TW202503385A - Backlight device and display device - Google Patents

Abstract

A backlight device is provided. The backlight device includes: a substrate, a lighting component, a first optical film, a second optical film, and a third optical film. The lighting component is disposed on the substrate. The first optical film is disposed on the substrate, and includes a first prism structure extending along a first direction. The second optical film is disposed on the first optical film, and includes a second prism structure extending along a second direction. The third optical film is disposed on the second optical film, and includes a third prism structure extending along a third direction. Wherein, an included angle between the first direction and the second direction is substantially in a range between 30 degree to 150 degree, and the second direction is substantially parallel to the third direction.

Description

Backlight device and display device

The present disclosure relates to an improvement of a backlight device of a display device.

Nowadays, most electronic devices are made with more concentrated light sources by attaching anti-penetration films to electronic devices to achieve privacy. However, the above methods still have disadvantages such as high energy consumption, high cost or low yield. In addition, current electronic devices still cannot have both high contrast and low side lobe light intensity, or have poor light package stability (that is, the assembly error tolerance of optical films is low).

Therefore, a new display device and backlight device are needed to improve the above problems.

The present disclosure provides a backlight device, comprising a substrate, a light-emitting element, a first optical film, a second optical film and a third optical film. The light-emitting element is disposed on the substrate to provide a light source. The first optical film is disposed on the substrate, and comprises a first prism structure extending along a first direction. The second optical film is disposed on the first optical film, and comprises a second prism structure extending along a second direction. The third optical film is disposed on the second optical film, and comprises a third prism structure extending along a third direction. The angle between the first direction and the second direction is substantially between 30 degrees and 150 degrees, and the second direction is substantially parallel to the third direction.

The present disclosure further provides a display device, comprising a backlight device and a display panel. The backlight device comprises a substrate, a light-emitting element, a first optical film, a second optical film and a third optical film. The light-emitting element is disposed on the substrate to provide a light source. The first optical film is disposed on the substrate, and comprises a first prism structure extending along a first direction. The second optical film is disposed on the first optical film, and comprises a second prism structure extending along a second direction. The third optical film is disposed on the second optical film, and comprises a third prism structure extending along a third direction. The angle between the first direction and the second direction is substantially between 30 degrees and 150 degrees, and the second direction is substantially parallel to the third direction. The display panel is disposed on the backlight device.

Reference will be made in detail to exemplary embodiments of the present disclosure, examples of which are illustrated in the accompanying drawings. Whenever possible, the same reference numerals are used in the drawings and description to represent the same or similar parts.

Certain terms are used throughout the specification and claims to refer to specific components. Those skilled in the art will appreciate that manufacturers of sensing devices may refer to the same component by different names. This document does not intend to distinguish between components that have the same function but different names. In the following specification and claims, the words "including", "comprising" and "comprising" are open-ended words and should be interpreted as "including but not limited to..."

Directional terms such as "up", "down", "front", "back", "left", "right", etc., mentioned herein are only with reference to the directions of the accompanying drawings. Therefore, the directional terms used are used to illustrate, but not to limit the present disclosure. In the accompanying drawings, each diagram depicts the general characteristics of the methods, structures and/or materials used in a particular embodiment. However, these diagrams should not be interpreted as defining or limiting the scope or nature covered by these embodiments. For example, for the sake of clarity, the relative size, thickness and position of each film layer, region and/or structure may be reduced or exaggerated.

A structure (or layer, component, substrate) described in the present disclosure is located on/above another structure (or layer, component, substrate), which may mean that the two structures are adjacent and directly connected, or may mean that the two structures are adjacent but not directly connected. Indirect connection means that there is at least one intermediate structure (or intermediate layer, intermediate component, intermediate substrate, intermediate spacer) between the two structures, the lower surface of one structure is adjacent to or directly connected to the upper surface of the intermediate structure, and the upper surface of the other structure is adjacent to or directly connected to the lower surface of the intermediate structure. The intermediate structure can be a single-layer or multi-layer physical structure or a non-physical structure, without limitation. In the present disclosure, when a certain structure is disposed "on" another structure, it may mean that the certain structure is "directly" on the other structure, or it may mean that the certain structure is "indirectly" on the other structure, that is, at least one structure is sandwiched between the certain structure and the other structure.

The terms "approximately," "substantially," or "substantially" are generally interpreted as being within 10% of a given value or range, or within 5%, 3%, 2%, 1% or 0.5% of a given value or range.

Furthermore, any two values or directions used for comparison may have a certain error. If the first direction is perpendicular or "approximately" perpendicular to the second direction, the angle between the first direction and the second direction may be between 80 and 100 degrees; if the first direction is parallel or "approximately" parallel to the second direction, the angle between the first direction and the second direction may be between 0 and 10 degrees.

The ordinal numbers used in the specification and claim, such as "first", "second", etc., are used to modify the components. They do not imply or represent any previous ordinal number of the component (or components), nor do they represent the order of one component to another component, or the order of the manufacturing method. The use of these ordinal numbers is only used to make a component with a certain name clearly distinguishable from another component with the same name. The claim and the specification may not use the same terms, and accordingly, the first component in the specification may be the second component in the claim.

In the present disclosure, the phrases “a given range is from a first value to a second value”, “a given range falls within the range from a first value to a second value” mean that the given range includes the first value, the second value and other values therebetween.

It should be understood that according to the embodiments of the present disclosure, an optical microscope (OM), a scanning electron microscope (SEM), a thin film thickness profiler (α-step), an elliptical thickness gauge, or other suitable methods may be used to measure the depth, thickness, width, or height of each component, or the spacing or distance between components. According to some embodiments, a scanning electron microscope may be used to obtain a cross-sectional structural image including the components to be measured, and measure the depth, thickness, width, or height of each component, or the spacing or distance between components.

In addition, the display device disclosed in the present disclosure can be applied to electronic devices, and the electronic devices may include imaging devices, assembly devices, backlight devices, antenna devices, splicing devices, touch electronic devices (touch display), curved electronic devices (curved display) or non-rectangular electronic devices (free shape display), but are not limited thereto. When the electronic device is an assembly device or a splicing device, the electronic device may include a gripping mechanism, but is not limited thereto. The electronic device may, for example, include liquid crystal, light emitting diode, fluorescence, phosphor, other suitable display media, or a combination of the foregoing, but is not limited thereto. The display device may be a non-self-luminous display device or a self-luminous display device. The antenna device may be a liquid crystal type antenna device or a non-liquid crystal type antenna device, and the sensing device may be a sensing device for sensing capacitance, light, heat or ultrasound, but is not limited thereto. The splicing device may be, for example, a display splicing device or an antenna splicing device, but is not limited thereto. It should be noted that the electronic device may be any arrangement or combination of the aforementioned, but is not limited thereto. In addition, the electronic device may be a bendable or flexible electronic device. It should be noted that the electronic device may be any arrangement or combination of the aforementioned, but is not limited thereto. In addition, the appearance of the electronic device may be rectangular, circular, polygonal, a shape with curved edges, or other suitable shapes. The electronic device may have peripheral systems such as a drive system, a control system, a light source system, a shelf system, etc. to support the display device, the antenna device or the splicing device.

It should be noted that the following embodiments can replace, reorganize, and mix the features of several different embodiments to complete other embodiments without departing from the spirit of the present disclosure. The features of each embodiment can be mixed and matched as long as they do not violate the spirit of the invention or conflict with each other.

Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by a person skilled in the art to which the present disclosure belongs. It is understood that these terms, such as terms defined in commonly used dictionaries, should be interpreted as having a meaning consistent with the background or context of the relevant technology and the present disclosure, and should not be interpreted in an idealized or overly formal manner unless specifically defined in the present disclosure embodiments.

In addition, words such as "adjacent" in the description and claims are used to describe proximity, not necessarily contact.

In addition, the descriptions of "when..." or "when..." in this disclosure indicate "at the moment, before or after", etc., and are not limited to the situation of happening at the same time, which is explained in advance. The descriptions of "disposed on..." and the like in this disclosure indicate the corresponding position relationship of two elements, and do not limit whether the two elements are in contact, unless there is a special limitation, which is explained in advance. Furthermore, when this disclosure records multiple effects, if the word "or" is used between the effects, it means that the effects can exist independently, but does not exclude that multiple effects can exist at the same time.

FIG. 1A is a schematic cross-sectional view of a display device according to an embodiment of the present disclosure. FIG. 1B is a three-dimensional view of a display device according to an embodiment of the present disclosure. It should be noted that FIG. 1B removes some components (substrate 10) in FIG. 1A to make the features of other components more obvious. In addition, relative relationships such as "top", "bottom", "above" or "below" of components hereinafter refer to relative positions in the Z direction. In addition, it should be noted that the description of "an object disposed on another object" in this article may indicate that the object is disposed at a certain position of the other object, and does not mean that the object must be disposed above the other object.

As shown in FIGS. 1A and 1B , the display device 1 of the present disclosure may include a display panel 100 and a backlight device 200, and the display panel 100 may be disposed on the backlight device 200. The backlight device 200 may include a substrate 10, a light-emitting element 20, a first optical film 11, a second optical film 12, and a third optical film 13. In a normal direction (e.g., Z direction) of the substrate 10, the light-emitting element 20 is disposed on the substrate 10, the first optical film 11 is disposed on the substrate 10, the second optical film 12 is disposed on the first optical film 11, and the third optical film 13 is disposed on the second optical film 12.

The light-emitting element 20 is used to provide a light source. The light-emitting element 20 may include at least one photonic sub-unit 21; for the convenience of explanation, the following is an example in which the light-emitting element 20 includes a plurality of photonic sub-units 21, wherein the plurality of photonic sub-units 21 may be arranged, for example, along the Y direction, and the Y direction is perpendicular to the Z direction. The first optical film 11 includes a first prism structure 111, wherein the first prism structure 111 extends along a first direction D1, wherein the first direction D1 may be parallel to the Y direction, or may be substantially parallel to the Y direction. The second optical film 12 includes a second prism structure 121, wherein the second prism structure 121 extends along a second direction D2. The third optical film 13 includes a third prism structure 131, wherein the third prism structure 131 extends along a third direction D3. In more detail, the first prism structure 111 may include a plurality of first strip structures 111a, each of which extends in a direction D1. The second prism structure 121 includes a plurality of second strip structures 121a, each of which extends in a second direction D2. The third prism structure 131 includes a plurality of third strip structures 131a, each of which extends in a third direction D3. The first direction D1, the second direction D2, and the third direction D3 may each be perpendicular to the Z direction, but are not limited thereto. In addition, the first direction D1, the second direction D2, and the third direction D3 may be located on the same horizontal plane (e.g., an XY plane), but are not limited thereto.

In one embodiment, the first direction D1 and the second direction D2 may have an angle θ12 between them (as shown in FIG. 1B ). In one embodiment, the angle θ12 may be substantially between positive and negative 30 degrees and 90 degrees, that is, the angle θ12 may be between 30 degrees and 150 degrees (that is, 30 ^° ≦θ12≦150 ^° ), but is not limited thereto. In one embodiment, the angle θ12 may be substantially between positive and negative 45 degrees and 90 degrees, that is, the angle θ12 may be between 45 degrees and 150 degrees (that is, 45 ^° ≦θ12≦150 ^° ), but is not limited thereto. In one embodiment, the angle θ12 may be substantially between positive and negative 60 degrees and 90 degrees, that is, the angle θ12 may be between 60 degrees and 120 degrees (that is, 60 ^° ≦θ12≦120 ^° ), but is not limited thereto. In addition, in one embodiment, the second direction D2 and the third direction D3 may be substantially parallel.

In one embodiment, in the normal direction (Z) of the substrate 10, the tip portions (e.g., the narrower end) of the first prism structure 111 and the second prism structure 121 may face the same direction, for example, the first prism structure 111 and the second prism structure 121 may face the substrate 10, but not limited thereto. The third prism structure 131 and the second prism structure 121 may face opposite directions, for example, the third prism structure 131 may face the display panel 100, but not limited thereto. In more detail, the first prism structure 111 may have a first bottom plate 112, and the first strip structure 111a is disposed on the first bottom plate 112. The second prism structure 121 may have a second bottom plate 122, and the second strip structure 121a is disposed on the second bottom plate 122. The third prism structure 131 may have a third bottom plate 132, and the third strip structure 131a is disposed on the third bottom plate 132. Here, “the first prism structure 111 faces the substrate 10” means that the first strip structure 111a is closer to the substrate 10 than the first bottom plate 112, the second prism structure 121 faces the substrate 10 means that the second strip structure 121a is closer to the substrate 10 than the second bottom plate 122, and the third prism structure 131 faces the display panel 100 means that the third strip structure 131a is closer to the display panel 100 than the third bottom plate 132.

The display device 1 of the present disclosure can provide a high contrast effect by configuring the first prism structure 111, the second prism structure 121, and the third prism structure 131. Alternatively, the light emitted by the backlight device 200 can be concentrated toward the normal viewing angle, and the privacy requirement can be met without additionally attaching or installing an anti-penetration film or using a collimating backlight module with low yield and/or high cost, or the side view light intensity can be reduced.

Next, the characteristics of each component are described.

First, the display panel 100 is described. In the present disclosure, although not shown in detail, the display panel 100 may include upper and lower substrates, a display unit, a seal, an alignment film, a polarizing plate, a light shielding layer, a color filter layer and/or a driving element, but is not limited thereto.

Next, the substrate 10 of the backlight device 200 is described. The substrate 10 may be, for example, a substrate, a frame or a housing, and may have conductive or insulating properties, but is not limited thereto. In one embodiment, the substrate 10 may be, for example, a frame or a housing including iron parts, but is not limited thereto. In one embodiment, when the substrate 10 is a frame or a housing, the substrate 10 may also have a side portion, and the side portion may extend along the normal direction (Z) to be adjacent to the light-emitting element 20, the first optical film 11, the second optical film 12, and the third optical film 13, but is not limited thereto. In one embodiment, the substrate 10 may include a plane 10a, and the light-emitting element 20, the first optical film 11, the second optical film 12, and the third optical film 13 may be directly or indirectly located on the plane 10a; for example, in one embodiment, the backlight device 200 may further include a circuit board 50 (such as but not limited to a flexible circuit board), wherein the circuit board 50 may be located on the plane 10a, and the light-emitting element 20 may be located on the circuit board 50, but not limited thereto. In one embodiment, a glue 60 (which may be various types of glue) may be disposed between the light-emitting element 20 and the substrate 10, but not limited thereto.

Next, the light-emitting element 20 of the backlight device 200 is described. In one embodiment, the type of the light-emitting subunit 21 of the light-emitting element 20 may include a light-emitting diode, which may include, for example, an organic light-emitting diode (OLED), a sub-millimeter light-emitting diode (mini LED), a micro LED, or a quantum dot light-emitting diode (quantum dot LED, which may include QLED, QDLED), fluorescence, phosphor, or other suitable materials, or a combination thereof, but is not limited thereto.

Next, the first optical film 11, the second optical film 12, and the third optical film 13 of the backlight device 200 are described. In one embodiment, the first optical film 11 and the second optical film 12 are in contact with each other, and the second optical film 12 and the third optical film 13 are in contact with each other. In another embodiment, the first optical film 11 and the second optical film 12 are in contact with each other, while the second optical film 12 and the third optical film 13 are not in contact, or the first optical film 11 and the second optical film 12 are not in contact, while the second optical film 12 and the third optical film 13 are in contact with each other. In one embodiment, when the first optical film 11 and the second optical film 12 are not in contact, a glue material may be disposed between the first optical film 11 and the second optical film 12, or when the second optical film 12 and the third optical film 13 are not in contact, a glue material may be disposed between the second optical film 12 and the third optical film 13, and the glue material here may be, for example, an optical glue material, but may also be other types of glue materials.

In one embodiment, the backlight device 200 further includes a light guide element 30, which is disposed adjacent to the light emitting element 20. The light guide element 30 may be disposed on the substrate 10 in the normal direction (Z) of the substrate 10. In one embodiment, the light emitting element 20 may be, for example, disposed on one side of the light incident surface of the light guide element 30. In one embodiment, the light guide element 30 may be, for example, a light guide plate, but is not limited thereto.

In one embodiment, the backlight device 200 further includes a reflective element 40. In the normal direction (Z) of the substrate 10, the reflective element 40 can be disposed between the substrate 10 and the light-guiding element 30. In one embodiment, the reflective element 40 can be used to reflect the light emitted from the bottom of the light-guiding element 30, so that the light travels toward the display panel 100 to improve the utilization rate of the light. In one embodiment, the material of the reflective element 40 is not particularly limited, for example, it can include but is not limited to metal, white ink, other reflective materials or a combination thereof. Among them, the metal can include gold, silver, copper, aluminum or a combination thereof, but is not limited thereto; the white ink can include white polyimide, resin or a combination thereof, but is not limited thereto. In addition, the reflective element 40 can include a single-layer or multi-layer film reflector. The present disclosure is not limited thereto. In one embodiment, the circuit board 50 and the reflective element 40 may be connected together via an adhesive 60, but the present invention is not limited thereto.

Next, the detailed structures of the first optical film 11, the second optical film 12, and the third optical film 13 of the present disclosure are described with reference to FIGS. 2A to 4B, and FIGS. 1A and 1B are used as references.

FIG. 2A is a three-dimensional schematic diagram of a first optical film according to an embodiment of the present disclosure. FIG. 2B is a cross-sectional view of line segment II-II’ of FIG. 2A. FIG. 3A is a three-dimensional schematic diagram of a second optical film according to an embodiment of the present disclosure. FIG. 3B is a cross-sectional view of line segment III-III’ of FIG. 3A. FIG. 4A is a three-dimensional schematic diagram of a third optical film according to an embodiment of the present disclosure. FIG. 4B is a cross-sectional view of line segment IV-IV’ of FIG. 4A. It should be noted that FIG. 2A, FIG. 3A or FIG. 4A only show the light-emitting element 20 and the first optical film 11, the second optical film 12 or the third optical film 13, and the light-emitting element 20 in FIG. 2A, FIG. 3A and FIG. 4A is only used to describe the arrangement direction of the light-emitting sub-unit 21.

First, the first optical film 11 is described. As shown in FIG. 2A , the extension direction of the first prism structure 111 of the first optical film 11 is the first direction D1, which is parallel or substantially parallel to the extension direction (Y) of the light-emitting sub-unit 21. More specifically, the "extension direction of the first prism structure 111" can be regarded as the extension direction of the first strip structure 111a. In one embodiment, the first optical film 11 can be allowed to have an offset error within positive or negative 5 degrees during assembly. For example, when the first optical film 11 is assembled on the substrate 10, there can be an angle between the first direction D1 and the extension direction (Y) of the light-emitting sub-unit 21, wherein the angle is less than or equal to positive or negative 5 degrees, and is not limited thereto.

As shown in FIG. 2B , in the cross-sectional view, each first strip-shaped structure 111a of the first prism structure 111 may include a plurality of edges e1 and e2, wherein two edges e1 and e2 may intersect at a vertex P1 to form the first strip-shaped structure 111a, and ends P2 and P3 of the two edges e1 and e2 may be connected to other first strip-shaped structures 111a, respectively, but not limited thereto. In addition, each first strip-shaped structure 111a of the first prism structure 111 may have a first prism angle θ1, and the “first prism angle θ1” may be, for example, the angle between the two edges e1 and e2. In one embodiment, the first strip structure 111a may be, for example, an isosceles triangle (but in other embodiments, it may be any other shape with an angle), in which case the two edges e1 and e2 have the same length, and the first prism angle θ1 may be regarded as the vertex angle of the isosceles triangle, but is not limited thereto. In one embodiment, the first prism angle θ1 may be between 30 degrees and 110 degrees (i.e., 30 ^° ≦θ1≦110 ^° ), but is not limited thereto. In one embodiment, the first prism angle θ1 may be between 40 degrees and 100 degrees (i.e., 40 ^° ≦θ1≦100 ^° ), but is not limited thereto. In one embodiment, the first prism angle θ1 may be between 50 degrees and 90 degrees (ie, 50 ^° ≦θ1≦90 ^° ), but is not limited thereto.

In addition, as shown in FIG. 2B , in the arrangement direction (e.g., X direction) of the plurality of first strip structures 111 a, there may be a first spacing d1 between the vertices P1 of two adjacent ones of the plurality of first strip structures 111 a. In one embodiment, the first spacing d1 may be between 10 microns and 30 microns (i.e., 10µm≦d1≦30µm), but is not limited thereto. In one embodiment, the first spacing d1 may be between 15 microns and 20 microns (i.e., 15µm≦d1≦20µm), but is not limited thereto. In one embodiment, the first spacing d1 may be between 17 microns and 19 microns (i.e., 17µm≦d1≦19µm), for example, 18 microns, but is not limited thereto.

Next, the second optical film 12 is described. As shown in FIG. 3A , in one embodiment, the extension direction of the light-emitting subunit 21 is substantially parallel to the first direction D1, the extension direction of the second prism structure 121 of the second optical film 12 is the second direction D2, and the second direction D2 may have an angle θ12 with the first direction D1 (shown in FIG. 1B ). In the embodiment of FIG. 3A , the angle θ12 is, for example, 90 degrees, but it may also be other angles (as shown in FIG. 5 ). More specifically, the “extension direction of the second prism structure 121” may be regarded as the extension direction of the second strip structure 121a. In one embodiment, the second optical film 12 may be allowed to have an offset error within positive or negative 10 degrees during assembly, and is not limited thereto.

As shown in FIG. 3B , in the cross-sectional view, each second strip-shaped structure 121a of the second prism structure 121 may include a plurality of edges e3 and e4, wherein two edges e3 and e4 may intersect at a vertex P4 to form the second strip-shaped structure 121a, and the ends P5 and P6 of the two edges e3 and e4 may be connected to other second strip-shaped structures 121a, respectively, but not limited thereto. In addition, each second strip-shaped structure 121a of the second prism structure 121 may have a second prism angle θ2, and the “second prism angle θ2” may be, for example, the angle between the two edges e3 and e4. In one embodiment, the second strip structure 121a may be, for example, an isosceles triangle (but in other embodiments, it may be any other shape with an angle), in which case the two edges e3 and e4 have the same length, and the second prism angle θ2 may be regarded as the vertex angle of the isosceles triangle, but is not limited thereto. In one embodiment, the second prism angle θ2 may be between 30 degrees and 140 degrees (i.e., 30 ^° ≦θ2≦140 ^° ), but is not limited thereto. In one embodiment, the second prism angle θ2 may be between 40 degrees and 130 degrees (i.e., 40 ^° ≦θ2≦130 ^° ), but is not limited thereto. In one embodiment, the second prism angle θ2 may be between 50 degrees and 120 degrees (ie, 50 ^° ≦θ2≦120 ^° ), but is not limited thereto.

In addition, as shown in FIG. 3B , in a horizontal direction (e.g., the Y direction), there may be a second spacing d2 between the vertices P4 of two adjacent ones of the plurality of second strip structures 121a. In one embodiment, the second spacing d2 may be between 40 microns and 60 microns (i.e., 40µm≦d2≦60µm), but is not limited thereto. In one embodiment, the second spacing d2 may be between 45 microns and 55 microns (i.e., 45µm≦d2≦55µm), but is not limited thereto. In one embodiment, the second spacing d2 may be between 47.5 microns and 52.5 microns (i.e., 47.5µm≦d2≦52.5µm), for example, 50 microns, but is not limited thereto.

Next, the third optical film 13 is described. As shown in FIG. 4A , in one embodiment, the extension direction of the light-emitting subunit 21 is substantially parallel to the first direction D1, and the extension direction of the third prism structure 131 of the third optical film 13 is the third direction D3, and there may be an angle (not shown) between the third direction D3 and the first direction D1, and the angle may be substantially the same as the angle θ12 (shown in FIG. 1B ) between the second direction D2 and the first direction D1, but is not limited thereto. In the embodiment of FIG. 3A , the angle is, for example, 90 degrees, but is not limited thereto. More specifically, the “extension direction of the third prism structure 131” may be regarded as the extension direction of the third strip structure 131a. In one embodiment, the third optical film 13 may be allowed to have an offset error within positive or negative 10 degrees during assembly, but is not limited thereto.

As shown in FIG. 4B , in the cross-sectional view, each third strip-shaped structure 131a of the third prism structure 131 may include a plurality of edges e5 and e6, wherein two edges e5 and e6 may intersect at a vertex P7 to form the third strip-shaped structure 131a, and the ends P8 and P9 of the two edges e5 and e6 may be connected to other third strip-shaped structures 131a, respectively, but not limited thereto. In addition, each third strip-shaped structure 131a of the third prism structure 131 may have a third prism angle θ3, and the “third prism angle θ3” may be, for example, the angle between the two edges e5 and e6. In one embodiment, the third strip structure 131a may be, for example, an isosceles triangle (but in other embodiments, it may be any other shape with an angle), in which case the two edges e5 and e6 have the same length, and the third prism angle θ3 may be regarded as the vertex angle of the isosceles triangle, but is not limited thereto. In one embodiment, the third prism angle θ3 may be between 30 degrees and 140 degrees (i.e., 30 ^° ≦θ3≦140 ^° ), but is not limited thereto. In one embodiment, the third prism angle θ3 may be between 40 degrees and 130 degrees (i.e., 40 ^° ≦θ3≦130 ^° ), but is not limited thereto. In one embodiment, the third prism angle θ3 may be between 50 degrees and 120 degrees (ie, 50 ^° ≦θ3≦120 ^° ), but is not limited thereto.

As shown in FIG. 4B , in the horizontal direction (e.g., the Y direction), there may be a third spacing d3 between the vertices P7 of two adjacent third strip structures 131a. In one embodiment, the third spacing d3 may be between 20 microns and 28 microns (i.e., 20µm≦d3≦28µm), but is not limited thereto. In one embodiment, the third spacing d3 may be between 22.5 microns and 26.5 microns (i.e., 22.5µm≦d3≦26.5µm), but is not limited thereto. In one embodiment, the third spacing d3 may be between 23 microns and 25 microns (i.e., 23µm≦d3≦25µm), for example, 24 microns, but is not limited thereto.

Please refer to FIG. 2B , FIG. 3B , and FIG. 4B again.

In one embodiment, the second prism angle θ2 or the third prism angle θ3 may be greater than the first prism angle θ1 (i.e., θ1<θ2, or θ1<θ3), and is not limited thereto. Advantages of this design include, for example, allowing light to be concentrated toward the normal viewing angle or improving the contrast of the display device 1, and are not limited thereto.

In one embodiment, the second distance d2 may be greater than the third distance d3, and the third distance d3 may be greater than the first distance d1 (ie, d1＜d3＜d2), but is not limited thereto. Advantages of this design include, for example, concentrating light toward a normal viewing angle or improving the contrast of the display device 1, but are not limited thereto.

In one embodiment, the refractive index n1 of the first optical film 11, the refractive index n2 of the second optical film 12, or the refractive index n3 of the third optical film 13 may be between 1.5 and 1.7 (i.e., 1.5≦n1≦1.7, or 1.5≦n2≦1.7, or 1.5≦n3≦1.7). In the present disclosure, the first optical film 11, the second optical film 12, and the third optical film 13 may be prepared using the same or different materials, and therefore, the refractive index n1, the refractive index n2, and the refractive index n3 may be the same or different. In one embodiment, the refractive index n3 of the third optical film 13 may be greater than the refractive index n2 of the second optical film 12 (i.e., n2<n3). The advantages of this design include, for example, allowing light to be concentrated toward the normal viewing angle or improving the contrast of the display device 1, but are not limited thereto.

In one embodiment, the positions of the vertex P4 of the second strip structure 121a of the second prism structure 121 and the vertex P7 of the third strip structure 131a of the third prism structure 131 in the horizontal direction (Y) may correspond to each other (for example, the vertex P4 and the vertex P7 may be aligned with each other) or may not correspond (for example, the vertex P4 and the vertex P7 may not need to be aligned), but is not limited thereto.

In one embodiment, the materials of the first optical film 11, the second optical film 12 and the third optical film 13 may include transparent materials, but are not limited thereto. In one embodiment, the first optical film 11, the second optical film 12 and the third optical film 13 may include base plates (e.g., first base plate 112, second base plate 122 and third base plate 132) and corresponding prism structures (e.g., first prism structure 111, second prism structure 121 and third prism structure 131). The material of the base plate or prism structure may include polycarbonate (PC), polyimide (PI), polyethylene terephthalate (PET), polyether polyol (POP), polymethylmethacrylate (PMMA), cycloolefin polymer (COP), rubber, glass, other suitable materials or combinations thereof, and are not limited thereto. In one embodiment, the material of the prism structure may include photocurable adhesive, thermal curable adhesive, photothermal curable adhesive, moisture curable adhesive, other suitable materials or combinations thereof, and are not limited thereto. In one embodiment, the material of the prism structure may include optical clear adhesive (OCA), optical clear resin (OCR), acrylic resin, other suitable materials or a combination thereof, but is not limited thereto.

Through the above design, in one embodiment, the side lobe of the backlight device 200 may be between 0.1% and 10% (i.e., 0.1%≦side lobe≦10%), and is not limited thereto. In one embodiment, the side lobe of the backlight device 200 may be between 0.1% and 5% (i.e., 0.1%≦side lobe≦5%), and is not limited thereto. In one embodiment, the side lobe of the backlight device 200 may be between 0.1% and 3% (i.e., 0.1%≦side lobe≦3%), and is not limited thereto. In one embodiment, the side lobe of the backlight device 200 may be between 0.1% and 1% (i.e., 0.1%≦side lobe≦1%), and is not limited thereto. Here, “side view light intensity” may refer to, for example, the light intensity perceived by the user in the viewing direction on a horizontal cross section (eg, a side cross section) of the display device 1 , but is not limited thereto.

In one embodiment, the side view light intensity of the backlight device 200 can be expressed as a formula: Side view light intensity = (Max)%-(45D)%% Wherein, Max is the maximum side view light intensity position, which is located in the range of about 45 degrees to 90 degrees from the user's viewing angle to the center of the horizontal section of the display device 1, 45D represents the position where the user's viewing angle deviates from the center of the horizontal section of the display device 1 by about 45 degrees, (Max)% is the light intensity at the maximum side view light intensity position, and (45D)% represents the light intensity at the position where the side view direction deviates from the center viewing angle by about 45 degrees, and is not limited thereto.

It can be seen from this that the present disclosure can significantly reduce the side light leakage problem of the backlight device 200. Therefore, the display device 1 of the present disclosure can meet the privacy requirements or reduce the side view light intensity without the need for additional attachment or installation of an anti-penetration film, or making the yield of the backlight module higher and/or lower in cost.

The display device 200 of the present disclosure may have different implementations. FIG5 is a three-dimensional diagram of a display device of another embodiment of the present disclosure, and please refer to FIG1A.

In FIG. 1A , the extension direction of the second prism structure 121 (i.e., the second direction D2) or the extension direction of the third prism structure 131 (i.e., the third direction D3) is perpendicular to the extension direction of the first prism structure 111 (i.e., the first direction D1). However, in FIG. 5 , the second direction D2 or the third direction D3 is not perpendicular to the first direction D1, and the second direction D2 and the third direction D3 may be substantially parallel. In other words, in FIG. 5 , the first direction D1 is parallel to the Y direction, and the second direction D2 and the third direction D3 are different from the X direction and the Y direction.

The display device 1 of the present disclosure may also have different implementations. FIG. 6 is a cross-sectional view of a display device of another embodiment of the present disclosure, and please refer to FIG. 1B .

Compared with the embodiment of FIG. 1B , the display device 1 of the embodiment of FIG. 6 further includes a viewing angle control panel 300. The viewing angle control panel 300 can be disposed on the display panel 100 in the normal direction (Z) of the substrate 10. In one embodiment, when a driving voltage is provided to the viewing angle control panel 300, the liquid crystal molecules in the viewing angle control panel 300 can rotate to achieve the effect of limiting the light output angle, so that the display device 1 forms an anti-peeping mode; and when the driving voltage is not provided to the viewing angle control panel 300, the liquid crystal molecules in the viewing angle control panel 300 do not move, so the display device 1 can form a sharing mode, but is not limited thereto.

Furthermore, in one embodiment, the display device 1 may further include a touch unit 400. In one embodiment, the touch unit 400 may be disposed on the viewing angle control panel 300 in the normal direction (Z) of the substrate 10. The touch unit 400 may be, for example, a touch panel, which may be implemented by TOD (touch on display) or projected capacitive touch panel (sensor glass) technology, but is not limited thereto. In another embodiment, the touch unit 400 may be disposed in the viewing angle control panel 300 or the display panel 100, which may be implemented by TID (touch in display) technology, but is not limited thereto.

In one embodiment, the present disclosure can at least compare a product by means of mechanical observation, such as using the presence or absence of a component or the operational relationship between components as evidence of whether the product falls within the scope of protection of the present disclosure, but is not limited thereto. In one embodiment, the mechanical observation can be achieved, for example, by using an optical microscope or a scanning microscope, but is not limited thereto.

The details or features of the various embodiments of the present disclosure may be mixed and matched as long as they do not violate the spirit of the invention or conflict with each other.

The display device 1 and the backlight device 200 disclosed in the present invention have been understood. Thus, the display device 1 disclosed in the present invention can provide a high contrast effect. Alternatively, the light emitted by the backlight device 200 can be concentrated toward the normal viewing angle, and the privacy requirement can be met without the need for additional attachment or installation of an anti-penetration film, or the yield of the backlight module can be higher or/and the cost can be lowered, or the side view light intensity can be reduced. Alternatively, the display device 1 disclosed in the present invention has high light package stability.

The above embodiments are merely examples for the purpose of convenience of explanation. The scope of rights claimed by the present disclosure shall be subject to the scope of the patent application, and shall not be limited to the above embodiments.

1: Display device 100: Display panel 200: Backlight device 10: Substrate 20: Light-emitting element 11: First optical film 12: Second optical film 13: Third optical film 21: Light-emitting subunit 111: First prism structure 121: Second prism structure 131: Third prism structure D1: First direction D2: Second direction D3: Third direction 111a: First strip structure 121a: Second strip structure 131a: Third strip structure θ12: Angle 112: First bottom plate 122: Second bottom plate 132: Third bottom plate 10a: Plane 30: Light-guiding element 40: Reflective element 50: Circuit board 60: plastic e1, e2, e3, e4, e5, e6: edge P1, P4, P7: apex P2, P3, P5, P6, P8, P9: end θ1: first prism angle θ2: second prism angle θ3: third prism angle d1: first distance d2: second distance d3: third distance 300: viewing angle control panel 400: touch unit

FIG. 1A is a cross-sectional schematic diagram of a display device according to an embodiment of the present disclosure. FIG. 1B is a three-dimensional diagram of a display device according to an embodiment of the present disclosure. FIG. 2A is a three-dimensional schematic diagram of a first optical film according to an embodiment of the present disclosure. FIG. 2B is a cross-sectional diagram of line segment II-II’ of FIG. 2A. FIG. 3A is a three-dimensional schematic diagram of a second optical film according to an embodiment of the present disclosure. FIG. 3B is a cross-sectional diagram of line segment III-III’ of FIG. 3A. FIG. 4A is a three-dimensional schematic diagram of a third optical film according to an embodiment of the present disclosure. FIG. 4B is a cross-sectional diagram of line segment IV-IV’ of FIG. 4A. FIG. 5 is a three-dimensional diagram of a display device according to another embodiment of the present disclosure. FIG. 6 is a cross-sectional diagram of a display device according to another embodiment of the present disclosure.

1: Display device

100: Display panel

200: Backlight device

10: Base

10a: Plane

20: Light-emitting element

11: First optical film

12: Second optical film

13: The third optical film

21: Photon-emitting unit

111: First prism structure

121: Second prism structure

131: The third prism structure

111a: The first strip structure

121a: The second strip structure

131a: The third strip structure

112: First base plate

122: Second base plate

132: The third base plate

30: Light-guiding element

40: Reflective element

50: Circuit board

60: Rubber material

Claims (10)

A backlight device comprises: a substrate; a light-emitting element disposed on the substrate for providing a light source; a first optical film disposed on the substrate and comprising a first prism structure extending along a first direction; a second optical film disposed on the first optical film and comprising a second prism structure extending along a second direction; and a third optical film disposed on the second optical film and comprising a third prism structure extending along a third direction; wherein the angle between the first direction and the second direction is between 30 degrees and 150 degrees, and the second direction is parallel to the third direction. A backlight device as described in claim 1, wherein in a normal direction of the substrate, the first prism structure and the second prism structure face the same direction, the third prism structure and the second prism structure face opposite directions, and the first prism structure faces the substrate. The backlight device as described in claim 1 further includes a light-guiding element arranged adjacent to the light-emitting element. A backlight device as described in claim 1, wherein the first prism structure has a first prism angle, the second prism structure has a second prism angle, and the third prism structure has a third prism angle, wherein the first prism angle is between 50 degrees and 90 degrees, and the second prism angle or the third prism angle is between 50 degrees and 120 degrees. A backlight device as described in claim 1, wherein the first optical film, the second optical film and the third optical film are in contact with each other. The backlight device as described in claim 1, wherein the refractive index of the first optical film, the second optical film or the third optical film is between 1.5 and 1.7. A backlight device as described in claim 1, wherein the first prism structure has a plurality of first strip structures, and there is a first distance between two adjacent ones of the plurality of first strip structures; the second prism structure has a plurality of second strip structures, and there is a second distance between two adjacent ones of the plurality of second strip structures; the third prism structure has a plurality of third strip structures, and there is a third distance between two adjacent ones of the plurality of third strip structures, wherein the second distance is greater than the third distance, and the third distance is greater than the first distance. A display device, comprising: A backlight device, comprising; A substrate; A light-emitting element, disposed on the substrate, for providing a light source; A first optical film, disposed on the substrate, comprising a first prism structure extending along a first direction; A second optical film, disposed on the first optical film, comprising a second prism structure extending along a second direction; and A third optical film, disposed on the second optical film, comprising a third prism structure extending along a third direction, wherein the angle between the first direction and the second direction is between 30 degrees and 150 degrees, and the second direction is parallel to the third direction; and A display panel, disposed on the backlight device. The display device as described in claim 8 further includes a viewing angle control panel disposed on the display panel. The display device as described in claim 9 also includes a touch unit disposed on the viewing angle control panel.