The invention relates to the field of display technology, and particularly to a display device, an optical film and a manufacturing equipment thereof.
Active-type TFT-LCD display devices in recent years have been rapidly developed and widely used, and therefore have become the mainstream display device in the current market. TFT-LCD display panels mainly are classified into three types of panels: TN/STN-type, IPS-type and VA-type. The TN-type LCD display panel is developed early and has mature manufacturing technology, and thus is widely used in small and medium-sized display devices such as personal monitors, digital photo frames and mobile phones.
Compared with the IPS-type and VA-type LCD display panels, the TN-type LCD display panel has high transmittance, mature manufacturing technology and equipment and high yield. However, the TN-type LCD display panel has a grayscale inversion problem and poor viewing angle performance, and therefore generally it needs a viewing angle compensation to enlarge the viewing angle and eliminate the grayscale inversion. In the prior art, a manner of using a compensation film to achieve viewing angle compensation has proposed, and the compensation film generally is integrated with a polarizer together for use; however, because a manufacturing process thereof is complex, for example generally using a discotic liquid crystal material to process an optical film, which would increase the cost of the polarizer.
Except for the compensation film, in the prior art, a commonly-used wide viewing angle film generally uses a scattering method to scatter collimated light rays perpendicularly exited from the LCD display panel to large-angle directions, so as to improve the wide viewing angle effect of the LCD display panel. An operation principle is shown in
A technical problem primarily to be solved by the invention is to provide a display device, an optical film and a manufacturing equipment thereof, which can improve image sharpness while enlarging viewing angle.
In order to solve the technical problem, a technical solution proposed by the invention is to provide an optical film. The optical film includes an optical layer and a base layer. The optical layer includes: a first light-transmissive portion having a light incident surface and a light exit surface parallel with each other, and a plurality of second light-transmissive portions distributed in the first light-transmissive portion. The plurality of light-transmissive portions are through holes penetrating through the first light-transmissive portion and being filled with air, a hole wall of each of the through holes is an inclined surface neither parallel nor perpendicular to the light incident surface of the first light-transmissive portion, two openings of each of the through holes respectively are located on the light incident surface and the light exit surface of the first light-transmissive portion and thereby at least a part of light rays perpendicularly incident from the light incident surface passes through the through hole and exits from the light exit surface so that the at least a part of the light rays perpendicularly incident from the light incident surface does not strike on the inclined surface and exits from the light exit surface. A refractive index of the first light-transmissive portion is different from a refractive index of the air. The base layer is disposed on the light exit surface of the first light-transmissive portion, and a refractive index of the base layer is the same as the refractive index of the first light-transmissive portion.
In an embodiment, each of the through holes is a tapered through hole, the large one of the two openings of the tapered through hole is located on the light exit surface of the first light-transmissive portion, and the small one of the two openings of the tapered through hole is located on the light incident surface of the first light-transmissive portion.
In an embodiment, the refractive index of the first light-transmissive portion is greater than the refractive index of the air.
In order to solve the above technical problem, another technical solution proposed by the invention is to provide a display device. The display device includes a display screen and an optical film. The optical film includes an optical layer. The optical layer includes a first light-transmissive portion and a plurality of second light-transmissive portion. The first light-transmissive portion has a light incident surface and a light exit surface parallel with each other. The light incident surface of the first light-transmissive portion is attached to a display surface of the display screen to receive image light rays of the display screen. The plurality of second light-transmissive portions are distributed in the first light-transmissive portion. The first light-transmissive portion and the plurality of second light-transmissive portions have different refractive indexes, a contact surface of each of the plurality of second light-transmissive portions with the first light-transmissive portion includes an inclined surface neither parallel nor perpendicular to the light incident surface of the first light-transmissive portion, and at least a part of light rays perpendicularly incident from the light incident surface does not strike on the inclined surface and exits from the light exit surface.
In an embodiment, each of the plurality of second light-transmissive portions are through holes penetrating through the first light-transmissive portion and being filled with air, a hole wall of each of the through holes is the inclined surface neither parallel nor perpendicular to the light incident surface of the first light-transmissive portion, two openings of each of the through holes respectively are located on the light incident surface and the light exit surface of the first light-transmissive portion and thereby the at least a part of the light rays perpendicularly incident from the light incident surface passes through the through hole and exits from the light exit surface so that the at least a part of the light rays perpendicularly incident from the light incident surface does not strike on the inclined surface and exits from the light exit surface. The refractive index of the first light-transmissive portion is different from the refractive index of the air.
In an embodiment, each of the through holes is a tapered through hole, the large one of the two openings of the tapered through hole is located on the light exit surface of the first light-transmissive portion, and the small one of the two openings of the tapered through hole is located on the light incident surface of the first light-transmissive portion.
In an embodiment, the refractive index of the first light-transmissive portion is greater than the refractive index of the air.
In an embodiment, the optical film further includes a base layer. The base layer is disposed on the light exit surface of the first light-transmissive portion, and a refractive index of the base layer is the same as the refractive index of the first light-transmissive portion.
In order to solve the above technical problem, still another technical solution proposed by the invention is to provide a manufacturing equipment. The manufacturing equipment includes a first coating mechanism and a transferring mechanism. The first coating mechanism is configured (i.e., structured and arranged) for forming a first light-transmissive portion of an optical layer. The first light-transmissive portion includes a light incident surface and a light exit surface parallel with each other. The transferring mechanism is configured for forming a plurality of second light-transmissive portions in the first light-transmissive portion to thereby form the optical layer of the optical film. The first light-transmissive portion and the plurality of second light-transmissive portions have different refractive indexes, a contact surface of each of the plurality of second light-transmissive portions with the first light-transmissive portion includes an inclined surface neither parallel nor perpendicular to the light incident surface of the first light-transmissive portion, and at least a part of light rays perpendicularly incident from the light incident surface does not strike on the inclined surface and exits from the light exit surface.
In an embodiment, the transferring mechanism is a roller having a plurality of protrusions formed on a surface thereof. The roller is disposed behind the first coating mechanism in a transport direction of the optical layer. During the first light-transmissive portion is transported to the roller, the plurality of protrusions squeeze into the first light-transmissive portion from the light exit surface of the first light-transmissive portion and penetrate through the light incident surface of the first light-transmissive portion to form through holes having the same size and the same shape as the plurality of protrusions in the first light-transmissive portion and thereby form the plurality of second light-transmissive portions. When any one of the plurality of protrusions squeezes into the first light-transmissive portion, a contact surface of the protrusion with the first light-transmissive portion is neither parallel nor perpendicular to the light incident surface of the first light-transmissive portion.
In an embodiment, each of the plurality of protrusions is tapered, and an end of the protrusion near the surface of the roller is larger than another end of the protrusion away from the surface of the roller. During the first light-transmissive portion is transported to the roller, the small end of the protrusion squeezes into the first light-transmissive portion from the light exit surface of the first light-transmissive portion and penetrates through the light incident surface of the first light-transmissive portion.
In an embodiment, the manufacturing equipment further includes a curing mechanism and a base layer transportation mechanism. The curing mechanism is disposed behind the roller in the transport direction of the optical layer and configured for curing the optical layer. The base layer transportation mechanism is disposed behind the curing mechanism in the transport direction of the optical layer and configured for transporting a base layer of the optical film onto the light exit surface of the first light-transmissive portion to thereby form the base layer of the optical film on the light exit surface. A refractive index of the base layer is the same as the refractive index of the first light-transmissive portion.
The efficacy of the invention is that: different from the prior art, in the optical film of the invention, the first light-transmissive portion and the second light-transmissive portions have different refractive indexes and a contact surface of each second light-transmissive portion with the first light-transmissive portion includes an inclined surface neither parallel nor perpendicular to the light incident surface of the first light-transmissive, so that a part of light rays perpendicularly incident from the light incident surface is deflected on the inclined surface, the exit direction of the part of the light rays which originally perpendicularly exits from the light exit surface is changed to be non-perpendicular to the light exit surface, and therefore the purpose of enlarging viewing angle is achieved. In addition, at least a part of the light rays perpendicularly incident from the light incident surface does not strike on the inclined surface, the propagation direction of the at least a part of the light rays would not be deflected, and because the light exit surface and the light incident surface are parallel with each other, the at least a part of the light rays would perpendicularly exit from the light exit surface, and therefore it can reduce image blurriness and improve image sharpness.
In order to more clearly illustrate the technical solutions of various embodiments of the present invention, drawings will be used in the description of embodiments will be given a brief description below. Apparently, the drawings in the following description only are some embodiments of the invention, the ordinary skill in the art can obtain other drawings according to these illustrated drawings without creative effort. In the drawings:
In the following, with reference to accompanying drawings of embodiments of the invention, technical solutions in the embodiments of the invention will be clearly and completely described. Apparently, the embodiments of the invention described below only are a part of embodiments of the invention, but not all embodiments. Based on the described embodiments of the invention, all other embodiments obtained by ordinary skill in the art without creative effort belong to the scope of protection of the invention.
Referring to
The first light-transmissive portion 21 is a base of the optical film and made of an optically transparent organic material, for example is a PET film, TAC or an organic glass and has a thickness in the range of 5 μm˜100 μm, for example 10 μm, 25 μm or 40 μm. Of course, the thickness of the first light-transmissive portion 21 may be in other range e.g., 120 μm˜180 μm, and concretely can be set according to the actual need of product.
The first light-transmissive portion 21 has a light incident surface 211 and a light exit surface 212 parallel with each other.
The second light-transmissive portions 22 and the first light-transmissive portion 21 have different refractive indexes. The second light-transmissive portions 22 may be made of an optically transparent material having a refractive index different from that of the first light-transmissive portion 21. For example, when the first light-transmissive portion 21 is made of a PET (polyethylene terephthalate) material, the second light-transmissive portions 22 may be made of an organic glass having a refractive index different from that of the first light-transmissive portion 21. Of course, the second light-transmissive portions 22 may be air-filled pore structures.
A contact surface of each of the second light-transmissive portions 22 with the first light-transmissive portion 21 includes an inclined surfaces 221 neither parallel nor perpendicular to the light exit surface 211 or the light incident surface 212 of the first light-transmissive portion 21, as shown in
Each neighboring second light-transmissive portions 22 have an interval existed therebetween, so that some of light rays b perpendicularly incident from the light incident surface 211 will pass through between neighboring second light-transmissive portions 22 along the direction perpendicular to the light incident surface 211 or the light exit surface 212 and not strike on the inclined surface 221, and then perpendicularly exits from the light exit surface 212. The interval between neighboring second light-transmissive portions 22 is a region between the neighboring second light-transmissive portions and being not blocked by the inclined surface 221 in a light path that is from the light incident surface 211 to the light exit surface 212 and perpendicular to the light incident surface 211 or the light exit surface 212. By setting the arrangement manner of the second light-transmissive portions 22 in the first light-transmissive portion 21, some of the light rays b perpendicularly incident from the light incident surface 211 can directly pass though between the second light-transmissive portions 22 and does not strike on the inclined surface 221.
As shown in
Of course, in other embodiment, as shown in
Still referring to
Accordingly, in this embodiment, in the light rays perpendicularly incident from the light incident surface 211, only a small part a of the light rays is deflected on the inclined surface 221, most part b of the light rays do not strike on the inclined surface 221 and directly pass through the interval between neighboring second light-transmissive portions 22 and the parallel surfaces 222, 223 of second light-transmissive portion and then exit from the light exit surface 212, the exit angles of the light rays b basically is not deflected and they still exit along the direction perpendicular to the light exit surface 212, which can significantly reduce image blurriness while enlarging viewing angle. In addition, the prior art although can achieve the purpose of enlarging viewing angle by using the microsphere structures to scatter the perpendicularly-incident light rays, the microsphere structures have strong reflection and scattering to the ambient light, it is easy to observe the ambient light reflected by the microsphere structures in all directions, resulting in image whitened and low contrast. Compared with the prior art, in this embodiment, the second light-transmissive portions 22 may cause the reflection of ambient light only on the inclined surface 221, and therefore the reflection of ambient light is weak, which is beneficial to improve the contrast and reduce the phenomenon of image whitened.
Of course, in other embodiment, neighboring second light-transmissive portions may not have the interval existed therebetween, by using the two opposite parallel surfaces of each second light-transmissive portion to make some of perpendicularly incident light rays to perpendicularly exit from the light exit surface, it also can reduce image blurriness.
Referring to
Furthermore, the through hole 52 is a tapered through hole, the large opening 523 of the through hole 52 is located on the light exit surface 512 of the first light-transmissive portion 51, and the small opening 522 is located on the light incident surface of the first light-transmissive portion 51.
Because the refractive index difference between the first light-transmissive portion 51 and the air in the through hole 52, in the light rays perpendicularly incident from the light incident surface 511, the light ray a is refracted when striking on the inclined surface 521 of the through hole 52, an exit angle of the light ray a is enlarged, and therefore the effect of wide viewing angle is achieved. Most of the light rays (e.g., light rays b) directly pass through the through hole 52 (i.e., pass through the through hole 52 from the two openings 522, 523 of the through hole 52) and the interval between neighboring through holes 52 and then perpendicularly exit from the light exit surface 512, so that the light rays b do not strike on the inclined surface 521 and thus perpendicularly exit from the light exit surface, the exit direction of the light rays b basically is not deflected and therefore they still perpendicularly exit from the light exits surface, which is beneficial to reduce image blurriness.
Of course, in other embodiment, each of the through holes may be filled with a transparent optical material having a refractive index different from that of the first light-transmissive portion. Each of the through holes may have other shape, for example, it is a through hole having a right angle trapezoidal cross-sectional shape, i.e., a through hole only has one-sided inclined surface, or the inclined surface of the through hole may be a curved surface instead.
As shown in
An average size of opening of the through holes 52 is in the range of 1 μm˜100μ, and of course, the average size of opening is not limited in the range and can be adjusted to be other size according to actual product.
Referring to
The predetermined value can be determined according to the refractive index of the first light-transmissive portion 121 and thus is not limited herein. The incident angle of the light ray a perpendicularly incident from the light incident surface 1211 on the inclined surface 1221 is relevant with the intersection angle β between the inclined surface 1221 and the light incident surface 1211, by changing the intersection angle β between the inclined surface 1221 of the tapered through hole 122 and the light incident surface 1211, the incident angle of the light ray a on the inclined surface 1221 can be changed correspondingly. The incident angle of the light ray a on the inclined surface 1221 is an intersection angle between the light ray a and the normal line perpendicular to the inclined surface 1221. The smaller the intersection angle β is, the smaller the incident angle of the light ray a on the inclined surface 1221 is. Accordingly, in actual application, it may be that firstly determining the critical angle of total reflection according to the refractive index of the first light-transmissive portion 121 and then setting the size of the intersection angle β according to the critical angle to make the incident angle of the light ray a on the inclined surface 1221 to be larger than the critical angle of total reflection.
In addition, the larger the refractive index of the first light-transmissive portion 121 is, the smaller the critical angle of total reflection on the inclined surface 1221 is, and the total reflection more easily occurs. For example, when the refractive index of the first light-transmissive portion 121 is 1.5, the critical angle of total reflection is 40°, and at this situation, the total reflection would occur when the incident angle of the light ray a on the inclined surface 1221 larger than 40°. When the refractive index of the first light-transmissive portion is 1.6, the critical angle of total reflection is about 37°, and at this situation, the total reflection would occur when the incident angle of the light ray a on the inclined surface 1221 larger than 37°.
Of course, the refractive index of the first light-transmissive portion 121 may be in other range, and can be selected according to the refractive index of the second light-transmissive portions. For example, when the refractive index of the second light-transmissive portions is 1.5, the first light-transmissive portion 121 selects a material having a refractive index larger than 1.5, as long as the total reflection condition can be met.
Referring to
Of course, in other embodiment, for the through holes 132 as shown in
Referring to
The base layer 24 is disposed on the light exit surface 1412 of the first light-transmissive portion 141 and is bonded with the light exit surface 1412 together by adhesive. In this embodiment, each second light-transmissive portion is a tapered through hole 142 penetrating through the first light-transmissive portion 141 and being filled with air, the hole wall of each through hole 142 is an inclined surface 1421 neither parallel nor perpendicular to the light incident surface 1411, and neighboring through holes 142 have an interval existed therebetween. A refractive index of the first light-transmissive portion 141 is greater than the refractive index of the air. A large opening of each through hole 142 is on the light exit surface 1412 of the first light-transmissive portion 141, and a small opening of the through hole 142 is located on the light incident surface 1411 of the first light-transmissive portion 141. An intersection angle between the inclined surface 1421 and the light incident surface 1411 is larger than a predetermined value, so that the light ray a perpendicularly incident from the light incident surface 1411 will generate total reflection on the inclined surface 1421. The light ray a passes through the base layer 24 after total reflection and then generates a secondary refraction at the interface between the base layer 24 and the external air and exits.
By making the light ray a to generate total reflection on the inclined surface 1421 so as to change the exit direction of the light ray a, the exit angle is enlarged when the light ray a exits from the light exit surface 1412, it no longer perpendicularly exits from the light exit surface 1412, so that a better effect of wide viewing angle can be obtained. Moreover, because each of the second light-transmissive portion is the through hole 142 penetrating through the first light-transmissive portion 141 and neighboring second light-transmissive portions have an interval existed therebetween, the light rays b perpendicularly incident from the light incident surface 1411 will pass through the through hole 142 and the interval between neighboring through holes 142 but do not strike on the inclined surface 1421, the exit direction thereof is not changed and thus they perpendicularly exit from the light exit surface 1412, which is beneficial to improve contrast and reduce image whitened whiling reducing image blurriness.
Referring to
Taking the optical film as shown in
Referring to
In addition, at least a part of the light rays perpendicularly incident from the light incident surface does not strike on the inclined surface, the exit direction thereof is not changed and thus it will perpendicularly exit from the light exit surface, and therefore image blurriness can be reduced.
When forming the second light-transmissive portions, by making neighboring second light-transmissive portions to have an interval existed therebetween or the contact surface of each second light-transmissive portion with the first light-transmissive portion to have two opposite parallel surfaces parallel to the light incident surface of the first light-transmissive portion, a part of light rays perpendicularly incident from the light incident surface may directly pass through the interval between neighboring second light-transmissive portions and then exit from the light exit surface, or may pass through the two parallel surfaces of second light-transmissive portion and then exit from the light exit surface, so that the part of the light rays perpendicularly incident from the light incident surface would not strike on the inclined surface of the first light-transmissive portion, the exit direction of the part of the light rays would not be deflected and therefore it can perpendicularly exit from the light exit surface.
Referring to
A release film A1 is used as a transportation belt and configured for supporting the optical film during the process of manufacturing the optical film and playing a protective role. The release film A1 is transported from the first rotation shaft 176 to the second rotation shaft 177. The first coating mechanism 171, the roller 172, the curing mechanism 173, the second coating mechanism 174, the base layer transportation mechanism 175 and the third rotation shaft 178 are located between the first rotation shaft 176 and the second rotation shaft 177.
More specifically, during the manufacturing process, a transport direction of the optical film is from the first rotation shaft 176 to the second rotation shaft 177. In the transport direction of the optical film, the first coating mechanism 171 is located behind the first rotation shaft 176 and configured for coating a transparent optical material on the release film. The transparent optical material may be a PET film material or an organic glass, and so on and used for forming a first light-transmissive portion A2 of an optical layer of the optical film. The roller 172 is located behind the first coating mechanism 171 and has a plurality of protrusions 1721 on a surface thereof. When the first light-transmissive portion A2 of the optical layer is transported to the roller 172, the protrusions 1721 on the roller 172 squeeze into the first light-transmissive portion A2 from the light exit surface of the first light-transmissive portion A2 and penetrate through the light incident surface of the first light-transmissive portion A2 so as to form through holes A3 in the first light-transmissive portion A2 having a same shape and a same size as the protrusions 1721 and thereby the second light-transmissive portions are formed.
A contact surface of each protrusion 1721 with the first light-transmissive portion A2 is neither parallel nor perpendicular to the light incident surface of the first light-transmissive portion A2, so that a hole wall of each formed through hole A3 is neither parallel nor perpendicular to the light incident surface of the first light-transmissive portion A2 and thereby the inclined surface of each second light-transmissive portion is formed.
Furthermore, each protrusion 1721 is tapered, and an end thereof near the surface of the roller 172 is larger than another end thereof away from the surface of the roller 172. When the first light-transmissive portion A2 is transported to the roller 172, the small end of the protrusion 1721 squeezes into the first light-transmissive portion A2 from the light exit surface of the first light-transmissive portion A2 and penetrates through the light incident surface of the first light-transmissive portion A2, and thereby forming a tapered through hole A3 in the first light-transmissive portion A2. The large opening of the tapered through hole A3 is located on the light exit surface of the first light-transmissive portion A2, and the small opening of the tapered through hole A3 is located on the light incident surface of the first light-transmissive portion A2. Accordingly, by transferring the structure of the protrusion 1721 into the first light-transmissive portion A2, the second light-transmissive portions are formed in the first light-transmissive portion A2.
The curing mechanism 173 is disposed behind the roller 172 and configured for curing the first light-transmissive portion A2 formed with the through holes A3 to thereby obtain the optical layer of the optical film. The curing mechanism 173 is a UV (ultraviolet) light curing mechanism and illuminates the first light-transmissive portion A2 with UV light to cure the first light-transmissive portion A2. In other embodiment, the curing mechanism 173 may be a heating mechanism, i.e., curing the first light-transmissive portion A2 by heating.
The base layer transportation mechanism 175 is disposed behind the curing mechanism 173 and can be implemented by a rotation shaft. The base layer transportation mechanism 175 is configured for transporting a base layer A4 onto the cured first light-transmissive portion A2 to form the base layer A4 on the light exit surface of the first light-transmissive portion A2. A material of the base layer A4 is the same as that of the first light-transmissive portion A2, and both are a transparent optical material e.g., a PET film layer or an organic glass. A refractive index of the base layer A4 is the same as that of the first light-transmissive portion A2. Of course, in other embodiment, the refractive index of the base layer may be different from that of the first light-transmissive portion A2.
The second coating mechanism 174 is disposed above the base layer transportation mechanism 175 and configured for coating a pressure-sensitive adhesive on a surface of the base layer A4 going through the base layer transportation mechanism 175 to bond the base layer A4 with the first light-transmissive portion A2 together by the pressure-sensitive adhesive during the base layer A4 is transported onto the first light-transmissive portion A2. In addition, the third rotation shaft 178 is disposed a position of bonding the base layer A4 with the first light-transmissive portion A2 and configured for squeezing the bonded base layer A4 and first light-transmissive portion A2 to tightly press both of them together and thereby obtain the optical film.
In other embodiment, the second coating mechanism 174 can be omitted, and at this situation the base layer A4 and the first light-transmissive portion A2 are bonded together by their own lamination. In addition, in an alternative embodiment, the transferring mechanism may be a mask combination, i.e., forming the optical layer by exposure and development process and so on.
By the manufacturing equipment of this embodiment, the optical layer is formed after the raw material coating (i.e., the process of coating the first light-transmissive portion), structure transferring (i.e., the process of forming the second light-transmissive portions) and UV curing, the base layer and the optical layer then are bonded together by the pressure-sensitive adhesive, the whole manufacturing process is a continuous production process and therefore can greatly improve productivity. Moreover, compared with the exposure and development process, no chemical waste and waste gas are generated, and therefore is more environmentally friendly.
Of course, in other embodiment, the end of each protrusion of the roller near the surface of the roller may be smaller than the other end of the protrusion away from the surface of the roller, so that the large opening of the formed through hole is located on the light incident surface and the small opening of the formed through hole is located on the light exit surface; and each protrusion may be other shaped e.g., a right angle trapezoid.
While the invention has been described in terms of what is presently considered to be the most practical and preferred embodiments, it is to be understood that the invention needs not be limited to the disclosed embodiments. On the contrary, it is intended to cover various modifications and similar arrangements included within the spirit and scope of the appended claims which are to be accorded with the broadest interpretation so as to encompass all such modifications and similar structures.
Number | Date | Country | Kind |
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201410693024.X | Nov 2014 | CN | national |
Filing Document | Filing Date | Country | Kind |
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PCT/CN2014/093264 | 12/8/2014 | WO | 00 |