Backlight module and display device

Abstract

A backlight module includes a light-emitting element and a light guide plate. The light guide plate has a light-incident surface, a light-emitting surface, a plurality of light guide pillars, and a plurality of light-emitting structures. The light-incident surface faces the light-emitting element, and the light-emitting surface is connected to the light-incident surface. Each light guide pillar protrudes from the light-emitting surface. The extending direction of each light guide pillar is parallel to the normal direction of the light-incident surface, and the light guide pillars are arranged along a direction parallel to the light-incident surface. Each light-emitting structure protrudes from the light-emitting surface and is located between any two adjacent light guide pillars. The present invention also provides a display device having the above-described backlight module.

Description

Technical Field

[0001] The present invention relates to a light source module, particularly a backlight module, and a display device having the aforementioned backlight module. Prior Technology

[0002] Generally, most display devices are equipped with light-emitting elements, and the light beams generated by these elements form images. Depending on the different positions of the light-emitting elements in the backlight module, backlight modules can be divided into edge-lit backlight modules and direct-lit backlight modules, with edge-lit backlight modules having the advantage of being thinner.

[0003] However, in edge-lit backlight modules, because the light beams from the light-emitting elements enter from the side of the light guide plate, uneven brightness is prone to occur on the side of the light guide plate. For example, when the spacing between the light-emitting elements is too large, obvious dark lines easily appear at the edge of the light guide plate. Conversely, when the spacing between the light-emitting elements is too small, obvious bright lines easily appear at the edge of the light guide plate.

[0004] The "Prior Art" paragraph is only used to help understand the content of this invention. Therefore, the content disclosed in the "Prior Art" paragraph may include some prior art that is not known to those skilled in the art. The content disclosed in the "Prior Art" paragraph does not mean that the content or the problem to be solved by one or more embodiments of this invention was known or recognized by those skilled in the art prior to this application. Summary of the Invention

[0005] This invention provides a backlight module to improve light emission uniformity and optical quality.

[0006] The present invention provides a display device to improve image quality.

[0007] Other objects and advantages of the present invention can be further understood from the technical features disclosed herein.

[0008] To achieve one, some, or all of the above-mentioned objectives, or other objectives, an embodiment of the present invention provides a backlight module, including a light-emitting element and a light guide plate. The light guide plate has a light-incident surface, a light-emitting surface, a plurality of light guide pillars, and a plurality of light-emitting structures. The light-incident surface faces the light-emitting element, and the light-emitting surface is connected to the light-incident surface. Each light guide pillar protrudes from the light-emitting surface. The extension direction of each light guide pillar is parallel to the normal direction of the light-incident surface, and the light guide pillars are arranged along a direction parallel to the light-incident surface. Each light-emitting structure protrudes from the light-emitting surface and is located between any two adjacent light guide pillars.

[0009] In one embodiment of the present invention, the plurality of light guide pillars described above can be connected to each other in a direction, and a groove is formed between any two adjacent light guide pillars. The light emitting structure is located on the groove, and the orthographic projection of the light emitting structure onto the light emitting surface at least partially overlaps with the orthographic projection of the light guide pillar onto the light emitting surface.

[0010] In one embodiment of the present invention, the plurality of light guide pillars are spaced apart from each other in a direction, and a groove is formed between any two adjacent light guide pillars. The light-emitting structure is located on the groove, and the width of each light guide pillar in the direction is W1. The spacing between any two adjacent light guide pillars in the direction is P1, where W1 ≦ P1 ≦ 5 * W1.

[0011] In one embodiment of the present invention, the light-emitting surface has a non-display area and a display area, with the non-display area located between the light-incident surface and the display area. The light-emitting structure may be located within the non-display area.

[0012] In one embodiment of the present invention, the above-mentioned light-emitting structures are arranged in a first row of light-emitting structures and a second row of light-emitting structures along the direction, and the first row of light-emitting structures and the second row of light-emitting structures are spaced apart in the normal direction of the incident light surface.

[0013] In one embodiment of the present invention, the width of each of the above-mentioned light-emitting structures in the normal direction of the light-incident surface is W2, and the distance between the first row of light-emitting structures and the second row of light-emitting structures in the normal direction of the light-incident surface is P2. 2*W2≦P2.

[0014] In one embodiment of the present invention, the light-emitting surface has a non-display area and a display area, with the non-display area located between the light-incident surface and the display area. Multiple light guide pillars are located within the non-display area, or multiple light guide pillars are located in both the non-display area and the display area.

[0015] In one embodiment of the present invention, the length of the light guide plate in the normal direction of the light incident surface is L, and the lengths of the plurality of light guide pillars in the normal direction of the light incident surface are L1, respectively. 1 mm ≤ L1 ≤ L.

[0016] In one embodiment of the present invention, each of the above-described light guide pillars may further have a light guide surface. Each light guide surface is connected to the light emitting surface, and the included angle between each light guide surface and the light emitting surface is A1. 20°≦A1≦75°.

[0017] In one embodiment of the present invention, each of the above-described light-emitting structures further includes a surface. The surface is connected to the light-emitting surface, and the included angle between each surface and the light-emitting surface is A2. 20°≦A2≦75°.

[0018] In one embodiment of the present invention, each of the above-described light guide pillars may further have a first top, and the first top faces away from the light emitting surface. The height of each light guide pillar between each first top and the light emitting surface is H1, where 2 µm ≤ H1 ≤ 40 µm.

[0019] In one embodiment of the present invention, each of the above-described light-emitting structures may further have a second top, and the second top faces away from the light-emitting surface. The height of each light-emitting structure between each second top and the light-emitting surface is H2, where 2 µm ≤ H2 ≤ 40 µm.

[0020] In one embodiment of the present invention, each of the light guide pillars may further have a first top, and the first top faces away from the light emitting surface. Each light emitting structure may further have a second top, and the second top faces away from the light emitting surface. The second top is offset from the first top in the normal direction of the light emitting surface.

[0021] In one embodiment of the present invention, the width of each of the above light guide pillars in the direction is W1, 10 µm ≤ W1 ≤ 150 µm.

[0022] In one embodiment of the present invention, the width of each of the above-described light-emitting structures in the normal direction of the light-incident surface is W2, 10 µm ≤ W2 ≤ 150 µm.

[0023] In one embodiment of the present invention, the plurality of light guide pillars and light emission structures described above each have a light guide surface protruding from the light emission surface, and the light guide surface of each light guide pillar and light emission structure includes at least one of curved surface and flat surface.

[0024] In one embodiment of the present invention, the light-emitting element includes a plurality of light-emitting units, and each light-emitting unit may be located between any two adjacent light guide pillars in their extension directions.

[0025] In one embodiment of the present invention, the light-emitting structures described above can be arranged in a row along the direction to form a light-emitting structure, and the length of the row of light-emitting structures in the direction is L2. The width of the light guide plate in the direction is W, and L2 = W.

[0026] To achieve one, some, or all of the above objectives, or other objectives, an embodiment of the present invention provides a display device, including a display panel and the aforementioned backlight module. The backlight module and the display panel are disposed opposite to each other.

[0027] The backlight module of this invention employs a light guide plate with light guide pillars and a light emission structure. The light guide pillars guide the light beam from the light-emitting element to propagate approximately along its extension direction, and a portion of the light beam is refracted from opposite sides of the light guide pillars approximately parallel to the incident light surface during propagation, thereby enhancing the light mixing effect of the light beam on the light guide plate. On the other hand, the light emission structure guides the light beam from the light-emitting element to increase the local brightness on the light emission surface, thereby suppressing the generation of dark lines. Therefore, the backlight module of this invention effectively improves the light emission uniformity and optical quality of the light guide plate. The display device of this invention employs the aforementioned backlight module, thus improving image quality.

[0028] To make the above and other objects, features and advantages of the present invention more apparent and understandable, specific embodiments are described below in conjunction with the accompanying drawings for detailed explanation. Simple Explanation of the Diagram

[0029] Figure 1 is a cross-sectional schematic diagram of a backlight module according to an embodiment of the present invention. Figure 2 is a schematic diagram of the light guide plate in Figure 1. Figure 3 is a top view of the light guide plate and light-emitting element in Figure 1. Figure 4 is a partial cross-sectional view of the backlight module in Figure 3 along the C1-C1 section line. Figure 5 is a cross-sectional view of the backlight module in Figure 3 along the C2-C2 section line. Figure 6 is a schematic diagram of the light guide plate and a cross-sectional schematic diagram of the light guide column of another embodiment of the backlight module of the present invention. Figure 7 is a diagram showing the relationship between the illuminance of the light guide plate of the backlight module in the non-display area and the horizontal position according to another embodiment of the present invention. Figure 8 is a top view of the light guide plate of a backlight module according to another embodiment of the present invention. Figure 9 is a top view of the light guide plate of a backlight module according to another embodiment of the present invention. Figure 10 is a cross-sectional schematic diagram of a display device according to an embodiment of the present invention. Implementation

[0030] The foregoing descriptions and other technical contents, features, and effects of this invention will be clearly presented in the following detailed description of a preferred embodiment with reference to the accompanying drawings. The directional terms mentioned in the following embodiments, such as up, down, left, right, front, or back, are merely for reference to the accompanying drawings. Therefore, the directional terms used are for illustrative purposes and not for limiting the invention.

[0031] Figure 1 is a cross-sectional schematic diagram of a backlight module according to an embodiment of the present invention. Figure 2 is a schematic diagram of the light guide plate of Figure 1. Figure 3 is a top view of the light guide plate and the light-emitting element of Figure 1. Figure 4 is a partial cross-sectional schematic diagram of the backlight module of Figure 3 along the C1-C1 section line. Figure 5 is a cross-sectional schematic diagram of the backlight module of Figure 3 along the C2-C2 section line. Referring to Figures 1, 2, and 3, the backlight module 100 includes a light-emitting element 110 and a light guide plate 120. The light guide plate 120 has a light-incident surface 121, a light-emitting surface 122, a plurality of light guide pillars 123, and a plurality of light-emitting structures 124. The light-incident surface 121 faces the light-emitting element 110, and the light-emitting surface 122 is connected to the light-incident surface 121. Each light guide pillar 123 protrudes from the light-emitting surface 122. The extension direction X of each light guide post 123 is parallel to the normal direction N of the light incident surface 121, and the light guide posts 123 are arranged along the arrangement direction Y, which is parallel to the light incident surface 121. Each light emitting structure 124 protrudes from the light emitting surface 122 and is located between any two adjacent light guide posts 123. In this embodiment, the normal direction N is, for example, opposite to the extension direction X.

[0032] Referring to Figure 3, the light-emitting element 110 may include multiple light-emitting units 111, and each light-emitting unit 111 may be located between any two adjacent light guide pillars 123 in the extension direction X. That is, on a reference plane parallel to the arrangement direction Y and the normal direction Z, the orthographic projections of the multiple light-emitting units 111 onto the reference plane and the orthographic projections of the multiple light guide pillars 123 onto the reference plane are staggered along the arrangement direction Y. For example, each light-emitting unit 111 may be located opposite two light guide pillars 123 in the extension direction X, so that the light beams B1 and B2 generated by each light-emitting unit 111 can be incident into at least two light guide pillars 123. In one embodiment, the light beam generated by at least one light-emitting unit 111 may be incident into three or more light guide pillars 123. Incidentally, in this embodiment, the light guide pillars 123 may be generally semi-cylindrical, and the extension direction X may be substantially parallel to the axis of the semi-cylindrical pillar. Each light-emitting unit 111 may include one or more light-emitting diodes (LEDs). Furthermore, the emission wavelength of the light-emitting diode may include the wavelength range of blue light or white light, but the present invention does not impose further limitations on this. In this embodiment, the distance between any two adjacent light-emitting units 111 is, for example, 2 mm to 3 mm. The angle subtended by the light beam of each light-emitting unit 111 in the extension direction X and the normal direction Z is, for example, ±60 degrees.

[0033] Referring again to Figures 2 and 3, the light guide plate 120 of this embodiment may also have a plate body 125, and the light guide post 123, the light emitting structure 124, and the plate body 125 may be an integral structure. For example, the light guide plate 120 may be manufactured by thermoforming or injection molding. The material of the light guide plate 120 may include plastic, glass, or other materials suitable for light transmission. For example, in this embodiment, the material of the light guide plate 120 may include polymethyl methacrylate (PMMA); in other embodiments, the material of the light guide plate 120 may include cycloolefin polymer (COP) or polycarbonate (PC).

[0034] Please continue referring to Figure 3. In this embodiment, the multiple light guide pillars 123 can be connected to each other in the Y-direction, and a groove 126 (also shown in Figures 2 and 4) is formed between any two adjacent light guide pillars 123. The light emitting structure 124 is located on the groove 126, and the orthographic projection OP1 of the light emitting structure 124 on the light emitting surface 122 at least partially overlaps with the orthographic projection OP2 of the light guide pillar 123 on the light emitting surface 122. The orthographic projection OP1 is the outline of the light emitting structure 124 shown in Figure 3, and the orthographic projection OP2 is the outline of the light guide pillar 123 shown in Figure 3. For example, approximately half of the area of ​​the orthographic projection OP1 of the light emitting structure 124 may overlap with a portion of the orthographic projection OP2 of one of the two adjacent light guide pillars 123, and the other half of the area of ​​the orthographic projection OP1 may overlap with a portion of the orthographic projection OP2 of the other of the two adjacent light guide pillars 123. In other words, the orthographic projection OP1 of the light-emitting structure 124 will not completely overlap with the entire orthographic projection OP2 of one of the light guide pillars 123. In the arrangement direction Y, multiple light guide pillars 123 and multiple light-emitting structures 124 are arranged alternately. On the reference plane parallel to the extension direction X and the arrangement direction Y, multiple light guide pillars 123 and multiple light-emitting structures 124 form multiple microstructures protruding from the light-emitting surface 122. This can improve the problem of uneven brightness and darkness and improve the light emission uniformity of the light guide plate 120.

[0035] Referring to Figures 3 and 4, each light guide post 123 may also have a first top T1, with the first top T1 facing away from the light emitting surface 122. Each light emitting structure 124 may also have a second top T2, with the second top T2 facing away from the light emitting surface 122. The second top T2 is offset from the first top T1 in the normal direction Z of the light emitting surface 122. In detail, the first top T1 may be the highest part of the light guide post 123 protruding from the light emitting surface 122, and the second top T2 may be the highest part of the light emitting structure 124 protruding from the light emitting surface 122. Since the light emitting structure 124 can guide the light beam outward, the second top T2 can be offset from the first top T1 in the normal direction Z to avoid excessive light beams from the light guide post 123 escaping from the second top T2 of the light emitting structure 124, thereby improving the optical effect of the light guide post 123. Please continue referring to Figure 4. The width of each light guide post 123 in the arrangement direction Y is W1, and the distance between any two adjacent light guide posts 123 in the arrangement direction Y is P1. In this embodiment, P1 = W1. Specifically, the distance P1 can be the distance between two adjacent first tops T1.

[0036] FIG. 6 is a schematic diagram of a light guide plate and a cross-sectional schematic diagram of a light guide column of a backlight module according to another embodiment of the present invention. Please first refer to FIGS. 4 and 5. The light guide column 123 has a light guide surface GS1 protruding from the light emitting surface 122, and the light emitting structure 124 has a light guide surface GS2 protruding from the light emitting surface 122. The light guide surface GS1 of each light guide column 123 and the light guide surface GS2 of each light emitting structure 124 may include at least one of a curved surface and a flat surface. For example, the light guide surfaces GS1 and GS2 of this embodiment are curved surfaces protruding from the light emitting surface 122. Therefore, the light guide surfaces GS1 and GS2 also have the effect of diverging light, thereby further improving the light emission uniformity of the light guide plate 120.

[0037] In other embodiments, the light guide surfaces GS1 and GS2 may include flat surfaces. For example, please refer to FIG. 6. The light guide column 123a in embodiment (a) may be generally triangular prism-shaped, and the light guide surface GS1a of the light guide column 123a may include two connected flat surfaces. Similarly, the light guide column 123b in embodiment (b) may be polygonal prism-shaped, and the light guide surface GS1b may include six flat surfaces; the light guide column 123c in embodiment (c) may be trapezoidal prism-shaped, and the light guide surface GS1c may include three flat surfaces. In another embodiment, as shown in embodiment (d) of FIG. 6 for example, the light guide column 123d may be a column with rounded corners, and the light guide surface GS1d may include a flat surface and a curved surface. Similarly, in other embodiments, the light guide surface of the light emitting structure 124 may include a flat surface, or may include a flat surface and a curved surface at the same time.

[0038] Please first refer to FIGS. 1 and 3. In this embodiment, in addition to guiding the light beam to exit substantially along the arrangement direction Y (or the direction opposite to the arrangement direction Y) (such as the light beam B1), the light guide column 123 can also guide the light beam to be transmitted substantially along the direction X (such as the light beam B2). Further, the light emitting surface 122 has a non-display area AA and a display area DA (both are also marked in FIG. 2), and the non-display area AA is located between the light incident surface 121 and the display area DA. The light guide column 123 may be located in the non-display area AA to transmit more light beams B2 from the non-display area AA to the display area DA, thereby improving the light utilization rate. Specifically, the length of the light guide plate 120 in the normal direction N of the light incident surface 121 is L (marked in FIG. 1), and the length of the light guide column 123 in the normal direction N of the light incident surface 121 is L1. 1 mm ≤ L1 < L. For example, the length of the non-display area AA in the normal direction N is L0, and the length L0 is greater than 1 mm; since the light guide column 123 is located in the non-display area AA and does not extend to the display area DA, the range of L1 can be: 1 mm ≤ L1 ≤ L0.

[0039] Referring again to Figure 4, the light-guiding surface GS1 of each light guide post 123 is connected to the light-emitting surface 122, and the included angle between each light guide surface GS1 and the light-emitting surface 122 is A1. Where 20°≦A1≦75°, this increases the light output of the light guide post 123 and makes it easier to manufacture. It should be noted that the light guide surface GS1 in this embodiment is curved; therefore, the included angle A1 can be the angle between the cross-section of the connection between the light guide surface GS1 and the light-emitting surface 122 and the light-emitting surface 122. Furthermore, the height of each light guide post 123 between each first top T1 and the light-emitting surface 122 is H1, 2 µm≦H1≦40 µm (micrometers). On the other hand, the width of each light guide post 123 in the arrangement direction Y is W1, 10 µm≦W1≦150 µm. It is understandable that the height H1 and width W1 of each light guide post 123 can be changed according to the included angle A1.

[0040] Referring to Figures 3 and 5, the light-emitting structure 124 can change the path of the light beam, guiding the light beam B3 out of the light guide plate 120. Therefore, the light-emitting structure 124 can improve the local brightness of the light-emitting surface 122 to compensate for the limitations of the optical effect of the light guide column 123. Specifically, because the light beams B1 and B2 need to travel a certain distance within the light guide column 123 approximately along the extension direction X before exiting the light guide column 123, the light guide column 123 may have insufficient light mixing effect on the side near the light incident surface 121. Furthermore, since the light guide column 123 is cylindrical in shape, and the light guide surface GS1 is the circumferential surface of the cylinder, the angle at which the light beam B1 exits from the light guide column 123 is limited, which also causes insufficient light mixing effect on the side of the light guide column 123 near the light incident surface 121. Based on the above, the light-emitting structure 124 can be set in the area of ​​the light-emitting surface 122 where the light-guiding column 123 has insufficient light mixing effect, or in the area of ​​the light-emitting surface 122 where dark patterns are more likely to occur. In this embodiment, the light guide plate 120 uses a two-dimensional diffused light structure design with the extension direction of each light guide column 123 being the extension direction X and the arrangement direction of the multiple light-emitting structures 124 being the arrangement direction Y, to improve the light emission uniformity and optical quality of the light guide plate 120.

[0041] For example, in this embodiment, the light-emitting structure 124 can be located within the non-display area AA to improve the light emission uniformity and optical quality of the non-display area AA. Specifically, because the non-display area AA is closer to the light-incident surface 121 than the display area DA, the probability of dark patterns appearing in the non-display area AA may be higher than in the display area DA. However, the specific position of the light-emitting structure 124 can be changed according to actual needs. Referring to Figure 3, in this embodiment, the light-emitting structure 124 can be arranged along the arrangement direction Y to form a light-emitting structure 1240, and the length of the light-emitting structure 1240 in the arrangement direction Y is L2. The width of the light guide plate 120 in the arrangement direction Y is W, and L2 = W. In other words, the light-emitting structure 124 can be arranged along the arrangement direction Y from edge E2 to edge E3 of the light-emitting surface 122 to increase the local brightness of the light-emitting surface 122 along the arrangement direction Y.

[0042] Furthermore, the light-emitting structures 124 can be arranged along the arrangement direction Y to form a first row of light-emitting structures 1241 and a second row of light-emitting structures 1242, and the first row of light-emitting structures 1241 and the second row of light-emitting structures 1242 are separated in the normal direction N of the incident surface 121. In this way, the light beam can be dispersed from the first row of light-emitting structures 1241 and the second row of light-emitting structures 1242 out of the light guide plate 120, so as to avoid a large amount of superposition of the light beams emitted from the first row of light-emitting structures 1241 and the second row of light-emitting structures 1242, thereby further improving the light emission uniformity and optical quality of the light guide plate 120. Referring again to Figure 5, the width of each light-emitting structure 124 in the normal direction N of the incident surface 121 is W2, and the distance between the first row of light-emitting structures 1241 and the second row of light-emitting structures 1242 in the normal direction N of the incident surface 121 is P2. 2*W2≦P2, thus further reducing the superposition of light beams emitted from the first row of light-emitting structures 1241 and the second row of light-emitting structures 1242, achieving better optical effects. It is understood that this embodiment uses two rows of light-emitting structures 1240 (i.e., the first row of light-emitting structures 1241 and the second row of light-emitting structures 1242) as an example, but in one embodiment, the light-emitting structures 124 can be arranged in one row.

[0043] Referring to Figures 2 and 5, in this embodiment, each light-emitting structure 124 also has a surface S2. Surface S2 is connected to the light-emitting surface 122, and the angle between each surface S2 and the light-emitting surface 122 is A2. Where 20°≦A2≦75°, this can further increase the light output of the light-emitting structure 124 and also make the light-emitting structure 124 easier to manufacture. It should be noted that the surface S2 in this embodiment is the same as the light-guiding surface GS2. On the other hand, the height of each light-emitting structure 124 between each second top T2 and the light-emitting surface 122 is H2, 2 µm≦H2≦40 µm. Furthermore, the width W2 of each light-emitting structure 124 can be in the range of 10 µm≦W2≦150 µm. Similarly, the height H2 and width W2 of each light-emitting structure can be changed according to the angle A2.

[0044] Compared to conventional technology, the backlight module 100 of this embodiment employs a light guide plate 120 having a light guide post 123 and a light emission structure 124. The light guide post 123 can be used to guide the light beams B1 and B2 of the light-emitting element 110 to propagate approximately along the extension direction X (for example, the opposite sides of the light guide post 123 can reflect the light beams B1 and B2, causing the light beams B1 and B2 to propagate approximately along the extension direction X). During the propagation process, the light beam (e.g., light beam B2) may also be refracted from the opposite sides of the light guide post 123 (approximately along the positive and negative alignment direction Y). That is, the light beam incident on the light guide post 123 can produce the optical characteristic that part of the light beam is refracted and part of the light beam is reflected, thereby improving the light mixing effect of the light guide plate 120 in the alignment direction Y, which is substantially parallel to the light incident surface 121. On the other hand, the light emission structure 124 can guide the light beam of the light-emitting element 110 to exit the light guide plate 120 earlier, so as to suppress the generation of dark patterns on the light guide plate 120. Therefore, the backlight module 100 in this embodiment can effectively improve the light emission uniformity and optical quality of the light guide plate 120.

[0045] Figure 7 is a diagram showing the relationship between the illuminance and horizontal position of the light guide plate in the non-display area of ​​another embodiment of the backlight module of the present invention. Referring to Figures 3 and 7, it should be noted that (a) of Figure 7 is an illuminance distribution diagram at a distance of 1 mm from the light-incident surface 121 along the extension direction X of the non-display area AA, and (b) is an illuminance distribution diagram at a distance of 2 mm from the light-incident surface 121 along the extension direction X of the non-display area AA. Furthermore, the horizontal position is the coordinate along the arrangement direction Y within the non-display area AA, and the horizontal position in Figure 7 equal to zero corresponds to the midpoint of the non-display area AA in the arrangement direction Y. As mentioned above, the light guide column 123 can guide the light beam to exit approximately along the arrangement direction Y and can increase the light output brightness near the display area DA within the non-display area AA; the light output structure 124 increases the light output brightness near the light-incident surface 121 within the non-display area AA. Therefore, compared to conventional technology, the light guide plate 120 of this embodiment can effectively reduce the illuminance difference at distances of 1 mm and 2 mm from the light incident surface 121, thus effectively suppressing the occurrence of bright or dark fringes. Incidentally, in one embodiment, the contrast ratio of the light guide plate 120 at approximately 1 mm from the light incident surface 121 can be approximately 0.92, and the contrast ratio at approximately 2 mm from the light incident surface 121 can be approximately 0.87. In conventional technology, the contrast ratio of the light guide plate at 1 mm from the light incident surface is approximately 0.88, and the contrast ratio at 2 mm from the light incident surface is approximately 0.86, both of which are lower than the contrast ratio of the light guide plate 120. Therefore, the light guide plate 120 of this embodiment can effectively suppress the occurrence of bright and dark fringes.

[0046] Please refer to Figure 1 again. Incidentally, the backlight module 100 may also include a diaphragm assembly 130, and the light-emitting surface 122 of the light guide plate 120 faces the diaphragm assembly 130. Specifically, the diaphragm assembly 130 may include a diffuser and a prism.

[0047] The backlight module 100 may also include a reflective sheet 140, which may be disposed on the side of the light guide plate 120 opposite to the film assembly 130 to increase the light utilization rate of the backlight module 100. The material of the reflective sheet 140 may include silver.

[0048] FIG. 8 is a top view schematic diagram of a light guide plate of a backlight module according to another embodiment of the present invention. The structure and advantages of the backlight module 100e in this embodiment are similar to those of the embodiment in FIG. 1, and only the differences will be described below. It can be understood that the light guide columns 123 are not limited to being located within the non-display area AA. For example, referring to the light guide plate 120e shown in FIG. 8, the light guide columns 123e can be located within the non-display area AA and the display area DA. Thus, the light guide columns 123e can transmit more light beams to the side of the display area DA away from the light incident surface 121, thereby further improving the light utilization rate and also improving the light output uniformity and optical quality of the light guide plate 120e. Further, one side of the display area DA facing away from the light incident surface 121 has an edge E1, and the light guide column 123e can extend from the non-display area AA to the edge E1 of the display area DA to improve the light output uniformity and optical quality of the entire display area DA. Incidentally, because the light guide column 123e extends from the non-display area AA to the edge E1, the range of the length L1' of the light guide column 123e can be: L0 < L1' ≤ L.

[0049] FIG. 9 is a top view schematic diagram of a light guide plate of a backlight module according to another embodiment of the present invention. The structure and advantages of the backlight module 100f in this embodiment are similar to those of the embodiment in FIG. 1, and only the differences will be described below. Referring to FIG. 9, multiple light guide columns 123 are, for example, spaced apart from each other in the arrangement direction Y. The pitch between any two adjacent light guide columns 123 in the arrangement direction Y is P1', and W1 < P1' ≤ 5 * W1. Specifically, a part of the light output surface 122 is exposed from the groove 126f between two adjacent light guide columns 123, and the exposed light output surface 122 can be substantially flat. Therefore, the pitch P1' between any two adjacent light guide columns 123 can be within the above range to avoid the exposed area of the light output surface 122 being too large and affecting the light output luminance and uniformity of the light guide plate 120f. Similarly, the pitch P1' is the pitch between the first tops T1 of two adjacent light guide columns 123.

[0050] FIG. 10 is a cross-sectional schematic diagram of a display device according to an embodiment of the present invention. Referring to FIG. 10, the display device 200 includes a display panel 210 and a backlight module 100. The backlight module 100 and the display panel 210 are disposed opposite to each other. For example, the display panel 210 is disposed opposite to the light output surface 122 of the light guide plate 120. In this embodiment, the display panel 210 may include a liquid crystal display panel or other non-self-emitting display panels, but the present invention is not limited thereto.

[0051] Compared with the prior art, the display device 200 in this embodiment adopts the backlight module 100, so the image quality can be improved. In other embodiments, the display device 200 may adopt the backlight module 100e or 100f.

[0052] In summary, the backlight module and display device of the embodiments of the present invention have at least one of the following advantages. The backlight module of the present invention employs a light guide plate having a light guide post and a light emission structure. The light guide post guides the light beam from the light-emitting element to propagate generally along its extension direction, and a portion of the light beam is refracted from opposite sides of the light guide post in a direction generally parallel to the light incident surface during propagation, thereby improving the light mixing effect of the light beam on the light guide plate. On the other hand, the light emission structure guides the light beam from the light-emitting element to increase the local brightness on the light emission surface, thereby suppressing the generation of dark lines. Therefore, the backlight module of the present invention can effectively improve the light emission uniformity and optical quality of the light guide plate. The display device of the present invention employs the above-described backlight module, thus improving image quality.

[0053] The above description is merely a preferred embodiment of the present invention and should not be construed as limiting the scope of the invention. Any simple equivalent changes and modifications made in accordance with the claims and description of the invention are still within the scope of the patent. Furthermore, no embodiment or claim of the present invention needs to achieve all the objectives, advantages, or features disclosed in the invention. In addition, the abstract and headings are merely for assisting in patent document searches and are not intended to limit the scope of the invention. Furthermore, the terms "first," "second," etc., used in this specification or claims are only used to name elements or distinguish different embodiments or scopes, and are not intended to limit the upper or lower limit of the number of elements.

[0054] 100, 100e, 100f: Backlight module 110: Light-emitting element 111: Light-emitting unit 120, 120e, 120f: Light guide plate 121: Surface receiving light 122: Exposed surface 123, 123a, 123b, 123c, 123d, 123e: Light guide columns 124: Light-emitting structure 125:Plate body 126, 126f: Groove 130: Membrane assembly 140: Reflector 200: Display device 210: Display panel 1240: List the light structure 1241: The first list shows the light structure. 1242: The second list shows the light structure. A1, A2: Angle AA: Non-display area DA: Display area E: End E1, E2, E3: Edges GS1, GS2, GS1a, GS1b, GS1c, GS1d: Light guide surface H1, H2: Height L, L0, L1, L1', L2: Length N, Z: Normal direction OP1, OP2: Orthographic projection P1, P1', P2: Spacing S1, S2: Surface T1: First Top T2: Second Top W, W1, W2: Width X: Direction of extension Y: Arrangement direction

Claims

1. A backlight module, comprising: A light-emitting element; The light guide plate has an incident light surface, an exit light surface, multiple light guide pillars, and multiple exit light structures. The incident light surface faces the light-emitting element, and the exit light surface is connected to the incident light surface. The exit light surface has a non-display area and a display area. The non-display area is located between the incident light surface and the display area. Each of the light guide pillars protrudes from the exit light surface and is located within the non-display area, or is located in both the non-display area and the display area. The extension direction of each of the light guide pillars is parallel to a normal direction of the incident light surface, and the light guide pillars are arranged along an arrangement direction parallel to the incident light surface. A groove is formed between any two adjacent light guide pillars. The length of the light guide plate in the normal direction of the incident light surface is L, and the lengths of the light guide pillars in the normal direction of the incident light surface are L1, 1 mm ≦ L1 ≦ L. Each of the light-emitting structures protrudes from the light-emitting surface and is located within the non-display area, wherein the light-emitting structures are located on the trenches, and the orthographic projection of the light-emitting structures onto the light-emitting surface at least partially overlaps with the orthographic projection of the light guide pillars onto the light-emitting surface.

2. The backlight module as described in claim 1, wherein each of the light guide pillars further has a light guide surface, each of the light guide surfaces is connected to the light emitting surface, and an angle A1 is formed between each of the light guide surfaces and the light emitting surface, wherein 20°≦A1≦75°.

3. The backlight module as claimed in claim 1, wherein each of the light-emitting structures further has a surface connected to the light-emitting surface, and an angle A2 is formed between each of the surfaces and the light-emitting surface, 20°≦A2≦75°.

4. The backlight module as claimed in claim 1, wherein each of the light guide pillars further has a first top, and the first top is opposite to the light emitting surface, and the height of each of the light guide pillars between each of the first top and the light emitting surface is H1, 2 µm ≤ H1 ≤ 40 µm.

5. The backlight module as claimed in claim 1, wherein each of the light-emitting structures further has a second top, and the second top faces away from the light-emitting surface, and the height of each of the light-emitting structures between the second top and the light-emitting surface is H2, 2 µm ≤ H2 ≤ 40 µm.

6. The backlight module as described in claim 1, wherein the width of each of the light guide pillars in the arrangement direction is W1, 10 µm ≤ W1 ≤ 150 µm.

7. The backlight module as described in claim 1, wherein the width of each of the light-emitting structures in the normal direction of the light-incident surface is W2, 10 µm ≤ W2 ≤ 150 µm.

8. The backlight module as claimed in claim 1, wherein the light guide pillars and the light-emitting structures each have a light guide surface protruding from the light-emitting surface, and the light guide surface of each of the light guide pillars and the light-emitting structures includes at least one of curved surface and planar surface.

9. The backlight module as claimed in claim 1, wherein the light-emitting element comprises a plurality of light-emitting units, and each of the light-emitting units is located between any two adjacent light guide pillars in their extension directions.

10. A backlight module, comprising: A light-emitting element; The light guide plate has a light-incident surface, a light-exit surface, a plurality of light guide pillars, and a plurality of light-exiting structures. The light-incident surface faces the light-emitting element, and the light-exit surface is connected to the light-incident surface. Each of the light guide pillars protrudes from the light-exit surface, and the extension direction of each of the light guide pillars is parallel to a normal direction of the light-incident surface. The light guide pillars are arranged along an arrangement direction parallel to the light-incident surface. Each of the light-exiting structures protrudes from the light-exit surface and is located between any two adjacent light guide pillars. The light guide pillars are connected to each other in the arrangement direction.

11. A backlight module, comprising: A light-emitting element; The light guide plate has an incident light surface, an emitting light surface, multiple light guide pillars, and multiple emitting light structures. The incident light surface faces the light-emitting element, and the emitting light surface is connected to the incident light surface. Each of the light guide pillars protrudes from the emitting light surface, and the extension direction of each of the light guide pillars is parallel to a normal direction of the incident light surface. The light guide pillars are arranged along an arrangement direction parallel to the incident light surface. Each of the emitting light structures protrudes from the emitting light surface and is located between any two adjacent light guide pillars. The light guide pillars are spaced apart from each other in the arrangement direction, and a groove is formed between any two adjacent light guide pillars. The emitting light structures are located on the grooves, and the width of each of the light guide pillars in the arrangement direction is W1, the spacing between any two adjacent light guide pillars in the arrangement direction is P1, and W1≦P1≦5*W1.

12. A backlight module, comprising: A light-emitting element; The light guide plate has a light-incident surface, a light-exit surface, a plurality of light guide pillars, and a plurality of light-exiting structures. The light-incident surface faces the light-emitting element, and the light-exit surface is connected to the light-incident surface. Each of the light guide pillars protrudes from the light-exit surface, and the extension direction of each of the light guide pillars is parallel to a normal direction of the light-incident surface. The light guide pillars are arranged along an arrangement direction parallel to the light-incident surface. Each of the light-exiting structures protrudes from the light-exit surface and is located between any two adjacent light guide pillars. Each of the light guide pillars further has a first top, and the first top faces away from the light-exit surface. Each of the light-exiting structures further has a second top, and the second top faces away from the light-exit surface. The second top is offset from the first top in a normal direction of the light-exit surface.

13. A backlight module, comprising: A light-emitting element; The light guide plate has an incident light surface, an emitting light surface, multiple light guide pillars, and multiple emitting light structures. The incident light surface faces the light-emitting element, and the emitting light surface is connected to the incident light surface. Each of the light guide pillars protrudes from the emitting light surface, and the extension direction of each of the light guide pillars is parallel to a normal direction of the incident light surface. The light guide pillars are arranged along an arrangement direction parallel to the incident light surface. Each of the emitting light structures protrudes from the emitting light surface and is located between any two adjacent light guide pillars. The emitting light structures are arranged in a row along the arrangement direction, and the length of the row of emitting light structures in the arrangement direction is L2. The width of the light guide plate in the arrangement direction is W, where L2 = W.

14. A backlight module, comprising: A light-emitting element; The light guide plate has a light-incident surface, a light-exit surface, a plurality of light guide pillars, and a plurality of light-exiting structures. The light-incident surface faces the light-emitting element, and the light-exit surface is connected to the light-incident surface. Each of the light guide pillars protrudes from the light-exit surface, and the extension direction of each of the light guide pillars is parallel to a normal direction of the light-incident surface. The light guide pillars are arranged along an arrangement direction parallel to the light-incident surface. Each of the light-exiting structures protrudes from the light-exit surface and is located between any two adjacent light guide pillars. The light-exiting structures are arranged along the arrangement direction to form a first row of light-exiting structures and a second row of light-exiting structures, and the first row of light-exiting structures and the second row of light-exiting structures are spaced apart in the normal direction of the light-incident surface.

15. The backlight module as claimed in claim 14, wherein the width of each of the light-emitting structures in the normal direction of the light-incident surface is W2, and the spacing between the first row of light-emitting structures and the second row of light-emitting structures in the normal direction of the light-incident surface is P2, 2*W2≦P2.

16. A display device, comprising: A display panel; The display panel includes a backlight module disposed opposite to the display panel. The backlight module comprises: a light-emitting element; and a light guide plate having a light-incident surface, a light-emitting surface, multiple light guide pillars, and multiple light-emitting structures. The light-incident surface faces the light-emitting element, and the light-emitting surface is connected to the light-incident surface. The light-emitting surface has a non-display area and a display area, the non-display area being located between the light-incident surface and the display area. Each of the light guide pillars protrudes from the light-emitting surface and is located within the non-display area, or both the non-display area and the display area. The extension direction of each of the light guide pillars is parallel to a normal direction of the light-incident surface, and the light guide pillars are arranged along an arrangement direction parallel to the light-incident surface. A groove is formed between any two adjacent light guide pillars. The length of the light guide plate in the normal direction of the light-incident surface is L, and the lengths of the light guide pillars in the normal direction of the light-incident surface are L1, L2, L3, L4, L5, L6, L7, L8, L9, L10, L11, L12, L13, L14, L15, L16, L17, L18, L19, L1 ...1, L11, L11, L11, L11, L11, L11, L11 mm≦L1≦L; Each of the light-emitting structures protrudes from the light-emitting surface and is located within the non-display area, wherein the light-emitting structures are located on the grooves, and the orthographic projection of the light-emitting structures onto the light-emitting surface at least partially overlaps with the orthographic projection of the light guide pillars onto the light-emitting surface.

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