KR20070035591A - Light emitting device, backlight unit for lighting, display unit and display unit - Google Patents

Abstract

In order to increase the luminous efficiency and color rendering property, the light source 3 and at least one light emitting material that are excited by the light emitted by the light source 3 and emit light containing a component having a longer wavelength than the light emitted by the light source 3 may be used. It is excited by the light emitted from the first light emitting portion 4 and the light source 3 and the first light emitting portion 4 to contain and emits light containing a component having a longer wavelength than the light emitted from the first light emitting portion 4. In the light emitting device 1 having the second light emitting portion 5 containing at least one kind of light emitting material, at least part of the light emitted from the first light emitting portion 4 is directed to the second light emitting portion 5. The light shielding part 6 which prevents incidence is formed.

Light emitting device, partition plate, partition plate, color rendering, luminous efficiency

Description

Backlight Unit and Display Unit for Light Emitting Device, Lighting, Display Device {LIGHT EMITTING DEVICE, BACKLIGHT UNIT FOR LIGHTING, DISPLAY UNIT AND DISPLAY UNIT}

The present invention relates to a light emitting device, a backlight, a backlight unit for a display device, and a display device.

Conventionally, the cold cathode tube etc. were used as a light source, such as illumination and the backlight for liquid crystal displays. By the way, as a light source which replaces this, the pseudo white light source which combined the blue light source and the material which absorbs blue light and emits yellow light was developed. In this pseudo white light source, for example, an InGaN-based light emitting diode is used as a light source emitting blue light, and yttrium aluminate added with cerium is used as a material emitting yellow light.

However, the spectrum of the light emitted by the pseudo white light source essentially lacks the green light component and the red light component. For this reason, the pseudo white light source has low color rendering and low color reproducibility. To solve this problem, by adjusting the component of yttrium aluminate to emit yellow green light, and further adding a substance which absorbs blue light and emits red light to yttrium aluminate, the red component of the light emitted by the pseudo white light source is insufficient. It has been proposed to replenish the problem and to improve color rendering and color reproducibility.

However, the material emitting red light often absorbs not only blue light but also light having a longer wavelength than blue light but shorter wavelength than red light, that is, green or yellow light. For example, as such a substance, sulfides of alkaline earth metals activated by europium, nitrides of alkaline earth metals and silicon activated by europium, oxynitrides of alkaline earth metals and silicon activated by europium and the like can be given. These substances normally absorb light of a wavelength of 400 nm to 580 nm and emit light of red to red color having a peak at 580 nm to 680 nm.

The material that emits light of orange color to red represented above will absorb green to yellow light having a shorter wavelength than that. Therefore, if the material of light emission of green light to yellow light is mixed, The light emitting device absorbs a part of the light emitted by the green-yellow light, and the light-emitting device of the light emitting device is significantly reduced.

At present, attempts have been made to solve the degradation of the luminous flux due to absorption of short wavelength light by a light emitting material emitting long wavelength light. For example, Patent Literature 1 discloses a light emitting device having two kinds of materials (called materials A and B) that absorb light from a light source and emit light of different wavelengths, wherein material A (here, When a substance B (here, it corresponds to a substance emitting green to yellow light) absorbs a part of the light emitted from the material B (here, it corresponds to a substance emitting orange to red light), by placing the substance A closer to the light source side than the substance B It is said that the color rendering property can be improved and the fall of luminous flux can be prevented.

Moreover, conventionally, the display apparatus which irradiates light (backlight) from the back surface with respect to the image forming unit in which the certain image was formed, and displays the image of the image forming unit clearly has been used. Examples of such a display device include a liquid crystal display using a liquid crystal unit as an image forming unit, and an internal lighting sign (such as an emergency exit indicator or a road sign) in which a sign (image forming unit) is illuminated with internal lighting.

These display devices usually have a backlight unit for irradiating light from the back side to the image forming unit. As such a backlight unit, a fluorescent lamp, a cold cathode tube, etc. were used conventionally.

However, when a fluorescent lamp or a cold cathode tube is used as the backlight unit, in addition to the difficulty in miniaturizing the backlight unit, there have been problems such as short service life.

In addition, since they use mercury, they are concerned about the environmental impact, and the handling thereof may be complicated.

Therefore, as described above, it has recently been proposed to use a light emitting device using a light source and a fluorescent material which absorbs light from the light source and emits fluorescence as the backlight unit. For example, a technique has been proposed in which the above-described InGaN-based light emitting diode and a pseudo white light source using yttrium aluminate containing cerium as a light source and a light emitting material are used as a backlight unit.

In addition, for example, it is also proposed to use the light emitting device proposed in Patent Document 1 as a backlight.

Patent Document 1: Japanese Unexamined Patent Publication No. 2004-71726

Disclosure of the Invention

Problems to be Solved by the Invention

However, in the technique of Patent Literature 1, since the light emitted from the substance A or the substance B is emitted in all directions, most of the light emitted by the substance B (approximately half) is absorbed by the substance A, and a significant decrease in the luminous flux is avoided. Can't. For this reason, the luminous efficiency of the light emitting device was low.

Further, as described above, light emitting devices such as a light source emitting blue light and a pseudo white light source having a substance which absorbs blue light and emits yellow light emit high luminous efficiency but have insufficient color rendering.

In addition, in the display device using the conventional light-emitting device, in order to display the color of the image formed in the image forming unit with high reproducibility (that is, to improve the color reproducibility), the white light used for the backlight is a light including three primary colors of light. It is preferable. Here, the three primary colors of light mean red, blue, and green. According to this aspect, in the conventional light emitting device using a light source that emits blue light and a fluorescent material that emits yellow light, since red and green light are small, color reproducibility is not sufficient.

Moreover, when the technique of patent document 1 is used for a display apparatus, since white light containing all of blue, green, and red can be emitted, color reproducibility is no problem. However, as described above, light emitted from the fluorescent material (i.e., red and green light) is emitted in all directions, and most of the light emitted by the green fluorescent material is absorbed by the red fluorescent material, causing a significant decrease in the luminous flux. For this reason, the luminous efficiency of the backlight unit was lowered, and the energy consumed by the display device using the same was also easily increased.

SUMMARY OF THE INVENTION The present invention has been devised in view of the above problems, and improves the luminous efficiency and color rendering property of a light emitting device having two or more light emitting materials which absorb light and emit light, and an illumination using the light emitting device, and a backlight unit for a display device. And a display device, and a display device having excellent color reproducibility using a backlight unit having high luminous efficiency.

Means to solve the problem

The inventors of the present invention have made intensive studies to solve the above problems, and as a result, in a light emitting device using two or more kinds of light emitting materials, light emitted by one of the light emitting materials does not enter the region containing the other light emitting material. It has been found that the amount of light emitted from one of the light emitting materials is absorbed by the other light emitting material, and as a result, the light emission efficiency and the color rendering of the light emitting device can be improved.

In view of the above, in a display device using a backlight, a backlight unit that emits white light includes a blue light source that emits blue light, a green light emitting part that emits green light with a blue light source that is excited and emitted by blue light, and And a red light emitting part which has a red light emitting body which is excited by blue light and emits light, and emits red light. The green light emitting part and the red light emitting part are formed at least partially independently, thereby increasing the luminous efficiency of white light. The inventors have found that the color reproducibility of the display device can be improved, thereby completing the present invention.

That is, the light emitting device of the present invention comprises a first light emission containing a light source and at least one light emitting material that is excited by the light emitted by the light source and emits light containing a component having a longer wavelength than the light emitted by the light source. And a second light emitting portion containing at least one light emitting material that is excited by the light emitted from the light source and the first light emitting portion and can emit light containing a component having a longer wavelength than the light emitted by the first light emitting portion; And a light shielding portion for preventing at least a part of the light emitted from the first light emitting portion from being incident on the second light emitting portion (claim 1). This suppresses the light emitted from the first light emitting portion from being absorbed by the second light emitting portion, and as a result, both the luminous efficiency and the color rendering of the light emitting device can be improved.

At this time, it is preferable that this light shielding part reflects at least one part of the light emitted from this 1st light emitting part (claim 2). Thereby, the light emitted from a 1st light emitting part can be used effectively, and the luminous efficiency and color rendering property of a light emitting device can be improved more.

Moreover, the illumination of this invention was characterized by using the said light-emitting device (claim 3).

In addition, the backlight unit for a display device of the present invention is characterized by using the above light emitting device (claim 4).

Moreover, the display device of this invention used said light emitting device, It is characterized by the above-mentioned (claim 5).

Another display device of the present invention is a display device comprising a backlight unit for emitting a backlight and an image forming unit for irradiating the backlight emitted from the backlight unit to a back side and forming an image on the surface side, The backlight unit includes a first light emitting portion containing a light source and at least one light emitting material that is excited by the light emitted by the light source and can emit light containing a component having a longer wavelength than the light emitted by the light source, At least one type of light emission that is formed at least partially independently from the first light emitting portion and that is excited by the light source and the light emitted by the first light emitting portion and emits light containing a component having a longer wavelength than the light emitted by the first light emitting portion And a second light emitting portion containing the substance (claim 6). Thereby, both luminous efficiency and color reproducibility of a display device can be improved.

Another display device according to the present invention is a display device comprising a backlight unit for emitting white light and an image forming unit for irradiating the white light emitted by the backlight unit to a back side and forming an image on the surface side. The backlight unit has a blue light source that emits blue light, a green light emitter that is excited and emitted by the blue light, and is formed at least partially independently from the green light emitting part that emits green light, and by the blue light. It is characterized by having a red light-emitting body which is excited and emits light and which emits red light (claim 7). Thereby, both the luminous efficiency and color reproducibility of a display apparatus can be improved.

At this time, it is preferable that the display device includes a diffuser plate for diffusing light emitted from the backlight unit between the backlight unit and the image forming unit (claim 8).

Moreover, it is also preferable that the said display apparatus has a light guide plate which guides the light from this backlight unit to this image formation unit (claim 9).

Effects of the Invention

According to the present invention, a light emitting device excellent in both luminous efficiency and color rendering can be obtained.

In addition, when the light emitting device of the present invention is used, it is possible to obtain an illumination excellent in luminous efficiency and color rendering property, a backlight unit for a display device, and a display device.

Moreover, according to the display apparatus of this invention, both the luminous efficiency and color reproducibility of a display apparatus can be improved.

1A and 1B are diagrams schematically showing the main parts of a light emitting device as a first embodiment of the present invention, in which FIG. 1A is a sectional view thereof, and FIG. 1B is an exploded perspective view thereof.

2 (a) and 2 (b) are diagrams schematically showing the main parts of a light emitting device as a second embodiment of the present invention, in which Fig. 2 (a) is a sectional view thereof and Fig. 2 (b) is a perspective view thereof; to be.

3 is a diagram schematically illustrating a cross section of a main portion of a display for explaining an example of a backlight unit using the light emitting device of the present invention.

4 is a schematic exploded perspective view illustrating an outline of a display device as a third embodiment of the present invention.

5 is a schematic plan view of a backlight unit in a third embodiment of the present invention.

It is typical sectional drawing for demonstrating the principal part of the backlight unit in 3rd Embodiment of this invention.

7 is a chromaticity diagram for explaining a preferred range as a color coordinate of light in which blue light and green light are synthesized in the display device according to the third embodiment of the present invention.

It is typical sectional drawing for demonstrating the principal part of the backlight unit in the modified example of 3rd Embodiment of this invention.

9 is a cross-sectional view schematically showing an example of a configuration of a light emitting unit using a frame of a surface mount type of a backlight unit in a modification of the third embodiment of the present invention.

It is sectional drawing which shows typically the structure of the display apparatus using the light guide plate as a modification of 3rd Embodiment of this invention.

It is a chromaticity diagram for demonstrating the synthesis | combining method of white light in Examples 1-4 of this invention.

12 is a graph showing the light emission intensity distribution with respect to the wavelength of white light calculated in Example 1 of the present invention.

13 is a graph showing the light emission intensity distribution with respect to the wavelength of white light calculated in Example 2 of the present invention.

Fig. 14 is a graph showing the light emission intensity distribution with respect to the wavelength of white light calculated in Example 3 of the present invention.

Fig. 15 is a graph showing the light emission intensity distribution with respect to the wavelength of white light calculated in Example 4 of the present invention.

It is a chromaticity diagram for demonstrating the synthesis | combining method of white light in Examples 5-7 of this invention.

Fig. 17 is a graph showing the light emission intensity distribution with respect to the wavelength of white light calculated in Example 5 of the present invention.

18 is a graph showing the light emission intensity distribution with respect to the wavelength of white light calculated in Example 6 of the present invention.

19 is a graph showing the light emission intensity distribution with respect to the wavelength of white light calculated in Example 7 of the present invention.

20 is a chromaticity diagram for explaining a method for synthesizing white light in Examples 8 to 11 of the present invention.

Fig. 21 is a graph showing the light emission intensity distribution with respect to the wavelength of white light calculated in Example 8 of the present invention.

Fig. 22 is a graph showing the light emission intensity distribution with respect to the wavelength of white light calculated in Example 9 of the present invention.

Fig. 23 is a graph showing the emission intensity distribution with respect to the wavelength of white light calculated in Example 10 of the present invention.

Fig. 24 is a graph showing the light emission intensity distribution with respect to the wavelength of white light calculated in Example 11 of the present invention.

Fig. 25 is a chromaticity diagram for explaining a method for synthesizing white light in Examples 12 to 14 of the present invention.

Fig. 26 is a graph showing the light emission intensity distribution with respect to the wavelength of white light calculated in Example 12 of the present invention.

Fig. 27 is a graph showing the light emission intensity distribution with respect to the wavelength of white light calculated in Example 13 of the present invention.

Fig. 28 is a graph showing the light emission intensity distribution with respect to the wavelength of white light calculated in Example 14 of the present invention.

To practice the invention  Best form for

EMBODIMENT OF THE INVENTION Hereinafter, although this invention is demonstrated in detail, for example, this invention is not limited to the following examples and can be arbitrarily modified and implemented in the range which does not deviate from the summary of this invention.

[I. Description of light emitting device]

I-1. Overview of Light Emitting Device]

The light emitting device of the present invention includes a light source, a first light emitting portion, a second light emitting portion, and a light shielding portion, and is configured to emit light toward a direction in which light is to be emitted (hereinafter referred to as a "predetermined direction" as appropriate). It is. In general, the light emitting device includes a frame as a base for holding the light source, the first light emitting portion, the second light emitting portion, and the light shielding portion.

I-1-1. frame]

The frame is a base for holding the light source, the first light emitting portion, the second light emitting portion, and the light shielding portion, and the shape and the material thereof are arbitrary.

As a specific example of a frame shape, it can be set as suitable shape according to the use, such as plate shape and cup shape. In addition, among the illustrated shapes, the cup-shaped frame is preferable because the cup-shaped frame can have directivity in the light emitting direction and can effectively use the light emitted by the light emitting device.

Moreover, as a specific example of a frame material, an appropriate thing can be used according to a use, such as inorganic materials, such as a metal, alloy, glass, carbon, and ceramics, and organic materials, such as a synthetic resin.

Moreover, it is preferable to use the thing of favorable heat dissipation for the material of a frame. For example, it is preferable to use a material with high thermal conductivity. Usually, the light source generates heat during use, but if the frame is formed to have good heat dissipation, it is possible to continue using it stably even if heat is generated during use.

Moreover, it is preferable to use an insulating thing for the material of a frame.

However, the surface of the frame on which the light emitted from the light source, the first light emitting part and the second light emitting part touches preferably has a high reflectance of at least one component among the components of the light hitting, particularly in the visible region. As for the reflectance of light, it is more preferable. Therefore, it is preferable that at least the surface on which light hits is formed of a material having high reflectance. As a specific example, what forms the whole frame or the surface of a frame from the raw material (material for injection molding etc.) containing the substance which has high reflectivity, such as glass fiber, alumina powder, titania powder, etc. is mentioned.

In addition, the specific method of increasing the reflectance of the frame surface is arbitrary, and in addition to selecting the material of the frame itself as described above, for example, plating or vapor deposition with a metal or alloy having a high reflectivity such as silver, platinum, aluminum, or the like. By processing, the reflectance of light can also be raised.

In addition, although the part which raises a reflectance may be whole or a part of a frame, it is preferable that the reflectance of the whole surface of the part which the light emitted from a light source, a 1st light emitting part, and a 2nd light emitting part hits normally is high. .

Also, in the frame, electrodes for supplying power to the light source are usually formed.

I-1-2. Light source]

The light source emits excitation light of the light emitting material contained in the first light emitting part and the second light emitting part, and also emits one component of light emitted by the light emitting device. That is, some of the light emitted from the light source is absorbed as excitation light by the light emitting materials in the first light emitting part and the second light emitting part, and the other part is emitted toward the predetermined direction from the light emitting device.

The kind of light source is arbitrary, and a suitable thing can be selected according to the use and structure of a light emitting device. Examples of the light source include light emitting diodes (hereinafter appropriately referred to as "LEDs"), single-sided light emitting or surface emitting laser diodes, electroluminescent devices, and the like, but usually inexpensive LEDs are preferable.

Moreover, the light emission wavelength of the light which a light source emits is arbitrary, and what is necessary is just to use the light source which emits light of a suitable light emission wavelength according to the light emitted to a light emitting device. For example, in the case of emitting white light to a light emitting device, the light emission wavelength of light emitted by the light source is usually 370 nm or more, preferably 380 nm or more, and usually 500 nm or less, preferably 480 nm or less. .

Specific examples of the light source include LEDs using InGaN-based, GaAlN-based, InGaAlN-based, ZnSeS-based semiconductors, etc. crystal-grown on substrates such as silicon carbide, sapphire, gallium nitride, or the like by MOCVD.

In addition, one light source may be used independently and may use 2 or more light sources together. In addition, a light source may be used only by 1 type, and may use 2 or more types together. In particular, in order to increase the color rendering of the light emitting device, it is preferable to form a light source in each of the first light emitting part and the second light emitting part.

Moreover, when forming a light source common to a 1st light emitting part and a 2nd light emitting part, without providing a light source in each of a 1st light emitting part and a 2nd light emitting part, a 1st light emitting part is provided to a light source rather than this 2nd light emitting part. It is desirable to be close. That is, it is preferable that the distance between the light source and the parts which the first light emitting part approaches most is smaller than the shortest distance between the light source and the parts which the second light emitting part approaches most.

For example, when the light blocking portion is configured to block only a part of the light between the first light emitting portion and the second light emitting portion, the light source is formed at a position closer to the second light emitting portion than the first light emitting portion, and the light from the light source is It is assumed that this is first incident on the second light emitting portion. In this case, the second light emitting part emits light using the light from the light source as the excitation light, but since the light from the second light emitting part cannot be used as the excitation light in the first light emitting part, the first light emitting part emits light. There is a possibility that the intensity is insufficient, the light emitted by the second light emitting part becomes too strong, a deviation occurs in the value of the component of the light emitted by the light emitting device, and the color rendering property is lowered. In contrast, when the first light emitting part is formed at a position closer to the light source than the second light emitting part, the light emitted from the light source first enters the first light emitting part. As a result, the first light emitting part emits light first by using light from the light source as excitation light, so that light emission of the first and second light emitting parts is performed smoothly. Therefore, the color variation of the light emitted from the light emitting device is small, and the color rendering property can be further improved.

Also, even when the first light emitting part is disposed at a position closer to the light source than the second light emitting part, the intensity of light emitted from the light source and incident on each of the first light emitting part and the second light emitting part is the first light emitting part and the second light emitting part. It is also related to the area of the surface where each light emitting unit receives light. Therefore, the distance from the light source to each of the first light emitting portion and the second light emitting portion, or the area of the surface receiving each of them, is set so that the intensity of the light received by the first light emitting portion is greater than the intensity of the light received by the second light emitting portion. It is preferable.

Moreover, when attaching a light source to a frame, the specific method is arbitrary, but it can attach using a solder, for example. Although the kind of solder is arbitrary, AuSn, AgSn, etc. can be used, for example. In the case of using solder, it is also possible to supply electric power from an electrode formed on the frame through the solder. In particular, when a large current type LED, a laser diode, or the like in which heat dissipation is important is used as a light source, the solder exhibits excellent heat dissipation. Therefore, it is effective to use solder for installation of the light source.

Moreover, when attaching a light source to a frame by means other than solder | pewter, you may use adhesives, such as an epoxy resin, an imide resin, and an acrylic resin, for example. In this case, it is also possible to mix the conductive fillers such as silver particles and carbon particles with the adhesive to form a paste so that the adhesive can be supplied with electricity to the light source as in the case of using solder. Moreover, when these conductive fillers are mixed, since heat dissipation also improves, it is preferable.

Moreover, the power supply method to a light source is also arbitrary, In addition to energizing the solder or adhesive agent mentioned above, you may connect a light source and an electrode by wire bonding, and supply electric power. There is no restriction | limiting in the wire used at this time, A raw material, a dimension, etc. are arbitrary. For example, metal, such as gold and aluminum, can be used as a raw material of a wire, Moreover, although the thickness can be normally 20 micrometers-40 micrometers, a wire is not limited to this.

Moreover, as an example of another method of supplying electric power to a light source, the method of supplying electric power to a light source by flip-chip mounting using bump is mentioned.

I-1-3. 1st light emitting part and 2nd light emitting part]

The first light emitting portion is excited by the light emitted by the light source, and is formed to contain at least one light emitting material that emits light containing a component having a longer wavelength than the light emitted by the light source. There is no restriction | limiting in particular in the shape of this 1st light emitting part, Moreover, you may form independently in one point, and may divide and form in two or more places. In addition, the light emitting material used for a 1st light emitting part is explained in full detail later.

In the first light emitting portion, the light emitted from the light source is received, whereby the light emitting material emits light using the received light as the excitation light. The emitted light is emitted outside the light emitting device as a component of the light emitted by the light emitting device. However, when the light shielding part shields only a part of the light emitted from the first light emitting part toward the second light emitting part, part of the light from the first light emitting part becomes excitation light of the light emitting material of the second light emitting part.

On the other hand, the second light emitting part is formed by containing at least one light emitting material that is excited by the light emitted from the light source and the light emitted by the first light emitting part and emits light containing a component having a longer wavelength than the light emitted by the first light emitting part. . There is no restriction | limiting in particular also in the shape of this 2nd light emitting part, Moreover, you may form independently in 1 point, and may divide and form in 2 or more points. In addition, the light emitting material used in the second light emitting portion will be described later in detail.

In the second light emitting portion, the light emitted from the light emitted from the light source is received, whereby the light emitting material emits light using the received light as the excitation light. In addition, when light emitted from the first light emitting portion is incident on the second light emitting portion, the light emitting material emits light in the second light emitting portion with the incident light from the first light emitting portion also serving as excitation light. The light emitted is emitted to the outside of the light emitting device as a component of the light emitted by the light emitting device.

Moreover, it is preferable that both the said 1st light emitting part and the 2nd light emitting part open to the exterior in the light emission surface. Here, the light emitting surface means a surface on which the light emitting device emits light toward a predetermined direction. Therefore, the light emitted from the light source, the first light emitting portion and the second light emitting portion is emitted from the light emitting surface toward the predetermined direction. Moreover, the shape of a light exit surface is arbitrary, It is preferable to set it as a suitable shape according to the use, such as a plane, a curved surface, an uneven surface. In general, even when light emitted from the light emitting device is emitted in a plurality of directions or in a radial shape in a predetermined angle range, the strongest light is emitted in a predetermined direction.

Moreover, that the 1st light emitting part and the 2nd light emitting part open | released means that the light emitted from a 1st, 2nd light emitting part toward a predetermined direction is emitted without being shielded by another member. More specifically, the light emitted from the first light emitting part in a predetermined direction is not shielded by the light source, the light shielding part, the second light emitting part and the frame (if the light emitting device has a frame) and the outside of the light emitting device. Light emitted from the second light emitting part in a predetermined direction is not shielded by the light source, the light shielding part, the first light emitting part and the frame (if the light emitting device is provided with the frame) and is not shielded by the light emitting device. It is emitted to the outside. In addition, even when a protective layer is formed on the light output surface or a cover is attached to the light emitting device, the light emitted from the first and second light emitting parts is emitted through the other member to the outside of the light emitting device. As long as other members, such as a cover and a cover, can transmit the emitted light, it is assumed that the 1st, 2nd light emitting part is open.

When the first light emitting part and the second light emitting part are opened at the light exit surface as described above, the light emitted from the first light emitting part and the light emitted from the second light emitting part are respectively absorbed by different light emitting materials or applied to other members. The degree to which the strength is weakened by shielding can be reduced (or eliminated). Therefore, the luminous efficiency of a light emitting device can be improved, the dispersion | variation in the light component emitted from a light emitting device can be made small, and the color rendering property of a light emitting device can be improved. In addition, since the light can be emitted from the light emitting device using three primary colors of blue light, red light, and green light, the light source, the first light emitting part, and the second light emitting part can be selected appropriately, thereby achieving excellent color reproducibility of the light emitting device of the present invention. can do.

I-1-4. Shading part]

The light shielding portion prevents light emitted from the first light emitting portion from being incident on the second light emitting portion. The light shielding part should be able to prevent at least a part of the light emitted from the first light emitting part from being incident on the second light emitting part, but is usually sufficient to endure practically the light emitted from the light emitting device in a predetermined direction. The light emitted from the first light emitting portion may be prevented from entering the second light emitting portion to such an extent that high light emission efficiency and color rendering property can be exhibited. In addition, it is preferable that all the light emitted from the first light emitting part does not enter the second light emitting part. As a result, since light emitted from the first light emitting portion can be prevented from being consumed as excitation light of the second light emitting portion, a decrease in the intensity of light emitted by the first light emitting portion can be suppressed, and the luminous efficiency and color rendering property of the light emitting device can be suppressed. You can increase both.

At this time, the light shielding portion is preferably formed so as to reflect at least a part of the light emitted from the first light emitting portion. More preferably, the light is emitted from the first light emitting portion and is formed to reflect all of the light that reaches the light blocking portion. Thereby, the light emitted from the first light emitting portion can be used effectively, and the light emission efficiency and the color rendering of the light emitting device can be further improved.

In this regard, the light shielding portion is preferably formed so as to reflect at least a part of the light emitted from the second light emitting portion, and is formed so as to reflect all of the light emitted from the second light emitting portion and touching the light blocking portion. It is more preferable. As a result, even light emitted from the second light emitting portion can be effectively used, and the light emission efficiency and color rendering property of the light emitting device can be further improved.

In addition, the light shielding portion is preferably formed so as to reflect at least a part of the light emitted from the light source, and more preferably formed so as to reflect all of the light emitted from the light source and touching the light shielding portion. Accordingly, even light emitted from the light source can be effectively used, and the luminous efficiency and color rendering property of the light emitting device can be further improved.

Specifically, the reflectance of at least one component among the components of the light (that is, light emitted from any one of the light source, the first light emitting portion, and the second light emitting portion) of at least part of the surface of the light shielding portion is increased. It is preferable, and it is more preferable that especially the reflectance of the light of visible light whole is high. Therefore, as with the frame, it is preferable that at least the surface to which light hits is formed of a material having high reflectance. As a specific example, what forms the whole light-shielding part or the surface of a light-shielding part with the raw material (material for injection molding etc.) containing the substance which has high reflectivity, such as glass fiber, alumina powder, titania powder, etc. is mentioned.

Moreover, the specific method of improving the reflectance of the surface of a light shielding part is arbitrary, In addition to selecting the material of the light shielding part itself as mentioned above, plating process is carried out by the metal or alloy which has high reflectances, such as silver, platinum, aluminum, for example. By doing this, the reflectance of the light can also be increased.

In addition, although the part which raises a reflectance may be whole or a part of light shielding parts, it is preferable that the reflectance of the whole surface of the part to which the light emitted from a light source, a 1st light emitting part, and a 2nd light emitting part hits normally is high.

The shape of the light shielding portion can be formed in any shape as long as it can prevent at least a part of the light emitted from the first light emitting portion from being incident on the second light emitting portion. For example, you may form as a member which partitions between a 1st light emission part and a 2nd light emission part, a mesh shape, a mesh shape, etc. In addition, the light shielding portion may be formed integrally with the frame or may be formed separately. In general, however, it is preferable to set the position of the light shielding portion so that the light emitting device can emit the target light in accordance with the light emission intensity of the first light emitting portion and the second light emitting portion.

It is preferable to form a plurality of recesses (cup-shaped recesses, etc.) in the frame, and to form a light source, a first light emitting unit or a second light emitting unit for each recess, in terms of facilitating manufacture of the light emitting device. Do. In this case, the wall portion of the frame partitioning each of the recesses functions as a light shielding portion. The display device using this embodiment is described in detail in the third embodiment.

Further, the material of the light shielding portion is not limited as long as it can prevent at least a part of the light emitted from the first light emitting portion from being incident on the second light emitting portion, and may be formed of any material. For example, a suitable thing can be used according to a use, such as inorganic materials, such as a metal, an alloy, and glass, organic materials, such as a synthetic resin and carbon. Especially, the material which reflects the light which a 1st light emitting part and a 2nd light emitting part emit, and does not absorb the light which a 1st light emitting part and a 2nd light emitting part emit | emit as mentioned above is preferable normally.

In the light emitting device of the present invention, a light shielding portion is formed between the first light emitting portion and the second light emitting portion, thereby preventing the light emitted from the first light emitting portion from being incident on the second light emitting portion. Thereby, the luminous efficiency and color rendering of the light emitting device of the present invention can be improved. Hereinafter, the structure will be described in detail.

Conventionally, when a part of the light emitted from the first light emitting part is emitted toward the second light emitting part, the light emitted from the first light emitting part is incident on the second light emitting part, and the light emitting material from the first light emitting part is emitted from the first light emitting part. The light was absorbed as excitation light. Accordingly, the light emitted from the first light emitting portion was consumed in the second light emitting portion. For this reason, the intensity of light from the first light emitting portion to be emitted outside the light emitting device is lowered, the luminous flux of light emitted from the light emitting device is reduced, and the luminous efficiency is lowered. In addition, since the light emitted from the first light emitting part is consumed in the second light emitting part, the balance of the light component emitted from the light emitting device is disturbed, thereby reducing the color reproducibility of the light emitting device.

In addition, when the color of the light emitted from the light emitting device is intended to be the desired color, in the configuration such as Patent Document 1, in order to supplement the light from the first light emitting portion absorbed by the second light emitting portion, the light emitting material of the second light emitting portion It was necessary to increase the ratio of the light emitting material with respect to the first light emitting portion. However, since the color rendering property of the light emitted from the light emitting device is determined according to the type and use ratio of the light emitting material to be used, since the use ratio of the light emitting material tends to deviate greatly from the optimum value in the light emitting device having the configuration as in Patent Document 1, It was easy to fall also about the color rendering of light.

In contrast, in the light emitting device of the present invention, since the light shielding portion prevents the light emitted from the first light emitting portion from being incident on the second light emitting portion, the light from the first light emitting portion is absorbed by the second light emitting portion. The strength can be suppressed from weakening. Therefore, the luminous efficiency of a light emitting device can be improved than before.

Moreover, since it can suppress that a 2nd light emitting part absorbs and emits light emitted from the 1st light emitting part, the deviation of the light component emitted from a light emitting device can be made small, and the color rendering property of a light emitting device can also be improved. As a result, the color rendering and color reproducibility of the light emitting device may be improved.

Further, any excitation light (mainly light from a light source) can be supplied to the first light emitting part and the second light emitting part, and light emitted from the light source, the first light emitting part and the second light emitting part can be emitted out of the light emitting device. If it can, the arrangement | positioning, the dimension, a shape, etc. of each member which comprise a light emitting device can be arbitrarily set.

For example, the first light emitting part, the second light emitting part, the light source, and the frame may be arranged at a distance to have a space therebetween. As a specific example, a gap may be formed between the first light emitting portion and the second light emitting portion. Moreover, you may make a space | gap generate | occur | produce between one or both of a 1st light emitting part and a 2nd light emitting part, and a light source. Moreover, you may make a space | gap generate | occur | produce between one or both of a 1st light emitting part and a 2nd light emitting part, and a light shielding part.

In the case where the distance between the first light emitting portion and the second light emitting portion, one or both of the first light emitting portion and the second light emitting portion, and the light source is such that they do not come into contact with each other, other members may be formed therebetween. . At this time, when the material which transmits desired light, such as resin, such as glass, an epoxy resin, and a silicon resin, is used as a material of other members, a light beam can be made high and it is preferable. As a specific example, when a protective layer made of transparent resin is formed around the entire light source, a state in which the luminous flux of light from the light source is maintained high even though a distance is generated between the light source and the first light emitting part and the second light emitting part. In this way, since it is possible to reliably supply the excitation light to the first light emitting portion and the second light emitting portion, it becomes possible to protect the light source without lowering the intensity of the light emitted by the light emitting device.

As described above, the first light emitting part and the second light emitting part may have different sizes.

In addition, the light emitting device of the present invention may include members other than the light source, the first light emitting portion, the second light emitting portion, and the frame described above.

For example, the cover for protecting the light emitting device itself may be provided.

Further, for example, a light guide member such as a mirror, a prism, a lens, and an optical fiber for changing the direction of light emitted from the light emitting device may be provided.

In addition, a heat sink for dissipating heat generated by the light emitting device may be provided.

For example, in order to diffuse each component of the light emitted from a light emitting device, and to prevent the color nonuniformity of visible light etc., a light diffusion layer etc. may be formed outside the light emission surface of a light emitting device.

I-2. Composition of Light Emitting Part]

The light emitting material used in the light emitting device of the present invention is not limited as long as it can absorb excitation light and emit light containing longer wavelength components than the absorbed excitation light. In the case where the first light emitting portion and the second light emitting portion are formed using a light emitting material, the light emitting material is usually used in combination with a binder.

[I-2-1. Luminescent material]

The light emitting material can be suitably selected and used according to the use of the light emitting device. The light emission itself is not limited even if the light emission is performed by any mechanism such as fluorescence or phosphorescence. In addition, in each of the first light emitting portion and the second light emitting portion, the light emitting material may be used alone, or two or more thereof may be used in any combination and ratio. However, the light emitting material used for the first light emitting part is selected to be excited by the light emitted by the light source and emit light containing a component having a longer wavelength than the light emitted by the light source. It is selected to emit light which is excited by the light emitted by the first light emitting part and which contains a component having a longer wavelength than the light emitted by the first light emitting part.

The light emitting material has a wavelength of 350 nm or more, preferably 400 nm or more, more preferably 430 nm or more, and usually 600 nm or less, preferably 570 nm or less, more preferably 550 nm as an excitation light. It is preferable to absorb the following light.

In addition, the light emitting material has a wavelength of light that is usually 400 nm or more, preferably 450 nm or more, more preferably 500 nm or more, and usually 750 nm or less, preferably 700 nm or less, more preferably 670 It is preferable that it is nm or less.

Among them, in the case of a light emitting material used in the first light emitting portion, the wavelength of the excitation light is usually 350 nm or more, preferably 400 nm or more, more preferably 430 nm or more, and usually 520 nm or less, preferably Preferably it absorbs light below 500 nm, More preferably, below 480 nm.

In the light emitting material used for the first light emitting portion, the wavelength of light emitted is usually 400 nm or more, preferably 450 nm or more, more preferably 500 nm or more, and usually 600 nm or less, preferably 570 nm. Hereinafter, More preferably, it is 550 nm or less.

On the other hand, in the case of a light emitting material used in the second light emitting portion, the wavelength of the excitation light is usually 400 nm or more, preferably 450 nm or more, more preferably 500 nm or more, and usually 600 nm or less, preferably It is preferable to absorb light of 570 nm or less, More preferably, 550 nm or less.

In the light emitting material used for the second light emitting portion, the wavelength of light emitted is usually 550 nm or more, preferably 580 nm or more, more preferably 600 nm or more, and usually 750 nm or less, preferably 700 nm. Hereinafter, More preferably, it is 670 nm or less.

In addition, it is preferable that the light emitting material has a light emission efficiency of 40% or more, preferably 45% or more, more preferably 50% or more, even more preferably 55% or more, and most preferably 60% or more. desirable. The luminous efficiency shown here is a value expressed as a product of quantum absorption efficiency and internal quantum efficiency.

Hereinafter, a light emitting material suitable for use in the light emitting device of the present invention is illustrated and described for each light emitting portion. However, the light emitting material is not limited to the following examples, and any of the above-described light emitting materials can also be arbitrarily selected within the scope of the present invention as to which of the first light emitting portion and the second light emitting portion, respectively.

(Example of the thing preferable for the light emitting material of a 1st light emission part)

(1st example of 1st light emission part)

As a 1st example of the preferable light emitting substance for the light emitting substance of a 1st light emitting part, the fluorescent substance represented by following formula (1) is mentioned.

M ¹ _a M ² _b M ³ _c O _d . Formula (1)

In the formula (1), M ¹ represents a divalent metal element, M ² represents a trivalent metal element, M ³ represents a tetravalent metal element, and a, b, c, and d are the numbers in the following ranges, respectively.

a

3.3 2.7

a

3.3

b

2.2 1.8

b

2.2

c

3.3 2.7

c

3.3

d

13.0 11.0

d

13.0

M ¹ in the formula (1) is a divalent metal element, but is preferably at least one selected from the group consisting of Mg, Ca, Zn, Sr, Cd, and Ba, in terms of luminous efficiency, and Mg, Ca Or Zn, more preferably Ca. In this case, Ca may be a single type or a complex type with Mg. Basically, M ¹ is preferably made of the elements considered above, it is preferable, in a range that does not impair the performance, may contain another bivalent metal element.

In addition, but M ² is a metal element trivalent in the formula (1), is in the same plane as the M ^1, species, at least one selected from the group consisting of Al, Sc, Ga, Y, In, La, Gd and Lu It is preferred, more preferably Al, Sc, Y or Lu, with Sc being particularly preferred. In this case, Sc may be a single type or a complex type with Y or Lu. Basically, M ² is preferably will be done with the elements deemed above, preferred, in a range that does not impair the performance, may contain another trivalent metal element.

In addition, although M <^3> in said Formula (1) is a tetravalent metal element, it is preferable to contain at least Si from the same surface as M <^1> , M <^2> . In addition, it is preferable that usually 50 mol% or more, preferably 70 mol% or more, more preferably 80 mol% or more, and particularly preferably 90 mol% or more of the tetravalent metal element represented by M ³ is Si.

In the formula (1), Specific examples of the tetravalent metal elements other than Si M ³ are, Ti, Ge, Zr, Sn and Hf preferably at least one member selected from the group, Ti, Zr, and consisting of Sn and It is more preferable that it is at least 1 sort (s) chosen from the group which consists of Hf, and it is especially preferable that it is Sn. In particular, it is preferable that M <^3> is Si. Basically, although M <^3> consists of an element considered preferable above, it may contain the other tetravalent metal element in the range which does not impair performance.

In the present specification, it should contain in a range that does not impair the performance, the above M ^1, M ^2, M ³ are as for each, and more typically 10 mol% or less, preferably 5 mol% or less, preferably It means to contain in 1 mol% or less.

a

3.3, 1.8

b

2.2, 2.7

c

3.3, 11.0

d

13.0 범위의 수인 것이 바람직하다. The crystal structure of the above-mentioned phosphor is usually a garnet crystal structure, but in general, this is of a body-centered cubic lattice in which a in Formula (1) is 3, b is 2, c is 3, and d is 12. It is a decision. In this case, the element of the light emitting center ion is replaced with the position of the crystal lattice of any one of the metal elements of M ¹ , M ² , M ³ , or arranged in the gap between the crystal lattice. ), A may be 3, b is 2, c is 3, and d may not be 12. Thus, a, b, c, and d are each 2.7

a

3.3, 1.8

b

2.2, 2.7

c

3.3, 11.0

d

It is preferably a number in the range of 13.0.

In addition, the light emitting center ions contained in the compound matrix of the crystal structure contain at least Ce, and in order to finely adjust the light emitting characteristics, Cr, Mn, Fe, Co, Ni, Cu, Pr, Nd, Sm, Eu, It is also possible to contain 1 or more types of 2-4 tetravalent elements chosen from the group which consists of Tb, Dy, Ho, Er, Tm, and Yb. In particular, it is preferable to contain 1 or more types of 2-4 tetravalent elements selected from the group which consists of Mn, Fe, Co, Ni, Cu, Sm, Eu, Tb, Dy, and Yb, and it is bivalent Mn, 2-3 trivalent Eu. Or trivalent Tb can be particularly preferably used.

This phosphor is usually excited by light in the wavelength range of 420 nm to 480 nm. The emission spectrum has a peak at 500 to 510 nm and a wavelength component of 450 to 650 nm.

In addition, specific examples of the phosphors described above include Ca ₃ Sc ₂ Si ₃ O ₁₂ : Ce, Ca ₃ (Sc, Mg) ₂ Si ₃ O ₁₂ : Ce, and the like.

(2nd example of 1st light emission part)

As a 2nd example of the preferable luminescent substance used for a 1st light emitting part, fluorescent substance represented by following formula (2) is mentioned.

M ¹ _a M ² _b M ³ _c O _d . Formula (2)

In the formula (2), M ¹ represents an activator element containing at least Ce, M ² represents a divalent metal element, M ³ represents a trivalent metal element, and a, b, c and d each represent the following ranges: Is the number of.

a

0.2 0.0001

a

0.2

b

1.2 0.8

b

1.2

c

2.4 1.6

c

2.4

d

4.8 3.2

d

4.8

M ¹ in the formula (2) contains at least Ce as an activator element contained in a crystal matrix described later. Moreover, the group which consists of Cr, Mn, Fe, Co, Ni, Cu, Ce, Pr, Nd, Sm, Eu, Tb, Dy, Ho, Er, Tm, and Yb for the purpose of photoluminescence, chromaticity adjustment, increase or decrease, etc. It can contain at least 1 sort (s) of 2-4 tetravalent elements chosen from the above.

a

0.2 이다. a 의 값이 지나치게 작으면 형광체의 결정 모체 중에 존재하는 발광 중심 이온이 지나치게 적어 발광 강도가 작아지는 경향이 있다. 한편, a 의 값이 지나치게 크면 농도 소광에 의해 발광 강도가 작아지는 경향이 있다. 따라서, 발광 강도면에서는, a 는 바람직하게는 0.0005 이상, 보다 바람직하게는 0.002 이상, 또 바람직하게는 0.1 이하, 보다 바람직하게는 0.04 이하가 바람직하다. 또, Ce 의 함유량이 높아짐에 따라서 발광 피크 파장이 장파장측으로 시프트하여 시감도가 높은 녹색 발광량이 상대적으로 증가하기 때문에, 발광 강도와 발광 피크 파장의 밸런스면에서, a 는 통상적으로 0.004 이상, 바람직하게는 0.008 이상, 보다 바람직하게는 0.02 이상, 또 통상적으로 0.15 이하, 바람직하게는 0.1 이하, 보다 바람직하게는 0.08 이하가 더욱 바람직하다. In the formula (2), the value a representing the content of the activator element M ¹ is 0.0001

a

0.2. When the value of a is too small, there is a tendency that the emission center ions present in the crystal matrix of the phosphor are too small and the emission intensity is small. On the other hand, when the value of a is too large, the light emission intensity tends to decrease due to concentration quenching. Therefore, from the viewpoint of the luminescence intensity, a is preferably 0.0005 or more, more preferably 0.002 or more, and preferably 0.1 or less, and more preferably 0.04 or less. In addition, since the emission peak wavelength shifts to the longer wavelength side and the amount of green light emission having high visibility is relatively increased as the Ce content increases, a is usually 0.004 or more, preferably in terms of the balance between the emission intensity and the emission peak wavelength. It is more preferably 0.008 or more, more preferably 0.02 or more, and usually 0.15 or less, preferably 0.1 or less, and more preferably 0.08 or less.

In addition, although M <^2> in said Formula (2) is a divalent metal element, it is preferable that it is at least 1 sort (s) chosen from the group which consists of Mg, Ca, Zn, Sr, Cd, and Ba from a viewpoint of luminous efficiency, etc., Mg It is more preferable that it is Ca, or Sr, and it is especially preferable that 50 mol% or more of the element of M <^2> is Ca.

In addition, although M <^3> in said Formula (2) is a trivalent metal element, at least 1 selected from the group which consists of Al, Sc, Ga, Y, In, La, Gd, Yb, and Lu from the same point as M <^2>. It is preferably a species, more preferably Al, Sc, Yb or Lu, more preferably Sc, or Sc and Al, or Sc and Lu, particularly preferably at least 50 mol% of the elements of M ³ being Sc Do.

Since the host crystal of the phosphor is, in general, divalent metal elements consisting of M ³ and oxygen of M ² and trivalent metal elements, the composition formula M ² crystals represented by M ³ ₂ O _4, the chemical composition is, in general, And b in Formula (2) are 1, c is 2, and d is 4. However, in this case, the activator element is Ce,, the formula (2) or the like arranged in the gap between the substituted position of M ² or the determination of M ³ which one of the metal elements of the lattice, or, the crystal lattice In some cases, b may be 1, c is 2, and d may not be 4.

Therefore, in the formula (2), b is usually 0.8 or more, preferably 0.9 or more, and usually 1.2 or less, preferably 1.1 or less. C is usually 1.6 or more, preferably 1.8 or more, and usually 2.4 or less, preferably 2.2 or less. D is usually 3.2 or more, preferably 3.6 or more, and usually 4.8 or less, preferably 4.4 or less.

In addition, in said Formula (2), although M <^2> and M <^3> represent bivalent and trivalent metal elements, respectively, if there is no fundamental difference in a luminescence characteristic, a crystal structure, etc., it is extremely of M <^2> and / or M <^3> . It is also possible to adjust the charge balance and the like by using a part as a metal element of any valence of monovalent, tetravalent, or pentavalent, and also a small amount of anions such as halogen elements (F, Cl, Br, I). ), Nitrogen, sulfur, selenium and the like may be contained in the compound.

This phosphor is excited by light in the wavelength range of 420 nm to 480 nm, and is most efficient at 440 to 470 nm. The emission spectrum has a peak at 490-550 nm and a wavelength component of 450-700 nm.

(Other examples of the first light emitting part)

n<1.5) 로 나타나는 Eu 에 의해 부활된 α 사이알론 등의 파장 500㎚∼600㎚ 에 발광 피크를 갖는 물질을 들 수 있지만, 이들에 한정되지 않는다.Other examples of light emitting materials suitable for use in the first light emitting portion include Y ₃ (Al, Ga) ₅ O ₁₂ : Ce, (Ba, Ca, Sr) MgAl ₁₀ O ₁₇ : Eu, (Ba, Mg , Ca, Sr) ₅ (PO) ₄ C: Eu, (Ba, Ca, Sr) ₃ MgSi ₂ O ₈ : A substance having an emission peak at 400 nm to 500 nm such as Eu, or (Ba, Ca, Sr) MgAl ₁₀ O ₁₇ : Eu, Mn, (Ba, Ca, Sr) Al ₂ O ₄ : Eu, (Ba, Ca, Sr) Al ₂ O: Eu, Mn, (Ca, Sr) Al ₂ O ₄ : Eu, General formula Ca _x Si _{12- (m + n)} Al _{(m + n)} O _n N _{16 -n} : Eu (where 0.3 <x <1.5, 0.6 <m <3, 0

Although the substance which has a light emission peak in wavelength 500nm -600nm, such as alpha sialon revived by Eu represented by n <1.5), is mentioned, It is not limited to these.

In addition, the above-mentioned phosphor may be used individually by 1 type, and may use 2 or more types together by arbitrary combinations and a ratio.

However, among the illustrated phosphors, those having a garnet crystal structure are preferable because they are hardly deteriorated with respect to heat, light and water. Specific examples of the phosphor having such a garnet crystal structure include phosphors exemplified as the first example of the phosphor emitting green light, and Y ₃ (Al, Ga) ₅ O ₁₂ : Ce.

(Example of what is suitable for the light emitting material of the second light emitting part)

(1st example of 2nd light emission part)

As a 1st example of the light emitting material suitable for the light emitting material of a 2nd light emitting part, fluorescent substance represented by following formula (3) is mentioned.

M _a A _b D _c E _d X _e . Formula (3)

In the formula (3), M is one or two or more elements selected from the group consisting of Mn, Ce, Pr, Nd, Sm, Eu, Tb, Dy, Ho, Er, Tm, Yb, and at least Eu It represents containing, A represents 1 type or 2 or more types of elements chosen from the group which consists of bivalent metal elements other than M element, D is 1 type or 2 or more types selected from the group which consists of tetravalent metal elements. An element is represented, E represents 1 type or 2 or more types of elements chosen from the group which consists of trivalent metal elements, and X represents 1 type or 2 or more types of elements chosen from the group which consists of O, N, and F.

In addition, in said Formula (3), a, b, c, d, e are the numbers of the following ranges, respectively.

a

0.10.00001

a

0.1

a + b = 1

c

40.5

c

4

d

80.5

d

8

e0.8 × (2/3 + 4/3 × c + d)

e

1.2×(2/3+4/3×c+d) e

1.2 × (2/3 + 4/3 × c + d)

In the formula (3), M contains at least Eu, and one or two selected from the group consisting of Mn, Ce, Pr, Nd, Sm, Eu, Tb, Dy, Ho, Er, Tm, Yb Although it is the above element, it is preferable that it is 1 type, or 2 or more types of elements chosen from the group which consists of Mn, Ce, Sm, Eu, Tb, Dy, Er, Yb among these, and it is more preferable that it is Eu.

Moreover, in said Formula (3), A is 1 type, or 2 or more types of elements chosen from the group which consists of bivalent metal elements other than M element, Especially, it selects from the group which consists of Mg, Ca, Sr, and Ba. It is preferable that it is 1 type, or 2 or more types of elements, and it is more preferable that it is Ca or a complex system of Ca and Sr.

In Formula (3), D is one or two or more elements selected from the group consisting of tetravalent metal elements, and among them, D is selected from the group consisting of Si, Ge, Sn, Ti, Zr, and Hf. It is preferable that it is 1 type, or 2 or more types of elements, and it is more preferable that it is Si.

In Equation (3), E is one or two or more elements selected from the group consisting of trivalent metal elements, and among them, B, Al, Ga, In, Sc, Y, La, Gd, It is preferable that it is 1 type, or 2 or more types of elements chosen from the group which consists of Lu, and it is more preferable that it is Al.

In addition, in said Formula (3), X is 1 type, or 2 or more types of elements chosen from the group which consists of O, N, and F, Especially, it is preferable that it consists of N or N and O.

In addition, in said Formula (3), a shows content of the element M used as a light emission center, and ratio of the number of atoms of M and (M + A) in the fluorescent substance a {However, a = (number of atoms of M) / (The number of atoms of M + the number of atoms of A)} is preferably 0.00001 or more and 0.1 or less. If the value of a is smaller than 0.00001, the number of M serving as the light emission center is small, which may lower the light emission luminance. If the value a is larger than 0.1, concentration quenching may occur due to interference between M ions, and the luminance may decrease. Especially, when M is Eu, since a luminescence brightness becomes high, it is preferable that a value is 0.002 or more and 0.03 or less.

c

4 로 나타나는 양이다. 바람직하게는 0.5

c

1.8, 더욱 바람직하게는 c=1 이 좋다. c 가 0.5 보다 작은 경우 및 4 보다 큰 경우에는, 발광 휘도가 저하될 우려가 있다. 또, 0.5

c

1.8 의 범위는 발광 휘도가 높고, 그 중에서도 c=1 이 특히 발광 휘도가 높다.In addition, in said Formula (3), c is content of D elements, such as Si, and is 0.5

c

The amount represented by four. Preferably 0.5

c

1.8, more preferably c = 1. When c is smaller than 0.5 and larger than 4, there is a fear that the luminescence brightness is lowered. 0.5

c

In the range of 1.8, the light emission luminance is high, and c = 1 is particularly high in the light emission luminance.

d

8 로 나타나는 양이다. 바람직하게는 0.5

d

1.8, 더욱 바람직하게는 d=1 이 좋다. d 값이 0.5 보다 작은 경우 및 8 보다 큰 경우에는 발광 휘도가 저하될 우려가 있다. 또, 0.5

d

1.8 의 범위는 발광 휘도가 높고, 그 중에서도 d=1 이 특히 발광 휘도가 높다.In addition, in said Formula (3), d is content of E elements, such as Al, and is 0.5

d

This is the amount represented by 8. Preferably 0.5

d

1.8, more preferably d = 1. When the d value is smaller than 0.5 and larger than 8, there is a fear that the luminescence brightness is lowered. 0.5

d

In the range of 1.8, the light emission luminance is high, among which d = 1 is particularly high.

In addition, in said Formula (3), e is content of X elements, such as N, and is 0.8 * {(2/3) + (4/3) * c + d} or more and 1.2 * {(2/3) + It is the quantity shown below (4/3) xc + d}. More preferably, e = 3 is good. When the value of e is out of the said range, there exists a possibility that light emission luminance may fall.

Among the above compositions, the luminescent brightness is high and the preferred composition contains at least Eu in M element, Ca in A element, Si in D element, Al in E element, and N in X element. It contains. Especially, the inorganic compound whose M element is Eu, A element is Ca, D element is Si, E element is Al, and X element is N or a mixture of N and O is preferable.

This phosphor is excited by light having a wavelength of at least 580 nm or less, and is particularly efficient in the wavelength range of 400 nm to 550 nm, and therefore absorbs light emitted by the first light emitting part well. The emission spectrum has a peak in the wavelength range of 580 nm to 720 nm.

(2nd example of 2nd light emission part)

As a 2nd example of the light emitting material suitable for the light emitting material of a 2nd light emitting part, fluorescent substance represented by following formula (4) is mentioned.

Eu _a Ca _b Sr _c M _d S _e . Formula (4)

In said Formula (4), M represents at least 1 sort (s) of element chosen from Ba, Mg, Zn, and a, b, c, d, e are the numbers of the following ranges, respectively.

a

0.020.0002

a

0.02

b

0.99980.3

b

0.9998

d

0.10

d

0.1

a + b + c + d = 1

e

1.10.9

e

1.1

In terms of thermal stability, the preferred range of a in the formula (4) is usually 0.0002 or more, preferably 0.0004 or more, and usually 0.02 or less.

In terms of temperature characteristics, when speaking about the preferable range of a in said Formula (4), it is usually 0.0004 or more, and usually 0.01 or less, Preferably it is 0.007 or less, More preferably, it is 0.005 or less, More preferably, 0.004 or less are more preferable.

In terms of luminescence intensity, the preferred range of a in the above formula (4) is usually 0.0004 or more, preferably 0.001 or more, and usually 0.02 or less, preferably 0.008 or less. There is a tendency that the content of the luminescent center ion Eu ^{2 +} that is less than the above range, a tendency that the emission intensity be small and, on the other hand, even if larger than the above range, by the called concentration quenching phenomenon also reduces the emission intensity.

When speaking about the preferable range of a in said Formula (4) which combines all of thermal stability, temperature characteristic, and luminescence intensity, the range of 0.0004 or more, Preferably it is 0.001 or more and usually 0.004 or less is preferable.

Moreover, in the basic crystal Eu _a Ca _b Sr _c M _d S _e of the above formula (4), although the molar ratio of the cation site occupied by Eu, Ca, Sr or M and the anion site occupied by S is 1: 1, the cation deficiency Even if some anion deficiency occurs, there is no significant effect on the fluorescence performance of the present invention, so that the basic crystal of the formula (4) can be used in the molar ratio e of the anion site occupied by S in the range of 0.9 to 1.1.

d

0.1 의 비율로 상기 식 (4) 의 화학 물질 중에 함유하고 있어도, 본 발명의 목적을 달성할 수 있다.In the phosphor of formula (4), M, which represents at least one element selected from Ba, Mg, and Zn, is not necessarily an element in the present invention, but is 0 at a molar ratio d of M.

d

Even if it contains in the chemical substance of said Formula (4) in the ratio of 0.1, the objective of this invention can be achieved.

Moreover, even if it contains elements other than Eu, Ca, Sr, Ba, Mg, Zn, S in the chemical substance of said Formula (4) in an amount of 1% or less as an impurity, there is no problem in use.

This phosphor is excited by light of 600 nm or less, and is particularly efficient at 400 nm to 550 nm, and therefore absorbs light emitted by the first light emitting part well. The emission spectrum has a peak at 620 nm to 680 nm.

(Other examples of the second light emitting part)

n<1.5) 로 나타나는 Eu 에 의해 부활된 α 사이알론, Ca₂Si₅N₈:Eu, CaSi₇N₁₀:Eu, 형광을 발하는 유로퓸 착물 등을 사용할 수 있다.Other examples of the light emitting material suitable for use in the second light emitting portion are not particularly limited as long as the light emitting wavelength is 550 nm to 750 nm and the light emitting wavelength is longer than that of the first light emitting portion. _x Si _{12- (m + n)} Al _{(m + n)} O _n N _{16 -n} : Eu (where 0.3 <x <1.5, 0.6 <m <3, 0

α sialon, Ca ₂ Si ₅ N ₈ : Eu, CaSi ₇ N ₁₀ : Eu, fluorinated europium complexes, etc., which are revived by Eu represented by n <1.5), can be used.

In addition, the above-mentioned phosphor may be used individually by 1 type, and may use 2 or more types together by arbitrary combinations and a ratio.

(Particle size of luminescent material)

The luminescent material is usually used in the form of particles. At this time, the particle diameter of the luminescent material particles is usually 150 µm or less, preferably 50 µm or less, more preferably 20 µm or less, still more preferably 10 µm or less, most preferably 5 µm or less. If it exceeds this range, the deviation of the light emission color of a light emitting device will become large, and when mixing a light emitting material and a sealing material, it may become difficult to apply | coat a light emitting material uniformly. Moreover, it is 0.001 micrometer or more normally, Preferably it is 0.01 micrometer or more, More preferably, it is 0.1 micrometer or more, More preferably, it is 1 micrometer or more, Most preferably, it is 2 micrometers or more. If it is less than this range, luminous efficiency will fall.

The volume ratio of the light emitting material to the light emitting material of the second light emitting part is arbitrary, but is usually 0.05 or more, preferably 0.1 or more, more preferably 0.2 or more, and usually 1 or less, preferably 0.8 or less, More preferably, it is 0.5 or less. Even if this ratio is too large or too small, preferable white light emission is hard to be obtained.

In the case where the first light emitting portion and the second light emitting portion are formed without using a binder, for example, the light emitting material is fired to produce a fired body, and the fired body is left as it is in the first light emitting portion or the second light emitting portion. Can be used. For example, even if glass is manufactured from a luminescent material or what processed the single crystal of the luminescent material, the 1st light emitting part or the 2nd light emitting part can be manufactured without using a binder. Moreover, even when a binder is not used, it is also possible to make other components, such as an additive, coexist in a 1st light emitting part or a 2nd light emitting part.

In addition, the second light emitting part may be excited by light emitted from the light source and the first light emitting part, and in addition to a light emitting material, a binder, and other components that emit light containing components having a longer wavelength than light emitted by the first light emitting part, The light emitting materials of one light emitting part may be mixed. However, in order to obtain a larger luminous flux, the concentration of the light emitting material of the first light emitting part contained in the second light emitting part is preferably small, and more preferably the light emitting material of the first light emitting part is not contained in the second light emitting part. .

On the other hand, the first light emitting part usually does not contain the light emitting material of the second light emitting part, but as long as the luminous flux of the light emitted by the first light emitting part does not become small, the light emitting material of the second light emitting part may contain 40 volume. % Or less is preferable and it is more preferable that the luminescent substance of a 2nd light emitting part is not contained at all. That is, even when the light emitting material in the second light emitting part is excited by the light emitted from the first light emitting part, the light emitting material of the second light emitting part does not absorb the light emitted by the light emitting material of the first light emitting part from the first light emitting part too much. In order to avoid this, the light emitting material in each light emitting part should be selected.

[I-2-2. bookbinder]

As described above, the first light emitting part and the second light emitting part may contain a binder in addition to the light emitting material. A binder is normally used in order to mix | blend a powder-like or particle-shaped light emitting material, or to adhere to a frame. There is no restriction | limiting about the binder used for the light emitting device of this invention, A well-known thing can be used arbitrarily.

However, when the light emitting device is configured such that light emitted from the light source, the first light emitting part and the second light emitting part is transmitted through the first light emitting part or the second light emitting part and emitted outside the light emitting device, It is preferable to select what transmits each component of the light emitted by the light emitting device.

For example, in addition to resin, inorganic materials, such as glass, can also be used for a binder. As the specific example, organic resin, such as an epoxy resin and a silicon resin, inorganic materials, such as a polysiloxane gel and glass, etc. are mentioned as resin.

Moreover, when using resin as a binder, although the viscosity of the resin is arbitrary, it is preferable to use the binder which has a suitable viscosity according to the particle size and specific gravity of the luminescent substance to be used, especially the specific gravity per surface area. For example, when using an epoxy resin for a binder, when the particle diameter of a luminescent substance particle is 2 micrometers-5 micrometers, and the specific gravity is 2-5, when an epoxy resin of the viscosity of 1-10 Pas is used normally, a light emitting substance It is preferable because the particles can be dispersed well.

In addition, a binder may be used individually by 1 type, and may use 2 or more types together by arbitrary combinations and a ratio.

[I-2-3. Use ratio of luminescent material]

When the binder is used as the light emitting material, the ratio of the light emitting material to the binder is not limited, but the ratio of the light emitting material to the binder is usually at least 0.01, preferably at least 0.05, more preferably at least 0.1, Moreover, it is preferable that it is 5 or less normally, Preferably it is 1 or less, More preferably, it is 0.5 or less.

However, when the light emitting device is a transmissive type, in order to obtain a higher luminous flux, it is preferable that the light emitting material is suitably dispersed in the first light emitting part and the second light emitting part. On the other hand, when the light emitting device is of a reflective type (that is, light emitted from the light source, the first light emitting part and the second light emitting part is emitted outside the light emitting device without passing through the first light emitting part or the second light emitting part), In order to obtain a higher luminous flux, the light emitting material is preferably filled at a higher density. Therefore, the composition of the light emitting material should be set according to the use of the light emitting device, the kind and physical properties of the light emitting material, the kind or viscosity of the binder, and the like while taking these into consideration.

In addition, the light emission color of the light emitted by the light emitting device can be arbitrarily changed by adjusting the ratio of the light emitting materials of the first light emitting portion and the second light emitting portion, and the use weight of the light emitting material. Accordingly, not only light whose color coordinates are (x = 0.333, y = 0.333), but also (x = 0.47, y = 0.42), (x = 0.35, y = 0.25), (x = 0.25, y = 0.30), Intermediate colors such as (x = 0.30, y = 0.40) are also possible.

[I-2-4. Other ingredients]

In addition, the first light emitting portion and the second light emitting portion may be formed of a light emitting material by containing other components, and a light emitting material, and a binder and other components suitably used.

There is no restriction | limiting in particular in other components, A well-known additive can be used arbitrarily. For example, when controlling the light distribution characteristic and mixed color of a light emitting device, it is preferable to use a diffusing agent, such as alumina and yttria, as another component. For example, when filling a luminescent substance at high density, it is preferable to use binders, such as calcium pyrolate and a barium calcium borate, as other components.

I-2-5. Manufacturing Method of Light Emitting Part]

There is no restriction | limiting in particular in the manufacturing method of a 1st light emitting part and a 2nd light emitting part, It can manufacture by arbitrary methods. Hereinafter, although the manufacturing method of a 1st light emitting part and a 2nd light emitting part is illustrated and demonstrated, it is also possible to manufacture a 1st light emitting part and a 2nd light emitting part by methods other than the manufacturing method demonstrated below.

For example, the first light emitting part and the second light emitting part disperse a light emitting material, a binder and other components suitably used in a dispersion medium to prepare a slurry, apply the prepared slurry to a substrate such as a frame, and then dry the slurry. Can be formed.

The slurry is prepared by mixing a light emitting material with other components such as binders and additives suitably used in a dispersion medium. In addition, although a slurry may change a name into paste, a pellet, etc. according to the kind of binder, in this specification, it is called a slurry including these.

There is no restriction | limiting in the dispersion medium used for slurry preparation, A well-known dispersion medium can be used arbitrarily. Specific examples thereof include chain hydrocarbons such as n-hexane, n-heptane and sorbetho, aromatic hydrocarbons such as toluene and xylene, halogenated hydrocarbons such as trichloroethylene and perchloroethylene, methanol, ethanol, isopropanol, n Alcohols such as butanol, ketones such as acetone, methyl ethyl ketone and methyl isobutyl ketone, esters such as ethyl acetate and n-butyl acetate, ethers such as cellosolve, butylsolve and cellosolve acetate, water and any Aqueous solvents, such as aqueous solution of these, etc. are mentioned.

Next, the prepared slurry is apply | coated to base materials, such as a frame. Although the coating method is arbitrary, methods, such as a dispensing and a potting, can be used, for example.

In addition, when apply | coating a slurry directly to a frame, the order of application | coating of the slurry used as a 1st light emitting part and the slurry used as a 2nd light emitting part is arbitrary, and you may apply | coat any one first. Moreover, you may apply simultaneously.

After application, the dispersion medium is dried to prepare a first light emitting portion and a second light emitting portion. Although a drying method is arbitrary, you may use methods, such as natural drying, heat drying, vacuum drying, baking, and electron beam irradiation, for example. Especially, baking at the temperature of several tens degreeC thru | or several hundreds degreeC is preferable, since it can easily and reliably remove a dispersion medium by inexpensive installation.

As described above, in the case of densification of the light emitting material for the purpose of manufacturing the reflective light emitting device, it is preferable to mix the binder as other components in the slurry. Moreover, when apply | coating the slurry which mixed the binder, it is preferable to use coating methods, such as screen printing type and inkjet printing. This is because the area distribution of the first light emitting part and the second light emitting part is simple. Of course, when using a binder, you may apply | coat by a normal coating method.

Moreover, there also exists a method of manufacturing a 1st light emitting part and a 2nd light emitting part, without using a slurry. For example, a 1st light emitting part and a 2nd light emitting part can also be manufactured by mixing and kneading | molding a luminescent substance, the binder suitably used, and another component. In addition, when shaping | molding, shaping | molding can also be performed by performing press molding, extrusion molding (T-die extrusion, inflation extrusion, blow molding, melt spinning, mold release extrusion etc.), injection molding, etc., for example.

In the case where the binder is thermosetting such as an epoxy resin or a silicon resin, the binder before curing, the light emitting material, and other components suitably used are mixed and molded, and then the binder is cured by heating to give the first light emission. The part and the second light emitting part can be manufactured. Moreover, when a binder is UV curable, binder resin can be hardened | cured by irradiating UV light instead of heating of the said method, and a 1st light emitting part and a 2nd light emitting part can be manufactured.

By the way, although the 1st light emitting part and the 2nd light emitting part may be manufactured in a series of process at the time of manufacture of a light emitting device, the 1st light emitting part and the 2nd light emitting part are prepared separately previously, and it attaches later to a frame etc. to complete a light emitting device. You may do so. Moreover, it is also possible to prepare the unit which combined the frame, any one of a 1st light emitting part, and a 2nd light emitting part, and to combine this unit, and to complete a light emitting device.

Moreover, the method of forming a light shielding part is also arbitrary in this regard. For example, the first light emitting portion and the second light emitting portion may be formed first, and then the light shielding portion may be formed later, and the light shielding portion may be formed in advance in the frame, and the slurry or the like may be applied to the recesses divided by the light shielding portions, respectively. By apply | coating, you may make it form a 1st light emitting part and a 2nd light emitting part later.

I-3. Embodiment]

EMBODIMENT OF THE INVENTION Hereinafter, although this invention is given and embodiment of this invention is described, this invention is not limited to the following embodiment, It can implement arbitrarily modified in the range which does not deviate from the summary of this invention.

[I-3-1. 1st Embodiment]

1A and 1B are diagrams schematically showing the main parts of a light emitting device as a first embodiment of the present invention, in which FIG. 1A is a cross-sectional view thereof, and FIG. 1B is an exploded perspective view showing the partition plate separately for explanation.

1A and 1B, the light emitting device 1 of the present embodiment includes a frame 2, a blue LED (blue light emitting portion; 3) serving as a light source, and a green light emitting portion 4 serving as a first light emitting portion. And a red light emitting part 5 serving as a second light emitting part and a partition plate 6 serving as a light blocking part.

The frame 2 is a resin base for holding the blue LED 3, the green light emitting portion 4, the red light emitting portion 5, and the partition plate 6. In the upper surface of the frame 2, recesses (dents) 2A having a trapezoidal cross section opened upward in the drawing are formed. As a result, since the frame 2 is in the shape of a cup, the light emitted from the light emitting device 1 can be directed and the light emitted can be effectively used. In addition, the dimension of the recessed part 2A of the light emitting device 1 (the slope of the slope, the depth from the opening to the bottom surface, etc.) indicates that the light emitting device 1 emits light in a predetermined direction (here, upward direction in the drawing). It is set to the dimension which can be discharged toward.

In addition, at the bottom of the recessed portion 2A, an electrode (not shown) to which electric power is supplied from the outside of the light emitting device 1 is formed, from which the electric power can be supplied to the blue LED 3.

In addition, the inner surface of the concave portion 2A of the frame 2 has a high reflectance of light in the entire visible region due to the metal plating, and thus, the light intensity that reaches the inner surface of the concave portion 2A of the frame 2, The light emitting device 1 can be discharged in a predetermined direction. It goes without saying that the metal plating does not short the electrode.

At the bottom of the recessed portion 2A of the frame 2, a blue LED 3 is provided as a light source. The blue LED 3 is an LED that emits blue light when electric power is supplied. Part of the blue light emitted from this blue LED 3 is absorbed as excitation light by the light emitting material (here, a fluorescent material) in the green light emitting part 4 and the red light emitting part 5, and another part is a light emitting device. It is emitted from (1) toward a predetermined direction (here, upward direction in a figure).

In addition, as mentioned above, although the blue LED 3 is provided in the bottom part of the recessed part 2A of the frame 2, here, between the frame 2 and the blue LED 3, it is a silver paste (silver to an adhesive agent). It is adhere | attached by the thing which mixed particle | grains: 7, and the blue LED 3 is attached to the frame 2 by this. In addition, this silver paste 7 also plays a role of dissipating heat generated by the blue LED 3.

In addition, the frame 2 is attached with a forbidden wire 8 for supplying electric power to the blue LED 3. That is, the electrode (not shown) formed in the bottom part of the recessed part 2A of the blue LED 3 and the frame 2 is connected by wire bonding using the wire 8, and this wire 8 is connected. By energizing, electric power is supplied to the blue LED 3, and the blue LED 3 emits blue light.

In addition, in the recess 2A of the frame 2, the green light emitting portion 4 as the first light emitting portion and the red light emitting portion 5 as the second light emitting portion are formed.

The recessed portion 2A is filled by the green light emitting portion 4 and the red light emitting portion 5, and the green light emitting portion 4 and the red light emitting portion 5 are formed at the opening of the recessed portion 2A by the light emitting device ( The surface which is in contact with the outside of 1) functions as the light emission surface 1A which the light emitting device 1 emits light toward a predetermined direction. That is, blue light emitted from the blue LED 3, green light emitted from the green light emitting part 4, and red light emitted from the red light emitting part 5 are emitted from the light exit surface 1A toward the predetermined direction. It is supposed to be.

The green light emitting portion 4 is formed of a green phosphor and a transparent resin. The green phosphor is a luminescent material of the green light emitting portion 4, and is a fluorescent substance that is excited by blue light emitted by the blue LED 3 and emits green light that is longer wavelength than blue light. In addition, transparent resin is a binder of the green light emitting part 4, and here, epoxy resin which is a synthetic resin which can transmit visible light over the whole wavelength range is used.

The green light emitting portion 4 is formed so as to fill the portion on the left side in the figure from the bottom of the recessed portion 2A to the opening. The green light emitting portion 4 is formed so as to cover the upper surface of the blue LED 3 and side surfaces other than the right side surface in the figure. In addition, the green light emitting portion 4 has a larger volume than the red light emitting portion 5 in the recessed portion 2A.

Moreover, the green light emitting part 4 has the 1st light emission surface 4A in the opening part of the recessed part 2A. This 1st light emission surface 4A is an upper surface in the figure of the green light-emitting part 4 formed in planar shape, and overlaps with the plane which the upper surface of the frame 2 forms. The first light emitting surface 4A is a surface emitting light emitted from the green light emitting portion 4 in a predetermined direction outside the light emitting device 1, and from the first light emitting surface 4A, a blue LED is emitted. (3) The emitted blue light is also emitted. Moreover, 4 A of 1st light output surfaces are comprised with the 2nd light output surface 5A mentioned later and comprise the light output surface 1A which emits the light which the light emitting device 1 emits to the exterior. As a result, the green light emitting portion 4 remains open at the light exit surface 1A.

On the other hand, the red light emitting portion 5 is formed of a red phosphor and a transparent resin. The red phosphor is a light emitting material of the red light emitting portion 5, which is excited by blue light emitted by the blue LED 3 and green light emitted by the green light emitting portion 4, and emits red light which is longer wavelength than green light. to be. In addition, the transparent resin is a binder of the red light emitting part 5, and here, similarly to the green light emitting part 4, an epoxy resin capable of transmitting visible light is used.

The red light emitting part 5 is formed so as to fill the part of the right side in the figure from the bottom part of the recessed part 2A to the opening part. As described above, the green light emitting portion 4 is also formed over the opening portion at the bottom of the concave portion 2A, and therefore, in the light emitting device 1, the thickness of the green light emitting portion 4 (in the longitudinal direction in the drawing) Distance) and the red light emitting portion 5 are formed to be almost equal in thickness. Moreover, the red light emitting part 5 is formed so that the right side surface may be covered in the figure of the blue LED3. The red light emitting portion 5 occupies a smaller volume than the green light emitting portion 4 in the recessed portion 2A.

In addition, the red light emitting portion 5 also has a second light exit surface 5A in the opening of the recessed portion 2A, similarly to the green light emitting portion 4. This 2nd light exit surface 5A is an upper surface in the figure of the red light-emitting part 5 formed in planar shape, and overlaps with the plane which the upper surface of the frame 2 forms. The second light exit surface 5A is a surface that emits light emitted from the red light emitting part 5 in a predetermined direction outside the light emitting device 1, and is blue from the second light exit surface 5. The blue light emitted by the LED 3 is also emitted. In addition, as described above, the second light exit surface 5A, together with the first light exit surface 4A, constitutes the light exit surface 1A for emitting the light emitted from the light emitting device 1 to the outside. have. As a result, the red light emitting part 5 is opened at the light exit surface 1A.

Moreover, between the green light emitting part 4 and the red light emitting part 5, the partition plate 6 is inserted into the insertion part 2B formed in the frame 2 as a light shielding part in the opening part of the recessed part 2A. Attached. This partition plate 6 is formed as a rectangular parallelepiped resin plate extending in the depth direction of the recessed part 2A over the opening part blue LED vicinity, and extending in the whole in the width direction of the recessed part 2A. It is. In addition, the entire surface of the partition plate 6 is subjected to the same plating treatment as the frame 2, whereby the visible light can be efficiently reflected.

Therefore, most of the light emitted from the green light emitting portion 4 is reflected when it hits the partition plate 6 and is not incident on the red light emitting portion 5. Moreover, most of the light emitted from the red light emitting part 5 is reflected when it touches the partition plate 6, and is not made to inject into the green light emitting part 4. As shown in FIG. However, in the vicinity of the bottom of the recessed part 2A, a very small gap is formed between the bottom of the recessed part 2A and the lower end of the partition plate 6, where the green light emitting part 4 and the red light emitting part are formed. (5) is in contact. That is, in this gap portion where the green light emitting portion 4 and the red light emitting portion 5 are in contact with each other, light can travel between the green light emitting portion and the red light emitting portion 5 very slightly.

The light emitting device 1 of the present embodiment is configured as described above. Therefore, when blue light is emitted from the blue LED 3, part of it is used as the excitation light in the green light emitting portion 4, and green light is emitted from the green light emitting portion 4. In addition, another part of the blue light emitted from the blue LED 3 is used as the excitation light in the red light emitting portion 5 and red light is emitted from the red light emitting portion 5. Further, a small amount of the green light emitted from the green light emitting portion 4 is incident on the red light emitting portion 5 from this gap between the green light emitting portion 4 and the red light emitting portion 5, and is absorbed and excited. To be used as light. The blue light, green light, and red light emitted in this manner are emitted from the light output surface 1A in a predetermined direction, respectively.

By this structure, the light emitting device 1 can exhibit high luminous efficiency and color rendering. That is, a partition plate 6 is formed between the green light emitting portion 4 and the red light emitting portion 5 to prevent the light emitted from the green light emitting portion 4 from entering the red light emitting portion 5. Therefore, the amount of light emitted by the green light emitting portion 4 can be suppressed from being absorbed by the red light emitting portion 5, thereby improving the luminous efficiency and color rendering of the light emitting device 1. Moreover, since the dispersion | variation in the component of the light emitted from the light emitting device 1 can also be suppressed, it is possible to improve the color reproducibility of the light emitting device 1, too.

In addition, in this gap portion where the green light emitting portion 4 and the red light emitting portion 5 are in contact with each other, the green light emitted from the green light emitting portion 4 is incident on the red light emitting portion 5, but since the amount thereof is very small, the light emission efficiency is low. In addition, color rendering is not reduced. Of course, by partitioning the part other than the part where the blue LED 3 and the red light emitting part 5 contact with the partition plate 6, the green light emitted from the green light emitting part 4 does not enter the red light emitting part 5 at all. This makes it possible to more reliably increase the luminous efficiency and color rendering.

In addition, since the surface of the frame 2 and the surface of the partition plate 6 are each capable of efficiently reflecting all visible light, blue light emitted from the blue LED 3 and green light emitted from the green light emitting portion 4. And red light emitted from the red light-emitting part 5 are emitted from the light exit surface 1A without being absorbed by the frame 2 or the partition plate 6, so that the respective light can be effectively used, so that luminous efficiency is achieved. Can increase.

[I-3-2. 2nd Embodiment]

2 (a) and 2 (b) are diagrams schematically showing the main parts of a light emitting device as a second embodiment of the present invention, in which Fig. 2 (a) is a sectional view thereof and Fig. 2 (b) is a perspective view thereof; to be. 2 (a), the green light emitting portion 14 and the red light emitting portion 15 are shown to have a large thickness, but the green light emitting portion 14 and the red light emitting portion 15 are actually visual. It is called a film-shaped part formed so thin that it cannot be confirmed.

As shown in Figs. 2A and 2B, the light emitting device 11 of the present embodiment includes a frame 12, a blue LED (blue light emitting portion) 13 which is a light source, and a green light which is a first light emitting portion. The light emitting part 14, the red light emitting part 15 which is a 2nd light emitting part, the partition wall 16, and the beam 19 are provided.

The frame 12 holds the blue LED 13, the green light emitting portion 14, the red light emitting portion 15, the partition wall 16, and the beam 19, similarly to the frame 2 of the first embodiment. As a base made of a resin for the purpose, a concave portion (dent portion) 12A having a trapezoidal cross section opened upward in the figure is formed on the upper surface thereof. Therefore, similarly to the first embodiment, the light emitted from the light emitting device 11 can be given directivity, and the light emitted can be effectively used.

In addition, the frame 12 emits light in contact with the surface of the frame 12 by the metal plating on the surface of the recessed portion 12A, from the light emitting device 11 in a predetermined direction (here, in the upper direction in the figure). I can do it.

The beam 19 is provided in the upper part of the flame | frame 12 from one upper part of the recessed part 12A to the other. This beam 19 is formed of the material which transmits at least the blue light which the blue LED 13 emits, the green light which the green light emitting part 14 emits, and the red light which the red light emitting part 15 emits. In addition, the beam 19 has an electrode (not shown) at the bottom, and is capable of supplying power to the blue LED 13 through the electrode.

The blue LED 13 is provided in the center part of the lower surface of the beam 19 as a light source. Since this blue LED 13 is the same as the blue LED 3 of 1st Embodiment, and functions similarly, description is abbreviate | omitted here. In addition, the blue LED 13 is fixed to the beam 19 by the silver paste 17, and the electric power is supplied through the electrode by the wire 18. At this time, the silver paste 17 and the wire 18 of the light emitting device 11 are the same as the silver paste 7 and the wire 8 of the first embodiment, respectively.

Moreover, on the frame 12, the green light emitting part 14 as a 1st light emitting part and the red light emitting part 15 as a 2nd light emitting part are each formed in the film shape of the same film thickness, and this green light emitting part The entire inner surface of the recessed portion 12A of the frame 12 is covered by the 14 and the red light emitting portions 15.

In addition, the light emitting device 11 is set so that a predetermined direction of emitting light is in the upper direction in the drawing, and therefore, the surface where the green light emitting portion 14 is not in contact with the frame 12 and the partition wall 16. And the surface where the red light emitting portion 15 is not in contact with the frame 12 and the partition wall 16 function as the light emitting surface 11A for emitting light toward the predetermined direction by the light emitting device 11, The green light emitting portion 14 and the red light emitting portion 15 are open at the light exit surface 11A, respectively. Therefore, blue light emitted from the blue LED 13, green light emitted from the green light emitting part 14, and red light emitted from the red light emitting part 15 are emitted from the light exit surface 11A toward the predetermined direction. It is supposed to be. In addition, the light emitted from the blue LED 13 is not directly emitted in a predetermined direction, but is reflected by the frame 12 and emitted to the outside.

The space from the bottom of the recessed portion 12A of the frame 12 to the bottom surface of the beam 19 includes at least blue light emitted by the blue LED 13, green light emitted by the green light emitting part 14, and a red light emitting part ( 15) It is molded by the material (not shown) which permeate | transmits the red light which emits.

The green light emitting portion 14 is formed by forming the same material as the green light emitting portion 4 of the first embodiment on the bottom face and the inclined surface of the recessed portion 12A of the frame 12. Further, the green light emitting portion 14 is formed from the right end of the surface of the recessed portion 12A to the left side of the drawing (here, to the left of the position corresponding to the left end of the blue LED 13) from the center portion to the center portion. For this reason, the green light emitting part 14 has a large volume compared with the red light emitting part 15.

On the other hand, the red light emitting portion 15 is formed by forming the same material as the red light emitting portion 5 of the first embodiment on the surface of the recessed portion 12A of the frame 12. Moreover, the red light emitting part 15 is formed in the bottom part and inclined surface in which the green light emitting part 14 is not formed on the surface of the recessed part 12A. Since the green light emitting portion 14 is formed from the right end in the drawing of the frame 12 to the right side of the drawing from the center portion, the red light emitting portion 15 is more blue LED (in comparison with the green light emitting portion 14). 13) is formed far away.

Therefore, the blue light emitted from the blue LED 13 enters more toward the green light emitting portion 14 than the red light emitting portion 15.

In the light emitting device 11 of the present embodiment, a partition wall 16 is formed at the boundary between the green light emitting portion 14 and the red light emitting portion 15. The partition wall 16 extends in the depth direction of the recessed portion 12A from the bottom surface of the recessed portion 12A to the vicinity of the blue LED 13, and extends throughout the width direction of the recessed portion 12A. It is adhere | attached to the frame 12 as a board of resin of a rectangular parallelepiped shape. In addition, the entire plating surface of the partition wall 16 is subjected to the same plating treatment as that of the frame 12, whereby the visible light can be efficiently reflected.

Therefore, most of the light emitted from the green light emitting portion 14 is reflected when it touches the partition wall 16 and is not incident on the red light emitting portion 15. In addition, most of the light emitted from the red light emitting portion 15 is reflected when it touches the partition wall 16, so that it is not incident on the green light emitting portion 14. However, in the vicinity of the upper part of the partition wall 16, a very small gap is formed between the bottom face of the recessed part 12A and the lower end of the partition plate 16, and the green light emitting part 14 and the red light emitting part are formed in this gap. There is very little light coming and going between (15).

The light emitting device 11 of this embodiment is comprised as mentioned above. Therefore, when blue light is emitted from the blue LED 13, part of it is used as the excitation light in the green light emitting portion 14, and green light is emitted from the green light emitting portion 14. The other part of the blue light emitted from the blue LED 13 is used as the excitation light in the red light emitting portion 15, and the red light is emitted from the red light emitting portion 15. Further, a small amount of the green light emitted from the green light emitting portion 14 passes through the partition wall 16 upper portion, enters the red light emitting portion 15, is absorbed, and is used as excitation light. The blue light, green light, and red light emitted in this manner are emitted from the light exit surface 11A in a predetermined direction, respectively.

By this structure, the light emitting device 11 can exhibit high luminous efficiency and color rendering. That is, a partition wall 16 is formed between the green light emitting portion 14 and the red light emitting portion 15 to prevent the light emitted from the green light emitting portion 14 from entering the red light emitting portion 15. Therefore, the amount of light emitted by the green light emitting portion 14 can be suppressed by the red light emitting portion 15, thereby improving the luminous efficiency and color rendering of the light emitting device 11. In addition, since variations in the components of light emitted from the light emitting device 11 can be suppressed, it is possible to improve the color reproducibility of the light emitting device 11.

A portion of the green light emitted from the green light emitting portion 14 through the partition wall 16 is incident on the red light emitting portion 15. However, since the amount thereof is very small, the luminous efficiency and color rendering property are not deteriorated. Of course, if the partition wall 16 is formed high so that the green light emitted from the green light emitting portion 14 does not enter the red light emitting portion 15 at all, it is possible to more reliably increase the luminous efficiency and color rendering property.

In addition, since the surface of the frame 12 and the surface of the partition wall 16 are each capable of reflecting all visible light, the blue light emitted from the blue LED 13, the green light emitted from the green light emitting portion 14, and the red color are red. Since the red light emitted from the light emitting portion 15 is not absorbed by the frame 12 or the partition wall 16 and is emitted from the light exit surface 11A, each light can be used effectively, thereby improving the light emission efficiency. have.

Moreover, according to the light emitting device 11, the effect | action and effect similar to the light emitting device 1 of 1st Embodiment can be exhibited.

[I-4. Use of Light Emitting Device]

There is no restriction | limiting in the use of the light emitting device of this invention, It is applicable to the arbitrary use which uses light. Specific examples of the use include illumination, a backlight unit for a display device, a display device (display) and the like.

There is no restriction | limiting in particular when using the light-emitting device of this invention as illumination, For example, it can be used in various aspects as illumination, such as a camera flash, the light of a video camera, the lighting fixture of indoor and outdoor. The light emitting device of the present invention also has a different wavelength (i.e. color) of light emitted from each of the first light emitting part and the second light emitting part, but the light emitted from the light emitting device is sufficiently spread after being emitted from the light emitting device, Since the light emitted from the first light emitting portion and the second light emitting portion is sufficiently visible, the eyes are visible, and when observed by time, the light is not separated for each component but is displayed as the target color. When the light emitting device of the present invention is used as illumination, it becomes possible to irradiate high color rendering light with high luminous efficiency.

Moreover, the light emitting device of this invention can be used as a backlight unit, for example by combining with optical members, such as a light guide plate. For example, although the display backlight unit is attached to the display of a mobile telephone, etc. in order to illuminate the liquid crystal display part from the back side, the light-emitting device of this invention can be used for this display backlight unit.

FIG. 3 is a diagram schematically showing a cross section of the main portion of the display 21 of the cellular phone in order to explain an example of a backlight unit using the light emitting device of the present invention. 3, the light guide plate 23 of the magnitude | size corresponding to the whole back surface of the liquid crystal display part 22 is attached to the back surface of the liquid crystal display part 22. As shown in FIG. This light guide plate 23 is formed as a flat optical member formed of a transparent material which transmits all the light in the visible region, and a light emitting device 24 is mounted on the side thereof. The light emitting device 24 is mounted so that the emitted light can be incident on the light guide plate 23, and the light guide plate 23 and the light emitting device 24 constitute the display backlight unit 25. Therefore, the light emitted by the light emitting device 24 is incident on the light guide plate 23 and is emitted toward the liquid crystal display from the surface facing the liquid crystal display 22 of the light guide plate 23. This makes it possible to brighten the liquid crystal display 22. At this time, although the wavelengths (ie, colors) of the light emitted from each of the first light emitting part and the second light emitting part of the light emitting device 24 are different, the light emitted from the light emitting device 24 is mixed with each other in the light guide plate 23. Since it becomes uniform, there is no possibility that color unevenness etc. may arise when illuminating the liquid crystal display part 22. FIG.

Moreover, when using the light emitting device of this invention for a comparatively large display device (display), etc., the light emitting device of this invention may be used as a backlight which directly illuminates a liquid crystal display part from a back surface. Even in such a case, since the light emitted from the light emitting device is mixed with each other and uniform until it reaches the liquid crystal display, color unevenness does not occur.

In addition, in order to diffuse the light emitted by the light emitting device using a diffusion plate, a light diffusing layer, or the like in order to mix the respective components of the light emitted by the light emitting device, the light can be uniformed more reliably. Such a method is preferable for use in applications where it is desirable to leave no slight unevenness of the emission color, for example, an indicator of an audio device.

In this way, when the light emitting device of the present invention is used as a backlight or a backlight unit of a display device, it becomes possible to provide a display having good color reproducibility and high luminous efficiency (luminance).

[II. Description of display device]

Next, the display apparatus of this invention is demonstrated in detail, showing 3rd embodiment of this invention. However, although 3rd Embodiment of this invention is described using the following drawings, this invention is not limited to the following 3rd Embodiment, It can carry out by changing arbitrarily in the range which does not deviate from the summary of this invention. Can be.

4 to 6 are for explaining the third embodiment of the present invention, FIG. 4 is a schematic exploded perspective view for explaining the outline of the display device, FIG. 5 is a schematic plan view of the backlight unit, and FIG. 6 is a backlight. It is typical sectional drawing for demonstrating the principal part of a unit.

The display device of this embodiment includes a backlight unit and an image forming unit. Moreover, the display apparatus of this embodiment is comprised suitably including other structural members, such as a diffuser plate and a light guide plate.

4 is a schematic exploded perspective view showing a display device of the present embodiment. As shown in FIG. 4, the display device of the present embodiment includes a backlight unit 101, a diffusion plate 102, and an image forming unit 103.

[II-1. Backlight unit]

The backlight unit 101 is a member that emits white light as a backlight toward the image forming unit 103 through the diffusion plate 102. Note that the light emitted from the backlight unit 101 is not only diffused from the backlight unit 101 by the backlight unit 101 when the light is emitted from the backlight unit 101. Light which is not white is diffused until it reaches the image forming unit 103, and it is assumed that it is pointed broadly even when it becomes white at the point of time when the image forming unit 103 is reached.

5 is a schematic plan view of the backlight unit 101 used in the display device of the present embodiment. As shown in FIG. 5, in the present embodiment, the backlight unit 101 includes a plurality of light emitting units 105 (here, seven) for emitting white light on the substrate 104 as a frame. Moreover, each light emitting part 105 is provided with the green light emitting part 106 as a 1st light emitting part, and the red light emitting part 107 as a 2nd light emitting part.

[II-1-1. Board]

The board | substrate 104 is a base for forming the light emitting part 105, and can be comprised similarly to the frame in the above-mentioned light emitting device. Therefore, the shape, the dimension, and the like can be arbitrarily set according to the shape, the dimension, the use, and the like of the display device. For example, a plate shape, a cup shape, etc. are mentioned as a shape of the light emitting part 105 of the board | substrate 104. FIG. Moreover, about the surface, it is preferable to set it as a suitable shape according to the use, such as a flat surface, a curved surface, an uneven surface.

Moreover, although it is arbitrary also about the material of the board | substrate 104, it is preferable to form with the material which does not transmit at least green light normally. It is also possible to use a material that transmits green light as the material of the substrate 104, but in that case, a process of preventing the transmission of green light, such as coating the surface of the substrate 104 with a material that does not transmit at least green light, It is preferable to carry out. The point of preventing the transmission of green light is described in detail in the description of the light emitting section 105.

As a specific example of the board | substrate 104, the thing similar to the frame in the above-mentioned light emitting device is mentioned. Especially, as an inorganic material, ceramics, glass epoxy resin etc. are preferable as an organic material. In addition, the material of the board | substrate 104 may be used individually by 1 type, and may use 2 or more types together by arbitrary combinations and a ratio.

In addition, it is preferable to use a material having good heat dissipation for the material of the substrate 104. For example, it is preferable to use a material with high thermal conductivity. A light source (see blue light source 108 in FIG. 6) and the like in the light emitting portion 105 heat during use, but when the substrate 104 is formed with good heat dissipation, it is used continuously stably even when heat is generated during use. Because it is possible to do.

In addition, it is preferable to use an insulating material for the material of the substrate 104.

However, when constituting the display device, it is preferable to pay attention to the color when selecting the material of the substrate 104. Although the color is arbitrary for the board | substrate 104, it is usually preferable to use the thing of a white or silver material. This is for the following reason. That is, light reflected by the diffuser plate 102 or the image forming unit 103 by a portion of the white light emitted from the light emitting portion 105 or light incident from the outside of the display device is the image forming apparatus of the backlight unit 101. The white light may be reflected toward (103) (hereinafter referred to as "white light emitting surface" as appropriate), and may be reflected, and the reflected light may illuminate the image forming unit 103 from the back surface. At this time, if there is absorption of visible light in the substrate 104, there is a possibility that a decrease in luminous efficiency or color irregularity may occur. Therefore, it is preferable that at least the site | part which becomes the white light emission surface of the board | substrate 104 is white or silver. Therefore, the white light emitting surface of the substrate 104 is preferably formed of a white or silver material.

In addition, the portion of the surface of the substrate 104 facing the green light emitting portion 106 or the red light emitting portion 107 in the light emitting portion 105 has a high reflectance of at least one of the components of the light reaching the portion. It is preferable that it is especially preferable that the reflectance of the light of visible light whole is high. Thereby, the luminous efficiency of the backlight unit 101 can be improved more. Therefore, it is preferable that the site | part which said light hits is formed of the material with high reflectance. As an example of the method of improving a reflectance, the same thing as the above-mentioned light-emitting device is mentioned, for example.

In general, an electrode or wiring for supplying electric power to the light source is formed in the substrate 104. Although the electrode and the wiring may be formed in any way, in the case of constituting the display device, it is preferable to form a wiring pattern on the back surface of the substrate 104 by using a through hole, which is easy to manufacture. In addition, the material of an electrode and wiring is also arbitrary, For example, Cu, Au plated Cu, Ag plated Cu, Al, Ag, etc. can be used.

In the present embodiment, the substrate 104 is formed as a white plate-shaped substrate 104, and the surfaces of the green light emitting portion 106 and the red light emitting portion 107 reflect light of the wavelength of the entire visible region. It is supposed that the surface treatment is performed so that it may be. In addition, the substrate 104 has a wiring 109 for supplying electric power to the blue light source 108 on the rear surface thereof, and the electrode 110 is provided at a position corresponding to each of the light emitting portions 105. (See FIG. 6).

[II-1-2. Blue light source]

6 is a schematic cross-sectional view of the light emitting portion 105. As shown in FIG. 6, the light emitting part 105 is equipped with the green light emitting part 106 which is a 1st light emitting part, and the red light emitting part 107 which is a 2nd light emitting part. In addition, the blue light source 108 is formed in the green light emitting unit 106 and the red light emitting unit 107, respectively.

The blue light source 108 emits excitation light of the luminescent material contained in the green light emitting unit 106 and the red light emitting unit 107 in the same manner as the light source in the light emitting device described above. It emits light and is a light source for emitting blue light as one component of the white light emitted by the backlight unit 101. That is, some of the blue light emitted from the blue light source 108 is absorbed as excitation light by the light emitting materials in the green light emitting unit 106 and the red light emitting unit 107, and another part is formed by the backlight unit 101. It is intended to be released toward the unit 103.

Although the kind of blue light source 108 is arbitrary, a suitable thing can be selected according to the use and a structure of a display apparatus, Usually, it is preferable to use the thing which does not have a bias in light distribution and diffuses the light emitted widely. .

Examples of the blue light source 108 include the same ones as those exemplified in the description of the light emitting device, and usually, inexpensive LEDs are preferable.

In addition, when using LED as the blue light source 108 in this way, although there is no restriction | limiting in the shape, In order to improve the light extraction efficiency, it is preferable to make the side surface into a taper shape.

Moreover, the material of the package of LED is also arbitrary, For example, ceramics, PPA (poly phthalamide), etc. can be used suitably. However, similarly to the substrate 104 described above, the color of the package is preferably white or silver from the viewpoint of improving the color reproducibility of the display device, and from the viewpoint of increasing the luminous efficiency of the backlight unit 101, the reflectance of light is It is desirable to be elevated. In addition, when there is wiring for the blue light source 108, the color and reflectance of the wiring are also the same as those of the substrate 104 or the LED package.

Moreover, when attaching the blue light source 108 to the board | substrate 104, although the specific method is arbitrary, it can attach, for example using solder. Although the kind of solder is arbitrary, the same thing as what was illustrated by description of the light-emitting device is mentioned, for example. In particular, when a large current type LED, a laser diode, or the like, in which heat dissipation is important, is used as the blue light source 108, since the solder exhibits excellent heat dissipation, it is effective to use the solder for installation of the blue light source 108.

Moreover, also when attaching the blue light source 108 to the board | substrate 104 by means other than solder | pewter, the same thing as what was illustrated by description of the light-emitting device is mentioned, for example. By using a conductive paste such as carbon particles mixed in a paste shape, it is possible to supply electric power to the blue light source 108 by energizing the adhesive as in the case of using solder. Moreover, when these conductive fillers are mixed, since heat dissipation also improves, it is preferable.

In addition, the electric power supply method with respect to the blue light source 108 is also arbitrary, For example, the same thing as what was illustrated by description of the light emitting device is mentioned.

In addition, the blue light source 108 may be used individually by 1 type, and may use 2 or more light sources together. In addition, the blue light source 108 may be used only by 1 type, and may use 2 or more types together.

In addition, although the blue light source 108 may share one blue light source 108 in the green light emission part 106 and the red light emission part 107, or may share in two or more light emission parts 105, Usually, In order to enhance the color rendering of the white light emitted from the backlight unit 101, it is preferable to form a blue light source 108 in each of the green light emitting unit 106 and the red light emitting unit 107.

The wavelength of the blue light emitted by the blue light source 108 is arbitrary as long as the backlight unit 101 can emit light having a desired wavelength (in this embodiment, white light), but is usually 350 nm or more, preferably 370 nm or more, more preferably 380 nm or more, even more preferably 400 nm or more, particularly preferably 430 nm or more, and usually 600 nm or less, preferably 570 nm or less, more preferably 550 nm or less, More preferably, it is preferable to absorb light of 500 nm or less, particularly preferably 480 nm or less.

Among these, the wavelength of blue light emitted by the blue light source 108 used in the green light emitting unit 106 is usually 350 nm or more, preferably 400 nm or more, more preferably 430 nm or more, and usually 520 nm. Hereinafter, Preferably it is 500 nm or less, More preferably, it is 480 nm or less.

On the other hand, the wavelength of the blue light emitted by the blue light source 108 used in the red light emitting unit 107 is usually 400 nm or more, preferably 450 nm or more, more preferably 500 nm or more, and usually 600 nm or less. Preferably, it absorbs light of 570 nm or less, More preferably, 550 nm or less.

In the present embodiment, as the blue light source 108, an LED emitting blue light is used for each of the green light emitting unit 106 and the red light emitting unit 107. Moreover, as shown in FIG. 6, the board | substrate 104 is equipped with the wiring 109 formed in the back surface, and the electrode 110 which connects each blue light source 108 and the wiring 109, and this wiring It is assumed that power can be supplied to the blue light source 108 by the 109 and the electrode 110.

[II-1-3. Green light emitting part and red light emitting part]

The green light emitting unit 106, which is the first light emitting unit, is excited by blue light emitted by the blue light source 108, and emits green light containing a component of a green light emitting region having a longer wavelength than the blue light. Green light-emitting body).

Typically, the green light emitting portion 106 is formed as a filling portion (concave portion) formed in the substrate 104 filled with the above light emitting material. Therefore, the shape of the green light emitting portion 106 is formed in a shape corresponding to the shape of the charging portion. Although there is no restriction | limiting in particular in the shape of the green light emitting part 106, Usually, when it is set as cup shape as shown in FIG. 6, for example, it can make directivity to the light emission direction, and light emission of the backlight unit 101 is performed. It is preferable because the efficiency can be increased.

In addition, the green light emitting part 106 may be formed independently at one point, may be divided into two or more points, and may be formed in the same number with respect to the number of the red light emitting parts 107, and may differ from each other. You may form as many as a number.

In the green light emitting unit 106, the blue light emitted from the blue light source 108 is received, whereby the light emitting material emits light using the received blue light as the excitation light. The emitted light (green light) is emitted toward the image forming unit 103 as one component of the white light emitted by the backlight unit 101.

On the other hand, the red light emitting portion 107 as the second light emitting portion is excited by the blue light emitted by the blue light source 108, and at least one kind capable of emitting red light containing a component of the red light emitting region having a longer wavelength than the blue light and the green light. It is formed by containing a light emitting substance (red light emitting body).

Normally, similarly to the green light emitting portion 106, the red light emitting portion 107 is also formed as the filling portion (concave portion) formed in the substrate 104 filled with the above light emitting material. Therefore, the shape of the red light emitting portion 107 is also formed in the shape corresponding to the shape of the charging portion. Although there is no restriction | limiting in particular also in the shape of the red light emitting part 107, Usually, it is preferable to set it as cup shape similarly to the green light emitting part 106. FIG.

In addition, the red light emitting portion 107 may be formed alone at one point, may be divided into two or more positions, and may be formed in the same number as the number of the green light emitting portions 106. You may form as many different numbers.

In the red light emitting unit 107, the blue light emitted from the blue light source 108 is received, whereby the light emitting material emits light using the received blue light as the excitation light. The emitted light (red light) is emitted toward the image forming unit 103 as one component of the white light emitted by the backlight unit 101.

However, in the present embodiment, the green light emitting portion 106 and the red light emitting portion 107 are each formed at least in part, preferably all of them independently. That is, by forming the green light emitting part 106 and the red light emitting part 107 separately, at least a part, preferably all of the green light emitted from the green light emitting part 106 enters the red light emitting part 107. It is formed so as not to. Normally, the green light emitted from the green light emitting unit 106 is such that the white light emitted from the backlight unit 101 toward the image forming unit 103 can exhibit a high luminous efficiency and color reproducibility high enough to withstand practical use. What is necessary is just to be able to prevent that it injects into this red light emission part 107. In addition, it is preferable to prevent all of the green light emitted from the green light emitting portion 106 from entering the red light emitting portion 107. Accordingly, since the green light emitted from the green light emitting portion 106 can be prevented from being consumed as excitation light of the light emitting material in the red light emitting portion 107, the decrease in the intensity of the green light emitted by the green light emitting portion 106 is prevented. The light emission efficiency of the backlight unit 101 can be increased. In addition, since green light is absorbed as excitation light, the intensity of red light emitted from the red light emitting portion 107 can be prevented from being excessively increased, so that the color rendering property of the white light emitted from the backlight unit 101 can be improved. There is also an advantage.

Since the green light emitting part 106 and the red light emitting part 107 are usually formed by filling each light emitting material in the charging section formed in the substrate 104, the green light emitting part 106 is formed by the substrate 104. The sweating green light is shielded from being incident on the red light emitting portion 107. That is, the portion between the green light emitting portion 106 and the red light emitting portion 107 of the substrate 104 functions as the light shielding portion described above in the description of the light emitting device. Of course, for this purpose, the material of the substrate 104 is made of a material capable of shielding at least green light as described above, or coating the surface thereof.

In particular, when not only the transmission of green light is prevented, but also formed so as to reflect at least one, preferably all, of blue light, green light and red light, the above-mentioned blue light, green light, red light, etc. can be effectively used, and the backlight The luminous efficiency of the unit 101 can be further improved.

In order to more reliably prevent the transmission of green light, a wall portion that prevents the transmission of green light may be provided between the green light emitting part 106 and the red light emitting part 107. For example, when a portion between the green light emitting portion 106 and the red light emitting portion 107 of the white light emitting surface of the substrate 104 is formed convexly, the convex portion is formed as the wall portion to more reliably transmit green light. It can prevent. At this time, the shape, dimensions, and the like of the wall portion are arbitrary. Moreover, the material of a wall part is arbitrary, and the same thing as the board | substrate 104 can be used. In addition, it is the same as that of the board | substrate 104 that it is preferable to make the reflectance of the surface of a wall part high. In this case, this wall portion also functions as the light shielding portion described above.

As described above, in order to prevent the green light emitted by the green light emitting unit 106 from entering the red light emitting unit 107, both the green light emitting unit 106 and the red light emitting unit 107 are external to the white light emitting surface. It is preferable that it is opened. That is, the green light emitted from the green light emitting portion 106 is emitted toward the image forming unit 103 from the white light emitting surface without passing through the red light emitting portion 107, and the red light emitted from the red light emitting portion 107 It is preferable to be emitted toward the image forming unit 103 from the white light emitting surface without passing through the green light emitting portion 106. In addition, a protective layer is formed on the white light emitting surface or a cover is attached to the backlight unit 101 so that green light and red light are emitted to the outside of the backlight unit 101 through other members such as a protective layer or a cover. Even in this case, it is assumed that the green light emitting portion 106 and the red light emitting portion 107 are open as long as other members such as a protective layer or a cover can transmit green light and red light.

When the green light emitting portion 106 and the red light emitting portion 107 are opened on the white light emitting surface as described above, the green light and the red light are respectively absorbed by other light emitting materials or shielded by other members to the extent that the strength is weakened. Can be made smaller (or eliminated). Therefore, the luminous efficiency of the backlight unit 101 can be improved. In addition, variations in the components of the white light emitted from the backlight unit 101 can be reduced, and color rendering properties can be enhanced. In addition, since the white light can be reliably emitted using three primary colors of blue light, green light, and red light, the display device is appropriately selected by selecting the blue light source 108, the green light emitting part 106, and the red light emitting part 107. It is also possible to improve the color reproducibility of the.

The structure capable of increasing the luminous efficiency of the backlight unit 101 is basically the same as in the case of the light emitting device, but pays particular attention to its use as a display device, and in contrast to the prior art, the backlight is again The structure which can raise the luminous efficiency of the unit 101 is demonstrated in detail.

Conventionally, when white light is synthesized without using all of blue light, green light and red light at the same time, color reproducibility is not sufficient. In addition, even when both blue light, green light, and red light are used simultaneously, the light emitting material 105 emitting green light and the light emitting material emitting red light are used without dividing the light emitting part 105 into the green light emitting part 106 and the red light emitting part 107. When white light was synthesized, part of the green light was absorbed and consumed by the light emitting material emitting red color. This is true even when the light emitting material emitting green light and the light emitting material emitting red light are mixed and dispersed in the same light emitting part, and when the light emitting material emitting green light and the light emitting material emitting red light are divided into other light emitting parts as in Patent Document 1, respectively. Same. For this reason, the intensity | strength of the green light which will be emitted outside the backlight unit 101 fell, the luminous flux of the white light emitted from the backlight unit 101 decreased, and luminous efficiency was falling. In addition, the green light is absorbed by the luminescent material emitting red light, and the red light becomes stronger, so that the balance of the components of the white light emitted from the backlight unit 101 is disturbed, thereby degrading the color reproducibility of the display device.

In addition, when the white light emitted from the backlight unit 101 is intended to be the desired white, conventionally, in order to supplement the light from the green light emitting portion absorbed by the red light emitting portion, the green light emitting portion is used with respect to the light emitting material emitting red light. It was necessary to increase the ratio of the luminescent material. However, since the color rendering property of the white light is determined by the kind and the use ratio of the light emitting material to be used, in the conventional backlight unit such as Patent Document 1, the use ratio of the light emitting material tends to deviate greatly from the optimum value. It was easy to fall also.

On the other hand, in the backlight unit 101 used in the present embodiment, since green light can be prevented from entering the red light emitting portion 107, the green light is absorbed by the red light emitting portion 107, and the intensity thereof is weak. It can suppress deterioration. Therefore, the luminous efficiency of the backlight unit 101 can be improved than before.

In addition, since the red light emitting unit 107 can suppress the absorption of green light and emit light, the deviation of the components of the white light emitted from the backlight unit 101 can be reduced to increase the color rendering property of the backlight unit 101. . As a result, the color rendering and color reproducibility of the display device can be improved.

By the way, if the light (blue light, green light and red light) emitted from the blue light source 108, the green light emitting part 106 and the red light emitting part 107 can be emitted from the backlight unit 101, the green light emitting part 106 And the red light emitting part 107 are arbitrary, but the green light emitting part 106 and the red light emitting part 107 are combined so as to emit the desired white light, and the light emitting part 105 is like the present embodiment. It is preferable to install as. That is, since the white light is determined by the ratio of the color and intensity of each of the blue light, the green light, and the red light, the green light emitting part 106 and the red light emitting part 107 from which the white light of the desired color is emitted are as small as possible. When the light emitting portion 105 is configured as a unit unit by combining only a number, and the intensity of the white light is to be increased, the design is made by increasing the number of the light emitting portions 105 which are the unit units. Do. In addition, in this embodiment, although one green light emitting part 106 and one red light emitting part 107 were formed in each one light emitting part 105, the number is arbitrary, and even if it forms 2 or more suitably each, do.

Moreover, the arrangement | positioning at the time of arrange | positioning the green light emitting part 106 and the red light emitting part 107 to the light emitting part 105 is also arbitrary, may arrange | position horizontally like this embodiment, or may be comprised so that one may surround the other. You may arrange in a more complicated shape.

In addition, when increasing the number of light emitting parts 105, arrangement | positioning of each light emitting part 105 is also arbitrary. However, since the image forming unit 103 can be uniformly lightened by the distance between each light emitting part 105 evenly, as shown in FIG. 5, each light emitting part 105 is a figure in which an equilateral triangle is continuous. It is preferable to arrange | position so that it may be located in the vertex of each triangle of (refer the broken line of FIG. 5).

Moreover, although the dimension of the green light emitting part 106 and the red light emitting part 107 is arbitrary, it is usually set according to the target white light. White light is emitted from the backlight unit 101 to the image forming unit 103 as the light obtained by combining blue light, green light and red light as described above. Therefore, the apparent color of the white light also changes in accordance with the intensity of each of the blue light, green light and red light to be synthesized. For this reason, in order to manufacture the white light of the target color, the balance of intensity of each of blue light, green light, and red light is adjusted. At this time, as one method of adjusting the balance of the intensity of each of the blue light, the green light, and the red light, there is a method of adjusting the dimensions of the green light emitting part 106 and the red light emitting part 107. That is, when the green light 106 is to be strengthened, the green light emitting part 106 is made relatively large with respect to the red light emitting part 107, and when the green light is desired to be weak, the green light emitting part 106 is compared with the red light emitting part 107. ) Can be made relatively small.

In addition, the method of adjusting the balance of the intensity | strength of each of blue light, green light, and red light is not limited to the method of adjusting the dimension of the said green light emission part 106 and the red light emission part 107, and arbitrary methods are employ | adopted. can do.

For example, the ratio of the electric current value of the electric power supplied to the blue light source 108 formed in the green light emitting part 106, and the electric current value of the electric power supplied to the blue light source 108 formed in the red light emitting part 107 are adjusted. In this way, the balance of the intensities of the blue light, the green light, and the red light may be adjusted to emit the desired white light.

Further, for example, the blue light source 108 may be pulse driven and adjusted by the duty ratio. That is, the ratio of the pulse lighting time of the blue light source 108 formed in the green light emitting part 106 and the pulse lighting time of the blue light source 108 formed in the red light emitting part 107 are adjusted, whereby blue light, green light, and red light are adjusted. The balance of the respective intensities may be adjusted so that the desired white light can be emitted.

In addition, the ratio of the amount of the luminescent material contained in each of the green light emitting unit 106 and the red light emitting unit 107 is adjusted, and the balance of the intensity of each of the blue light, the green light and the red light is adjusted to thereby emit the desired white light. You can do it.

By the way, when adjusting the balance of the color and intensity of each of the blue light, the green light, and the red light so as to emit the desired white light as described above, the light emitted from the green light emitting part 106 and the red light emitting part 107 are actually used. Adjust the light emitted from That is, the white light generated by synthesizing blue light, green light and red light is, for example, light (hereinafter referred to as "short wavelength light" suitably) synthesized with blue light and green light, and light synthesized blue light and red light (hereinafter, appropriately referred to as " Long wavelength light ”, the short wavelength light is light emitted from the green light emitting part, and the long wavelength light is light emitted from the red light emitting part. Therefore, in order to adjust the color of the white light emitted from each light emitting section 105, the green light emitting section 106 and the red light emitting section 107 are controlled to control the green light emitting section 106 and the red light emitting section 107, respectively. The color and intensity of the short wavelength light and the long wavelength light emitted may be adjusted.

At this time, the short wavelength light (that is, light which synthesize | combined blue light and green light) has the chromaticity coordinates (x, y) normally (0.25, 0.65), (0.43, 0.52) as shown in FIG. And the area surrounded by (0.32, 0.33) and (0.18, 0.33) (area I in FIG. 7), preferably (0.27, 0.53), (0.34, 0.49), (0.27, 0.34) and (0.22, 0.35 ) Is preferably within the area (area II in FIG. 7) surrounded by). This is because the balance between luminance and color reproducibility becomes good.

In addition, the chromaticity coordinates may be determined so that the long-wavelength light (the light obtained by combining blue light and red light) becomes the opposite coordinate with respect to the chromaticity coordinates of the short-wavelength light on the basis of the chromaticity coordinates of the target white light.

In addition, in the present embodiment, the light emitting portion 105 is arranged on the surface of the substrate 104 in the same shape (circular in shape, trapezoidal in cross section), one by one, and separately formed in the charging portion in which the green light emitting portion 106 is formed. ) And the red light emitting portion 107 are filled with a light emitting material and a binder corresponding to the light emitting material. Moreover, as shown in FIG. 6, each light emitting part 105 is arrange | positioned so that each light emitting part 105 may be located in the apex of each triangle of the figure (see the broken line of FIG. 6) in which an equilateral triangle is continuous, It is assumed that the distance between each light emitting portion 105 is equalized.

[II-1-4. Composition of Light Emitting Part]

The green light emitting unit 106, which is the first light emitting unit, has a light emitting material that absorbs excitation light and emits green light. Further, the red light emitting portion 107 as the second light emitting portion has a light emitting material that absorbs excitation light and emits red light. In the green light emitting portion 106 and the red light emitting portion 107, each light emitting material is usually held on the substrate 104 by a binder.

[II-1-4-1. Luminescent material]

The luminescent material can use a well-known thing suitably selected. The light emission itself is not limited even if the light emission is performed by any mechanism such as fluorescence or phosphorescence. In addition, in each of the green light emitting part 106 and the red light emitting part 107, one type of light emitting material may be used alone, or two or more types may be used in any combination and ratio. However, it is preferable that the luminescent material used for each of the green light emitting part 106 and the red light emitting part 107 is selected in accordance with the chromaticity coordinates of the target white light.

In addition, the wavelength of the green light emitted by the light emitting material absorbing the excitation light and emitting green light used for the green light emitting part 106 is arbitrary as long as the backlight unit 101 can emit white light. The wavelength range similar to the preferable emission wavelength range of the luminescent material used for a 1st light emitting part mentioned in description of a light emitting device is mentioned.

On the other hand, the wavelength of the red light emitted by the light emitting material that absorbs excitation light and emits red light used for the red light emitting part 107 is also arbitrary as long as the backlight unit 101 can emit white light. The wavelength range similar to the preferable emission wavelength range of the light emitting substance used for a 2nd light emitting part mentioned in the description of a light emitting device is mentioned.

In addition, the light emitting material has a light emission efficiency of 40% or more, preferably 45% or more, more preferably 50% or more, even more preferably 55% or more, and most preferably 60% or more. It is desirable to. The luminous efficiency shown here is a value expressed as a product of quantum absorption efficiency and internal quantum efficiency.

As a light emitting material of the green light emitting part 106, the same thing as what was mentioned as an example of a thing preferable to the light emitting material of a 1st light emitting part as description of the said light emitting device is mentioned as an example of a preferable light emitting material. On the other hand, as the light emitting material of the red light emitting portion 107, the same as those mentioned as an example of the preferable one for the light emitting material of the second light emitting portion in the description of the light emitting device.

Also in the case of constituting the display device, the light emitting material emits green light or emits red light, and is usually used in the form of particles. At this time, the particle diameter of the light emitting material particles is arbitrary, but is usually 150 µm or less, preferably 50 µm or less, more preferably 20 µm or less, and still more preferably 15 µm or less. If it exceeds this range, the color variation of the white light emitted by the backlight unit 101 increases, and when the luminescent material and the sealing material (binder) are mixed, there is a possibility that it is difficult to apply the luminescent material uniformly. . Moreover, it is 0.001 micrometer or more normally, Preferably it is 0.01 micrometer or more, More preferably, it is 0.1 micrometer or more, More preferably, it is 1 micrometer or more, Especially preferably, it is 2 micrometers or more, Most preferably, it is 5 micrometers or more. If it is less than this range, there exists a possibility that luminous efficiency may fall.

In addition, when forming the green light emitting part 106 and the red light emitting part 107 without using a binder, it is formed similarly to the 1st light emitting part and the 2nd light emitting part in the above-mentioned light emitting device, for example. can do.

In addition, in addition to the light emitting substance which emits red light, a binder, and other components, the red light emitting part 107 may mix the light emitting substance which emits green light. However, in order to obtain a larger luminous flux, it is preferable that the concentration of the light emitting material emitting green light contained in the red light emitting part 107 is small, and that the light emitting material emitting green light is not contained in the red light emitting part 107. More preferred.

On the other hand, although the green light emitting part 106 does not contain the light emitting material which emits red light normally, as long as the luminous flux of green light does not become small, the light emitting material which emits red light may be contained. In that case, the ratio of the light emitting material emitting red light contained in the green light emitting part 106 is preferably 40 vol% or less, and the green light emitting part 106 does not contain any light emitting material emitting red light at all. More preferred.

That is, even if a light emitting material emitting red light is excited by green light, the green light emitting part 106 may not be excessively absorbed by the light emitting material emitting red light from the green light emitted by the green light emitting part 106. The light emitting materials in the light emitting portion 106 and the red light emitting portion 107 must be adjusted respectively.

[II-1-4-2. bookbinder]

As described above, the green light emitting portion 106 and the red light emitting portion 107 may contain a binder in addition to the light emitting material. As in the case of the above-described light emitting device, the binder is usually used to combine the light emitting materials in the form of powder or particles, or to adhere the substrate 104 to the substrate 104. There is no restriction | limiting about the binder used for the backlight unit 101, A well-known thing can be used arbitrarily.

However, the light emitted from the blue light source 108, the green light emitting unit 106 and the red light emitting unit 107 is transmitted through the green light emitting unit 106 as shown in FIG. 6. Alternatively, when the light emitting unit 107 is configured to pass through the red light emitting unit 107 and to be emitted outside the backlight unit 101, each component of the white light emitted from the backlight unit 101 (that is, blue light, green light, and red light) may be used as the binder. It is preferable to choose what is permeable.

Examples of the binder include the same ones as the above-described light emitting device.

Moreover, when using resin as a binder, although the viscosity of this resin is arbitrary, it is preferable to use the binder which has a suitable viscosity according to the particle size and specific gravity of the light emitting material to be used, especially the specific gravity per surface area. For example, as in the case of the light emitting device described above, when the epoxy resin is used in the binder, when the particle diameter of the light emitting material particles is 2 µm to 5 µm and the specific gravity is 2 to 5, usually 1 to 10 Pas. The use of a viscous epoxy resin is preferred because it can disperse the luminescent material particles well.

In addition, a binder may be used individually by 1 type, and may use 2 or more types together by arbitrary combinations and a ratio.

[II-1-4-3. Use ratio of luminescent material]

When the binder is used for the green light emitting portion 106 or the red light emitting portion 107, the ratio of the light emitting material to the binder is not limited, but the ratio of the light emitting material to the binder is usually 0.01 or more, preferably in weight ratio. Is 0.05 or more, more preferably 0.1 or more, and usually 5 or less, preferably 1 or less, and more preferably 0.5 or less.

However, when the backlight unit 101 is of a transmissive type, in order to obtain a higher luminous flux, the light emitting material is preferably dispersed in the green light emitting portion 106 and the red light emitting portion 107 as appropriate. On the other hand, the light emitted from the backlight unit 101 (ie, the blue light source 108, the green light emitting unit 106 and the red light emitting unit 107) is the green light emitting unit 106 or the red light emitting unit 107. Is emitted to the outside of the backlight unit without passing through (see Fig. 8), in order to obtain a higher luminous flux, the light emitting material is preferably filled at a high density. Therefore, the composition of the luminescent material should be set according to the use of the display device, the kind and physical properties of the luminescent material, the kind or viscosity of the binder, and the like while taking these into consideration.

In addition, the light emission color of the white light emitted by the backlight unit 101 is not only normal white light having a chromaticity coordinate (x, y) of (0.33, 0.33), but also image formation of a liquid crystal panel, a display panel, a diffusion plate, a light guide plate, etc. to be combined. It can be changed arbitrarily to correct the transmission characteristics of the unit, for example, the color coordinates (x, y) are surrounded by (0.28, 0.25), (0.25, 0.28), (0.34, 0.40) and (0.40, 0.34) A luminous color within the area is also possible.

[II-1-4-4. Other ingredients]

In addition, other components may be contained in the light emitting material, and the green light emitting portion 106 and the red light emitting portion 107 may be formed of the light emitting substance, and a binder and other components suitably used.

There is no restriction | limiting in particular in other components, A well-known additive can be used arbitrarily. For example, the same thing as the above-mentioned light emitting device can be used.

[II-1-4-5. Manufacturing Method of Light Emitting Part]

There is no restriction | limiting in particular in the manufacturing method of the green light emitting part 106 and the red light emitting part 107, It can manufacture by arbitrary methods. For example, it is possible to manufacture similarly to the 1st light emitting part and the 2nd light emitting part in the above-mentioned light emitting device.

In addition, in this embodiment, both the green light emitting part 106 and the red light emitting part 107 shall be formed with the corresponding fluorescent substance and binder. In addition, when the blue light source 108 emits the appropriate blue light, when the light emitted from the backlight unit 101 is diffused through the diffuser plate 102, white light (that is, chromaticity coordinates (x = 0.33, y = 0.33) It is assumed that the quantity and type of each light emitting material, the dimensions of the green light emitting portion 106 and the red light emitting portion 107, and the like are set so that light can be obtained.

[II-2. Diffusion plate]

The diffusion plate 102 is a member that diffuses the light emitted from the backlight unit 101. As shown in FIG. 4, this diffuser plate 102 is formed between the backlight unit 101 and the image forming unit 103, and the light emitted from the backlight unit 101 is formed inside the diffuser plate 102. It is diffused and becomes white light, and is to be emitted to the image forming unit 103.

There is no restriction | limiting in the specific structure of the diffuser plate 102, A shape, a material, a dimension, etc. are arbitrary. Although a known diffusion plate can be used as appropriate, for example, a sheet having irregularities on the front and back is used. For example, a structure in which fine particles such as synthetic resin and glass are dispersed may be used in a binder such as a synthetic resin. In this case, light diffusion is caused to occur due to a difference in refractive index between the binder and the fine particles. In addition, the sheet, binder, fine particles, etc. used in this case are usually formed of the material which can permeate each component of white light emitted from the backlight unit 101, ie, blue light, green light, and red light.

In addition, in this embodiment, suppose that the sheet | seat transparent to visible light in which the unevenness | corrugation was formed in the front and back surface as the diffuser plate 102 is used.

[II-3. Image forming unit]

The image forming unit 103 is a member that irradiates the back side with the white light emitted by the backlight unit 101 to form an image on the surface side. There is no limitation as long as it can form any image and transmit at least part of the illuminated backlight, and any known member having any shape, dimension, material, or the like can be used.

As a specific example of the image forming unit 103, the liquid crystal unit used for a liquid crystal display etc., the mark used for an internal illumination mark, etc. are mentioned.

For example, as an example of a liquid crystal unit, the liquid crystal layer in which a color filter, a transparent electrode, an alignment film, a liquid crystal, an alignment film, and a transparent electrode superimposed in the said order is hold | maintained in containers, such as glass cells with a polarizing film in the front and back. The structure of the structure is mentioned. In this case, in the liquid crystal unit, the molecular arrangement of the liquid crystal is controlled by an electrode applied to the transparent electrode to form an image. In this case, the above-described backlight unit 101 is formed by the white light (backlight) from the rear surface of the liquid crystal unit. By reflecting, the image formed in the liquid crystal unit can be clearly displayed on the surface side of the liquid crystal unit.

The position at which the display device displays the image formed in the image forming unit may be the surface side of the image forming unit, and in addition to displaying the image directly on the surface side of the image forming unit, the image is projected and displayed on any projection surface. You may also As an example of such a thing, a liquid crystal projector etc. are mentioned, for example.

In addition, for example, when using a mark as an image forming unit, the above-mentioned backlight unit 101 illuminates a mark with white light (backlight) from the back surface, and the image formed in the mark is made clear on the surface side of the mark. Can be displayed.

In addition, the image formed in the image forming unit 103 may be arbitrary, and may be a character or an image.

In this embodiment, the liquid crystal unit which displays an image directly on the surface is used as the image forming unit 103. As shown in FIG.

[II-4. effect]

Since the display device of the present embodiment has the same configuration as described above, the wiring 109 and the electrode (so as to emit the desired white light to the blue light source 108 of the backlight unit 101 at the time of use). 110) to supply appropriate power. The powered blue light source 8 emits blue light of intensity according to the supplied power, a part of which is emitted to the diffuser plate 102 as one component of white light, and the other part of the corresponding green light emitting part 106. Or by the light emitting material in the red light emitting portion 107.

In the green light emitting portion 106, the light emitting material is excited by the blue light absorbed and emits green light, which is emitted to the diffuser plate 102 as one component of the white light. In addition, the red light emitting unit 107 is excited by the red light absorbed by the light emitting material and emits red light, and this red light is also emitted to the diffusion plate 102 as one component of the white light. At this time, since the green light emitting part 106 and the red light emitting part 107 are formed independently of each other, the green light is not absorbed by the light emitting material in the red light emitting part 107, so that the luminous flux of the green light is lowered or The balance of the components of the white light is not disturbed.

Blue light, green light and red light emitted from the backlight unit 101 are incident on the diffuser plate 102, diffused from the diffuser plate 102, and emitted to the image forming unit 103. Since the light emitted from the backlight unit 101 is diffused in the diffuser plate 102 even if it is not diffused sufficiently before being incident on the diffuser plate 102 and is visible in different colors, the image forming unit At the time when it is emitted to 103, white light becomes good white light visible.

In the image forming unit 103, the white light emitted from the diffuser plate 102 is irradiated to the rear surface. Thereby, the image formed in the image forming unit 103 is clearly reflected on the surface of the image forming unit 103. At this time, since the white light contains blue, green and red light as components, and the balance of the components of the white light is well maintained, the color reproducibility when the image formed in the image forming unit 103 is illuminated is very good. It becomes.

In addition, since the green light is prevented from being absorbed by the light emitting material in the red light emitting portion 107, the fall of the light beam can be suppressed, whereby the energy for generating the backlight is minimized. That is, it becomes possible to improve the luminous efficiency of a backlight.

[II-5. Etc]

As mentioned above, although demonstrated in detail, the display apparatus of this invention is not limited to said 3rd embodiment, It can carry out by changing arbitrarily in the range which does not deviate from the summary of this invention.

For example, the green light emitting portion 106 or the red light emitting portion 107 may be formed in a reflective type as shown in FIG. 8. That is, in the configuration of FIG. 8, the blue light source 108 is formed away from the substrate 104 by the beam 111, and the green light emitting portion 106 and the red light emitting portion 107 are recessed in the substrate 4. The coating is formed on the minor surface. In addition, the wiring 109 and the electrode 110 are formed on the surface of the substrate 104 and the beam 111 so that electric power can be supplied to the blue electrode 108. In addition, the green light emitting part 106 and the red light emitting part 107 of FIG. 8 are comprised similarly to 3rd Embodiment mentioned above. In this case, a part of the blue light emitted from the blue light source 108 is emitted toward the image forming unit 103 as one component of the white light, and the other part is emitted toward the green light emitting portion 106 and the red light emitting portion 107. Become. The green light emitting portion 106 and the red light emitting portion 107 formed on the concave portion surface are excited by blue light and emit green light and red light, whereby the backlight unit 101 can emit white light. In addition, since the green light emitting portion 106 and the red light emitting portion 107 are formed independently of each other, the green light is not absorbed by the light emitting material in the red light emitting portion 107, so that the luminous flux of the green light is lowered, The balance of the components of the white light can be suppressed from being disturbed. In addition, in FIG. 8, the site | part shown with the same code | symbol as FIG. 4-7 shows the same thing as FIG.

Further, for example, the green light emitting portion 106 or the red light emitting portion 107 may be formed using a surface mount type frame. Depending on the use of the display device, the backlight unit 101 using the surface mount type frame may be used in many cases.

If the specific structure of the light emission part 105 using the surface mount type frame is illustrated, what is shown in FIG. 9 is mentioned, for example. 9 is sectional drawing which shows typically an example of the structure of the light emitting part 105 using the surface mount type frame, and the site | part shown with the same code | symbol as FIG. 4-8 is the same as that of FIG. Indicates.

In the configuration of FIG. 9, the green light emitting portion 106 and the red light emitting portion 107 formed in the frame 112 are attached to one side of the substrate 104, and the green light emitting portion 106 and the red light emitting portion ( 107 forms the light emitting portion 105 in pairs.

The frame 112 not only transmits the green light emitted from the green light emitting part 106 but also the shape, dimension, and material (including the points paying attention to heat dissipation, color, and reflectance). It is preferable to form in the same manner as the substrate 104 described in detail in the form. In the configuration of FIG. 9, the light emitting portion 105 includes a pair of frames 112, each frame 112 is formed in a cup shape having a recessed portion, and connects the bottom of the recessed portion with the bottom of the frame 112. The wiring 113 formed so that it may be provided may be provided. In the pair of frames 112, blue light sources 108 connected to the wirings 113 are formed, respectively, and one frame 112 is filled with a green light emitting material and a binder, and a green light emitting part is provided. It is assumed that 106 is formed, and the other frame 112 is filled with a red light emitting material and a binder to form a red light emitting portion 107. In addition, a through hole 114 is formed in the substrate 104, and the electrode 110 is attached to the through hole 114. The electrode 110 is also capable of supplying electric power from the wiring 109 formed on the rear surface of the substrate 104, and the electrode 110 and the wiring 113 of the frame 112 are connected by the solder 115. Thus, power can be supplied to the blue power supply 108. In addition, the solder 115 has a function of fixing the green light emitting portion 106 and the red light emitting portion 107 to the substrate 104 in addition to supplying power to the blue light source 108, and the green light emitting portion 106. And a function of dissipating heat generated by the red light emitting portion 107.

Even when the light emitting portion 105 is formed using the surface mount type frame in this manner, a part of the blue light emitted from the blue light source 108 is emitted toward the image forming unit 103 as one component of the white light, and the other Some are emitted toward the green light emitting portion 106 and the red light emitting portion 107. Then, the green light emitting portion 106 and the red light emitting portion 107 formed in the recessed portion are excited by blue light and emit green light and red light, whereby the backlight unit 101 can emit white light. In addition, since the green light emitting portion 106 and the red light emitting portion 107 are formed independently of each other, green light is not absorbed by the light emitting material in the red light emitting portion 107 at the time of light emission, and therefore, the luminous flux of green light. It can suppress that this fall or the balance of the component of white light is disturbed.

For example, you may make it use the light guide plate which guides the white light from the backlight unit 101 to the image forming unit 103. When the light guide plate is used, it is possible to arrange the backlight unit 101 at a position other than the position corresponding to the image forming unit 103 as in the above-described embodiment, thereby increasing the degree of freedom in designing the display device. Moreover, there is no restriction | limiting in the light guide plate, The well-known light guide plate can be used arbitrarily, including using a mirror, a prism, a lens, an optical fiber, etc.

10 is a cross-sectional view schematically illustrating the configuration of a display device using a light guide plate. When the light guide plate is used, for example, as shown in FIG. 10, the backlight unit 101 can be formed on the side of the image forming unit 103. That is, in the structure of FIG. 10, the light guide plate 117 which has the reflective film 116 in the back surface is used, and the white light which entered from the side (right side of the figure) of the light guide plate 117 is reflected by the reflective film 116, It is guided toward the diffuser plate 102 of the front (upper side in drawing). When the display device is configured as shown in FIG. 10, the backlight unit 101 can be formed on the side of the image forming unit 103. In addition, the site | part shown by the code | symbol same as the code | symbol used in FIGS. 4-9 in FIG. 10 shows the same thing as FIG.

For example, the display device may be provided with another member. For example, an antireflection film, a view expansion film, a brightness enhancement film, a lens sheet, a protective cover, a heat sink and the like can be appropriately attached.

In addition, the structure described in the description of the light emitting device and the structure described in the description of the display device may be combined or implemented in combination with each of the above-described embodiments and modifications.

Moreover, you may implement | achieve the structure of 3rd Embodiment with the light source or light emitting substance which emits light other than blue, red, and green.

The third light emitting unit may be formed in the above-described light emitting device, or the yellow light emitting unit may be formed in the backlight unit, so that the light emitting device or the backlight unit may be provided with three or more light emitting units, respectively.

EXAMPLES Hereinafter, although an Example is shown and this invention is demonstrated in more detail, this invention is not limited to a following example, It can implement by modifying arbitrarily in the range which does not deviate from the summary of this invention.

Example 1

(Production of Green Light Emitting Part)

The green light emitting part was manufactured so that the chromaticity coordinates of the synthetic light (short wavelength light) of blue light and green light emitted from the green light emitting part might be (x, y) = (0.25, 0.35). Specifically, it was as follows.

As a frame as shown in Fig. 9, a surface mount type frame having a recess having a diameter of about 2.5 mm and a depth of about 0.9 mm is used, and at the bottom of the recess of the frame, a blue LED (C460MB, manufactured by Cree) as a blue light source. Was attached and power was supplied to the blue light source from the back of the substrate. In addition, a concave portion mounting the blue light source, the light-emitting substance is _{Ca 2 .94 Ce 0 .06 Sc 1} .94 Mg 0 .06 Si 3 O 12 , and a binder to a silicon resin filling a paste mixed green light-emitting portion Prepared. At this time, the mixing ratio of the luminescent material and the binder was about 95: 5 by weight.

(Production of Red Light Emitting Part)

The red light emitting part was manufactured so that the chromaticity coordinates of the synthetic light (long wavelength light) of blue light and red light emitted from the red light emitting part might be (x, y) = (0.56, 0.27). Specifically, as the light emitting material _{Ca 0 .992 AlSiEu 0 .08 N 2} .85 O 0. _{Using 15} , the red light-emitting part was manufactured in the same manner as the green light-emitting part, except that the mixing ratio of the light-emitting material and the binder was about 98: 2 by weight.

(Measurement of white light)

20 전류 of current is supplied to the blue LEDs of the green light emitting part and the red light emitting part to emit light, and the integrals for the spectrometer HR2000 and the LED manufactured by Ocean Optics are respectively applied to the light emitted from the green light emitting part and the red light emitting part. The emission spectrum distribution was measured using a sphere. At this time, it was confirmed that the chromaticity coordinates of the emitted light became the chromaticity coordinates respectively set.

On the basis of the measurement results, from the light emitted from the green light emitting part and the red light emitting part, white light having a chromaticity coordinate of (x, y) = (0.33, 0.33) is synthesized, and the light emission intensity distribution with respect to the wavelength of the white light is determined. Calculated. That is, as shown in FIG. 11, the chromaticity coordinates are located on a line segment connecting the chromaticity coordinates of the light (short wavelength light) emitted from the green light emitting part and the chromaticity coordinates of the light (long wavelength light) emitted from the red light emitting part. In order to synthesize | combine white light, the calculation which synthesize | combines by adjusting the intensity | strength of the light emitted from a green light emitting part and a red light emitting part was performed. In this embodiment, the spectral ratio of the light from the green light emitting portion to the light from the red light emitting portion is set to 0.48: 0.52. The distribution obtained as a result of calculation is shown in FIG. 11 is a chromaticity diagram for explaining the method of synthesizing white light in Examples 1 to 4, wherein the plots at both ends of each line segment show the light emitted from the green light emitting portion and the red light emitting portion in each example. Represents chromaticity coordinates, respectively.

In addition, the total luminous flux of white light was 1.2 lm per blue LED.

Example 2

The green light emitting part was the same as in Example 1 except that the mixing ratio of the luminescent material and the binder was adjusted so that the chromaticity coordinates of the blue light and the green light (short wavelength light) were (x, y) = (0.27, 0.39). Prepared.

In addition, except that the mixing ratio of the luminescent material and the binder was adjusted so that the chromaticity coordinates of the synthesized light (long wavelength light) of the blue light and the red light became (x, y) = (0.45, 0.22), A light emitting part was prepared.

White light was synthesized in the same manner as in Example 1 except that the chromaticity coordinates of the white light to be synthesized were (x, y) = (0.32, 0.33), and the light emission intensity distribution for the wavelength was calculated. In this embodiment, the spectral ratio of the light from the green light emitting portion to the light from the red light emitting portion is set to 0.50: 0.50. The distribution obtained as a result of the calculation is shown in FIG. 13.

In addition, the total luminous flux of white light was 1.3 lm per blue LED.

Example 3

A green light emitting part was produced in the same manner as in Example 1 except that the mixing ratio of the luminescent material and the binder was adjusted so that the chromaticity coordinates of the blue light and the green light (short wavelength light) were (x, y) = (0.28, 0.42). Prepared.

In addition, except that the mixing ratio of the luminescent material and the binder was adjusted so that the chromaticity coordinates of the synthetic light (long wavelength light) of the blue light and the red light were (x, y) = (0.42, 0.21), A light emitting part was prepared.

In the same manner as in Example 1, white light was synthesized, and the light emission intensity distribution with respect to the wavelength was calculated. In this embodiment, the spectral ratio of the light from the green light emitting portion to the light from the red light emitting portion is set to 0.47: 0.53. The distribution obtained as a result of the calculation is shown in FIG.

In addition, the total luminous flux of white light was 1.3 lm per blue LED.

Example 4

Green light emission was the same as in Example 1, except that the mixing ratio of the luminescent material and the binder was adjusted so that the chromaticity coordinates of the blue light and the green light (short wavelength light) were (x, y) = (0.30, 0.47). Part was prepared.

In addition, except that the mixing ratio of the luminescent material and the binder was adjusted so that the chromaticity coordinates of the synthesized light (long wavelength light) of the blue light and the red light were (x, y) = (0.38, 0.18), A light emitting part was prepared.

In the same manner as in Example 1, white light was synthesized, and the light emission intensity distribution with respect to the wavelength was calculated. In this embodiment, the spectral ratio of the light from the green light emitting part to the light from the red light emitting part is set to 0.46: 0.54. The distribution obtained as a result of the calculation is shown in FIG. 15.

In addition, the total luminous flux of white light was 1.3 lm per blue LED.

Example 5

As a luminescent material that emits green light _{Ca 2 .94 Ce 0 .06 Sc 2} Si 3 O 12 In the same manner as in Example 1, except that the mixing ratio of the luminescent material and the binder was adjusted so that the chromaticity coordinates of the synthesized light (short wavelength light) of the blue light and the green light became (x, y) = (0.24, 0.37). , A green light emitting part was prepared.

In addition, except that the mixing ratio of the luminescent material and the binder was adjusted so that the chromaticity coordinates of the synthesized light (long wavelength light) of the blue light and the red light were (x, y) = (0.52, 0.23), A light emitting part was prepared.

In the same manner as in Example 1, white light was synthesized, and the light emission intensity distribution with respect to the wavelength was calculated. In this embodiment, the spectral ratio of the light from the green light emitting portion to the light from the red light emitting portion is set to 0.52: 0.48. Moreover, the chromaticity diagram for demonstrating the synthesis | combining method of the white light in Examples 5-7 is shown in FIG. In this FIG. 16, similarly to FIG. 11, the plot of the both ends of each line segment shows the chromaticity coordinates of the light emitted from the green light emitting part and the red light emitting part in each Example, respectively. 17 shows the distribution obtained as a result of the calculation.

In addition, the total luminous flux of white light was 1.0 lm per blue LED.

Example 6

A green light emitting part was produced in the same manner as in Example 5 except that the mixing ratio of the luminescent material and the binder was adjusted so that the chromaticity coordinates of the blue light and the green light (short wavelength light) were (x, y) = (0.25, 0.40). Prepared.

In addition, except that the mixing ratio of the luminescent material and the binder was adjusted so that the chromaticity coordinates of the synthesized light (long wavelength light) of the blue light and the red light became (x, y) = (0.45, 0.22), A light emitting part was prepared.

In the same manner as in Example 1, white light was synthesized, and the light emission intensity distribution with respect to the wavelength was calculated. In this embodiment, the spectral ratio of the light from the green light emitting portion to the light from the red light emitting portion is set to 0.54: 0.46. The distribution obtained as a result of the calculation is shown in FIG. 18.

In addition, the total luminous flux of white light was 1.0 lm per blue LED.

Example 7

A green light emitting part was produced in the same manner as in Example 5 except that the mixing ratio of the luminescent material and the binder was adjusted so that the chromaticity coordinates of the blue light and the green light (short wavelength light) were (x, y) = (0.26, 0.42). Prepared.

In addition, except that the mixing ratio of the luminescent material and the binder was adjusted so that the chromaticity coordinates of the synthetic light (long wavelength light) of the blue light and the red light were (x, y) = (0.42, 0.21), A light emitting part was prepared.

In the same manner as in Example 1, white light was synthesized, and the light emission intensity distribution with respect to the wavelength was calculated. In this embodiment, the spectral ratio of the light from the green light emitting portion to the light from the red light emitting portion is set to 0.54: 0.46. The distribution obtained as a result of the calculation is shown in FIG. 19.

In addition, the total luminous flux of white light was 1.0 lm per blue LED.

Example 8

A green light emitting part was produced in the same manner as in Example 1 except that the mixing ratio of the luminescent material and the binder was adjusted so that the chromaticity coordinates of the blue light and the green light (short wavelength light) were (x, y) = (0.25, 0.35). Prepared.

Also, as a red light-emitting section luminescent material Sr _{0 .7936 .1984 0} Ca Eu _{0 .008} using AlSiN _3, the synthetic chromaticity coordinates of the light (long wavelength light) of blue light and red light (x, y) = (0.51, 0.29 In the same manner as in Example 1, except that the mixing ratio of the luminescent material and the binder was adjusted so as to be).

In the same manner as in Example 1, white light was synthesized, and the light emission intensity distribution with respect to the wavelength was calculated. In this embodiment, the spectral ratio of the light from the green light emitting portion to the light from the red light emitting portion is set to 0.48: 0.52. Moreover, the chromaticity diagram for demonstrating the synthesis | combining method of the white light in Examples 8-11 is shown in FIG. In this FIG. 20, similarly to FIG. 11 and FIG. 16, the plot of the both ends of each line segment shows the chromaticity coordinates of the light emitted from the green light emission part and the red light emission part in each Example, respectively. The distribution obtained as a result of the calculation is shown in FIG. 21.

The total luminous flux of white light was 1.3 lm per blue LED.

Example 9

The green light emitting part was the same as in Example 1 except that the mixing ratio of the luminescent material and the binder was adjusted so that the chromaticity coordinates of the blue light and the green light (short wavelength light) were (x, y) = (0.27, 0.39). Prepared.

In addition, except that the mixing ratio of the luminescent material and the binder was adjusted so that the chromaticity coordinates of the synthesized light (long wavelength light) of the blue light and the red light were (x, y) = (0.43, 0.24), A light emitting part was prepared.

In the same manner as in Example 1, white light was synthesized, and the light emission intensity distribution with respect to the wavelength was calculated. In this embodiment, the spectral ratio of the light from the green light emitting portion to the light from the red light emitting portion is set to 0.47: 0.53. The distribution obtained as a result of the calculation is shown in FIG. 22.

The total luminous flux of white light was 1.3 lm per blue LED.

Example 10

A green light emitting part was produced in the same manner as in Example 1 except that the mixing ratio of the luminescent material and the binder was adjusted so that the chromaticity coordinates of the blue light and the green light (short wavelength light) were (x, y) = (0.28, 0.42). Prepared.

In addition, except that the mixing ratio of the luminescent material and the binder was adjusted so that the chromaticity coordinates of the synthesized light (long wavelength light) of the blue light and the red light were (x, y) = (0.40, 0.22), A light emitting part was prepared.

In the same manner as in Example 1, white light was synthesized, and the light emission intensity distribution with respect to the wavelength was calculated. In this embodiment, the spectral ratio of the light from the green light emitting part to the light from the red light emitting part is set to 0.46: 0.54. The distribution obtained as a result of the calculation is shown in FIG.

The total luminous flux of white light was 1.4 lm per blue LED.

Example 11

A green light emitting part was produced in the same manner as in Example 1 except that the mixing ratio of the luminescent material and the binder was adjusted so that the chromaticity coordinates of the blue light and the green light (short wavelength light) were (x, y) = (0.30, 0.47). Prepared.

In addition, except that the mixing ratio of the luminescent material and the binder was adjusted so that the chromaticity coordinates of the synthesized light (long wavelength light) of the blue light and the red light were (x, y) = (0.36, 0.20), A light emitting part was prepared.

In the same manner as in Example 1, white light was synthesized, and the light emission intensity distribution with respect to the wavelength was calculated. In this embodiment, the spectral ratio of the light from the green light emitting portion to the light from the red light emitting portion is set to 0.45: 0.55. The distribution obtained as a result of the calculation is shown in FIG. 24.

The total luminous flux of white light was 1.4 lm per blue LED.

Example 12

A green light emitting part was produced in the same manner as in Example 5 except that the mixing ratio of the luminescent material and the binder was adjusted so that the chromaticity coordinates of the blue light and the green light (short wavelength light) were (x, y) = (0.24, 0.36). Prepared.

Also, as a red light-emitting section luminescent material Sr _{0 .7936 .1984 0} Ca Eu _{0 .008} using AlSiN _3, the synthetic chromaticity coordinates of the light (long wavelength light) of blue light and red light (x, y) = (0.48, 0.27 A red light emitting part was manufactured in the same manner as in Example 1, except that the mixing ratio of the light emitting material and the binder was adjusted to

In the same manner as in Example 1, white light was synthesized, and the light emission intensity distribution with respect to the wavelength was calculated. In this embodiment, the spectral ratio of the light from the green light emitting portion to the light from the red light emitting portion is set to 0.52: 0.48. Moreover, the chromaticity diagram for demonstrating the synthesis | combining method of the white light in Examples 12-14 is shown in FIG. In FIG. 25, similarly to FIG. 11, FIG. 16, and FIG. 20, the plots at both ends of the line segments represent chromaticity coordinates of the light emitted from the green light emitting portion and the red light emitting portion in each example. The distribution obtained as a result of the calculation is shown in FIG. 26.

The total luminous flux of white light was 1.1 lm per blue LED.

Example 13

A green light emitting part was produced in the same manner as in Example 5 except that the mixing ratio of the luminescent material and the binder was adjusted so that the chromaticity coordinates of the blue light and the green light (short wavelength light) were (x, y) = (0.26, 0.42). Prepared.

In addition, except that the mixing ratio of the luminescent material and the binder was adjusted so that the chromaticity coordinates of the synthesized light (long wavelength light) of the blue light and the red light were (x, y) = (0.42, 0.24), A light emitting part was prepared.

In the same manner as in Example 1, white light was synthesized, and the light emission intensity distribution with respect to the wavelength was calculated. In this embodiment, the spectral ratio of the light from the green light emitting portion to the light from the red light emitting portion is set to 0.51: 0.49. The distribution obtained as a result of the calculation is shown in FIG. 27.

The total luminous flux of white light was 1.1 lm per blue LED.

Example 14

A green light emitting part was produced in the same manner as in Example 5 except that the mixing ratio of the luminescent material and the binder was adjusted so that the chromaticity coordinates of the blue light and the green light (short wavelength light) were (x, y) = (0.27, 0.45). Prepared.

In addition, except that the mixing ratio of the luminescent material and the binder was adjusted so that the chromaticity coordinates of the synthesized light (long wavelength light) of the blue light and the red light became (x, y) = (0.40, 0.22), A light emitting part was prepared.

In the same manner as in Example 1, white light was synthesized, and the light emission intensity distribution with respect to the wavelength was calculated. In this embodiment, the spectral ratio of the light from the green light emitting portion to the light from the red light emitting portion is set to 0.52: 0.48. The distribution obtained as a result of the calculation is shown in FIG. 28.

The total luminous flux of white light was 1.1 lm per blue LED.

[theorem]

From the above, it was confirmed that when the green light emitting portion and the red light emitting portion were formed independently, it was possible to emit white light at a high luminous flux. In addition, these white light include blue, green and red light, and therefore, when the backlight unit having the green light emitting part and the red light emitting part formed independently of each other as described above is used, the light emission efficiency is good and the color reproducibility is excellent. A display device can be obtained.

INDUSTRIAL APPLICABILITY The present invention can be used in any field using light, and can be used, for example, in addition to indoor and outdoor lightings, and image display devices of various electronic devices such as mobile phones, home electronics, outdoor installation displays, liquid crystal displays, and liquid crystal projectors. It is suitable for use in interior lighting, etc.

While the invention has been described in detail with reference to specific embodiments, it will be apparent to those skilled in the art that various changes may be made without departing from the spirit and scope of the invention.

In addition, the present application is a Japanese patent application filed on June 30, 2004 (Japanese Patent Application 2004-194154), and a Japanese patent application filed on October 18, 2004 (Japanese Patent Application 2004-303363) Is based on, the entirety of which is incorporated by reference.

Claims (9)

Light source, A first light emitting portion containing at least one light emitting material which is excited by the light emitted by the light source and can emit light containing a component having a longer wavelength than the light emitted by the light source; A second light emitting part containing at least one light emitting material which is excited by light emitted from the light source and the first light emitting part and emits light containing a component having a longer wavelength than that emitted by the first light emitting part; And a light shielding portion that prevents at least a part of the light emitted from the first light emitting portion from being incident on the second light emitting portion. The method of claim 1, And the light shielding portion reflects at least a portion of the light emitted from the first light emitting portion. The light-emitting device of Claim 1 or 2 was used, The illumination characterized by the above-mentioned. A light emitting device according to claim 1 or 2, wherein the backlight unit for a display device is used. A display device comprising the light emitting device according to claim 1 or 2. A backlight unit emitting a backlight; A display device comprising an image forming unit which irradiates the backlight on the back side and forms an image on the surface side, wherein the backlight emitted from the backlight unit is provided. The backlight unit, Light source, A first light emitting portion containing at least one light emitting material which is excited by the light emitted by the light source and can emit light containing a component having a longer wavelength than the light emitted by the light source; At least one type of light emission that is formed at least partially independently from the first light emitting portion and is excited by light emitted from the light source and the first light emitting portion and emits light containing a component having a longer wavelength than light emitted from the first light emitting portion And a second light emitting unit containing a material. A backlight unit emitting white light, A display device comprising an image forming unit which irradiates the white light emitted from the backlight unit to the back side and forms an image on the surface side, The backlight unit, A blue light source emitting blue light, A green light emitting part having a green light emitting body excited by the blue light and emitting light, and emitting green light; And a red light emitting part which is formed at least partially independently from the green light emitting part, has a red light emitting body excited and emitted by the blue light, and emits red light. The method according to claim 6 or 7, And a diffuser plate between the backlight unit and the image forming unit to diffuse light emitted from the backlight unit. The method according to any one of claims 6 to 8, And a light guide plate for guiding light from the backlight unit to the image forming unit.

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