WO2016158723A1

WO2016158723A1 - Optical member, illumination device, display device, television reception device, and manufacturing method for optical member

Info

Publication number: WO2016158723A1
Application number: PCT/JP2016/059559
Authority: WO
Inventors: 健太郎鎌田
Original assignee: シャープ株式会社
Priority date: 2015-04-01
Filing date: 2016-03-25
Publication date: 2016-10-06

Abstract

This optical member is provided with: a wavelength conversion layer 151 that contains an acrylic resin and a quantum dot fluorescent body dispersed in the acrylic resin; a pair of first supporting layers 152, 152 that are formed from a polyester resin and sandwich the wavelength conversion layer 151; and a pair of barrier layers 153, 153 that are formed from a metal oxide film, are disposed further outward than the first supporting layers 152, and sandwich the wavelength conversion layer 151 via the first supporting layers 152.

Description

OPTICAL MEMBER, LIGHTING DEVICE, DISPLAY DEVICE, TV RECEPTION DEVICE, AND OPTICAL MEMBER MANUFACTURING METHOD

The present invention relates to an optical member, a lighting device, a display device, a television receiver, and an optical member manufacturing method.

An illumination device using a phosphor film containing a quantum dot phosphor (Quantum Dot Phosphor) as an optical member is known (for example, Patent Document 1). In this type of lighting device, when primary light (for example, blue light) emitted from a light source is supplied to a phosphor film, a part of the light excites the quantum dot phosphor in the film, and the rest Light will be transmitted through the film. When the quantum dot phosphor is excited by the primary light, secondary light (green light and red light) having a wavelength different from that of the primary light is emitted from the quantum dot phosphor. Since the secondary light emitted from the film is mixed with the primary light transmitted through the film, white light is emitted from the phosphor film as a result.

In the phosphor film, the quantum dot phosphor is dispersed in the binder resin layer. And the barrier layer for protecting a quantum dot fluorescent substance from moisture, air, etc. is each laminated | stacked on the both surfaces side of the binder resin layer (refer patent document 1). This type of barrier layer is generally made of a metal oxide film such as alumina.

Special table 2013-544018 gazette

(Problems to be solved by the invention)
Although the barrier layer has a function of shielding oxygen and moisture, there are cases where sufficient adhesion to the binder resin layer cannot be obtained. In such a case, the barrier layer may be peeled off from the binder resin layer, which is a problem. For example, when the barrier layer is partially peeled from the binder resin layer, air and moisture are likely to accumulate at such a peeled portion, so that the quantum dot phosphor in the binder resin layer cannot be protected. There is a possibility that optical unevenness due to the air layer may occur.

An object of the present invention is to provide a technique capable of reliably protecting a binder resin layer containing a quantum dot phosphor with a barrier layer.

(Means for solving the problem)
An optical member according to the present invention includes a wavelength conversion layer that includes an acrylic resin, a quantum dot phosphor dispersed in the acrylic resin, and a pair of first resins that sandwich the wavelength conversion layer. A support layer and a pair of barrier layers which are made of a metal oxide film and are arranged outside the first support layer and sandwich at least the wavelength conversion layer via the first support layer. As described above, since the wavelength conversion layer containing the acrylic resin is sandwiched between the pair of first support layers made of the polyester resin, the wavelength conversion layer containing the acrylic resin is assumed to be a gold-loss oxide. Compared with the case where it is configured to be sandwiched between a pair of barrier layers made of a film, the adhesiveness between the wavelength conversion layer and the first support layer is high. And it can avoid that a barrier layer contacts a wavelength conversion layer directly by setting it as the arrangement | positioning which at least a 1st support layer interposes between a barrier layer and a wavelength conversion layer. As a result, a situation where the barrier layer is peeled off is avoided. Thereby, it becomes possible to prevent more reliably that the quantum dot fluorescent substance contained in a wavelength conversion layer contacts and degrades with moisture, oxygen, etc. by a barrier layer.

In the optical member, the barrier layer may be laminated on the first support layer. In this way, since the structure is simple, the tact time for manufacturing is shortened and the manufacturing cost can be reduced. In this way, the overall thickness of the optical member can be reduced.

In the optical member, made of a polyester-based resin, the barrier layer is laminated, the barrier layer is arranged on the inner side, or the barrier layer is arranged on the outer side, than the first support layer. When the pair of second support layers disposed on the outside and the barrier layer are disposed on the inside, the barrier layer is disposed on the outside, interposed between the first support layer and the barrier layer. A pair of adhesive layers interposed between the first support layer and the second support layer may be provided. In this way, the light is likely to be multiple-reflected, so that the light conversion efficiency by the quantum dot phosphor is high. Thereby, since content of the quantum dot fluorescent substance in a wavelength conversion layer can be reduced, it is suitable when aiming at cost reduction.

In the optical member, the barrier layer may be formed by physical vapor deposition or chemical vapor deposition.

In the optical member, the quantum dot phosphor may include at least a green quantum dot phosphor that emits light in a green wavelength region.

In the optical member, the quantum dot phosphor may include at least a red quantum dot phosphor that emits light in a red wavelength region.

In the optical member, the wavelength conversion layer may include a scattering agent.

Further, an illumination device according to the present invention includes any one of the optical members described above and a light source that emits excitation light that excites the quantum dot phosphor included in the wavelength conversion layer.

The display device according to the present invention includes the illumination device and a display panel that displays an image using light supplied from the illumination device.

In the display device, the display panel may be a liquid crystal panel.

The television receiver according to the present invention comprises the display device.

Moreover, the manufacturing method of the optical member which concerns on this invention is equipped with the 1st support layer which consists of polyester resin, and the barrier layer which is laminated | stacked on one surface of this 1st support layer, and consists of a film | membrane of a metal oxide. On the surface of the first support layer in one of the first unit members, a composition liquid in which quantum dot phosphors are dispersed in an ultraviolet curable acrylic resin is applied. An application layer forming step of forming an application layer made of the applied product, and a bonding step of bonding the other first unit member so as to sandwich the application layer between the one first unit member. And a curing step of irradiating the coating layer through the first unit with ultraviolet rays to cure the coating layer to obtain a wavelength conversion layer.

The optical member manufacturing method according to the present invention includes a pair of a wavelength conversion layer including an acrylic resin and a quantum dot phosphor dispersed in the acrylic resin, and a polyester resin sandwiching the wavelength conversion layer. An adhesive layer forming step for forming an adhesive layer on both surfaces of a second unit member having a first support layer, a second support layer made of a polyester-based resin, and lamination on one surface of the second support layer A pair of third unit members each having a barrier layer made of a metal oxide film, in such a manner that the barrier layer is disposed on the inner side or the barrier layer is disposed on the outer side. And a bonding step of bonding to the agent layer.

In the adhesive layer forming step, the adhesive layer may be made of an OCA film.

In the optical member manufacturing method, the barrier layer may be formed by physical vapor deposition or chemical vapor deposition.

(The invention's effect)
ADVANTAGE OF THE INVENTION According to this invention, the technique which can protect reliably the binder resin layer containing quantum dot fluorescent substance with a barrier layer can be provided.

1 is an exploded perspective view showing a schematic configuration of a television receiver according to Embodiment 1 of the present invention. AA line sectional view of FIG. Cross-sectional view schematically showing a part of the structure of the phosphor sheet Explanatory drawing which shows an example of the manufacturing method of a fluorescent substance sheet Sectional drawing which represented a part of structure of the fluorescent substance sheet which concerns on Embodiment 2 typically Explanatory drawing which shows an example of the manufacturing method of the fluorescent substance sheet which concerns on Embodiment 2. FIG. Sectional drawing which represented a part of structure of the fluorescent substance sheet which concerns on Embodiment 3 typically Sectional drawing which represented typically the schematic structure of the liquid crystal display device with which the fluorescent substance sheet which concerns on Embodiment 4 is utilized.

<Embodiment 1>
Embodiment 1 of the present invention will be described with reference to FIGS. In the present embodiment, a phosphor sheet used as the optical member 15 in the liquid crystal display device 10 such as the television receiver 10TV is illustrated. For convenience of explanation, an X axis, a Y axis, and a Z axis are shown in a part of each drawing.

First, a television receiver 10TV and a liquid crystal display device 10 using a phosphor sheet will be described with reference to FIGS. FIG. 1 is an exploded perspective view showing a schematic configuration of a television receiver 10TV according to Embodiment 1 of the present invention, and FIG. 2 is a cross-sectional view taken along line AA of FIG.

As shown in FIG. 1, the television receiver 10TV mainly includes a liquid crystal display device (an example of a display device) 10 and both front and back cabinets 10Ca and 10Cb that hold the liquid crystal display device 10 so as to be sandwiched from both front and rear (front and back) sides. A power source 10P, a tuner (reception unit) 10T that receives a television signal, and a stand 10S.

The liquid crystal display device 10 of the present embodiment generally has a horizontally long rectangular shape extending long in the left-right direction. Further, as shown in FIG. 2, the liquid crystal display device 10 mainly includes a liquid crystal panel 11 used as a display panel, and a backlight device (illumination device) as an external light source that supplies light to the liquid crystal panel 11. 12 and a frame-like bezel 13 for holding the liquid crystal panel 11, the backlight device 12, and the like.

The liquid crystal panel 11 mainly comprises a pair of transparent substrates and a liquid crystal layer sealed in a form sandwiched between them, using light emitted from the backlight device 12, An image is displayed on the panel surface in a visible state. The liquid crystal panel 11 generally has a horizontally long rectangular shape in plan view. One of the pair of substrates constituting the liquid crystal panel 11 is an array substrate, and TFTs (Thin Film Transistors), pixel electrodes, etc., which are switching elements, are arranged in a matrix on a transparent glass substrate. It consists of the set. The other substrate is a color filter (hereinafter referred to as CF) substrate, which is formed by arranging color filters of red, green, and blue in a matrix on a transparent glass substrate.

The backlight device 12 is a device that is arranged on the back side of the liquid crystal panel 11 and supplies light toward the liquid crystal panel 11. The backlight device 12 is configured to emit white light. Note that the backlight device 12 of the present embodiment is a so-called edge light type (or side light type).

As shown in FIG. 2, the backlight device 12 includes a chassis 14, an optical member 15, a frame 16, an LED 17, an LED substrate 18, a light guide plate 19, a reflection sheet 20, and the like.

The chassis 14 has a substantially box shape opened to the front side, and is made of, for example, a metal plate such as an aluminum plate or an electrogalvanized steel plate (SECC). Various members such as the LED 17, the LED substrate 18, the reflection sheet 20, the light guide plate 19, and the optical member 15 are accommodated inside the chassis 14. In the chassis 14, the reflection sheet 20, the light guide plate 19, and the optical member 15 are accommodated in a state of being stacked in this order from the back side. A board such as a control board and an LED driving board (not shown) is attached to the outside of the chassis 14.

The optical member 15 has a horizontally long and substantially rectangular shape in plan view, like the liquid crystal panel 11 and the like. The optical member 15 is placed on the front side of the light guide plate 19 so as to be arranged on the back side of the liquid crystal panel 11. The optical member 15 has a function of transmitting light emitted from the light guide plate 19 to the liquid crystal panel 11 side while providing a predetermined optical action. The optical member 15 is composed of a plurality of sheet-like members (optical sheets) stacked on each other.

Specific members (optical sheets) constituting the optical member 15 include, for example, a diffusion sheet, a lens sheet, a reflective polarizing sheet, and the like. In particular, the optical member 15 of the present embodiment includes a phosphor sheet 150 containing a quantum dot phosphor as an essential member (optical sheet). The phosphor sheet 150 will be described later.

The frame 16 has a frame shape (frame shape) covering the outer peripheral end of the light guide plate 19 and is assembled to the opening portion of the chassis 14 from the front side. The frame 16 is made of synthetic resin, for example.

The reflection sheet 20 is a light-reflective sheet-like member, and is disposed in the chassis 14 so as to cover the bottom surface of the chassis 14. The reflection sheet 20 is made of, for example, a white foamed polyethylene terephthalate sheet.

The light guide plate 19 is made of a synthetic resin material (for example, acrylic resin such as PMMA, polycarbonate resin, etc.) that has a refractive index sufficiently higher than air, is transparent, and is excellent in light transmittance. Similar to the liquid crystal panel 11 and the like, the light guide plate 19 is made of a plate-like member having a substantially rectangular shape in plan view, the front surface 19 a faces the liquid crystal panel 11, and the back surface 19 c faces the reflection sheet 20. Is housed inside. The surface 19a of the light guide plate 19 is a light emitting surface 19a that emits light toward the liquid crystal panel 11 side. The optical member 15 described above is placed on the light emitting surface 19a. Among the optical members 15, the phosphor sheet 150 is disposed closest to the light emitting surface 19 a side.

LED (an example of a light source) 17 contains a chip-like blue LED element (blue light emitting element) that is a light emitting source, a transparent sealing material that seals the blue LED element, and a blue LED element and a sealing material. And a substantially box-shaped case portion configured to emit blue light. The blue LED element is a semiconductor made of, for example, IGaN, and light (ie, blue light) included in the wavelength region of blue light (about 420 nm to about 500 nm) when a voltage is applied in the forward direction. Is emitted.

The LED 17 is a so-called top emission type and is surface-mounted on a long LED substrate 18. A plurality of LEDs 17 are mounted on the LED substrate 18 so as to be arranged in a line at equal intervals. The LED 17 is housed in the chassis 14 so that the light emitting surface 17 a faces the long-side end surface 19 b of the light guide plate 19 in a state where the LED 17 is mounted on the LED substrate 18. Note that the two long side end surfaces 19b of the light guide plate 19 are light incident surfaces 19b on which light (blue light) from the LEDs 17 is incident.

Here, the phosphor sheet 150 will be described in detail. FIG. 3 is a cross-sectional view schematically showing a part of the configuration of the phosphor sheet 150. The phosphor sheet 150 is a kind of the optical member 15 and is used together with other members (optical sheets) constituting the optical member 15. The phosphor sheet 150 is disposed at a location closest to the light guide plate 19 among the plurality of members constituting the optical member 15. The phosphor sheet 150 has a substantially rectangular shape in plan view, like the liquid crystal panel 11 and the like.

The phosphor sheet 150 transmits a part of the light (blue light) from the LED 17 as it is, absorbs a part of the light (blue light) from the LED 17 and transmits the light (blue light) in another wavelength region. It has the function of converting to light and emitting it. Such a phosphor sheet 150 includes a wavelength conversion layer 151, a pair of first support layers 152, 152, and a pair of barrier layers 153, 153.

The wavelength conversion layer 151 contains an acrylic resin as a binder resin and a quantum dot phosphor blended in a dispersed state in the acrylic resin. The acrylic resin is transparent, has optical transparency, and has adhesion to the first support layer 152. As will be described later, the first support layer 152 is made of a polyester resin. Therefore, the acrylic resins can be adhered to the first support layer 152 by electrostatic action or the like.

Quantum dot phosphors are phosphors with excellent quantum efficiency. They confine electrons, holes, and excitons in all directions in a three-dimensional space in a nano-sized semiconductor crystal (for example, about 2 nm to 10 nm in diameter). The peak wavelength (emission color) of emitted light can be freely selected by changing the size of the dot having discrete energy levels.

In the case of the present embodiment, in the wavelength conversion layer 151, as the quantum dot phosphor, a green quantum dot phosphor that emits green light (wavelength region of about 500 nm to about 570 nm) and a red light (about 600 nm to about 780 nm). The red quantum dot phosphor that emits light in the wavelength region of (a). The emission spectrum of green light and the emission spectrum of red light emitted from the green quantum dot phosphor and the red quantum dot phosphor have sharp peaks, respectively, and their half-value widths are narrowed. The purity of each color of red light is extremely high, and the color gamut thereof is also widened.

The green quantum dot phosphor absorbs light from the LED 17 (blue light, excitation light) and is excited to emit green light (wavelength range of about 500 nm to about 570 nm). That is, the green quantum dot phosphor has a function of converting light (blue light, excitation light) from the LED 17 into other light (green light) having a different wavelength region.

The red quantum dot phosphor absorbs and excites light (blue light, excitation light) from the LED 17 and emits red light (wavelength range of about 600 nm to about 780 nm). That is, the red quantum dot phosphor has a function of converting light (blue light, excitation light) from the LED 17 into other light (red light) having a different wavelength region.

Materials used for the quantum dot phosphor include a combination of Zn, Cd, Pb and the like that can be a divalent cation and O, S, Se, Te, and the like that can be a divalent anion (for example, , Cadmium selenide (CdCe), zinc sulfide (ZnS), etc.), a combination of Ga, In, etc., which can be a trivalent cation, and P, As, Sb, etc., which can be a trivalent anion (for example, phosphorus Indium phosphide (InP), gallium arsenide (GaAs), and the like, and chalcopyrite type compounds (CuInSe _{2 and the} like). In this embodiment, CdSe is used as an example of the material of the quantum dot phosphor.

In this embodiment, the quantum dot phosphors (green quantum dot phosphor and red quantum dot phosphor) are dispersed and blended in the acrylic resin constituting the wavelength conversion layer 151 so as to be substantially uniform.

Note that the quantum dot phosphor is unstable with respect to moisture (moisture), oxygen, and the like, and when it comes into contact with them, the performance decreases. Therefore, the quantum dot phosphor in the wavelength conversion layer 151 is protected by the barrier layer 153 so as not to come into contact with water or oxygen as much as possible.

The wavelength conversion layer 151 may be blended with a scattering agent that scatters light incident on the wavelength conversion layer 151 or light emitted from the wavelength conversion layer 151 in addition to the acrylic resin and the quantum dot phosphor. Further, other components may be added to the wavelength conversion layer 151 as long as the object of the present invention is not impaired.

The first support layer 152 is made of a polyester resin such as polyethylene terephthalate (PET) or polybutylene terephthalate (PBT), and is made of a pair of layers sandwiching the wavelength conversion layer 151. The first support layer 152 is a sheet-like (film-like) member having a predetermined thickness, and is attached to each side of the wavelength conversion layer 151 one by one.

The first support layer 152 is bonded so as to sandwich the wavelength conversion layer 151 to support the wavelength conversion layer 151 and ensure the rigidity of the phosphor sheet 150. The first support layer 152 is transparent and has excellent light transmittance. In the present embodiment, the pair of first support layers 152, 152 are set to the same thickness.

The barrier layer 153 is made of a metal oxide film such as alumina or silicon oxide, and is disposed on the outer side of the first support layer 152. The pair of barrier layers 153 sandwich the wavelength conversion layer 151 from both sides via at least the first support layer 152. Consists of things.

The barrier layer 153 has a function (for example, oxygen barrier property, water vapor barrier property) of shielding a causative substance that degrades the quantum dot phosphor such as moisture and oxygen. The barrier layer 153 is made of a film (film) of a metal oxide such as alumina or silicon oxide, and includes, for example, a vacuum evaporation method (electron beam evaporation method, resistance heating evaporation method), sputtering method, ion plating method, ion beam. And chemical vapor deposition (CVD) methods such as physical vapor deposition (PVD) methods such as ion assisted methods and laser ablation methods, thermal CVD methods, photo CVD methods, and plasma CVD methods. In the barrier layer 153 of this embodiment, a film made of alumina is formed on the first support layer 152 by using a vacuum deposition method.

The barrier layer 153 is laminated in a state of being in close contact with the first support layer 152 made of a polyester resin. The barrier layer 153 is formed on the first support layer 152 because sufficient adhesion to the acrylic resin constituting the wavelength conversion layer 151 cannot be obtained. Further, as described above, the barrier layer 153 is made of a metal oxide film such as alumina, and the oxygen atoms constituting the metal oxide repel each other electrostatically with the oxygen atoms contained in the acrylic resin. It is presumed that the adhesion to the wavelength conversion layer 151 is weak due to reasons such as mutual contact. In particular, when the barrier layer 153 is formed as a flat (smooth) film on the first support layer 152 by a vacuum deposition method or the like, a so-called anchor effect cannot be expected, and the acrylic resin constituting the wavelength conversion layer 151 However, sufficient adhesion cannot be obtained. Note that the barrier layer 153 is transparent and has excellent light transmittance.

Next, an example of a method for manufacturing the phosphor sheet 150 will be described with reference to FIG. FIG. 4 is an explanatory view showing an example of a method for manufacturing the phosphor sheet 150.

The manufacturing method of the phosphor sheet 150 of the present embodiment includes an application layer forming step (a-1), a bonding step (a-2), and a curing step (a-3).

In the coating layer forming step (a-1), a first support layer 152 made of a polyester resin and a barrier layer 153 made of a metal oxide film are laminated on one surface of the first support layer 152. Among the set of first unit members U1 and U1, a composition in which quantum dot phosphors are dispersed in an ultraviolet curable acrylic resin on the surface of the first support layer 152 in one first unit member U1. In this step, a liquid is applied to form a coating layer 51 made of the applied product.

The first unit member U1 is obtained by forming a barrier layer 153 in advance on a sheet-like (film-like) first support layer 152 made of a polyester-based resin such as PET using a vacuum deposition method or the like. One set of such first unit members U1 is prepared (see 4A in FIG. 4). Among such first unit members U1, in one first unit member U1, a composition liquid for forming the wavelength conversion layer 151 is applied on the surface on the first support layer 152 side (FIG. 4). 4).

The composition liquid is a liquid monomer component constituting an acrylic resin such as acrylic acid or methacrylic acid, a photopolymerization initiator for polymerizing the monomer component, a quantum dot phosphor (green quantum dot phosphor, red quantum dot) Phosphor), a scattering agent, and the like. The method for applying the composition liquid is not particularly limited, and for example, the composition liquid is applied onto the first support layer 153 of the first unit member U1 using a known coater or the like.

The bonding step (a-2) is a step of bonding the other first unit member U1 so that the coating layer 51 is sandwiched between the one first unit member U1 described above. At that time, the other first unit member U1 is attached so that the first support layer 152 made of polyester resin is in contact with the coating layer 51 (see 4C in FIG. 4).

The curing step (a-3) is a step of obtaining the wavelength conversion layer 151 by irradiating the coating layer 51 with ultraviolet UV through the first unit member U1 to cure the coating layer 51. In the present embodiment, the ultraviolet ray UV is applied to the coating layer 51 only from one first unit member U1 side (that is, one side) (see 4C in FIG. 4), but in other embodiments. May be irradiated from both first unit members U1 side (that is, both sides). As described above, when the coating layer 51 is irradiated with ultraviolet rays, the coating layer 51 is cured to become the wavelength conversion layer 151, and the phosphor sheet 150 is obtained.

In the illumination device 12 having the phosphor sheet 150 as described above, when the LED 17 is driven to turn on, the LED 17 emits blue light toward the light incident surface 19 b of the light guide plate 19. Blue light from the LED 17 enters the light guide plate 19 from the light incident surface 19b and propagates while being repeatedly reflected on the back surface 19c of the light guide plate 19 and the front surface (light emitting surface 19a). The light that has jumped out of the back surface 19c of the light guide plate 19 is reflected by the reflection sheet 20 and returned again to the light guide plate 19 side.

The light reflected by the reflection sheet 20 or the dot-like reflection pattern (not shown) formed on the back surface 19b of the light guide plate 19 jumps out from the light emission surface 19a and is supplied to the phosphor sheet 150. . A part of the light (blue light) supplied to the phosphor sheet 150 is converted in wavelength by the wavelength conversion layer 151 of the phosphor sheet 150, and is emitted toward the other optical member 15 as green light or red light. Is done. The other part of the light (blue light) supplied to the phosphor sheet 150 is transmitted without being converted in wavelength by the wavelength conversion layer 151. Note that light that has been wavelength-converted by the phosphor sheet 150 or light that has passed through the phosphor sheet 150 may be supplied to the liquid crystal panel 11 through the other optical member 15 as it is. Is reflected (retroreflected) a plurality of times by a reflective polarizing sheet or the like provided in the optical member 15 and then supplied to the liquid crystal panel 11.

The light supplied from the lighting device 12 to the liquid crystal panel 11 is in a so-called white light state. That is, from the lighting device 12, blue light emitted from the LED 17, green light obtained by wavelength conversion by the phosphor sheet 150, and red light obtained by wavelength conversion by the phosphor sheet 150 are mixed with each other. The combined light is emitted. When such light (white light) from the illuminating device 12 is irradiated toward the liquid crystal panel 11, an image is displayed in a visible state on the panel surface of the liquid crystal panel 11.

As described above, according to the present embodiment, the barrier layer 153 is not directly laminated on the binder resin layer containing the quantum dot phosphor (that is, the wavelength conversion layer 151), but is made of a polyester resin. By forming via the first support layer 152, the wavelength conversion layer 151 can be reliably protected by the barrier layer 153.

<Embodiment 2>
Hereinafter, Embodiment 2 of the present invention will be described with reference to FIGS. 5 and 6. In the following description of each embodiment, the same components as those in the first embodiment described above are denoted by the same reference numerals as those in the first embodiment, and detailed description thereof will be omitted as appropriate.

FIG. 5 is a cross-sectional view schematically showing a part of the configuration of the phosphor sheet 150A according to the second embodiment. As shown in FIG. 5, the phosphor sheet 150 A of the present embodiment has a pair of first support layers 152 formed on both surfaces of the wavelength conversion layer 151 so as to sandwich the wavelength conversion layer 151 and the wavelength conversion layer 151. , 152. In addition, for convenience of explanation, the one in which the pair of first support layers 152 and 152 are attached to the wavelength conversion layer 151 is referred to as a second unit member U2 in this specification.

The phosphor sheet 150A of the present embodiment is obtained by attaching a pair (a set) of third unit members U3 including the barrier layer 153 to both surfaces of the second unit member U2 via the adhesive layer 155, respectively. Become.

The third unit member U3 includes a second support layer 154 and a barrier layer 153 formed on the second support layer 154 using a vacuum deposition method or the like. The 2nd support layer 154 consists of a sheet-like (film form) member which consists of polyester-type resin, such as PET, like the 1st support layer 152 mentioned above. In the case of the present embodiment, one set (a pair) of third unit members U3 is prepared.

The adhesive layer 155 is not particularly limited as long as it is a transparent light-transmitting material that bonds the second unit member U2 and the third unit member U3 to each other, and is appropriately selected from known ones. . Examples of such an adhesive layer 155 include an OCA (Optical Clear Clear) film.

In the phosphor sheet 150A of the present embodiment, the third unit member U3 is adhesive with the barrier layer 153 disposed on the inner side (that is, the second unit member U2 side) with respect to the second unit member U2. Affixed via layer 155. That is, the adhesive layer 155 is interposed between the first support layer 152 of the second unit member U2 and the barrier layer 153 of the third unit member U3, and fixes the first support layer 152 and the barrier layer 153 to each other. To do.

In this way, the barrier layer 153 is not directly formed on the wavelength conversion layer 151, but the third unit member U3 is disposed on the second unit member U2 including the wavelength conversion layer 151 via the adhesive layer 155. You may paste.

The phosphor sheet 150 A of the present embodiment includes many layers as compared with the first embodiment, and light is likely to be multiply reflected, and the light conversion efficiency by the quantum dot phosphor included in the wavelength conversion layer 151 is high. It will be a thing. Therefore, the amount of the quantum dot phosphor blended in the wavelength conversion layer 151 can be reduced as compared with the first embodiment, and the manufacturing cost can be suppressed.

Next, an example of a method for manufacturing the phosphor sheet 150A will be described. FIG. 6 is an explanatory diagram illustrating an example of a method for manufacturing the phosphor sheet 150A according to the second embodiment.

The manufacturing method of the phosphor sheet 150A of the present embodiment includes an adhesive layer forming step (b-1) and a bonding step (b-2).

The adhesive layer forming step (b-1) is a step of forming the

adhesive layers

155 and 155 on both surfaces of the second unit member U2. As described above, the second unit member U2 is a pair of sandwiching the wavelength conversion layer 151 including the acrylic resin, the quantum dot phosphor dispersed in the acrylic resin, and the polyester resin. And the first support layer 152. As shown in 6A of FIG. 6, such a second unit member U2 is prepared in advance.

And the adhesive layer 155 which consists of OCA films is laminated | stacked with respect to such 2nd unit member U2.

The bonding step (b-2) includes a second support layer 154 made of a polyester-based resin and a barrier layer 153 made of a metal oxide film that is laminated on one surface of the second support layer 154. In this step, the pair of third unit members U3 are bonded to the adhesive layer 155 in such a manner that the barrier layer 153 is arranged on the inner side (second unit member U2 side).

As shown in 6C of FIG. 6, in this embodiment, the barrier layer 153 is arranged on the inner side (second unit member U2 side), and one third unit member U3 is bonded to the adhesive layer 155. It is done.

After the third unit member U3 is bonded, the top and bottom of the laminate of the third unit member U3 and the second unit member U2 are inverted, and the other surface of the second unit member U2 (that is, the other first support layer). 152 surface) is subjected to an adhesive layer forming step (b-1). That is, as shown in 6D of FIG. 6, an adhesive layer 155 made of an OCA film is formed on the other surface of the second unit member U2.

Thereafter, the bonding step (b-2) is performed on the adhesive layer 155, and the other third unit member is bonded.

Through the above-described steps, the phosphor sheet 150A of the present embodiment can be manufactured. Such a phosphor sheet 150A may be used in place of the phosphor sheet 150 of the first embodiment.

<Embodiment 3>
Next, a phosphor sheet 150B according to Embodiment 3 of the present invention will be described with reference to FIG. FIG. 7 is a cross-sectional view schematically showing a partial configuration of the phosphor sheet 150B according to the third embodiment.

In the phosphor sheet 150B of the present embodiment, a pair (a set) of third unit members U3 and U3 are bonded to the second unit member U2 via the adhesive layer 155, as in the second embodiment. It consists of things. However, in the case of the present embodiment, the direction of the third unit member U3 when the third unit member U3 is bonded to the second unit member U2 is different. That is, in the case of the present embodiment, the third unit member U3 is bonded to the second unit member U2 so that the barrier layer 153 is disposed on the outside. Therefore, the adhesive layer 155 is interposed between the first support layer 152 of the second unit member U2 and the second support layer 154 of the third unit member U3, and the first support layer 152 and the second support layer 154 are interposed therebetween. Are fixed to each other. In this manner, the upper and lower arrangements of the third unit member U3 may be interchanged and bonded to the second unit member U2.

The phosphor sheet 150B of the present embodiment includes many layers as compared with the first embodiment, and light is likely to be multiply reflected, and the light conversion efficiency by the quantum dot phosphor included in the wavelength conversion layer 151 is high. It will be a thing. Therefore, the amount of the quantum dot phosphor blended in the wavelength conversion layer 151 can be reduced as compared with the first embodiment, and the manufacturing cost can be suppressed.

In addition, the phosphor sheet 150B of the present embodiment is in a state where the position of the barrier layer 153 is further away from the wavelength conversion layer 151 than the second embodiment. Therefore, it can be said that the second embodiment is preferable from the viewpoint of more reliably suppressing moisture, oxygen, and the like entering from the outside.

The manufacturing method of the phosphor sheet 150B of the present embodiment is basically the same as that described above except that it is bonded to the second unit member U2 via the adhesive layer 155 so that the barrier layer 153 is arranged on the outside. This is the same as the manufacturing method of the second embodiment. Such a phosphor sheet 150B may be used in place of the phosphor sheet 150 of the first embodiment.

<Embodiment 4>
Next, Embodiment 4 of the present invention will be described with reference to FIG. FIG. 8 is a cross-sectional view schematically illustrating a schematic configuration of a liquid crystal display device 10C in which the phosphor sheet 150C according to the fourth embodiment is used. As shown in FIG. 8, the liquid crystal display device 10 C of the present embodiment includes a direct-type backlight device (illumination device) 12 C in which the LEDs 17 C are arranged on the back side (directly below) of the liquid crystal panel 11. . Also in the backlight device 12C having such a configuration, the phosphor sheet 150C may be used as a part of the optical member 15C together with the diffusion plate and the like. In addition to the LED 17C that emits blue light and the phosphor sheet 150C that includes the green quantum dot phosphor and the red quantum dot phosphor, the backlight device 12C includes a chassis made of a shallow box as shown in FIG. 14C, a reflection sheet 20C laid on the bottom of the chassis 14, an LED board 18C for mounting the LED 17C, a frame 16C, a bezel 13C, and the like disposed on the bottom side of the chassis 14.

<Other embodiments>
The present invention is not limited to the embodiments described with reference to the above description and drawings. For example, the following embodiments are also included in the technical scope of the present invention.

(1) In the above embodiment, the quantum dot phosphors included in the phosphor sheet are the green quantum dot phosphor and the red quantum dot phosphor. However, the present invention is not limited to this, and is excited by light from the light source. It may be a quantum dot phosphor that emits other colors.

(2) In the above embodiment, an LED emitting blue light is used as a light source. However, the present invention is not limited to this, and an LED emitting another color (excitation light) may be used as a light source.

(3) In the above embodiment, a pair (one set) of barrier layers are used so as to sandwich the wavelength conversion layer 151. However, in other embodiments, two or more sets of barrier layers 153 may be used. For example, a configuration in which a plurality of barrier layers 153 are provided only on one side with respect to the wavelength conversion layer 151 may be employed.

(4) In the above embodiment, the television receiver provided with the tuner is exemplified as the actual device, but the present invention is also applicable to a display device not provided with the tuner. Specifically, the present invention can be applied to a liquid crystal display device used as an electronic signboard (digital signage) or an electronic blackboard.

(5) In the above embodiment, the liquid crystal display device using the liquid crystal panel as the display panel has been exemplified. However, the present invention is not limited to this, and the display device using another type of display panel (for example, a Colton signboard) is used. The present invention is also applicable.

(6) In the above embodiment, the LED is used as the light source. However, the present invention is not limited to this, and other light sources such as an organic EL may be used.

DESCRIPTION OF SYMBOLS 10 ... Liquid crystal display device (display device), 11 ... Liquid crystal panel, 12 ... Backlight device (illuminating device), 13 ... Bezel, 14 ... Chassis, 15 ... Optical member, 150 ... phosphor sheet (an example of an optical member), 151 ... wavelength conversion layer, 152 ... first support layer, 153 ... barrier layer, 154 ... second support layer, 155 ... Adhesive layer, 16 ... frame, 17 ... LED (light source), 18 ... LED substrate, 19 ... light guide plate, 20 ... reflection sheet, U1 ... first unit member, U2 ... second unit member, U3 ... third unit member

Claims

A wavelength conversion layer comprising an acrylic resin and a quantum dot phosphor dispersed in the acrylic resin;
A pair of first support layers made of a polyester resin and sandwiching the wavelength conversion layer;
An optical member including a pair of barrier layers made of a metal oxide film, disposed on the outer side of the first support layer, and sandwiching at least the wavelength conversion layer via the first support layer.
The optical member according to claim 1, wherein the barrier layer is laminated on the first support layer.
Made of polyester resin, the barrier layer is laminated, and the barrier layer is arranged on the inner side, or the barrier layer is arranged on the outer side, and arranged on the outer side than the first support layer. A pair of second support layers;
When the barrier layer is disposed inside, the first support layer and the second support layer are interposed between the first support layer and the barrier layer, and when the barrier layer is disposed outside, The optical member according to claim 1, further comprising a pair of adhesive layers interposed between the optical members.
The optical member according to any one of claims 1 to 3, wherein the barrier layer is formed by physical vapor deposition or chemical vapor deposition.
The optical member according to any one of claims 1 to 4, wherein the quantum dot phosphor includes at least a green quantum dot phosphor that emits light in a green wavelength region.
The optical member according to any one of claims 1 to 5, wherein the quantum dot phosphor includes at least a red quantum dot phosphor that emits light in a red wavelength region.
The optical member according to any one of claims 1 to 6, wherein the wavelength conversion layer includes a scattering agent.
An illumination device comprising: the optical member according to any one of claims 1 to 7; and a light source that emits excitation light that excites the quantum dot phosphor included in the wavelength conversion layer.
A display device comprising: the illumination device according to claim 8; and a display panel that displays an image using light supplied from the illumination device.
The display device according to claim 9, wherein the display panel is a liquid crystal panel.
A television receiver comprising the display device according to claim 9 or 10.
One set of first unit members including a first support layer made of a polyester-based resin and a barrier layer made of a metal oxide film and laminated on one surface of the first support layer. On the surface of the first support layer in one unit member, a coating layer in which a quantum dot phosphor is dispersed in an ultraviolet curable acrylic resin is coated to form a coating layer made of the coating material. Forming process;
A bonding step of bonding the other first unit member so as to sandwich the coating layer between the one first unit member;
An optical member manufacturing method comprising: a curing step of irradiating ultraviolet rays toward the coating layer through the first unit to cure the coating layer to obtain a wavelength conversion layer.
Both surfaces of a second unit member having an acrylic resin and a wavelength conversion layer containing a quantum dot phosphor dispersed in the acrylic resin, and a pair of first support layers made of a polyester resin and sandwiching the wavelength conversion layer Forming an adhesive layer on the adhesive layer forming step;
A pair of third unit members having a second support layer made of a polyester-based resin and a barrier layer made of a metal oxide film laminated on one surface of the second support layer, An optical member manufacturing method comprising: a bonding step of bonding to the adhesive layer in a form arranged on the inside or in a form in which the barrier layer is arranged on the outside.
The method for manufacturing an optical member according to claim 13, wherein in the adhesive layer forming step, the adhesive layer is made of an OCA film.
The method for manufacturing an optical member according to any one of claims 12 to 14, wherein the barrier layer is formed by a physical vapor deposition method or a chemical vapor deposition method.