Patent Publication Number: US-2021165146-A1

Title: Light-emitting device

Description:
TECHNICAL FIELD 
     The present invention relates to a light-emitting device. 
     BACKGROUND ART 
     In recent years, there has been progress in the development of light-emitting devices using an organic EL. Such a light-emitting device is used as an illumination device or a display device and has a configuration in which an organic layer is interposed between a first electrode and a second electrode. Generally, a transparent material is used for the first electrode, and a metal material is used for the second electrode. 
     One of the light-emitting devices using an organic EL is a technology described in Patent Document 1. In the technique of Patent Document 1, the second electrode is provided only in a portion of a pixel in order to cause a display device using an organic EL to have optical transparency (see-through property). In such a structure, since a region located between a plurality of second electrodes transmits light, the display device can have optical transparency. Meanwhile, in the technique disclosed in Patent Document 1, a light-transmitting insulating film is formed between the plurality of second electrodes in order to define a pixel. In Patent Document 1, an example of a material of this insulating film includes an inorganic material such as a silicon oxide, or a resin material such as an acrylic resin. 
     RELATED DOCUMENT 
     Patent Document 
     
         
         [Patent Document 1] Japanese Unexamined Patent Publication No. 2011-23336 
       
    
     SUMMARY OF THE INVENTION 
     Technical Problem 
     Depending on the application of a light-transmitting light-emitting device, the amount and color of light transmitted through the light-emitting device may be desired to be restricted. Even in such a case, it is often the case that the amount and color of light which is radiated from a light-emitting unit of the light-emitting device is not desired to be restricted. 
     An exemplary problem to be solved by the present invention is to restrict the amount and color of light which is transmitted through a light-emitting device having optical transparency and to prevent the amount and color of light which is radiated from a light-emitting unit from being restricted. 
     Solution to Problem 
     According to the invention of claim  1 , there is provided a light-emitting device including: a light-transmitting substrate; a plurality of light-emitting units, provided on a first surface of the substrate away from each other, each light-emitting unit including a light-transmitting first electrode, a light-reflective second electrode, and an organic layer located between the first electrode and the second electrode; a light-transmitting region which is located between the light-emitting units, and through which light is transmitted in a thickness direction; and an optical filter that overlaps the light-transmitting region, and does not overlap the plurality of light-emitting units or overlaps a surface of the plurality of light-emitting units on an opposite side to a light emission surface. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The above and other objects, features and advantages will be made clearer from certain preferred embodiment described below, and the following accompanying drawings. 
         FIG. 1  is a cross-sectional view illustrating a configuration of a light-emitting device according to an embodiment. 
         FIG. 2  is a plan view of the light-emitting device. 
         FIG. 3  is a cross-sectional view illustrating a configuration of a light-emitting device according to Modification Example 1. 
         FIG. 4  is a cross-sectional view illustrating a configuration of a light-emitting device according to Modification Example 2. 
         FIG. 5  is a cross-sectional view illustrating a configuration of a light-emitting device according to Modification Example 3. 
         FIG. 6  is a cross-sectional view illustrating a configuration of a light-emitting device according to Modification Example 4. 
         FIG. 7  is a cross-sectional view of a light-emitting device according to Modification Example 5. 
         FIG. 8  is a plan view of a light-transmitting member shown in  FIG. 7 . 
         FIG. 9  is a plan view of a light-transmitting member according to Modification Example 6. 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In all the drawings, like elements are referenced by like reference numerals and the descriptions thereof will not be repeated. 
     Embodiment 
       FIG. 1  is a cross-sectional view illustrating a configuration of a light-emitting device  10  according to an embodiment.  FIG. 2  is a plan view of the light-emitting device  10 .  FIG. 1  corresponds to a cross-section A-A of  FIG. 2 . The light-emitting device  10  according to the embodiment includes a light-transmitting substrate  100 , a plurality of light-emitting units  140 , a light-transmitting region (second region  104  and third region  106 ), and an optical filter  200 . The plurality of light-emitting units  140  are provided on a first surface  100   a  of the substrate  100  and are separated from each other. The light-emitting unit  140  includes a light-transmitting first electrode  110 , an organic layer  120 , and a light-reflective second electrode  130 . The organic layer  120  is located between the first electrode  110  and the second electrode  130 . The light-transmitting region is located between the light-emitting units  140  and transmits light in the thickness direction of the light-emitting device  10 . The optical filter  200  overlaps the light-transmitting region and does not overlap the plurality of light-emitting units  140 . Meanwhile, the optical filter  200  may overlap the end of the light-emitting unit  140 . However, as shown in a modification example described later, the optical filter  200  may cover the surface of the light-emitting unit  140  on the opposite side to a light emission surface. In other words, the optical filter  200  is not located on the light emission side of the light-emitting unit  140 . Hereinafter, a detailed description will be given. 
     The substrate  100  is, for example, a glass substrate or a resin substrate which has optical transparency. The substrate  100  may have flexibility. In a case where the substrate has flexibility, the thickness of the substrate  100  is, for example, equal to or greater than 10 μm and equal to or less than 1,000 μm. The substrate  100  is polygonal such as, for example, rectangular or circular. In a case where the substrate  100  is a resin substrate, the substrate  100  is formed using, for example, polyethylene naphthalate (PEN), polyether sulphone (PES), polyethylene terephthalate (PET), or polyimide. In addition, in a case where the substrate  100  is a resin substrate, it is preferable that an inorganic barrier film of SiNx, SiON or the like is formed on at least one surface (preferably, both surfaces) of the substrate  100  in order to prevent moisture from permeating the substrate  100 . Meanwhile, in a case where the substrate  100  is formed of a resin substrate, there are a method of directly forming the first electrode  110  and the organic layer  120 , described later, on the resin substrate, a method of forming the first electrode  110  and subsequent layers on a glass substrate, then peeling off the first electrode  110  and the glass substrate, and further disposing a peeled-off laminate on the resin substrate, and the like. 
     The light-emitting unit  140  is formed on one surface of the substrate  100 . The light-emitting unit  140  has a configuration in which the first electrode  110 , the organic layer  120  including a light-emitting layer, and the second electrode  130  are laminated in this order. In a case where the light-emitting device  10  is an illumination device, the plurality of light-emitting units  140  extend linearly (for example, in straight lines) . The plurality of light-emitting units  140  preferably extend in parallel with each other. On the other hand, in a case where the light-emitting device  10  is a display device, the plurality of light-emitting units  140  may be disposed to form a matrix or may be configured to form a segment or display a predetermined shape (to display, for example, an icon). The plurality of light-emitting units  140  are formed for each pixel. 
     The first electrode  110  is a transparent electrode having optical transparency. A material of the transparent electrode is a metal oxide formed of a material containing a metal, for example, an indium tin oxide (ITO), an indium zinc oxide (IZO), an indium tungsten zinc oxide 
     (IWZO), a zinc oxide (ZnO) or the like. The thickness of the first electrode  110  is, for example, equal to or greater than 10 nm and equal to or less than 500 nm. The first electrode  110  is formed by, for example, sputtering or vapor deposition. Meanwhile, the first electrode  110  may be a conductive organic material such as a carbon nanotube or PEDOT/PSS. In addition, the first electrode  110  may have a laminated structure in which a plurality of films are laminated. In the drawing, a plurality of linear first electrodes  110  are formed on the substrate  100  in parallel with each other. Therefore, the first electrode  110  is not located in the second region  104  and the third region  106 . 
     The organic layer  120  includes a light-emitting layer. The organic layer  120  has a configuration in which, for example, a hole injection layer, a light-emitting layer, and an electron injection layer are laminated in this order. A hole transport layer may be formed between the hole injection layer and the light-emitting layer. In addition, an electron transport layer may be formed between the light-emitting layer and the electron injection layer. The organic layer  120  may be formed by vapor deposition. In addition, at least one layer of the organic layer  120 , for example, a layer which is in contact with the first electrode  110  may be formed using a coating method such as ink jetting, printing, or spraying. Meanwhile, in this case, the remaining layers of the organic layer  120  are formed by vapor deposition. In addition, all the layers of the organic layer  120  may be formed using a coating method. Meanwhile, another light-emitting layer (for example, inorganic light-emitting layer) may be included instead of the organic layer  120 . In addition, the color of light emitted from the light-emitting layer (or the color of light which is radiated from the organic layer  120 ) may be different from or the same as the color of light emitted from a light-emitting layer of an adjacent light-emitting unit  140  (or the color of light which is radiated from the organic layer  120 ). 
     The second electrode  130  includes a metal layer constituted of a metal selected from a first group consisting of, for example, Al, Au, Ag, Pt, Mg, Sn, Zn, and In, or an alloy of metals selected from this first group. Therefore, the second electrode  130  has light shielding characteristics or light reflectivity. The thickness of the second electrode  130  is, for example, equal to or greater than 10 nm and equal to or less than 500 nm. The second electrode  130  is formed by, for example, sputtering or vapor deposition. In the example shown in the drawing, the light-emitting device  10  includes a plurality of linear second electrodes  130 . The second electrode  130  is provided for each first electrode  110  and is larger in width than the first electrode  110 . For this reason, the entirety of the first electrode  110  is overlapped and covered with the second electrode  130  in the width direction when seen from the direction perpendicular to the substrate  100 . With such a configuration, the extraction direction of light emitted from the light-emitting layer of the organic layer  120  can be adjusted. Specifically, the radiation of light to the first surface  100   a  side of the light-emitting device  10  can be suppressed. Alternatively, the first electrode  110  may be larger in width than the second electrode  130 , and the entirety of the second electrode  130  may be covered with the first electrode  110  in the width direction when seen from a direction perpendicular to the substrate  100 . In this case, the amount of light emitted in the direction of the side of the light-emitting device  10  having the second electrode  130  formed thereon is relatively large. 
     The edge of the first electrode  110  is covered with an insulating film  150 . The insulating film  150  is formed by adding a photosensitive material in a resin material such as, for example, polyimide, and surrounds a portion of the first electrode  110  which serves as the light-emitting unit  140 . In other words, the insulating film  150  defines the light-emitting unit  140 . The insulating film  150  has optical transparency. However, the light transmittance is not required to be high. In a case where the optical transparency of the insulating film  150  is high, the transmittance of the second region  104  described later becomes higher, and the transmittance of the light-emitting device  10  increases. On the other hand, by reducing the transmittance of the insulating film  150 , it is possible to absorb light emitted in the light-emitting unit  140  which is diffused to the insulating film  150  side. Therefore, the light emitted from the light-emitting unit  140  can be emitted without being diffused when seen from the extraction surface. The edge of the second electrode  130  in its width direction is located over the insulating film  150 . In other words, when seen from a direction perpendicular to a direction in which the light-emitting unit  140  extends, a portion of the insulating film  150  protrudes from the second electrode  130 . In addition, in the example shown in the drawing, the organic layer  120  is also formed on the upper portion and lateral side of the insulating film  150 . 
     When seen from the direction perpendicular to a direction in which the light-emitting unit  140  extends (that is,  FIG. 2 ), the light-emitting device  10  includes a first region  102 , the second region  104 , and the third region  106 . 
     The first region  102  is a region overlapping the second electrode  130 . That is, when seen from the direction perpendicular to the substrate  100 , the first region  102  is covered with the second electrode  130  and has a width the same as or different from that of the light-emitting unit  140 . In the example shown in the drawing, the width of the first region  102  is larger than that of the light-emitting unit  140 . The first region  102  is a region through which light is not transmitted from the front surface to the rear surface and from the rear surface to the front surface of the light-emitting device  10  or the substrate  100 . 
     A region located between the second electrodes  130  serves as a region (light-transmitting region) through which visible light is transmitted. This light-transmitting region is constituted by the second region  104  (first light-transmitting region) and the third region  106  (second light-transmitting region). The second region  104  is a region of the light-transmitting regions which includes the insulating film  150 . The third region  106  is a region of the light-transmitting regions which does not include the insulating film  150 . The light transmittance of the third region  106  is higher than the light transmittance of the second region  104 . 
     The width of the second region  104  is smaller than the width of the third region  106 . Therefore, the light-emitting device  10  has sufficient optical transparency. In addition, the width of the third region  106  may be larger or smaller than the width of the first region  102 . In a case where the width of the first region  102  is set to 1, the width of the second region  104  is, for example, equal to or greater than 0 (or greater than 0 or equal to or greater than 0.1) and equal to or less than 0.2, and the width of the third region  106  is, for example, equal to or greater than 0.3 and equal to or less than 2. In addition, the width of the first region  102  is, for example, equal to or greater than 50 μm and equal to or less than 500 μm, the width of the second region  104  is, for example, equal to or greater than 0 μm (or greater than 0 μm) and equal to or less than 100 μm, and the width of the third region  106  is, for example, equal to or greater than 15 μm and equal to or less than 1,000 μm. 
     Meanwhile, in the example shown in  FIG. 1 , at least a portion of the layers of the organic layer  120  is continuously formed in the first region  102 , the second region  104 , and the third region  106 . In other words, the organic layer  120  of the plurality of light-emitting units  140  is continuously formed. With such a configuration, it is not necessary to use a mask when a continuous layer of the organic layer  120  is formed, and thus the manufacturing cost of the organic layer  120  can be reduced. However, the organic layer  120  is not required be formed in the third region  106 . In addition, the organic layer  120  is not required be formed in the second region  104 . In this case, the transmittance of the second region  104  and the third region  106  becomes higher, and the transmittance of the light-emitting device  10  also becomes higher. 
     In addition, the light-emitting units  140  may be lattice-shaped. In this case, the third region  106  becomes a region of the substrate  100  which is surrounded by the second electrodes  130 . 
     The light-emitting device  10  further includes the optical filter  200 . The optical filter  200  overlaps at least a portion of the light-transmitting region of the light-emitting device  10 , preferably, the entirety thereof. The optical filter  200  is, for example, a light-shielding filter, and is a filter that shields a portion of visible light which is transmitted through the light-transmitting region. In a region of the light-transmitting region of the light-emitting device  10  which overlaps the optical filter  200 , the transmittance of the visible light is, for example, equal to or greater than 10% and equal to or less than 80%. In this manner, the light-transmitting region of the light-emitting device  10  has the same function as that of light-shielding glass such as smoked glass. The optical filter  200  is, for example, a light-transmitting layer or a sheet which is lightly colored in black. 
     However, the optical filter  200  may be a color filter. In this case, the optical filter  200  transmits less light having a desired wavelength region than light having other wavelength regions. 
     In the example shown in  FIG. 1 , the optical filter  200  is provided on a surface (second surface  100   b ) of the substrate  100  on the opposite side to the light-emitting unit  140 . The optical filter  200  covers the entirety of the third region  106 , the entirety of the second region  104 , and a portion of the first region  102 . In other words, the edge of the optical filter  200  overlaps a portion of the first region  102  except the light-emitting unit  140 , specifically, a region of the second electrode  130  which is located outside the light-emitting unit  140 . The width of a region in which the optical filter  200  and the second electrode  130  overlap each other, in other words, a distance w 1  between the edge of the optical filter  200  and the edge of the second electrode  130  is, for example, equal to or greater than 0 μm and equal to or less than 1,000 μm. With such a configuration, even in a case where variation occurs in the position of the optical filter  200  with respect to the light-transmitting region (third region  106  and second region  104 ), or the width of the optical filter  200 , it is possible to prevent a portion of the light-transmitting region which is not covered with the optical filter  200  from occurring. 
     Next, a method of manufacturing the light-emitting device  10  will be described. First, the first electrode  110  is formed on the substrate  100  by, for example, sputtering. Next, the first electrode  110  is formed in a predetermined pattern by, for example, photolithography. Next, the insulating film  150  is formed on the edge of the first electrode  110 . For example, in a case where the insulating film  150  is formed of a photosensitive resin, the insulating film  150  is formed in a predetermined pattern by undergoing exposure and development steps. Next, the organic layer  120  and the second electrode  130  are formed in this order. In a case where the organic layer  120  includes a layer which is formed by vapor deposition, this layer is formed in a predetermined pattern using, for example, a mask or the like. The second electrode  130  is also formed in a predetermined pattern using, for example, a mask or the like. Thereafter, the light-emitting unit  140  is sealed using a sealing member (not shown). 
     The optical filter  200  is provided on the second surface  100   b  of the substrate  100 . The optical filter  200  is formed by, for example, coating (for example, screen printing). At this time, a position at which the optical filter  200  is formed is determined on the basis of, for example, the positions of the insulating film  150  and the second electrode  130 . Meanwhile, the optical filter  200  may be formed in advance in a sheet shape. In this case, the optical filter  200  is attached to the second surface  100   b  of the substrate  100  using, for example, an adhesive layer (or pressure-sensitive adhesive layer). 
     Hereinbefore, according to the present embodiment, the optical filter  200  covers the light-transmitting region of the light-emitting device  10  but does not cover the light-emitting unit  140 . Therefore, it is possible to restrict the amount and color of light which is transmitted through the light-emitting device  10 . In addition, the amount and color of light which is radiated from the light-emitting device  10  are not restricted. 
     MODIFICATION EXAMPLE 1 
       FIG. 3  is a cross-sectional view illustrating a configuration of a light-emitting device  10  according to Modification Example 1 and corresponds to  FIG. 1  of the embodiment. The light-emitting device  10  according to the present modification example has the same configuration as that of the light-emitting device  10  according to the embodiment, except that the edge of the optical filter  200  overlaps a region of the light-emitting unit  140  which is close to the insulating film  150 . The width w 3  of a portion of the light-emitting unit  140  which is covered with the optical filter  200  is preferably equal to or less than 10% of the width of the light-emitting unit  140 . 
     In the present modification example, the optical filter  200  covers the light-transmitting region of the light-emitting device  10 , and thus it is also possible to restrict the amount and color of light which is transmitted through the light-emitting device  10 . In addition, since the optical filter  200  covers only a fraction of the light-emitting unit  140 , the amount and color of light which is radiated from the light-emitting device  10  is not substantially restricted. 
     MODIFICATION EXAMPLE 2 
       FIG. 4  is a cross-sectional view illustrating a configuration of a light-emitting device  10  according to Modification Example 2 and corresponds to  FIG. 1  of the embodiment. The light-emitting device  10  according to the present modification example has the same configuration as that of the light-emitting device  10  according to the embodiment, except that the edge of the optical filter  200  overlaps a region of the third region  106  (second light-transmitting region) which is close to the insulating film  150 . 
     In other words, the optical filter  200  covers a portion of the third region  106  which excludes the edge but does not cover the edge of the third region  106 , the second region  104 , and the first region  102  (including the light-emitting unit  140 ). However, a distance between the edge of the second region  104  and the edge of the optical filter  200 , in other words, a distance w 4  between the edge of the second electrode  130  and the edge of the optical filter  200  is preferably equal to or less than 10% of the length obtained by adding the second region  104  to the third region  106 . 
     In the present modification example, the optical filter  200  covers a large portion of the third region  106 , and thus it is also possible to restrict the amount and color of light which is transmitted through the light-emitting device  10 . In addition, since the optical filter  200  does not cover the light-emitting unit  140 , the amount and color of light which is radiated from the light-emitting device  10  are not restricted. 
     Meanwhile, the edge of the optical filter  200  may overlap the second region  104  (first light-transmitting region). 
     MODIFICATION EXAMPLE 3 
       FIG. 5  is a cross-sectional view illustrating a configuration of a light-emitting device  10  according to Modification Example 3 and corresponds to  FIG. 1  of the embodiment. The light-emitting device  10  according to the present modification example has the same configuration as that of the light-emitting device  10  according to the embodiment, except that a sheet member  210  is included therein. 
     The sheet member  210  is, for example, a transparent resin, and is installed onto the second surface  100   b  of the substrate  100  using an adhesive layer  212  (or pressure-sensitive adhesive layer). The optical filter  200  is formed at least in a region of the sheet member  210  which faces the third region  106 . However, the optical filter  200  is not formed in a region of the sheet member  210  which overlaps the light-emitting unit  140 . 
     Meanwhile, in the drawing, a relative position between the optical filter  200  and the first region  102 , the second region  104 , and the third region  106  is as shown in the embodiment. However, this relative position may be the same as that in  FIG. 2 , may be the same as that in  FIG. 3 , and may be the same as that in  FIG. 4 . 
     In addition, in the example shown in the drawing, the optical filter  200  is provided on a surface of the sheet member  210  on the opposite side to the substrate  100 . However, the optical filter  200  may be provided on a surface of the sheet member  210  which faces the substrate  100 . In addition, the optical filter  200  may be formed by coloring a portion of the sheet member  210 . 
     In the present modification example, as is the case with the embodiment, it is also possible to restrict the amount and color of light which is transmitted through the light-emitting device  10 . In addition, the amount and color of light which is radiated from the light-emitting device  10  are not restricted. Further, the optical filter  200  can be installed onto the substrate  100  by attaching the sheet member  210  onto the substrate  100 , and thus the optical filter  200  can be easily installed onto the substrate  100 . 
     In addition, in a case where the refractive index of the sheet member  210  is between the refractive index of air and the refractive index of the substrate  100 , it is possible to improve the light extraction efficiency of the light-emitting device  10 . 
     MODIFICATION EXAMPLE 4 
       FIG. 6  is a cross-sectional view illustrating a configuration of a light-emitting device  10  according to Modification Example 4. The light-emitting device  10  according to the present modification example has the same configuration as that of the light-emitting device  10  according to Modification Example 3, except that the optical filter  200  is provided on the first surface  100   a  side of the substrate  100 . 
     Specifically, the light-emitting device  10  includes a sealing member  180 . The sealing member  180  seals the light-emitting unit  140 . In the example shown in the drawing, the sealing member  180  is a sheet-shaped member (for example, a resin sheet coated with an inorganic material on both sides thereof) and is installed on the substrate  100  and the light-emitting unit  140  with an insulating layer  182  (adhesive layer) interposed therebetween. The optical filter  200  is provided on a surface of the sealing member  180  on the opposite side to the substrate  100 . Meanwhile, the sealing member  180  may have another structure (for example, so-called can encapsulation structure). 
     The optical filter  200  covers all of the first region  102 , the second region  104 , and the third region  106 . In other words, the optical filter  200  does not have an opening at a position overlapping the light-emitting unit  140 . 
     Meanwhile, as is the case with Modification Example 3, the optical filter  200  may be provided on the sheet member  210 . In this case, the sheet member  210  is attached to the sealing member  180  using the adhesive layer  212  shown in  FIG. 5 . The optical filter  200  may be provided on a surface of the sheet member  210  which faces the sealing member  180 , may be provided on a surface of the sheet member  210  on the opposite side to the sealing member  180 , and may be provided inside the sheet member  210 . 
     In the present modification example, as is the case with the embodiment, it is also possible to restrict the amount and color of light which is transmitted through the light-emitting device  10 . In addition, since the optical filter  200  is provided on a surface of the light-emitting device  10  on the opposite side to a light emission surface, the amount and color of light which is radiated from the light-emitting device  10  are not restricted. In addition, since a pattern is not required to be provided in the optical filter  200 , a relative position between the light-emitting unit  140  and the optical filter  200  is not required to be aligned when the optical filter  200  is installed on the substrate  100 . Therefore, the yield rate of the light-emitting device  10  is improved. 
     Meanwhile, in a case where the sealing member  180  has optical transparency, a function of the optical filter  200  may be given to the sealing member  180  by coloring the sealing member  180 . In this case, since the sealing member  180  also serves as the optical filter  200 , the cost of the light-emitting device  10  is reduced. 
     MODIFICATION EXAMPLE 5 
       FIG. 7  is a cross-sectional view of a light-emitting system including a light-emitting device  10  according to Modification Example 5 and a light-transmitting member  20 .  FIG. 8  is a plan view of the light-transmitting member  20  shown in  FIG. 7 . In the present example, the substrate  100  is installed on one surface of the light-transmitting member  20  (holding member). The light-transmitting member  20  is, for example, window glass. In a case where the light-transmitting member  20  is window glass of a building or a moving object (for example, an automobile, a train, or an airplane) , the light emission surface (second surface  100   b ) of the substrate  100  faces, for example, the light-transmitting member  20 . That is, light emitted by the light-emitting unit  140  is radiated to the outside of a building or a moving object through the light-transmitting member  20 . Meanwhile, in a case where the light-emitting unit  140  is provided on the outer surface of a building or a moving object, the light emission surface of the substrate  100  faces an opposite side to the light-transmitting member  20 . 
     The light-transmitting member  20  is provided with a pattern  22  for giving light shielding characteristics. The pattern  22  is formed by, for example, bonding a light shielding layer, mixing a material to lower transmittance with a material of the light-transmitting member  20 , mixing a material of light shielding characteristics with glass in a case where the light-transmitting member has a structure in which glass and glass are coupled, or forming a light-shielding material in an intermediate layer located between glass and glass. However, the pattern  22  is not provided in a region (substrate holding region  24 ) of the light-transmitting member  20  which overlaps the substrate  100 . 
     In the present example, a portion of the light-emitting device  10  except the light-transmitting member  20  has a configuration shown in the embodiment and any of Modification Examples 1 to 4. As a first example, the optical filter  200  is located between the substrate  100  and the light-transmitting member  20 , and in a region which does not overlap the plurality of light-emitting units  140 . In this case, the optical filter  200  does not overlap at least a large portion (preferably the entirety) of the light-emitting unit  140 . In addition, as a second example, the optical filter  200  overlaps a surface of the plurality of light-emitting units  140  on the opposite side to the light emission surface. In this case, the optical filter  200  may overlap the light-emitting unit  140 . 
     Since the optical filter  200  is provided, it is possible to restrict the amount and color of light which is transmitted through the light-emitting device  10 . On the other hand, the amount and color of light which is radiated from the light-emitting device  10  are not restricted by the optical filter  200 . In addition, it is possible to reduce a difference between the transmittance of the light-transmitting member  20  and the transmittance of the light-emitting device  10 . In other words, in a case where the light-emitting system is viewed, it is possible to reduce a difference in appearance between a portion provided with the light-emitting device  10  and the other portions. In addition, it is possible to reduce the manufacturing costs of the light-emitting device  10  and the light-emitting system by mass-producing portions other than the optical filter  200  of the light-emitting device  10  and selecting the optical filter  200  having a transmittance not different from the transmittance of the light-transmitting member  20 . 
     Here, the transmittance of the optical filter  200  is preferably higher than the transmittance of a region of the light-transmitting member  20  which is provided with the pattern  22 . The reason is as follows. 
     Since the first region  102  of the light-emitting device  10  is a region in which the light-reflective second electrode  130  is formed, the light transmittance of the first region  102  is substantially 0%. Here, the area (substantially equal to the area of the substrate holding region  24 ) of the light-emitting device  10  installed in the substrate holding region  24  of the light-transmitting member  20  is set to S, and the area of the first region  102  is set to A. As described above, since the width of the second electrode  130  is small, the second electrode  130  is hardly visibly recognizable to the human eye. However, since the area of a region of the substrate holding region  24  through which light is transmitted is “S-A”, the amount of light which is transmitted through the substrate holding region  24  becomes smaller. Therefore, the substrate holding region  24  becomes darker overall than in a case where the second electrode  130  is not present. Therefore, in a case where the transmittance of the optical filter  200  is the same as the transmittance of the pattern  22  of the light-transmitting member  20 , the apparent transmittance of visible light of the light-emitting device  10  (that is, substrate holding region  24 ) becomes lower by A/S than the transmittance (hereinafter, referred to as B) of a region of the light-transmitting member  20  which has the pattern  22 . Consequently, by adjusting the transmittance of the optical filter  200  in a direction of becoming higher than B by B×A/S, it is possible to make it hard to feel a difference between the apparent transmittance of the light-emitting device  10  and the substrate holding region  24  and that of the pattern  22 . 
     In a case where visible light is transmitted through the substrate holding region  24  of the light-transmitting member  20  and the light-emitting device  10  by performing the above adjustment, the light transmittance thereof is equal to or greater than 80% and equal to or less than 120% of the transmittance of visible light of a region of the light-transmitting member  20  which is provided with the pattern  22 , preferably equal to or greater than 90% and equal to or less than 110%, more preferably equal to or greater than 95% and equal to or less than 105%, and further more preferably equal to or greater than 99% and equal to or less than 101%. 
     Meanwhile, the transmittance of light of a region in which the substrate holding region  24  and the light-emitting device  10  overlap each other is defined and measured, for example, as follows. In the substrate holding region  24  of the light-transmitting member  20 , the area of a region overlapping the first region  102  is set to S1, the area of a region overlapping the second region  104  is set to S2, and the area of a region overlapping the third region  106  is set to S3. In addition, in the substrate holding region  24 , the transmittance of light of a region overlapping the first region  102  is set to X, the transmittance of light of a region overlapping the second region  104  is set to Y, and the transmittance of light of a region overlapping the third region  106  is set to Z. Then, the transmittance of light which is transmitted through the substrate holding region  24  and the light-emitting device  10  is regarded as 
       ( S 1× X+S 2× Y+S 3× Z )/( X+Y+Z )×100(%).
 
     In addition, the transmittance of light of a region in which the substrate holding region  24  and the light-emitting device  10  overlap each other may be measured using a method of measuring total light transmittance specified in JIS K 7375:2008. Further, in a case where the intensity of light incident on the entire surface of the light-emitting device  10  from the first surface  100   a  side of the substrate  100  is set to P, and the intensity of light emitted from the second surface  100   b  side of the substrate  100  is set to T, the transmittance of light of a region in which the substrate holding region  24  and the light-emitting device  10  overlap each other may be set to T/P×100%. 
     However, a method of measuring the transmittance of light of a region in which the substrate holding region  24  and the light-emitting device  10  overlap each other is not limited to these examples. 
     Meanwhile, the transmittance of visible light transmitted through the substrate holding region  24  of the light-transmitting member  20 , the optical filter  200 , and the light-emitting device  10  may be equal to or greater than 80% and equal to or less than 120% of the transmittance of visible light of the pattern  22  (peripheral region) of the light-transmitting member  20 . 
     With such a configuration, when the light-emitting device  10  does not emit light, a person viewing the light-transmitting member  20  is not likely to recognize a boundary between a region which is provided with the light-emitting device  10  and a region in the periphery thereof. In other words, a person viewing the light-transmitting member  20  is not likely to notice that the light-emitting device  10  is present. Meanwhile, the transmittance of visible light of a region of the light-transmitting member  20  which is not provided with the light-emitting device  10  can also be regarded as the transmittance of visible light in a region in which the light-transmitting member  20  and the pattern  22  overlap each other. 
     Here, in the area S (substantially the area of the substrate holding region  24 ) of the light-emitting device  10  installed in the substrate holding region  24  of the light-transmitting member  20 , the first region  102  of the light-emitting device is a region in which the light-reflective second electrode  130  is formed, and its light transmittance is substantially 0%. Here, in a case where an area occupied by the first region  102  in S is set to A, and the transmittance of the optical filter  200  is the same as the transmittance of the pattern  22  of the light-transmitting member  20 , the apparent transmittance in the light-emitting device  10  and the substrate holding region  24  becomes lower by A/S than the transmittance (hereinafter, referred to as B) of the pattern  22  portion. Consequently, the transmittance of the optical filter  200  is adjusted by B×A/S, and thus it is possible to make it hard to feel a difference in apparent transmittance between the light-emitting device  10  and the substrate holding region  24  and the pattern  22 . 
     MODIFICATION EXAMPLE 6 
       FIG. 9  is a plan view of a light-transmitting member  20  according to Modification Example 6. The present modification example has the same configuration as that of the light-emitting device  10  according to Modification Example 5, except for the following points. 
     In the present modification example, the light-emitting device  10  does not include the optical filter  200 . Instead thereof, the pattern  22  is also formed in the substrate holding region  24  of the light-transmitting member  20 , except for a region overlapping the light-emitting unit  140 . In other words, the pattern  22  is provided in at least a portion of the light-transmitting member  20  which overlaps the third region  106  but is not provided in a region of the light-transmitting member  20  which overlaps the light-emitting unit  140 . A region of the pattern  22  which overlaps the substrate  100  functions as an optical filter. 
     Meanwhile, a relative position between the pattern  22  in the substrate holding region  24  and the insulating film  150 , and the second electrode  130  is the same as the relative position between the optical filter  200  in the embodiment or any of Modification Examples 1 to 4 and the insulating film  150 , and the second electrode  130 . In addition, the light transmittance of a portion of the pattern  22  which is located in the substrate holding region  24  may be higher than the light transmittance of other portions of the pattern  22 . By appropriately setting a difference between these light transmittances, a difference between the light transmittance of visible light of a region of the light-transmitting member  20  which is not provided with the substrate  100  and the light transmittance of visible light of a region in which the light-transmitting member  20  and the substrate  100  overlap each other can be made smaller (for example, equal to or less than 10%, preferably equal to or less than 5%, more preferably equal to or less than 1%). 
     According to the present modification example, it is possible to restrict the amount and color of light which is transmitted through the light-emitting device  10 . In addition, the amount and color of light which are radiated from the light-emitting device  10  are not restricted. In addition, the optical filter  200  is not required to be installed on the substrate  100 . 
     As described above, although the embodiments and examples of the present invention have been set forthwith reference to the accompanying drawings, they are merely illustrative of the present invention, and various configurations other than those stated above can be adopted. 
     This application claims priority from Japanese Patent Application No. 2016-025293 filed on Feb. 12, 2016, the content of which is incorporated herein by reference in its entirety.