CN114488383A

CN114488383A - Light source, base material for forming light guide film, light guide film and forming method thereof

Info

Publication number: CN114488383A
Application number: CN202011262111.1A
Authority: CN
Inventors: 徐耀东; 刘金涌; 邓嘉峰; 林进伟
Original assignee: Hannstar Display Nanjing Corp; Hannstar Display Corp
Current assignee: Hannstar Display Nanjing Corp; Hannstar Display Corp
Priority date: 2020-11-12
Filing date: 2020-11-12
Publication date: 2022-05-13
Anticipated expiration: 2040-11-12
Also published as: CN114488383B

Abstract

The invention discloses a base material for forming a light guide film, the light guide film, a light source and a method for forming the light guide film, wherein the base material for forming the light guide film comprises a main body part and a folding part. The main body part comprises a light emitting area. The folding part is positioned at one side of the main body part and comprises a plurality of folding surfaces, wherein at least one cutting line and at least one folding line are arranged between every two adjacent folding surfaces.

Description

Light source, base material for forming light guide film, light guide film and forming method thereof

Technical Field

The present invention relates to a light guide film, and more particularly, to a light guide film having a folding structure with cutting lines, a light source used in the light guide film, a substrate used in the light guide film, and a method of forming the light guide film.

Background

In recent years, light guide films (light guide films) are widely used in various electronic devices, such as smart phones, tablet computers, notebook computers, electronic book readers, wearable devices, etc. in cooperation with light emitting devices, i.e. light guide technology and display technology can be integrated into the electronic devices.

In the prior art, in order to save space and integrate the arrangement of the light emitting device, the structure of the light guiding film needs to be specially designed, the processing procedure and assembly thereof are complicated and difficult, the required cost is high, and the quality is not easy to control. Moreover, the number of the corresponding light-emitting elements is limited, the overall light-guiding path is long, and the light conduction and light extraction benefits are poor.

Disclosure of Invention

An objective of the present invention is to provide a light guiding film, a light guiding film and a light source using the same, a substrate for forming the light guiding film, and a method for forming the light guiding film, so as to solve the problems encountered by the conventional light guiding film.

To achieve the above object, the present invention provides a substrate for forming a light guiding film, comprising a main body portion and a folded portion. The main body part comprises a light emitting area. The folding part is positioned at one side of the main body part and comprises a plurality of folding surfaces, wherein at least one cutting line and at least one folding line are arranged between every two adjacent folding surfaces.

To achieve the above objective, the present invention provides a light guiding film, comprising the substrate for forming the light guiding film, wherein a plurality of folding surfaces are stacked to form a stacking portion. The stacking part comprises a connecting part and an incident part, wherein the connecting part is positioned on one side of the incident part, and the incident part comprises an incident surface.

To achieve the above object, the present invention provides a light source, which includes the light guiding film and at least one light emitting element, wherein light emitted from the light emitting element is transmitted to a light incident portion.

To achieve the above object, the present invention provides a method of forming a light guiding film, comprising: providing the substrate as described above, and folding any two adjacent folding surfaces of the plurality of folding surfaces along the folding line therebetween, so that the plurality of folding surfaces are stacked to form a stacked portion.

According to the light guide film, the light source applicable to the light guide film, the base material for forming the light guide film and the method for forming the light guide film, the light guide film can be formed by simple reverse folding and stacking procedures through a special folding structure design, the whole light guide path is short, and the light conduction and light emitting benefits are good. In addition, different designs can be carried out on the setting position and the setting angle of the light inlet part according to the requirements of the light outlet brightness, the number of the correspondingly arranged light emitting elements, the image quality and the like, so that the space utilization rate is improved, and meanwhile, the light emitting elements can be arranged in a dispersing way, so that the high temperature problem caused by intensive arrangement is avoided.

Drawings

Fig. 1 is a schematic top view of a base material for forming a light guiding film and a folded light guiding film according to a first embodiment of the present invention, wherein a right portion of fig. 1 illustrates a schematic top view of a light guiding film and a light emitting device in a light source application.

FIG. 2A is a schematic cross-sectional view of the light guiding film shown in FIG. 1 taken along line A-A'.

FIG. 2B is a schematic cross-sectional view of the light guiding film shown in FIG. 1 taken along line B-B'.

Fig. 3 is a schematic diagram illustrating a path of light emitted from the light emitting element when no cutting line is provided at each of the folds between the plurality of folded surfaces in the light incident portion of the light guiding film.

Fig. 4 is a schematic diagram illustrating a light transmission path of a light emitting element when a cutting line is formed at each of folds between a plurality of folding surfaces in a light incident portion of a light guiding film according to the present invention.

Fig. 5 is a schematic top view of a base material for forming a light guiding film and a folded light guiding film according to a second embodiment of the present invention, wherein a right portion of fig. 5 illustrates a schematic top view of a light guiding film and a light emitting device in a light source application.

FIG. 6A is a schematic cross-sectional view of the light guiding film shown in FIG. 5 taken along line A-A'.

FIG. 6B is a schematic cross-sectional view of the light guiding film shown in FIG. 5 taken along line B-B'.

FIG. 7 is a substrate for forming a light guiding film according to a third embodiment of the present invention.

Fig. 8 is a schematic top view of a light guiding film formed by folding a base material according to a third embodiment of the present invention and a schematic top view of a light source used in combination with a light emitting device.

FIG. 9 is a substrate for forming a light guiding film according to a fourth embodiment of the present invention.

Fig. 10 is a schematic top view of a light guiding film formed by folding a base material according to a fourth embodiment of the invention and a schematic top view of a light source used in combination with a light emitting device.

Description of reference numerals: 100. 100 ', 400' -substrate; 110. 410-a body portion; 120. 420-a fold; 1201-a first fold; 1202-second fold; 122. 122_1, 122_2, 122_3, 122_4, 122a, 422_1, 422_2, 422_ 3-fold planes; 1221-a first fold plane; 1222-a second folded surface; 200. 200 ', 200a, 500' -light directing film; 210. 510-a stack; 212. 512-a connecting part; 214. 214a, 514-light incident part; 214S, 214aS, 514S-light incident surface; 300. 300 ', 600' -light source; 1221. 4221-first side; 1222. 4222-second side edge; CL, CL _1, CL _ 2-cut lines; CL1 — first cut line; CL2 — second cut line; d1-first direction; d2-second direction; FL, FL _1, FL _2, FL _ 3-fold lines; FL 1-first fold line; FL 2-second fold line; an FR-fold region; FR1 — first fold area; FR2 — second fold region; h1 — first height; h2 — second height; l-ray; l1, L2, L3, L4-length; LE-light emitting element; OR-light emitting area; s1 — first side; s2 — second side; θ 1-a first included angle; theta 2-second angle; theta A-angle.

Detailed Description

The present disclosure will be described in detail with reference to the following detailed description and accompanying drawings, wherein the various figures of the disclosure depict only some of the devices and are not necessarily to scale, so as to make the reader readily aware of the description and the figures are simplified. In addition, the number and size of the elements in the figures are merely illustrative and are not intended to limit the scope of the present disclosure.

Certain terms are used throughout the description and following claims to refer to particular components. Those skilled in the art will appreciate that electronic device manufacturers may refer to the same components by different names. This document does not intend to distinguish between components that differ in function but not name. In the following description and claims, the terms "including" and "comprising" are used in an open-ended fashion, and thus should be interpreted to mean "including, but not limited to …". When the terms "comprising," "including," and/or "having" are used in this specification, they specify the presence of stated features, regions, steps, operations, and/or elements, but do not preclude the presence or addition of one or more other features, regions, steps, operations, elements, and/or groups thereof.

It will be understood that when an element is referred to as being "on" or "connected to" another element, it can be directly on or connected to the other element or intervening elements may be present. In contrast, when an element is referred to as being "directly on" or "directly connected to" another element, there are no intervening elements present between the two.

It is to be understood that the features of the various embodiments may be interchanged, recombined, mixed and modified in order to implement other embodiments without departing from the spirit of the present disclosure.

Please refer to fig. 1, fig. 2A and fig. 2B. Fig. 1 is a schematic top view of a base material for forming a light guiding film and a folded light guiding film according to a first embodiment of the present invention, wherein a right portion of fig. 1 further illustrates a schematic top view of the light guiding film and a light emitting device of the first embodiment of the present invention applied together as a light source. FIG. 2A is a schematic cross-sectional view of the light guiding film shown in FIG. 1 taken along line A-A'. FIG. 2B is a schematic cross-sectional view of the light guiding film shown in FIG. 1 taken along line B-B'. As shown in fig. 1, fig. 2A and fig. 2B, in some embodiments, the substrate 100 for forming the light guiding film includes a main portion 110 and a folded portion 120, wherein the substrate 100 includes a flexible material, for example, but not limited to, a plastic material such as polyethylene terephthalate (PET) or Polycarbonate (PC). The body 110 includes a light exit region OR, the folded portion 120 is located on one side of the body 110 and includes a plurality of folded surfaces 122, wherein at least one cutting line CL and at least one folding line FL are located between two adjacent folded surfaces 122. The cutting line CL refers to a slit formed between two adjacent folding surfaces 122 by cutting, the folding line FL is located between the two adjacent folding surfaces 122, and refers to a predetermined folding line that is intended to fold the substrate 100 along the line to separate the two adjacent folding surfaces 122 when forming the light guide film, and after folding along the folding line FL, the two adjacent folding surfaces 122 are stacked on each other in a direction perpendicular to the folding portion 120 such that the two adjacent folding surfaces 122 are located at different heights in different horizontal planes or directions perpendicular to the folding portion 120, respectively. The extending direction of the cutting line CL may be parallel to the extending direction of the folding line FL, but is not limited thereto. In the present embodiment, two cutting lines CL and one folding line FL are disposed between two adjacent folding surfaces 122, wherein the two cutting lines CL are disposed on two sides, and the folding line FL is disposed between the two cutting lines CL and connected to the cutting lines CL on two sides, but not limited thereto. The number of the cutting lines CL and the folding lines FL between the two folding surfaces 122 can be arranged according to the actual design requirement.

The light guide film 200 may be formed by stacking the folded surfaces 122 by folding the plurality of folded surfaces 122 of the substrate 100 along the folding line FL. The formed light guiding film 200 includes a main body portion 110 and at least one stacking portion 210. The main body 110 includes a light-emitting area OR, and the at least one stacking portion 210 is disposed in at least one folding area FR, wherein the folding area FR is located on at least one side of the light-emitting area OR. Each stacking portion 210 includes a plurality of stacked folding surfaces 122, that is, the stacking portion 210 is formed by folding and stacking the plurality of folding surfaces 122 of the substrate 100 along the folding line FL, for example, the folding surface 122_2 can be folded onto the folding surface 122_1 along the folding line FL _1, so that the folding surface 122_1 and the folding surface 122_2 are stacked on each other; next, the folding surface 122_3 is folded onto the folding surface 122_2 along the folding line FL _2, so that the folding surfaces 122_1, 122_2 and 122_3 are stacked in sequence; the folding surface 122_4 is then folded onto the folding surface 122_3 along the folding line FL _3, so that the folding surfaces 122_1, 122_2, 122_3, and 122_4 are sequentially stacked to form the stacking portion 210, but not limited thereto. In some embodiments, the folding surface 122_4 may also be folded onto the folding surface 122_3 along the folding line FL _3, so that the folding surface 122_3 and the folding surface 122_4 are stacked on each other; next, the stacked folding surfaces 122_3 and 122_4 are folded below the folding surface 122_2 along the folding line FL _2, so that the folding surfaces 122_2, 122_3 and 122_4 are stacked in sequence; the stacked folding surfaces 122_2, 122_3, and 122_4 are then folded onto the folding surface 122_1 along the folding line FL _1, so that the folding surfaces 122_1, 122_2, 122_3, and 122_4 are sequentially stacked to form the stacked portion 210, but is not limited thereto. In other embodiments, the folding surface 122_4 may also be folded onto the folding surface 122_3 along the folding line FL _3, so that the folding surfaces 122_3 and 122_4 are stacked on each other; next, the folding surface 122_2 is folded onto the folding surface 122_1 along the folding line FL _1, so that the folding surfaces 122_1 and 122_2 are stacked on each other; the stacked folding surfaces 122_3 and 122_4 are then folded along the folding line FL _2 to the upper side of the stacked folding surfaces 122_1 and 122_2, so that the folding surfaces 122_1, 122_2, 122_3 and 122_4 are sequentially stacked to form the stacked portion 210, but is not limited thereto. The present invention does not limit the folding order of the folding planes 122. In addition, in other embodiments, the folding surface 122_4 may also be folded onto the folding surface 122_3 along the folding line FL _3, so that the folding surfaces 122_3 and 122_4 are stacked on each other; next, the stacked folding surfaces 122_3 and 122_4 are folded onto the folding surface 122_2 along the folding line FL _2, so that the folding surfaces 122_2, 122_4 and 122_3 are stacked in sequence; the stacked folding surfaces 122_2, 122_4, and 122_3 are then folded along the folding line FL _1 to be above or below the folding surface 122_1, so that the folding surfaces 122_1, 122_3, 122_4, and 122_2 are sequentially stacked or the folding surfaces 122_3, 122_4, 122_2, and 122_1 are sequentially stacked to form the stacked portion 210, but not limited thereto. The present invention does not limit the stacking order of the folding surfaces 122 in the stacking portion 210. According to the embodiment of the invention, the method for forming the light guide film comprises the following steps: firstly, a substrate is provided, which comprises a main body part and a folding part, wherein the folding part of the substrate comprises N folding surfaces, the N folding surfaces comprise 1 st to N th folding surfaces which are sequentially arranged along a direction, the 1 st folding surface is coupled with the main body part, or the 1 st folding surface is the folding surface which is closest to the main body part in the 1 st to N th folding surfaces, the ith folding surface is adjacent to the (i +1) th folding surface, N is a positive integer which is greater than or equal to 2, and i is a positive integer which is greater than or equal to 1 and less than or equal to (N-1). Next, any two adjacent folding surfaces of the N folding surfaces are folded along a folding line therebetween, so that the 1 st to nth folding surfaces are stacked on each other to form a stacked portion. The 1 st to nth folded surfaces in the stacked portion are preferably stacked in order in a top view direction. The stacking portion 210 includes a connecting portion 212 and at least one light incident portion 214, wherein the connecting portion 212 is located at one side of the light incident portion 214. Each light incident portion 214 includes a light incident surface 214S for being disposed opposite to at least one light emitting element LE (as shown in fig. 2A), and light emitted from the light emitting element LE can enter the light guiding film 200 through the light incident surface 214S, wherein the light emitting element LE can be, for example but not limited to, a Light Emitting Diode (LED), so that the light guiding film 200 and one or more light emitting elements LE disposed opposite to the light incident portion 214 of the light guiding film 200 can be used as the light source 300, for example, can be applied in a display device, as a front light source or a rear light source of a display panel, but not limited thereto. For example, the light source 300 may be disposed above, for example but not limited to, a reflective display panel as a front light; alternatively, the light source 300 may be disposed below the display panel to serve as a backlight (back light). The light emitted from the light emitting element LE enters the light guiding film 200 through the light incident surface 214S, and then is transmitted to the display panel through the light emitting area OR. In some embodiments, the light incident portion 214 has a first height H1 in a direction perpendicular to the main body portion 110, the light emitting element LE has a second height H2 in the direction perpendicular to the main body portion 110, and the first height H1 is greater than the second height H2, so as to increase the efficiency of light entering the light guiding film 200, that is, the number of the stacking surfaces 122 in the stacking portion 210 can be adjusted according to the second height H2 of the light emitting element LE, so that the light incident portion 214 of the stacking portion 210 has a first height H1 greater than the second height H2 of the light emitting element LE, but is not limited thereto. In some embodiments, the first height H1 of the light incident portion 214 may be less than or equal to the second height H2 of the light emitting element LE.

In the light incident portion 214, each of the folded portions between the plurality of folded surfaces 122 has a cutting line 122 extending along the first direction D1, so that the adjacent folded surfaces 122 are cut apart at the portion of the light incident portion 214 and are not connected to each other, when the folded surfaces 122 are folded, the portions of the folded surfaces 122 at the light incident portion 214 can be closely attached to each other to form a close stacked structure, and the light incident surface 214S can be a flat surface (as shown in fig. 2A), which can effectively reduce light reflection and light loss, so that the light emitted by the light emitting element LE can better enter the light guiding film 200, thereby further increasing the light transmission efficiency. In contrast, in the connection portion 212, the folding portions of the folding surfaces 122 are connected to each other without cutting lines, and the folding surfaces 122 are folded along the folding line FL and stacked on each other (as shown in fig. 2B), so that the light guide film 200 is prevented from being folded or broken due to dead fold, and further the transmission of light is prevented from being affected. Through the above folding structure design, the light guiding film 200 can be formed by simple folding and stacking processes, and the whole light guiding path is shorter, and the light conduction and light emitting benefits are better.

The advantage of the arrangement of the cutting lines 122 to increase the efficiency of light conduction is further explained next. Please refer to fig. 3 and fig. 4. Fig. 3 is a schematic diagram illustrating a path of light transmitted by the light emitting element LE when no cutting line is formed at each of the folds between the plurality of folded surfaces in the light incident portion of the light guide film, and fig. 4 is a schematic diagram illustrating a path of light transmitted by the light emitting element LE when a cutting line is formed at each of the folds between the plurality of folded surfaces in the light incident portion of the light guide film according to the present invention. aS shown in fig. 3, the light guiding film 200a without the cutting lines has a curved surface at the bending portion of the adjacent folding surface 122a, that is, the light incident surface 214aS has a curved surface, so that light refraction is easily caused, and the light L entering the light guiding film 200a is lost. In addition, the light L entering the light guiding film 200a encounters a crease (dotted circle) and is reproduced as stray light L and lost. As shown in fig. 4, the folded surfaces 122 of the light incident portion 214 of the light guiding film 200 with the cutting lines are closely adhered to each other to form a close stacked structure, and the light incident surface 214S is planar, so that the light L is not reflected or lost, thereby increasing the light transmission efficiency.

In the present embodiment, the light guiding film 200 may include, for example, a stack portion 210 disposed in a folding region FR, wherein the folding region FR is located at one side of the light emitting region OR, and the stack portion 210 includes a connecting portion 212 and two light incident portions 214, the two light incident portions 214 are respectively located at two opposite ends of the stack portion 210, and the connecting portion 212 connects the two light incident portions 214. However, the number of the stacking units 210 and the number of the light incident units 214 included in the stacking units 210 are not limited thereto, and the arrangement positions of the stacking units 210 and the arrangement positions of the light incident units 214 are not limited thereto. That is, according to the actual design requirement, the light guiding film 200 may include one or more stacking portions 210, the stacking portion 210 may include one or more light incident portions 214, and the stacking portions 210 and the light incident portions 214 may be disposed at any side of the light guiding film 200, such as (but not limited to) one, two, three or four sides of the light guiding film 200, and one or more light emitting elements LE are disposed oppositely to adjust the brightness and uniformity of the emitted light.

Please refer to fig. 5, fig. 6A, and fig. 6B. Fig. 5 is a schematic top view of a base material for forming a light guiding film and a folded light guiding film according to a second embodiment of the present invention, wherein a right portion of fig. 5 illustrates a schematic top view of a light guiding film and a light emitting device used in combination as a light source according to the second embodiment of the present invention. FIG. 6A is a schematic cross-sectional view of the light guiding film shown in FIG. 5 taken along line A-A'. FIG. 6B is a schematic cross-sectional view of the light guiding film shown in FIG. 5 taken along line B-B'. As shown in fig. 5, 6A and 6B, in some embodiments, the substrate 100' for forming a light guiding film includes a main body portion 110, a first folding portion 1201 and a second folding portion 1202, the main body portion 110 includes a light emitting region OR, the first folding portion 1201 is located on one side of the main body portion 110, and the second folding portion 1202 is located on the other side of the main body portion 110, in this embodiment, the first folding portion 1201 and the second folding portion 1202 are located on opposite sides of the main body portion 110, but not limited thereto. The first folding portion 1201 includes a plurality of first folding faces 1221, wherein at least one first cutting line CL1 and at least one first folding line FL1 are disposed between two adjacent first folding faces 1221. In the present embodiment, two first cutting lines CL1 and one first folding line FL1 are provided between two adjacent first folding surfaces 1221, wherein the two first cutting lines CL1 are located at two sides, and the first folding line FL1 is located between the two first cutting lines CL1 and connected to the two first cutting lines CL1, but not limited thereto. The second folded portion 1202 includes a plurality of second folded surfaces 1222, wherein at least one second cutting line CL2 and at least one second folding line FL2 are disposed between two adjacent second folded surfaces 1222. In the present embodiment, an example that one second cutting line CL2 and two second folding lines FL2 are disposed between two adjacent second folding surfaces 1222 is taken as an example, wherein the two second folding lines FL2 are located at two sides, and the second cutting line CL2 is located between the two second folding lines FL2 and is connected to the two second folding lines FL2, but not limited thereto. The number of the first cutting lines CL1 and the first folding lines FL1 of the two first folding surfaces 1221 and the number of the second cutting lines CL2 and the second folding lines FL2 of the two second folding surfaces 1222 may be arranged according to actual design requirements.

The light guide film 200 'may be formed by folding the base material 100' along the first folding line FL1 to stack the first folding surface 1221 and folding along the second folding line FL2 to stack the second folding surface 1222. The formed light guiding film 200' includes a main body portion 110, a first stacked portion 2101, and a second stacked portion 2102. The body portion 110 includes a light emitting region OR, and the light emitting region OR includes a first side S1 and a second side S2 opposite to the first side S1. The first stacking portion 2101 is disposed in the first folding region FR1, and the second stacking portion 2102 is disposed in the second folding region FR2, wherein the first folding region FR1 is located on the first side S1 of the light emitting region OR, the first folding region FR1 is adjacent to the first side S1 of the light emitting region OR, and the second folding region FR2 is located on the second side S2 of the light emitting region OR, the second folding region FR2 is adjacent to the second side S2 of the light emitting region OR. The first stacked portion 2101 includes a plurality of first folded surfaces 1221 stacked, and the second stacked portion 2102 includes a plurality of second folded surfaces 1222 stacked, that is, the first stacked portion 2101 is formed by folding and stacking the first folded surface 1221 of the base material 100 'along the folding line FL1, and the second stacked portion 2102 is formed by folding and stacking the second folded surface 1222 of the base material 100' along the folding line FL 2.

In some embodiments, the first folding region FR1, the light exiting region OR and the second folding region FR2 are sequentially arranged along the second direction D2, and the second direction D2 is different from the first direction D1, and the second direction D2 may be, for example, perpendicular to the first direction D1, but is not limited thereto. Here, the first stacking unit 2101 includes two light incident portions 214, the second stacking unit 2102 includes one light incident portion 214, and the two light incident portions 214 of the first stacking unit 2101 and the one light incident portion 214 of the second stacking unit 2102 do not overlap in the second direction D2. In this embodiment, the two light incident portions 214 included in the first stacking portion 2101 are respectively located at two opposite sides of the first stacking portion 2101, a middle area of the first stacking portion 2101 is the connection portion 212, one light incident portion 214 included in the second stacking portion 2102 is located at a middle area of the second stacking portion 2102, and two sides of the second stacking portion 2102 are the connection portions 212. The light incident surface 214S of the light incident portion 214 located at both sides of the first stacked portion 2101 can be made to be a flat surface by the design of the first cutting line CL1 (as shown in fig. 6A), and the light incident surface 214S of the light incident portion 214 located at the middle region of the second stacked portion 2102 can be made to be a flat surface by the design of the second cutting line CL2 (as shown in fig. 6B), so that the light transmission efficiency can be increased. Referring to fig. 1 and 5, in the first embodiment of fig. 1, the two light incident portions 214 of the light guiding film 200 respectively overlap with the left area and the right area of the main body 110 in the second direction D2, and do not overlap with the middle area of the main body 110 in the second direction D2; in the embodiment of fig. 5, the left area and the right area of the main body 110 respectively overlap with the two light incident portions 214 of the first stacking portion 2101 of the light guiding film 200 ' in the second direction D2, and the middle area of the main body 110 overlaps with the light incident portion 214 of the second stacking portion 2102 of the light guiding film 200 ' in the second direction D2, so that compared with the first embodiment of fig. 1, the second embodiment can arrange a plurality of light incident portions 214 (as shown in the right portion of fig. 5) respectively corresponding to the left area, the right area and the middle area of the main body 110 by the arrangement positions of the light incident portions 214 respectively included in the first stacking portion 2101 and the second stacking portion 2102, thereby forming a light source 300 ' with higher luminance and uniformity.

Please refer to fig. 7 and fig. 8. FIG. 7 is a substrate for forming a light guiding film according to a third embodiment of the present invention. Fig. 8 is a schematic top view of a light guiding film formed by folding a base material according to a third embodiment of the present invention and a schematic top view of a light source used in combination with a light emitting device. As shown in fig. 7 and 8, in some embodiments, the base material 400 for forming the light guiding film includes a main body portion 410 and a folding portion 420, the main body portion 410 includes a light emitting region OR, the folding portion 420 is located on one side of the main body portion 410 and includes a plurality of folding surfaces 422, wherein at least one cutting line CL and at least one folding line FL are located between two adjacent folding surfaces 422. Each folding surface 422 has a first side edge 4221, the first side edge 4221 of one folding surface 422 of two adjacent folding surfaces 422 and the first side edge 4221 of the other folding surface 422 are coupled to the cutting line CL between the two adjacent folding surfaces 422, and a first included angle θ 1 is formed between the extending direction of the first side edge 4221 of each folding surface 422 and the extending direction of the folding line FL, where the first included angle θ 1 is greater than 0 degree and less than 90 degrees, so the first side edge 4221 can also be referred to as a first oblique edge 4221. In some embodiments, the folding surfaces 422 further have second side edges 4222, the second side edge 4222 of one folding surface 422 and the second side edge 4222 of the other folding surface 422 of two adjacent folding surfaces 422 are coupled to the cutting line CL between the two adjacent folding surfaces 422, and the extending direction of the second side edge 4222 of each folding surface 422 and the extending direction of the folding line FL respectively have a second included angle θ 2, and the second included angle θ 2 is greater than 0 degree and less than 90 degrees, so that the second side edge 4222 can also be referred to as a second oblique edge 4221. As shown in fig. 7 and 8, the two first side edges 4221 of the two adjacent folding surfaces 422 and the two second side edges 4222 of the two adjacent folding surfaces 422 are in a "<" shape or a ">" shape in a top view. According to various embodiments of the present invention, each folding surface 422 may have a beveled edge on only one side and no beveled edge on the other side, or each folding surface 422 may have a first beveled edge on one side and a second beveled edge on the other side. In this embodiment, each folding surface 422 has a first oblique edge and a second oblique edge, and the first included angle θ 1 is the same as the second included angle θ 2, but not limited thereto.

The light guiding film 500 may be formed by stacking the folding surfaces 422 by folding the base material 400 along the folding lines FL. The light guiding film 500 includes a main body portion 410 and at least one stacking portion 510. The stacking portion 510 includes a plurality of folded surfaces 422 stacked, that is, the stacking portion 510 is formed by folding and stacking the folded surfaces 422 of the base material 400 along the folding line FL. The stacking portion 510 includes a connection portion 512 and at least one light incident portion 514, the connection portion 512 is located at one side of the light incident portion 514, wherein, when viewed from a top view direction, an included angle θ a is formed between the light incident surface 514S of at least one of the light incident portions 514 and the first direction D1, the included angle θ a is the same as the first included angle θ 1 or the second included angle θ 2, that is, the included angle θ a is greater than 0 degree and smaller than 90 degrees. In the present embodiment, the stacking portion 510 includes two light incident portions 514, and an included angle θ a is formed between the light incident surface 514S of each light incident portion 514 and the first direction D1, but the disclosure is not limited thereto. The light incident surface 514S of each light incident portion 514 is arranged to face at least one light emitting element LE (as shown in fig. 8), so that the light guiding film 500 and the light emitting element LE arranged to face the light incident portion 514 of the light guiding film 500 can be used as the light source 600. Referring to fig. 1, fig. 7 and fig. 8, in the first embodiment of fig. 1, each folding surface 122 has a first side edge 1221 and a second side edge 1222 opposite to each other, the first side edge 1221 of one folding surface 122 and the first side edge 1221 of the other folding surface 122 of two adjacent folding surfaces 122 are coupled to the cutting line CL between the two adjacent folding surfaces 122, the second side edge 1222 of one folding surface 122 and the second side edge 1222 of the other folding surface 122 are coupled to the cutting line CL between the two adjacent folding surfaces 122, the first side edge 1221 of each folding surface 122 extends at an angle of 90 degrees to the extending direction of the folding line FL, and the second side edge 1222 of each folding surface 122 extends at an angle of 90 degrees to the extending direction of the folding line FL, that is, the folding surface 122 of the first embodiment of fig. 1 does not have a bevel edge of the folding surface 422 of the third embodiment of fig. 3, in addition, since the included angle between the light incident surface 214S of the light incident portion 214 of the first embodiment of fig. 1 and the first direction D1 is 0 degree, the length L1 of the light incident surface 214S of the light incident portion 214 is equal to the length of the light incident portion 214 in the first direction D1 when viewed from the top. However, as shown in fig. 7 and 8, since the incident surface 514S of each light incident portion 514 of the third embodiment has an included angle θ a different from 0 degree with the first direction D1, when viewed from the top, the length L2 of the incident surface 514S of the light incident portion 514 is greater than the length (equal to L2 multiplied by cos θ a) of the incident surface 514S of the light incident portion 514 projected on the first direction D1. As can be seen from the above, in the first embodiment and the third embodiment, if the lengths of the substrates in the first direction D1 are the same, and the lengths of the folding lines FL between two adjacent folding surfaces are the same, the length of the light incident surface of the light incident portion of the third embodiment can be longer than that of the first embodiment, so that more light emitting elements LE can be disposed. In the third embodiment, by designing the included angle θ a, the length of the light incident surface 514S of the light incident portion 514 can be longer in a limited space, so that a plurality of light emitting elements LE can be arranged, and the size of the included angle θ a can be designed in different angles according to the requirements of the light emitting brightness, the number of the light emitting elements LE correspondingly arranged, the image quality and the like.

As shown in fig. 7 and 8, since the folding surfaces 422 have the first oblique edge 4221 and the second oblique edge 4222, after the folding surfaces 422 are stacked to form the stacked portion 510, two adjacent folding surfaces 422 are separated at the light incident portion 514 and are not connected to each other, and are closely attached to each other and stacked to form a close stacked structure, and the light incident surface 514S is a flat surface, so that light reflection and light loss can be effectively reduced, and light emitted by the light emitting element LE can better enter the light guiding film 500, so as to further increase the light conduction efficiency. Further, in the present third embodiment, a cutting line CL is provided between two adjacent folding surfaces 422. As shown in fig. 7, a cutting line CL _1 is disposed between the adjacent folding surfaces 422_1 and 422_2, and a cutting line CL _2 is disposed between the adjacent folding surfaces 422_2 and 422_3, so that the edges of the light incident portion 514 and the light incident portion 514 can be prevented from having creases as shown in fig. 3, and light scattering and loss can be avoided, but not limited thereto. In some embodiments, the cutting line CL may be disposed between some adjacent folding surfaces 422, and may not be disposed between other adjacent folding surfaces 422. For example, a cutting line CL _2 may be disposed between the adjacent folding surfaces 422_2 and 422_3 to prevent the light incident portion 514 from having a crease, and no cutting line CL may be disposed between the adjacent folding surfaces 422_1 and 422_ 2. In summary, a substrate includes a main body portion and a folding portion, wherein the folding portion of the substrate includes N folding surfaces, the N folding surfaces include the 1 st to nth folding surfaces sequentially arranged along a direction, the 1 st folding surface is coupled to the main body portion, or the 1 st folding surface is the folding surface closest to the main body portion among the 1 st to nth folding surfaces, the ith folding surface is adjacent to the (i +1) th folding surface, N is a positive integer greater than or equal to 2, and i is a positive integer greater than or equal to 1 and less than or equal to (N-1). The side of the i-th folding surface and the side of the (i +1) -th folding surface are adjacent to each other and present a "<" shape or a ">" shape in a top view. When i is an even number, a cutting line is arranged between the adjacent i-th folding surface and the (i +1) -th folding surface. When i is an odd number, a cutting line may be provided or not provided between the adjacent i-th folding surface and the (i +1) -th folding surface. In the present invention, it is preferable to provide a cutting line between any two adjacent folding surfaces 422, so as to avoid the light incident portion 514 and the edge of the light incident portion 514 from having a crease.

Further, the present embodiment does not limit the folding order of the folding surfaces 422 and the stacking order of the folding surfaces 422 in the stacking portion 510, like the first embodiment.

In the third embodiment, a first included angle θ 1 is respectively formed between the extending direction of the first side edge 4221 of each folding surface 422 and the extending direction of the folding line FL, a second included angle θ 2 is respectively formed between the extending direction of the second side edge 4222 of each folding surface 422 and the extending direction of the folding line FL, and both the first included angle θ 1 and the second included angle θ 2 are greater than 0 degree and smaller than 90 degrees, but not limited thereto. In a variation, each folding surface has a first side and a second side opposite to each other, the first side of one folding surface and the first side of the other folding surface of two adjacent folding surfaces are coupled to the cutting line CL between the two adjacent folding surfaces, the second side of one folding surface and the second side of the other folding surface of two adjacent folding surfaces are coupled to the cutting line CL between the two adjacent folding surfaces, an included angle between an extending direction of one of the first side and the second side of each folding surface and an extending direction of the folding line FL is greater than 0 degree and less than 90 degrees, and the extending direction of the other one of the first side edge and the second side edge of each folding surface and the extending direction of the folding line FL form an included angle of 90 degrees, that is, each folding surface has a bevel edge on one of the two opposite sides, and the other side does not have a bevel edge.

Please refer to fig. 9 and fig. 10. FIG. 9 is a substrate for forming a light guiding film according to a fourth embodiment of the present invention. Fig. 10 is a schematic top view of a light guiding film formed by folding a base material according to a fourth embodiment of the invention and a schematic top view of a light source used in combination with a light emitting device. As shown in FIGS. 9 and 10, the difference between the base material 400' for forming a light guiding film according to the fourth embodiment of the present invention and the base material 400 according to the third embodiment is: a first included angle θ 1 between the extending direction of the first side edge 4221 and the extending direction of the folding line FL of each folding surface 422 is different from a second included angle θ 2 between the extending direction of the second side edge 4222 and the extending direction of the folding line FL, that is, the first included angle θ 1 is different from the second included angle θ 2. For example, the second included angle θ 2 may be smaller than the first included angle θ 1, and the length L3 of the second side 4222 is larger than the length L4 of the first side 4221. The light guiding film 500 'may be formed by stacking the folding surfaces 422 by folding the base material 400' along the folding lines FL. In the formed light guiding film 500', the stack portion 510 includes a plurality of light incident portions 514, and included angles θ a of two light incident portions 514 of the plurality of light incident portions 514 are different and are respectively equal to one and the other of the first included angle θ and the second included angle θ 2. In the present embodiment, the stacking portion 510 includes two light incident portions 514, and an included angle θ a between the two light incident portions 514 is different. In addition, since the included angle θ a between two light incident portions 514 of the plurality of light incident portions 514 is different, the number of light emitting elements LE facing the two light incident portions 514 may also be different (as shown in fig. 10), so that the light guiding film 500 and the light emitting elements LE disposed opposite to the light incident portions 514 of the light guiding film 500 may be applied as the light source 600'. For example, an included angle θ a between the light incident surface 514S of the light incident portion 514 on the right side and the first direction D1 is smaller than an included angle θ a between the light incident surface 514S of the light incident portion 514 on the left side and the first direction D1, so that the length L3 of the light incident surface 514S of the light incident portion 514 on the right side can be greater than the length L4 of the light incident surface 514S of the light incident portion 514 on the left side, and therefore, the number of light emitting elements LE arranged opposite to the light incident surface 514S of the light incident portion 514 on the right side can be greater than the number of light emitting elements LE arranged opposite to the light incident surface 514S of the light incident portion 514 on the left side, but not limited thereto.

According to the embodiment of the invention, the method for forming the light guide film comprises the following steps: first, a substrate according to any of the above embodiments is provided, where the substrate includes a main body portion and a folding portion, where the folding portion of the substrate includes N folding surfaces, the N folding surfaces include 1 st to nth folding surfaces sequentially arranged along a direction, the 1 st folding surface is coupled to the main body portion, or the 1 st folding surface is a folding surface closest to the main body portion among the 1 st to nth folding surfaces, the ith folding surface is adjacent to the (i +1) th folding surface, N is a positive integer greater than or equal to 2, and i is a positive integer greater than or equal to 1 and less than or equal to (N-1). Next, any two adjacent folding surfaces of the N folding surfaces are folded along a folding line therebetween, so that the 1 st to nth folding surfaces are stacked on each other to form a stacked portion. The 1 st to nth folded surfaces in the stacked portion are preferably stacked in order in a top view direction. The present invention does not limit the folding order of the folding faces and the stacking order of the folding faces in the stacking portion. The method of the invention can form the light guide film by simple folding and stacking procedures, and can realize the automation of the production process. In addition, after the folding is completed, the folded portion may be further fixed.

Furthermore, the folds in the above-described embodiments of the invention may be combined with each other to form other embodiments. For example, the substrate for forming the light guiding film may include a main body portion and two folding portions, the two folding portions are respectively located at one side and the other side of the main body portion, one of the two folding portions is similar to the folding portion 120 in the first embodiment or the folding portion 1202 in the second embodiment, and the other of the two folding portions is similar to the folding portion 420 in the third embodiment or the fourth embodiment, but is not limited thereto.

In summary, the light guiding film and the light source using the same, the substrate for forming the light guiding film and the method for forming the light guiding film of the present invention can form the light guiding film by simple folding and stacking processes due to the special folding structure design, and have a short overall light guiding path and good light transmitting and light emitting benefits. In addition, different designs can be carried out on the setting position and the setting angle of the light inlet part according to the requirements of the light outlet brightness, the number of the correspondingly arranged light emitting elements, the image quality and the like, so that the space utilization rate is improved, and meanwhile, the light emitting elements can be arranged in a dispersing way, so that the high temperature problem caused by intensive arrangement is avoided.

The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A substrate for forming a light directing film, comprising:

a main body portion including a light exit region; and

a folded portion located at one side of the main body portion and including:

the folding device comprises a plurality of folding surfaces, wherein at least one cutting line and at least one folding line are arranged between every two adjacent folding surfaces.

2. The substrate of claim 1, wherein each of the folding surfaces has a first side edge, and a first included angle is formed between the extending direction of the first side edge of each of the folding surfaces and the extending direction of the folding line.

3. The substrate of claim 2, wherein each of the folding surfaces further has a second side, the first side and the second side of each of the folding surfaces are opposite to each other, and a second included angle is formed between the extending direction of the second side of each of the folding surfaces and the extending direction of the folding line.

4. The substrate of claim 3, wherein the first included angle is the same or different than the second included angle.

5. The substrate of claim 4, wherein the second included angle is less than the first included angle and the length of the second side is greater than the length of the first side.

6. The substrate of claim 1, wherein two of said cut lines and one of said fold lines are located between two adjacent of said fold planes, said fold line being located between said two cut lines.

7. The substrate of claim 1, wherein there is one said cut line and two said fold lines between two adjacent said fold planes, said cut line being located between said two fold lines.

8. The substrate of claim 1, wherein the folding portion, the folding surfaces, the cutting line and the folding line are defined as a first folding portion, a first folding surface, a first cutting line and a first folding line, respectively, and the substrate further comprises a second folding portion disposed at the other side of the main body portion and comprising a plurality of second folding surfaces, wherein at least one second cutting line and at least one second folding line are disposed between two adjacent second folding surfaces.

9. A light directing film, comprising:

the substrate according to claim 1, wherein said substrate,

wherein the plurality of folding faces are stacked to form a stacking portion, the stacking portion comprising:

a connecting portion; and

the light incident part is positioned on one side of the light incident part, and the light incident part comprises a light incident surface.

10. A light source, comprising:

the light directing film of claim 9; and

at least one light emitting element, wherein the light emitted by the at least one light emitting element is transmitted to the light incident part.

11. A method of forming a light directing film, comprising:

providing the substrate of claim 1; and

folding any two adjacent folding surfaces of the plurality of folding surfaces along the folding lines between each other, so that the plurality of folding surfaces are stacked on each other to form a stacked portion.