Compensation film for improving large-viewing-angle display effect and display panel

Abstract

The embodiment of the utility model discloses a compensation film for improving a large-viewing-angle display effect and a display panel. The compensation film comprises a liquid crystal compensation layer, the liquid crystal compensation layer comprises a first liquid crystal compensation part and a second liquid crystal compensation part; the second liquid crystal compensation part is positioned on one side of the first liquid crystal compensation part away from the center of the compensation film; the first liquid crystal compensation part comprises first liquid crystal molecules; the second liquid crystal compensation part comprises second liquid crystal molecules; the included angle between the long-axis direction of the first liquid crystal molecules and the normal of the plane where the compensation film is located is a first included angle alpha; the included angle between the long-axis direction of the second liquid crystal molecules and the normal of the plane where the compensation film is located is a second included angle beta; wherein 0 degree < = alpha < beta < = 90 degrees. By the adoption of the technical scheme, the compensation film can compensate the positive-view-angle light and the large-view-angle light at the same time, and the large-view-angle display effect is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of optical compensation films, and in particular to a compensation film and a display panel for improving a wide viewing angle display effect. Background Art

[0002] With the development of display technology, display panels are widely used in electronic devices such as smart phones, tablet personal computers, car navigation systems, etc., becoming indispensable equipment in people's lives and work.

[0003] Both LCD and LED display panels include multiple film layers. The materials of each film layer have optical anisotropy, which leads to different optical properties in different directions. This will cause different display effects at different viewing angles, especially at large viewing angles, where the display effect is poor.

[0004] Due to the limitation of material properties, it is difficult to realize a film structure that takes into account both the normal viewing angle display effect and the wide viewing angle display effect. Most compensation films in the prior art compensate for the normal direction of the plane where the compensation film is located, and the wide viewing angle display effect is poor. Utility Model Content

[0005] The utility model provides a compensation film and a display panel for improving a wide viewing angle display effect, so that the compensation film can simultaneously compensate for the normal viewing angle light and the wide viewing angle light, thereby improving the wide viewing angle display effect.

[0006] In a first aspect, an embodiment of the utility model provides a compensation film for improving a wide viewing angle display effect, the compensation film comprising a liquid crystal compensation layer;

[0007] The liquid crystal compensation layer includes a first liquid crystal compensation portion and a second liquid crystal compensation portion; the second liquid crystal compensation portion is located on a side of the first liquid crystal compensation portion away from the center of the compensation film;

[0008] The first liquid crystal compensation portion includes first liquid crystal molecules; the second liquid crystal compensation portion includes second liquid crystal molecules;

[0009] The angle between the long axis direction of the first liquid crystal molecule and the normal line of the plane where the compensation film is located is a first angle α; the angle between the long axis direction of the second liquid crystal molecule and the normal line of the plane where the compensation film is located is a second angle β;

[0010] Among them, 0°≤α<β<90°.

[0011] Optionally, the thickness of the liquid crystal compensation layer is D1, 2 μm≤D1≤5 μm.

[0012] Optionally, the in-plane retardation of the liquid crystal compensation layer is Re, 0nm<Re(550nm)≤200nm; the thickness direction retardation of the liquid crystal compensation layer is Rth, -200nm≤Rth(550nm)≤200nm.

[0013] Optionally, the compensation film further includes a polarizer.

[0014] Optionally, the polarizer includes a linear polarizing layer and an in-plane retardation layer.

[0015] Optionally, the linear polarizing layer includes a PVA layer.

[0016] In a second aspect, an embodiment of the utility model further provides a display panel, comprising: a display function layer, and any of the above-mentioned compensation films for improving a wide viewing angle display effect;

[0017] The compensation film is located on the light-emitting side of the display function layer.

[0018] Optionally, the liquid crystal molecules of the liquid crystal compensation layer include a first end close to the display function layer and a second end away from the display function layer;

[0019] Along the first direction, the distance between the first end of the second liquid crystal molecule and the center of the compensation film is L1, and the distance between the second end of the second liquid crystal molecule and the center of the compensation film is L2; ​​the first direction is parallel to the plane where the compensation film is located;

[0020] Among them, L1<L2.

[0021] Optionally, the display panel further includes an adhesive layer;

[0022] The adhesive layer is located between the compensation film and the display function layer.

[0023] The utility model sets a first liquid crystal compensation portion in a liquid crystal compensation layer close to the center so that the first angle between the long axis direction of the first liquid crystal molecule and the normal line is smaller, and a second angle between the long axis direction of the second liquid crystal molecule in a second liquid crystal compensation portion far from the center and the normal line is larger, so that the transmittance of the small viewing angle light in the first liquid crystal compensation portion is larger, and the transmittance of the large viewing angle light in the second liquid crystal compensation portion is also larger, and the small viewing angle optics and the large viewing angle light can be compensated at the same time. When applied to a display panel, both the normal viewing angle display effect and the large viewing angle display effect can be taken into account to improve the large viewing angle display effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a schematic diagram of the structure of a compensation film provided by an embodiment of the utility model;

[0025] Figure 2This is a schematic diagram of the structure of another compensation film provided by an embodiment of the utility model;

[0026] Figure 3 This is a schematic diagram of the structure of another compensation film provided by an embodiment of the utility model;

[0027] Figure 4 This is a schematic diagram of the structure of another compensation film provided by an embodiment of the utility model;

[0028] Figure 5 It is a structural schematic diagram of a display panel provided by an embodiment of the utility model;

[0029] Figure 6 This is a structural schematic diagram of another display panel provided by an embodiment of the utility model. DETAILED DESCRIPTION

[0030] The present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the present invention, rather than to limit the present invention. It should also be noted that, for ease of description, only the parts related to the present invention, rather than all structures, are shown in the accompanying drawings.

[0031] In order to solve the above technical problems, an embodiment of the utility model provides a compensation film for improving the wide-viewing angle display effect, the compensation film comprising a liquid crystal compensation layer; the liquid crystal compensation layer comprising a first liquid crystal compensation portion and a second liquid crystal compensation portion; the second liquid crystal compensation portion is located on a side of the first liquid crystal compensation portion away from the center of the compensation film; the first liquid crystal compensation portion comprises a first liquid crystal molecule; the second liquid crystal compensation portion comprises a second liquid crystal molecule; the angle between the long axis direction of the first liquid crystal molecule and the normal to the plane where the compensation film is located is a first angle α; the angle between the long axis direction of the second liquid crystal molecule and the normal to the plane where the compensation film is located is a second angle β; wherein, 0°≤α<β<90°.

[0032] By adopting the above technical scheme, by setting the first angle between the long axis direction of the first liquid crystal molecule in the first liquid crystal compensation part close to the center of the liquid crystal compensation layer and the normal line to be smaller, and the second angle between the long axis direction of the second liquid crystal molecule in the second liquid crystal compensation part far from the center and the normal line to be larger, the transmittance of the small viewing angle light in the first liquid crystal compensation part is larger, and the transmittance of the large viewing angle light in the second liquid crystal compensation part is also larger, which can simultaneously compensate for the small viewing angle optics and the large viewing angle light. When applied to a display panel, it can take into account both the normal viewing angle display effect and the large viewing angle display effect to improve the large viewing angle display effect.

[0033] The above is the core idea of ​​this application. The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of them. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0034] The terms used in the embodiments of the present invention are only for the purpose of describing specific embodiments, and are not intended to limit the present invention. It should be noted that the directional words such as "upper", "lower", "left", "right" and the like described in the embodiments of the present invention are described at the angles shown in the accompanying drawings and should not be understood as limitations on the embodiments of the present invention. In addition, in the context, it is also necessary to understand that when it is mentioned that an element is formed "on" or "under" another element, it can not only be directly formed "on" or "under" another element, but also indirectly formed "on" or "under" another element through an intermediate element. The terms "first", "second" and the like are only used for descriptive purposes and do not represent any order, quantity or importance, but are only used to distinguish different components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to the specific circumstances.

[0035] Figure 1 This is a schematic diagram of the structure of a compensation film provided by an embodiment of the utility model, referring to Figure 1 The compensation film 001 includes a liquid crystal compensation layer 10, and the liquid crystal compensation layer 10 includes a first liquid crystal compensation portion 11 and a second liquid crystal compensation portion 12. The second liquid crystal compensation portion 12 is located on a side of the first liquid crystal compensation portion 11 away from the center of the compensation film 001. The first liquid crystal compensation portion 11 includes a first liquid crystal molecule 101, and the second liquid crystal compensation portion 12 includes a second liquid crystal molecule 102. The long axis direction of the first liquid crystal molecule 101 forms an angle with a normal line T of the plane where the compensation film 001 is located, and the long axis direction of the second liquid crystal molecule 102 forms an angle with a normal line T of the plane where the compensation film 001 is located, and the long axis direction of the second liquid crystal molecule 102 forms an angle with a second angle β, wherein 0°≤α<β<90°.

[0036] Specifically, the refractive index of the liquid crystal molecules in the liquid crystal compensation layer 10 in the long axis direction is different from the refractive index in the short axis direction, and the transmittance of the light parallel to the long axis direction of the liquid crystal molecules passing through the liquid crystal molecules is the largest, and the transmittance of the light parallel to the short axis direction of the liquid crystal molecules passing through the liquid crystal molecules is the smallest. The first angle α between the long axis direction of the first liquid crystal molecules 101 in the first liquid crystal compensation part 11 and the normal line T of the plane where the compensation film 001 is located is small, so that the transmittance of the light with a smaller viewing angle close to the normal line T direction when passing through the compensation film 001 in the central area is large; the second angle β between the long axis direction of the second liquid crystal molecules 102 in the second liquid crystal compensation part 12 and the normal line T of the plane where the compensation film 001 is located is large, so that the transmittance of the light with a larger viewing angle away from the normal line T direction when passing through the compensation film 001 in the edge area is large. In this way, the compensation film 001 can simultaneously compensate for the optical and light with a small viewing angle, and when applied to a display panel, it can improve the display effect of a large viewing angle.

[0037] For example, a polymer film such as polyethylene terephthalate (PET), polymethyl methacrylate (PMMA), polycarbonate (PC), triacetyl cellulose (TAC), cycloolefin polymer (COP), copolymers of cycloolefin (COC) can be formed as a liquid crystal protective film (not shown in the figure) of the liquid crystal compensation layer 10, and the thickness of the liquid crystal protective film is in the range of 20 to 200 um. Then, a liquid liquid crystal compensation layer 10 is coated on one side of the liquid crystal protective film, and placed in an oven for drying at a temperature of 40-150°C for a time of 10-1000 seconds to obtain a solid liquid crystal compensation layer 10. It should be noted that when the liquid crystal compensation layer 10 needs to be laminated with other film layers, the liquid crystal protective film needs to be peeled off after the liquid crystal compensation layer 10 is laminated, and the peeling force at 180° is 0 to 50 gf / 25 mm.

[0038] In other optional embodiments, the liquid crystal compensation layer 10 may also be directly formed on the film layer to be bonded, so as to reduce the process steps and lower the cost.

[0039] Before solidifying the liquid crystal compensation layer 10, electrodes may be arranged on one or both sides of the first liquid crystal compensation part 11 to form a first electromagnetic field, and electrodes may be arranged on one or both sides of the second liquid crystal compensation part 12 to form a second electromagnetic field (not shown in the figure), so that the first liquid crystal molecules 101 of the first liquid crystal compensation part 11 are in the first electromagnetic field for a certain period of time and are converted into a polarized state, that is, the angle between the long axis direction of the first liquid crystal molecules 101 and the normal line T of the plane where the compensation film 001 is located is maintained at a first angle α; similarly, the second liquid crystal molecules 102 of the second liquid crystal compensation part 12 are in the second electromagnetic field for a certain period of time and are converted into a polarized state, that is, the angle between the long axis direction of the second liquid crystal molecules 102 and the normal line T of the plane where the compensation film 001 is located is maintained at a second angle β. Then, the electrodes on one or both sides of the first liquid crystal compensation part 11 and the electrodes on one or both sides of the second liquid crystal compensation part 12 are removed, and the liquid crystal compensation layer 10 is solidified to form the liquid crystal compensation layer 10 provided by the embodiment of the utility model.

[0040] The compensation film for improving the wide-viewing angle display effect provided by the embodiment of the utility model is configured such that the first angle between the long axis direction of the first liquid crystal molecule in the first liquid crystal compensation part close to the center of the liquid crystal compensation layer and the normal line is smaller, and the second angle between the long axis direction of the second liquid crystal molecule in the second liquid crystal compensation part far from the center and the normal line is larger, so that the transmittance of the small-viewing angle light in the first liquid crystal compensation part is larger, and the transmittance of the large-viewing angle light in the second liquid crystal compensation part is also larger, and the optical and light of the small-viewing angle can be compensated at the same time. When applied to a display panel, both the normal-viewing angle display effect and the wide-viewing angle display effect can be taken into account to improve the wide-viewing angle display effect.

[0041] Optional, reference Figure 2 The thickness of the liquid crystal compensation layer 10 is D1, 2μm≤D1≤5μm. This setting can increase the transmittance of light and reduce the scattering of light in the liquid crystal compensation layer 10, so that the transmittance of light is ≥90% and the haze is ≤1%.

[0042] Optionally, the in-plane retardation of the liquid crystal compensation layer 10 is Re, 0 nm ≤ Re (550 nm) ≤ 200 nm; the thickness direction retardation of the liquid crystal compensation layer 10 is Rth, -200 nm ≤ Rth (550 nm) ≤ 200 nm.

[0043] Among them, the in-plane delay Re (550nm) refers to the phase delay of 550nm light in the process of propagating inside the liquid crystal compensation layer 10. The size of the in-plane delay Re will affect the phase change of the light, and then affect the propagation direction and interference effect of the light. The larger the in-plane delay Re, the more obvious the phase change of the light. In one embodiment, the in-plane delay Re of the second liquid crystal compensation part 12 is greater than the in-plane delay Re of the first liquid crystal compensation part 11, so that the phase change of the light in the second liquid crystal compensation part 12 is greater than the phase change of the light in the first liquid crystal compensation part 11. When applied to a display panel, a display effect of compensating a large viewing angle is achieved.

[0044] The thickness direction delay Rth (550nm) refers to the phase delay of 550nm light in the thickness direction of the liquid crystal compensation layer 10. The thickness direction delay Rth will affect the diffraction and reflection of the light. It is unreasonable to be too large or too small. In an optional embodiment, the thickness direction delay Rth (550nm) of the liquid crystal compensation layer 10 ranges from -150 to -50nm, and 50 to 150nm to compensate for the wide viewing angle light.

[0045] Optional, Figure 3 This is a schematic diagram of the structure of another compensation film provided by the embodiment of the utility model, referring to Figure 3 , the compensation film 001 also includes a polarizer 20 .

[0046] Specifically, the polarizer 20 can selectively transmit light in a specific direction. The polarizer 20 can also convert non-polarized light into polarized light, or polarized light into non-polarized light. It selectively transmits polarized light in a specific direction, thereby improving the display effect when applied to a display panel.

[0047] It should be noted that, when applied to a display panel, the polarizer 20 can be located on a side of the compensation film 001 close to the display panel, or on a side of the compensation film 001 far from the display panel, which is not specifically limited in the embodiment of the utility model.

[0048] Optional, Figure 4 This is a schematic diagram of the structure of another compensation film provided by the embodiment of the utility model, referring to Figure 4 The polarizer 20 includes a linear polarizing layer 21 and an in-plane retardation layer 22 .

[0049] The linear polarizing layer 21 includes a polyvinyl alcohol (PVA) layer, dichroic ions, boric acid, etc., wherein the PVA layer can be used as a dispersion carrier of dichroic ions, and the linear polarizing layer 21 has a polarizing function, and can selectively transmit or absorb polarized light in a specific direction, and convert non-polarized light into polarized light; the in-plane retardation layer 22 includes a polymer film such as PC, COP, COC, etc., and the in-plane retardation layer 22 provides in-plane retardation, which can adjust the phase delay of the light, and affect the phase change and propagation direction of the light. The linear polarizing layer 21 and the in-plane retardation layer 22 work together to achieve control of the polarization state and phase of the light, adjust the polarization state and phase delay of the light, and achieve normal viewing angle display.

[0050] Illustratively, a polymer film such as PET, PMMA, PC, TAC, COP, COC, etc. can be first formed as an in-plane retardation layer 22, a linear polarizing layer 21 can be formed on one side of the in-plane retardation layer 22, and an optical alignment layer can be formed on the other side of the in-plane retardation layer 22, and then a liquid crystal compensation layer 10 can be formed on the surface of the alignment layer to form a compensation film 001.

[0051] It should be noted that the figure only exemplarily shows that the in-plane retardation layer is located between the linear polarizing layer and the liquid crystal compensation layer. In other feasible embodiments, the liquid crystal compensation layer may also be arranged between the linear polarizing layer and the in-plane retardation layer (not shown in the figure).

[0052] Based on the above concept, the embodiment of the utility model further provides a display panel, Figure 5 is a schematic diagram of the structure of a display panel provided by an embodiment of the utility model, referring to Figure 5 The display panel 002 includes: a display function layer 30, and a compensation film 001 for improving light with a wide viewing angle provided by any embodiment of the utility model, wherein the compensation film 001 is located on the light-emitting side of the display function layer.

[0053] The display panel 002 includes but is not limited to an LED display panel and an LCD display panel.

[0054] Specifically, the compensation film 001 can simultaneously compensate for the optical effects of a small viewing angle and the light effects of a large viewing angle, thereby improving the display effect of the display panel 002. The display panel 002 includes any of the compensation films 001 described above, so that the display panel 002 has corresponding functions and beneficial effects.

[0055] Optional, continue to refer to Figure 5The liquid crystal molecules of the liquid crystal compensation layer 10 include a first end A close to the display function layer 30 and a second end B away from the display function layer 30; along the first direction X, the distance between the first end A of the second liquid crystal molecule 102 and the center O' of the compensation film 001 is L1, and the distance between the second end B of the second liquid crystal molecule 102 and the center O' of the compensation film 001 is L2; ​​the first direction X is parallel to the plane where the compensation film 001 is located; wherein, L1<L2.

[0056] Specifically, compared to the second end B of the second liquid crystal molecule 102, the first end A of the second liquid crystal molecule 102 is inclined in the direction away from the center O' of the compensation film 001, that is, along the light emitting direction of the display panel 002, the long axis of the second liquid crystal molecule 102 diverges in the direction away from the center O'. In this way, the angle between the wide-viewing angle light and the long axis direction of the second liquid crystal molecule 102 can be smaller, which is beneficial to increase the transmittance of the wide-viewing angle light in the second liquid crystal compensation part 12 and improve the wide-viewing angle display effect.

[0057] Optional, Figure 6 is a schematic diagram of the structure of another display panel provided by the embodiment of the utility model, referring to Figure 6 The display panel 002 further includes an adhesive layer 40 , and the adhesive layer 40 is located between the compensation film 001 and the display function layer 30 .

[0058] Specifically, the compensation film 001 and the display function layer 30 can be bonded by an adhesive layer 40, and the adhesive layer 40 includes but is not limited to water-based glue (such as PVA water glue), polyurethane glue, epoxy glue, acrylic adhesive, polyisocyanate, alkyd resin, chloroprene rubber, styrene-butadiene rubber, cyano rubber, silicone, etc.

[0059] In one embodiment, the thickness of the adhesive layer 40 is in the range of 0.1-100 um, and can be cured by heating, light curing, or the like.

[0060] Note that the above are only preferred embodiments of the present invention and the technical principles used. Those skilled in the art will understand that the present invention is not limited to the specific embodiments herein, and that various obvious changes, readjustments, combinations and substitutions can be made by those skilled in the art without departing from the scope of protection of the present invention. Therefore, although the present invention is described in more detail through the above embodiments, the present invention is not limited to the above embodiments, and may include more other equivalent embodiments without departing from the concept of the present invention, and the scope of the present invention is determined by the scope of the appended claims.

Claims

1. A compensation film for improving the display effect of a wide viewing angle, characterized in that: The compensation film includes a liquid crystal compensation layer; The liquid crystal compensation layer includes a first liquid crystal compensation portion and a second liquid crystal compensation portion; the second liquid crystal compensation portion is located on a side of the first liquid crystal compensation portion away from the center of the compensation film; The first liquid crystal compensation portion includes first liquid crystal molecules; the second liquid crystal compensation portion includes second liquid crystal molecules; The angle between the long axis direction of the first liquid crystal molecule and the normal line of the plane where the compensation film is located is a first angle α; the angle between the long axis direction of the second liquid crystal molecule and the normal line of the plane where the compensation film is located is a second angle β; Among them, 0°≤α<β<90°.

2. The compensation film for improving the display effect with a wide viewing angle according to claim 1, characterized in that: The thickness of the liquid crystal compensation layer is D1, 2 μm≤D1≤5 μm.

3. The compensation film for improving the display effect with a wide viewing angle according to claim 1, characterized in that: The in-plane retardation of the liquid crystal compensation layer is Re, 0nm<Re(550nm)≤200nm; the thickness direction retardation of the liquid crystal compensation layer is Rth, -200nm≤Rth(550nm)≤200nm.

4. The compensation film for improving the display effect with a wide viewing angle according to claim 1, characterized in that: The compensation film also includes a polarizer.

5. The compensation film for improving the display effect with a wide viewing angle according to claim 4, characterized in that: The polarizer includes a linear polarizing layer and an in-plane retardation layer.

6. The compensation film for improving the display effect with a wide viewing angle according to claim 5, characterized in that: The linear polarizing layer includes a PVA layer.

7. A display panel, characterized in that: include: A display function layer, and a compensation film for improving a wide viewing angle display effect as described in any one of claims 1 to 6; The compensation film is located on the light-emitting side of the display function layer.

8. The display panel according to claim 7, characterized in that: The liquid crystal molecules of the liquid crystal compensation layer include a first end close to the display function layer and a second end away from the display function layer; Along the first direction, the distance between the first end of the second liquid crystal molecule and the center of the compensation film is L1, and the distance between the second end of the second liquid crystal molecule and the center of the compensation film is L2; ​​the first direction is parallel to the plane where the compensation film is located; Among them, L1<L2.

9. The display panel according to claim 7, characterized in that: The display panel further includes an adhesive layer; The adhesive layer is located between the compensation film and the display function layer.

Images