WO2016186158A1

WO2016186158A1 - Lighting device and display device

Info

Publication number: WO2016186158A1
Application number: PCT/JP2016/064843
Authority: WO
Inventors: 田中　正太郎; 隆一若原; 裕介塚村
Original assignee: 東レ株式会社
Priority date: 2015-05-20
Filing date: 2016-05-19
Publication date: 2016-11-24
Also published as: KR20180008436A; CN107533257B; KR102538377B1; JP6787127B2; JPWO2016186158A1; CN107533257A

Abstract

A lighting device which is provided with a light wavelength conversion sheet, a light wavelength selection filter and a light emitting element, and which is characterized in that: the light emitting element, the light wavelength conversion sheet and the light wavelength selection filter are arranged therein in this order; the area of the light wavelength selection filter is smaller than the area of the light wavelength conversion sheet; and the light emitting element is arranged at a distance from the light wavelength conversion sheet. Provided are: a lighting device which is suppressed in color unevenness by improving the problem of color difference between the color near the central part and the color near the edge part of the lighting device; and a display device which uses this lighting device.

Description

Lighting device and display device

The present invention relates to an illumination device used for, for example, a liquid crystal display and a display device using the same.

A lighting device used for a liquid crystal display or the like is a lighting device for expressing a high-efficiency and pure color. A light emitting element such as a blue LED or a blue laser is used as a light source, and a film containing quantum dots or phosphors is further used. An illuminating device that performs color adjustment using it is used (Patent Document 1).

In this illumination device, blue light is emitted from a light emitting element such as a blue LED or a blue laser toward a film containing quantum dots and phosphors, and the emitted blue light is converted into green light and red light with quantum dots and phosphors. Change the color. Then, the blue light of the light emitting element is combined with the green light and the red light that are color-converted with the quantum dots and the phosphor to obtain white light.

Special table 2013-544018 gazette

In the illumination device used for the liquid crystal display as described above, that is, the illumination device that obtains white light using a light emitting element such as a blue LED or a blue laser, and a film containing quantum dots or phosphors, the central portion of the illumination device The color near the edge of the lighting device (display color near the edge of the screen in the case of a liquid crystal display) is lighter than the color near it (display color near the center of the screen if it is a liquid crystal display) There is a problem that the influence of the luminescent color of the light becomes strong (if the light emitting element is a blue LED or a blue laser, the color becomes bluish).

An object of the present invention is to improve the problem that the color near the center of the lighting device is different from the color near the end, and to provide a lighting device with little color unevenness and a display device using the same.

The above object of the present invention has been basically achieved by the following invention.

[1] a light wavelength conversion sheet;
An optical wavelength selection filter;
A light emitting element;
A lighting device comprising:
A light emitting element, a light wavelength conversion sheet, and a light wavelength selection filter are provided in this order,
The area of the light wavelength selection filter is smaller than the area of the light wavelength conversion sheet,
The illuminating device, wherein the light emitting element is separated from the light wavelength conversion sheet.

[2] a light wavelength conversion sheet;
An optical wavelength selection filter;
A light emitting element;
A lighting device comprising:
A light emitting element, an optical wavelength selection filter, and an optical wavelength conversion sheet are provided in this order.
The area of the light wavelength selection filter is smaller than the area of the light wavelength conversion sheet,
The illuminating device, wherein the light emitting element is separated from the light wavelength conversion sheet.

[3] a first light wavelength conversion sheet;
A second light wavelength conversion sheet;
A light emitting element;
A lighting device comprising:
The first light wavelength conversion sheet, the light emitting element, and the second light wavelength conversion sheet are provided in this order,
The area of the first light wavelength conversion sheet is smaller than the area of the second light wavelength conversion sheet,
The illuminating device, wherein the light emitting element is provided apart from the second light wavelength conversion sheet.

[4] The illumination device according to [1] or [2], wherein the optical wavelength selection filter satisfies the following formula (1).

| λ2-λ3 | ≦ 50 (where λ1 <λ2, λ1 <λ3) (1)
λ1: Light emission wavelength of light emitting element (nm)
λ2: wavelength at which the transmittance of the optical wavelength selection filter becomes 70% (nm)
λ3: wavelength (nm) at which the transmittance of the optical wavelength selection filter is 30%.

[5] The illumination device according to any one of [1] to [3], wherein a surface of the light wavelength selection filter and / or the light wavelength conversion sheet has an uneven shape.

[6] The illumination device according to [1] or [2], wherein a plurality of the light emitting elements are provided corresponding to the entire surface of the light wavelength conversion sheet.

[7] The illumination device according to [3], wherein a plurality of the light emitting elements are provided corresponding to the entire surface of the second light wavelength conversion sheet.

[8] The method according to [1] or [2], further comprising a light guide plate disposed in an optical path from the light emitting element to the light wavelength conversion sheet for light emitted from the light emitting element. Lighting device.

[9] The illumination device according to [3], further comprising a light guide plate disposed in an optical path from the light emitting element to the second light wavelength conversion sheet for light emitted from the light emitting element. .

[10] The illumination device according to [8] or [9], wherein a plurality of the light emitting elements are provided along an end portion of the light guide plate.

[11] A brightness enhancement film is further included, and the brightness enhancement film is provided on the emission side of any member of the light emitting element, the light wavelength sheet, and the light wavelength selection filter. [3] The illumination device according to any one of [3].

[12] The angle between the direction in which the transmittance at the wavelength λ3 of the optical wavelength selection filter is maximized and the direction in which the transmittance at the wavelength λ3 of the brightness enhancement film is maximized is 10 ° or less. The lighting device according to [11].

[13] The angle between the direction in which the transmittance at the wavelength λ3 of the optical wavelength selection filter is maximized and the direction in which the transmittance at the wavelength λ3 of the brightness enhancement film is maximized is 80 ° or more. The lighting device according to [11].

[14] A specular reflective film is further included, and the specular reflective film is provided on the opposite side of the light-emitting element, light wavelength sheet, and light wavelength selection filter from the emission side. The illumination device according to any one of [1] to [3].

[15] A display device comprising a display panel and a lighting device provided adjacent to the display panel,
The lighting device is
[1] A display device comprising the illumination device according to any one of [14].

According to the present invention, an illumination device with little color unevenness can be obtained, and if it is used for a display device, a display device with excellent display performance with little color unevenness can be obtained.

It is the schematic of an example of an illuminating device. It is the schematic of an example of a display apparatus. It is a schematic diagram in 1st Embodiment of the illuminating device of this invention. It is an example of the 1st wavelength and the 2nd wavelength. It is an optical path when there is no optical wavelength selection filter in the first embodiment. It is an optical path in case there exists an optical wavelength selection filter in 1st Embodiment. It is an example of the optical wavelength selection filter and optical wavelength conversion sheet | seat in 1st Embodiment. It is a schematic diagram in 2nd Embodiment of the illuminating device of this invention. It is a schematic diagram in 3rd Embodiment of the illuminating device of this invention. It is an optical path in case there is no optical wavelength selection filter in 3rd Embodiment. It is an optical path in case there exists an optical wavelength selection filter in 3rd Embodiment. It is an example of the optical wavelength selection filter and optical wavelength conversion sheet in 3rd Embodiment. It is a schematic diagram in 4th Embodiment of the illuminating device of this invention. It is a schematic diagram in 5th Embodiment of the illuminating device of this invention. It is an optical path when there is no 1st light wavelength conversion sheet in 5th Embodiment. It is an optical path in case there exists the 1st light wavelength conversion sheet in 5th Embodiment. It is an example of the 1st light wavelength conversion sheet and reflector in 5th Embodiment. It is a schematic diagram in 6th Embodiment of the illuminating device of this invention. It is a simplified diagram of the lighting device A. It is an xy chromaticity diagram.

Hereinafter, embodiments of the present invention will be described.

FIG. 1A is a schematic cross-sectional view of an example of the illumination device of the present invention, and FIG. 1B is a schematic plan view of a substrate, an LED, and a reflector. FIG. 2 is a schematic cross-sectional view when a liquid crystal display is used as a display device, for example. Examples of the liquid crystal display include, but are not limited to, a TV, a monitor, a notebook personal computer, a tablet portable terminal, and a smartphone. In addition to the liquid crystal display, the lighting device can be used for display devices such as signboards and vending machines, and can also be suitably used as various lighting devices such as household lighting devices and facility lighting devices. It is not limited to these. As the optical film of FIGS. 1 and 2, a diffusion film, a prism film, a retroreflective film, or the like is used.

The light wavelength conversion sheet is a sheet that converts light of a specific wavelength into light of another wavelength. In the present invention, a light wavelength conversion sheet that converts light having a specific wavelength (light having a first wavelength) into light having another wavelength (light having a second wavelength) is preferably used.

Here, converting light of a specific wavelength into light of another wavelength means that light having a peak at a specific wavelength (light of the first wavelength) has light at a wavelength other than the specific wavelength (first 2). The light having the second wavelength may be light having a peak at one wavelength, or light having a peak at each of the two wavelengths. That is, the light of the first wavelength is converted by the light wavelength conversion sheet into light of the second wavelength having a peak at one wavelength (second wavelength) different from the peak wavelength of the light of the first wavelength. Alternatively, the light may be converted into two lights, light having a peak at the second wavelength α and light having a peak at the second wavelength β.

The light of the first wavelength is preferably light having a wavelength having a peak at 200 nm to less than 380 nm (near ultraviolet) and / or light having a wavelength having a peak at 380 nm to less than 495 nm (blue). More preferably, it is light having a wavelength having a peak at 220 nm or more and 350 nm or less and / or light having a wavelength having a peak at 400 nm or more and 470 nm or less, more preferably light having a wavelength having a peak at 240 nm or more and 320 nm or less and / or 410 nm or more. It is light having a wavelength having a peak at 460 nm or less. Examples of light emitting elements that emit light of these wavelengths include near ultraviolet LEDs and blue LEDs. In addition, as light having the second wavelength, light having a wavelength having a peak at 495 nm to less than 570 nm (green), light having a wavelength having a peak at 570 nm to less than 590 nm (yellow), and a peak having a peak at 590 nm to 750 nm (red) It is preferable that the light is at least one wavelength selected from the group consisting of light having a wavelength. More preferably, at least one wavelength selected from the group consisting of light with a wavelength having a peak at 510 nm to 565 nm and below, light having a wavelength at 575 nm to 590 nm and light having a peak at 600 nm to 700 nm. More preferably, the light is selected from the group consisting of light having a wavelength having a peak at 520 nm to 555 nm and light having a wavelength having a peak at 580 nm to 590 nm and light having a peak at 610 nm to 680 nm. Light of at least one wavelength.

Also, the optical wavelength selection filter is a filter that transmits or reflects light of a specific wavelength.

Here, the area of the light wavelength selection filter is preferably smaller than the area of the light wavelength conversion sheet. If the area of the light wavelength selection filter is made smaller than the area of the light wavelength conversion sheet and is partially disposed in the illumination device, it is preferable because the color of the emitted light of the illumination device can be partially adjusted.

Note that a light-emitting element refers to a semiconductor element that emits light. The light emitting element may be provided in any way in the lighting device. For example, when the light emitting element is provided on the substrate, it is preferable that a plurality of light emitting elements are provided corresponding to the entire surface of the light wavelength conversion sheet from the viewpoint of efficiently emitting light. When using a light guide plate described later, it is preferable that a plurality of light guide plates are provided along the end of the light guide plate from the viewpoint of light emission efficiency.

(First embodiment)
The first embodiment, which is an example of the illumination device of the present invention, will be described with reference to FIGS.

FIG. 3 is a schematic diagram in the first embodiment of the illumination device of the present invention. A light wavelength conversion sheet 31 and a light wavelength selection filter 32 are provided, and a blue LED 33 is provided on the substrate 34 as a light emitting element. In addition, a reflecting plate 37 and a diffusing plate 38 are provided to reflect and diffuse light from the light emitting element.

Blue LED 33, light wavelength conversion sheet 31, and light wavelength selection filter 32 are provided in this order.

The blue LED 33 is provided apart from the light wavelength conversion sheet 31 and emits light toward the light wavelength conversion sheet 31.

The area of the light wavelength selection filter 32 is preferably smaller than the area of the light wavelength conversion sheet 31. If the area of the light wavelength selection filter 32 is made smaller than the area of the light wavelength conversion sheet 31 and is partially disposed in the illumination device, it is preferable because the color of the emitted light of the illumination device can be partially adjusted efficiently.

In the first embodiment, the optical wavelength selection filter 32 reflects the first wavelength light emitted from the blue LED 33, and the second wavelength generated by the light wavelength conversion sheet 31 converting the first wavelength light. It transmits light of a wavelength.

The light wavelength selection filter 32 in the first embodiment has a peak wavelength (hereinafter sometimes referred to as a peak wavelength of the second wavelength) for the light of the second wavelength converted by the light wavelength conversion sheet 31. Is a filter that reflects at least 85% of light having a peak wavelength (hereinafter also referred to as peak wavelength of the first wavelength) with respect to light having the first wavelength. That is, the filter has a transmittance of 85% or more at the peak wavelength of the second wavelength and a reflectance of 20% or more at the peak wavelength of the first wavelength. In addition, when there are two or more light beams having the second wavelength, it means a filter having a transmittance of 85% or more for all the light beams having the second wavelength.

The light of the first wavelength is light having a peak at a specific wavelength, and the light of the second wavelength is light having a peak at a wavelength different from the light of the first wavelength.

FIG. 4 is an example of the first wavelength and the second wavelength. In the example of the wavelength in FIG. 2, the light emitting element is a blue LED, and the light wavelength conversion sheet converts the blue light of the blue wavelength, which is the first wavelength emitted from the blue LED, to the green that is the second wavelength. Two types of quantum dots are included: a green quantum dot that emits green light of a wavelength, and a red quantum dot that emits red light that is red wavelength, which is the second wavelength, by converting blue light. This is an example. The blue LED has a blue light peak of 450 nm, a green light peak of 550 nm, and a red light peak of 610 nm. By combining these lights, white light can be obtained.

5 and 6 are diagrams showing optical paths when there is no optical wavelength selection filter 32 and when there is no optical wavelength selection filter 32, respectively.

As shown in FIG. 6, the light wavelength selection filter 32 transmits green light and red light converted by the light wavelength conversion sheet, and reflects a part or all of the blue light emitted by the blue LED. Here, reflecting part of the blue light emitted by the blue LED means that the reflectance at the peak wavelength of the blue light emitted by the blue LED is 20% or more, and the blue light emitted by the blue LED is emitted. The reflection of all of the above means that the reflectance at the peak wavelength of the blue light emitted by the blue LED is 100% or more.

Therefore, the bluishness of the light emitted to the emission surface side of the light wavelength selection filter 32 is reduced as compared with the light emitted to the emission surface side in the case of FIG. 5, that is, when there is no light wavelength selection filter 32.

In accordance with this principle, the light wavelength selection filter 32 is partially disposed in a portion with strong bluishness (a portion where the influence of the light emission color of the light emitting element is strong) such as near the end of the lighting device, so that the color unevenness of the lighting device can be obtained. Can be improved.

Note that the blue light reflected by the light wavelength selection filter 32 is reused in the lighting device by being reflected by a reflector or the like, so that there is little light loss. Accordingly, color adjustment can be performed with less light loss compared to other color adjustment methods that reduce blueness by the principle of absorbing blue light.

The optical wavelength selection filter 32 preferably has a reflectance of 20% or more at the peak wavelength of the first wavelength. On the other hand, if the reflectance is too high, color unevenness may occur due to an excessive blue reduction effect. Therefore, the reflectance at the peak wavelength of the first wavelength is more preferably 25 to 90%. More preferably 30 to 80%.

The light wavelength selection filter 32 preferably has a transmittance of the peak wavelength of the second wavelength of 85% or more, more preferably 87% or more, and further preferably 90% or more.

The light wavelength selection filter 32 may be laminated on the light wavelength conversion sheet 31, for example, as shown in FIG.

It is also preferable that the optical wavelength selection filter 32 satisfies the following formula (1). The following formula (1) indicates that the change in transmittance between the wavelength band that reflects light and the wavelength band that transmits light is steep, and as | λ2−λ3 | It changes from a reflected wavelength band to a transmitted wavelength band. Blue light is converted by the light wavelength conversion sheet from the wavelength band that is transmitted from the reflected wavelength band, that is, the wavelength band that reflects the blue light emitted by the blue LED in the first embodiment. By changing sharply to the wavelength band that transmits green light of the green wavelength that is the emission wavelength, it is possible to transmit green light while selectively reflecting only blue light selectively and efficiently, and light wavelength selection This makes it easier to obtain the maximum filter effect.

The optical wavelength selection filter is preferably a laminate of two types of films having different refractive indexes that are transparent in the visible light region. By laminating two types of films having different refractive indexes, light is reflected at the interface between the films, and the wavelength of the reflected light is adjusted by adjusting the difference in refractive index between the two types of films and the thickness of each film. Can be selected. Further, the reflectance can be adjusted by adjusting the number of the two types of films stacked alternately.

The two types of films may be organic resin materials or inorganic materials, and the organic resin may be either a thermoplastic resin or a curable resin. Further, it may be a homo resin, a copolymer resin or a blend of two or more kinds of resins. More preferably, it is a thermoplastic resin because of good moldability. In each resin, various additives such as antioxidants, antistatic agents, crystal nucleating agents, inorganic particles, organic particles, viscosity reducers, thermal stabilizers, lubricants, infrared absorbers, ultraviolet absorbers, A dopant for adjusting the refractive index may be added.

When a blue LED is used, it is also preferable that a fluorescent whitening agent is included in the light wavelength selection filter. The fluorescent whitening agent is one that emits blue light when excited by light having a wavelength shorter than the emission wavelength of the blue LED. The fluorescent whitening agent is emitted from the LED by including the fluorescent whitening agent. Light of a short wavelength that cannot be converted can be converted into blue light that can be converted into green light or red light by a light wavelength conversion sheet, and brightness can be improved when the lighting device is formed.

Examples of thermoplastic resins include polyolefin resins such as polyethylene, polypropylene, polystyrene and polymethylpentene, alicyclic polyolefin resins, polyamide resins such as nylon 6 and nylon 66, aramid resins, polyethylene terephthalate, polybutylene terephthalate and polypropylene terephthalate. Polyester resin such as polybutyl succinate, polyethylene-2,6-naphthalate, polycarbonate resin, polyarylate resin, polyacetal resin, polyphenylene sulfide resin, tetrafluoroethylene resin, trifluorinated ethylene resin, trifluorinated ethylene chloride resin Fluorine resin such as ethylene tetrafluoride-6-propylene copolymer, vinylidene fluoride resin, acrylic resin such as PMMA, methacrylic resin, poly Acetal resin, polyglycolic acid resin, polylactic acid resin, acrylonitrile-butadiene-styrene copolymer, acrylonitrile-ethylene - propylene rubber, or the like can be used styrene copolymer. Among these, a polyester resin is particularly preferable from the viewpoint of strength, heat resistance, and transparency.

Among polyester resins, polyethylene terephthalate and copolymers thereof, polyethylene naphthalate and copolymers thereof, polybutylene terephthalate and copolymers thereof, polybutylene naphthalate and copolymers thereof, and polyhexamethylene terephthalate and copolymers thereof. It is preferable to use a polymer, polyhexamethylene naphthalate, and a copolymer thereof.

In order to obtain an optical wavelength selective filter that satisfies the above formula (1), it is also preferable to use a laminated film made of a thermoplastic resin. In this case, although the number of layers tends to increase, by controlling the thickness of a large number of layers, it becomes easy to sharpen the change from the wavelength band, in particular from the reflected wavelength band to the transmitted wavelength band.

The shape of the optical wavelength selection filter may be a planar shape, a shape having a large number of holes in the surface, a mesh shape, a circle, an ellipse, a shape surrounded by other curves, a triangle, a rectangle, other Various shapes such as a polygon may be used.

The optical wavelength selection filter in which two kinds of films having different refractive indexes as described above are stacked can be used by stacking on another sheet. The shape of the optical wavelength selection filter when laminating to another sheet may be a planar shape, a shape having a large number of holes on the surface, a mesh shape, or a layered state such as a dot shape. Various shapes such as a circle, an ellipse, a shape surrounded by other curves, a triangle, a quadrangle, and other polygons may be used.

It is also preferable that the surface of the light wavelength selection filter and / or the light wavelength conversion sheet has an uneven shape. Having an uneven shape here means that Rz in JIS B0601 (2001) is 1 μm or more when the surface roughness of the light wavelength selection filter and / or the light wavelength conversion sheet is measured. More preferably, Rz is 10 μm or more, and the following effects can be easily obtained.

The first effect of the surface of the light wavelength selection filter and / or the light wavelength conversion sheet having an uneven shape is easy slipping. Since the surface has a concavo-convex shape, the slipperiness is expressed, so that it is possible to suppress the occurrence of scratches when the light wavelength selection filter and / or the light wavelength conversion sheet is incorporated into the lighting device.

The second effect is light extraction. The inventors of the present invention have found a phenomenon that in the light wavelength conversion sheet, a phenomenon that light is reflected in the light wavelength conversion sheet causes a phenomenon that the light is confined in the sheet like an optical fiber and the luminance is lowered. As a countermeasure, because the surface of the light wavelength selection filter and / or the light wavelength conversion sheet has a concavo-convex shape, light is extracted from the concavo-convex interface, thereby reducing the light taken into the light wavelength conversion sheet and improving the brightness. The effect of is obtained.

The third effect is the adjustment of the optical path of light. The light from the light emitting element, particularly the light emitting diode, travels with a relatively high directivity to the display side, whereas the light from the light wavelength conversion sheet emits isotropically. It will cause a drop. Since the surface of the light wavelength selection filter and / or the light wavelength conversion sheet has a concavo-convex shape, it is easy to adjust the direction of light at the concavo-convex interface, and in particular, to improve brightness by condensing in the front direction. In addition, other optical members can be omitted when forming the lighting device and the display device, which contributes to cost reduction.

In order to obtain the second and third effects more efficiently, the uneven shape is preferably a microlens shape, a prism shape, a substantially triangular shape, or a substantially semicircular shape. The microlens shape indicates a substantially hemispherical unevenness, and the prism shape indicates a substantially triangular unevenness. In the case of having such a shape, since the light path is focused on the display side, the front luminance in the case of the illumination device and the display device is more significantly improved.

As described above, a light-emitting element is a semiconductor element that emits light, and any suitable light-emitting element such as an LED or a laser having a blue or near-ultraviolet wavelength can be used as the light-emitting element.

The light wavelength conversion sheet is a sheet that converts light of a specific wavelength into light of another wavelength as described above. For example, the light wavelength conversion sheet is a sheet containing quantum dots or phosphors having a function of converting a light wavelength. A resin sheet containing quantum dots or phosphors may be used, or a film containing quantum dots or phosphors may be laminated on a sheet serving as a substrate.

When using a light wavelength conversion sheet in which a film containing quantum dots or phosphors is laminated on a sheet serving as a base material, the area of the light wavelength selection filter is the area of the film containing quantum dots or phosphors. It is preferable to make it smaller. If the area of the light wavelength selection filter is made smaller than the area of the film containing quantum dots and phosphors and is partially disposed in the illumination device, the color of the emitted light of the illumination device can be partially adjusted efficiently. Therefore, it is preferable.

As a combination for obtaining white light using a light emitting element and a light wavelength conversion sheet, for example, when a blue LED is used, blue light having a blue wavelength, which is the first wavelength emitted from the blue LED, is converted to the second light. You may use the light wavelength conversion sheet containing the quantum dot for yellow which light-emits the yellow light of the yellow wavelength which is this wavelength. When using a near-ultraviolet LED, red quantum dots that emit light of a red wavelength that is a second wavelength by converting light of a near-ultraviolet wavelength that is the first wavelength emitted from the near-ultraviolet LED; Green quantum dots that emit green light having a green wavelength, which is a second wavelength by converting light having a near ultraviolet wavelength, and blue light having a blue wavelength, which is a second wavelength, by converting light having a near ultraviolet wavelength You may use what contains the quantum dot for blue to light-emit.

Examples of quantum dots include CdSe having a ZnS shell. Alternatively, a core / shell luminescent nanocrystal containing CdSe / ZnS, InP / ZnS, PbSe / PbS, CdSe / CdS, CdTe / CdS, or CdTe / ZnS may be used.

Examples of the phosphor include SrGa ₂ S ₄ : Eu ²⁺ as a green phosphor and (Ca, Sr, Ba) S: Eu ²⁺ as a red phosphor. In the description of the phosphor material, a parenthesis is shown before: and an activator is shown after.

Further, although white light is obtained in the present embodiment, it is possible to appropriately select the type of light emitting element or phosphor in order to obtain light of a desired color as light emitted from the illumination device.

In the first embodiment as well, it is preferable that an optical sheet is provided on the light exit side of the optical wavelength selection filter, as in FIGS. It is preferable to be provided. Prism sheets, microlenses, and polarizing / reflecting films have traditionally been beneficially used to improve frontal brightness, but when used in combination with a light wavelength conversion sheet, the light once transmitted through the light wavelength conversion sheet is used. It can be reflected on the optical film and reflected / re-wavelength converted to the light wavelength conversion sheet side, and the cost can be reduced by reducing the amount of expensive quantum dots used.

As a more preferable combination, the angle between the direction in which the transmittance at the wavelength λ3 of the optical wavelength selection filter is maximized and the direction in which the transmittance at the wavelength λ3 of the brightness enhancement film is maximized is arranged to be 80 ° or more. Can be mentioned. The direction in which the transmittance is maximum here is a direction in which polarized light having a wavelength λ3 is incident perpendicularly to the film surface and the polarization surface is rotated by 5 ° to maximize the transmittance. As the direction in which the transmittance of the light wavelength selection filter and the brightness enhancement film becomes maximum is orthogonal, the polarization that could not be reflected by the light wavelength selection filter can be efficiently reflected by the brightness enhancement film. It is possible to further improve the effect.

As the reflection plate 37, a light diffusive reflection film such as a white film may be used, but a regular reflection film is more preferable. Here, the specular reflectivity means that the glossiness measured at an incident angle of 60 ° and an outgoing angle of 60 ° is 100 or more as per JIS Z8741 (1997). By using a specular reflective film, it becomes possible to reflect light with high efficiency while suppressing scattering of light reflected by the light selective wavelength filter and light that is converted and emitted by the light wavelength conversion sheet. An effect of suppressing color unevenness of the lighting device can be obtained.

(Second Embodiment)
FIG. 8 is a schematic diagram of the lighting apparatus according to the second embodiment of the present invention. A light wavelength conversion sheet 81 and a light wavelength selection filter 82 are provided, and a blue LED 83 is provided as a light emitting element at an end of the light guide plate 85.

Blue LED 83, light wavelength conversion sheet 81, and light wavelength selection filter 82 are provided in this order.

Blue LED 83 is provided apart from light wavelength conversion sheet 81. The light of the blue LED 83 enters from the end of the light guide plate 85 and is emitted while being guided by the light guide plate. Based on this principle, light is emitted toward the light wavelength conversion sheet 81.

The area of the light wavelength selection filter 82 is preferably smaller than the area of the light wavelength conversion sheet 81. If the area of the light wavelength selection filter 82 is made smaller than the area of the light wavelength conversion sheet 81 and is partially disposed in the illumination device, it is preferable because the color of the emitted light from the illumination device can be partially adjusted efficiently.

Other aspects in the second embodiment are the same as those in the first embodiment.

(Third embodiment)
A third embodiment, which is an example of the illumination device of the present invention, will be described with reference to FIGS.

FIG. 9 is a schematic diagram in the third embodiment of the illumination device of the present invention. A light wavelength conversion sheet 91 and a light wavelength selection filter 92 are provided, and a blue LED 93 is provided on the substrate 94 as a light emitting element. Further, a reflecting plate 97 and a diffusing plate 98 are provided in order to reflect and diffuse light from the light emitting element.

Blue LED 93, light wavelength selection filter 92, and light wavelength conversion sheet 91 are provided in this order.

The blue LED 93 is spaced apart from the light wavelength conversion sheet 91 and emits light toward the light wavelength conversion sheet 91.

The area of the light wavelength selection filter 92 is preferably smaller than the area of the light wavelength conversion sheet 91. If the area of the light wavelength selection filter 92 is made smaller than the area of the light wavelength conversion sheet 91 and is partially disposed in the illumination device, it is preferable because the color of the emitted light from the illumination device can be partially adjusted efficiently.

In the third embodiment, the light wavelength selection filter 92 transmits the first wavelength light emitted from the blue LED 93, and the second wavelength generated by the light wavelength conversion sheet 91 converting the first wavelength light. It reflects light of a wavelength.

The optical wavelength selection filter 92 according to the third embodiment transmits 85% or more of the peak wavelength of light emitted from the blue LED 93 (hereinafter sometimes referred to as the peak wavelength of the first wavelength). And a filter that reflects 20% or more of light having a peak wavelength (hereinafter sometimes referred to as a peak wavelength of the second wavelength) with respect to the light having the second wavelength generated by being converted by the light wavelength conversion sheet 91. That means. That is, the filter has a transmittance of 85% or more at the peak wavelength of the first wavelength and a reflectance of 20% or more at the peak wavelength of the second wavelength. In addition, when there are two or more light beams having the second wavelength, it means a filter having a reflectance of 20% or more for all the light beams having the second wavelength.

FIGS. 10 and 11 are diagrams showing optical paths when there is no optical wavelength selection filter 92 and when there is no optical wavelength selection filter 92, respectively.

As shown in FIG. 10, when there is no light wavelength selection filter 92, the light emitted to the opposite side of the emission surface among the green light and red light emitted from the light wavelength conversion sheet diffuses in the illumination device. To do.

As shown in FIG. 11, the light wavelength selection filter 92 transmits the blue light emitted from the blue LED, and is emitted to the opposite side of the emission surface side among the green light and red light emitted from the light wavelength conversion sheet. A part or all of the light is reflected, and the green light and the red light are emitted to the vicinity of the light exit surface provided with the light wavelength selection filter. Therefore, the bluishness of the light emitted toward the emission surface in the vicinity of the light wavelength selection filter 92 is reduced as compared with the light emitted toward the emission surface in the case of FIG. 10, that is, when there is no light wavelength selection filter 92. The

Based on this principle, the light wavelength selection filter 92 is partially disposed in a portion with a strong bluish color (a portion where the influence of the light emission color of the light emitting element is strong) such as near the end of the lighting device, so that the color unevenness of the lighting device can be obtained. Can be improved.

If the light wavelength selection filter 92 is used, color adjustment can be performed with less light loss compared to other color adjustment methods that reduce blueness by the principle of absorbing blue light.

The light wavelength selection filter 92 preferably has a transmittance at the peak wavelength of the first wavelength of 85% or more, more preferably 87% or more, and further preferably 90% or more.

The optical wavelength selection filter 92 preferably has a reflectance at the peak wavelength of the second wavelength of 20% or more, more preferably 30% or more, further preferably 70% or more, and 90% or more. It is particularly preferred that

It is also preferable that the optical wavelength selection filter 92 satisfies the following formula (1). The following formula (1) indicates that the change in transmittance between the wavelength band that reflects light and the wavelength band that transmits light is steep, and as | λ2−λ3 | It changes from a reflected wavelength band to a transmitted wavelength band. In this way, blue light is converted by the light wavelength conversion sheet from the wavelength band that transmits from the reflected wavelength band, that is, the wavelength band that transmits the blue light emitted by the blue LED in the third embodiment. By changing sharply to the wavelength band that reflects green light of the green wavelength that is the emission wavelength, it is possible to reflect green light and red light while selectively and efficiently transmitting only blue light, This makes it easier to obtain the effect of the optical wavelength selection filter to the maximum extent.

The light wavelength selection filter 92 may be laminated on a light wavelength conversion sheet 91 as shown in FIG.

Also in the third embodiment, it is preferable that an optical sheet is provided on the light exit side of the optical wavelength selection filter as in FIGS. 1 and 2, but in particular, a brightness enhancement film such as a prism sheet, a microlens sheet, or a polarizing reflection film is used. When provided, the angle between the direction in which the transmittance at the wavelength λ3 of the optical wavelength selection filter is maximized and the direction in which the transmittance at the wavelength λ3 of the brightness enhancement film is maximized is 10 ° or less. It is preferred that The light wavelength selection filter and the brightness enhancement film are parallel to each other in the direction in which the transmittance is maximum, so that the light reflected from the brightness enhancement film to the light wavelength conversion sheet and the light wavelength selection filter can be efficiently reflected. It is possible to suppress the reflection and reflection to the light emitting element, and the effect of suppressing the color unevenness of the lighting device can be obtained.

Other aspects in the third embodiment are the same as in the first embodiment.

(Fourth embodiment)
FIG. 13 is a schematic diagram of the illumination device according to the fourth embodiment of the present invention. A light wavelength conversion sheet 131 and a light wavelength selection filter 132 are provided, and a blue LED 133 is provided as a light emitting element at an end of the light guide plate 135.

Blue LED 133, light wavelength selection filter 132, and light wavelength conversion sheet 131 are provided in this order.

The blue LED 133 is provided apart from the light wavelength conversion sheet 131. The light of the blue LED 133 enters from the end of the light guide plate 135 and is emitted while being guided by the light guide plate. Based on this principle, light is emitted toward the light wavelength conversion sheet 131.

The area of the light wavelength selection filter 132 is preferably smaller than the area of the light wavelength conversion sheet 131. If the area of the light wavelength selection filter 132 is made smaller than the area of the light wavelength conversion sheet 131 and is partially disposed in the illumination device, it is preferable because the color of the emitted light from the illumination device can be partially adjusted efficiently.

Other aspects in the fourth embodiment are the same as those in the third embodiment.

(Fifth embodiment)
A fifth embodiment, which is an example of the illumination device of the present invention, will be described with reference to FIGS.

FIG. 14 is a schematic diagram in the fifth embodiment of the illumination device of the present invention. A first light wavelength conversion sheet 146 and a second light wavelength conversion sheet 141 are provided, and a blue LED 143 is provided on the substrate 144 as a light emitting element. In addition, a reflection plate 147 and a diffusion plate 148 are provided to reflect and diffuse light from the light emitting element.

The first light wavelength conversion sheet 146, the blue LED 143, and the second light wavelength conversion sheet 141 are provided in this order.

The blue LED 143 is provided apart from the second light wavelength conversion sheet 141 and emits light toward the second light wavelength conversion sheet 141.

The area of the first light wavelength conversion sheet 146 is preferably smaller than the area of the second light wavelength conversion sheet 141. If the area of the first light wavelength conversion sheet 146 is made smaller than the area of the second light wavelength conversion sheet 141 and is partially disposed in the lighting device, the color of the emitted light of the lighting device is partially adjusted efficiently. This is preferable because it is possible.

FIGS. 15 and 16 are diagrams showing optical paths when there is no first optical wavelength selection filter 146 and when there is no first optical wavelength selection filter 146, respectively.

As shown in FIGS. 15 and 16, a part of the blue light emitted from the blue LED toward the second light wavelength conversion sheet 141 is reflected by the surface of the diffusion plate 148 and emitted to the side opposite to the emission surface side. The Moreover, a part is reflected also on the surface of another optical sheet and the surface of the 2nd light wavelength conversion sheet, and it radiate | emits on the opposite side to the output surface side. The light emitted to the opposite side to the emission surface side is reflected by the reflecting plate and directed to the emission surface side, and a part of the light is reflected again by the surface of the diffusion plate 148 and the like and emitted to the opposite side to the emission surface side. Repeat that.

As shown in FIG. 16, when there is the first light wavelength conversion sheet 146, the blue light emitted to the side opposite to the emission surface side peaks at a wavelength different from the peak wavelength of the blue wavelength, such as green light and red light. Then, the light is output to the output surface side by the reflector. On the other hand, as shown in FIG. 15, when there is no first light wavelength conversion sheet 146, the blue light emitted to the side opposite to the emission surface side is emitted to the emission surface side by the reflector without being wavelength-converted. Therefore, when there is the first light wavelength conversion sheet 146, the bluishness of the light emitted toward the emission surface in the vicinity of the first light wavelength conversion sheet 146 is the case of FIG. 15, that is, the first light wavelength conversion sheet 146 is When there is no light, it is reduced compared to the light emitted to the emission surface side.

Based on this principle, the light wavelength conversion sheet 146 is partially disposed in a portion with strong bluishness (a portion where the influence of the light emission color of the light emitting element is strong) such as near the end of the lighting device, so that the color unevenness of the lighting device can be obtained. Can be improved.

When the first light wavelength conversion sheet 146 is used, color adjustment can be performed with less light loss compared to other color adjustment methods that reduce blueness by the principle of absorbing blue light.

The first light wavelength conversion sheet 146 may be laminated on a reflector as shown in FIG.

The first light wavelength conversion sheet 146 may contain a quantum dot or a phosphor in a reflection plate. A sheet containing quantum dots or phosphors in a reflector plate has a wavelength conversion function and a reflection function.

The shape of the first light wavelength conversion sheet may be a planar shape, a shape having a large number of holes in the surface, a mesh shape, a circle, an ellipse, a shape surrounded by other curves, a triangle, a quadrangle, Various shapes such as other polygons may be used.

The first light wavelength conversion sheet is a sheet that converts light of a specific wavelength into light of another wavelength as described above, and contains, for example, quantum dots and phosphors having a function of converting light wavelength. It is a sheet. A resin sheet containing quantum dots or phosphors may be used, or a film containing quantum dots or phosphors may be laminated on a sheet serving as a substrate. Moreover, you may use a reflecting plate as a base material. The shape of the film containing quantum dots and phosphors to be laminated on the base sheet may be a shape with a large number of holes on the surface, a mesh shape, or a layered state such as a dot shape. Various shapes such as a circle, an ellipse, a shape surrounded by other curves, a triangle, a quadrangle, and other polygons may be used.

As the light wavelength conversion sheet, when using a film that includes a quantum dot or phosphor on a sheet serving as a substrate, the area of the film containing the quantum dot or phosphor of the first light wavelength conversion sheet is: It is preferable to make it smaller than the area of the film | membrane containing the quantum dot and fluorescent substance of a 2nd light wavelength conversion sheet. The area of the film containing the quantum dots and the phosphor of the first light wavelength conversion sheet is made smaller than the area of the film containing the quantum dots and the phosphor of the second light wavelength conversion sheet and partially arranged in the lighting device. This is preferable because the color of the light emitted from the illumination device can be partially adjusted efficiently.

Other aspects in the fifth embodiment are the same as those in the first embodiment.

(Sixth embodiment)
FIG. 18 is a schematic diagram of the sixth embodiment of the illumination device of the present invention. A first light wavelength conversion sheet 186 and a second light wavelength conversion sheet 181 are provided, and a blue LED 183 is provided as a light emitting element at an end of the light guide plate 185.

The first light wavelength conversion sheet 186, the blue LED 183, and the second light wavelength conversion sheet 181 are provided in this order.

The blue LED 183 is provided apart from the second light wavelength conversion sheet 181. The light of the blue LED 183 enters from the end of the light guide plate 185 and is emitted while being guided by the light guide plate. Based on this principle, light is emitted toward the second light wavelength conversion sheet 181.

The area of the first light wavelength conversion sheet 186 is preferably smaller than the area of the second light wavelength conversion sheet 181. If the area of the first light wavelength conversion sheet 186 is made smaller than the area of the second light wavelength conversion sheet 181 and is partially disposed in the lighting device, the color of the emitted light of the lighting device is partially adjusted efficiently. This is preferable because it is possible.

Other aspects of the sixth embodiment are the same as those of the fifth embodiment.

Hereinafter, the present invention will be described in detail with reference to examples, but the present invention is not limited to these examples. In addition, the measuring method and evaluation method in a present Example are shown below.

[Measurement method and evaluation method]
(1) Spectral spectrum of illuminating device The spectral spectrum of the central part of illuminating device A was measured in the dark room under the following conditions using the following spectral radiance meter. In determining the central portion, the central portion of the prism film (155 mm × 98 mm) installed on the uppermost surface of the lighting device A was used as the central portion of the lighting device A. The distance between the spectral radiance meter used in the illumination device and the display was 500 mm.
・ Spectral radiance meter CS-1000A (Konica Minolta Sensing Co., Ltd.)
Objective lens: Macro objective lens Measurement mode: AUTO

(2) Spectral reflectance of optical wavelength selection filter A sample was cut out at 50 mm × 50 mm. Next, the relative reflectance at an incident angle Φ = 10 degrees was measured using a spectrophotometer (U-4100 Spectrophotometer, manufactured by Hitachi, Ltd.). The inner wall of the attached integrating sphere is barium sulfate, and the standard plate is aluminum oxide. The measurement wavelength was 250 nm to 1,200 nm, the slit was 2 nm (visible) / automatic control (infrared), the gain was set to 2, and the measurement was performed at a scanning speed of 600 nm / min. The back of the sample was painted black with oil-based ink.

(3) Optical wavelength selection filter, spectral transmittance of optical sheet A sample was cut out at 50 mm × 50 mm. The transmittance was measured with a basic configuration using an integrating sphere attached to a spectrophotometer (U-4100 Spectrophotometer) manufactured by Hitachi, Ltd. (incident angle 0 °). The measurement is based on the sub-white plate of aluminum oxide attached to the apparatus, the measurement conditions are slit 2 nm (visible) / automatic control (infrared), gain 2 and scanning speed 600 nm / min. Measured with In addition, when measuring the transmittance including the polarization component, the attached Grandeira polarizer is installed, the sample is fixed in a certain direction, and the transmittance is measured by rotating the polarizer by 5 °. The angle at which was the maximum was measured.

(4) Spectral spectrum of light wavelength conversion sheet A sample was cut into 50 mm x 50 mm, the back surface of the sample was blacked with oil-based ink, and measured using the following spectrocolorimeter.
・ Spectrophotometer CM-2600d (Konica Minolta Sensing Co., Ltd.)
・ White calibration plate CM-A145 (manufactured by Konica Minolta Sensing Co., Ltd.)
・ Target mask CM-146 (for φ8mm).

(5) Color coordinates / luminance of illumination device The illumination device A is configured as described in Examples 1 to 10, and the color coordinates (x value, y value) at the center thereof are set as follows using the following spectral radiance meter. The measurement was performed in a dark room under the conditions. In determining the central portion, the central portion of the prism film (155 mm × 98 mm) installed on the uppermost surface of the lighting device A was defined as the central portion. The distance between the spectral radiance meter used in the illumination device and the display was 500 mm.
・ Spectral radiance meter CS-1000A (Konica Minolta Sensing Co., Ltd.)
・ Objective lens: Macro objective lens ・ Measurement mode: AUTO
(6) Glossiness According to the method defined in JIS-Z8741 (1997), the 60 ° specular glossiness was measured using a digital variable angle glossiness meter UGV-5D manufactured by Suga Test Instruments. Measurement was performed at n = 5, and an average value excluding the maximum value and the minimum value was defined as the glossiness.

[Lighting device used for evaluation (lighting device A)]
A Kindle Fire HDX 7 backlight was used as the illumination device A in which the light source is a blue LED and the light wavelength conversion sheet is mounted. The size of the light wavelength conversion sheet was 158 mm × 98 mm. In Example 9, the light wavelength conversion sheet mounted on the lighting device A was used as the second light wavelength conversion sheet.

FIG. 19 is a simplified diagram of the lighting device A. The configuration was a blue LED 193, a light guide plate 195, a reflective film 197 having a gloss level of 930 (excluding Example 6), a light wavelength conversion sheet 191, and a prism sheet 199 (two sheets).

As a result of measuring the spectral spectrum of the illumination device A, the blue wavelength of the blue light emitted from the blue LED has a peak at 450 nm, the green wavelength of the green light converted by the light wavelength conversion sheet, and the red wavelength of the red light are There were peaks at 550 nm and 610 nm, respectively.

[Example 1]
The optical wavelength selection filter A was obtained by the method shown below.

As polyester A, polyethylene terephthalate having an intrinsic viscosity of 0.8 was used. As the polyester B, a blend chip in which 62% by mass of a copolymerized polyester obtained by copolymerizing 30 mol% of cyclohexanedimethanol and 38% by mass of polyethylene terephthalate was used. These polyester A and polyester B were each dried and then fed to an extruder.

While each of polyester A and polyester B is melted at 280 ° C. with an extruder and measured with a gear pump so that the discharge ratio is polyester A composition / polyester B composition = 1.66 / 1, filter After passing through, it was made to merge in a feed block. The combined polyester A and polyester B are supplied to a static mixer, combined in a 501 layer feed block, and alternately laminated in the thickness direction with A / B / A... B / A and 501 layers laminated. did.

The laminate composed of the total of 501 layers thus obtained was supplied to a T die and formed into a sheet shape, and then rapidly cooled and solidified on a casting drum maintained at a surface temperature of 25 ° C. while applying electrostatic force.

The obtained cast film was heated by a roll group set at 85 ° C. to 100 ° C., stretched 3.3 times in the longitudinal direction, and then the uniaxially stretched film was led to a tenter, preheated with hot air at 100 ° C., and then heated at 110 ° C. The film was stretched 3.8 times in the width direction at temperature. The stretched film was heat-treated with hot air at a relaxation rate of 3% and 150 ° C. in a tenter, gradually cooled to room temperature, and wound up. An optical wavelength selective filter A having a thickness of 40 μm and a thickness of each layer gradually changing from 43 to 83 nm was obtained.

As a result of measuring the spectral reflectance and spectral transmittance of the optical wavelength selection filter A, the reflectance at 450 nm was 69%, the transmittance at 550 nm was 88%, and the transmittance at 610 nm was 90%.

The light wavelength selection filter A was cut out to 60 mm × 98 mm and placed between the light wavelength conversion sheet and the prism sheet of the illumination device A. When arranging, the 60 mm side was arranged in parallel with the long side of the illuminating device, and the central portion of the light wavelength selection filter A was arranged so as to be the central portion of the illuminating device A. In determining the central portion of the illumination device A, the central portion of the prism film (155 mm × 98 mm) installed in the illumination device A was defined as the central portion.

The color coordinates (x value, y value) and luminance when the optical wavelength selection filter A was arranged, and the color coordinates (x value, y value) and luminance when the optical wavelength selection filter A was not arranged were measured. The evaluation results are shown in Table 1.

[Example 2]
Except that the arrangement location of the optical wavelength selection filter A is between the two prism sheets of the illumination device A, the color coordinates (x value, (y value), luminance, and color coordinates (x value, y value) and luminance when not arranged were measured. The evaluation results are shown in Table 1.

[Example 3]
A polarizing reflection film having a degree of polarization of 90% is provided on the prism sheet of Example 1, and the direction in which the transmittance of the light selective wavelength filter A is maximized and the direction in which the transmittance of the polarization reflecting film is maximized are 90 °. The color coordinates (x value, y value) when the optical wavelength selection filter A is arranged, the luminance, and the color coordinates when the optical wavelength selection filter A is not arranged (except for the arrangement so as to be orthogonal to each other) x value, y value) and luminance were measured. The evaluation results are shown in Table 1.

[Example 4]
The optical wavelength selection filter B was implemented except that polyester B was a copolyester obtained by copolymerizing 25 mol% of spiroglycol and 30 mol% of cyclohexanedicarboxylic acid, the thickness was changed to 70 μm, and the thickness of each layer was changed stepwise from 76 to 145 nm. In the same manner as in Example 1, an optical wavelength selection filter B was obtained.

As a result of measuring the spectral reflectance and the spectral transmittance of the optical wavelength selection filter B, the transmittance at 450 nm was 90%, the reflectance at 550 nm was 34%, and the reflectance at 610 nm was 90%.

The light wavelength selection filter B is used as the light wavelength selection filter, and the light wavelength selection filter B is disposed between the light guide plate and the light wavelength conversion sheet of the illuminating device A in the same manner as in Example 1 except that the light wavelength selection filter B is disposed. The color coordinates (x value, y value) and luminance when the selection filter B was arranged, and the color coordinates (x value, y value) and luminance when the selection filter B was not arranged were measured. The evaluation results are shown in Table 1.

[Example 5]
A polarizing reflection film having a polarization degree of 90% is provided on the prism sheet of Example 4, and the direction in which the transmittance of the light selective wavelength filter B is maximized and the direction in which the transmittance of the polarization reflecting film is maximized are parallel. The color coordinates (x value, y value) and luminance when the optical wavelength selection filter B is arranged, the luminance, and the color coordinates (x value when not arranged) are the same as in Example 4 except that the arrangement is made as follows. , Y value) and luminance. The evaluation results are shown in Table 1.

[Example 6]
Except that the reflective film of Example 4 is a white film having a glossiness of 32, the color coordinates (x value, y value), luminance, and arrangement when the optical wavelength selection filter B is arranged are the same as in Example 4. The color coordinates (x value, y value) and luminance when not performed were measured. The evaluation results are shown in Table 1.

[Example 7]
Surface irregularities were provided on the optical wavelength selection filter B by the following method.

First, the light wavelength selection filter B was coated with the coating agent 1 to form a coating film having a thickness of 5 μm.

(Coating 1)
Adeka optomer KRM-2199 (Asahi Denka Kogyo Co., Ltd.) 10 parts by mass Aron Oxetane OXT-221 (Toagosei Co., Ltd.) 1 part by mass Adeka optomer SP170 (Asahi Denka Kogyo Co., Ltd.) 0.25 Part by mass Pressing a mold in which a plurality of concave grooves whose cross-sectional shape is perpendicular to the longitudinal direction is pressed against the surface coated with the coating agent 1, ultraviolet rays are emitted from the back surface of the coated surface by an ultrahigh pressure mercury lamp at 300 mJ / cm ^The coating was cured by ^two irradiations, and the mold was released to obtain a lens shape. The lens shape obtained here had a prism shape with a pitch of 2 μm and a height of 1 μm.

Subsequently, the other configuration provided in the lower part of the light wavelength conversion sheet so that the formed lens shape becomes the upper surface is the same as in Example 4, and the color coordinates (x value) when the light wavelength selection filter B is arranged. , Y value), luminance, and color coordinates (x value, y value) and luminance when not arranged. The evaluation results are shown in Table 1.

[Example 8]
Color coordinates when the optical wavelength selection filter B is arranged in the same manner as in Example 4 except that 0.1% by mass of “OB-1” manufactured by Eastman, which is a fluorescent whitening agent, is added to the polyester B. (X value, y value), luminance, and color coordinates (x value, y value) and luminance when not arranged were measured. The evaluation results are shown in Table 1.

[Example 9]
The 1st light wavelength conversion sheet A was obtained by the method shown below.

In a composite film forming apparatus having an extruder B, 100 parts by mass of polyethylene terephthalate pellets are vacuum dried and then supplied to an extruder A heated to 250 ° C. to 300 ° C. to form a polyester layer (first layer). In order to form a polyester layer (second layer), 77.5 parts by mass of a dried polyethylene terephthalate raw material and 20 parts by mass of a dried polymethylpentene resin (hereinafter sometimes abbreviated as PMP) manufactured by Mitsui Chemicals, Inc. A polyethylene terephthalate raw material is mixed with 2.5 parts by mass of a master pellet obtained by adding a phosphor to polyethylene terephthalate (“Lumogen” F Yellow 083: 400 μg / g manufactured by BASF as a phosphor with respect to the total amount of the master pellet). PMP content in the total amount of 100% by mass of 20% by mass, phosphor Was adjusted to 0 Pg / g, the polyethylene terephthalate raw material was vacuum dried and fed to an extruder B heated to 250 ~ 300 ° C., and introduced into a T-die three-layer composite in the die to melt.

Three layers of these polymers were laminated through a three-layer laminating apparatus so as to be A layer (first layer) / B layer (second layer) / A layer (first layer), and formed into a sheet form from a T-die. Further, the unstretched film obtained by cooling and solidifying this sheet-like film with a cooling drum having a surface temperature of 10 ° C. to 40 ° C. is led to a group of rolls heated to 70 to 98 ° C. Then, the film was stretched 3.6 times in the direction perpendicular to the longitudinal direction in an atmosphere heated to 120 ° C. while being guided to a tenter while holding both ends of the longitudinally stretched film with clips. Thereafter, the film was heat-fixed at 180 to 240 ° C. in a tenter to obtain a film having a thickness of 150 μm.

The color coordinates (x value) when the first light wavelength conversion sheet A is disposed in the same manner as in Example 1 except that the first light wavelength conversion sheet A is used and disposed between the reflection plate and the light guide plate of the illumination device A. , Y value), luminance, and color coordinates (x value, y value) and luminance when not arranged. The evaluation results are shown in Table 1.

[Example 10]
Master pellets obtained by adding phosphor to polyethylene terephthalate to 79.75 parts by weight of dried polyethylene terephthalate raw material and 20 parts by weight of dried polymethylpentene resin manufactured by Mitsui Chemicals to form a polyester layer (second layer) (Plum content of 100% by mass of polyethylene terephthalate raw material by mixing 0.25 parts by mass of “Lumogen” F Yellow 083: 400 μg / g made by BASF as phosphor with respect to the total amount of master pellets) A film was prepared in the same manner as in Example 4 except that the amount was adjusted to 20 mass% and the phosphor was 1 μg / g, and the first light wavelength conversion sheet B was obtained.

The color coordinates (x value) when the first light wavelength conversion sheet B is disposed in the same manner as in Example 1 except that the first light wavelength conversion sheet B is used and disposed between the reflection plate and the light guide plate of the illumination device A. , Y value), luminance, and color coordinates (x value, y value) and luminance when not arranged. The evaluation results are shown in Table 1.

[Evaluation]
The lighting device was measured and evaluated according to the above-described example. The results are shown in Table 1. FIG. 20 shows an xy chromaticity diagram.

As described in Table 1, when the light wavelength selection filters A and B and the first light wavelength conversion sheets A and B are arranged, either the x value or the y value is compared with the case where they are not arranged. Either is larger at the same value, or both are larger. The largest change in the x and y values was in Example 2, followed by Example 1.

Here, as shown in the xy chromaticity diagram of FIG. 20, the coordinate position of the strong blue color is the direction in which the x value and the y value become smaller, and on the contrary, the blue color is reduced. , X value and y value become larger.

When the light wavelength selection filters A and B and the first light wavelength conversion sheets A and B are disposed, either the x value or the y value is the same value and either is greater than when the light wavelength selection filters A and B are not disposed. Or both are large, that is, the bluish color is reduced, and the light wavelength selection filters A and B and the first light wavelength conversion sheets A and B are partially arranged in the vicinity of the strong bluish color in the lighting device. If it arrange | positions to, the color nonuniformity of an illuminating device can be adjusted.

11, 21, 31, 81, 91, 131, 191 ... light

wavelength conversion sheets

141, 181 ... second light

wavelength conversion sheets

32, 82, 92, 132 ... light wavelength selection filters 13, 23, 33, 83, 93, 133, 143, 183, 193 ... Blue LED
14, 24, 34, 94, 144 ...

substrates

85, 135, 185, 195 ...

light guide plates

146, 186 ... first light

wavelength conversion sheets

17, 37, 97, 147, 187, 197 ...

Reflector

18, 28, 38, 98, 148 ...

diffuser

19, 29 ... optical sheet 199 ... prism sheet 20 ... liquid crystal panel (display panel)
30 ... Lighting device

Claims

A light wavelength conversion sheet;
An optical wavelength selection filter;
A light emitting element;
A lighting device comprising:
A light emitting element, a light wavelength conversion sheet, and a light wavelength selection filter are provided in this order,
The area of the light wavelength selection filter is smaller than the area of the light wavelength conversion sheet,
The illuminating device, wherein the light emitting element is separated from the light wavelength conversion sheet.
A light wavelength conversion sheet;
An optical wavelength selection filter;
A light emitting element;
A lighting device comprising:
A light emitting element, an optical wavelength selection filter, and an optical wavelength conversion sheet are provided in this order.
The area of the light wavelength selection filter is smaller than the area of the light wavelength conversion sheet,
The illuminating device, wherein the light emitting element is separated from the light wavelength conversion sheet.
A first light wavelength conversion sheet;
A second light wavelength conversion sheet;
A light emitting element;
A lighting device comprising:
The first light wavelength conversion sheet, the light emitting element, and the second light wavelength conversion sheet are provided in this order,
The area of the first light wavelength conversion sheet is smaller than the area of the second light wavelength conversion sheet,
The illuminating device, wherein the light emitting element is provided apart from the second light wavelength conversion sheet.
The lighting device according to claim 1, wherein the optical wavelength selection filter satisfies the following expression (1).
| λ2-λ3 | ≦ 50 (where λ1 <λ2, λ1 <λ3) (1)
λ1: Light emission wavelength of light emitting element (nm)
λ2: wavelength at which the transmittance of the optical wavelength selection filter becomes 70% (nm)
λ3: wavelength at which the transmittance of the optical wavelength selection filter is 30% (nm)
The illumination device according to any one of claims 1 to 3, wherein a surface of the light wavelength selection filter and / or the light wavelength conversion sheet has an uneven shape.
The lighting device according to claim 1, wherein a plurality of the light emitting elements are provided corresponding to the entire surface of the light wavelength conversion sheet.
The lighting device according to claim 3, wherein a plurality of the light emitting elements are provided corresponding to the entire surface of the second light wavelength conversion sheet.
The illuminating device according to claim 1, further comprising a light guide plate disposed in an optical path from the light emitting element to the light wavelength conversion sheet for light emitted from the light emitting element.
The lighting device according to claim 3, further comprising a light guide plate disposed in an optical path from the light emitting element to the second light wavelength conversion sheet for light emitted from the light emitting element.
The lighting device according to claim 8, wherein a plurality of the light emitting elements are provided along an end portion of the light guide plate.
4. The method according to claim 1, further comprising a brightness enhancement film, wherein the brightness enhancement film is provided on an emission side of any member of the light emitting element, the light wavelength sheet, and the light wavelength selection filter. A lighting device according to claim 1.
The angle between the direction in which the transmittance at the wavelength λ3 of the optical wavelength selection filter is maximized and the direction in which the transmittance at the wavelength λ3 of the brightness enhancement film is maximized is 10 ° or less. 11. The illumination device according to 11.
The angle between the direction in which the transmittance at the wavelength λ3 of the optical wavelength selection filter is maximized and the direction in which the transmittance at the wavelength λ3 of the brightness enhancement film is maximized is 80 ° or more. 11. The illumination device according to 11.
Further, it comprises a regular reflective film, and is provided with the regular reflective film opposite to the exit side from any member of the light emitting element, the light wavelength sheet, and the light wavelength selection filter. The lighting device according to any one of claims 1 to 3.
A display device comprising a display panel and a lighting device provided adjacent to the display panel,
The lighting device is
A display device comprising the illumination device according to any one of claims 1 to 14.