TWI669463B - Optical film and illuminating device - Google Patents

Abstract

An optical film and a light-emitting device, the optical film comprising a body and a side barrier layer. The body includes a first substrate and a second substrate spaced apart, and an active layer between the two substrates. The first substrate and the second substrate respectively have a light incident surface and a light exit surface. The active layer includes a plurality of quantum dots that are excited by a first color light to emit a second color light having a wavelength greater than a wavelength of the first color light. The side barrier layer is coupled to one side of the body, and is configured to block the first color light from entering the body through the side from the outside of the body, thereby avoiding unnecessary light entering, and not being expected to be excited by light. Mixed light is produced. The invention has good optical effect and light-emitting quality, and makes the mixed color and brightness uniform.

Description

Optical film and illuminating device

The present invention relates to an optical film and a light-emitting device, and more particularly to an optical film that can be excited by light to emit light, and a light-emitting device having the same.

One of the known ways to produce white light by a light emitting diode (LED) light-emitting device is to use a film containing quantum dots as a light-emitting layer of a light-emitting diode, by different materials or particle diameters. The quantum dots are irradiated by the excitation light source, and a secondary light having a wavelength different from that of the excitation light source is emitted and mixed. For example, a blue LED can be used as an excitation light source, and quantum dot materials of different particle sizes can be excited to generate red light and green light, and red light, green light, and blue light can be mixed to form white light.

The above-mentioned light-emitting device including the quantum dot optical film can be applied to the backlight module of the display, and the backlight module containing the quantum dot optical film can provide more rich color tone and chroma of the display than the conventional backlight module. The color gamut is wide, the color is rich and more realistic, and the display is saturated with color and bright.

The quantum dot optical film includes a light incident surface facing the blue LED light source, a light emitting surface opposite to the light incident surface and facing the panel module of the display, and a side connected to the light incident surface and the peripheral edge of the light emitting surface . In practice, it is found that the blue light emitted by the blue LED light source does not necessarily enter the film from the light incident surface of the quantum dot optical film. Some of the blue light may not be affected by reflection, refraction, or internal structure of the display. In the quantum dot optical film, but from the outer lateral direction of the quantum dot optical film, the film enters the film through the periphery of the side surface. Therefore, when the quantum dot optical film is observed, it is found that the surrounding side edge is annular. The blue light region, and the blue light entering the quantum dot optical film from the side, because it is not originally designed and desired, the light path of the blue light is difficult to grasp, and the quantum dots are unexpectedly excited and mixed. The light causes the illuminating effect of the original setting to be destroyed. Therefore, the color at the four peripheral sides of the quantum dot optical film may be deviated, and the illuminating color is not uniform. If applied to the display, the blue light around the display is more obvious, and the color and the view are different. Feeling bad.

Accordingly, it is an object of the present invention to provide an optical film and a light-emitting device which can provide a uniform light mixing effect by preventing light from entering from the side.

Thus, the optical film of the present invention comprises a body and a side barrier. The body includes a first substrate, a second substrate, an active layer, and a side surface. The first substrate includes an opposite first side and a light incident surface. The second substrate is spaced apart from the first substrate and includes a second surface facing the first surface and a light emitting surface opposite to the second surface. The active layer is located between the first surface of the first substrate and the second surface of the second substrate, the active layer includes a plurality of quantum dots, and the quantum dots can be excited by a first color light A second color light having a wavelength greater than a wavelength of the first color light is emitted. The side surface extends from the peripheral edge of the light incident surface toward the periphery of the light exit surface. The side barrier layer is disposed on the side of the body, and the side barrier layer is configured to block the first color light from entering the body through the side from the outside of the body.

The light-emitting device of the present invention comprises an optical film as described above, and a light-emitting unit located on one side of the light-incident surface of the optical film. The light emitting unit can emit the first color light, the first color light enters the inside of the body from the light incident surface, and excites the quantum dots to emit the second color light, and the first color light and the second color light After the light is mixed, the light exiting surface is emitted.

The effect of the invention is that: by the side barrier layer being disposed on the side surface, the first color light can be blocked from entering the body of the optical film from the side surface, thereby avoiding unnecessary light entering, thereby avoiding being unintended The light excitation and the mixed light generation can improve the problem that a clear blue light ring is observed around the optical film. Therefore, the invention has good optical effect and light-emitting quality, so that the mixed color and brightness are uniform.

Before the present invention is described in detail, it should be noted that in the following description, similar elements are denoted by the same reference numerals.

Referring to Figures 1 and 2, a first embodiment of a light-emitting device of the present invention comprises an optical film 1, and a light-emitting unit 2.

The optical film 1 comprises a body 3 and a side barrier layer 4. The body 3 includes a first substrate 31 and a second substrate 32 spaced apart from each other, an active layer 33 between the first substrate 31 and the second substrate 32, and a side surface 34.

The first substrate 31 includes a first surface 311 and a light incident surface 312 opposite to the first surface 311 and facing the light emitting unit 2 . The second substrate 32 is away from the light emitting unit 2 with respect to the first substrate 31 and includes a second surface 321 facing the first surface 311 and a light emitting surface 322 opposite to the second surface 321 . The material of the first substrate 31 and the second substrate 32 may be polyethylene terephthalate (PET), cycloolefin (co)-polymers (COC), Polyimide (PI), polyether sulfonate (PES), polyethylene naphthalate (PEN), polycarbonate (PC), or any of the foregoing materials combination.

The active layer 33 is located between the first surface 311 and the second surface 321 . The active layer 33 includes a plurality of quantum dots 331 , and the quantum dots 331 can be excited by a first color light to emit a second color light. a third color light having a wavelength greater than a wavelength of the first color light, the third color light having a wavelength greater than a wavelength of the second color light. In this embodiment, the first color light is blue light, the second color light is green light, and the third color light is red light.

Specifically, the active layer 33 may be prepared by dispersing the quantum dots 331 in a colloidal system. The material of the colloidal system is a light transmissive resin and has a light uniform effect, followed by coating. The first surface 311 of the first substrate 31 or the second surface 321 of the second substrate 32 is formed to form a film, and then the material of the quantum dots 331 can be selected to be annealed. This active layer 33 is obtained. The quantum dots 331 are nanocrystalline semiconductor materials, mainly semiconductor quantum dots 331 synthesized by II-VI or III-V compounds, which can emit a second difference from the excitation light after being irradiated by the excitation light. The light rays, and the quantum dots 331 can change the wavelength of the light emitted by the excitation light by the selection of the material or the adjustment of the particle size, thereby emitting a color light of a different color from the excitation light.

The side surface 34 of the optical film 1 is defined by the first substrate 31 and the second substrate 32 together with the active layer 33. The side surface 34 extends from the periphery of the light incident surface 312 toward the periphery of the light exit surface 322 and has a shape surrounded by four sides.

The side barrier layer 4 is bonded to the side surface 34 of the body 3 at a position that covers the first substrate 31, the second substrate 32, and the active layer 33. The side barrier layer 4 is configured to block the first color light from entering the body 3 via the side surface 34 from outside the body 3 . Specifically, the side barrier layer 4 of the embodiment can block the blue light from entering the body 3 through the side surface 34 by the function of absorbing blue light from the material. Preferably, the side barrier layer 4 is a UV-curable adhesive that can be cured by ultraviolet light, so that the material of the side barrier layer 4 is applied to the side surface 34, and can be quickly cured after being irradiated with ultraviolet light, so that the present invention It is faster and easier to manufacture. The color of the side barrier layer 4 is substantially yellow. Preferably, the thickness d of the side barrier layer 4 in the horizontal direction is about 100 μm to 200 μm. Within this thickness range, the side barrier layer 4 has a good blue light blocking effect, and does not protrude too much because it is too thick. This side 34. In addition, the side barrier layer 4 also has a function of blocking moisture, which can prevent moisture from entering the interior of the body 3, thereby avoiding the problem that the body 3 is affected by moisture and the optical performance is deteriorated or the life of the diaphragm is shortened. In practice, the side barrier layer 4 can also use a material that reflects blue light, such as a heat-curable material having a blue-reflecting function, so that blue light can also be blocked from entering the body 3 through the side surface 34.

The light emitting unit 2 is located on the light incident surface 312 side of the optical film 1, and includes a circuit substrate 21, and a plurality of light emitting diodes 22 on the circuit substrate 21 for emitting the first color light.

When the present invention is used, the first color light (blue light) emitted by the light-emitting diodes 22 enters the inside of the body 3 from the light-incident surface 312 of the optical film 1 and excites the quantum dots 331 to emit the second color. The color light (green light) and the third color light (red light), the first color light, the second color light and the third color light are mixed to generate white light, and are emitted through the light exit surface 322 of the optical film 1. The light-emitting device of the present invention can be applied to a display as a backlight module, and is disposed on a side of a panel module (not shown) of the display, and the light-emitting surface 322 faces the panel module, so that the mixed light can pass through the light-emitting device. Face 322 is directed toward the panel module.

In the first color light emitted by the light-emitting unit 2, part of the first color light may not enter the optical film 1 directly through the light-incident surface 312 due to the initial light-emitting direction, or being reflected, refracted, or the like. And the lateral direction is directed to the side surface 34 of the optical film 1 (as shown by the light path A in FIG. 2), but the first color light can be blocked by the side barrier layer 4 disposed on the side surface 34. The side surface 34 enters the body 3, thereby avoiding unnecessary light entering, thereby avoiding unintended light excitation and light mixing, and improving the problem that a clear blue light ring is observed around the optical film. Therefore, the invention has good optical effect and light-emitting quality, makes the mixed color and brightness uniform, and is applied to the display, so that the display color is saturated and rich, and a higher quality color effect can be realized. Moreover, the water vapor barrier function of the side barrier layer 4 maintains the diaphragm quality and optical function of the optical film 1 and prolongs the service life of the diaphragm.

Referring to FIG. 3, a second embodiment of the illuminating device of the present invention is substantially the same as the structure of the first embodiment. The difference is that the first substrate 31 of the embodiment further includes a plurality of the illuminating surfaces 312. The first microstructure 313. The second substrate 32 further includes a plurality of second microstructures 323 located on the light exit surface 322. The first microstructures 313 and the second microstructures 323 have light diffusion and homogenization effects, and the materials may be polymethyl methacrylate (acrylic), polyurethane (PU), and epoxy resin (silicone). ), or any combination of the above materials. The shapes of the first microstructures 313 may be the same or different, and the shapes of the second microstructures 323 may also be the same or different, and the shapes may be tapered, semi-circular, regular hexagonal, irregular concave-convex structures, and the like. The first color structure 313 can refract the first color light emitted by the light emitting unit 2 to increase the light path of the first color light in the active layer 33, and can excite more of the quantum Point 331 effectively improves the conversion efficiency of green and red light, and produces more green and red light, which can be applied to the display to achieve wide color gamut, color saturation, and vivid effects. In addition, the second microstructures 323 are disposed on the second substrate 32, which can effectively reduce the total reflection phenomenon caused by the light emitted from the surface of the light-emitting surface 322, thereby improving the overall light extraction rate.

Referring to FIG. 4, a third embodiment of the illuminating device of the present invention is substantially the same as the structure of the second embodiment, except that the active layer 33 of the embodiment further includes a plurality of layers dispersed in the active layer 33. Medium and can be used for scattering particles 332 that scatter light. The first color light entering the active layer 33 can cause multiple reflections and scattering when contacting the scattering particles 332 by the scattering particles 332 to increase the first color light in the active layer 33. The light path enhances the probability of photons colliding with the quantum dots 331 and increases the intensity of the secondary rays emitted by the quantum dots 311 after excitation, thereby improving the luminance of the present invention.

However, the above is only the embodiment of the present invention, and the scope of the invention is not limited thereto, and all the equivalent equivalent changes and modifications according to the scope of the patent application and the patent specification of the present invention are still The scope of the invention is covered.

1‧‧‧Optical film

2‧‧‧Lighting unit

21‧‧‧ circuit board

22‧‧‧Lighting diode

3‧‧‧ Ontology

31‧‧‧First substrate

311‧‧‧ first side

312‧‧‧Into the glossy surface

313‧‧‧First microstructure

32‧‧‧Second substrate

321‧‧‧ second side

322‧‧‧Glossy

323‧‧‧Second microstructure

33‧‧‧Working layer

331‧‧‧ Quantum dots

332‧‧‧scattering particles

34‧‧‧ side

4‧‧‧Side barrier

A·‧‧‧ray path

D‧‧‧thickness

BRIEF DESCRIPTION OF THE DRAWINGS Other features and advantages of the present invention will be apparent from the embodiments of the present invention, wherein: Figure 1 is a perspective view of an optical film of a first embodiment of the light-emitting device of the present invention; 3 is an incomplete partial cross-sectional view of a second embodiment of the illumination device of the present invention; and FIG. 4 is an incomplete view of a third embodiment of the illumination device of the present invention. Partial section view.

Claims (9)

An optical film comprising: a body comprising a first substrate comprising an opposite first surface and a light incident surface, a second substrate spaced apart from the first substrate and including a facing a second side of one side, and a light emitting surface opposite to the second side, an active layer between the first side of the first substrate and the second side of the second substrate, the effect The layer includes a plurality of quantum dots, wherein the quantum dots are excited by a first color light to emit a second color light having a wavelength greater than a wavelength of the first color light, and a side surface from the periphery of the light incident surface toward the periphery of the light exit surface And a side barrier layer disposed on the side of the body, the side barrier layer is configured to block the first color light from entering the body through the side from the outside of the body; wherein the position of the side barrier layer covers The first substrate, the second substrate, and the active layer. The optical film of claim 1, wherein the side barrier layer is a UV curable adhesive that is curable by ultraviolet light. The optical film according to claim 2, wherein the side barrier layer has a thickness in the horizontal direction of 100 μm to 200 μm. The optical film of claim 1, wherein the first substrate further comprises a plurality of first microstructures located on the light incident surface. The optical film of claim 4, wherein the second substrate further comprises a plurality of second microstructures on the light exiting surface. The optical film of claim 1, wherein the active layer further comprises a plurality of scattering particles that can be used to scatter light. The optical film of claim 1, wherein the first color light further excites the quantum dots to emit a third color light having a wavelength greater than a wavelength of the second color light, the first color light being blue light, the second color The color light is green light, and the third color light is red light. A light-emitting device comprising: the optical film according to any one of claims 1 to 6; and a light-emitting unit located on a side of the light-incident surface of the optical film and capable of emitting the first color light, The first color light enters the inside of the body from the light incident surface, and excites the quantum dots to emit the second color light, and the first color light and the second color light are mixed and emitted from the light emitting surface. The illuminating device of claim 8, wherein the first color light further excites the quantum dots to emit a third color light having a wavelength greater than a wavelength of the second color light, the first color light being blue light, the second color The color light is green light, and the third color light is red light. The first color light, the second color light and the third color light are mixed by the light emitting surface, and the light emitting unit includes at least one for emitting the first color. Light emitting diode.