JP2008010416A - Lighting device and liquid crystal display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To propose a light source structure providing addition of polarization and improvement of light usage efficiency in a device used for a light source of a system using polarization properties, in the case specifically when this light source is applied to a liquid crystal panel as a backlight, and a light-source-integrated structure of a liquid crystal display system using this light source as well. <P>SOLUTION: The light source comprises a first electrode formed of a reflective material, and a second electrode composed of an EL layer and a transparent conductive film. The light emitted from the EL layer is extracted from the second electrode. A selective reflection structure is prepared without an intervention of an air layer on the side where the light from the second electrode is extracted to reflect the light except for a specific polarization component that is transmitted. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a lighting device, a liquid crystal element in which a surface light source is integrally mounted, and a liquid crystal display device.

  Improvements in flat panel displays such as liquid crystal panels have progressed, and higher quality images, lower power consumption, and longer life have been achieved. On the other hand, PDP (Plasma Display Panel), FED (Field Emission Display), SED (Surface-Conduction Electron-Emitter Display), various kinds of organic electroluminescence (Electro Luminescence), EL and the like below. Light-emitting displays have been studied and partly put into practical use. The display using these self-luminous display devices is being developed for the purpose of breaking into the liquid crystal display market. One feature of these displays is that the thickness of the display portion of the product can be reduced by eliminating the need for a backlight unlike liquid crystal, which is advantageous in terms of power consumption.

  Even for liquid crystal displays with rich production technology, infrastructure, and small to large product repertoires, the launch of the above self-luminous displays is a threat, and displays that use liquid crystal panels still need to address the remaining issues It has become.

  The problems in the liquid crystal display mentioned above are the space for the backlight and the power consumption for driving it, and the need for polarized light as the liquid crystal input light. Improvements such as loss of light other than polarized light and an increase in cost and space due to a structure such as an optical film for making incident light uniform in the surface can be considered.

  In order to solve the above problems, the development of downsizing, higher efficiency, and longer life of the cold cathode tube has been continued. Alternatively, instead of a cold-cathode tube, research on improving the light emission efficiency of a light-emitting diode has been conducted, and the improvement is progressing (for example, see Patent Document 1). However, these light sources are line or point light sources, and in order to make the luminance uniform, a scattering plate or a light guide plate having strong scattering properties is required.

Furthermore, in order to make effective use of light, there are some measures that combine a plurality of types of expensive brightness enhancement films between the light source and the liquid crystal panel. These films transmit light components of predetermined polarization, return other components to the light source side, reflect this light on the light source side, change the polarization direction, and reuse it as incident light on the panel again. Is.
JP-A-8-248420

However, since these films are arranged via a point light source or a line light source and an air layer having a large difference in refractive index of light, loss such as interface loss is not overlooked and further improvement is required. In addition, these costs are high, and problems such as requiring an installation space remain.

  The present invention relates to an illumination device used as a light source for an apparatus that uses polarization characteristics. Specifically, when the illumination device is applied to a liquid crystal panel as a backlight, a polarization function is imparted and light utilization efficiency is improved. We propose a lighting device structure that improves the efficiency. Furthermore, it aims at proposing the light source integrated mounting structure of the liquid crystal display device using this illuminating device.

  The structure of the lighting device of the present invention includes at least an EL layer between the first electrode and the second electrode facing each other and the first electrode and the second electrode. The first electrode, the EL layer, and the second electrode are stacked in this order, or the second electrode, the EL layer, and the first electrode are stacked in this order. Light emitted from the EL layer is emitted from the second electrode. It is taken out.

  The first electrode of the light-emitting element is an electrode that can reflect light from the light-emitting layer. The second electrode is an electrode that can transmit light from the light emitting layer.

  Further, there is a structure having a function of selectively transmitting an arbitrary polarization component and reflecting other light components in the direction of light transmitted through the second electrode (hereinafter referred to as a selective reflection structure). The light component selectively transmitted here can be used as incident light to the liquid crystal. Here, the light of this component is expressed as effective light. Further, the reflected light of components other than the selectively transmitted light is expressed as unnecessary light. In the present invention, unnecessary light does not mean unnecessary light, but means light that can be extracted as effective light by changing the polarization state by reflection or the like.

Here, the component of the reflected light that is unnecessary light is reflected between the reflective first electrode provided in the illumination device and the selective reflection structure, so that the polarization plane and the polarization state of the reflected light are reflected. To change. In order to change the polarization state more efficiently, the functions of the phase difference plate and the scattering plate may be used alone or in combination. Thereby, the light is changed to light having the same component as the transmitted light, and this component is also extracted as effective light.

As a specific example of the selective reflection structure, a reflective polarizing plate formed by a combination of a cholesteric liquid crystal and a polarizing film may be used, or a P-wave and S-wave polarized light separation optical system such as a polarizing beam splitter (hereinafter referred to as PBS). You may comprise combining. This structure alone may be used, but more desirably, in order to increase the conversion efficiency, a λ / 4 retardation plate, a scattering plate, A structure having an optical action such as a scattering structure may be used alone or in combination. Here, these combined structures are broadly defined as selective reflection structures.

The light emitted from the surface light source that has applied the driving voltage to the first electrode and the second electrode and caused the EL layer to emit light therebetween forms a selective reflection structure having a selective reflection function of polarized light. Only the light component of a predetermined polarization is transmitted, and unnecessary light of other components is reflected. Utilizing this action, a change in polarization plane and polarization state accompanied by unnecessary light reflection is caused between the selective reflection structure and the reflection electrode of the illumination device. Thereby, the light of an illuminating device can be efficiently taken out in an arbitrary polarization state on the exit side of the illuminating device. Usually, linearly polarized light is used.

One of the features here is that it can be arranged without interposing an air layer, so that the interface loss at the film surface arranged on the air layer and the selective reflection structure can be reduced. As a result, even in the case of multiple reflections between the first electrode, which is a reflective electrode, and the selective reflection structure, the loss can be reduced compared to the conventional case.

One embodiment of the lighting device of the present invention includes a first electrode made of a reflective material, an EL layer, and a second electrode made of a light-transmitting conductive film, and light emitted from the EL layer is extracted from the second electrode. In addition, a selective reflection structure is provided on the side from which the light of the second electrode is extracted without interposing an air layer. The selective reflection structure transmits light of a specific polarization component and transmits other light. Has the function of reflecting.

In one embodiment of the lighting device of the present invention, a first electrode, an EL layer, and a second electrode are stacked in this order on a substrate, the first electrode is made of a reflective material, and the second electrode is a light-transmitting material. The light emitted from the EL layer is extracted from the second electrode, and a selective reflection structure is provided on the side from which the light from the second electrode is extracted without interposing an air layer. The selective reflection structure has a function of transmitting light of a specific polarization component and reflecting other light.

In one embodiment of the lighting device of the present invention, a second electrode made of a light-transmitting material, an EL layer, and a first material made of a reflective material are formed on one surface of a substrate made of a light-transmitting material. The selective reflection structure is provided on the other surface of the substrate, the light emitted from the EL layer is extracted from the second electrode, and the light extracted from the second electrode passes through the substrate. The light is incident on the selective reflection structure without interposing any air layer, and the selective reflection structure has a function of transmitting light of a specific polarization component in the incident light and reflecting other light.

In one embodiment of the lighting device of the present invention, a second electrode made of a light-transmitting material, an EL layer, and a first material made of a reflective material are formed on one surface of a substrate made of a light-transmitting material. The other surface of the substrate is provided in contact with the adhesive layer, the selective reflection structure is provided in contact with the adhesive layer, and the light emitted from the EL layer is extracted from the second electrode, The light extracted from the second electrode is incident on the selective reflection structure through the substrate and the adhesive layer, and the selective reflection structure transmits light of a specific polarization component in the incident light, and other light. Has the function of reflecting the light.

In one embodiment of the liquid crystal display device of the present invention, a liquid crystal is sandwiched between a pair of substrates, a pixel electrode formed of a light-transmitting conductive film arranged in a matrix on one of the pair of substrates, and connected to the pixel electrode One substrate is a substrate having a light-transmitting property and an insulating property, and the other substrate is a first electrode made of a reflective material, an EL layer, and a light-transmitting conductive film. The light emitted from the EL layer is extracted from the second electrode, and the second electrode is selectively reflected without an air layer on the side from which the light is extracted. A structure is provided.

In one embodiment of the liquid crystal display device of the present invention, a liquid crystal is sandwiched between a pair of substrates, a pixel electrode formed of a light-transmitting conductive film arranged in a matrix on one of the pair of substrates, and connected to the pixel electrode One substrate is a substrate having translucency and insulation, and the other substrate has a selective reflection structure on a surface facing the pixel electrode, and the other substrate. A second electrode made of a light-transmitting conductive film, an EL layer, and a first electrode made of a reflective material are sequentially stacked on the back surface of the other substrate, and the other substrate has light-transmitting properties and insulating properties.

In one embodiment of the liquid crystal display device of the present invention, a liquid crystal is sandwiched between a pair of substrates, a pixel electrode including a transparent photoconductive film disposed in a matrix on one of the pair of substrates, and connected to the pixel electrode. One substrate is a light-transmitting and insulating substrate, and the other substrate is provided with an adhesive layer in contact with the surface facing the pixel electrode, and in contact with the adhesive layer. A second electrode made of a light-transmitting conductive film, an EL layer, and a first electrode made of a reflective material are sequentially stacked on the back surface of the other substrate. It has translucency and insulation.

In the above configuration, the selective reflection structure may include an optical structure that combines a polarization beam splitter function configured to transmit the P wave and reflect the S wave toward the first electrode. Further, the selective reflection structure has a retardation plate that transmits circularly polarized light components in a specific rotation direction of incident light and converts the transmitted circularly polarized light components into linearly polarized light. It may have a reflective polarization function configured to reflect the component light toward the first electrode.

Here, in the light-emitting element of the present invention, the EL layer between the first electrode and the second electrode may have at least one light-emitting layer. A plurality of light emitting layers may be provided in the EL layer.

In addition, a light-emitting element in which layers such as an electron injection layer, an electron transport layer, a hole blocking layer, a hole transport layer, and a hole injection layer are appropriately formed in addition to the light-emitting layer is also included in the scope of the present invention.

  In addition, the EL layer of the present invention may be one in which an inorganic light emitting material is dispersed in a binder, may be formed as a thin film, and is formed by providing one or more dielectric layers in addition to the light emitting layer. A light emitting element is also included in the category of the present invention.

As an effect of the present invention, by using a surface light source, it is possible to use emitted light with little luminance unevenness without requiring a scattering optical system or the like. In addition, since the emitted light can be handled by the surface, the distance between the light source and the selective reflection structure can be arranged in a parallel plane at a very short distance, and the structure can be configured to be integrated with the light source without including an air layer. In addition, since the difference in refractive index can be reduced, a configuration with less interface loss can be obtained. Based on these characteristics, in addition to a single polarization component, a reflected light source can be converted and extracted so that a polarized light source with high light use efficiency can be configured.

Furthermore, since these functions can be incorporated on the same substrate, it can be used not only as a backlight source for liquid crystals but also as a counter substrate for liquid crystals, and a liquid crystal panel with a built-in backlight can be realized. It becomes.

With these effects, it is possible to realize low power consumption and thinning of the liquid crystal panel.

  Embodiments of the present invention will be described below with reference to the drawings. However, the present invention can be implemented in many different ways. For example, the embodiments can be appropriately combined. It will be readily understood by those skilled in the art that various changes can be made in form and detail without departing from the spirit and scope of the invention. Therefore, the present invention should not be construed as being limited to the description of the embodiment modes.

(Embodiment 1)
FIG. 1 is a cross-sectional view of an illumination device having a polarization function according to this embodiment. A first electrode 102 made of a reflective material is provided on one surface of the substrate 101, an insulating layer 103 is provided after the first electrode is formed, and an EL layer 104 is provided in a light emitting region on the first electrode. A second electrode 105 made of a light-transmitting (conductive film) material is provided over the EL layer serving as the light-emitting region. Further, a selective reflection structure 107 is disposed via the adhesive layer 106.

  In this configuration, the first electrode extraction portion 111 and the second electrode extraction portion 112 are also formed on the same surface.

Here, the selective reflection structure 107 forms an assembly (hereinafter referred to as a PBS array) 109 of PBS blocks 108 composed of two PBSs whose optical action surfaces (hereinafter referred to as optical axis surfaces) are arranged at an angle of 90 degrees. ing.

The S wave component (hereinafter referred to as S wave) of the light incident from the light source is reflected between the two PBS blocks 108, and the S wave reflected light is returned to the light source side. At this time, the P wave component (hereinafter referred to as P wave) is transmitted through this optical working surface and becomes the light emitted from the light source.

  Furthermore, here, an example is shown in which a λ / 4 retardation plate (hereinafter referred to as λ / 4 plate) 110 is disposed at a predetermined position as a component of the selective reflection structure 107. S-wave reflected light reflected and returned to the light source side by the PBS block 108 as a set is converted into light of a circular or elliptically polarized component in a certain rotation direction by passing through the λ / 4 plate 110. This returned circular or elliptically polarized reflected light is reflected again by the reflecting surface of the first electrode and is incident on the λ / 4 plate again, so that a phase difference of λ / 4 is further given. It is possible to pass through the PBS block after being converted into light having a wave component or light having a large P wave component. In the present invention, light that has been reflected and whose direction has been changed in the selective reflection structure is referred to as reflected light.

  In other words, the λ / 4 plate 110 of the present embodiment is arranged to change the polarization state most efficiently. In this example, the λ / 4 plate 110 is formed only on one side of the PBS block 108, but it may be formed on the entire surface of the PBS array 209 as in the λ / 4 plate 210 as shown in FIG. Of course, an improvement can be expected compared with a conventional light source even if it is not arranged to reduce the construction cost.

In the present embodiment, the selective reflection structure 107 has been described with the PBS block 108 composed of two PBSs whose optical action surfaces (hereinafter referred to as optical axis surfaces) are arranged at an angle of 90 degrees. This angle is not limited to 90 degrees because it is intended to transmit and reflect unwanted light back to the light source side. For example, it is sufficient that the purpose can be achieved at 60 degrees or 140 degrees.

As an effect of the present embodiment, by using a surface light source, it is possible to use emitted light with little luminance unevenness without requiring a scattering optical system or the like. In addition, since the emitted light can be handled by the surface, it can be arranged in parallel plane at a distance that is very close to the next selective reflection structure, and it can be configured with a structure that is integrated with the light source without including an air layer. In addition, since the difference in refractive index can be reduced, a configuration with less interface loss can be obtained. Based on these characteristics, in addition to a single polarization component, a reflected light source can be converted and extracted so that a polarized light source with high light use efficiency can be configured.

Furthermore, since these functions can be incorporated on the same substrate, it can be used not only as a backlight source for liquid crystals but also as a counter substrate for liquid crystals, and a liquid crystal panel with a built-in backlight can be realized. It becomes.

With these effects, it is possible to realize low power consumption and thinning of the liquid crystal panel.

(Embodiment 2)
FIG. 3 shows a cross-sectional view of the illumination device having the polarization function of the present embodiment. A light source structure is arranged on one side of one substrate, and a selective reflection structure is arranged on the other side. Here, this structure is expressed as a double-sided structure.

A second electrode 1105 made of a light-transmitting material is provided over one surface of the substrate 1101, and an insulating layer 1103 is provided after the second electrode is formed, and an EL layer 1104 is provided in a light-emitting region over the second electrode. Yes. A first electrode 1102 made of a reflective material is provided over the EL layer 1104 serving as the light emitting region. Further, a protective film 1113 is disposed on the first electrode 1102.

  Further, a selective reflection structure 1107 is disposed on the other surface of the substrate via the same position adhesive layer 1106 as the region of light emitted from the second electrode.

  This configuration is characterized in that the first electrode extraction portion 1111 and the second electrode extraction portion 1112 are arranged on the side opposite to the surface of the light emitted from the selective reflection structure.

  Since the optical action from the light source is the same as that of the first embodiment except that a glass substrate is interposed therebetween, it is omitted here.

  The λ / 4 plate 1110 of the present embodiment is arranged to change the polarization state most efficiently. In this example, the λ / 4 plate 1110 is formed only on one side of the PBS block 1108. FIG. 4 shows an example in which the λ / 4 plate is omitted in the double-sided embodiment 2.

In the present embodiment, the structure in which the scatterer 2110 is dispersed in the adhesive layer 2106 as a scattering layer is not the property of changing the polarization state, but mainly has the effect of intentionally changing the polarization plane. This is used to improve the extraction efficiency and to scatter the emitted light from the light source to further improve the uniformity of luminance. Although it is inferior to the arrangement of the λ / 4 plate 1110 in terms of the extraction efficiency of the emitted light, there is an advantage that a simple structure can be obtained from the production surface and cost can be reduced.

As an effect of the present embodiment, by using a surface light source, it is possible to use emitted light with little luminance unevenness without requiring a scattering optical system or the like. In addition, since the emitted light can be handled by the surface, it can be arranged in parallel plane at a distance that is very close to the next selective reflection structure, and it can be configured with a structure that is integrated with the light source without including an air layer. In addition, since the difference in refractive index can be reduced, a configuration with less interface loss can be obtained. Based on these characteristics, in addition to a single polarization component, a reflected light source can be converted and extracted so that a polarized light source with high light use efficiency can be configured.

Furthermore, since these functions can be incorporated on the same substrate, it can be used not only as a backlight source for liquid crystals but also as a counter substrate for liquid crystals, and a liquid crystal panel with a built-in backlight can be realized. It becomes.

With these effects, it is possible to realize low power consumption and thinning of the liquid crystal panel.

(Embodiment 3)
FIG. 5 shows a cross-sectional view of the illumination device having the polarization function of the present embodiment. A first electrode 302 made of a reflective material is provided on one surface of the substrate 301, an insulating layer 303 is provided after the first electrode is formed, and an EL layer 304 is provided in a light emitting region on the first electrode. A second electrode 305 made of a light-transmitting (conductive film) material is provided over the EL layer serving as the light-emitting region. Further, a selective reflection structure 307 is disposed via the passivation layer 306.

  In this configuration, the first electrode extraction portion 310 and the second electrode extraction portion 311 are also formed on the same surface.

Here, the selective reflection structure 307 transmits only a predetermined circularly polarized light component, and this transmitted light component is converted into linearly polarized light by a laminated phase difference plate and output. It also has the effect of reflecting other components of light.

  Further, here, an example is shown in which a λ / 4 plate 309 is disposed at a predetermined position as a component of the selective reflection structure 307. By passing the λ / 4 plate 309, the light passing through the optical film changes its polarization state. The light incident on the reflective polarizing plate 308 is first polarized and converted when passing through the λ / 4 plate 309. Of this incident light that has undergone polarization conversion, only a predetermined circularly polarized light component is transmitted through the reflective polarizing plate 308, converted into linearly polarized light by the polarizing plate, and output as effective light.

  Further, unnecessary light reflected by the reflective polarizing plate 308 passes through the λ / 4 plate 309 again, and is converted into polarized light and returned to the light source direction. This unnecessary light is reflected by the first electrode of the light source, and becomes incident light on the selective reflection structure again. Here, the light is converted by the λ / 4 plate 309, and a predetermined circularly polarized light component is emitted as effective light.

  The λ / 4 plate 309 in this example is arranged to change the polarization state more efficiently, but FIG. 6 shows an example in which the λ / 4 plate is not used in order to give priority to the manufacturing cost. A first electrode 402 made of a reflective material is provided on one surface of the substrate 401, an insulating layer 403 is provided after the first electrode is formed, and an EL layer 404 is provided in a light emitting region on the first electrode. A second electrode 405 made of a light-transmitting (conductive film) material is provided over the EL layer serving as the light-emitting region. Further, a selective reflection structure 407 including a reflective polarizing plate 408 is disposed through the passivation layer 406. In this configuration, the first electrode extraction portion 409 and the second electrode extraction portion 410 are also formed on the same surface. Even with this configuration, improvement can be expected as compared with the conventional light source.

As an effect of the present embodiment, by using a surface light source, it is possible to use emitted light with little luminance unevenness without requiring a scattering optical system or the like. In addition, since the emitted light can be handled by the surface, it can be arranged in parallel plane at a distance that is very close to the next selective reflection structure, and it can be configured with a structure that is integrated with the light source without including an air layer. In addition, since the difference in refractive index can be reduced, a configuration with less interface loss can be obtained. Based on these characteristics, in addition to a single polarization component, a reflected light source can be converted and extracted so that a polarized light source with high light use efficiency can be configured.

Furthermore, since these functions can be incorporated on the same substrate, it can be used not only as a backlight source for liquid crystals but also as a counter substrate for liquid crystals, and a liquid crystal panel with a built-in backlight can be realized. It becomes.

With these effects, it is possible to realize low power consumption and thinning of the liquid crystal panel.

(Embodiment 4)
FIG. 7 shows a cross-sectional view of the illumination device having the polarization function of this embodiment. Another example of a double-sided structure in which a light source structure is arranged on one side of one substrate and a selective reflection structure is arranged on the other side is shown.

A second electrode 3305 made of a light-transmitting material is provided over one surface of the substrate 3301, an insulating layer 3303 is provided after the second electrode is formed, and an EL layer 3304 is provided in a light-emitting region over the second electrode. Yes. A first electrode 3302 made of a reflective material is provided over the EL layer 3304 serving as the light emitting region. Further, a protective film 3306 is disposed on the first electrode 3302.

  Furthermore, the same position selective reflection structure 3307 as the region of light emitted from the second electrode is disposed on the other surface of the substrate.

  In this configuration, the first electrode extraction portion 3310 and the second electrode extraction portion 3311 are arranged on the opposite side to the surface of the light emitted from the selective reflection structure 3307.

  The optical action from the light source is the same as that of the third embodiment except that a glass substrate is interposed between the light source and the selective reflection structure, and is omitted here.

  The selective reflection structure 3307 of this embodiment includes a λ / 4 plate 3309 and a reflective polarizing plate 3308 in order to efficiently change the polarization state. Although the optical thin film is formed directly on the substrate, a film member including an adhesive layer may be used for these.

Here, FIG. 8 shows an example in which the λ / 4 plate is omitted and a scattering layer is used in Embodiment 3 having a double-sided structure. Note that the selective reflection structure 4307 includes a reflective polarizing plate 4312.

In this embodiment, the scattering layer 4309 is dispersed in the adhesive layer 4308 as a scattering layer, so that not the property of changing the polarization state but mainly the effect of intentionally changing the polarization plane. This is used to improve the extraction efficiency and to scatter the emitted light from the light source to further improve the uniformity of luminance. There is an advantage that the structure can be simple from the viewpoint of manufacturing and the cost can be reduced.

As an effect of the present embodiment, by using a surface light source, it is possible to use emitted light with little luminance unevenness without requiring a scattering optical system or the like. In addition, since the emitted light can be handled by the surface, it can be arranged in parallel plane at a distance that is very close to the next selective reflection structure, and it can be configured with a structure that is integrated with the light source without including an air layer In addition, since the difference in refractive index can be reduced, a configuration with less interface loss can be obtained. Based on these characteristics, in addition to a single polarization component, a reflected light source can be converted and extracted so that a polarized light source with high light use efficiency can be configured.

Furthermore, since these functions can be incorporated on the same substrate, it can be used not only as a backlight source for liquid crystals but also as a counter substrate for liquid crystals, and a liquid crystal panel with a built-in backlight can be realized. It becomes.

With these effects, it is possible to realize a low-power consumption and thin panel of the liquid crystal panel.

(Embodiment 5)
In this embodiment, an example used for an active matrix liquid crystal panel having a display function will be described with reference to FIG.

  FIG. 9A is a schematic view of an active matrix liquid crystal panel as viewed from the front. A counter substrate 801 is fixed to the element substrate 800 with a sealant 802.

  The element substrate 800 is provided with a pixel portion 803, a gate driver circuit 804, and a source driver circuit 805. Each of the gate driver circuit 804 and the source driver circuit 805 is connected to an FPC (flexible printed circuit) 806 that is an external input terminal via a wiring group. The source driver circuit 805 and the gate driver circuit 804 receive a video signal, a clock signal, a start signal, a reset signal, various power supplies, and the like from the FPC 806, respectively.

  Transistors in the pixel portion 803, the gate driver circuit 804, and the source driver circuit 805 are formed of thin film transistors (hereinafter referred to as TFTs). Note that the gate driver circuit 804 and the source driver circuit 805 are not necessarily provided on the same element substrate 800 as the pixel portion 803 as described above. For example, an IC chip is formed on an FPC on which a wiring pattern is formed. (TCP) etc. may be used and provided outside the substrate. Further, in the gate driver circuit 804 and the source driver circuit 805, a part of the circuit may be provided on the element substrate 800 and a part may be provided outside the element substrate 800.

  FIG. 9B shows a cross section taken along line A-A ′ of FIG. This counter substrate 801 has the light source with polarization action of the present invention, and a predetermined interval (hereinafter referred to as a cell gap) is provided between the emission surface of the effective light from the counter substrate and the element surface of the element substrate 800. Keep them facing each other. A light source integrated panel is formed by orienting liquid crystal 807 inside a sealing material 802 to which these two substrates (element substrate 800 and counter substrate 801) are fixed.

Although not shown here, an alignment film subjected to alignment treatment is formed on each surface having the counter electrode 819 and the pixel electrode 823. In order to maintain the cell gap, a spacer 820 is formed on the element substrate here. Although not shown, a spacer material called a filler may also be used in the sealing material 802 together. In this structure, light is extracted from the element substrate 800 side.

  Here, on the counter substrate 801, a first electrode 808 made of a reflective material, an EL layer 809 that becomes a light emitting portion, and a second electrode 810 made of a light-transmitting conductive material are sequentially stacked. Although not described in this cross section, if there is a possibility of causing an electrical short circuit between the first electrode and the second electrode, in order to avoid this, the area other than the light emitting area and the power supply connection portion is not included. An insulating layer may be provided.

  Next, a passivation layer 811 is provided over the second electrode 810 for the purpose of preventing adverse effects of moisture and oxygen on the EL layer.

As the reflective material, a conductive film made of titanium, tungsten, nickel, gold, platinum, silver, aluminum, magnesium, calcium, lithium, or an alloy thereof can be used.

As the translucent conductive material, indium tin oxide (ITO), IZO (indium zinc oxide) in which indium oxide is mixed with zinc oxide (ZnO), conductive material in which indium oxide is mixed with silicon oxide (SiO ₂ ), organic Indium, organic tin, indium oxide containing tungsten oxide, indium zinc oxide containing tungsten oxide, indium oxide containing titanium oxide, indium tin oxide containing titanium oxide, or the like can be used.

As the planarizing film, silicon oxide, silicon nitride, silicon oxynitride, silicon nitride oxide, aluminum nitride (AlN), aluminum oxide containing nitrogen (also referred to as aluminum oxynitride) (AlON), aluminum nitride containing oxygen (nitrided oxide) (Also) (AlNO), aluminum oxide, diamond-like carbon (DLC), polysilazane, nitrogen-containing carbon film (CN), PSG (phosphorus glass), BPSG (phosphorus boron glass), alumina film, and other inorganic insulating materials It can form with the material chosen from the substance containing. A siloxane resin may also be used. Further, an organic insulating material may be used, and the organic material may be either photosensitive or non-photosensitive, and polyimide, acrylic, polyamide, polyimide amide, resist, benzocyclobutene, or the like can be used. Moreover, an oxazole resin can also be used, for example, photocurable polybenzoxazole or the like can be used.

As the passivation film, silicon nitride, silicon oxide, silicon oxynitride, silicon nitride oxide, aluminum nitride, aluminum oxynitride, aluminum nitride oxide or aluminum oxide having a nitrogen content higher than the oxygen content, diamond-like carbon (DLC), The insulating film includes a nitrogen-containing carbon film, and a single layer or a combination of the insulating films can be used. Alternatively, a siloxane resin may be used.

  In this embodiment mode, a selective reflection structure 827 that is a combination of the PBS array 814 and the λ / 4 retardation plate 813 shown in Embodiment Mode 1 is provided on the passivation layer 811 with an adhesive layer 812 interposed therebetween.

  In the liquid crystal panel, since the uniformity of the cell gap in the pixel portion 803 is important, flatness is particularly required in this display region on the counter substrate side. Therefore, a planarizing film 815 is formed on the selective reflection structure 827 by a combination of the PBS array 814 and the λ / 4 retardation plate 813.

  Further, in this embodiment mode, a black matrix (hereinafter referred to as BM) 816, a color filter 817, and an overcoat 818 are sequentially formed on the planarizing film 815 as a configuration of a liquid crystal panel capable of color display. Here, the overcoat 818 has the purpose of preventing the BM 816 and the diffused matter from the color filter 817 from adversely affecting the liquid crystal and the elements on the element substrate, in addition to the planarization effect. On this overcoat 818, a translucent conductive film to be a liquid crystal counter electrode 819 is formed.

  On the other hand, on the element substrate 800, a pixel portion 803 is configured by a pixel TFT 821, an auxiliary capacitor 822, and a pixel electrode 823 including a light-transmitting conductive film, and a source driver circuit 805 is configured by a thin film transistor including a circuit TFT 824. . Similarly, although not shown in this cross section, a gate driver circuit 804 made of a thin film transistor or the like is also configured. The source driver circuit 805 and the gate driver circuit 804 are connected to the FPC 806 through the terminal lead wiring 825 of the terminal portion 826, and various power sources and signals are applied.

  Although not shown in the cross-sectional portion of the present embodiment, the extraction portions of the first electrode 808 and the second electrode 810 are arranged inside the counter substrate 801 when the panel is formed. For this reason, the power supply to these electrodes may be electrically connected from the wiring of the element substrate 800 to the terminal lead wiring through a conductive spacer, conductive paste, or the like. The power supply wiring may be directly provided on the inner surface by increasing the size.

As an effect of the present embodiment, by using a surface light source, it is possible to use emitted light with little luminance unevenness without requiring a scattering optical system or the like. In addition, since the emitted light can be handled by the surface, it can be arranged in parallel plane at a distance that is very close to the next selective reflection structure, and it can be configured with a structure that is integrated with the light source without including an air layer. In addition, since the difference in refractive index can be reduced, a configuration with less interface loss can be obtained. Based on these characteristics, in addition to a single polarization component, a reflected light source can be converted and extracted so that a polarized light source with high light use efficiency can be configured.

Furthermore, since these functions can be incorporated on the same substrate, it can be used not only as a backlight source for liquid crystals but also as a counter substrate for liquid crystals, and a liquid crystal panel with a built-in backlight can be realized. It becomes.

With these effects, it is possible to realize a low-power consumption and thin panel of the liquid crystal panel.

(Embodiment 6)
In the present embodiment, another example used for an active matrix liquid crystal panel having a display function will be described with reference to FIG. In this embodiment, the structure shown in Embodiment 4 is adopted for the counter substrate of the liquid crystal panel.

  FIG. 10A is a schematic view of an active matrix liquid crystal panel as viewed from the front. A counter substrate 901 is fixed to the element substrate 900 with a sealant 902.

  The element substrate 900 is provided with a pixel portion 903, a gate driver circuit 904, and a source driver circuit 905. Each of the gate driver circuit 904 and the source driver circuit 905 is connected to an FPC (flexible printed circuit) 906 that is an external input terminal via a wiring group. The source driver circuit 905 and the gate driver circuit 904 receive a video signal, a clock signal, a start signal, a reset signal, various power supplies, and the like from the FPC 906, respectively.

  Transistors of the pixel portion 903 and the gate driver circuit 904 and the source driver circuit 905 which are driving circuit portions are formed of thin film transistors (hereinafter referred to as TFTs). Note that the gate driver circuit 904 and the source driver circuit 905 are not necessarily provided on the element substrate 900 which is the same substrate as the pixel portion 903 as described above, and for example, on the FPC on which a wiring pattern is formed. An IC chip mounted (TCP) or the like may be used and provided outside the substrate. Further, in the gate driver circuit 904 and the source driver circuit 905, a part of each circuit may be provided on the element substrate 900 and a part may be provided outside the element substrate 900.

  FIG. 10B shows a cross section taken along line B-B ′ of FIG. The counter substrate 901 has the light source with polarization action according to the present invention, and a predetermined interval (hereinafter referred to as a cell gap) is provided between the emission surface of the effective light from the counter substrate and the element surface of the element substrate 900. Keep them facing each other. The liquid crystal 907 is oriented inside the sealing material 902 that fixes the element substrate 900 and the counter substrate 901 to form a light source integrated panel.

Although not shown here, an alignment film subjected to alignment treatment is formed on each surface having the counter electrode 921 and the pixel electrode 925. In order to maintain the cell gap, a spacer 922 is formed on the element substrate here. Although not shown, a spacer material called a filler may also be mixed in the sealing material 902. In this structure, light is extracted from the element substrate 900 side.

  Here, a second electrode 908 made of a light-transmitting conductive material, an insulating layer 909, an EL layer 910 that becomes a light emitting portion, and a first electrode 911 made of a reflective material are sequentially stacked on one surface of the counter substrate 901. Is done. The insulating layer 909 is provided to avoid an electrical short circuit between the first electrode and the second electrode.

  A passivation layer 912 is provided over the first electrode 911 for the purpose of preventing adverse effects of moisture and oxygen on the EL layer. Further on this, a protective film 913 protects the light source section. The passivation layer 912 and the protective film 913 may be attached as necessary.

  In addition, a selective reflection structure 914 is formed on the other surface of the counter substrate in substantially the same region as the emission surface from which light emitted from the light emitting unit is extracted from the second electrode. Here, the selective reflection structure 914 is a combination of a λ / 4 retardation plate 915 and a reflective polarizing plate 916.

  In the liquid crystal panel, since the uniformity of the cell gap in the pixel portion 903 is important, the flatness is particularly required in this display region on the counter substrate side. For this reason, a planarizing film 917 is formed on the selective reflection structure 914.

  Further, in this embodiment mode, a black matrix (hereinafter referred to as BM) 918, a color filter 919, and an overcoat 920 are sequentially formed on the planarizing film 917 as a configuration of a liquid crystal panel capable of color display. Here, the overcoat 920 has the purpose of preventing the BM 918 and the diffused material from the color filter 917 from adversely affecting the liquid crystal and the elements on the element substrate, in addition to the planarization action. On this overcoat 920, a translucent conductive film to be a counter electrode 921 for liquid crystal is formed.

  On the other hand, on the element substrate 900, a pixel portion 903 is configured by a pixel TFT 923, an auxiliary capacitor 924, and a pixel electrode 925 made of a light-transmitting conductive film, and a source driver circuit 905 is formed by a thin film transistor made of a circuit TFT 926 or the like. . Similarly, although not shown in this section, a gate driver circuit 904 made of a thin film transistor or the like is also configured. The source driver circuit 905 and the gate driver circuit 904 are connected to the FPC 906 through a terminal lead wiring 927 of the terminal portion 928, and various power supplies and signals are applied.

  In the present embodiment, a first electrode extraction portion 929 that is electrically connected to the first electrode 911 outside the counter substrate 901 when the panel is formed, and a second electrode extraction portion 930 that is electrically connected to the second electrode 908. Will be placed.

Normally, the first electrode extraction portion 929 is also formed simultaneously with the formation of the first electrode 911, and the second electrode extraction portion 930 is formed simultaneously with the formation of the second electrode 908.

The second electrode and the second electrode lead-out portion are formed of a light-transmitting conductive material such as ITO or ZnO. These films have higher electrical resistance than a metal material. In addition, it is not desirable in terms of reliability to treat these translucent conductive films as they are as they are. Further, when direct soldering or the like is performed, there is a problem that a special soldering device or material is required.

In the present embodiment, the first electrode forming film made of a metal material such as aluminum or aluminum alloy is formed on the second electrode extraction portion 930 formed in advance at the same time as the first electrode 911 is formed with the first electrode. Is structured to be electrically separated and stacked. Thereby, in the second electrode, the resistance of the second electrode extraction portion is reduced and the reliability is improved.

When the display surface of the liquid crystal panel is the front, the power supply connection portion is provided on the back surface of the panel.

Embodiments 1 to 6 show examples of structures that simultaneously realize extraction of polarized light while improving the extraction efficiency of emitted light from an illumination device (light source). However, a selective reflection structure is simply polarized. You may use the film | membrane or film of an effect | action equivalent to a board. Since there is no air layer between the light source and the polarizing plate, the optical interface loss during this period is improved.

  Alternatively, a polarizing plate (film) or the like is further arranged on the effective light emission side of the integrally mounted light source as in Embodiments 1 to 6, and the emission light passes through the transmission axis of the polarizing plate and the polarization plane of the emission light. It is possible to obtain a polarized light source with a better extinction ratio by adjusting the transmission. Thereby, the contrast of a liquid crystal display device etc. can be improved.

  Note that although the active matrix liquid crystal panel has been described in this embodiment, the present invention can also be applied to a passive matrix liquid crystal panel.

  In addition, it is desirable that the areas of the EL layers 809 and 910 serving as the light-emitting portions of the light sources be slightly larger than the areas of the pixel portions 803 and 903 shown in the fifth and sixth embodiments. However, increasing the size of the light emitting unit itself leads to an increase in power consumption. Furthermore, it is not desirable to irradiate unnecessary light to thin film transistors such as the circuit TFTs 824 and 926 constituting the source driver circuits 805 and 905 and the gate driver circuits 804 and 904 in view of the influence of light leakage. The present invention is also characterized in that the region of the light emitting portion can be selectively arranged according to each panel shape. That is, the EL layer may be selectively provided so as to overlap with the pixel region.

As an effect of the present embodiment, by using a surface light source, it is possible to use emitted light with little luminance unevenness without requiring a scattering optical system or the like. In addition, since the emitted light can be handled by the surface, it can be arranged in parallel plane at a distance that is very close to the next selective reflection structure, and it can be configured with a structure that is integrated with the light source without including an air layer. In addition, since the difference in refractive index can be reduced, a configuration with less interface loss can be obtained. Based on these characteristics, in addition to a single polarization component, a reflected light source can be converted and extracted so that a polarized light source with high light use efficiency can be configured.

Furthermore, since these functions can be incorporated on the same substrate, it can be used not only as a backlight source for liquid crystals but also as a counter substrate for liquid crystals, and a liquid crystal panel with a built-in backlight can be realized. It becomes.

With these effects, it is possible to realize a low-power consumption and thin panel of the liquid crystal panel.

(Embodiment 1)
The display device of the present invention can be used as a display unit of an electronic device.

An electronic device described in this embodiment includes the display device described in any of Embodiments 1 to 6. By using a polarized light source with improved light extraction efficiency, low power consumption can be realized. Further, by providing this light source on the counter substrate and mounting it integrally with the liquid crystal panel, the thickness of the panel and the light source (illuminating device) space required so far can be reduced. A thin and space-saving low power consumption liquid crystal display device can be realized.

Electronic devices manufactured by applying the present invention include cameras such as video cameras and digital cameras, goggle-type displays, navigation systems, sound playback devices (car audio, audio components, etc.), computers, game devices, portable information terminals ( Display capable of playing back a recording medium such as a mobile computer, a mobile phone, a portable game machine, or an electronic book) and an image playback apparatus (specifically, Digital Versatile Disc (DVD)) provided with a recording medium and displaying the image And the like). Specific examples of these electronic devices are shown in FIGS.

FIG. 11A illustrates a television device according to the present invention, which includes a housing 9101, a supporting base 9102, a display portion 9103, a speaker portion 9104, a video input terminal 9105, and the like. In this television device, the display device of the present invention can be used for the display portion 9103. By using a polarized light source with improved light extraction efficiency, the power consumption of the television device main body can be reduced. As a result, the product can be adapted to the living environment.

FIG. 11B illustrates a computer according to the present invention, which includes a main body 9201, a housing 9202, a display portion 9203, a keyboard 9204, an external connection port 9205, a pointing device 9206, and the like. In this computer, the display portion 9203 can use the display device of the present invention. By using a polarized light source with improved light extraction efficiency, low power consumption of the computer itself can be achieved.

  FIG. 11C illustrates a mobile phone, which includes a main body 9401, a housing 9402, a display portion 9403, an audio input portion 9404, an audio output portion 9405, operation keys 9406, an external connection port 9407, an antenna 9408, and the like. In this mobile phone, the display portion 9403 can use the display device of the present invention. Since a polarized light source with improved light extraction efficiency is used, the power consumption of the cellular phone can be reduced and the convenience can be improved.

  FIG. 11D illustrates a camera, which includes a main body 9501, a display portion 9502, a housing 9503, an external connection port 9504, a remote control receiving portion 9505, an image receiving portion 9506, a battery 9507, an audio input portion 9508, operation keys 9509, and an eyepiece portion. 9510 etc. are included. In this camera, the display portion 9502 can use the display device of the present invention. Since a polarized light source with improved light extraction efficiency is used, the power consumption of the camera body can be reduced, and the convenience can be improved.

  As described above, the display device of the present invention has a very wide application range, and can be applied to electronic devices in various fields. By applying the present invention, a thin and space-saving electronic device with low power consumption can be manufactured.

(Embodiment 2)
The display device of the present invention can also be used as a lighting device. One mode of using a display device to which the present invention is applied as a lighting device will be described with reference to FIGS.

Further, it can be used as a headlight for automobiles, bicycles, ships, and the like. FIG. 12 shows an example in which a display device to which the present invention is applied is used as a headlight of an automobile. FIG. 12B is an enlarged cross-sectional view of the headlight 1000 of FIG. In FIG. 12B, the display device of the present invention is used as the light source 1011. Light emitted from the light source 1011 is reflected by the reflecting plate 1012 and extracted to the outside. As shown in FIG. 12B, light with higher luminance can be obtained by using a plurality of light sources. FIG. 12C shows an example in which the display device of the present invention manufactured in a cylindrical shape is used as a light source. Light emitted from the light source 1021 is reflected by the reflecting plate 1022 and extracted outside.

FIG. 13 shows an example in which the display device to which the present invention is applied is used as a table lamp which is a lighting device. A table lamp illustrated in FIG. 13 includes a housing 2101 and a light source 2102, and the display device of the present invention is used as the light source 2102. Since the display device of the present invention is thin and space-saving, there is a high degree of freedom in the installation location indoors.

FIG. 14 shows an example in which a display device to which the present invention is applied is used as an indoor lighting device 3001. Since the display device of the present invention can have a large area, the display device can be used as a large-area lighting device. In addition, since the display device of the present invention is thin and has low power consumption, it can be used as a lighting device with low thickness and low power consumption. As described above, the television set 3002 according to the present invention as described with reference to FIG. 11A is installed in a room in which the display device to which the present invention is applied is used as the indoor lighting device 3001, and public broadcasting or You can watch movies. In such a case, since both devices have low power consumption, powerful images can be viewed in a bright room without worrying about electricity charges.

The lighting device is not limited to those illustrated in FIGS. 12, 13, and 14, and can be applied as various types of lighting devices including lighting of houses and public facilities. In such a case, since the illuminating device according to the present invention has a thin light-emitting medium and thus has a high degree of design freedom, it is possible to provide products with various designs on the market.

As described above, the display device of the present invention can provide a thin, space-saving electronic device with lower power consumption. This embodiment mode can be freely combined with the above embodiment modes.

The figure explaining the illuminating device of this invention. The figure explaining the illuminating device of this invention. The figure explaining the illuminating device of this invention. The figure explaining the illuminating device of this invention. The figure explaining the illuminating device of this invention. The figure explaining the illuminating device of this invention. The figure explaining the illuminating device of this invention. The figure explaining the illuminating device of this invention. 4A and 4B illustrate a liquid crystal display device of the present invention. 4A and 4B illustrate a liquid crystal display device of the present invention. 8A and 8B each illustrate an electronic device of the invention. The figure explaining the illuminating device of this invention. The figure explaining the illuminating device of this invention. The figure explaining the illuminating device of this invention.

Claims (17)

A first electrode made of a reflective material, an EL layer, and a second electrode made of a translucent conductive film;
Light emitted from the EL layer is extracted from the second electrode;
On the side of the second electrode from which light is extracted, a selective reflection structure is provided without interposing an air layer,
The selective reflection structure has a function of transmitting light of a specific polarization component and reflecting other light. A first electrode, an EL layer, and a second electrode are stacked on the substrate in this order.
The first electrode is made of a reflective material,
The second electrode is made of a light-transmitting material,
Light emitted from the EL layer is extracted from the second electrode;
On the side of the second electrode from which light is extracted, a selective reflection structure is provided without interposing an air layer,
The selective reflection structure has a function of transmitting light of a specific polarization component and reflecting other light. On one surface of a substrate made of a light-transmitting material, a second electrode made of a light-transmitting material, an EL layer, and a first electrode made of a reflective material are laminated in this order.
A selective reflection structure is provided on the other surface of the substrate,
Light emitted from the EL layer is extracted from the second electrode;
The light extracted from the second electrode is incident on the selective reflection structure through the substrate without interposing an air layer;
The selective reflection structure has a function of transmitting light of a specific polarization component in incident light and reflecting other light. On one surface of a substrate made of a light-transmitting material, a second electrode made of a light-transmitting material, an EL layer, and a first electrode made of a reflective material are laminated in this order.
The other surface of the substrate is provided in contact with an adhesive layer,
A selective reflection structure is provided in contact with the adhesive layer,
Light emitted from the EL layer is extracted from the second electrode;
The light extracted from the second electrode is incident on the selective reflection structure through the substrate and the adhesive layer,
The selective reflection structure has a function of transmitting light of a specific polarization component in incident light and reflecting other light. 5. The optical configuration according to claim 1, wherein the selective reflection structure is combined with a polarizing beam splitter function configured to transmit a P wave and reflect an S wave toward the first electrode. An illumination device comprising a body. 5. The selective reflection structure according to claim 1, wherein the selective reflection structure combines a plurality of polarization beam splitter functions configured to transmit a P wave and reflect an S wave to the first electrode side. An illumination device comprising an optical structure. 5. The selective reflection structure according to claim 1, wherein the selective reflection structure transmits a circularly polarized component in a specific rotation direction in incident light, and converts the transmitted circularly polarized component light into linearly polarized light. The illumination device has a reflective polarization function configured to reflect the light of other components toward the first electrode side.   The lighting device according to claim 1, wherein the selective reflection structure is combined with a retardation plate.   9. The lighting device according to claim 1, further comprising a scattering layer between the second electrode and the selective reflection structure. A liquid crystal is sandwiched between a pair of substrates, a pixel electrode made of a transparent photoconductive film disposed in a matrix on one of the pair of substrates, and a semiconductor element connected to the pixel electrode are formed,
The one substrate is a substrate having translucency and insulation,
The other substrate has a first electrode made of a reflective material, an EL layer, a second electrode made of a translucent conductive film, and a selective reflection structure.
Light emitted from the EL layer is extracted from the second electrode, and the selective reflection structure is provided on the side from which the light is extracted from the second electrode without an air layer interposed. A liquid crystal display device. A liquid crystal is sandwiched between a pair of substrates, a pixel electrode made of a transparent photoconductive film disposed in a matrix on one of the pair of substrates, and a semiconductor element connected to the pixel electrode are formed,
The one substrate is a substrate having translucency and insulation,
The other substrate has a selective reflection structure on a surface facing the pixel electrode,
A second electrode made of a translucent conductive film, an EL layer, and a first electrode made of a reflective material are sequentially stacked on the back surface of the other substrate,
2. The liquid crystal display device according to claim 1, wherein the other substrate has translucency and insulation. A liquid crystal is sandwiched between a pair of substrates, a pixel electrode made of a transparent photoconductive film disposed in a matrix on one of the pair of substrates, and a semiconductor element connected to the pixel electrode are formed,
The one substrate is a substrate having translucency and insulation,
The other substrate is provided with an adhesive layer in contact with the surface facing the pixel electrode,
A selective reflection structure in contact with the adhesive layer;
A second electrode made of a translucent conductive film, an EL layer, and a first electrode made of a reflective material are sequentially stacked on the back surface of the other substrate,
2. The liquid crystal display device according to claim 1, wherein the other substrate has translucency and insulation. 13. The optical configuration according to claim 10, wherein the selective reflection structure is combined with a polarizing beam splitter function configured to transmit a P wave and reflect an S wave toward the first electrode. A liquid crystal display device comprising a body. 13. The selective reflection structure according to claim 10, wherein the selective reflection structure transmits circularly polarized light components in a specific rotation direction of incident light and converts the transmitted circularly polarized light components into linearly polarized light. A liquid crystal display device having a reflective polarizing function configured to reflect a light of a component other than that to the first electrode side.   The liquid crystal display device according to claim 10, wherein the selective reflection structure is combined with a retardation plate.   16. The liquid crystal display device according to claim 10, further comprising a scattering layer between the second electrode and the selective reflection structure. 17. The liquid crystal display device according to claim 10, wherein the EL layer is selectively provided so as to overlap with a pixel region.

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