TW201817590A - Optical film with excellent optical effect, light-emitting quality, and uniform light-mixing color and brightness - Google Patents

Abstract

The optical film comprises a first base material and a second base material which are spaced from each other, and a first excitation layer and a second excitation layer which are positioned between the two substrates. The first excitation layer comprises a plurality of first quantum structures made of a first material. The first quantum structure can be excited by a first color light, and emits a second color light and a third color light with wavelengths larger than the wavelength of first color light. The second excitation layer comprises a plurality of second quantum structures made of a second material, and the second quantum structure can be excited by the first color light to emit the second color light. The first excitation layer and the second excitation layer are matched in a double-layered manner with excellent optical effect, light-emitting quality, and uniform light-mixing color and brightness. The display device is applied to the display, so that the color of the display is saturated and rich, and the high-quality color effect can be achieved.

Description

Optical film

The present invention relates to an optical film, and particularly to an optical film capable of being excited by light to emit light.

One way of generating white light by known light emitting diode (LED) light emitting devices is to use a thin film containing quantum dots as a light emitting layer, and the quantum dots of different materials or particle sizes are excited by the light source. Irradiation, mixed light after emitting secondary light with a wavelength different from the excitation light source. For example, the known quantum dot optical film mainly includes an excitation layer, and the excitation layer contains quantum dot materials of different particle sizes. The quantum dot materials, such as CdSe-based materials, can use blue LEDs as the excitation light source, and Exciting the quantum dots with different particle diameters to generate red light and green light, the red light, green light, and blue light can be mixed to form white light.

The above-mentioned light-emitting device including a quantum dot optical film can be applied to a backlight module of a display. Compared with a conventional backlight module, a backlight module including a quantum dot optical film can provide a display with richer color levels and chroma. , The color gamut is wide, the color expression is rich and more real, so that the display presents high-quality picture quality with saturated colors and vivid colors.

In view of the demand for high-quality display image quality, the applicant of this case believes that the above-mentioned optical film can be further improved, and the possibility of applying other materials is sought to improve the color gamut breadth and color saturation.

It is therefore an object of the present invention to provide an optical film which overcomes at least one of the disadvantages of the prior art.

Therefore, the optical film of the present invention includes a first substrate, a second substrate, a first excitation layer, and a second excitation layer which are opposed to each other.

The first excitation layer is located between the first substrate and the second substrate, and includes a plurality of first quantum structures made of a first material. The first quantum structures are quantum dots or quantum rods. While some of the first quantum structures can be excited by a first color light to emit a second color light having a wavelength longer than that of the first color light, the other few of the first quantum structures can be excited by the first color. The light is excited to emit a third color light, the wavelength of the third color light is greater than the wavelength of the first color light, and is different from the wavelength of the second color light. The second excitation layer is located between the first excitation layer and the second substrate, and includes a plurality of second quantum structures made of a second material different from the first material. The second quantum structures are For quantum dots or quantum rods, the second quantum structures can be excited by the first color light to emit the second color light.

Another optical film provided by the present invention includes a first substrate, a second substrate, a third substrate, a second excitation layer, and a third excitation layer opposite to each other. The third substrate is located between the first substrate and the second substrate. The second excitation layer is located between the first substrate and the third substrate, and includes a plurality of second quantum structures. The second quantum structures are quantum dots or quantum rods. The first color light is excited to emit a second color light having a wavelength greater than that of the first color light. The third excitation layer is located between the third substrate and the second substrate, and includes a plurality of third quantum structures. The third quantum structures are quantum dots or quantum rods. The first color light is excited to emit a third color light having a wavelength greater than the wavelength of the first color light, and the wavelength of the third color light is different from the wavelength of the second color light. The second and third quantum structures are CsPbX ₃ or CH ₃ NH ₃ PbX ₃ , and X is chlorine, bromine, iodine, or any combination thereof.

The effect of the present invention is that by using the double layer of the first excitation layer and the second excitation layer, compared with the conventional quantum dot optical film using only a single excitation layer, it has better optical effect and light quality. , Make the mixed light color and brightness uniform, apply to the display, make the display color saturation, rich, can achieve higher quality color effects.

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

Referring to FIG. 1, a first embodiment of an optical film of the present invention can be excited by a first color light emitted from a light-emitting unit 1. The light-emitting unit 1 includes a circuit board 11 and a plurality of circuit boards 11. And a light emitting diode 12 capable of emitting the first color light. The optical film includes a first substrate 21 and a second substrate 22 which are opposed to each other, and a first excitation layer 31 and a second excitation layer located between the first substrate 21 and the second substrate 22. 32. A third excitation layer 33, a third substrate 23 and a fourth substrate 24.

The first substrate 21 includes a first surface 211 and a light incident surface 212 opposite to the first surface 211 and facing the light emitting unit 1. The second substrate 22 is far from the light emitting unit 12 relative to the first substrate 21 and includes a second surface 221 facing the first surface 211 and a light emitting surface 222 opposite to the second surface 221. The materials of the first substrate 21 and the second substrate 22 may be polyethylene terephthalate (PET), cyclo olefin (co) -polymers (COC), Polyimide (PI), Polyestersulfone (PES), Polyethylene naphthalate (PEN), Polycarbonate (PC), or any of the foregoing materials combination. More preferably, the first substrate 21 and the second substrate 22 in this embodiment are both a water blocking substrate capable of blocking the entry of water vapor, thereby preventing water vapor from affecting the excitation layers 31, 32, 33.

The first excitation layer 31 includes a plurality of first quantum structures 311 made of a first material. The first quantum structures 311 are quantum dots or quantum rods. Some of the first quantum structures 311 can be excited by a first color light to emit a second color light having a wavelength longer than the wavelength of the first color light, and the other several of the first quantum structures 311 can be The first color light is excited to emit a third color light, and the wavelength of the third color light is greater than the wavelength of the first color light and is different from the 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 first excitation layer 31 may be prepared by dispersing the first quantum structures 311 in a colloidal system. The colloidal system is made of a light-transmissive resin and has a uniform light effect. The first excitation layer 31 can be obtained by applying a coating method on the first surface 211 of the first substrate 21 to form an adhesive film. Then, depending on whether the materials of the quantum structures are annealed or not, the first excitation layer 31 can be obtained. The first quantum structures 311 are nanocrystalline semiconductor materials, mainly semiconductor quantum structures synthesized from II-VI or III-V compounds, such as CdSe quantum dots or quantum rods, which can be irradiated by excitation light. , Which emits secondary light different from the excitation light, and the first quantum structures 311 can change the emission wavelength after being irradiated by the excitation light through the selection of the material or the adjustment of the particle size, thereby emitting a different color from the excitation light Shade.

The second excitation layer 32 is located between the first excitation layer 31 and the second substrate 22 and includes a plurality of second quantum structures 321 made of a second material different from the first material. The two quantum structures 321 can be excited by the first color light to emit the second color light. The third excitation layer 33 is located between the second excitation layer 32 and the second substrate 22 and includes a plurality of third quantum structures 331 including the second material. One color light is excited to emit the third color light.

The second quantum structures 321 and the third quantum structures 331 are quantum dots or quantum rods, and the main materials are different from the first quantum structures 311. The materials of the second quantum structure 321 and the third quantum structure 331 in this embodiment are CsPbX ₃ or CH ₃ NH ₃ PbX ₃ , and X is chlorine, bromine, iodine, or any combination thereof. Wherein the quantum structure of a second embodiment 321 of the present embodiment is excited to emit green light, which material CsPbBr ₃ or CH ₃ NH ₃ PbBr ₃ mainly, a third quantum structure 331 is excited to emit red light, for example, a material which comprises CsPbBr _{(3 -y)} I _y , or containing CH ₃ NH ₃ PbBr _(3-y) I _y , where 0 <y <3. Therefore, the first material used to make the first quantum structure 311 described in this embodiment is a CdSe-based material, which is used to make the second material of the second quantum structure 321 and the third quantum structure 331. Examples are CsPbX ₃ based materials or CH ₃ NH ₃ PbX ₃ based materials. The preparation method of the second excitation layer 32 and the third excitation layer 33 is substantially the same as that of the first excitation layer 31 except that the materials and coating positions are different. The second excitation layer 32 and the third excitation layer 33 are coated separately. On the surfaces of the third substrate 23 and the fourth substrate 24.

The third substrate 23 is located between the first excitation layer 31 and the second excitation layer 32, and the fourth substrate 24 is located between the second excitation layer 32 and the third excitation layer 33. The third substrate 23 and the fourth substrate 24 are both polymer materials, and may be the same as the materials listed above for the first substrate 21 and the second substrate 22.

When the present invention is used, the first color light (blue light) emitted by the light emitting diodes 12 enters the optical film from the light incident surface 212 of the first substrate 21 and excites the first quantum structures 311 The second color light (green light) and the third color light (red light) are emitted, and then the first color light passes through the second excitation layer 32 and excites the second quantum structures 321 to emit the second color light. One color light passes through the third excitation layer 33 and excites the third quantum structures 331 to emit the third color light. The first color light and the second color light emitted from the excitation layers 31 to 33 are mixed with the third color light to generate white light, and are emitted through the light emitting surface 222 of the second substrate 22. The optical film and the light-emitting unit 1 of the present invention can be applied to a display as a backlight module, and placed on a panel module (not shown) side of the display, and the light emitting surface 222 faces the panel module, so that Light rays can be emitted to the panel module through the light emitting surface 222.

Preferably, the thicknesses of the first excitation layer 31, the second excitation layer 32, and the third excitation layer 33 may be 20 μm to 200 μm, respectively. Through the above-mentioned thickness range, the ratio of the excited second-color light and the third-color light is made appropriate to mix with the first-color light into a uniform white light. The third excitation layer 33 can also be omitted in the present invention, because the green light and the red light of the first excitation layer 31 can be matched by the cooperation of the first excitation layer 31 and the second excitation layer 32. Matching the second excitation layer 32 with additional green light with relatively pure colors can increase the color gamut and saturate colors. Furthermore, the third excitation layer 33 emits red light, in addition to improving the breadth of the color gamut, it can also increase the brightness of the mixed light.

In summary, the present invention has a better optical effect by using a double layer of the first excitation layer 31 and the second excitation layer 32 compared to the conventional quantum dot optical film using only a single excitation layer. And the light output quality, make the mixed light color and brightness uniform, applied to the display, make the display color saturation, rich, can achieve higher quality color effects. In addition, the first substrate 21 and the second substrate 22 have a function of blocking water vapor, so that the quality and optical function of the film of the optical film can be maintained, and the service life of the film can be extended.

Referring to FIG. 2, a second embodiment of the optical film of the present invention is substantially the same as the first embodiment, except that the first excitation layer 31 (FIG. 1) in the first embodiment is omitted in this embodiment. And one of the substrates, therefore, the optical film of this embodiment includes the first substrate 21 and the second substrate 22 opposite to each other, and the first substrate 21 and the second substrate 22 located between the first substrate 21 and the second substrate 22 The third substrate 23, the second excitation layer 32 and the third excitation layer 33. The second excitation layer 32 is located between the first substrate 21 and the third substrate 23. The third excitation layer 33 is located between the third substrate 23 and the second substrate 22. The materials and film characteristics of the first substrate 21, the second substrate 22, the second excitation layer 32, and the third excitation layer 33 in this embodiment are the same as those in the first embodiment, and will not be described again. The third substrate 23 of this embodiment has the same material and film characteristics as the third substrate 23 and the fourth substrate 24 of the first embodiment.

In this embodiment, the second excitation layer 32 and the third excitation layer 33 can absorb the first color light, and respectively emit the second color light and the third color light, and then each color light is mixed to form white light, so that the mixed light is mixed. Uniform color, uniform brightness, good optical effect and light quality. Moreover, in this embodiment, the first excitation layer 31 and one of the substrates in the first embodiment are omitted, which can reduce the cost of the optical film. The quantum structure of each layer in this embodiment uses a CsPbX ₃ series material or a CH ₃ NH ₃ PbX ₃ series material, and the use of Cd metal can be avoided.

Referring to FIG. 3, a third embodiment of an optical film light-emitting device according to the present invention has substantially the same structure as the first embodiment, except that the first substrate 21 of this embodiment further includes a plurality of light-emitting devices. First microstructure 213 of the surface 212. The second substrate 22 further includes a plurality of second microstructures 223 on the light emitting surface 222. The first microstructures 213 and the second microstructures 223 have a light diffusing and homogenizing effect. The materials may be polymethyl methacrylate (acrylic), polyurethane (PU), or silicone. ), Or any combination of the above. The shapes of the first microstructures 213 may be the same or different, and the shapes of the second microstructures 223 may also be the same or different. The shape may be a cone, a semicircle, a regular hexagon, an irregular concave-convex structure, and the like. The first microstructures 213 can refract the first color light emitted by the light-emitting unit 1 to increase the light path of the first color light in the optical film, and can excite more of the quantum structures. 311, 321, and 331 emit light, which effectively improves the conversion efficiency of green light and red light, and generates more green light and red light. When applied to displays, it can achieve wide color gamut, color saturation, and vivid effects. In addition, disposing the second microstructures 223 on the second substrate 22 can effectively reduce the total reflection phenomenon caused by the light emitted from the surface of the light emitting surface 222, thereby improving the overall light extraction rate.

It is added that the first substrate 21 having the first microstructures 213 and the second substrate 22 having the second microstructures 223 in this embodiment can also be applied to the aforementioned first embodiment of the present invention. In the second embodiment.

However, the above are only examples of the present invention. When the scope of implementation of the present invention cannot be limited in this way, any simple equivalent changes and modifications made in accordance with the scope of the patent application and the content of the patent specification of the present invention are still Within the scope of the invention patent.

1‧‧‧light-emitting unit

11‧‧‧circuit board

12‧‧‧light-emitting diode

21‧‧‧ the first substrate

211‧‧‧ the first side

212‧‧‧Into the light surface

213‧‧‧The first microstructure

22‧‧‧Second substrate

221‧‧‧Second Side

222‧‧‧light surface

223‧‧‧Second microstructure

23‧‧‧ third substrate

24‧‧‧ Fourth substrate

31‧‧‧first excitation layer

311‧‧‧first quantum structure

32‧‧‧second excitation layer

321‧‧‧Second quantum structure

33‧‧‧ third excitation layer

331‧‧‧ third quantum structure

Other features and effects of the present invention will be clearly presented in the embodiment with reference to the drawings, in which: FIG. 1 is an incomplete cross-sectional schematic view showing a first embodiment and a light emitting unit of the optical film of the present invention Figure 2 is an incomplete cross-sectional schematic diagram showing a second embodiment and a light emitting unit of the optical film of the present invention; and Figure 3 is an incomplete cross-sectional schematic diagram showing a third embodiment of the optical film of the present invention Example with a light-emitting unit.

Claims (11)

An optical film includes: a first substrate and a second substrate opposite to each other; a first excitation layer located between the first substrate and the second substrate, and including a plurality of first materials The first quantum structures are made. The first quantum structures are quantum dots or quantum rods. Several of the first quantum structures can be excited by a first color light and emit a light having a wavelength greater than the first color light. The second color light of the wavelength, the other several of the first quantum structure can be excited by the first color light to emit a third color light, the wavelength of the third color light is greater than the wavelength of the first color light, and is different from the The wavelength of the second color light; and a second excitation layer, located between the first excitation layer and the second substrate, and including a plurality of second quantum structures made of a second material different from the first material The second quantum structures are quantum dots or quantum rods, and the second quantum structures can be excited by the first color light to emit the second color light. The optical film according to claim 1, further comprising a third excitation layer located between the second excitation layer and the second substrate. The third excitation layer includes a plurality of third quantum particles including the second material. Structure, the third quantum structures are quantum dots or quantum rods, and the third quantum structures can be excited by the first color light to emit the third color light. The optical film according to claim 2, wherein a thickness of the first excitation layer, the second excitation layer, and the third excitation layer is 20 μm to 200 μm. The optical film according to claim 1, wherein the second quantum structures are CsPbX ₃ or CH ₃ NH ₃ PbX ₃ , and X is chlorine, bromine, iodine, or any combination thereof. The optical film according to claim 1, wherein the first substrate and the second substrate are both a water-blocking substrate capable of blocking moisture from entering. The optical film according to any one of claims 1 to 5, wherein the first color light is blue light, the second color light is green light, and the third color light is red light. The optical film according to claim 2, further comprising a third substrate between the first excitation layer and the second excitation layer, and a fourth substrate between the second excitation layer and the third excitation layer. The third substrate and the fourth substrate are polymer materials. The optical film according to claim 1, wherein the first substrate includes a first surface facing the second substrate, a light incident surface opposite to the first surface, and a plurality of light incident surfaces. The first microstructure. The optical film according to claim 8, wherein the second substrate includes a second surface facing the first substrate, a light emitting surface opposite to the second surface, and a plurality of first light emitting surfaces on the light emitting surface. Two microstructures. An optical film includes: a first substrate and a second substrate opposite to each other; a third substrate located between the first substrate and the second substrate; a second excitation layer located on the first substrate A substrate and the third substrate include a plurality of second quantum structures. The second quantum structures are quantum dots or quantum rods. The second quantum structures can be excited by a first color light to emit one. A second colored light having a wavelength greater than the wavelength of the first colored light; and a third excitation layer located between the third substrate and the second substrate and including a plurality of third quantum structures, the third quantum structures As quantum dots or quantum rods, the third quantum structures can be excited by the first color light to emit a third color light having a wavelength longer than that of the first color light, and the third color light has a different wavelength from the second color light. The second quantum structure and the third quantum structure are CsPbX ₃ or CH ₃ NH ₃ PbX ₃ , and X is chlorine, bromine, iodine, or any combination thereof. The optical film according to claim 10, wherein a thickness of the second excitation layer and the third excitation layer is 20 μm to 200 μm.