Patent Publication Number: US-2019198719-A1

Title: Light emitting device, light source device, and display device

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims priority to Japanese Patent Application No. 2017-245041 filed on Dec. 21, 2017. The entire disclosure of Japanese Patent Application No. 2017-245041 is hereby incorporated herein by reference. 
     TECHNICAL FIELD 
     The present disclosure relates to a light emitting device, a light source device, and a display device. 
     BACKGROUND ART 
     In Japanese Unexamined Patent Publication No. 2011-140664, a light source device comprising a blue light emitting device, a green light emitting device, and a red light emitting device is described. A liquid crystal display device or the like using such a light source device can exhibit a high color reproducibility. 
     SUMMARY 
     Liquid crystal display devices and the like are sometimes required to have desired color reproductivity and light output according to use. Accordingly, various light emitting devices used for light source devices for liquid crystal display devices are also required to have such a color reproductivity and a light output. 
     In view of the above, one object of certain embodiments of the present invention is to provide a light emitting device or the like with which a liquid crystal display can have desired color reproducibility and light output. 
     A light emitting device according to certain embodiments of the present invention includes a first light emitting element and a first sealing member. The first light emitting element has a peak emission wavelength of 430 nm or greater and less than 490 nm. The first sealing member covers the first light emitting element, and contains a first phosphor having a peak emission wavelength of 490 nm or greater and 570 nm or less. A content of the first phosphor is 50 weight % or greater with respect to the total weight of the first sealing member. A mixed color light in which light emitted from the first light emitting element and light emitted from the first phosphor are mixed has an excitation purity of 70% or greater on a 1931 CIE chromaticity diagram. 
     According to certain embodiments of the present invention, it is possible to provide a light emitting device with which a liquid crystal display or the like having a desired color reproducibility or light output can be provided. 
    
    
     
       DESCRIPTION OF THE DRAWINGS 
         FIG. 1A  is a schematic top view of a light emitting device according to an embodiment. 
         FIG. 1B  is a schematic cross-sectional view of a line  1 B- 1 B in  FIG. 1A . 
         FIG. 2  is a drawing showing the light emission spectrum of the light emitting device. 
         FIG. 3  is a drawing showing the chromaticity of the light emitting device on the 1931 CIE chromaticity diagram. 
         FIG. 4A  is a schematic top view of the light emitting device according to an embodiment. 
         FIG. 4B  is a schematic cross-sectional view taken along line  4 B- 4 B in  FIG. 4A . 
         FIG. 5A  is a schematic top view of the light emitting device according to an embodiment. 
         FIG. 5B  is a schematic cross-sectional view of line  5 B- 5 B in  FIG. 5A . 
         FIG. 6  is a drawing showing the light emission spectrum of the light emitting device. 
         FIG. 7  is a schematic exploded perspective view of the display device of an embodiment. 
         FIG. 8A  is a schematic top view showing a lead part. 
         FIG. 8B  is a schematic top view of a package. 
         FIG. 8C  is a schematic top view of the light emitting device. 
         FIG. 9A  is a schematic top view showing an example of the light emitting device. 
         FIG. 9B  is a schematic cross sectional view taken along a line  9 B- 9 B in  FIG. 9A . 
     
    
    
     DETAILED DESCRIPTION OF EMBODIMENTS 
     A detailed explanation is given below based on the drawings. Parts with the same reference numeral represented in a plurality of drawings show parts or members that are the same or similar. 
     Furthermore, the description below is an example of the light emitting device to give a concrete form to the technical concept of the present invention, and the present invention is not limited to the description below. Unless specifically noted, descriptions on dimensions, materials, shapes and relative arrangements, etc., of components are not intended to limit the scope of the present invention thereto, but are given for exemplification. Also, in the description below, expressions that indicate a specific direction or position (e.g. “up,” “down,” and other terms that include those terms) may be used. Those expressions are used for ease of understanding of relative direction or position in the referenced drawings. The size or positional relationship, etc., of members shown by each drawing may be exaggerated to facilitate understanding, etc. The relationship of color names and chromaticity coordinates, the relationship of the light wavelength range and the color name of a monochromatic light, etc., are in compliance with JIS Z8110. 
       FIG. 1A  is a schematic top view of a light emitting device  100  according to one embodiment, and  FIG. 1B  is a schematic bottom view of the light emitting device  100 . In  FIG. 1A , illustrations of a first phosphor  7   a  and a first sealing member  40   a  are omitted. The light emitting device  100  comprises a first light emitting element  10   a  having a peak emission wavelength of 430 nm or greater and less than 490 nm, and a first sealing member  40   a  that covers the first light emitting element  10   a  and that contains the first phosphor  7   a  having a peak emission wavelength of 490 nm or greater and 570 nm or less. The light emitting device  100  shown in  FIG. 1A  further comprises a package  1  that comprises a recess  2 . 
     The light emitting device  100  comprises the first light emitting element  10   a  having the peak emission wavelength of 430 nm or greater and less than 490 nm. The first light emitting element  10   a  emits blue light. With the first light emitting element  10   a  having a peak emission wavelength of a longer wavelength than the near ultraviolet region, it is possible to reduce disadvantages of light in the near ultraviolet region (e.g. having an adverse effect on a human body or an irradiated object, causing degradation of the constituent members of the light emitting device, and a great decrease in the light emitting efficiency of the light emitting device). 
     The light emitting device  100  shown in  FIG. 1A  includes a single first light emitting element  10   a  disposed on the bottom surface of the recess  2 . The first light emitting element  10   a  has a rectangular outline shape in the top view. In the light emitting device  100 , it is possible to change the number of or the shape of the outline of the first light emitting elements  10   a  according to the purpose or application. 
     The first light emitting element  10   a  preferably has a height sufficiently smaller than the depth of the recess  2 . For example, the height of the first light emitting element  10   a  is 0.5 times or less than a depth of the recess  2 , preferably 0.4 times or less, and more preferably 0.37 times or less. The height of the first light emitting element  10   a,  for example, is 250 μm or less, and preferably 150 μm. Also, the depth of the recess  2  is preferably ⅔ or greater of the height of the package  1 . With this arrangement, inside the recess  2 , it is possible to increase the volume of the first sealing member  40   a  containing the phosphor  7   a  (green phosphor described later) placed in the recess  2 , and thus is possible to increase the content of the first phosphor  7   a . Thus, light emitted by the light emitting device  100  can have an excitation purity for the green light described below. 
     The light emitting device  100  comprises the first sealing member  40   a  that contains the first phosphor  7   a  having the peak emission wavelength in the range of 490 nm to 570 nm. The first sealing member  40   a  covers the first light emitting element  10   a . In the light emitting device  100  shown in  FIG. 1B , the first sealing member  40   a  includes a resin material such as silicone resin and the first phosphor  7   a  contained in the resin material. The first sealing member  40   a  is, for example, formed by hung placed inside the recess  2  using a potting technique, etc., and being solidified. 
     The first phosphor  7   a  is a green phosphor adapted to absorb blue light emitted by the first light emitting element  10   a,  and to emit green light. For the first phosphor  7   a,  it is preferable to use a (Ca, Sr, Ba) 8 MgSi 4 O 16  (F, Cl, Br) 2 :Eu phosphor, and particularly preferable to use a Ca 8 MgSi 4 O 16 Cl 2 :Eu phosphor. The Ca 8 MgSi 4 O 16 Cl 2 :Eu phosphor has high absorption efficiency with respect to light emitted from the first light emitting element  10   a,  and thus allows for easily reducing the blue component and increasing the green component in light emitted from the light emitting device  100 . Also, the Ca 8 MgSi 4 O 16 Cl 2 :Eu phosphor has a half band width in the light emission spectrum of 65 nm or less, with which the color reproducibility of a display device can be improved when the light emitting device  100  is incorporated in the display device as the light source. 
     The content of the first phosphor  7   a  in the first sealing member  40   a  is 50 weight % or greater with respect to the total weight of the first sealing member  40   a.  With the first phosphor  7   a  contained at 50 weight % or greater in the first sealing member  40   a,  it is possible to increase the ratio of the green component to the blue component in the light emission spectrum of the light emitting device  100 .  FIG. 2  is a drawing showing the light emission spectrum of the light emitting device  100 . The first light emitting element  10   a  and the first phosphor  7   a  are configured to have desired peak emission wavelengths such that, in the light emission spectrum of the light emitting device  100  shown in  FIG. 2 , the emission intensity at the peak emission wavelength of the first light emitting element  10   a  is 0.1 times or less of the emission intensity at the peak emission wavelength of the first phosphor  7   a.  More preferably, the first light emitting element  10   a  and the first phosphor  7   a,  are configured so that, in the light emission spectrum of the light emitting device  100  shown in  FIG. 2 , the peak emission intensity of the first light emitting element  10   a  is 0.01 times or more and 0.03 times or less of the peak emission intensity of the first phosphor  7   a.  With this arrangement, the light emitting device  100  can be a green-light emitting device in which the first light emitting element  10   a  configured to emit blue light serves as a light source. 
     Typically, in the case of a nitride-based light emitting element in which the light emitting layer contains indium, an amount of indium added in a green light emitting element is greater than that in a blue light emitting element, so that the light output of the green light emitting element is lower than that of the blue light emitting element. However, in the light emitting device  100  of the present disclosure, the first light emitting element  10   a,  which is a blue light emitting element, and the first phosphor  7   a,  which has high excitation efficiency with respect to the emitted light of the first fight emitting element  10   a,  is used, which allows for realizing higher light output compared to the nitride-based green light emitting element. 
     Also, with the first sealing member  40   a  containing the first phosphor  7   a  at 50 weight % or greater, on the 1931 CIE chromaticity diagram, the excitation purity of the mixed color light of the light emitted from the first light emitting element  10   a  and the light emitted from the first phosphor  7   a  can be 70% or greater. As used herein, the “excitation purity” represents a saturation of an emission color. The excitation purity P is represented by formula (I) or formula (II) shown below, where, on the 1931 CIE chromaticity diagram, the coordinates of the white point (i.e., achromatic point) are represented by N (x n , y n ), the chromaticity coordinates of light emitted from the light emitting device  100  (i.e., mixed color light) are represented by C (x c , y c ), and the coordinates of the intersection point of a straight line extending from the coordinates N toward the coordinates C with the spectrum locus are D (x d , y d ). 
     
       
         
           
             
               
                 
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     With the excitation purity P to the green light being 70% or greater, a display device in which the light emitting device  100  serving as the light source is incorporated, the color reproducibility in the green region can be improved. The excitation purity P is, for example, preferably 75% or greater, and more preferably 78% or greater. 
     The content of the first phosphor  7   a  in the first sealing member  40   a  is, for example, preferably 75 weight % or less with respect to the total weight of the first sealing member  40   a,  and more preferably 60 weight % or less. With such a content, as shown in the light emission spectrum of the light emitting device  100  shown in  FIG. 2 , the light emitting device  100  can have a small spike in the blue region. Accordingly, a portion of blue light emitted from the first light emitting element  10   a  with high light intensity is emitted to outside, so that it is possible to improve light emission intensity of the light emitting device  100 . Thus, while increasing the excitation purity of the green light of the light emitting device  100 , it is possible to have a light emitting device with even higher light emission intensity. 
     In addition to the first phosphor  7   a,  the first sealing member  40   a  preferably further contains a diffusion member such as SiO 2  with a small grain shape. With this arrangement, when manufacturing a plurality of light emitting devices, it is possible to reduce manufacturing variation in chromaticity between the plurality of light emitting devices. For example, among a plurality of light emitting devices, when the first sealing member  40   a  is disposed using potting, in a light emitting device in which potting was performed the first of the plurality of light emitting devices, the first phosphor  7   a  contained in the first sealing member  40   a  may be precipitated more downward compared to the light emitting device in which the potting was performed the last of the plurality of light emitting devices. With this arrangement, the chromaticity of the light emitting device in which the potting was performed the first of the plurality of light emitting devices and the chromaticity of the light emitting device in which the potting vas performed at the last of the plurality of light emitting devices may be different from each other. Meanwhile, a diffusion member such as SiO 2  with a small grain shape, serves to reduce precipitation of the phosphor particles in the scaling member, so that it is possible to effectively reduce variation in chromaticity among a plurality of light emitting devices. The grain shape of the diffusion member is, for example, 100 nm or less, and preferably 55 nm or less. Unless otherwise noted, in this specification, a particle diameter of a diffusion member, a light scattering particle, or the like, refers to a value determined as a Fisher Number measured by using Fisher-SubSieve-Sizer (F.S.S.S.) that employs an air permeable method. 
     As shown in  FIG. 3 , the chromaticity of the light emitting device  100 , for example, on the  1931  CIE chromaticity diagram, is positioned in a region surrounded by a first point  41 , a second point  42 , a third point  43 , and a fourth point  44 . The x, y coordinates of the first point  41  are 0.236, 0.620; the x, y coordinates of the second point  42  are 0.272, 0.700; the y coordinates of the third point  43  are 0.292, 0.700; and the x, y coordinates of the fourth point  44 , are 0.256, 0.620. 
     Next, a light emitting device  200  configured to emit red light, and a light emitting device  300  configured to emit blue light will be described.  FIG. 4A  is a schematic top view of the light emitting device  200  according to another embodiment, and  FIG. 4B  is a schematic cross-sectional view taken along a line  4 B- 4 B in  FIG. 4A .  FIG. 5A  is a schematic top view of the light emitting device  300  according to even another embodiment, and  FIG. 5B  is a schematic cross-sectional view taken along a line  5 B- 5 B in  FIG. 5A . With  FIG. 4A  and  FIG. 5A , illustration of the phosphor, the sealing member, etc., are omitted. The light emitting device  200  comprises a second light emitting element  10   b  having the peak emission wavelength of 430 nm or greater and less than 490 nm, and a second sealing member  40   b  that covers the second light emitting element  10   b  and that contains a second phosphor  7   b  having the peak emission wavelength of 580 nm or greater and 680 nm or less. Also, the light emitting device  300  comprises a third light emitting element  10   c  having the peak emission wavelength of 430 nm or greater and less than 490 nm, and a third sealing member  40   c  that covers the third light emitting element  10   c  and that does not contain phosphor. 
     The light emitting device  200  and the light emitting device  300  shown in  FIG. 4A  and  FIG. 5A  comprise the package  1  having the recess  2  as in the light emitting device  100 . Also, the second light emitting element  10   b  and the third light emitting element  10   c , similarly to the first light emitting element  10   a,  are light emitting elements having the peak emission wavelength of 430 nm or greater and less than 490 nm, and that emit blue light. With the second light emitting element  10   b  and the third light emitting element  10   c  each having a peak emission wavelength longer than the near ultraviolet region, disadvantages of light of the near ultraviolet region (e.g. an adverse effect on a human body or on an irradiated object, degradation of the constituent members of the light emitting device that leads to great reduction in light emission efficiency of the light emitting device). 
     For the package  1  used in the light emitting device  200  and the light emitting device  300 , a package similar to the package  1  of the light emitting device  100  can be used. In other words, for example, it is possible to have a depth of the recess  2  of the package  1 , or a ratio between a depth of the recess  2  and a height of the light emitting element, etc. be the same as those in the light emitting device  100 . 
     The light emitting device  200  comprises the second sealing member  40   b  that contains the second phosphor  7   b  having the peak emission wavelength of 580 nm or greater and 680 nm or less. The second sealing member  40   b  covers the second light emitting element  10   b . With the light emitting device  200  shown in  FIG. 4B , the second sealing member  40   b  in which the second phosphor  7   b  is contained in a resin material such as silicone resin. The second sealing member  40   b  is formed for example, by being disposed inside the recess  2  using the potting method, etc., and being solidified. 
     The second phosphor  7   b  is a red phosphor that absorbs the blue light emitted by the second light emitting element  10   b,  and that emits red light. For the second phosphor  7   b,  it is preferable to use an (Sr, Ca)AlSiN 3 :Eu phosphor. The half band width of the (Sr, Ca) AlSiN 3 :Eu phosphor in the light emission spectrum is 125 nm or less, so that color reproducibility of a display device that incorporates the light emitting device  200  as the light source can be improved. Further, the (Sr, Ca) AlSiN 3 :Eu phosphor, for example, is a phosphor with less afterglow than a phosphor such as K 2 SiF 6 :Mn 4+ , etc., so that the possibility of occurrence of an after-image or the like in the display device may be reduced. 
     The content of the second phosphor  7   b  within the second sealing member  40   b  is 50 weight % or greater with respect to the total weight of the second sealing member  40   b . With the second phosphor  7   b  contained at 50 weight % or greater in the second sealing member  400 , it is possible to increase the ratio of the red component with respect to the blue component in the light emission spectrum of the light emitting device  200 .  FIG. 6  is a drawing showing the light emission spectrum of the light emitting device  200 . The second light emitting element  10   b  and the second phosphor  7   b  are configured to have desired peak emission wavelengths such that, in the light emission spectrum of the light emitting device  200  shown in  FIG. 6 , the emission intensity at the peak emission wavelength of the second light emitting element  10   b  is 0.01 times or less of the emission Intensity at the peak emission wavelength of the second phosphor  7   b.  With this arrangement, the light emitting device  200  can be a light emitting device configured to emit red light while employing, the second light emitting element  10   b,  which is configured to emit blue light, as the light source. 
     The light emitting device  200  has excitation purity for red light, for example, of 85% or greater, preferably 90% or greater, and more preferably 95% or greater. With such an excitation purity, a display device in which the light emitting device  200  are incorporated as the light source can exhibit the color reproducibility improved in the red region. 
     The light emitting device  300  comprises a third sealing member  40   c  that does not contain a phosphor. The third sealing member  40   c  covers the third light emitting element  10   c.  The third sealing member  40   c  in the light emitting device  300  shown in  FIG. 5B , is obtained by solidifying a resin material such as a silicone resin. The light emitting device  300  does not comprise phosphor, so that it is possible to obtain a light emitting device in which the third light emitting element  10   c,  which emits blue light, serves as the light source to emit blue light. In the light emitting device  300 , an excitation purity of blue light is, for example, 85% or greater, preferably 90% or greater, and more preferably 95% or greater. With such an excitation purity, a display device in which the light emitting device  300  is incorporated as the light source can exhibit color reproducibility improved in the blue region. 
     The excitation purity of light emitted from the light emitting device  100  for the green light can be lower than, for example, the excitation purity of light emitted from the light emitting device  200  for the red light and the excitation purity of light emitted from the light emitting device  300  for the blue light. 
     Next, a display device  1000  that uses the light emitting device  100 , the light emitting device  200 , and the tight emitting device  300  will be explained.  FIG. 7  is an exploded perspective view of the display device  1000  according to still another embodiment. The display device  1000  comprises: a light guiding plate  12 ; a light source device including at least one light emitting device  100  (first light emitting device  100 ), at least one light emitting device  200  (second light emitting device  200 ), and at least one light emitting device  300  (third light emitting device  300 ); and a light-transmissive substrate  13  disposed on the top surface of the light guiding plate  12 . 
     The light guiding plate  12  includes a lateral surface  14  including a light-incident portion, and the at least one light emitting device  100 , the at least one light emitting device  200 , and the at least one light emitting device  300  are disposed facing the lateral surface  14  of the light guiding plate  12 . In the display device  1000  shown in  FIG. 7 , the light emitting device  100  two light emitting devices  200 , and two light emitting device  300  are arranged in a straight line. The display device of this disclosure is not limited to this. The number, arrangement, etc., of the light emitting devices can be changed according to the purpose or application. 
     The display device  1000 , for example, is a so-called see through type display device, which can show, as well as the display image, the backside of the display device. The see-through type display device can realize a novel display that could not be realized with conventional display devices, and thus can have a good eye-catching effect. 
     In the display device  1000 , with respect to the total value of luminous flux of all the light emitting, devices, the maximum luminous flux value is, for example, 50% or greater, preferably 60% or greater, and more preferably 65% or greater. With such a luminous flux value, it is possible to obtain a display device with a high brightness. Also, in the display device  1000 , the light emitting device  100  including the first light emitting element  10   a  and, the first phosphor  7   a  with high excitation efficiency with respect to light emitted from the first light emitting element  10   a  are used, so that a display device having a higher brightness particularly in the green region compared to a display device that uses the green light emitting element as the light source can be obtained. While a light source comprising a plurality of green light emitting elements instead of the light emitting device  100  can be used for a display device with a higher brightness, in the light emitting device  100 , adjustment of the concentration of the first phosphor  7   a  allows for adjusting chromaticity, luminous flux, or excitation purity of light emitted from the light emitting device easier than in a light source comprising a plurality of green light emitting elements instead of the light emitting device  100 . Also, the greater the number of the green light emitting elements, the more complicated wirings at a substrate side, etc. may become, and thus designing of the display device may become difficult. 
     Also, the display device  1000  comprises the first light emitting device  100 , the second light emitting device  200 , and the third light emitting device  300  each of which including a similar blue light emitting element, which allows for facilitating, designing of the display device. Furthermore, driving the light emitting devices individually for each emission color allows the display device  1000  according to the present disclosure to easily reproduce a desired light. Accordingly, electrodes, wirings at a substrate side, and the like in each of the light emitting devices can be simplified compared to, for example, the display device including one or more light emitting devices each comprising elements for emitting red, green, and red (RGB) light as the light source of the display device. 
     Configurations of the display device according to one embodiment of the present invention can be preferably applied also to display devices other than the see-through type display device. 
     Member used in the light emitting device  100 , etc., and the display device  1000  according to certain embodiments of the present invention will be described below in detail. 
     Light Emitting Element 
     The first light emitting element  10   a,  the second light emitting element  10   b , and the third light emitting element  10   c  function as a light source of the light emitting device, For the light emitting elements, light emitting diode elements or the like can be used, an. a nitride semiconductor that can emit light in the visible range (In x Al y Ga 1-x-y N, 0≤x, 0≤y, x+y≤1) can be preferably used. 
     The first light emitting element  10   a,  the second light emitting element  10   b , and the third light emitting element  10   c  are light emitting elements that have the peak emission wavelength of 490 mn or greater and 570 or less, and are configured to emit blue light. For each light emitting element, a light emitting element having a half band width of 40 nm or less is preferably used, and alight emitting element having a half band width of 30 nm or less. With such light emitting elements, for example, if a blue component is present in light emission spectrum of the light emitting device  100  or the light emitting device  200 , an integrated value of the blue component can be reduced, and possible to increase the purity of green or red. Also, in the light emitting device  300 , a sharp emission peak of a blue light can be easily obtained. Thus, for example, when using the light emitting device  300  for the light source of the display device, it is possible to obtain a display device with good color reproducibility in the blue region. 
     Each of the light emitting device  100 , the light emitting device  200 , and the light emitting device  300  includes a single light emitting element having a substantially rectangular planar shape. The light emitting device of the present disclosure may alternatively have any other appropriate shape. In the light emitting device  100 , etc., the planar shape of the light emitting element, the number of the light emitting element(s), and the arrangement of the light emitting elements, etc., can be changed according to the purpose or application. 
     First Sealing Member, First Phosphor 
     The light emitting device  100  comprises the first sealing member  40   a  that contains the first phosphor  7   a  adapted to convert the wavelength of the light emitted from the first light emitting element  10   a.  The first phosphor  7   a  is a phosphor having a peak emission wavelength of 490 nm or greater and 570 nm or less. For the first sealing member  40   a,  for example, a resin material in which the first phosphor  7   a  is contained in a silicone resin or the like is used, and the first sealing member  40   a  is formed using printing, an electrophoretic deposition method, potting, a spray method, etc. Also, the first sealing member  40   a,  for example, is made of resin member, glass, ceramic, or the like in a sheet form or block form, and is formed by bonding a resin member, etc. using an adhesive agent, etc. 
     For the resin material to be a base material of the first sealing member  40   a,  a thermosetting resin, a thermoplastic resin, etc. can be used, and for example, a resin containing silicone resin, epoxy resin, acrylic resin, or a resin containing one or more of these can be used. Also, in the first sealing member  40   a,  in addition to the first phosphor  7   a,  light scattering particles such as of titanium oxide, silicon oxide, zirconium oxide, aluminum oxide, etc., may be disposed. The light scattering particles may have a crushed shape, a spherical shape, a hollow shape, a porous shape, or the like. 
     For the first phosphor  7   a,  for example, a phosphor such as (Ca, Sr, Ba) 8 MgSi 4 O 16  (F, Cl, Br) 2 :Eu Si 6−z Al z O z N 8−z :Eu (0&lt;z&lt;4.2), Ba 3 Si 6 O 12 N 2 :Eu, or the like may be used. In particular, (Ca, Sr, Ba) 8 MgSi 4 O 16  (F, Cl, Br) 2 :Eu phosphor can be preferably used. 
     The first sealing member  40   a  can comprise another phosphor in addition to the first phosphor  7   a.  Examples of such another phosphor include a phosphor such as (Ca, Sr, Ba) 5 (PO 4 ) 3 (Cl, Br):Eu, Si 6−z Al x O z N 8−z :Eu (0&lt;z&lt;4.2), (Sr, Ca Ba) 4 Al 14 O 25 :En, (Ca, Sr, Ba) 8 MgSi 4 O 16  (F, Cl, Br) 2 :Eu, (Y, Lu, Gd) 3 (Al, Ga) 5 O 12 :Ce, Ca 3 Sc 2 Si 3 O 12 :Ce, and CaSc 2 O 4 :Ce. 
     Second Sealing Member, Second Phosphor 
     In the second sealing member  40   b,  a resin material, light scattering particles, etc., similar to those used in the first sealing member  40   a  can be appropriately used. The second sealing member  40   b  contains the second phosphor  7   b  for converting the wavelength of light emitted from the second light emitting element  10   b.    
     For the second phosphor  7   b,  for example, a phosphor such as (Sr, Ca)AlSiN 3 :Eu, CaAlSiN 3 :Eu, K 2 SiF 6 :Mn 4+ , or 3.5 MgO.0.5 MgF 2 .GeO 2 :Mn 4+  can be used. In particular, (Sr, Ca)AlSiN 3 :Eu phosphor can be preferably used. 
     Third Sealing Member 
     In the third sealing member  40   c,  a resin material, light scattering particles, etc., similar to those used in the first sealing member  40   a  can be appropriately used. The third sealing member  40   c  does not contain a phosphor. 
     Package 
     The light emitting device can comprise the package  1 . The package  1  is a base on which the light emitting element is to be disposed. The package  1  has includes a base body and a plurality of leads (i.e., plurality of electrode parts). The package  1  can define the recess  2 . Examples of a material used for the base body of the package  1  include, a ceramic of an aluminum oxide aluminum nitride, etc., a resin (for example, silicone resin, silicone modified resin, epoxy resin, epoxy modified resin, unsaturated polyester resin, phenol resin, polycarbonate resin, acrylic resin, trimethyl pentene resin, polynorbornene resin, or a hybrid resin of one or more of these resins, etc.), pulp, glass, or a composite material of these. 
     The outline of the package  1  has, for example, a quadrangular shape of 3.0 mm×1.4 mm, 2.5 mm×2.5 mm, 3.0 mm×3.0 mm, 4.0 mm×4.0 mm, or 4.5 mm×4.5 mm in a top view. The shape of the outline of the package  1  in the top view, is not limited to be a quadrangle, but may alternatively be another shape such as a polygon, elliptical shape, etc. 
     As an example, of the package  1 , a package comprising a resin part  30  used in the light emitting device  100  in  FIG. 1A  etc., a first lead  51 , and a second lead  52  can be preferably used. Such a structure allows for obtaining an inexpensive light emitting device with high heat dissipation performance. In the light emitting device  100  shown in  FIG. 1A , etc., the first lead  51  and the second lead  52  do not extend outward of the resin part  30  at an outer lateral surface of the package  1 , but the light emitting device according to the present embodiment is not limited to this. In other words, at an outer lateral surface of the package  1 , the first lead  51  and the second lead  52  may extend outward of the resin part  30 . With this arrangement, heat generated from the light emitting element can be efficiently dissipated to an outside. 
     Resin Part 
     For a resin material to be a base material of the resin part  30 , a thermosetting resin, thermoplastic resin, or the like may be used. More specifically, it is possible to use an epoxy resin compound, a silicone resin compound, a modified epoxy resin compound such as a silicone modified epoxy resin, a modified silicone resin compound such as an epoxy modified silicone resin, a cured article of a modified silicone resin compound, an unsaturated polyester resin, a saturated polyester resin, a polyimide resin compound, a modified polyimide resin compound, etc., or a resin such as polyphthalamide (PPA), polycarbonate resin, polyphenylene sulfide (PPS), liquid, crystal polymer (LCP), ABS resin, phenol resin, acrylic resin, or PBT resin. In particular, for the resin material of the resin part  30 , a thermosetting resin of an epoxy resin composition or a silicone resin composition with good hut resistance and light resistance can be used. 
     The resin part  30  preferably contains a resin material to be the base material as described above, and a light reflective substance in the resin material. For the light reflective substance, a material that does not easily absorb light emitted from the light emitting element and has a refractive index greatly different from that of the resin material to be the base material. Examples of such a light reflective substance includes titanium oxide, zinc oxide, silicon oxide, zirconium oxide, aluminum oxide, aluminum nitride, etc. 
     First Lead, Second Lead 
     The first lead  51  and the second lead  52  are electrically conductive, and function as electrodes for supplying electricity to the light emitting element. For a base member of each of the first lead  51  and the second had  52 , for example, a metal such as copper, aluminum, gold, silver, iron, nickel, or alloys of these, phosphor bronze, or iron containing copper, can be used. These materials can be used in a single layer, or in a layered structure (a clad member, for example). In particular, for the base material, copper, which is inexpensive and having high heat dissipation, can be used. 
     The first lead  51  and the second lead  52  may include a metal layer on a surface of the base material. The metal layer, for example, can contain silver aluminum, nickel, palladium, rhodium, gold, cover, or alloys of these, etc. The metal layer can be disposed on all or some of the surfaces of the first lead  51  and the second lead  52 . Also, the metal layer on an upper surface of each of the first and the second leads, and the metal layer on the lower surface thereof may be made of different materials. For example, the metal layer on the upper surface of each of the first and the second leads can be a metal layer comprising a plurality of layers including nickel layer and silver layer, and the metal layer on the lower surface of each of the first and the second leads can be a metal layer that does not include a nickel metal layer. 
     When a metal layer containing silver is formed on an outermost surface of the first lead  51  and/or an outermost surface of the second lead  52 , a protective layer of silicon oxide, etc., on a surface of the metal layer containing silver. With this arrangement, discoloration of the metal layer containing silver due to the sulfur component, etc., in the atmosphere can be reduced. The protective layer can be formed by, for example, using a vacuum process such as sputtering, but it is also possible to use another known method. 
     The package  1  comprises at least two electrodes (for example, the first lead  51  and the second lead  52 ). The package  1  may comprise three or more electrodes; for example, the package  1  can comprise a third lead in addition to the first lead  51  and the second lead  52 . The third lead may function as a heat dissipation member, and may also function as an electrode, similarly to the first lead  51 , etc. 
     Each of the first lead  51 , the second lead  52 , and the third lead, and the like, (hereafter referred to as “a lead, part  5 ”) can have a groove in an upper surface or a lower surface thereof. With the lead part  5  having grooves, adhesion between the lead part  5  and the resin part  30  can be improved. 
       FIG. 8A  is a schematic top view of the lead part  5  when grooves are formed on the top surface of the lead pan  5 .  FIG. 8B  is a schematic top view showing an example of the package  1  using the lead part  5 .  FIG. 8C  is a schematic top view showing an example of a light emitting device  400 . Each of  FIG. 8A  and  FIG. 8B  shows the lead part  5  exposed on the bottom surface of the recess  2 , in which regions with cross hatching indicate portions of the lead part  5  that have a smaller thickness, the lead part  5  has a first groove  81  on the upper surface of the first lead  51 , and a second groove  82  on the upper surface of the second lead  52 . Further, the upper surface of the first lead  51  includes a first element placing region  101  and a second element placing region  102 , and a first wire connection region  201  and a second wire connection region  202 . The upper surface of the second lead  52  includes a third element placing region  103  and a third wire connection region  203 . Each of the first to third element placing regions  101  to  103  is a region on which a respective light emitting element, a protection element, or the like, is mounted, and each of the first to third wire connection regions  201  to  203  is a region to which one end portion of a wire extending from the light emitting element, the protection element, or the like are connected. 
     In the package  1  shown in  FIG. 8B , the resin part  30  enters the first groove  81  and ate second groove  82 . Accordingly, at the bottom surface off the recess  2 , only a portion of the region including the element placing region and the wire connection region are exposed from the resin part  30 . With this arrangement, even if oxygen, sulfur, etc., enters the recess  2  an area of the first lead  51  and the second lead  52  exposed to oxygen, sulfur, etc., can be reduced, and possibility of occurrence of a rapid decrease in the light reflectance of the package  1  can be reduced. Thus, the package  1  can efficiently extract light emitted from the light emitting element to outside over a long period. 
     The wire connection region on the first lead  51  or the second lead  52  can be continuous with corresponding element placing region on the same lead, in the top view. For example, in the package  1  shown in  FIG. 8B , in the top view, the second element placing region  102  and the second wire connection region  202  are continuous on the upper surface of the first lead  51 . Also, in the top view, the third element placing region  103  and the third wire connection region  203  are continuous on the upper surface of the second lead  52 . With this arrangement, or example, if oxygen, sulfur, etc., enters the recess  2 , the oxygen, sulfur, etc., concentrates mainly in the first to third wire connection regions  201  to  203 , and it is possible to reduce the possibility of occurrence of breakage of the wires connected to the wire connection region. 
     The light emitting device  400  comprises, for example, two light emitting elements  10  for which the peak emission wavelength is 430 nm or greater and less than 490 nm, and one protection element  15 . The light emitting device  400  is, for example, a white light emitting device that contains phosphor. For the phosphor, for example, Si 6−x Al z O z N 8−z :Eu (0&lt;z&lt;4.2) phosphor and K 2 SiF 6 :Mn 4+  phosphor may be used in combination. Each of these phosphors has a narrow half band width in the light emission spectrum, so that color reproducibility of the display device in which the light emitting device  400  is used as the light source can be improved. The light emitting device  400  can be a blue light emitting device that does not contain phosphor. 
     The light emitting device may not comprise the package  1 .  FIG. 9A  is a schematic top view showing an example of a light emitting device  500  that does not comprise the package  1 , and  FIG. 9B  is a schematic cross sectional view taken along a line  9 B- 9 B in  FIG. 9A . The light emitting device  500  comprises the light emitting element  10 , the sealing member  40  disposed on the upper surface of the light emitting element  10 , the light-transmissive layer  11  disposed on a lateral surface of the light emitting element  10 , and the resin part  30  covering the outer surfaces of the light-transmissive layer  11 . The sealing member  40  can contain the first phosphor  7   a,  for example. 
     The light-transmissive layer  11  covers at least lateral surfaces of the light emitting clement  10 , and guides light emitted from the lateral surfaces of the light emitting element  10  toward the upper surface of the light emitting device  500 . With the light-transmissive layer  11  disposed on the lateral surfaces of the light emitting element  10 , of a light that have reached a lateral surface of the light emitting element  10 , a ratio of a portion of the light reflected at the lateral surface and attenuated can be reduced. In the light emitting device  500  shown in  FIG. 9B , the light-transmissive layer covers the tipper surface of the light emitting element  10  in addition to the lateral surfaces thereof. For a resin material to be used for a base material of the light-transmissive layer  11 , a resin material as in examples of the resin material of the resin part  30  can be used, and in particular, a light-transmissive resin such as silicone resin, silicone modified resin, epoxy resin, or phenol resin can be preferably used. The light-transmissive layer  11  preferably has high light transmittance. In view of this, it is preferable that the light-transmissive layer  11  does not have a substance that reflects, absorbs, or scatters light. 
     The resin part  30  covers the outer surfaces of the light-transmissive layer  11  disposed on the lateral surfaces of the light emitting element  10 , and a portion of each of the lateral surfaces of the light emitting element  10 . A resin material for the resin part  30  can be preferably selected such that, for example, when difference between the thermal expansion coefficient of the light-transmissive layer  11  and the thermal expansion coefficient of the light emitting element  10  (hereinafter referred to as a “first thermal expansion coefficient difference ΔT30”) and difference between the thermal expansion coefficient of the resin part  30  and the thermal expansion coefficient of the light emitting element  10  (hereinafter referred to as a “second thermal expansion coefficient difference ΔT40”) are compared, ΔT40&lt;ΔT30 are satisfied. Using such a material allows for preventing detachment of the light-transmissive layer  11  from each light emitting element. 
     The configurations of each light emitting device can also be suitably applied to other light emitting devices.