JP4771040B2 - EL lighting device - Google Patents

Description

  The present invention relates to an EL lighting device using an electroluminescent element (hereinafter referred to as an EL element).

Conventionally, such an EL lighting device is disclosed in Patent Documents 1 to 3, for example.
First, according to Patent Document 1, as shown in FIG. 26, an organic EL light-emitting device 1 as an EL lighting device includes a hole injection layer 2b separated from each other by an insulator rib 3 on a transparent electrode 2a. , A plurality of EL elements 2 each composed of a light emitting layer 2c and a counter electrode 2d, and a transparent electrode 2a and a translucent substrate 4 disposed therebelow so as to face each EL element 2. The condensing lens 5 is arranged. Here, the condensing lens 5 includes individual lens portions 5a that face the corresponding EL elements 2 in a plan view in a one-to-one manner.

  According to the EL illumination device 1 having such a configuration, the light emitted from the light emitting layer 2c in each EL element 2 travels downward and the corresponding lens portion of the condenser lens 5 via the transparent electrode 2a. The light enters the lens 5a, is condensed in a predetermined angle range by the lens unit 5a, and is emitted downward.

  Further, according to Patent Document 2, as shown in FIG. 27, the organic EL light emitting element 6 as an EL lighting device is similarly positively separated from each other by a separation film (insulator rib) 3 on a transparent electrode 2a. A plurality of EL elements 2 comprising a hole injection layer 2b, a light emitting layer 2c and a counter electrode 2d; and a light angle conversion means 7 provided on the upper surface of the translucent substrate 4 disposed below the transparent electrode 2a. It is configured. Here, a plurality of light angle conversion means 7 are provided for each EL element 2.

  According to the EL lighting device having such a configuration, the light emitted from the light emitting layer 2c in each EL element 2 travels downward and is transmitted through the transparent electrode 2a and the light angle conversion means 7. Incident on the conductive substrate 4. At that time, the light emitted from each EL element 2 is incident on a plurality of corresponding light angle conversion means 7, and is condensed in a predetermined angle range by these light angle conversion means 7, and is directed downward. It will be emitted toward.

  Further, according to Patent Document 3, as shown in FIG. 28, the organic electroluminescent element 8 as an EL lighting device directly constitutes a plurality of organic electroluminescent elements 2 on a translucent substrate 4. The transparent substrate 4 is constructed by using a plastic microlens array having a microlens portion 4a having a circular arc cross section on the lower surface.

According to the EL illumination device having such a configuration, the light emitted from each EL element 2 enters the translucent substrate 4. At this time, when the light emitted from each EL element 2 is emitted downward from the lower surface of the translucent substrate 4, the light enters the corresponding one or a plurality of minute lens portions 4 a, thereby the minute lens. The light is condensed in a predetermined angle range by the portion 4a and emitted downward.
Japanese Patent Laid-Open No. 10-172756 JP 2002-260845 A Japanese Patent Laid-Open No. 10-223367

However, each of the EL lighting devices described above has the following problems. In other words, in the EL lighting device 1 according to Patent Document 1, since each EL element 2 is a surface light source, there is light that cannot be condensed by the lens portion 5a of the condenser lens 5 and diffuses. Therefore, according to the example in Patent Document 1, the luminance improvement rate is limited to 2.1 to 2.5 times.
Moreover, it is thought that each lens part 5a of the condensing lens 5 has the same directivity characteristic about an up-down and left-right direction in planar view from the shape and arrangement | positioning. For this reason, when different directional characteristics are required in the vertical and horizontal directions, such a request cannot be met.

In the EL illumination device 6 according to Patent Document 2, the light angle conversion means 7 is constituted by a minute lens so that it is one-to-many with respect to the EL elements that are light sources. There is light that is diffused without being collected even by the microlenses. For this reason, according to the Example shown by patent document 2, the brightness | luminance improvement rate will remain only 1.7 times at the maximum.
In addition, it is theoretically possible to design each individual microlens with its own parameters such as curvature so that each lens has the maximum light collection efficiency. Creating a lens is practically difficult and impractical.

  In the EL illumination device according to Patent Document 3, since the individual microlens portions 4a of the microlens array can be condensed relatively efficiently, the luminance improvement rate is about four times. It is necessary to accurately align the individual microlens portions 4a and the individual EL elements 2, and when the microlenses having a circular arc cross section are arranged on a plane, it is necessary to perform alignment in two vertical and horizontal directions. Assembling work becomes difficult.

On the other hand, in order to facilitate the assembling work, the radius of each microlens portion 4a may be increased and the interval between the individual EL elements 2 may be widened. The lens thickness increases in accordance with the distance between the EL elements 2. Therefore, the thickness of the translucent substrate 4 increases, and the entire EL lighting device becomes thick. For example, according to the conventional example of Patent Document 3, the thickness of the translucent substrate is about 1 mm.
On the other hand, if the distance between the microlens portions 4a is made smaller than the interval between the EL elements 2 in order to keep the thickness of the translucent substrate thin, the light collection effect by the individual microlens portions 4a is reduced, and the luminance is improved. The rate becomes about 1.14 to 1.50 times.

Further, since the microlens portions 4a having a circular arc cross section are arranged on a plane, the far field directivity is considered to be the same in the vertical and horizontal directions.
Accordingly, in the same way, when different directivity characteristics are required in the vertical and horizontal directions, such a request cannot be met.

  In view of the above, an object of the present invention is to provide an EL illumination device that has a simple and thin configuration, improves on-axis luminance, and has different directivity characteristics depending on directions.

According to the configuration of the present invention, an object of the present invention is an EL illumination device including a flat transparent substrate and an EL element arranged so that the light emission side faces the one surface of the transparent substrate. And
The EL element is divided into a light emitting portion and a non-light emitting portion at a predetermined pitch in one direction on the light emitting surface,
The transparent substrate is, on the exit surface opposite to the above EL device, light emission from the first light angle converting means by the prism made of a non-emitting portion corresponds to a region convex or concave triangular cross section of the EL element It has a flat portion in the portion corresponding to the part area, further than the refractive index of the transparent substrate that is filled in a groove provided in correspondence with the non-light emitting region of the EL element at the incident surface characterized in that it comprises a second optical angle converter constructed by a transparent material composed of a low refractive index material of lower refractive index, the EL lighting device is achieved.

  In the EL lighting device according to the present invention, preferably, the EL element is divided into a light emitting portion and a non-light emitting portion at a predetermined pitch in a direction perpendicular to the one direction.

  In the EL illumination device according to the present invention, preferably, the prisms are arranged in a double row.

  In the EL illumination device according to the present invention, preferably, the groove is a one-dimensional groove provided on the incident surface side of the transparent substrate corresponding to the non-light emitting portion region of the EL element.

  In the EL illumination device according to the present invention, preferably, the groove is a two-dimensional groove provided on the incident surface side of the transparent substrate corresponding to the non-light emitting portion region of the EL element.

The EL illumination device according to the present invention is preferably an EL illumination device comprising a flat transparent substrate and an EL element arranged so that the light emission side faces the one surface of the transparent substrate. ,
The EL element is divided into a light emitting portion and a non-light emitting portion at a predetermined pitch in two directions perpendicular to the light emitting surface,
The transparent substrate includes a first prism formed of a convex or concave frustoconical horn having a circular bottom surface centered on the center of the light emitting portion of the EL element on an emission surface opposite to the EL element. The light angle conversion means and the light emitting part region have a flat part corresponding to the light emitting part region, and correspond to the cylindrical part and the non-light emitting part region provided on the incident surface corresponding to the light emitting part region of the EL element. and a groove provided in the second light angle converting means constituted by a transparent material composed of a low refractive index material of refractive index lower than the refractive index of the transparent substrate that is filled in the trench It is achieved by an EL lighting device characterized by comprising:

In the EL illumination device according to the present invention, preferably, the groove is a two-dimensional groove provided on the incident surface side of the transparent substrate corresponding to the non-light emitting portion region of the EL element, and the light emitting portion region of the EL element. It is formed by cutting out so as to leave the cylindrical portion corresponding to.

According to the said structure, the light radiate | emitted from the light emission part of EL element injects into a transparent substrate. At that time, the light from the EL element is incident on the transparent substrate made of a high refractive index material in the light emitting part region of the transparent substrate, and then guided to the emission side to form a flat surface formed on the emission side of the transparent substrate. To the outside.
The light emitted from the light emitting part of the EL element and reaching the emission surface corresponding to the non-light emitting part region of the transparent substrate is effectively predetermined by changing the light angle by the first light angle converting means. By guiding within the angular range, a predetermined directivity can be obtained, and the on-axis luminance can be improved.

Accordingly, the light extraction efficiency from the EL element is improved, and the transparent substrate having the first light angle conversion means on the emission side without providing a convex lens portion protruding from the surface of the transparent substrate as in the prior art. By using the first light angle conversion means to effectively guide the light from the EL element into a predetermined angle range, predetermined directivity can be obtained and on-axis luminance can be improved. become.
Moreover, when the EL element includes the light emitting part and the non-light emitting part at a predetermined pitch in one direction, the light emitting part is configured in a stripe shape. Therefore, when combining with the transparent substrate, the alignment can be easily performed by performing alignment in only one direction, and the assembly can be easily performed.

  When the EL element is divided into a light emitting part and a non-light emitting part at a predetermined pitch in the direction perpendicular to the one direction, the non-light emitting part is configured in a lattice shape.

  When the first light angle conversion means is composed of a prism, the first light angle conversion means can be easily formed on the exit surface of the transparent substrate.

  When the prism is formed in a convex cross-sectional triangle shape, the first light angle conversion means can be easily formed on the emission surface of the transparent substrate, and the light emitted from the prism shape can be reliably It will be guided within a predetermined angle range.

  When the prism is formed in a concave triangular cross section, the first light angle conversion means can be easily formed on the exit surface of the transparent substrate, and the first light angle conversion means is the transparent substrate. Therefore, the transparent substrate and the EL lighting device can be made thin.

  When the prism shape is double-rowed, the height of the first light angle conversion means is suppressed, and in particular in the case of a convex shape, the transparent substrate and the EL lighting device are configured to be thin. Will be able to.

  When the prism is formed as a frustoconical horn with a circular bottom centered on the center of the light emitting part of the EL element, the EL element has a lattice shape when the non-light emitting part area is a lattice. The first light formed as a convex or concave frustoconical horn is formed by the light incident on the first light angle conversion means at the emission surface of the transparent substrate from all the light emitting portions of the element. The light angle is converted by the prism of the light angle conversion means and guided to the outside within a predetermined angle range, so that the light extraction efficiency from the EL element is further improved.

  When the transparent substrate includes a second light angle conversion means on the incident surface corresponding to the non-light emitting portion region of the EL element, the light emitting portion of the EL element is compared with the inside of the transparent substrate. Light incident at a large incident angle and entering the non-light emitting area near the incident surface of the transparent substrate is again guided into the light emitting area by the second light angle conversion means, and is emitted from the emitting surface of the transparent substrate to the outside. Since the light is emitted, the light extraction efficiency from the EL element is further improved.

  A low refractive index in which the second light angle conversion means is filled in a groove, that is, a one-dimensional groove or a two-dimensional groove provided corresponding to the non-light emitting portion region of the EL element on the incident surface side of the transparent substrate. In the case of a transparent material made of a material, a groove is formed in a striped pattern or a lattice pattern on the surface on the flat incident surface side of the transparent substrate, and a low refractive index material is filled in the groove. Thus, the second light angle conversion means can be easily configured.

  When the two-dimensional groove is formed by cutting out so as to leave a cylindrical portion corresponding to the light emitting portion region of the EL element, when the non-light emitting portion region of the EL element is in a lattice shape, When light incident on the incident surface of the transparent substrate from each light emitting portion of the EL element with a relatively large incident angle in all radial directions enters the non-light emitting portion region near the incident surface of the transparent substrate, the second light angle Since the light is again guided into the light emitting portion region by the conversion means and is emitted to the outside from the emission surface of the transparent substrate, the light extraction efficiency from the EL element is further improved.

For the first light angle conversion means arranged at a predetermined pitch with respect to one direction, a prism sheet composed of prisms arranged in a direction perpendicular to the one direction is arranged to face the emission surface of the transparent substrate. The first light angle conversion means converts the light angle from the EL element with respect to one direction, and the prism sheet disposed opposite to the emission surface of the transparent substrate defines the one direction. The light angle can be converted in the vertical direction. As a result, the EL element and the transparent substrate can be aligned only in one direction, and light angle conversion in two directions can be performed.
Since different light angle adjustment means are used in one direction (left and right direction) in which the light angle is adjusted by the first light angle conversion means and in the direction (up and down direction) in which the light angle is adjusted by the prism sheet, Field directivity can be imparted.

  In the case where a reflection layer is provided in the non-light emitting portion region on the emission surface side of the EL element, the reflection layer reflects the light returned from the prism sheet or the first light angle means. By returning to the substrate exit surface, the light extraction efficiency can be improved by increasing the amount of light reaching the exit surface of the transparent substrate from the EL element by the so-called light recycling effect.

  When the reflective layer is made of a conductive material and is electrically connected to the transparent electrode of the EL element, the reflective layer acts as an auxiliary electrode of the transparent electrode, and the EL element The electrical element efficiency can be improved.

Thus, according to the present invention, directivity is imparted to the emitted light by providing the light angle conversion means on the exit surface and / or the entrance surface in the non-light emitting portion region of the transparent substrate with a simple configuration. Thus, the on-axis brightness can be improved.
Further, the light emitting part region of the EL element and the first or second light angle conversion means of the transparent substrate are configured in a striped shape only in one direction, and more preferably, a prism sheet is disposed facing the emission surface of the transparent substrate. This makes it possible to provide different far-field directional characteristics in the vertical and horizontal directions in a plan view, for example, with a narrow viewing angle in the horizontal direction suitable for a backlight of a liquid crystal display in various portable devices and a relatively wide vertical direction. An illumination device having a viewing angle can be realized.

  Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to FIGS. The embodiments described below are preferable specific examples of the present invention, and thus various technically preferable limitations are given. However, the scope of the present invention particularly limits the present invention in the following description. As long as there is no description of the effect, it is not restricted to these aspects.

1 to 3 show a configuration of a first embodiment of an EL lighting device according to the present invention.
1 and 2, the EL lighting device 10 includes an EL element 11 and a flat transparent substrate 20 disposed below the EL element 11.

  The EL element 11 has a known configuration, and includes a light emitting layer 12, a metal electrode 13 provided on the upper side of the light emitting layer 12, and a transparent electrode 14 provided on the lower side of the light emitting layer 12. ing.

On the upper surface of the transparent electrode 14, a lattice-like insulation is patterned at a predetermined pitch so as to be orthogonal to each other in two vertical and horizontal directions in a plan view (that is, in a direction perpendicular to the paper surface and in a horizontal direction in FIG. 1). A membrane 15 is arranged. Thus, the lower surface of the light emitting layer 12 is partitioned by the insulating film 15, thereby having a plurality of square (in the illustrated case, square) light emitting portions 12 a arranged in a dot matrix, for example.
In addition, the shape of the light emission part 12a is not restricted to a square, A rectangle may be sufficient and other shapes, such as circular, may be sufficient.

The metal electrode 13 is configured as a cathode, and reflects light emitted upward from the light emitting layer 12 of the EL element 11 downward.
The transparent electrode 14 is configured, for example, as an anode made of an ITO film so as to transmit light emitted downward from the light emitting layer 12 of the EL element 11 and light reflected downward by the metal electrode 13. It has become.

  Here, in the EL element 11, for example, the thickness of the light emitting layer 12 is 0.2 μm, the thickness of the transparent electrode 14 is 0.2 μm, the vertical and horizontal pitches of the light emitting portions 12a are 0.2 mm, and the insulating film 15 Is selected to be 0.1 mm.

  As shown in FIG. 1, the transparent substrate 20 is made of a transparent material having a predetermined thickness, and the lattice-like insulating film is formed on a surface 21 on the EL element 11 side (hereinafter referred to as an incident side). 15 is provided with a groove (two-dimensional groove) 22 extending in two vertical and horizontal directions in a region (hereinafter referred to as a non-light-emitting portion region) facing 15, and on the side opposite to the incident side surface of the transparent substrate 20 (hereinafter referred to as Similarly, a prism portion 24 is provided in a non-light emitting portion region facing the lattice-like insulating film 15 on the surface 23 on the emission side.

The two-dimensional groove 22 has a substantially rectangular cross section, but may have a taper of, for example, about 5 degrees in consideration of die cutting during molding.
The two-dimensional groove 22 is filled with a transparent material 25 having a refractive index lower than that of the transparent material constituting the transparent substrate 20.

The prism portion 24 has a triangular cross section so as to protrude downward from the surface 23 on the emission side of the transparent substrate 20.
As a result, the prism portion 24 has a portion corresponding to the non-light emitting portion region formed as an inclined surface as a prism shape, and a portion corresponding to the light emitting portion region is formed flat and parallel to the incident surface.

  Here, the transparent substrate 20 has, for example, a thickness of 0.5 mm, a depth of the two-dimensional groove 22 of 0.1 mm, a refractive index of the transparent substrate 20 of 1.6, and a refractive index of the transparent material 25 of 1.5. The apex angle of the prism portion 24 is selected to be 60 to 130 degrees.

  Further, the transparent substrate 20 is formed on a surface on the incident side by molding with a mold formed corresponding to the shape of the two-dimensional groove 22 and the prism portion 24, for example, or with respect to a flat substrate material. After forming the two-dimensional groove 22 and / or the prism portion 24 by cutting, laser processing, or the like, the two-dimensional groove 22 is filled with a transparent material 25 such as a photo-curing resin whose refractive index is adjusted. It can be produced by removing the transparent material 25 protruding from the surface and flattening the incident-side surface.

The EL lighting device 10 according to the embodiment of the present invention is configured as described above, and the light emitted from the light emitting layer 12 of the EL element 11 passes through the region of the light emitting unit 12a defined by the insulating film 15 and EL. The light exits below the element 11 and enters the transparent substrate 20.
Here, the light incident on the transparent substrate 20 from the EL element 11 enters the transparent substrate 20 made of a high refractive index material in the region immediately below the light emitting portion 12a (hereinafter referred to as the light emitting portion region), and then exits. Then, the light is emitted to the outside from the emission side of the transparent substrate 20.
At that time, light incident on the transparent substrate 20 at a relatively large incident angle enters the side surface in the two-dimensional groove 22 around the light emitting portion region in the transparent substrate 20, and the low refractive index in the two-dimensional groove 22. The light angle is adjusted by reflection based on the difference in refractive index between the transparent material 25 and the high refractive index material constituting the transparent substrate 20, and the light is guided to the lower surface of the transparent substrate 20.

The light that has entered the transparent substrate 20 at a relatively small angle enters the flat portion of the substrate emission surface at a small angle, and substantially exits in a substantially vertical axial direction downward in FIG.
On the other hand, light incident on the transparent substrate 20 at a relatively large incident angle also enters the non-light emitting region, that is, the prism portion 24 on the lower surface of the transparent substrate 20. Here, since the light incident on the prism portion 24 is incident on the inclined surface of the prism portion 24, the incident angle with respect to the prism portion 24 is reduced, and is not totally reflected by the inner surface of the prism portion 24. The light angle is adjusted and emitted to the outside.

  Therefore, the light emitted from the light emitting layer 12 of the EL element 11 enters the transparent substrate 20 from the light emitting portion 12a defined by the insulating film 15, and is filled in the two-dimensional groove 22 on the incident surface side. By adjusting the light angle by the boundary surface with the transparent material 25 having the refractive index and adjusting the light angle by the prism portion 24 on the exit surface side, the light is emitted from the surface on the exit surface side of the transparent substrate 20 with high efficiency and small. By emitting at the emission angle, the on-axis luminance is improved.

  Thus, according to the EL illumination device 10 according to the embodiment of the present invention, the EL element 11 defines each light emitting portion 12a by the grid-like insulating film 15, and the transparent substrate 20 is on the incident surface side and the output surface side. Each having a two-dimensional groove 22 as a light angle adjusting means, a transparent material 25, and a prism portion 24, so that light from each light emitting portion 12a of the EL element 11 can be efficiently taken out with a simple configuration. On-axis brightness can be improved by adjusting the light angle by the low refractive index transparent material 25 and the prism portion 24 filled in the two-dimensional groove 22 of the transparent substrate 20.

Then, when the simulation of the EL illumination device 10 was performed, as shown in FIG. 3, a simulation result of the total luminous flux indicated by the symbol A and the on-axis luminance effect indicated by the symbol B was obtained.
That is, FIG. 3 shows the total luminous flux and the on-axis luminance effect when the apex angle θ of the prism portion 24 is changed from 70 to 130 degrees. Here, the total luminous flux A and the on-axis luminance effect B are the multiples of the total luminous flux and the on-axis luminance when the same emission energy is applied as in the conventional EL lighting device using the flat transparent substrate without the insulating film 15 formed. It represents.

According to this simulation result, the total luminous flux A is about 1.2 times, and when the apex angle θ of the prism portion 24 is 105 degrees, the on-axis luminance effect B is about 3.3 times the maximum.
Therefore, if the ratio of the light emission energy in the light emitting layer 12 to the internal light emission efficiency, that is, the power consumption in the EL element is the same as that of the conventional EL lighting device, the embodiment of the present invention is compared with the conventional EL lighting device. According to the EL illumination device 10, the light extraction efficiency is improved by about 1.2 times the total luminous flux, and the on-axis luminance can be improved by 3.3 times. Thereby, in order to obtain the same on-axis luminance, power consumption of 1 / 3.3 times is sufficient.

4 to 6 show the configuration of the second embodiment of the EL lighting device according to the present invention.
4 and 5, the EL illumination device 30 has a prism portion 31 formed on the surface of the transparent substrate 20 on the emission side as compared with the EL illumination device 10 shown in FIG. It has a different configuration only in that it is formed in a triangular shape with a concave shape of 150 to 150 degrees.
The EL illumination device 30 is otherwise identical in structure to the EL illumination device 10 shown in FIG.

In the EL lighting device 30 having such a configuration, the on-axis luminance can be improved by acting in the same manner as the EL lighting device 10 shown in FIG.
At that time, the light incident on the transparent substrate 20 at a relatively large incident angle similarly enters the non-light emitting portion region, that is, the prism portion 31 on the lower surface of the transparent substrate 20. Here, since the light incident on the prism portion 31 is incident on the inclined surface of the prism portion 31, the incident angle with respect to the prism portion 31 is reduced, and is not totally reflected by the inner surface of the prism portion 31, The light angle is adjusted and emitted to the outside.

  Then, with respect to the EL illumination device 30, as in the EL illumination device 10 shown in FIGS. 1 and 2, a simulation was performed when the apex angle θ of the prism portion 31 was changed from 60 to 150 degrees. As shown in FIG. 6, simulation results of the total luminous flux A and the on-axis luminance effect B were obtained.

According to this simulation result, the total luminous flux A is about 1.2 times, and when the apex angle θ of the prism portion 24 is 120 degrees, the on-axis luminance effect B is about 3.03 times the maximum.
Therefore, if the ratio of the light emission energy in the light emitting layer 12 to the internal light emission efficiency, that is, power consumption, in the conventional EL lighting device and the EL element is constant, the embodiment of the present invention is compared with the conventional EL lighting device. According to the EL illumination device 30, the total light flux is about 1.2 times, so that the light extraction efficiency is improved and the on-axis luminance can be improved to 3.0 times. Thereby, in order to obtain the same on-axis luminance, power consumption of 1 / 3.0 times is sufficient.

7 to 9 show the configuration of the third embodiment of the EL lighting device according to the present invention.
7 and 8, the EL illumination device 40 is different from the EL illumination device 10 shown in FIG. 1 in that the EL element 11 is replaced with the prism portion 24 formed on the surface on the emission side of the transparent substrate 20. Corresponding to the light emitting part 12a, as a light angle conversion means, for example, a frustoconical horn part 41 that expands downward in a concave shape with an inclination angle of 30 to 75 degrees is provided, and the surface on the incident side of the transparent substrate 20 Instead of the two-dimensional groove 22 formed in FIG. 2, a groove portion is provided around the cylindrical portion 42 so as to leave a cylindrical portion 42 corresponding to the light emitting portion 12a, and further, instead of the insulating film 15 of the EL element 11. For example, the structure is different in that an insulating film 43 including circular holes defining a circular light emitting portion 12a having a diameter of 0.16 mm, for example, is provided at a pitch of 0.2 mm.

Accordingly, the cylindrical portion 42 on the incident surface side of the transparent substrate 20 and the truncated cone-shaped horn portion 41 are concentrically arranged corresponding to the circular light emitting portion 12 a defined by the insulating film 43.
Here, in each horn part 41, the diameter of the surface 23 on the EL element 11 side is selected to be approximately the same as that of the light emitting part 12a and the cylindrical hole 42. In addition, each horn portion 41 desirably has a tangent line between the adjacent horn portions 41 in the vertical and horizontal directions so that the diameter on the exit surface side is in contact with or overlaps with the adjacent horn portion 41. Is set.
The EL illumination device 40 is otherwise the same as the EL illumination device 10 shown in FIG.

In the EL lighting device 40 having such a configuration, the on-axis luminance can be improved by acting in the same manner as the EL lighting device 10 shown in FIG.
At that time, the light incident on the cylindrical portion 42 of the transparent substrate 20 with a relatively large incident angle similarly enters the peripheral surface of the horn portion 41 on the lower surface of the transparent substrate 20 with a relatively large incident angle. Become. Here, since the light incident on the peripheral portion of the horn part 41 is incident on the inclined surface around the horn part 42, the incident angle with respect to the horn part 41 is reduced, and total reflection is performed on the inner surface of the horn part 41. Instead, the light angle is converted and emitted to the outside.

  Then, with respect to the EL lighting device 40, as in the EL lighting device 10 shown in FIGS. 1 and 2, a simulation was performed when the inclination angle of the horn portion 41 was changed from 30 to 75 degrees. As shown in FIG. 5, simulation results of the total luminous flux A and the on-axis luminance effect B were obtained.

According to this simulation result, the total luminous flux A is about 1.1 times, and when the inclination angle of the horn portion 41 is 40 degrees, the on-axis luminance effect B is about 2.7 times the maximum.
Therefore, if the ratio of the light emission energy in the light emitting layer 12 to the internal light emission efficiency, that is, power consumption, in the conventional EL lighting device and the EL element is constant, the embodiment of the present invention is compared with the conventional EL lighting device. According to the EL illumination device 40, the light extraction efficiency is improved by about 1.1 times the total luminous flux, and the on-axis luminance can be improved by 2.7 times. Thus, in order to obtain the same on-axis luminance, power consumption of 1 / 2.7 times is sufficient.

10 to 14 show the configuration of the fourth embodiment of the EL lighting device according to the present invention.
10 and 11, the EL lighting device 50 is in one direction (in the direction perpendicular to the paper surface in FIG. 11) instead of the insulating film 15 of the EL element 11 as compared with the EL lighting device 10 shown in FIG. For example, an insulating film 51 having a pitch of 0.167 mm and a width of 0.125 mm is disposed to define a striped light-emitting portion 51a patterned only on the surface of the transparent substrate 20 on the incident side. Instead of the dimensional groove 22, a one-dimensional groove 52 is formed corresponding to the light emitting portion 51 a of the EL element 11 and should be filled with the low refractive index transparent material 25 that extends in only one direction.

On the other hand, a reflective film 53 is formed on the lower surface of the transparent electrode 14 of the EL element 11 in a region facing the insulating film 51. The reflection film 53 is made of, for example, a conductive metal, and preferably functions as an auxiliary electrode for the transparent electrode 14 by being electrically connected to the transparent electrode 14.
Further, instead of the prism portion 24, the surface on the emission side of the transparent substrate 20 is selected so as to protrude in a triangular shape extending in only one direction, for example, with an apex angle of 80 to 150 degrees and a width of 0.125 mm. A convex prism portion 54 is formed, and a prism 55a, for example, having an apex angle of 90 degrees extending in a direction perpendicular to the prism portion 54 so as to face the surface on the emission side of the transparent substrate 20 is formed at a pitch of 0.024 mm. The structure is different in that the provided prism sheet 55 having a thickness of 0.062 mm is disposed.
The EL illumination device 50 is otherwise the same as the EL illumination device 10 shown in FIG.

In the EL illumination device 50 having such a configuration, the on-axis luminance can be improved by acting in the same manner as the EL illumination device 10 shown in FIG.
Similarly, light incident at a relatively large incident angle in a direction perpendicular to the one direction with respect to the transparent substrate 20 is also incident on the non-light emitting portion region, that is, the prism portion 54 on the lower surface of the transparent substrate 20. become. Here, since the light incident on the prism portion 54 is incident on the inclined surface of the prism portion 54, the incident angle with respect to the prism portion 54 is reduced, and is not totally reflected by the inner surface of the prism portion 54. The light angle is adjusted and emitted to the outside.

  Further, the light incident on the transparent substrate 20 in the horizontal direction with respect to the one direction is emitted from the substrate without being converted by the first light angle conversion means, and is incident on the prism sheet 55. Of the light rays incident on the prism sheet 55, the light rays having a fixed angle condition are converted by the prism 55a and emitted to the outside, and the other light rays are reflected and returned to the EL element side. The reflected light beam is reflected again by the metal electrode or the reflective film, and so-called light recycling is performed by the prism sheet. In other words, the reflective film is inserted directly under the non-light-emitting part as a partially reflective layer in order to avoid light incident on the insulating film with a low transmittance in order to increase the light recycling effect between the substrate exit surface by the prism sheet and the reflective layer. If the reflective layer is conductive, it also functions as an auxiliary electrode.

In this manner, the light incident on the lower surface of the transparent substrate 20 is emitted to the outside with the light angle adjusted in two directions.
Furthermore, in the EL lighting device 50, the insulating film 51 and the reflective film 53 of the EL element 11, and the one-dimensional groove 52 and the prism portion 54 of the transparent substrate 20 are formed in stripes in one direction, respectively. Since the EL element 11 and the transparent substrate 20 need only be aligned in one direction, assembly can be easily performed.
Further, since the reflective film 53 is electrically connected to the transparent electrode 14, the reflective film 53 functions as an auxiliary electrode of the transparent electrode 14, thereby improving the electrical element efficiency of the EL element 11. it can.

As for the EL lighting device 50, as in the EL lighting device 10 shown in FIGS. 1 and 2, a simulation was performed when the apex angle θ of the prism portion 54 was changed from 80 to 150 degrees. As shown in FIG. 12, simulation results of the total luminous flux A and the on-axis luminance effect B were obtained.
In this case, since the insulating film 51 has a relatively low transmittance of about 30%, in order to improve the light recycling effect of the prism sheet 55, the EL film is compensated for the low transmittance of the insulating film 51. On the lower surface of the transparent electrode 14 of the element 11, a reflection film 53 made of metal as a partial reflection layer was inserted.
The reflective film 53 also acts as an auxiliary electrode when brought into contact with the transparent electrode 14, and the efficiency of the EL element 11 can be improved.

  According to the simulation result, the total luminous flux A slightly decreases to about 0.9 times, but when the apex angle θ of the prism portion 54 is 110 degrees, the on-axis luminance effect B is about 4.0 times the maximum. Become. Therefore, if the ratio of the light emission energy in the light emitting layer 12 to the internal light emission efficiency, that is, the power consumption in the EL element is the same as that of the conventional EL lighting device, the embodiment of the present invention is compared with the conventional EL lighting device. According to the EL illumination device 50, although the light extraction efficiency is slightly reduced to about 0.9 times the total luminous flux, it is possible to improve the on-axis luminance to 4.0 times. Thus, in order to obtain the same on-axis luminance, the power consumption is ¼ times.

FIG. 13 shows the emission surface luminance distribution at the apex angle 110 degrees of the prism portion 54 of the EL illumination device 50, and it can be seen that the luminance distribution is substantially uniform in the vertical direction and the horizontal direction.
Further, FIG. 14 shows far-field directivity characteristics at an apex angle of 110 degrees of the prism portion 54 of the EL illumination device 50. One direction in which the light angle is adjusted by the one-dimensional groove 52 of the transparent substrate 20 (light source orthogonal direction). ) And the direction perpendicular to the light angle adjusted by the prism sheet 55 (in the light source parallel direction), it can be seen that the far field directivity is different.
Therefore, by arranging the EL illumination device 50 so that the light source orthogonal direction coincides with the left-right direction of the liquid crystal display device and performing back illumination, the viewing angle is small in the left-right direction and the viewing angle is large in the up-down direction. A backlight can be configured, and is suitable as a backlight of a liquid crystal display of a portable personal information device, for example.

15 to 18 show the configuration of the fifth embodiment of the EL lighting device according to the present invention.
15, the EL illumination device 60 is different from the EL illumination device 50 shown in FIG. 10 in that the one-dimensional groove 52 in the transparent substrate 20 is omitted and the whole is made of the same refractive index material. It is configured.
In this case, the insulating film 51 is selected to have a pitch of 0.2 mm and a width of 0.15 mm, for example, and the transparent substrate 20 is selected to have a pitch of 0.2 mm, a width of 0.15 mm, and an apex angle of 60 to 120 degrees, for example. The prism sheet 55 is selected to have a thickness of 0.062 mm, an apex angle of 90 degrees, and a pitch of 0.024 mm, for example.

In the EL lighting device 60 having such a configuration, the light emitted from the light emitting layer 12 of the EL element 11 passes through the region of the light emitting portion 51 a defined by the insulating film 51 and is further defined by the reflective film 53. The light passes through the window portion and exits below the EL element 11 and enters the transparent substrate 20.
The light that enters the transparent substrate 20 from the EL element 11 enters the transparent substrate 20 in a region immediately below the light emitting portion 51a (hereinafter referred to as the light emitting portion region), and is then guided to the emission side to be transparent. The light is emitted from the emission side of the substrate 20 to the outside.

With respect to the transparent substrate 20, the light is emitted in a direction perpendicular to the downward direction in FIG. 1 at a relatively large incident angle in a direction perpendicular to the one direction.
On the other hand, the light incident on the transparent substrate 20 at a relatively large incident angle in the one direction also enters the non-light emitting portion region, that is, the prism portion 54 on the lower surface of the transparent substrate 20. Here, since the light incident on the prism portion 54 is incident on the inclined surface of the prism portion 54, the incident angle with respect to the prism portion 54 is reduced, and is not totally reflected by the inner surface of the prism portion 54. The light angle is adjusted and emitted to the outside.

  Further, the light incident on the transparent substrate 20 in the horizontal direction with respect to the one direction is emitted from the substrate without being converted by the first light angle conversion means, and is incident on the prism sheet 55. Of the light rays incident on the prism sheet, the light rays having a uniform angle condition are converted by the prism 55a and emitted to the outside, and the other light rays are reflected and returned to the EL element side. The reflected light beam is reflected again by the metal electrode or the reflective film, and so-called light recycling is performed by the prism sheet.

In this manner, the light incident on the lower surface of the transparent substrate 20 is emitted to the outside with the light angle adjusted in two directions.
Further, in the EL lighting device 60, the insulating film 51 and the reflective film 53 of the EL element 11 and the prism portion 54 of the transparent substrate 20 are formed in stripes in one direction. Since the alignment of the transparent substrate 20 is only required in one direction, the assembly can be easily performed.

Then, when the simulation of the EL lighting device 60 was performed, a simulation result of the on-axis luminance effect was obtained as shown in FIG.
That is, FIG. 16 shows the on-axis luminance effect when the apex angle θ of the prism portion 54 is changed from 60 to 120 degrees. Here, the on-axis luminance effect represents a multiple of the on-axis luminance when the same emission energy is applied as in the conventional EL lighting device using a flat transparent substrate on which the insulating film 51 is not formed.

According to this simulation result, when the apex angle θ of the prism portion 54 is 112 degrees, the on-axis luminance effect is about 3.40 times the maximum.
Therefore, if the ratio of the light emission energy in the light emitting layer 12 to the internal light emission efficiency, that is, the power consumption in the EL element is the same as that of the conventional EL lighting device, the embodiment of the present invention is compared with the conventional EL lighting device. According to the EL lighting device 60, it is possible to improve the on-axis luminance by a factor of 3.4. Thereby, in order to obtain the same on-axis luminance, power consumption of 1 / 3.4 is sufficient.

FIG. 17 shows the emission surface luminance distribution at the apex angle 112 degrees of the prism portion 54 of the EL illumination device 60. It can be seen that the luminance distribution is substantially uniform in the vertical direction and the horizontal direction.
Further, FIG. 18 shows far-field directivity characteristics at an apex angle of 112 degrees of the prism portion 54 of the EL illumination device 60, and one direction in which the light angle is adjusted by the prism portion 54 on the exit surface of the transparent substrate 20 ( It can be seen that the far-field directional characteristics are different between the light source orthogonal direction) and the direction perpendicular to the light angle adjusted by the prism sheet 55 (light source parallel direction).
Therefore, by arranging the EL illumination device 60 so that the light source orthogonal direction coincides with the left-right direction of the liquid crystal display device and performing back illumination, the viewing angle is small in the left-right direction and the viewing angle is large in the up-down direction. A backlight can be configured, and is suitable as a backlight of a liquid crystal display of a portable personal information device, for example.

19 to 21 show the configuration of the sixth embodiment of the EL lighting device according to the present invention.
In FIG. 19, the EL illumination device 70 differs from the EL illumination device 60 shown in FIG. 15 in that it includes a double-row prism portion 71 instead of the prism portion 54 in the transparent substrate 20. It is configured.
In this case, the insulating film 51 is selected to have a pitch of 0.4 mm and a width of 0.3 mm, for example, and the transparent substrate 20 is selected to have a pitch of 0.4 mm, a width of 0.3 mm, and an apex angle of 60 to 120 degrees, for example. The prism sheet 55 is selected to have a thickness of 0.062 mm, an apex angle of 90 degrees, and a pitch of 0.024 mm, for example.

In the EL lighting device 70 having such a configuration, the light emitted from the light emitting layer 12 of the EL element 11 passes through the region of the light emitting portion 51 a defined by the insulating film 51 and is further defined by the reflective film 53. The light passes through the window portion and exits below the EL element 11 and enters the transparent substrate 20.
The light that enters the transparent substrate 20 from the EL element 11 enters the transparent substrate 20 in a region immediately below the light emitting portion 51a (hereinafter referred to as the light emitting portion region), and is then guided to the emission side to be transparent. The light is emitted from the emission side of the substrate 20 to the outside.

The light that has entered the transparent substrate 20 at a relatively small angle enters the flat portion of the substrate emission surface at a small angle, and substantially exits in a substantially vertical axial direction downward in FIG.
On the other hand, light incident on the transparent substrate 20 at a relatively large incident angle in a direction perpendicular to the one direction also enters the non-light emitting portion region, that is, the prism portion 71 on the lower surface of the transparent substrate 20. Here, since the light incident on the prism portion 71 is incident on the double-row inclined surfaces of the prism portion 71, the incident angle with respect to the prism portion 71 becomes small and is totally reflected by the inner surface of the prism portion 71. Without being adjusted, the light angle is adjusted and emitted to the outside.

  Further, the light incident on the transparent substrate 20 in the horizontal direction with respect to the one direction is emitted from the substrate without being converted by the first light angle conversion means, and is incident on the prism sheet 55. Of the light rays incident on the prism sheet, the light rays having a uniform angle condition are converted by the prism 55a and emitted to the outside, and the other light rays are reflected and returned to the EL element side. The reflected light beam is reflected again by the metal electrode or the reflective film, and so-called light recycling is performed by the prism sheet.

In this manner, the light incident on the lower surface of the transparent substrate 20 is emitted to the outside with the light angle adjusted in two directions.
In this case, in the EL lighting device 70, the insulating film 51 and the reflective film 53 of the EL element 11 and the prism portion 71 of the transparent substrate 20 are each formed in a stripe shape in one direction. And the transparent substrate 20 need only be aligned in one direction. As a result, the assembly can be easily performed, and the prism portion 71 is double-rowed, so that the prism width per row is reduced by half. The height is also halved, and the overall thickness can be further reduced.
Therefore, even when the pitch of the light emitting units 12a and the pitch of the prisms are increased, the EL illumination device 70 can be configured to be thinner.

Then, when the simulation of the EL lighting device 70 was performed, a simulation result of the on-axis luminance effect was obtained as shown in FIG.
That is, FIG. 20 shows the on-axis luminance effect when the apex angle θ of the prism portion 71 is changed from 60 to 120 degrees. Here, the on-axis luminance effect represents a multiple of the on-axis luminance when the same emission energy is applied as in the conventional EL lighting device using a flat transparent substrate without the insulating film 51.

According to this simulation result, when the apex angle θ of the prism portion 71 is 90 degrees, the on-axis luminance effect is about 2.93 times the maximum.
Therefore, if the ratio of the light emission energy in the light emitting layer 12 to the internal light emission efficiency, that is, the power consumption in the EL element is the same as that of the conventional EL lighting device, the embodiment of the present invention is compared with the conventional EL lighting device. According to the EL illumination device 70, the on-axis luminance can be improved by 2.93 times. Thereby, in order to obtain the same on-axis luminance, the power consumption is 1 / 2.93 times.

FIG. 21 shows far-field directivity characteristics at an apex angle of 90 degrees of the prism portion 71 of the EL illumination device 70. One direction in which the light angle is adjusted by the prism portion 54 on the exit surface of the transparent substrate 20 ( It can be seen that the far-field directional characteristics are different between the light source orthogonal direction) and the direction perpendicular to the light angle adjusted by the prism sheet 55 (light source parallel direction).
Therefore, by arranging the EL illumination device 70 so that the light source orthogonal direction coincides with the left-right direction of the liquid crystal display device and performing back illumination, the viewing angle is small in the left-right direction and the viewing angle is large in the up-down direction. A backlight can be configured, and is suitable as a backlight of a liquid crystal display of a portable personal information device, for example.

22 to 25 show the configuration of the seventh embodiment of the EL lighting device according to the present invention.
In FIG. 22, the EL illumination device 80 has a concave shape with an apex angle θ of 90 to 170 degrees, for example, instead of the convex prism portion 54 in the transparent substrate 20, as compared with the EL illumination device 60 shown in FIG. 15. The configuration differs in that a prism section 81 having a triangular cross section is provided.

In the EL lighting device 80 having such a configuration, the light emitted from the light emitting layer 12 of the EL element 11 passes through the region of the light emitting portion 51 a defined by the insulating film 51 and is further defined by the reflective film 53. The light passes through the window portion and exits below the EL element 11 and enters the transparent substrate 20.
The light incident from the EL element 11 into the transparent substrate 20 enters the transparent substrate 20 in a region immediately below the light emitting unit 12a (hereinafter referred to as the light emitting unit region), and is then guided to the emission side to be transparent. The light is emitted from the emission side of the substrate 20 to the outside.

The light that has entered the transparent substrate 20 at a relatively small angle enters the flat portion of the substrate emission surface at a small angle, and substantially exits in a substantially vertical axial direction downward in FIG.
On the other hand, the light incident on the transparent substrate 20 with a relatively large incident angle in the one direction enters the non-light emitting portion region, that is, the prism portion 81 on the lower surface of the transparent substrate 20. Here, since the light incident on the prism portion 81 is incident on the inclined surface of the prism portion 81, the incident angle with respect to the prism portion 81 is reduced, and is not totally reflected by the inner surface of the prism portion 81. The light angle is adjusted and emitted to the outside.

  Further, the light incident on the transparent substrate 20 in the horizontal direction with respect to the one direction is emitted from the substrate without being converted by the first light angle conversion means, and is incident on the prism sheet 55. Of the light rays incident on the prism sheet 55, the light rays having a fixed angle condition are converted by the prism 55a and emitted to the outside, and the other light rays are reflected and returned to the EL element side. The reflected light beam is reflected again by the metal electrode or the reflective film, and so-called light recycling is performed by the prism sheet.

In this manner, the light incident on the lower surface of the transparent substrate 20 is emitted to the outside with the light angle adjusted in two directions.
In this case, in the EL lighting device 80, the insulating film 51 and the reflective film 53 of the EL element 11 and the prism portion 81 of the transparent substrate 20 are formed in stripes in one direction. And the transparent substrate 20 can be aligned in only one direction, so that the assembly can be easily performed, and the prism portion 81 is formed in a concave shape, so that the entire transparent substrate 20 can be further thinned. become.
Therefore, even when the pitch of the light emitting portions 51a and the pitch of the prisms are increased, the EL illumination device 80 can be configured to be thinner.

Then, when the simulation of the EL lighting device 80 was performed, as shown in FIG. 23, simulation results of the total luminous flux and the on-axis luminance effect were obtained.
That is, FIG. 23 shows the total luminous flux A and the on-axis luminance effect B when the apex angle θ of the prism portion 81 is changed from 90 to 170 degrees. Here, the on-axis luminance effect represents a multiple of the on-axis luminance when the same emission energy is applied as in the conventional EL lighting device using a flat transparent substrate without the insulating film 51.

According to this simulation result, although the total luminous flux A is about 0.9 times, when the apex angle θ of the prism portion 71 is 140 degrees, the on-axis luminance effect is about 3.2 times the maximum.
Therefore, if the ratio of the light emission energy in the light emitting layer 12 to the internal light emission efficiency, that is, the power consumption in the EL element is the same as that of the conventional EL lighting device, the embodiment of the present invention is compared with the conventional EL lighting device. According to the EL lighting device 80, the on-axis luminance can be improved by 3.2 times. Thus, in order to obtain the same on-axis luminance, power consumption of 1 / 3.2 times is sufficient.

FIG. 24 shows the emission surface luminance distribution at the apex angle 140 degrees of the prism portion 81 of the EL illumination device 80, and it can be seen that the luminance distribution is substantially uniform in the vertical and horizontal directions.
Further, FIG. 25 shows far-field directivity characteristics at an apex angle of 140 degrees of the prism portion 81 of the EL illumination device 80, and one direction in which the light angle is adjusted by the prism portion 54 on the exit surface of the transparent substrate 20 ( It can be seen that the far-field directional characteristics are different between the light source orthogonal direction) and the direction perpendicular to the light angle adjusted by the prism sheet 55 (light source parallel direction).
Therefore, by arranging the EL illumination device 80 so that the light source orthogonal direction coincides with the left-right direction of the liquid crystal display device and performing back illumination, the viewing angle is small in the left-right direction and the viewing angle is large in the up-down direction. A backlight can be configured, and is suitable as a backlight of a liquid crystal display of a portable personal information device, for example.

  In the embodiment described above, the entire transparent substrate 20 is made of a high refractive index material having a refractive index of 1.6, and the transparent material 25 filled in the two-dimensional groove or the one-dimensional groove is a low refractive index having a refractive index of 1.5. However, the present invention is not limited to this, and the transparent material 25 only needs to be made of a material having a refractive index lower than that of the material constituting the entire transparent substrate 20. It is not limited to .5.

In addition, numerical values such as the pitch and width of the light emitting portions 12a of the EL element 11 and the pitch and width of the two-dimensional groove or one-dimensional groove of the transparent substrate 20 are not limited to the illustrated dimensions, and may be other dimensions. It may be selected.
Furthermore, in the above-described embodiment, the prism sheet 55 is provided. However, the invention is not limited to this, and the prism sheet 55 may be omitted.

It is sectional drawing which shows 1st embodiment of EL lighting apparatus by this invention. It is a top view which shows the EL illumination apparatus of FIG. It is a graph which shows the total luminous flux and the axial luminance effect with respect to the prism apex angle by simulation in the EL illumination device of FIG. It is sectional drawing which shows 2nd embodiment of EL lighting apparatus by this invention. It is a top view which shows the EL illumination apparatus of FIG. 5 is a graph showing the total luminous flux and the on-axis luminance effect with respect to the prism apex angle by simulation in the EL illumination device of FIG. 4. It is sectional drawing which shows 3rd embodiment of EL lighting apparatus by this invention. It is a top view which shows the EL illumination apparatus of FIG. It is a graph which shows the total luminous flux and the on-axis brightness | luminance effect with respect to the prism vertex angle by simulation in the EL illumination device of FIG. It is sectional drawing which shows 4th embodiment of EL lighting apparatus by this invention. It is a top view which shows the EL illumination apparatus of FIG. It is a graph which shows the total luminous flux and the on-axis brightness | luminance effect with respect to the prism apex angle by simulation in the EL illumination device of FIG. It is a graph which shows the output surface luminance distribution by simulation in the EL illumination device of FIG. It is a graph which shows the directional characteristic by simulation in the EL illumination device of FIG. It is sectional drawing which shows 5th embodiment of EL lighting apparatus by this invention. FIG. 16 is a graph showing an on-axis luminance effect with respect to a prism apex angle obtained by simulation in the EL illumination device of FIG. 15. It is a graph which shows the output surface luminance distribution by simulation in the EL illumination device of FIG. It is a graph which shows the directional characteristic by simulation in the EL illumination device of FIG. It is sectional drawing which shows 6th embodiment of EL lighting apparatus by this invention. FIG. 20 is a graph showing an on-axis luminance effect with respect to a prism apex angle obtained by simulation in the EL illumination device of FIG. 19. FIG. It is a graph which shows the directional characteristic by simulation in the EL illumination device of FIG. It is sectional drawing which shows 7th embodiment of EL lighting apparatus by this invention. It is a graph which shows the total luminous flux and the on-axis brightness | luminance effect with respect to the prism apex angle by simulation in the EL illumination device of FIG. It is a graph which shows the output surface luminance distribution by simulation in the EL illumination device of FIG. It is a graph which shows the directional characteristic by simulation in the EL illumination device of FIG. It is sectional drawing which shows the structure of an example of the conventional EL illumination apparatus. It is sectional drawing which shows the structure of the other example of the conventional EL lighting apparatus. It is sectional drawing which shows the structure of the other example of the conventional EL lighting apparatus.

Explanation of symbols

10, 30, 40, 50, 60, 70, 80 EL illumination device 11 EL element 12 light emitting layer 12a light emitting part 13 metal electrode 14 transparent electrode 15 insulating film 20 transparent substrate 21 surface on incident side 22 two-dimensional groove (secondary Light angle conversion means)
23 exit surface 24 prism portion (first light angle conversion means)
25 Transparent material (second light angle conversion means)
31 Prism unit (first light angle conversion means)
41 frustoconical horn (first light angle conversion means)
42 Cylindrical part (second light angle conversion means)
43 Insulating film 51 Insulating film 51a Light emitting part 52 One-dimensional groove (second light angle conversion means)
53 Reflective film 54 Prism unit (first light angle conversion means)
55 Prism sheet 55a Prism 71 Double-row prism section (first light angle conversion means)
81 Prism part

Claims (7)

An EL lighting device comprising a flat transparent substrate and an EL element arranged so that the light emission side faces one surface of the transparent substrate,
The EL element is divided into a light emitting portion and a non-light emitting portion at a predetermined pitch in one direction on the light emitting surface,
The transparent substrate is, on the exit surface opposite to the above EL device, light emission from the first light angle converting means by the prism made of a non-emitting portion corresponds to a region convex or concave triangular cross section of the EL element It has a flat portion in the portion corresponding to the part area, further than the refractive index of the transparent substrate that is filled in a groove provided in correspondence with the non-light emitting region of the EL element at the incident surface characterized in that it comprises a second optical angle converter constructed by a transparent material composed of a low refractive index material of lower refractive index, EL lighting device.   2. The EL lighting device according to claim 1, wherein the EL element is divided into a light emitting portion and a non-light emitting portion at a predetermined pitch in a direction perpendicular to the one direction.   The EL illumination device according to claim 1, wherein the prism is formed in a double row.   2. The EL illumination device according to claim 1, wherein the groove is a one-dimensional groove provided on an incident surface side of the transparent substrate corresponding to a non-light emitting portion region of the EL element.   The EL illumination device according to claim 2, wherein the groove is a two-dimensional groove provided on the incident surface side of the transparent substrate corresponding to the non-light-emitting portion region of the EL element. An EL lighting device comprising a flat transparent substrate and an EL element arranged so that the light emission side faces one surface of the transparent substrate,
The EL element is divided into a light emitting portion and a non-light emitting portion at a predetermined pitch in two directions perpendicular to the light emitting surface,
The transparent substrate includes a first prism formed of a convex or concave frustoconical horn having a circular bottom surface centered on the center of the light emitting portion of the EL element on an emission surface opposite to the EL element. The light angle conversion means and the light emitting part region have a flat part corresponding to the light emitting part region, and correspond to the cylindrical part and the non-light emitting part region provided on the incident surface corresponding to the light emitting part region of the EL element. and a groove provided in the second light angle converting means constituted by a transparent material composed of a low refractive index material of refractive index lower than the refractive index of the transparent substrate that is filled in the trench An EL lighting device comprising: The groove is a two-dimensional groove provided on the incident surface side of the transparent substrate corresponding to the non-light emitting region of the EL element, and is cut so as to leave the cylindrical portion corresponding to the light emitting region of the EL element. The EL lighting device according to claim 6, wherein the EL lighting device is formed by being omitted.

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