Backlight module having optical film on which multiple tapered structures are designed, and display device

Abstract

To provide a backlight module having an optical film on which multiple tapered structures are designed, and a display device.SOLUTION: A backlight module 100 comprises a light guide plate 130, a light source 190, and a first optical film 110. The light guide plate 130 has a light incident surface 131 and a light emergent surface 132 having a normal. The light sources 190 are arranged adjacent to the light incident surface 131. The first optical film 110 is disposed opposite the light emergent surface 132 and comprises parallel prisms 111 and multiple microstructures 112. The extension direction of each prism 111 is perpendicular to the normal, and each prism 111 faces the light emergent surface 132 of the light guide plate. Each microstructure 112 is located on a surface of the first optical film 110 facing away from the light guide plate 130. Each microstructure 112 is a tapered structure having multiple facets 112s. The multiple prisms 111 are located between the multiple microstructures 112 and the light emergent surface 132.SELECTED DRAWING: Figure 1B

Description

[Technical Field]

[0001] The present invention provides a backlight module and a display device in which a plurality of cone structures are designed in an optical film. The present invention relates to a display device, and more particularly to a side-illumination type backlight module and a display device including the same. do. [Background technology]

[0002] Conventional backlight modules usually have a diffusion sheet to make the light uniform. Generally, a typical diffusion sheet has a plurality of scattering particles, which scatter light rays. However, the scattering of light can be prevented by using a method that scatters light so that the light is uniform. The diffusion sheet having particles is usually used in concealers and In addition, it has low optical directivity and high It destroys the directivity. To improve the directivity, it is necessary to reduce the haze of the diffusion sheet. However, the concealer will be damaged. Prism sheets are advantageous for improving brightness, but The haze of the upper and lower diffusion sheets used in the backlight module affects brightness and optical It affects the appearance of the display and the brightness of the conventional backlight module. Therefore, it is difficult to further improve the concealing effect while maintaining the concealing effect. In addition, the ability to increase the light concentration at the viewing angle and the brightness at the front viewing angle can reduce backlash. This will be the focus of the design of the light module. Summary of the Invention

[0003] One embodiment of the present invention can improve the light concentration at the light viewing angle and the brightness at the front viewing angle. The present invention provides a backlight module including an optical film.

[0004] Another embodiment of the present invention provides a display device including the above backlight module.

[0005] A backlight module according to one embodiment of the present invention includes a light guide plate, a light source, and a first light source. The light guide plate has a light incident surface and a light exiting surface, and the light exiting surface has a normal. The first optical film is provided adjacent to the light-incident surface. The microstructure includes parallel prisms and multiple microstructures. The extension direction of each prism is perpendicular to the normal. Each prism faces the light output surface of the light guide plate. Each microstructure is located on the surface facing the backlight light guide plate of the backlight system. These prisms are located between these microstructures and the light output surface. Located.

[0006] In one embodiment of the present invention, the backlight module includes a plurality of second optical frames. These first optical films are in contact with these second optical films. These second optical films, located between the optical surface and the second optical film, include a plurality of prism sheets.

[0007] In one embodiment of the present invention, each prism sheet comprises a plurality of juxtaposed prism strips. The direction of extension of these prism strips of one prism sheet is different from the direction of extension of the other prism sheet. prism strips of the prism sheet.

[0008] In one embodiment of the present invention, the light exit surface is connected to one side of the light incident surface. A plurality of light emitting diodes are arranged in a line, and one of the prism sheets The extension direction of these prism strips is parallel to the straight line, and the extension direction of these prism strips of the other prism sheet is parallel to the straight line. The extension direction of the prism strip is perpendicular to the straight line.

[0009] In one embodiment of the present invention, the extension direction of these prisms is perpendicular to the straight line. .

[0010] In one embodiment of the present invention, the light exit surface is connected to one side of the light incident surface, and the light source is arranged in a straight line. The prism sheet has a plurality of light emitting diodes arranged in a line along the prism sheet. The direction of extension of the elastic strip is neither parallel nor perpendicular to the straight line.

[0011] In one embodiment of the present invention, the extension direction of these prisms is parallel to the straight line. .

[0012] In one embodiment of the present invention, these microstructures comprise a plurality of adjacent pyramids. It is a recessed hole.

[0013] In one embodiment of the present invention, these microstructures comprise a plurality of adjacent pyramids. It is a bump-shaped structure.

[0014] In one embodiment of the present invention, these microstructures are formed on one side of the first optical film. The electrodes are arranged in an array at an angle to the

[0015] In one embodiment of the present invention, the light guide plate is formed on a bottom surface opposite to the light output surface and a bottom surface opposite to the light output surface. Each light-guiding structure has a light-receiving surface and a non-light-receiving surface connected to each other. The light receiving surface faces the direction in which light from the light source travels, and a first included angle is formed between the light receiving surface and the bottom surface. The first and second included angles are formed between the non-light-receiving surface and the bottom surface. Both angles are acute, and the first included angle is smaller than the second included angle.

[0016] A display device according to another embodiment of the present invention includes the backlight module and the backlight A display panel is provided for the module.

[0017] Based on the above, these prisms and these microstructures allow the The light rays first pass through the prisms of the first optical film to improve the directionality. The microstructure of the first optical film then In this way, the first optical film maintains its concealer ability. Both can emit light in a concentrated manner, thereby improving the efficiency of the backlight module. Improves the light collection at the viewing angle of the emitted light and the brightness at the front viewing angle. [Brief explanation of the drawings]

[0018] For a more complete understanding of the embodiments and their advantages, reference is made to the following drawings, in which: . [Figure 1A] 1 is a schematic plan view of a backlight module according to an embodiment of the present invention; [Figure 1B] FIG. 1B is a schematic cross-sectional view taken along the line 1B-1B in FIG. 1A. [Figure 1C] FIG. 1C is a partial schematic plan view of the first optical film in FIG. 1B. [Figure 1D] FIG. 3 is a partial schematic plan view of a first optical film according to another embodiment of the present invention. [Figure 2A] FIG. 10 is a schematic plan view of a backlight module according to another embodiment of the present invention. [Figure 2B] 2B is a cross-sectional view taken along the line 2B-2B in FIG. 2A. [Figure 2C] FIG. 2C is a perspective schematic view of the backlight module of FIG. 2B. [Figure 2D] FIG. 2C is a schematic plan view of a part of the second optical film in FIG. 2B. [Figure 2E] FIG. 2C is a schematic plan view of a part of the second optical film in FIG. 2B. [Figure 3A] FIG. 10 is a schematic plan view of a plurality of prism sheets according to another embodiment of the present invention. [Figure 3B] FIG. 10 is a schematic plan view of a plurality of prism sheets according to another embodiment of the present invention. [Figure 4A] 1C is a spatial luminance distribution diagram of both the backlight module of the comparative example and the backlight module shown in FIG. 1B. [Figure 4B] 1C is a spatial luminance distribution diagram of both the backlight module of the comparative example and the backlight module shown in FIG. 1B. [Figure 5A] FIG. 10 is a spatial luminance distribution diagram of a backlight module of a comparative example. [Figure 5B] 3A and 3B are diagrams illustrating the spatial brightness distribution of backlight modules according to several embodiments of the present invention; [Figure 5C] 3A and 3B are diagrams illustrating the spatial brightness distribution of backlight modules according to several embodiments of the present invention; [Figure 5D] 3A and 3B are diagrams illustrating the spatial brightness distribution of backlight modules according to several embodiments of the present invention; [Figure 5E] 3A and 3B are diagrams illustrating the spatial brightness distribution of backlight modules according to several embodiments of the present invention; [Figure 6] FIG. 10 is a schematic cross-sectional view of a backlight module according to another embodiment of the present invention. [Figure 7] 1 is a schematic side view of a display device according to an embodiment of the present invention; DETAILED DESCRIPTION OF THE INVENTION

[0019] In the following description, in order to clarify the technical features of the present application, the elements in the drawings (for example, The dimensions (e.g., length, width, thickness, and depth) of layers, films, substrates, regions, etc. The amplifiers are amplified at different rates and the number of certain elements is reduced. The interpretation and number of elements in the drawings and the dimensions and shapes of the elements are not limited to the actual recipe. It should cover variations in size, shape and both due to pitch and / or tolerances. For example: The flat surfaces shown in the drawings may have roughness and / or non-linear features, and may be The corners of the elements shown in the drawings of this application may be rounded. It is not intended to accurately depict the actual shape of the element, and is not intended to be a representation of the actual shape of the element. It is not intended to limit the scope of protection of the claims.

[0020] Next, terms such as "about," "approximately," or "substantially" used in this application are clearly intended to be interpreted as meaning "approximately," ... or "substantially." The values and ranges described in the are not limited to those determined by the error that occurs during measurement. The range of allowable variations that can be understood by a person skilled in the art of the present invention is covered by the present invention. This error is due to limitations of both the measurement system and recipe conditions, for example. "About" means within one or more standard variations of the above numerical value, e.g., ±30%, ±20%, In this application, the terms "about," "approximately," or "approximately" can be used to express a range within ±10% or ±5%. The terms "substantially" and "substantially" mean that the optical properties, etching properties, mechanical properties, or other properties Depending on the situation, the acceptable variation range or standard variation can be selected, and a single standard All properties such as optical properties, etching properties, mechanical properties and other properties are It's not about covering up quality.

[0021] FIG. 1A is a schematic plan view of a backlight module according to one embodiment of the present invention; FIG. 1B is a schematic cross-sectional view taken along the line 1B-1B in FIG. 1A. 1B, the backlight module 100 includes a first optical film 110 1, the light guide plate 130 includes a light source 190. The light guide plate 130 has a light incident surface 131, a light exit surface 132, and a The light exit surface 132 has a normal N1 and may be connected to one side of the light incident surface 131. The light source 190 is disposed adjacent to the light incident surface 131 and emits a light beam L1 toward the light incident surface 131. The first optical film 110 is provided on the light output surface 132 and has a plurality of It includes a prism 111 and a plurality of microstructures 112 arranged side by side.

[0022] The extension direction E1 of each prism 111 is perpendicular to the normal N1, and each prism 111 is a guide. The first optical film 130 is a first optical film 132. ... 110, and each microstructure 112 is located on the surface facing away from the light guide plate 130. These prisms 111 are conical structures with slots 112s. 1A, the prism 111 is positioned between the light emitting surface 112 and the light emitting surface 132. For clarity, the microstructure 112 is omitted, and in FIG. 1A, the thick lines indicate two adjacent The thin lines represent the valleys between the prisms 111, and the thin lines represent the peaks of each prism 111.

[0023] As shown in FIG. 1B, the light guide plate 130 further has a bottom surface 133. The bottom surface 133 and the light output surface 132 are opposite to each other in the light guide plate 130. When the light source 190 emits a light ray L1 toward the light incident surface 131, the light ray L 1 enters the light guide plate 130 from the light incident surface 131, and a part of the light rays L1 enters the light guide plate 130 from the light incident surface 131. The light ray L1 is incident on the bottom surface 133. The bottom surface 133 can reflect a part of the light ray L1. For example, Surface 133 is a total internal reflection (TIR) surface. The light beam is constantly reflected within the light guide plate 130 and transmitted to the rear of the light guide plate 130. In addition, a part of the light beam L1 is totally reflected by the microstructure arranged on the bottom surface 133. The light is broken and the reflection angle is changed, and the light is separated from the light guide plate 130 through the light exit surface 132, and the first The light rays are incident on the prisms 111 of the optical film 110. By concentrating the emission of L1, the effect of increasing the directivity is achieved.

[0024] Then, the light ray L1 passes through the prism 111 into the first optical film 110 and enters the microphone. Maintaining the concealer away from the first optical film 110 via the structure 112 The concealer effect occurs when the microstructure 112 is arranged on the multiple facets 11 2s, and deflects the light beam L1 through a plurality of facets 112s to guide it in a plurality of output directions. This prevents too much of the light energy from being concentrated directly above the microstructure 112. This is to avoid the usual halftone dot microstructure or diffusion particles and maintain the concealer effect. This causes light rays to scatter in an indefinite direction, effectively controlling the direction of the concealer. I can't do that.

[0025] The light ray L1 passes through the light guide plate 130 and the first optical film 110 in order to be incident on the backlight module. Upon leaving module 100, prism 111 and microstructure 112 refract ray L1. The output angle of the light ray L1 from the first optical film 110 can be adjusted by adjusting the angle of the light ray L1. The first optical film 110 is not equal to the exit angle at the plate 130, and the light ray L1 is incident on the first optical film 110. The light can be deflected and emitted in the direction of the line N1, thereby forming a backlight. Improves the light concentration and brightness of the front viewing angle of the module.

[0026] The backlight module of the prior art includes, for example, two diffusion sheets, two prism sheets, and The light output viewing angle is 1 / 300 sq.m. compared to the direction perpendicular to the light output surface 132 of the light guide plate 130. The skew is about 60 degrees, and the directivity is poor. The angle is not limited, and the anti-peeping effect is low. When the optical film 110 is used, the directivity can be improved, and the overall output The light energy is relatively concentrated, and the light rays are more polarized in the direction perpendicular to the light output surface 132 of the light guide plate 130. The viewing angle of the light is approximately 40 to 50 degrees.

[0027] That is, such a first optical film 110 maintains high directivity and concealer properties. It has the characteristic of further improving the brightness at the front viewing angle and saving energy. This is in line with future trends that will increase range and brightness.

[0028] Furthermore, the light source 190 is a plurality of light-emitting diodes arranged along a straight line SL1. Specifically, these light emitting diodes 191 are arranged in a stripe. The light emitting diodes 191 may be mounted on a circuit board in the shape of a straight line. These light emitting diodes 191 may be arranged along a straight line SL1. The above circuit board may be integrated into a single light bar. The circuit board is a printed circuit board (PCB). or flexible printed circuit board (FP) As shown in FIG. 1A, the first optical film 110 may have the following structure: The extension direction E1 of the prism 111 may be parallel to the straight line SL1.

[0029] FIG. 1C is a partial schematic plan view of the first optical film shown in FIG. 1B. The first optical film 110 is depicted along the cross section of section line CR1 in FIG. 1C. 1B and 1C, these microstructures 112 are formed by a plurality of adjacent corners. The recess may be pyramidal, and the facets 112s may be side walls of the pyramidal recess. For example, each microstructure 112 may be a pyramidal recess, so that each microstructure The structure 112 may have four facets 112s (i.e., sidewalls), with opposing facets 112s. The included angle between the facets 112s may be about 90 degrees. 112 may be a regular pyramid symmetrical with respect to both the X-axis direction and the Y-axis direction. Asymmetric: Symmetric along either the axial or Y-axis, but asymmetric along the other axis The illuminating element may be a pyramid, which will deflect the light rays to different degrees in different directions. By using this, it is possible to effectively control the concealer effect in different directions. In the example, these microstructures 112 are a plurality of adjacent pyramidal bumps. The shape may be pyramidal, and the facets 112s may be pyramidal. The microstructure 112 may be a bump or a recess. 1B and 1C are merely examples and are not intended to limit the present invention. In FIG. 1C, these microstructures 112 are arranged along one side of the first optical film 110. In another embodiment shown in FIG. 1D, the These microstructures 112 of the first optical film 110' in the first optical film They may be arranged in an array diagonally with respect to one side of 110.

[0030] FIG. 2A is a schematic plan view of a backlight module according to another embodiment of the present invention; 2B is a schematic cross-sectional view taken along the line 2B-2B in FIG. 2A. 2B, the backlight module 200 of this embodiment is the same as the backlight module 200 of the previous embodiment. The backlight module 200 is similar to the backlight module 100. For example, the backlight module 200 is also It includes a first optical film 110, a light guide plate 130, and a light source 190. The differences between the backlight modules 100 and 200 will now be described. The explanations for the similar points of 200 and 100 will not be repeated.

[0031] In this embodiment, the light emitting diodes 191 in the light source 190 are also aligned along the straight line SL1. However, the backlight module 2 in the above embodiment is Unlike the optical film 110 shown in FIG. 2A, these prisms 11 1 extends along an extension direction E2, which is perpendicular to the straight line SL1. Since 1 is parallel to the straight line SL1, the extension direction E1 may be perpendicular to the extension direction E2.

[0032] FIG. 2C is a perspective schematic view of the backlight module of FIG. 2B. For reference, the backlight module 200 includes a plurality of second optical films 221 and a diffusion film. The first optical film 110 further includes a diffusion sheet 222, and the second optical film 110 These second optical frames are located between the frame 221, the diffusion sheet 222, and the light output surface 132. The film 221 may include multiple prism sheets. In the embodiment shown in FIG. The second optical film 221 is a prism sheet. is located between the diffusion sheet 222 and the first optical film 110. The optical film 221, the diffusion sheet 222, and the microstructure 112 are not shown. , the extension direction E2 of these prisms 111 of the first optical film 110 is clearly shown.

[0033] 2D and 2E show the prism sheets (i.e., the second optical filter) in FIG. 2B. 2D is a schematic plan view of the second optical film 221 shown in FIG. 2B. 2E. The film 221 is the second optical film 221 located at the top in FIG. 2B. 2E, each second optical film 221 (i.e., prism sheet) has a plurality of 2D and 2E, the thick lines indicate adjacent prism strips 221s. The thin lines represent the valleys between two prism strips 221s. Represents the mountain of 1s.

[0034] The extension of these prism strips 221s of one of the second optical films 221 The direction of the prism strips 221s of the second optical film 221 is These second optical films 221 are perpendicular to the extending direction of the light beam L1. The light can be guided to exit along the direction of the row normal N1. In the example, the prism strips 221s of the upper second optical film 221 extend in the direction E2 (as shown in FIG. 2D) to remove the prismatic pattern of the lower second optical film 221. Since the strip 221s extends along the extending direction E1 (as shown in FIG. 2E), The extending direction E2 of the prism strips 221s of the second optical film 221 is The direction is perpendicular to the extending direction E1 of the prism strips 221s of the second optical film 221.

[0035] Since the extension direction E1 is parallel to the straight line SL1 and the extension direction E2 is perpendicular to the straight line SL1, The extending direction E1 of the prism strips 221s of the lower second optical film 221 is a straight line. SL1 and the prism strips 221s of the upper second optical film 221. The extending direction E2 is perpendicular to the straight line SL1. These prism strips 221 of the sheet (e.g., the lower second optical film 221) The extension direction E1 of the s is parallel to the straight line SL1, and the other prism sheet (for example, the upper The extension direction E2 of these prism strips 221s of the second optical film 221 is: It is perpendicular to the line SL1.

[0036] In particular, in the embodiment shown in FIGS. 2D and 2E, two second optical films 221 are The extending directions E1 and E2 of the elastic strip 221s are parallel and perpendicular to the straight line SL1, respectively. However, in other embodiments, each of these second optical films 221 The extending direction of these prism strips 221s can be parallel or perpendicular to the straight line SL1. But not.

[0037] 3A and 3B, the second optical film 321a and the second optical film 321b shown in FIG. and 321b are the same as the second optical film 221, and each is a plurality of parallel The difference is that the second optical film 321a and 321b include a row of prism strips 221s. The extending direction of both prism strips 221s of the second optical film 221 is different from that of the second optical film 221. The only point is that

[0038] Specifically, the second optical films 321a and 321b shown in FIGS. 3A and 3B are 2B. For example, in FIG. 3A, The second optical film 321a shown in FIG. 2B is the upper second optical film 221. 3B may be replaced by the second optical film 321b shown in FIG. 2B. The optical film 221 may be replaced with the optical film 221.

[0039] According to the above configuration, the high directivity and The arrangement of the light emitting diodes 191 of the light source 190 has the effect of maintaining the concealer. The column direction and the extension direction of these prisms 111 in the first optical film 110 are parallel to each other. These prism strips are designed to correspond to the prism sheets. The extension direction of the light emitting diodes 191 of the light source 190 is neither parallel nor perpendicular to the arrangement direction of the light emitting diodes 191. In each of these second optical films 221 as shown in FIGS. 3A and 3B The extension directions of these prism strips 221s are all along a straight line SL1 (FIGS. 3A and 3B). 3B)). For example, the second The optical film 221 is stretched along the extension direction E31, and the second optical film 221 shown in FIG. 221 extends along the extension direction E32, and both the extension directions E31 and E32 are the same as the extension direction E The extension directions E31 and E32 are neither parallel nor perpendicular to the direction E1, and are perpendicular to each other.

[0040] For example, the angle A31 between the extension directions E31 and E1 in FIG. 3A is about 45 degrees. The angle A31 between the extending direction E32 and E1 in FIG. 3B is about 135 degrees. In this way, the extending directions E31 and E32 may be either parallel or perpendicular to the extending direction E1. Not only that, the angle between the extension directions E31 and E32 may be about 90 degrees, i.e. That is, both of the extending directions E31 and E32 are perpendicular to each other. The direction of the light can be adjusted perpendicular to the light output surface 132 of the light guide plate 130, and the light output viewing angle can be adjusted to approximately 0 degrees, the brightness can be further improved, and the full width at half maximum (FWHM) of the emitted light energy is FWHM) This contributes to improving the effectiveness of preventing peeping.

[0041] The second optical film 221 and the diffusion sheet 222 shown in FIG. 2B are This can also be applied to the backlight module 100 in the above embodiment. In other words, the backlight module 100 in FIG. 1B is a second The optical film 221 and the diffusion sheet 222 may be further included. The first optical film 110 can be replaced with the first optical film 110 in FIG. 1B. Therefore, both the backlight modules 100 and 200 can The optical film 221 and the diffusion sheet 222 may be included.

[0042] 4A and 4B are diagrams illustrating the backlight module of the comparative example and the backlight module shown in FIG. 1B, respectively. 4A and 4B are spatial luminance distribution diagrams of both the light module and the light module. 4B and 5A to 5E) are essentially color maps. The fabric map is displayed as a grayscale image, with the lighter grayscale representing the representative In other words, in the spatial luminance distribution diagram of the present application, In this case, the lighter the gradation, the higher the representative brightness. Conversely, the darker the gradation, the lower the representative brightness. The spatial luminance distribution diagrams shown in FIGS. 4A, 4B, and 5A to 5E are all calculated by computer. FIG.

[0043] 4A and 4B, FIG. 4A shows a backlight module of a comparative example. The light source, the light guide plate, and the conventional diffusion sheet containing scattering particles, but also any prism sheet FIG. 4B shows the backlight module 100 shown in FIG. 1B. The backlight module 100 does not include the second optical film 221. The light source and the light guide plate included in the example backlight module are respectively as shown in FIG. 1B. In addition, the light source 190 and the light guide plate 130 may be the same.

[0044] 4A and 4B, FIGS. 4A and 4B show a backlight module of a comparative example and a The backlight module 100 is observed from above to simulate the luminance distribution. In Fig. 4A and Fig. 4B, the vertical and horizontal axes represent angles. The center where both horizontal axes intersect is the light output surface of the light guide plate (for example, the light output surface 132 of the light guide plate 130). The central axis can be represented.

[0045] 1A, 1B, and 4B, taking the backlight module 100 as an example, The center where the vertical axis and the horizontal axis in FIG. 4B intersect is the central axis OB of the light-emitting surface 132 in FIG. 1A. 4B is equal to the observation angle SA1 shown in FIG. 1B. Degrees SA1 is the angle between the central axis OB1 and the observation direction OD1, and the absolute value of the observation angle SA1 is between 0 and 90 degrees. When the vertical axis angle in FIG. 4B is zero, the observation direction O The angle between D1 and the central axis OB1 is zero, i.e., a zero vertical axis angle is This represents observing the brightness of the backlight module 100 from axis OB1.

[0046] When the angle of the vertical axis in FIG. 4B is a negative value, the observation direction OD1 is The angle of the vertical axis of the light exit surface 132 is biased toward the light entrance surface 131. That is, the angle of the vertical axis of the light exit surface 132 is biased toward the light entrance surface 131. This means observing the brightness of the backlight module 100 from the adjacent side. When the angle of the vertical axis in FIG. 4B is a positive value, the observation direction OD1 is The angle of the vertical axis that is off the surface 131, i.e., a positive value, is the angle of the vertical axis that is away from the light entrance surface 131 by the light exit surface 132. The luminance of the backlight module 100 is observed from a distance and measured at an observation angle SA shown in FIG. 1B. Similarly, the luminance change on the horizontal axis in FIG. 4B represents the change in the backlight module in FIG. 1A. 1 represents the luminance distribution between the left and right sides of module 100.

[0047] The viewing angle of the comparative backlight module shown in FIG. 4A is about 61 degrees, and FIG. The viewing angle of the backlight module 100 shown in FIG. 1 is about 40 degrees, of which the viewing angle refers to the peak angle of the light beam. Most of the area in Figure 4A has a fairly shallow grayscale. However, most of the area in Figure 4B has a fairly dark grayscale, with one small blip in particular. Only the light grayscale and the darkest grayscale are displayed on the lock. In this way, the first optical film 110 prevents the backlight module from It was found that the light directivity of the backlight module 100 was higher than that of the backlight module of the comparative example. Light.

[0048] Furthermore, the half-width of brightness (F Full Width at Half Maximum (FWHM) is approximately 69 degrees, The brightness half-width on the horizontal axis is about 40 degrees. The brightness half width on the vertical axis is about 40 degrees, and the brightness half width on the horizontal axis is about 10 degrees. The half-width of the backlight module 100 in B is the same as that of the comparative example in FIG. 4A. Since the half-width of the backlight module is smaller than that of the backlight module 10 in FIG. The light directivity of the backlight module of FIG. 4A is higher than that of the backlight module of the comparative example. , that is, the backlight module 100 shown in FIG. 4B emits light in a concentrated manner. It is possible.

[0049] FIG. 5A is a spatial luminance distribution diagram of the backlight module of the comparative example, and FIGS. 5B to 5 5A to 5E are spatial luminance distribution diagrams of backlight modules according to several embodiments of the present invention. Therefore, the definitions of the vertical and horizontal axes in FIG. 5E are the same as those in FIGS. 4A and 4B. The meaning is the same as above, and the explanation will not be repeated here.

[0050] Referring to FIGS. 5A and 5B, the backlight module of the comparative example shown in FIG. , including a light guide plate and a diffusion sheet, as well as two prism sheets, 5B does not include the first optical film 110. FIG. 5B shows the first optical film 110 and the two prism sheets. a backlight unit to which a diffusion sheet 222 is added (i.e., a second optical film 221) and a diffusion sheet 222 are added; 2B and 2C show the light module 100, and the two prism sheets are respectively installed as shown in FIG. 2D and 2E, i.e., the extension of the prism strips of one prism sheet. The direction is the extension direction of the prisms 111 of the first optical film 110 (all extension direction E1). , and the extension direction of the prism strips of the other prism sheet is parallel to the prism 111 (extension directions E1 and E2, respectively).

[0051] These prism sheets (for example, the second optical film 221) are The majority of the light rays of the module are emitted along the normal (e.g., normal N1 in Figure 1B). Therefore, the backlight in both Figs. The viewing angle of the modules is approximately 0 degrees. Next, the backlight of the comparative example shown in FIG. 5A The brightness half-width on the vertical axis of the module is approximately 45 degrees from the brightness half-width on the horizontal axis. The brightness half-width on the vertical axis of the backlight module in B is about 38 degrees, and The brightness half-width at this angle is approximately 31 degrees. The module emits light in a concentrated manner and is more efficient than the comparative backlight module in FIG. 5A. This architecture has a high light directivity and can improve brightness by approximately 15%. In the device, the microstructure 112 shown in FIG. 1D is used to form a first optical film 110 on one side. 2A. The first optical filter 111 shown in FIG. 1A extends along the extending direction E2. 110 extend along the direction of extension E1. The WHM energy can be more concentrated, resulting in greater brightness.

[0052] FIG. 5C shows the spatial luminance of the backlight module according to another embodiment of the present invention shown in FIGS. 3A and 3B. Referring to FIG. 5C, FIG. 5C shows the first optical film 110, the two plates After the rhythm sheet (i.e., the second optical film 221) and the diffusion sheet 222 are attached, 5C shows a backlight module 100. However, unlike FIG. 5B, the In the backlight module, the installation of these two prism sheets is as follows: As shown in FIGS. 3A and 3B, the prism strips of these two prism sheets The extending directions of the prisms are parallel to the extending direction E1 of the prisms 111 of the first optical film 110. As shown in Figures 3A and 3B, the prism strips of one prism sheet are aligned vertically and horizontally. The lip is oriented at 45 degrees, and the prism strips on the other prism sheet are oriented at 13 degrees. It is 5 degrees.

[0053] In the embodiment shown in FIG. 5C, these prism sheets (e.g., second optical films) 221) is arranged so that the light rays exit along the normal (e.g., normal N1 in FIG. 1B). Therefore, the viewing angle of the backlight module in FIG. 5C is approximately 0 degrees. Next, the brightness half-width on the vertical axis of the backlight module in FIG. 5C is about 34 The brightness half-width on the horizontal axis is approximately 30 degrees. Compared with the backlight module, the backlight module in FIG. It emits concentrated light, has good light directionality, and can improve brightness by about 20%.

[0054] 5D and 5E are diagrams illustrating the spatial brightness distribution of a backlight module according to another embodiment of the present invention. 5D and 5E are diagrams of the backlight module shown in FIGS. 2A and 2B. The prisms 111 of the first optical film 110 extend in the direction E2. However, the backlight module 200 shown in FIG. The first optical film 110 is added, but the second optical film 221 and the diffusion sheet 2 5E shows the complete backlight module 200, without the prism 22. The orientation of the prism strips of one sheet is 0 degrees, and the orientation of the prism strips of the other prism sheet is 0 degrees. The lip direction is 90 degrees, as shown in Figure 2A. The viewing angle of the module 200 is about 52 degrees, and the brightness half-width on the vertical axis is about 24 degrees. The brightness half-width on the horizontal axis is about 20 degrees. Compared to the module, the prism sheet (i.e., the second optical film 221) and the diffusion sheet In the absence of 222, the backlight module 200 shown in FIG. 5D has excellent It has light directionality and can generate a spectral effect, and has a wide viewing angle on both the left and right sides (light areas on both sides). This allows for sufficient brightness in the dark and light areas (white areas).

[0055] In FIG. 5E, these second optical films 221 (i.e., prism sheets) By guiding the light beam, the backlight module 200 (the second optical film 221 and the diffusion The viewing angle of the backlight module (including the sheet 222) is approximately 0 degrees. The brightness half width on the vertical axis of the rule 200 is about 34 degrees, and the brightness half width on the horizontal axis is about 2 7 degrees. Compared with the comparative example in FIG. 5A, the backlight module in FIG. 5E 200 has good light directivity and originally the spectral effect in Figure 5D is Concentrate on the dark and white areas in the color and light areas, and improve brightness by approximately 20%. It is possible.

[0056] 6 is a schematic cross-sectional view of a backlight module according to another embodiment of the present invention. Referring to FIG. 1, the backlight module 600 of this embodiment is the same as the backlight module 600 of the previous embodiment. Similar to module 100, the difference between backlight module 600 and 100 is the The light guide plate 630 included in the backlight module 600 is the same as the light guide plate 130 in the previous embodiment. The following mainly focuses on the differences between the backlight modules 600 and 100. However, the same features of both will not be described again.

[0057] Specifically, the light guide plate 630 has a bottom surface 633 and a plurality of light guide structures formed on the bottom surface 633. 639, where each light-guiding structure 639 has a light-receiving surface 639a and a non- The light receiving surface 639a faces the traveling direction of the light beam L1 of the light source 190. As shown in FIG. 6, a first included angle A61 is formed between the light receiving surface 639a and the bottom surface 633. The non-light-receiving surface 639b forms a second included angle A62 with the bottom surface 633, and the first included angle A61 and the second included angle A62 form a second included angle A62 with the non-light-receiving surface 639b. The angles A62 are all acute angles, and the first included angle A61 is smaller than the second included angle A62.

[0058] When the light source 190 emits a light ray L1 toward the light incident surface 631 of the light guide plate 630, the light ray L1 A light beam L1 enters the light guide plate 630 from the light surface 631 and enters the light guide structure 639. The light ray L1 is incident on the light receiving surface 639a. 639a), and the light ray L1 is emitted from the light exit surface 632 of the light guide plate 630. This design allows the area of the light-receiving surface 639a to be enlarged and the area of the non-light-receiving surface 639b to be reduced. Therefore, the light receiving surface 639a can reflect the light beam with a higher probability and guide the light beam to the light guide plate 630. The light is emitted from the light exit surface 632, thereby providing a directional light source for the first optical film 110. It contributes to improving sexuality.

[0059] The backlight module 600 further includes a light-reflecting sheet 680. 80 is located below the light guide plate 630 and faces the bottom surface 633. The light guide plate 630 has a light reflecting sheet. The light ray L1 enters the light-guiding structure 639. 6, the light-guiding structure 639 not only reflects the light ray L1 but also guides the light ray L When the light-guiding structure 639 refracts the light ray L1, the light ray L1 is reflected by the light. The light ray L1 is incident on the light reflecting sheet 680. The light reflecting sheet 680 reflects the light ray L1 and and can enter the light guide plate 630, so that more light rays L1 can be In this way, the brightness of the backlight module 600 can be increased. Contribute to the improvement of

[0060] The backlight module 600 in FIG. 6 includes a plurality of second optical films 22 1 and a diffusion sheet 222 (shown in FIG. 2B), or a plurality of second optical films 321a and 321b (shown in FIGS. 3A and 3B). In the light module 200, the light guide plate 130 is replaced with a light guide plate 630 shown in FIG. The first optical film 110 in FIG. 6 may be the same as the first optical film 110 in FIG. 6, the first optical film 110 may be replaced by the second optical film 110. These prisms 111 of 110 may extend along an extension direction E1 or E2.

[0061] FIG. 7 is a schematic side view of a display device according to an embodiment of the present invention. The display device 700 includes a backlight module 710 and a display panel 720, The display panel 720 is provided with respect to the backlight module 710. By being positioned above the light emitting surface of the backlight module 710, A light beam can be emitted towards the display panel 720 .

[0062] The backlight module 710 is the same as the backlight module 100 in the previous embodiment. , 200 or 600, or any of these backlight modules 100, 200 and 600 Any combination, for example, a plurality of second optical films 221 and a diffusion sheet 222 may be used. It may be the backlight module 100. Therefore, the backlight module 710 The display panel 720 includes a first optical film 110. The display panel 720 is, for example, a liquid crystal display panel. The first optical film 110 may be a concealer. By concentrating the light beam L1, the backlight module The light directionality of the backlight module 710 can be improved, so that the backlight module 710 has high brightness. It can emit light rays of 90 degrees uniformly, improving the light concentration at the viewing angle and the brightness at the front viewing angle. At the same time, it has a concealer effect, improving the brightness and uniformity of the display panel 720.

[0063] Although the embodiments of the present invention have been disclosed above, they are not intended to limit the present invention. Those skilled in the art to which the present invention pertains will recognize that the present invention is not limited to the above-described embodiments, and that the present invention is not limited to the above-described embodiments. , and slight changes and modifications can be made, so the scope of protection of the present invention is as defined in the accompanying claims. The scope of protection is limited by the scope. [Explanation of symbols]

[0064] 100, 200, 600, 710 Backlight Module 110, 110' First optical film 111 Prism 112 Microstructure 112s Facet 130, 630 light guide plate 131, 631 Light entrance surface 132, 632 light emission surface 133, 633 bottom 190 Light source 191 Light-emitting diode 221, 321a, 321b Second optical film 221s Prism Strip 222 Diffusion Sheet 639 Light guide structure 639a Photosensitive surface 639b Non-light receiving surface 680 Light Reflective Sheet 700 Display device 720 display panel A31 Enclosing angle A61 First included angle A62 Second included angle CR1 cross section line E1, E2, E31, E32 Extending direction L1 ray N1 normal OB1 center axis OD1 Observation direction SA1 Observation Angle SL1 Straight Line

Claims

1. A backlight module in which a plurality of cone structures are designed on an optical film, a light guide plate having a light entrance surface and a light exit surface having a normal; a light source disposed adjacent to the light entrance surface; a first optical film provided on the light output surface, the first optical film includes a plurality of juxtaposed prisms and a plurality of microstructures; The extension direction of each of the prisms is perpendicular to the normal line, and each of the prisms is located on the light guide plate Facing the light output surface of Each of the microstructures is located on a surface of the first optical film facing away from the light guide plate. Each of the microstructures is a pyramidal structure having a plurality of facets, and a plurality of the prisms a microstructure disposed between the plurality of microstructures and the light output surface; A backlight module with multiple cone structures designed into the optical film.

2. The optical film further includes a plurality of second optical films, and the first optical film is and the light output surface, and the plurality of second optical films are Including prism sheet, A backlight module, in which a plurality of cone structures are designed on the optical film according to claim 1.

3. Each of the prism sheets includes a plurality of prism strips arranged side by side, and the prisms The extension direction of the plurality of prism strips of one sheet is the same as the extension direction of the plurality of prism strips of another prism sheet. perpendicular to the extension direction of the prism strips; A backlight module, in which a plurality of cone structures are designed on the optical film according to claim 2.

4. The light exit surface is connected to one side of the light incident surface, and the light sources are arranged in a straight line. a plurality of light emitting diodes arranged on the prism strips of the prism sheet; The extending direction of the prism sheets is parallel to the straight line, and the extending direction of the prism sheets of the other prism sheets is parallel to the straight line. The extension direction of the trip is perpendicular to the straight line. A backlight module, in which a plurality of cone structures are designed on the optical film according to claim 3.

5. The extension direction of the prism is perpendicular to the straight line. A backlight module, in which a plurality of cone structures are designed on the optical film according to claim 4.

6. The light exit surface is connected to one side of the light incident surface, and the light sources are arranged in a straight line. a plurality of light emitting diodes arranged in the prism strips of each of the prism sheets; The extension direction of the tape is neither parallel nor perpendicular to the straight line. A backlight module, in which a plurality of cone structures are designed on the optical film according to claim 3.

7. The extension direction of the prism is parallel to the straight line. A backlight module, in which a plurality of cone structures are designed on the optical film according to claim 6.

8. The plurality of microstructures are a plurality of pyramidal recesses adjacent to each other. The optical film according to any one of claims 1 to 7, further comprising a backing having a plurality of cone structures designed thereon. Crite module.

9. The plurality of microstructures are a plurality of pyramidal bumps adjacent to each other. The optical film according to any one of claims 1 to 7, further comprising a backing having a plurality of cone structures designed thereon. Crite module.

10. The plurality of microstructures are arranged in an array obliquely with respect to one side of the first optical film. are arranged, The optical film according to any one of claims 1 to 7, further comprising a backing having a plurality of cone structures designed thereon. Crite module.

11. The light guide plate has a bottom surface facing the light output surface and a plurality of light guide structures formed on the bottom surface. Each of the light-guiding structures has a light-receiving surface and a non-light-receiving surface connected to each other, and the light-receiving surface is The light receiving surface faces the light traveling direction of the light source, and forms a first included angle with the bottom surface. The light receiving surface forms a second included angle with the bottom surface, and the first included angle and the second included angle are both an acute angle, and the first included angle is smaller than the second included angle; The optical film according to any one of claims 1 to 7, further comprising a backing having a plurality of cone structures designed thereon. Crite module.

12. A display device, The optical film according to any one of claims 1 to 11, further comprising a plurality of cone structures. Backlight module and a display panel disposed relative to the backlight module; Display device.

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