TW202021425A - Light bar structure and backlight module - Google Patents

Abstract

A light bar structure includes a flexible substrate, at least one light emitting element, and a back tape. The flexible substrate includes two paired secant lines penetrating the front and back surfaces of the flexible substrate; at least one light-emitting element is disposed on the front surface of the flexible substrate and between the two secant lines, and the area projected at both ends of each secant line is larger than the area projected by the illuminating element on the flexible substrate; the back tape is disposed on the back surface of the flexible substrate, and has a hollow area, and the area of the hollowed area is larger than the area projected by the two ends of the two secant lines, and the position of the two= secant line are in the hollowed area.

Description

Light bar structure and backlight module

A light bar structure, in particular a light bar structure with protection against impact of light-emitting elements, the invention also relates to a backlight module with the light bar structure.

With the advancement of technology, the use of display devices has become quite popular. In the commonly used side-entry backlight module, the electrical substrate as a light source can be divided into a rigid circuit board and a flexible circuit board. Due to the low cost of the flexible circuit board, its flexibility, light and thin structure, etc. Industry favorite.

Traditionally, the flexible circuit board is fixed on the side wall of the back cover by adhesive strips, and the positioning technology is used to maintain a certain distance from the light guide plate to exert stable optical performance and taste.

However, under long-term use, the light guide plate may encounter environmental temperature changes or absorb moisture and expand. When the above distance is insufficient, the light guide plate may strike or squeeze the light-emitting element on the flexible circuit board, causing the light-emitting element Damaged, which in turn affects optical performance.

The invention provides a light bar structure according to an embodiment, which includes a flexible substrate, at least one light-emitting element, and a glue. The flexible substrate includes two pairs of cutting lines penetrating the front and back sides of the flexible substrate; at least one light-emitting element is disposed on the front of the flexible substrate and is located between the two cutting lines, and the ends of each cutting line are projected from each other The area is larger than the area of the light-emitting device projected on the flexible substrate; the adhesive is provided on the back of the flexible substrate, which has a hollow area, the area of the hollow area is greater than the area formed by the projection of the two ends of the two secant lines, and two The position of the secant line is in the hollow area.

As in the above-mentioned backlight module, in one embodiment, the light bar structure includes a plurality of light-emitting elements, which are arranged along the lateral direction and at intervals; the flexible substrate includes a plurality of pairs of secant lines, which are spaced apart along the lateral direction, of which a plurality of pairs The position of the secant line is located in the hollowed-out area, and each light-emitting element is located between a pair of secant lines.

As in the light bar structure described above, in one embodiment, the cutting line extends in the lateral direction.

As in the above-mentioned light bar structure, in one embodiment, the cutting line extends longitudinally in a direction different from the lateral direction.

As described above, in one embodiment, the light bar structure includes a plurality of light-emitting elements, and the flexible substrate includes a plurality of pairs of cutting lines and a plurality of hollow areas, and the positions of the pairs of cutting lines are located at In one of the hollowed-out areas, each light-emitting element is located between a pair of secant lines.

As in the above-mentioned light bar structure, in one embodiment, the following equation is satisfied: X ≥ 2T+L, where X is the extension length of the secant line, T is the thickness of the adhesive, and L is the extension length of each light-emitting element.

The present invention also provides a backlight module according to an embodiment, which includes the light bar structure and the light guide plate as described above. The light guide plate is located on one side of the light bar structure. The light guide plate includes a light incident surface, and the light incident surface faces at least one light emitting element.

As described above, in one embodiment, the backlight module further includes a reflective plate located on the bottom surface of the light guide plate.

As described above, in one embodiment, the backlight module further includes a back cover. The light bar structure, the light guide plate and the reflective plate are disposed in the back cover. The back cover includes an inner wall surface, and the back adhesive is attached to the inner wall surface.

Through the light bar structure and the backlight module provided by one embodiment and multiple embodiments of the present invention, the optical performance of the applied display device can exert the original optical taste under long-term use, and can effectively reduce the light emission. The risk of the element being damaged due to the impact of the light guide plate effectively solves the problems encountered by the prior art.

Please refer to FIGS. 1 to 3. FIG. 1 is a front view of the first embodiment of the light bar structure of the present invention. FIG. 2 is a schematic view (1) of the use state of an embodiment of the backlight module of the present invention. FIG. 3 is a schematic view (2) of the use state of an embodiment of the backlight module of the present invention. The light bar structure 1 includes a flexible substrate 11, at least one light emitting element 12 and a glue 13. The flexible substrate 11 such as a flexible circuit board is used for the light-emitting element 12 to be disposed thereon, and provides the necessary printed circuit to provide power to the light-emitting element 12. The light-emitting element 12 may be, but not limited to, an LED (Light-emitting diode) to project light. The back adhesive 13 may be a double-sided adhesive, one side is adhered to the flexible substrate 11 and the other side is adhered to the fixed structure (such as the back cover 4 of FIG. 2 and FIG. 3) to fix the flexible substrate 11 to the fixed structure.

As shown in FIGS. 1, 2 and 3, the flexible substrate 11 includes two pairs of cutting lines 111, and the cutting lines 111 penetrate the front surface 11 a and the back surface 11 b of the flexible substrate 11. The light-emitting element 12 is disposed on the front surface 11 a of the flexible substrate 11 and is located between the two secant lines 111. As shown in FIG. 1, the area A1 formed by the projections of both ends of each secant 111 is larger than the area of the light-emitting element 12 projected on the flexible substrate 11.

As shown in FIGS. 1, 2 and 3, the back adhesive 13 is provided on the back surface 11 b of the flexible substrate 11 in an adhesive manner. The adhesive 13 has a hollowed-out area A2, that is, a hollowed-out area. The area of the hollowed-out area A2 is larger than the area A1 formed by the projections of the two ends of the second cut line 111, and the position of the second cut line 111 is located in the hollow area A2. With this structure, when the flexible substrate 11 is adhered to the fixing structure with the adhesive 13 (as shown in the back cover 4 of FIG. 2 and FIG. 3 ), the portion of the flexible substrate 11 between the two cut lines 111 is in a floating state, and the The fixed structure maintains a gap; the gap is equivalent to the thickness T of the back adhesive 13. Therefore, the movement of the light-emitting element 12 is buffered and can be displaced toward the fixed structure. When the light guide plate 2 may be pressed toward the light-emitting element 12 due to thermal expansion, the light-emitting element 12 may be moved toward the fixed structure due to pressure (as shown in FIGS. 2 and 2) 3 The back cover 4) moves to reduce and buffer the positive pressure, so as to prevent the light emitting element 12 from being damaged due to the pressure and affecting the optical taste of the light bar structure 1.

2 and FIG. 3 again, based on the aforementioned light bar structure 1, the present invention further provides a backlight module 100. The backlight module 100 includes a light bar structure 1, a light guide plate 2, a reflection plate 3 and a back cover 4. The light bar structure 1 may be the light bar structure 1 of any example in the embodiments of the present invention. The light bar structure 1, the light guide plate 2 and the reflective plate 3 are disposed in the back cover 4, the back cover 4 includes an inner wall surface 41, and the back adhesive 13 is attached to the inner wall surface 41. The light guide plate 2 is located on one side of the light bar structure 1. The light guide plate 2 includes a light incident surface, and the light incident surface faces the light emitting element 12. The reflective plate 3 is located on the bottom surface of the light guide plate 2.

2 shows a state in which the backlight module 100 is not in use, a certain gap is left between the light emitting element 12 and the light guide plate 2, and a gap is also left between the light emitting element 12 and the inner wall surface 41 (about a Thickness T).

As shown in FIG. 3, the backlight module 100 is used for a period of time. The light guide plate 2 expands due to the thermal environment or expands due to the absorption of moisture. The lateral expansion develops and impacts and squeezes the light emitting element 12. Due to the existence of the gap, the light-emitting element 12 moves toward the hollow area A2 after being pressed by the light guide plate 2 without being directly clamped and pressed against the light guide plate 2 and the inner wall surface 41, effectively reducing and buffering the pressure force, avoiding Damage, so that the light-emitting element 12 can still play a certain performance of optical performance.

Please refer to FIG. 4, which is a front view of a second embodiment of the light bar structure of the present invention. In this embodiment, the difference from the first embodiment shown in FIG. 1 is the shape of the hollow area A2. The hollowed-out area A2 of the first embodiment shown in FIG. 1 is in a block shape, such as a rectangle, which is hollowed out only in a part of the back adhesive 13 and may include a cutting line 111. The hollowed-out area A2 shown in FIG. 2 is a band-shaped hollow, and the middle part of the back adhesive 13 is entirely removed. With this structural design, the purpose of protecting the light-emitting element 12 can also be achieved.

Please refer to FIG. 5, which is a front view of a third embodiment of the light bar structure of the present invention. The difference from the above embodiments shown in FIGS. 1 and 4 is that the adhesive 13 has a plurality of hollow regions A2, and adjacent hollow regions A2 are arranged at intervals. The two pairs of cutting lines 111 are a cutting line group, and each cutting line group is located in each hollow area A2, and each light-emitting element 12 is located between each pair of cutting lines 111. The hollow area A2 and the light-emitting elements 12 are spaced apart along a lateral D direction, and the pair of cutting lines 111 are spaced apart along the lateral D direction. With this structural design, the above-mentioned purpose of avoiding damage to the light guide plate 2 caused by the light guide plate 2 hitting the light emitting element 12 can also be achieved.

Due to the cable design of the display device or the light-emitting device used in the light bar structure 1, the industry may use the horizontal direction D to cut the cutting line 111, as shown in the embodiment shown in FIGS. 1 to 3, the cutting line 111 extends along the horizontal direction D . However, the present invention is not limited to this. In some embodiments, the cutting line 111 may also be cut in a different direction from the above horizontal D, for example, cut in a longitudinal direction (not shown), depending on the industry Setting method.

In addition, as shown in FIG. 5, in order to protect the light emitting element 12 described above, the thermal expansion of the light guide plate 2 or other factors are prevented from hitting the light emitting element 12 and causing damage. In these embodiments, the extension length of the cutting line 111, the thickness of the adhesive 13 and the extension length of the light emitting element 12 satisfy the following equation: X ≥ 2T+L, where X is the extension length of the cutting line 111, and T is the length of the adhesive 13 The thickness (please refer to FIG. 7 or FIG. 8 ), L is the extension length of each light-emitting element 12, and the extension direction of the cutting line 111 and the extension direction of the light-emitting element 12 are the same direction.

In addition, regarding the type of the cutting line 111, the present invention is not limited to a straight line. Please refer to FIGS. 6 to 8, which are schematic views of an embodiment of the cutting line 111 of the light bar structure 1 of the present invention. As shown in FIG. 6, the cutting line 111 is an opposite arc; as shown in FIG. 7, the cutting line 111 may be a wavy line; as shown in FIG. 8, the cutting line 111 has bent portions at both ends. In the embodiment shown in FIG. 8 The bent portion extends toward the outside, and in some embodiments, the bent portion extends toward the inside. In other words, the present invention is not limited to the cutting line 111 type shown in the above diagram, and different cutting line 111 types are adopted depending on the needs and design of the industry.

Through the above one or more embodiments of the present invention, the light bar structure is provided so that the applied display device will not be damaged due to long-term use of the light guide plate or other optical film to expand and hit the light-emitting element, thereby destroying the optical which performed. In other words, in one or more embodiments, the light bar structure can effectively reduce the risk of the light emitting element being damaged due to the impact of the light guide plate. In addition, a backlight module according to an embodiment of the present invention, having the above-mentioned light bar structure, also has the above-mentioned advantages.

100: Backlight module 1: Light bar structure 11: Flexible substrate 11a: Front 11b: Rear 111: Secant 12: Light emitting element 13: Adhesive 2: Light guide plate 3: Reflector 4: Back cover 41: Inner wall surface A1 : Projection area A2: Hollow-out area D: Lateral L: Extension length T: Thickness X: Extension length

[FIG. 1] It is a front view of the first embodiment of the light bar structure of the present invention. [FIG. 2] It is a schematic view (1) of the use state of one embodiment of the backlight module of the present invention. [FIG. 3] It is a schematic view (2) of the use state of an embodiment of the backlight module of the present invention. [Fig. 4] It is a front view of the second embodiment of the light bar structure of the present invention. [FIG. 5] This is a front view of a third embodiment of the light bar structure of the present invention. [Fig. 6] It is a schematic diagram of an embodiment of the cutting line of the light bar structure of the present invention. [Fig. 7] It is a schematic diagram of an embodiment of the cutting line of the light bar structure of the present invention. [FIG. 8] It is a schematic diagram of an embodiment of the cutting line of the light bar structure of the present invention.

1: Light bar structure

11: Flexible substrate

11a: positive

111: secant

12: Light emitting element

13: Adhesive

A1: Projected area

A2: Hollow area

Claims (9)

A light bar structure includes: a flexible substrate including two pairs of cutting lines penetrating a front surface and a back surface of the flexible substrate; at least one light-emitting element disposed on the front surface of the flexible substrate and Located between the secant lines, the area formed by the projections of the two ends of the secant lines is greater than the area of the at least one light-emitting element projected on the flexible substrate; and a glue is provided on the flexible substrate The back side; the adhesive has a hollow area, the area of the hollow area is larger than the area formed by the projections of the two ends of the cut lines, and the positions of the cut lines are located in the cut area. The light bar structure according to claim 1, wherein the light bar structure comprises a plurality of light-emitting elements arranged along a lateral direction and spaced apart; the flexible substrate comprises the pairs of pairs of secant lines, spaced along the lateral space, wherein The positions of the multiple pairs of cutting lines are located in the hollow area, and each of the light-emitting elements is located between one of the cutting lines. The light bar structure according to claim 2, wherein the secant line extends along the lateral direction. The light bar structure according to claim 2, wherein the secant line extends in a longitudinal direction different from the lateral direction. The light bar structure according to claim 1, wherein the light bar structure includes a plurality of light-emitting elements, and the flexible substrate includes the plurality of pairs of secant lines and a plurality of hollow areas, the plurality of pairs of secant lines The positions are respectively located in one of the hollow regions, and each of the light-emitting elements is respectively located between a pair of secant lines. The light bar structure described in claim 1 satisfies the following equation: X ≥ 2T+L, where X is an extension of the secant, T is a thickness of the adhesive, and L is an extension of each light-emitting element length. A backlight module, comprising: the light bar structure according to any one of claims 1 to 6; and a light guide plate located on one side of the light bar structure, the light guide plate including a light incident surface, the light incident surface Facing the at least one light emitting element. The backlight module according to claim 7, further comprising a reflective plate located on a bottom surface of the light guide plate. The backlight module according to claim 8, further comprising a back cover, the light bar structure, the light guide plate and the reflection plate are disposed in the back cover, the back cover includes an inner wall surface, and the back adhesive is attached to The inner wall surface.

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