness of the EL element 11 that emits red light and the EL element 12 that emits green light. Some of the EL elements 13 that emit blue light may have the same light-transmitting electrode 2 thickness, or all of the light-transmitting electrodes 2 may have the same thickness. Also,
In the EL display of the present embodiment, the light transmissive electrode 2 is made of ITO, but may be made of an indium zinc oxide (hereinafter abbreviated as IZO) film. Further, an EL element 11 that emits red light,
EL element 12 emitting green light and EL element 1 emitting blue light
3 does not have to have the light transmitting electrodes 2 all made of the same material, and the light transmitting electrodes made of ITO and the light transmitting electrodes made of IZO may be mixed. In the present embodiment, as an example of the EL element 10, as shown in FIGS.
And the hole transport layer 3, the light emitting layer 4, and the metal electrode 5 have been described as an example.
The L element is not limited to this example.

(Embodiment of Liquid Crystal Device) FIG. 12 is a view showing a liquid crystal device provided with an EL illuminating device to which the EL device of the present invention is applied, and FIG. FIG. 12B is a cross-sectional view showing an example of a case where the transmission type is used. FIG. 13 is a schematic enlarged sectional view showing an EL lighting device provided in the liquid crystal device of FIG. A liquid crystal display device (liquid crystal device) as a final product is configured by attaching ancillary elements such as a liquid crystal driving IC and a support to the liquid crystal device 110 of this embodiment. A liquid crystal device 110 of this embodiment has a pair of rectangular substrate units 113 in a plan view, which are substantially rectangular in a plan view and are attached to each other with a cell gap therebetween via an annular sealing member 112 so as to face each other. 114, a liquid crystal layer 115 sandwiched between and sandwiched by the sealing material 112, and a phase difference plate 119 and a polarizing plate 1 provided on the upper surface side of one of the substrate units 113 (upper side in FIG. 12).
16, a liquid crystal panel 111 provided with a phase difference plate 156 and a polarizing plate 157 provided on the lower surface side of the other (lower side of FIG. 12) substrate unit 114, and a back provided below the liquid crystal panel 111. EL lighting device 1 as light device
The main configuration is 60.

Of the substrate units 113 and 114, the substrate unit 113 is a front (upper) substrate unit provided toward the observer, and the substrate unit 114 is provided on the opposite side, in other words, on the back side (lower side). Substrate unit. The upper substrate unit 113 includes a light-transmitting substrate 117 made of a transparent material such as glass, and a substrate 1.
A phase difference plate 119 and a polarizing plate 116 which are sequentially provided on the front side of FIG.
A color filter layer 120 and an overcoat layer 121 sequentially formed on the back side (in other words, the liquid crystal layer 115 side) of
The overcoat layer 121 includes a plurality of stripe-shaped electrode layers 123 for driving liquid crystal formed on the surface on the liquid crystal layer 115 side. The liquid crystal layer 115 is composed of nematic liquid crystal molecules having a twist angle θt of 240 to 255 degrees.

In an actual liquid crystal device, alignment films are formed on the liquid crystal layer 115 side of the electrode layer 123 and the liquid crystal layer 115 side of the stripe-shaped electrode layer 135 on the lower substrate, which will be described later. In FIG. 12, these alignment films are omitted and description thereof is omitted, and illustration and description of alignment films are also omitted in other embodiments which will be sequentially described below. Also,
The cross-sectional structure of the liquid crystal device shown in FIG.
In the case shown in the figure, the thickness of each layer is adjusted to be different from that of the actual liquid crystal device so that each layer is easy to see. In the present embodiment, the driving electrode layers 123 on the upper substrate side are I
It is formed in a stripe shape from a transparent conductive material such as TO (Indium TinOxide), and is formed in a necessary number according to the display area of the liquid crystal panel 110 and the number of pixels. The color filter layer 120
In the present embodiment, are formed by forming a black mask for blocking light and RGB patterns for color display on the lower surface of the upper substrate 117 (in other words, the surface on the liquid crystal layer 115 side). Further, the overcoat layer 121 is used as a transparent protective flattening film for protecting the RGB pattern.
Is coated. The black mask has a thickness of 100 to 200 n by, for example, a sputtering method or a vacuum evaporation method.
It is formed by patterning a metal thin film such as chrome of about m. Each of the above RGB patterns includes a red pattern (R), a green pattern (G), and a blue pattern (B).
It is arranged in a desired pattern shape, and is formed by various methods such as a pigment dispersion method using a photosensitive resin containing a predetermined coloring material, various printing methods, an electrodeposition method, a transfer method, and a dyeing method. .

On the other hand, the lower substrate unit 114 is sequentially formed on a light-transmitting substrate 128 made of a transparent material such as glass, and on the surface side of the substrate 128 (the upper surface side in FIG. 12, in other words, the liquid crystal layer 115 side). The semi-transmissive reflective layer 131, the overcoat layer 133, the plurality of driving electrode layers 135 formed in a stripe on the surface of the overcoat layer 133 on the liquid crystal layer 115 side, and the back surface side of the substrate 128 (FIG. 12). In the figure, a phase difference plate 156 and a polarizing plate 157 are sequentially formed on the lower surface side (in other words, the side opposite to the liquid crystal layer 115 side). Like the electrode layer 123, the required number of these electrode layers 135 are formed in accordance with the display area of the liquid crystal panel 110 and the number of pixels.

Next, the transflective layer 131 of this embodiment
Is made of a metal material having excellent light reflectivity and conductivity, such as Ag or Al, and is formed on the substrate 128 by an evaporation method, a sputtering method, or the like. The transflective layer 131 is a transflective layer or a part of the transflective layer having a thickness sufficient to allow light emitted from the EL lighting device 160 provided below the liquid crystal panel 111 to pass therethrough. For example, a structure widely used in a transflective liquid crystal display device such as a structure in which a number of fine through holes are formed to enhance light transmittance can be appropriately adopted. However, it is not essential that the transflective layer 131 is made of a conductive material. A driving electrode layer made of a conductive material is provided separately from the transflective layer 131, and the transflective layer 131 and the drive electrode are separately provided. A structure can be adopted.

The EL lighting device 160 is shown in FIGS.
3, an EL element 21 including a pair of electrodes 162 and 165 opposed to each other with a light emitting layer 164 interposed therebetween.
0 is disposed on one surface of the light transmitting substrate 161 and at least the light transmitting substrate 1 of the pair of electrodes 162 and 165 is disposed.
The electrode 162 located on the 61 side is formed of a light-transmitting electrode, and is capable of conducting electricity to the EL element 210. 161 side. Light transmitting electrode 162 and light emitting layer 16 of EL element 210
4, a hole transport layer 163 for easily injecting holes from the light transmitting electrode 162 is provided. The material of each layer constituting the EL element 210 can be the same as the material used for each layer constituting the EL element 10 provided in the EL display of the above-described embodiment.
In particular, the light-emitting layer 164 is preferably formed using a material that can emit white light. Also, the light transmitting substrate 1
Optical means 220 is provided on the other surface of 61 (the surface opposite to the side on which EL element 210 is provided). The optical unit 220 scatters and / or diffracts light that repeats total reflection of at least a part of the light from the light emitting layer 164 incident on the light transmitting substrate 161 and emits the light to the outside, and weakly scatters other light. And / or transmit to the outside. The optical means 220 used here is the same as the optical means 20 used in the EL display of the above-described embodiment. Such an EL lighting device 160
The optical means 220 faces the liquid crystal panel 110 side, that is, the EL illuminating device 160 is disposed below the liquid crystal panel 110 so that illumination light can be emitted from the lower side of the liquid crystal panel 110 toward the liquid crystal panel 110. It has become.

The operation of the EL lighting device 160 will be described in detail. When electricity is supplied to the pair of electrodes 162 and 165,
The light emitted from the light emitting layer 164 is emitted toward the light transmitting substrate 161 and enters the light transmitting substrate 161. The light from the light emitting layer 164 incident on the substrate 161 repeats total reflection. At least a part of light L1 (wide angle (critical angle or more)) of light incident at an angle
1) reaches the optical means 220, and is scattered and / or diffracted by the optical means 220 and
The scattered light and / or diffracted light L2 emitted to the liquid crystal panel 111 from the lower side in FIG.
Is emitted as illumination light toward. On the other hand, of the light from the light emitting layer 164 incident on the light transmitting substrate 111, another light L3 (light incident on the light transmitting substrate 164 at a narrow angle (less than the critical angle)) also reaches the optical unit 220, and Means 2
The liquid crystal panel 111 is weakly scattered and / or transmitted at 20.
And the weakly scattered light and / or transmitted light L
4 is emitted as illumination light from below to the liquid crystal panel 111 in FIG.

Here, the EL illuminating device 160 is not always lit, but is lit only when there is almost no ambient light (external light) in accordance with an instruction from a user or a sensor. Therefore, when the EL lighting device 160 is turned on, as shown in FIG.
When the EL illuminating device 160 is turned off (the ambient light is sufficiently strong), the light from the device passes through the transflective layer 131 to function as a transmissive type and perform transmissive display. As shown in FIG. 12A, the light L incident from the upper surface side of the liquid crystal panel 111 (the surface side of the polarizing plate 116) is reflected on the surface of the semi-transmissive reflective layer 131, thereby functioning as a reflective type and performing reflective display. become. EL lighting device 160 provided in the liquid crystal device of the present embodiment
Since the optical means 220 having the above-described configuration is provided on the other surface of the light-transmitting substrate 161, the luminance in the front direction (in the normal direction H and its vicinity) can be improved. According to the liquid crystal device of the present embodiment, since the EL illuminating device 160 of the present embodiment having the improved brightness in the front direction is provided, a bright display can be obtained and the display quality can be improved.

In this embodiment, a case has been described in which the EL element 210 provided in the EL lighting device 160 is provided with an EL element that emits white light.
As the L element 210, at least one of an EL element that emits red light, an EL element that emits green light, an EL element that emits blue light, and an EL element that emits white light may be used. According to such an EL lighting device, red, green, green, white, or other colors of light are efficiently emitted depending on the EL element used or the combination of EL elements used, and the luminance in the front direction is improved. , An EL lighting device. In addition, an EL element that emits blue light is used as the EL element 210, and is used between the EL element 210 and the light-transmitting substrate 161 or the light-transmitting substrate 1.
A unit for converting the wavelength of light emitted in blue by the light emitting layer 164 may be provided between the optical unit 61 and the optical unit 220 or on the surface of the optical unit 220. According to such an EL lighting device, it is possible to obtain an EL lighting device that efficiently emits white light and has improved luminance in the front direction. In the above embodiment, the case where the EL lighting device of the present embodiment is provided in the transflective liquid crystal device has been described.
A transmissive liquid crystal device may be provided. In that case, a liquid crystal panel having the same structure as the liquid crystal panel 111 shown in FIG. 12 except that the transflective layer 31 is not provided may be used. it can.

In the liquid crystal device according to the embodiment, the case where the EL illumination device of the present invention is provided in the transflective liquid crystal display device of a simple matrix type has been described. Needless to say, the present invention may be applied to an active matrix type transflective liquid crystal display device provided with a type switching element or a three-terminal type switching element. Further, in the liquid crystal device provided with the EL lighting device of the embodiment described above, the phase difference plate 119 is provided between the upper substrate 117 and the polarizing plate 116.
Although the example in which the present invention is applied to the transflective liquid crystal display device provided with one sheet has been described, the present invention may be applied to a transflective liquid crystal display device provided with a plurality of retardation plates. Of course. In the above embodiment,
An example in which the present invention is applied to a transflective liquid crystal display device in which a retardation plate and a polarizing plate are provided on the lighting device 160 side of the lower substrate 128 has been described.
Needless to say, the present invention may be applied to a transflective liquid crystal display device in which a retardation plate and a polarizing plate are not provided on the EL lighting device 160 side.

[Embodiment of Electronic Apparatus] Next, a specific example of an electronic apparatus including a liquid crystal device provided with the EL display of the above embodiment or the EL lighting device of the embodiment will be described. FIG. 14A is a perspective view illustrating an example of a mobile phone. In FIG. 14A, reference numeral 500 denotes a mobile phone main body, and reference numeral 501 denotes E of the embodiment shown in FIGS.
14 illustrates an EL display unit (display unit) including an L display or a liquid crystal device including the EL lighting device according to the embodiment illustrated in FIGS. 12 and 13. FIG. 14B is a perspective view showing an example of a portable information processing device such as a word processor or a personal computer. 14B, reference numeral 600 denotes an information processing apparatus; 601, an input unit such as a keyboard; 603, an information processing main body; 602, an EL display of the embodiment shown in FIGS. 1 to 3 or FIGS. 13 shows an EL display unit (display means) provided with a liquid crystal device provided with the EL lighting device of the embodiment shown in FIG. FIG. 14 (c)
1 is a perspective view showing an example of a wristwatch-type electronic device. In FIG. 14C, reference numeral 700 denotes a watch main body;
Shows an EL display unit (display means) including a liquid crystal device provided with the EL display of the embodiment shown in FIGS. 1 to 3 or the EL lighting device of the embodiment shown in FIGS. I have. Since the electronic devices shown in FIGS. 14A to 14C are provided with the liquid crystal device provided with the EL display of the above embodiment or the EL lighting device of the embodiment, excellent display quality can be obtained. An electronic device including a display unit can be provided.

[0068]

EXAMPLES Test Example 1 A plurality of optical films of Examples having optical characteristics as shown in FIG. 15A were produced. In FIG. 15, the horizontal axis is the rotation angle (tilt angle) of the optical film, and the vertical axis is the parallel line transmittance (T%). This FIG.
The optical characteristics shown by the curve (A) are the characteristics in the AB direction of the optical film in FIG. 15B, and the AB direction is the axis α2 at which the parallel line transmittance indicates the directivity. . The optical characteristics here were measured in the same manner using the measurement system shown in FIG. Then, an optical unit was manufactured using one to four optical films having the optical characteristics shown in FIG. When using multiple optical films,
The directivity axis α2 was shifted by 45 degrees and laminated to form optical means. When the optical means manufactured as described above was provided in the EL display shown in FIGS. 1 to 3, the front luminance of the EL display was measured. The results are shown in Table 1 below. In Table 1, the number of optical films is 0 when no optical film is provided. Also, for comparison, an EL display of a comparative example in which the surface of the transparent substrate is roughened to provide unevenness (in the conventional EL display of FIG. 18, instead of providing the scattering layer 820, the surface of the transparent substrate 801 is roughened to reduce unevenness) Provided)
Was measured for frontal luminance. The results are shown in Table 2 below.

“Table 1” Number of Optical Films of Examples 0 1 2 3 4 Front luminance (cd / m ² ) of EL display 50.1 58.1 68.9 79.2 86.9

[Table 2] Front luminance (cd / m ² ) of EL display of Comparative Example 53.4

From the results shown in Tables 1 and 2, the EL display using the optical film of the example as an optical means is comparable to the EL display of the comparative example (conventional) in which the surface of the transparent substrate is roughened to provide irregularities. It can be seen that the brightness at the front can be increased and a bright display can be obtained. Further, in an EL display using an optical unit in which a plurality of the optical films of the examples are used and the directivity axes are shifted from each other,
It can be seen that the front luminance can be increased as the number of optical films increases, and a bright display can be obtained.

"Test Example 2" A plurality of optical films of the examples having optical characteristics as shown in FIG. 17A were produced.
In FIG. 17, the horizontal axis is the rotation angle (tilt angle) of the optical film.
And the vertical axis is the parallel line transmittance (T%). This figure 1
The optical characteristic as shown by the curve in FIG.
Are the characteristics of the optical film in the AB direction.
The direction is the axis α1 at which the parallel line transmittance indicates directivity. The optical characteristics here were measured in the same manner using the measurement system shown in FIG. Then, an optical unit was manufactured using one to eight optical films having the optical characteristics shown in FIG. When a plurality of optical films were used, the optical means was formed by shifting the directivity axis α1 by 45 degrees as shown in FIG. When the optical means manufactured as described above was provided in the EL display shown in FIGS. 1 to 3, the front luminance of the EL display was measured. The results are shown in Tables 3 and 4 below. In Table 3, the number of optical films is 0 when no optical film is provided. Further, for comparison, the surface of the transparent substrate was roughened to provide irregularities, so that E
The front luminance of the L display (the conventional EL display of FIG. 18 in which the surface of the transparent substrate 801 was roughened to provide irregularities instead of providing the scattering layer 820) was measured. The results are shown in Table 5 below.

“Table 3” Number of Optical Films of Example 0 1 2 3 4 Front Luminance (cd / m ² ) of EL Display 50.1 53.2 57.9 61.5 65.8 “Table 4” Number of Optical Films of Example 5 6 7 8 Front brightness (cd / m ² ) of EL display 68.9 73.2 77.5 81.5

[Table 5] Front luminance (cd / m ² ) of EL display of Comparative Example 53.4

From the results shown in Tables 3 to 5, it can be seen that the EL display using the optical film of the example as an optical means is comparable to the EL display of the comparative example (conventional) in which the surface of the transparent substrate is roughened to provide irregularities. It can be seen that the brightness of the front can be increased and a bright display can be obtained. Further, in an EL display using an optical unit in which a plurality of the optical films of the examples are used and the directivity axes are shifted from each other,
It can be seen that the front luminance can be increased as the number of optical films increases, and a bright display can be obtained.

Test Example 3 Various optical means having different optical characteristics were produced by using a plurality of optical films produced by the hologram technique. The haze (%) above the critical angle and the haze (%) in the range below the critical angle were measured for the various prepared optical means. Here, the haze is measured by forward scattered light (diffuse transmitted light) measured using the measurement system shown in FIG.
The diffuse transmittance calculated from the light intensity of the incident light L is divided by the total light transmittance and expressed in%. Then, when the manufactured various optical means were provided in the EL display shown in FIGS. 1 to 3, the front luminance of the EL display was measured. The results are shown in Tables 6, 7, and 8 below. Table 8 shows the case where the optical means is not provided in the EL display shown in FIGS. Also, for comparison, an EL display of a comparative example in which the surface of the transparent substrate is roughened to provide irregularities (in the conventional EL display of FIG. 18, instead of providing the scattering layer 820, the surface of the transparent substrate 801 was roughened so Provided) was measured. The results are shown in Table 9 below.

[0077] "Table 6" critical angle or more ranges of haze (%) 30 40 50 60 70 80 Haze in the range of less than the critical angle (%) 5 5 5 5 5 5 EL display front luminance (cd / m ²⁾ 51.6 52.3 55.4 60.3 62.3 63.9 “Table 7” Haze in range above critical angle (%) 70 70 70 70 70 70 Haze in range below critical angle (%) 5 10 15 20 25 30 Front luminance of EL display (cd / ^{m 2) 62.3 62.1 61.4 60.5 56.9} 53.1 "Table 8" number of optical means 0 EL display front luminance (cd / m ²⁾ 50.1

“Table 9” Front luminance (cd / m ² ) of EL display of comparative example 53.4

From the results shown in Tables 6 to 9, the EL display provided with the optical means having a haze of 50% or more in the range equal to or more than the critical angle is the EL display without the optical means.
It can be seen that the brightness of the front can be increased as compared with the display (Table 8) and the EL display of the comparative example (conventional) in which the surface of the transparent substrate is roughened to provide unevenness. Also, it can be seen that the EL display provided with the optical means having a haze of 60% or more, particularly in the range of the critical angle or more, has a front luminance of 20% or more brighter than the EL display of the comparative example.
In addition, an EL display provided with an optical unit having a haze of 20% or less in a range less than the critical angle includes an EL display not provided with an optical unit (Table 8), and an unevenness provided by roughening the surface of a transparent substrate. It can be seen that the front luminance can be increased as compared with the EL display of the comparative example (conventional).

[0080]

As described above, according to the EL device of the present invention, of the light emitted from the light emitting layer, light incident on the light transmitting substrate at a narrow angle (less than the critical angle) is emitted to the outside with low scattering. In addition, light incident on the light-transmitting substrate at a wide angle (greater than or equal to the critical angle) can be emitted to the outside, and the brightness in the front direction (in the normal direction and in the vicinity thereof) can be improved. Further, according to the EL display of the present invention, a bright display can be obtained and the display quality can be improved by using the EL device of the present invention having such improved frontal luminance as the EL display. . Further, since the liquid crystal device of the present invention is provided with the EL lighting device of the present invention in which the luminance in the front direction is improved, a bright display can be obtained and the display quality can be improved. Further, since the electronic apparatus of the present invention is provided with the liquid crystal device using the EL display or the EL lighting device of the present invention in which the luminance in the front direction is improved, a display means capable of obtaining excellent display quality is provided. Electronic device provided with the electronic device.

[Brief description of the drawings]

FIG. 1 is an explanatory view of an embodiment in which an EL device of the present invention is applied to an EL display, and is a plan view as viewed from a substrate side.

FIG. 2 is a schematic cross-sectional view showing a part of the EL display of FIG. 1, and is a cross-sectional view taken along the line AA ′ of FIG.

FIG. 3 is a diagram showing a main part of the EL display of FIG. 1, and is a schematic enlarged sectional view showing one EL element and a peripheral portion thereof.

FIG. 4 is a schematic view showing the operation of optical means provided in the EL display of FIG.

FIG. 5 is a schematic view showing another operation of the optical means provided in the EL display of FIG. 1;

FIG. 6 is a diagram showing optical characteristics used in the present embodiment and optical characteristics of an optical film constituting the optical unit.

FIG. 7 is an explanatory diagram illustrating a positional relationship among an optical unit, a light source, and a light receiving unit when measuring parallel line transmittance.

FIG. 8 is an explanatory diagram showing a relationship between incident light, parallel ray transmitted light, diffuse transmitted light, and backscattered light and forward scattered light with respect to the optical means.

FIG. 9 is a schematic diagram showing an example of a cross-sectional structure of an optical film produced by a hologram technique which constitutes an optical unit used in the present embodiment.

FIG. 10 is a schematic diagram showing a method for producing a target optical means using the optical film produced by the hologram technique of FIG.

FIG. 11 is a diagram showing the scattering and / or diffraction characteristics of the optical means provided in the EL display of the embodiment.

12A and 12B are explanatory diagrams of a liquid crystal device provided with an EL lighting device to which the EL device of the present invention is applied. FIG. 12A is a cross-sectional view illustrating an example of use as a reflective type, and FIG. It is sectional drawing which shows the example at the time of using as a transmission type.

FIG. 13 is a schematic enlarged sectional view showing an EL lighting device provided in the liquid crystal device of FIG.

FIG. 14 illustrates an example of an electronic apparatus including a liquid crystal device including the EL display according to the embodiment of the present invention or the EL lighting device according to the embodiment. FIG. 14A is a perspective view illustrating a mobile phone. FIG. 14B is a perspective view showing an example of a portable information processing apparatus, and FIG. 14C is a perspective view showing an example of a wristwatch-type electronic device.

FIG. 15A is a diagram showing the optical characteristics of the optical film of the example, and FIG. 15B is an explanatory diagram of the direction in which the optical characteristics of FIG. 15A are measured.

FIG. 16 is an explanatory diagram of a method of laminating an optical film according to an example, and is a diagram illustrating a positional relationship of directivity axes when an optical unit obtained by laminating the optical films is viewed from above.

17 (A) is a diagram showing the optical characteristics of the optical film of the example, and FIG. 15 (B) is an explanatory diagram of the direction in which the optical characteristics of FIG. 17 (A) are measured.

FIG. 18 is a schematic sectional view showing an example of a conventional EL display.

[Explanation of symbols]

 1, 161: Light-transmitting substrate 10, 11, 12, 13, 210: EL element 2, 162, 2R, 2G, 2B: Light-transmitting electrode 3, 163: Hole transport layer 4, 4R, 4G, 4B, 164 Light emitting layer 8 Partition wall 20 Optical means 21 Optical film 41 Phase difference plate (λ / 4 plate) 42 Polarizing plate 110: liquid crystal device 111: liquid crystal panel 160: EL lighting device L1, L3: incident light L2: scattered light and / or diffracted light L4: weakly scattered light and / or transmitted light L5: Parallel line transmitted light H: Normal direction α, α1, α2: Directivity axis β1: Angle of inclination of light-transmitting substrate from normal direction β2: Optical means 20a... A region showing a critical angle or more 20b... Less than the critical angle 500: Cellular phone body 501: EL display unit (display unit) 600: Information processing device 601: Input unit 602: EL display unit (display unit) 603: Information Processing body 700: Clock body 701: EL display unit (display means)

Claims (28)

[Claims] 1. A plurality of EL elements each comprising at least one organic layer including a light-emitting layer and a pair of electrodes facing each other via the organic layer are arranged in a matrix on one surface of a light-transmitting substrate. The at least one electrode of the pair of electrodes located on the light-transmitting substrate side of the pair of electrodes is formed of a light-transmitting electrode, and can be individually energized to the EL element. An EL device in which light emitted from the light-emitting layer is emitted toward the light-transmitting substrate, wherein an optical unit is provided on the other surface of the light-transmitting substrate,
The optical means scatters and / or diffracts at least a part of the light from the light emitting layer incident on the light transmissive substrate, which is repeatedly totally reflected, and emits it to the outside, and weakly scatters and / or disperses other light. Alternatively, an EL device which transmits and emits light to the outside. 2. An EL element comprising at least one organic layer including a light-emitting layer and a pair of electrodes facing each other via the organic layer is disposed on one surface of a light-transmitting substrate,
At least one of the pair of electrodes located on the light-transmitting substrate side is formed of a light-transmitting electrode, and is capable of conducting electricity to the EL element. An EL device in which emitted light is emitted to the light transmissive substrate side, wherein an optical unit is provided on the other surface of the light transmissive substrate,
The optical means scatters and / or diffracts at least a part of the light from the light emitting layer incident on the light transmissive substrate, which is repeatedly totally reflected, and emits it to the outside, and weakly scatters and / or disperses other light. Alternatively, an EL device which transmits and emits light to the outside. 3. The optical means according to claim 1, wherein at least a part of the incident light having a critical angle or more in the light from the light emitting layer incident on the light transmitting substrate is strongly scattered and emitted to the outside, and is less than the critical angle. 3. The EL device according to claim 1, wherein the incident light is weakly scattered or transmitted and emitted to the outside. 4. The optical means diffracts at least a part of incident light having a critical angle or more in the light from the light emitting layer incident on the light transmissive substrate and emits the light to the outside. 3. The EL device according to claim 1, wherein light is transmitted and emitted to the outside. 5. The optical means, wherein at least a part of incident light having a critical angle or more out of the light from the light emitting layer incident on the light transmissive substrate is strongly scattered and diffracted and emitted to the outside, 3. The incident light of less than 1 is weakly scattered and / or transmitted and emitted to the outside.
An EL device according to claim 1. 6. The optical device according to claim 1, wherein the light from the light-emitting layer incident on the light-transmitting substrate is β1 ≧ sin ⁻¹ (1 / m
1) The incident light that satisfies the condition (where β1 is the inclination angle of the light transmitting substrate from the normal direction, 1 is the refractive index of air, and m1 is the refractive index of the light transmitting substrate). At least a part is scattered and / or diffracted and emitted to the outside, and β1
The EL according to any one of claims 1 to 5, wherein the incident light satisfying the condition <sin ^-1 (1 / m1) is weakly scattered and / or transmitted and emitted to the outside.
device. 7. The optical means according to claim 1, wherein: β1 ≧ sin ^-1 (1 / m
1) Satisfies the condition of -10 ° (where β1 is the inclination angle of the light-transmitting substrate from the normal direction, 1 is the refractive index of air, and m1 is the refractive index of the light-transmitting substrate). At least a part of the incident light is scattered and / or diffracted and emitted to the outside, and the incident light satisfying the condition of β1 <sin ⁻¹ (1 / m1) −10 ° is weakly scattered and / or transmitted and emitted to the outside. The EL device according to any one of claims 1 to 5, wherein the EL device is used. 8. The optical device according to claim 1, wherein β1 ≧ 40 ° of the light from the light emitting layer incident on the light-transmitting substrate (where β1 is a tilt from a normal direction of the light-transmitting substrate). At least a part of the incident light satisfying the angle
6. The method according to claim 1, wherein incident light that is diffracted and emitted to the outside and satisfies the condition of β1 = 0 is weakly scattered and / or transmitted and emitted to the outside. The EL device according to any one of the preceding claims. 9. The optical unit according to claim 1, wherein β1 ≧ 40 ° out of the light from the light emitting layer incident on the light-transmitting substrate (where β1 is an inclination from a normal direction of the light-transmitting substrate). Angle) is at least partially scattered and / or diffracted and emitted to the outside, and the incident light satisfying the condition of β1 <40 ° is weakly scattered and / or transmitted and emitted to the outside. The EL device according to any one of claims 1 to 5, wherein: 10. The optical means, wherein β2 of light incident on the optical means from the light emitting layer via the light transmitting substrate is provided.
≧ sin ⁻¹ (1 / m 2) (where β 2 is the inclination angle of the optical means from the normal direction, 1 is the refractive index of air, m
2 is the refractive index of the optical means. At least a part of the incident light satisfying the condition (2) is scattered and / or diffracted and emitted to the outside. The incident light satisfying the condition of β2 <sin ^-1 (1 / m2) is weakly scattered and / or transmitted and emitted to the outside. The EL device according to any one of claims 1 to 9, wherein the EL device is used. 11. The optical means, wherein β2 of light incident on the optical means from the light-emitting layer via the light-transmitting substrate.
≧ sin ⁻¹ (1 / m2) −10 ° (where β2
Is the angle of inclination of the optical means from the normal direction, 1 is the refractive index of air, and m2 is the refractive index of the optical means. At least a portion of the incident light satisfying) is emitted to the outside by scattering and / or ^{diffraction, β2 <sin -1 (1 /} m2) -10 ° becomes satisfying incident light weakly scattering and / or transmitted to 10. The light is emitted to the outside.
An EL device according to any one of the preceding claims. 12. The optical means, wherein β2 of light incident on the optical means from the light emitting layer via the light transmitting substrate is provided.
At least a part of the incident light satisfying the condition of ≧ 40 ° (where β2 is the inclination angle from the normal direction of the optical means) is strongly scattered and / or diffracted and emitted to the outside, and β2 = 0 °
2. An incident light satisfying the following condition, which is weakly scattered and / or transmitted and emitted to the outside.
10. The EL device according to any one of claims 1 to 9. 13. The optical means, wherein β2 of light incident on the optical means from the light-emitting layer via the light-transmitting substrate.
At least a part of the incident light satisfying the condition of ≧ 40 ° (where β2 is the inclination angle from the normal direction of the optical means) is scattered and / or diffracted and emitted to the outside, and β2 <40 °
2. An incident light satisfying the following condition, which is weakly scattered and / or transmitted and emitted to the outside.
10. The EL device according to any one of claims 1 to 9. 14. The method according to claim 1, wherein the refractive index m1 of the light-transmitting substrate and the refractive index m2 of the optical means are the same or substantially equal. EL device. 15. The EL device according to claim 1, wherein a refractive index m1 of the light transmitting substrate and a refractive index m2 of the optical unit satisfy a relationship of m1 ≦ m2. . 16. The optical means according to claim 1, wherein, out of the light from the light emitting layer incident on the light transmitting substrate, incident light having a critical angle or more is emitted outside with a haze of 50% or more, and incident light having a critical angle is less than 50%. The light emitting device according to any one of claims 1 to 15, wherein the light is emitted to the outside at a haze of 20% or less.
L device. 17. The EL device according to claim 1, wherein the optical unit is formed by laminating a plurality of optical films. 18. The EL device according to claim 17, wherein the plurality of optical films are stacked with their axes indicating parallel light transmittance indicating directivity shifted from each other. 19. The EL device according to claim 17, wherein the optical film is a hologram. 20. An EL display using the EL device according to claim 1 or any one of claims 3 to 19. 21. An EL device which emits red light as the EL element.
L element, EL element emitting green light, and EL emitting blue light
21. An element according to claim 20, wherein said element is used.
L display. 22. The optical device according to claim 20, wherein a retardation plate and a polarizing plate are provided on the surface of the optical unit opposite to the light transmitting substrate side in order from the optical unit side.
2. The EL display according to 1. 23. An EL lighting device using the EL device according to claim 2 or 3 to 19. 24. An EL device which emits red light as the EL element.
L element, EL element emitting green light, and EL emitting blue light
The EL lighting device according to claim 23, wherein at least one of an element and an EL element that emits white light is used. 25. An EL emitting blue light as the EL element
An element is used, and means for converting the wavelength of light emitted in blue by the light emitting layer is provided between the EL element and the light transmitting substrate or between the light transmitting substrate and the optical means or on the surface of the optical means. The EL lighting device according to claim 23, wherein the EL lighting device is provided. 26. A liquid crystal panel comprising a pair of substrates, a liquid crystal layer sandwiched between these substrates, and said liquid crystal panel provided on one side of said liquid crystal panel opposite to the liquid crystal layer. 26. A liquid crystal device comprising the EL lighting device according to any one of claims 25 to 25. 27. The liquid crystal device according to claim 26, wherein the liquid crystal panel has a transflective layer provided on one of the substrates on the liquid crystal layer side. 28. An electronic apparatus comprising the EL display according to claim 20 or the liquid crystal device according to claim 26 as display means.