Backlight module and display device
By combining a reverse prism, a first prism, and a second prism, the problem of limited viewing angle in LCD displays is solved. This achieves increased brightness and viewing angle without increasing energy consumption, thereby improving energy efficiency and product lifespan.
Patent Information
- Application Number
- CN202423016393.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-06
- Publication Date
- 2025-10-21
- Estimated Expiration
- 2034-12-06
AI Technical Summary
Existing LCDs have limited viewing angles, and increasing brightness to expand viewing angles often results in wasted energy and shortened product lifespan.
A combination structure of an inverse prism, a first prism, and a second prism is used to guide light through a light guide plate to emit at a large angle, increasing the brightness of light at vertical and horizontal viewing angles. The bottom angle of the second prism column is between 51 and 61 degrees.
Without increasing the power consumption of light-emitting components, the brightness and viewing angle of light with a wide viewing angle are effectively increased, thus improving energy waste and product life.
Smart Images
Figure CN223461768U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model relates to a light source module, in particular to a backlight module and a display device with the backlight module. BACKGROUND
[0002] The components of a liquid crystal display mainly include a backlight module, a display panel and a frame. According to the direction of the light source, the backlight module can be divided into a side light type backlight module and a direct type backlight module. The direct type backlight module has the advantage of better uniformity of the surface light source, and the side light type backlight module has the advantages of low energy consumption and low cost. Therefore, the side light type backlight module and the direct type backlight module have different market orientations.
[0003] Generally speaking, no matter whether it is a side light type backlight module or a direct type backlight module, the light brightness of the liquid crystal display is mostly the largest at the normal viewing angle, and becomes lower as the viewing angle deviates from the normal viewing angle, resulting in limited viewing angle of the liquid crystal display. Therefore, if the viewing angle of the liquid crystal display is to be improved, the brightness of the side viewing angle can only be increased by increasing the power consumption of the backlight module in the known technology, thus causing energy waste and reduction of product life and other disadvantages.
[0004] The background section is used to help understand the content of the utility model, so the content disclosed in the background section may include some known technology that does not constitute the known technology known to those skilled in the art. The content disclosed in the background section does not represent the problems to be solved by the content or one or more embodiments of the utility model, which have been known or recognized by those skilled in the art before the utility model application. CONTENT OF THE UTILITY MODEL
[0005] The utility model provides a backlight module to increase the light brightness of large viewing angle and improve the problems of energy waste and reduction of product life.
[0006] The utility model provides a display device to increase the viewing angle and improve the problems of energy waste and reduction of product life.
[0007] Other purposes and advantages of the utility model can be further understood from the technical features disclosed in the utility model.
[0008] To achieve one or part or all of the above purposes or other purposes, an embodiment of the present utility model provides a backlight module, including light emitting element, light guide plate, inverse prism sheet, first prism sheet and second prism sheet. The light guide plate has the light entrance surface and the light exit surface which are connected, and the light entrance surface is opposite to the light emitting element. The inverse prism sheet is arranged on the light exit surface of the light guide plate. The inverse prism sheet has a plate body and a plurality of prism columns. The prism column is arranged on the side of the plate body facing the light exit surface, and the prism column extends towards a direction. The first prism sheet is arranged on the side of the inverse prism sheet opposite to the light guide plate, and the first prism sheet has a first plate body and a plurality of first prism columns. The first prism column is arranged on the side of the first plate body opposite to the inverse prism sheet, and the first prism column extends towards the first direction. The angle between the direction and the first direction is between 85-95 degrees. The second prism sheet is arranged on the side of the first prism sheet opposite to the inverse prism sheet, and the second prism sheet has a second plate body and a plurality of second prism columns. The second prism column is arranged on the side of the second plate body opposite to the first prism sheet, and the second prism column extends towards the second direction. The angle between the first direction and the second direction is between 85-95 degrees. Each second prism column has two base angles, the two base angles connect the surface of the second plate body, and the angle of each two base angles is between 51-61 degrees.
[0009] To achieve one or part or all of the above purposes or other purposes, an embodiment of the present utility model provides a display device, including the backlight module and the display panel. The display panel is arranged on the side of the second prism sheet opposite to the first prism sheet.
[0010] The backlight module of the present utility model sequentially arranges the inverse prism sheet, the first prism sheet and the second prism sheet on the light guide plate, wherein the inverse prism sheet can guide the light to be incident on the first prism sheet in a substantially normal direction, and the first prism sheet and the second prism sheet respectively guide the light to be emitted at a large angle, thereby respectively increasing the light emission brightness of a large viewing angle in the vertical viewing angle and the horizontal viewing angle. In addition, the angle of the base angle of the second prism column is between 51-61 degrees, so that the light can be guided to be emitted at a larger angle, thereby further increasing the viewing angle of the backlight module in the horizontal viewing angle. Therefore, the backlight module of the present utility model can effectively increase the light emission brightness of a large viewing angle without increasing the power consumption of the light emitting element, and can improve the problems of energy waste and product life reduction. The display device of the present utility model adopts the above-mentioned backlight module, so that the viewing angle can be effectively increased, and the problems of energy waste and product life reduction can also be improved.
[0011] In order to make the above and other purposes, features and advantages of the present utility model more obvious and easy to understand, the following embodiments are specifically described below, and the drawings are as follows. BRIEF DESCRIPTION OF DRAWINGS
[0012] Figure 1 It is a schematic diagram of the backlight module of an embodiment of the present utility model.
[0013] Figure 2is Figure 1 A partial enlarged side view schematic of the second prism sheet of the backlight module.
[0014] Figure 3 is Figure 1 A partial enlarged side view schematic of the inverse prism sheet of the backlight module.
[0015] Figure 4 is Figure 1 A partial enlarged side view schematic of the first prism sheet of the backlight module.
[0016] Figure 5 is Figure 1 A light emitting field schematic of an embodiment of the backlight module.
[0017] Figure 6 A partial enlarged side view schematic of the second prism sheet of the backlight module of another embodiment of the present application.
[0018] Figure 7 A side view schematic of the backlight module of another embodiment of the present application.
[0019] Figure 8 is Figure 7 Light emitting field schematics of the backlight module in the sharing state and the privacy state.
[0020] Figure 9 is Figure 8 A cross-sectional view schematic of the privacy panel.
[0021] Figure 10 A side view schematic of the backlight module of another embodiment of the present application.
[0022] Figure 11 is Figure 10 A light emitting field schematic of the backlight module.
[0023] Figure 12 A side view schematic of the backlight module of another embodiment of the present application.
[0024] Figure 13 A side view schematic of the backlight module of another embodiment of the present application.
[0025] Figure 14 A side view schematic of the backlight module of another embodiment of the present application.
[0026] Figure 15 A side view schematic of the display device of an embodiment of the present application.
[0027] Figure 16 A side view schematic of the display device of another embodiment of the present application.
[0028] Figure 17is a side view schematic diagram of the display device of another embodiment of the utility model.
[0029] Mark explanation:
[0030] 100, 100a, 100b, 100c, 100d, 100e: backlight module
[0031] 110: light emitting element
[0032] 120: light guide plate
[0033] 121: light inlet surface
[0034] 122: light outlet surface
[0035] 130, 130b: inverse prism sheet
[0036] 131: plate body
[0037] 132, 132b: prism column
[0038] 140, 140b: first prism sheet
[0039] 141: first plate body
[0040] 142, 142b: first prism column
[0041] 150, 150a, 150b: second prism sheet
[0042] 151: second plate body
[0043] 152, 152a, 152b: second prism column
[0044] 160: privacy panel
[0045] 161: liquid crystal layer
[0046] 162: alignment layer
[0047] 163: electrode layer
[0048] 164: substrate
[0049] 165: polarizing sheet
[0050] 170: diffusion sheet
[0051] 171, S1, S2, S3: surface
[0052] 180: brightness enhancement film
[0053] 190: reflective sheet
[0054] 210: display panel
[0055] 200, 200a, 200b: display device
[0056] A1, A2, A3, A1b: included angle
[0057] B, B0, Bd: base angle
[0058] B1: first base angle
[0059] B2: second base angle
[0060] D, Db: direction
[0061] D1, D1b: first direction
[0062] D2, D2b: second direction
[0063] ES1, ES2, ES3: end surface
[0064] L1, L2, L3, L4: light beam
[0065] N: normal direction
[0066] P: light output luminance peak
[0067] SS1, SS2, SS3: side surface
[0068] X, Y, Z: direction DETAILED DESCRIPTION
[0069] The above and other technical contents, features and effects of the present application will be apparent from the following detailed description of a preferred embodiment, taken in conjunction with the accompanying drawings. The directional terms mentioned in the following embodiments, such as up, down, left, right, front or back, are only the directions of the accompanying drawings. Therefore, the directional terms are used for explanation, not for limiting the present application.
[0070] Figure 1 is a schematic view of a backlight module according to an embodiment of the present application. Figure 2 is Figure 1 is a partial enlarged side view of a second prism sheet of Figure 3 is Figure 1 is a partial enlarged side view of a reverse prism sheet of Figure 4 is Figure 1 is a partial enlarged side view of a first prism sheet of Figure 1 , Figure 2 , Figure 3 and Figure 4 present the perspective relationship in directions X, Y and Z. Figure 5 is Figure 1FIG. 2 shows a schematic diagram of a light emitting field of a backlight module according to an embodiment of the present application, wherein (a) is a schematic diagram of a light emitting field of a backlight module with a second prism sheet having two base angles equal to each other, and (b) is a schematic diagram of a light emitting field of a backlight module with a second prism sheet having two base angles unequal to each other.
[0071] Figure 6 FIG. 3 shows a partial enlarged side view of a second prism sheet of a backlight module according to another embodiment of the present application.
[0072] Please refer to Figure 1 and Figure 2 The backlight module 100 includes a light emitting element 110, a light guide plate 120, a reverse prism sheet 130, a first prism sheet 140, and a second prism sheet 150. The light guide plate 120 has a light incident surface 121 and a light emitting surface 122 connected to each other, and the light incident surface 121 is opposite to the light emitting element 110. The reverse prism sheet 130 is disposed on the light emitting surface 122 of the light guide plate 120. The reverse prism sheet 130 has a plate body 131 and a plurality of prism columns 132. The prism columns 132 are disposed on a side of the plate body 131 facing the light emitting surface 122, and the prism columns 132 extend toward a direction D, wherein the direction D is substantially the same as the direction Y. The first prism sheet 140 is disposed on a side of the reverse prism sheet 130 opposite to the light guide plate 120, and the first prism sheet 140 has a first plate body 141 and a plurality of first prism columns 142. The first prism columns 142 are disposed on a side of the first plate body 141 opposite to the reverse prism sheet 130, and the first prism columns 142 extend toward a first direction D1, wherein the first direction D1 is substantially the same as the direction X. An included angle A1 between the direction D and the first direction D1 is between 85-95 degrees, and the included angle A1 of the present embodiment is about 90 degrees, for example. The second prism sheet 150 is disposed on a side of the first prism sheet 140 opposite to the reverse prism sheet 130, and the second prism sheet 150 has a second plate body 151 and a plurality of second prism columns 152. The second prism columns 152 are disposed on a side of the second plate body 151 opposite to the first prism sheet 140, and the second prism columns 152 extend toward a second direction D2, wherein the second direction D2 is substantially the same as the direction Y. An included angle A2 between the first direction D1 and the second direction D2 is between 85-95 degrees, and the included angle A2 of the present embodiment is about 90 degrees, for example. Each of the second prism columns 152 has two base angles B connecting a surface S1 of the second plate body 151, and each of the two base angles B is between 51-61 degrees.
[0073] The light emitting element 110 can include a light emitting diode (LED). Further, the number of the light emitting diodes can be multiple, and the light emitting wavelength can include blue light or white light, but the present application is not limited thereto.
[0074] Please continue to refer to Figure 1The light guide plate 120 can guide the light beam generated by the light emitting element 110 to the inverse prism sheet 130. In the embodiment, the material of the light guide plate 120 can include Polymethyl methacrylate (PMMA); however, in other embodiments, the material of the light guide plate 120 can include Cyclo olefin polymer (COP) or Polycarbonate (PC). In addition, the light guide plate 120 of the embodiment can be made by heat compression molding or injection molding.
[0075] Please refer to Figure 1 with Figure 3 , Figure 3 In order to facilitate the description, the inverse prism sheet 130 has the side of the prism column 132 facing upward in the embodiment, and the specific orientation of the prism column 132 is still described with reference to Figure 1 The plate body 131 of the inverse prism sheet 130 is arranged opposite to the light guide plate 120, for example, and the prism column 132 is fixed to the surface S2 of the plate body 131 facing the light emitting surface 122. The prism column 132 can have two end surfaces ES1 opposite to each other, wherein the two end surfaces ES1 are respectively perpendicular to the surface S2, and the direction D is directed from one of the end surfaces ES1 to the other end surface ES1. For example, the direction D of the embodiment can be substantially parallel to the surface S2. In an embodiment, the included angle A3 between the normal direction N of the light incident surface 121 and the direction D is, for example, between -5 and +5 degrees, so as to increase the light emitting brightness of the large viewing angle of the backlight module 100 in the horizontal viewing angle. It should be noted that the horizontal viewing angle described herein refers to rotating the center point of the light emitting surface 122 of the light guide plate 120 by different angles on a virtual plane parallel to the light incident surface 121 of the light guide plate 120 to view the center point of the light emitting surface 122 of the light guide plate 120, and the vertical viewing angle refers to rotating the center point of the light emitting surface 122 of the light guide plate 120 by different angles on a virtual plane perpendicular to the light incident surface 121 of the light guide plate 120 to view the center point of the light emitting surface 122 of the light guide plate 120. For example, the included angle A3 can be about 0 degrees, i.e., the normal direction N and the direction D can be substantially parallel to each other, or the direction D is substantially perpendicular to the light incident surface 121 of the light guide plate 120. In addition, the prism column 132 of the inverse prism sheet 130 has two first base angles B1 connected to the plate body 131, and the angles of the two first base angles B1 can be between 42 and 48 degrees, respectively. For example, in an embodiment, the angles of the two first base angles B1 can be about 45 degrees, i.e., the two end surfaces ES1 of the prism column 132 can be substantially isosceles right triangles. It should be noted that each prism column 132 has two side surfaces SS1 perpendicular to the surface S2 of the plate body 131, and each two side surfaces SS1 are connected to each two end surfaces ES1. The two first base angles B1 are the included angles between the two side surfaces SS1 and the surface S2 of the plate body 131.
[0076] Please refer to Figure 1 withFigure 4 The first prism sheet 140 is disposed opposite the prism sheet 130, and the first prism column 142 is fixed to a surface S3 of the first plate body 141 facing away from the prism sheet 130. Similarly, the first prism column 142 has opposite end surfaces ES2 standing on the surface S3, and the first direction D1 is directed from one of the end surfaces ES2 to the other end surface ES2, and the first direction D1 can be substantially parallel to the surface S3. The first prism column 142 of the first prism sheet 140 has two second base angles B2 connected to the first plate body 141, and the two second base angles B2 can be respectively between 42-48 degrees. For example, in an embodiment, the two second base angles B2 can be respectively about 45 degrees, i.e. the two end surfaces ES2 of the first prism column 142 can be substantially isosceles right triangles, but the present application is not limited thereto. Similarly, in the present embodiment, the two first base angles B1 are the angles between the two side surfaces SS2 of the first prism column 142 and the surface S3.
[0077] Please refer to Figure 1 and Figure 2 The second prism sheet 150 is disposed opposite the first prism sheet 141, and the second prism column 152 is fixed to a surface S1 of the second plate body 151 facing away from the first prism sheet 140. Similarly, the second prism column 152 has opposite end surfaces ES3 standing on the surface S1, and the second direction D2 is directed from one of the end surfaces ES3 to the other end surface ES3, and the second direction D2 can be substantially parallel to the surface S1. In an embodiment, the second direction D2 is substantially perpendicular to the first direction D1 of the first prism column 142, and can be substantially parallel to the direction D of the prism column 132. The large viewing angle light emitting brightness of the backlight module 100 in the horizontal viewing angle can be adjusted by the angles of the two base angles B of the second prism column 152. For example, in an embodiment, the two base angles B can be about 59 degrees, so as to increase the light emitting brightness of about +50 degrees and -50 degrees in the horizontal viewing angle. However, the present application does not limit the angles of the two base angles B. It should be noted that in the present embodiment, each second prism column 152 has two side surfaces SS3 standing on the surface S1, and each of the two side surfaces SS3 connects each of the two end surfaces ES3. The two base angles B are the angles between the two side surfaces SS3 and the surface S1.
[0078] In addition, the two base angles B of each second prism column 152 have equal or unequal angles. For example, the two base angles B of the present embodiment can have equal angles, so as to guide the light beams L1 and L2 to be respectively emitted from the two side surfaces SS3 at similar angles to each other, so that the backlight module 100 can generate a substantially symmetrical light pattern in the horizontal viewing angle, for example Figure 5the maximum luminance is approximately located at 0 degree of the horizontal viewing angle, and other luminance is greater at about +50 degrees and -50 degrees of the horizontal viewing angle, which is about 75% of the maximum luminance. In Figure 6 In the embodiment shown in (b), one of the two base angles B is changed, for example, from 59 degrees to 45 degrees, so that the two base angles B are 45 degrees and 59 degrees, respectively. The maximum luminance is also approximately located at 0 degree of the horizontal viewing angle, but other luminance is greater at about -58 degrees of the horizontal viewing angle, which is about 75% of the maximum luminance. Figure 5 In the embodiment shown in (b), one of the two base angles B is changed, for example, from 59 degrees to 45 degrees, so that the two base angles B are 45 degrees and 59 degrees, respectively. The maximum luminance is also approximately located at 0 degree of the horizontal viewing angle, but other luminance is greater at about -58 degrees of the horizontal viewing angle, which is about 75% of the maximum luminance. Figure 5 In the embodiment shown in (a), the position of the greater luminance at -50 degrees of the horizontal viewing angle is changed to Figure 5 In the embodiment shown in (b), the position of the greater luminance at -50 degrees of the horizontal viewing angle is changed to Figure 6 In an embodiment, the angle difference between the base angles B and B0 of the second prism column 152a can be less than or equal to 3 degrees, but the present application is not limited thereto.
[0079] Compared with the known technology, the backlight module 100 of the present embodiment sequentially arranges the inverse prism sheet 130, the first prism sheet 140, and the second prism sheet 150 on the light guide plate 120, wherein the inverse prism sheet 130 can guide light to be incident on the first prism sheet 140 in a substantially normal direction, and the first prism sheet 140 and the second prism sheet 150 can guide light to be emitted at a large angle, thereby increasing the luminance of light emitted at a large angle in the vertical viewing angle and the horizontal viewing angle, respectively. In addition, the base angle B of the second prism column 152 is between 51 and 61 degrees, so that light can be emitted at a larger angle, thereby further increasing the viewing angle of the backlight module 100 in the horizontal viewing angle. Therefore, the backlight module 100 of the present embodiment can effectively increase the luminance of light emitted at a large angle without increasing the power consumption of the light emitting element 110, and can solve the problems of energy waste and reduced product life.
[0080] Figure 7 FIG. 1 is a side view of a backlight module according to another embodiment of the present application. Figure 8 FIG. 2 is a side view of a backlight module according to another embodiment of the present application. Figure 7 FIG. 3 is a schematic view of the light field pattern of the backlight module of FIG. 2 in a sharing state and a privacy state. Figure 9 FIG. 4 is a cross-sectional view of a privacy panel according to another embodiment of the present application. Figure 8 The structure and advantages of the backlight module 100a of the present embodiment are similar to those of the embodiment of FIG. 1, and only the differences are described below. Please refer to FIG. 1 first. Figure 1 Figure 7 Figure 8 The backlight module 100a further includes a privacy panel 160, which is disposed on a side of the second prism sheet 150 facing away from the first prism sheet 140. In other words, the backlight module 100a may be formed by Figure 1 The backlight module 100 is formed by combining the anti-peep panel 160. Specifically, the anti-peep panel 160 can control the light emission angle of the backlight module 100, so that the backlight module 100a can switch between the anti-peep state and the sharing state. Since the inverse prism sheet 130, the first prism sheet 140 and the second prism sheet 150 can increase the light output brightness of the backlight module 100 at a large viewing angle, the backlight module 100a can provide a sufficiently large viewing angle in the sharing state. For example, please refer to Figure 8 (a), when the backlight module 100a is in the sharing state, the light output brightness at the horizontal viewing angle between 40 degrees and 60 degrees and -40 degrees and -60 degrees is significantly increased, that is, the viewing angle of the backlight module 100a in the sharing state is significantly increased. In addition, please refer to Figure 7 and Figure 8 (b) When the backlight module 100a is in the anti-peeping state, the brightness of the light emitted at a horizontal viewing angle greater than approximately 25 degrees and less than -25 degrees is significantly reduced, while the brightness of the light emitted at a horizontal viewing angle near approximately 0 degrees is significantly increased. It is worth noting that part of the light emitted by the light guide plate 120 is guided by the inverse prism sheet 130, the first prism sheet 140, and the second prism sheet 150 and emitted at a large horizontal angle. Therefore, the brightness of the light emitted by the backlight module 100a at small angles (for example, approximately 25 degrees and -25 degrees horizontal viewing angle) can be slightly reduced, thereby narrowing the viewing angle of the backlight module 100a in the anti-peeping state, thereby improving the anti-peeping effect.
[0081] Please refer to Figure 9 Incidentally, in one embodiment, the anti-peep panel 160 may include a liquid crystal layer 161, two alignment layers 162, two electrode layers 163, two substrates 164 and two polarizers 165. Specifically, the liquid crystal layer 161 is sandwiched between the two alignment layers 162, wherein each alignment layer 162 may have a groove (not shown), and the groove can allow the long axis of the liquid crystal molecules of the liquid crystal layer 161 to be arranged in the same direction when no voltage is applied. The two electrode layers 163 are respectively located on the opposite outer sides of the two alignment layers 162. When the two electrode layers 163 are transmitted with a voltage to form an electric field between the two electrode layers 163, the liquid crystal molecules of the liquid crystal layer 161 are driven to rotate and change the emission angle of the light. The two substrates 164 may be located on the opposite outer sides of the two electrode layers 163, and the two polarizers 165 are located on the opposite outer sides of the two substrates 164. It can be understood that in other embodiments, the features of the anti-peep panel 160 are not limited to Figure 9 shown.
[0082] Figure 10It is a side view schematic diagram of a backlight module according to another embodiment of the present invention. Figure 11 yes Figure 10 The structure and advantages of the backlight module 100b of this embodiment are similar to those of Figure 1 The following only describes the differences. Figure 10 and Figure 11 The angle A1b between the normal direction N of the light incident surface 121 of the light guide plate 120 and the direction Db can be between -10 and 30 degrees, preferably between 10 and 20 degrees. Figure 1 The prism 132, the first prism 142 and the second prism 152 are rotated by -10 to 30 degrees in a manner parallel to the light emitting surface 122, preferably by 10 to 20 degrees, that is, the direction Db of the prism 132b, the first direction D1b of the first prism sheet 140b and the second direction D2b of the second prism 152b are respectively opposite to each other. Figure 1 The direction D, the first direction D1 and the second direction D2 are rotated -10 to 30 degrees (preferably 10 to 20 degrees) in a manner parallel to the light emitting surface 122, thereby changing the angle A1b to between -10 and 30 degrees (preferably between 10 and 20 degrees). In this way, the two light output brightness peaks P of the backlight module 100b at a large angle can slightly deviate from the horizontal viewing angle, so that the two light output brightness peaks P of the backlight module 100b at a large angle have a slight difference in height. For example, the backlight module 100b can be applied to a car display to facilitate the main driver to view the display content in front of the co-driver. In addition, in one embodiment, the backlight module 100b can be used with Figure 7 The anti-peeping panel 160 provides two usage modes: sharing mode and anti-peeping mode.
[0083] Figure 12 This is a side view of a backlight module according to another embodiment of the present invention. The structure and advantages of the backlight module 100c of this embodiment are similar to those of Figure 1 The following only describes the differences. Figure 12 The backlight module 100c may further include a diffuser 170 disposed between the light guide plate 120 and the inverse prism sheet 130 to improve the uniformity of light emitted from the backlight module 100c. Specifically, the surface 171 of the diffuser 170 may have multiple microstructures, or a plurality of reflective particles may be disposed within the diffuser 170. The present invention does not impose any restrictions on the specific structure of the diffuser 170.
[0084] Figure 13 is a side view schematic diagram of a backlight module according to another embodiment of the present invention, wherein Figure 13 The perspective is different fromFigure 12 The structure and advantages of the backlight module 100d of the present embodiment are similar to those of the embodiment of Figure 1 The differences will be described below. Please refer to Figure 13 The backlight module 100d can further include a brightness enhancement film 180 disposed on the side of the second prism sheet 150 opposite to the first prism sheet 140 to improve the brightness of the backlight module 100d. The brightness enhancement film 180 can include, for example, a reflective brightness enhancement film (DBEF), but the present application is not limited thereto. In an embodiment, the backlight module 100d can be configured with the privacy panel 160 of Figure 7 The privacy panel 160 can be disposed on the side of the brightness enhancement film 180 opposite to the second prism sheet 150. Incidentally, since the backlight module 100d is configured with the brightness enhancement film 180, in an embodiment, the angle of the two base angles Bd of the second prism sheet 150 can be about 57 degrees to increase the brightness of the backlight module 100d in the horizontal viewing angle of about 50 degrees and -50 degrees, but the present application is not limited to the angle of the base angle Bd.
[0085] Figure 14 is a side view schematic diagram of a backlight module of another embodiment of the present application. The structure and advantages of the backlight module 100e of the present embodiment are similar to those of the embodiment of Figure 1 The differences will be described below. Please refer to Figure 14 The backlight module 100e can further include, for example, a reflective sheet 190 disposed on the side of the light guide plate 120 opposite to the inverse prism sheet 130 to improve the light utilization rate of the backlight module 100e. In the present embodiment, the material of the reflective sheet 190 can include silver, but the present application is not limited thereto.
[0086] Figure 15 is a side view schematic diagram of a display device of an embodiment of the present application. Please refer to Figure 15 The display device 200 includes the backlight module 100 and a display panel 210. The display panel 210 is disposed on the side of the second prism sheet 150 opposite to the first prism sheet 140. In the present embodiment, the display panel 210 can include a liquid crystal display panel, and the backlight module 100 can provide light to the display panel 210. However, the present application is not limited to the type of the display panel 210.
[0087] Compared with the known art, the display device 200 of the present embodiment adopts the backlight module 100, so that the viewing angle can be effectively increased, and the problems of energy waste and product life reduction can be improved. In other embodiments, the display device 200 can adopt the backlight module 100a, 100b, 100c, 100d or 100e.
[0088] Figure 16 This is a side view of a display device according to another embodiment of the present invention. The structure and advantages of the display device 200a of this embodiment are similar to those of Figure 15 The following only describes the differences. Figure 16 The backlight module 100a may further include an anti-peeping panel 160, which is disposed between the second prism sheet 150 and the display panel 210. In other words, the display device 200a adopts Figure 7 The backlight module 100a is combined with the display panel 210, so that the display device 20a has two usage modes: sharing mode and anti-peeping mode. The features of the anti-peeping panel 160 have been described in detail above, so the relevant description is omitted here.
[0089] Figure 17 The structure and advantages of the display device 200b of this embodiment are similar to those of Figure 15 The following only describes the differences. Figure 17 The display device 200b may further include an anti-peeping panel 160, which is disposed on a side of the display panel 210 facing away from the second prism sheet 150, so that the display device 200b has two usage modes: a sharing mode and an anti-peeping mode.
[0090] 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 arranges the inverse prism sheet, the first prism sheet and the second prism sheet on the light guide plate in sequence, wherein the inverse prism sheet can guide the light to be incident roughly in the forward direction to the first prism sheet, and the first prism sheet and the second prism sheet respectively guide the light to be emitted at a large angle, thereby increasing the brightness of the light output at a large viewing angle in the vertical and horizontal viewing angles respectively. In addition, the bottom angle of the second prism column is between 51 and 61 degrees, which can guide the light to be emitted at a larger angle, thereby further increasing the viewing angle of the backlight module at a horizontal viewing angle. Therefore, the backlight module of the present invention can effectively increase the brightness of the light output at a large viewing angle without increasing the power consumption of the light-emitting element, and improve the problems of energy waste and reduced product life. The display device of the present invention adopts the above-mentioned backlight module, so it can effectively increase the viewing angle and also improve the problems of energy waste and reduced product life.
[0091] The above are only preferred embodiments of the present utility model, and cannot limit the scope of the present utility model, that is, simple equivalent changes and modifications made according to the claims and contents of the present utility model still fall within the scope of the present utility model. In addition, any embodiment or claim of the present utility model does not need to achieve all the purposes or advantages or features disclosed by the present utility model. Furthermore, the abstract and title (utility model name) are only used to assist patent document retrieval and do not limit the scope of the present utility model. In addition, the terms "first", "second", etc. mentioned in the specification or claims are only used to name elements or distinguish different embodiments or ranges, and do not limit the upper or lower limit of the number of elements.
Claims
1. A backlight module, characterized by, The backlight module comprises a light emitting element, a light guide plate, an inverse prism sheet, a first prism sheet and a second prism sheet, wherein: The light guide plate has a light incident surface and a light exit surface connected to each other, and the light incident surface is opposite to the light emitting element; The inverse prism sheet is arranged on the light exit surface of the light guide plate, and has a plate body and a plurality of prism columns arranged on a side of the plate body facing the light exit surface, and the plurality of prism columns extend in a direction; The first prism sheet is arranged on a side of the inverse prism sheet opposite to the light guide plate, and has a first plate body and a plurality of first prism columns arranged on a side of the first plate body opposite to the inverse prism sheet, and the plurality of first prism columns extend in a first direction, and an included angle between the direction and the first direction is between 85-95 degrees; and The second prism sheet is arranged on a side of the first prism sheet opposite to the inverse prism sheet, and has a second plate body and a plurality of second prism columns arranged on a side of the second plate body opposite to the first prism sheet, and the plurality of second prism columns extend in a second direction, and an included angle between the first direction and the second direction is between 85-95 degrees, wherein each of the plurality of second prism columns has two base angles connecting a surface of the second plate body, and each of the two base angles is between 51-61 degrees.
2. The backlight module of claim 1, wherein, An included angle between a normal direction of the light incident surface and the direction is between -5-+5 degrees.
3. The backlight module of claim 1, wherein, An included angle between a normal direction of the light incident surface and the direction is between -10-30 degrees.
4. The backlight module of claim 1, wherein, The two base angles of each of the plurality of second prism columns have equal or unequal angles.
5. The backlight module of claim 4, wherein, An angle difference between the two base angles is less than or equal to 3 degrees.
6. The backlight module of claim 1, wherein, The plurality of prism columns of the inverse prism sheet respectively have two first base angles connecting the plate body, the plurality of first prism columns of the first prism sheet respectively have two second base angles connecting the first plate body, and the two first base angles and the two second base angles respectively have angles between 42-48 degrees.
7. The backlight module of claim 1, wherein, The backlight module further comprises a privacy panel, wherein the privacy panel is arranged on a side of the second prism sheet opposite to the first prism sheet.
8. The backlight module of claim 1, wherein, The backlight module further comprises a diffusion sheet, wherein the diffusion sheet is arranged between the light guide plate and the inverse prism sheet.
9. The backlight module of claim 1, wherein, The backlight module further comprises a brightness enhancement sheet, wherein the brightness enhancement sheet is arranged on a side of the second prism sheet opposite to the first prism sheet.
10. The backlight module of claim 1, wherein, The backlight module further comprises a reflective sheet, wherein the reflective sheet is arranged on a side of the light guide plate opposite to the inverse prism sheet.
11. A display device, characterized by comprising: The display device comprises a backlight module and a display panel, wherein: The backlight module comprises a light emitting element, a light guide plate, an inverse prism sheet, a first prism sheet and a second prism sheet, wherein: The light guide plate has a light incident surface and a light exit surface connected to each other, and the light incident surface is opposite to the light emitting element; The inverse prism sheet is disposed on the light exit surface of the light guide plate, and has a plate body and a plurality of prism columns disposed on a side of the plate body facing the light exit surface, the plurality of prism columns extending in a direction; The first prism sheet is disposed on a side of the inverse prism sheet opposite to the light guide plate, and has a first plate body and a plurality of first prism columns disposed on a side of the first plate body opposite to the inverse prism sheet, the plurality of first prism columns extending in a first direction, and an included angle between the direction and the first direction is between 85 and 95 degrees; and The second prism sheet is disposed on a side of the first prism sheet opposite to the inverse prism sheet, and has a second plate body and a plurality of second prism columns disposed on a side of the second plate body opposite to the first prism sheet, the plurality of second prism columns extending in a second direction, and an included angle between the first direction and the second direction is between 85 and 95 degrees, wherein each of the plurality of second prism columns has two base angles connecting a surface of the second plate body, and each of the two base angles is between 51 and 61 degrees; and The display panel is disposed on a side of the second prism sheet opposite to the first prism sheet.
12. The display device according to claim 11, wherein The backlight module further comprises a privacy panel disposed between the second prism sheet and the display panel.
13. The display device of claim 11, wherein, The display device further comprises a privacy panel disposed on a side of the display panel opposite to the second prism sheet.