Display device

Abstract

To improve the intensity of a part where a hole is formed.SOLUTION: The display device includes: a display panel; and a housing part for surrounding the rear surface, the side surfaces, and the front peripheral edge portion of the display panel. The housing part includes a rear cover facing the rear surface of the display panel. The rear cover includes a plurality of linear portions that extend in a first direction parallel to the display panel and are arranged in parallel with spaces between the linear portions, and a plurality of connecting portions that extend so as to connect adjacent ones of the plurality of linear portions. The connecting portions are positioned at locations deeper with respect to the display panel than the rear surface at the adjacent linear portions.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present technology relates to a display device having a structure formed by injection molding. [Background technology]

[0002] Some display devices, such as televisions, have a structure formed by injection molding. In such display devices, for example, the rear cover, which is part of the outer casing, may be formed by injection molding. The rear cover has multiple holes formed therein for absorbing and exhausting air to cool the heat generated inside the outer casing (see, for example, Patent Document 1). The portion having these multiple holes is formed in a lattice pattern. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2011-095772 Summary of the Invention [Problem to be solved by the invention]

[0004] When forming the lattice-shaped portion by injection molding, the molten resin splits and merges, and weld lines may form at the points where the molten resin merges. The area where a weld line has formed has lower strength than other areas, so the occurrence of a weld line can cause cracks or chipping. For example, if cracks or chipping occur during impact testing of a product, countermeasures will be required.

[0005] The present technology has been made in view of such problems, and aims to improve the strength of the portion where the hole is formed. [Means for solving the problem]

[0006] The display device according to the present technology includes: The display device includes a display panel and an outer casing that surrounds the rear, sides, and front periphery of the display panel. The outer casing has a rear cover that faces the rear surface of the display panel. The rear cover is parallel to the display panel.Extends in the first direction spaced apart and parallel a plurality of straight sections; Adjacent straight line portions The straight line Department Concatenate Multiple lines extending like this A connecting portion and the connecting portion is located at a position deeper than the rear surface of the adjacent linear portion relative to the display panel. It is something. This creates holes between the straight sections. Furthermore, during injection molding, the flow rate of the molten resin when forming the base section is faster than the flow rate of the molten resin when forming the connecting section. Therefore, a weld line (a point where the molten resin split by the holes meets) is likely to form at the connecting section.

[0007] In the display device described above, a plurality of the connecting portions may be provided spaced apart in the first direction. This improves the strength of the straight portion.

[0008] In the above-mentioned display device, the pitch width a of adjacent connecting portions in the first direction, the length b of the connecting portions in the second direction, the thickness t1 of the base portion in the third direction, and the thickness t2 of the connecting portions in the third direction may satisfy the following formula: (t1 / t2) 3 >a / b This makes it easier for weld lines to form at the joints.

[0009] In the above-described display device, the pitch width a may be larger than the length b. As a result, the space surrounded by the linear portion and the connecting portion becomes an elongated hole.

[0010] In the above-described display device, the thickness t1 may be greater than the thickness t2. This allows the flow rate of the molten resin when forming the connecting portion to be slower than the flow rate of the molten resin when forming the base portion of the straight portion.

[0011] In the display device described above, the thickness t1 may be greater than the thickness t3 of the protruding portion in the second direction. This allows the flow rate of the molten resin when forming the protruding portion to be slower than the flow rate of the molten resin when forming the base of the straight portion.

[0012] In the above-described display device, the thickness t2 and the thickness t3 may be the same thickness. This prevents the thickness of either the connecting portion or the protruding portion from being excessively thin.

[0013] In the above-described display device, at least a portion of outer surfaces on both sides of the straight portion in the second direction may be formed as inclined surfaces that approach each other in the second direction as they move away from the connecting portion in the third direction. This reduces the cross-sectional area of ​​the space in the mold used for injection molding where the continuous portion between the base and the protrusion is formed, making it difficult for molten resin to flow into the protrusion.

[0014] The display device includes a rear cover disposed behind the display panel, The linear portion and the connecting portion may be provided on the rear cover. This makes it easy for weld lines to form at the connecting portions of the rear cover.

[0015] In the above-described display device, the base portion may be located on the outer surface side of the connecting portion. As a result, the connecting portion, where a weld line is likely to form, is positioned closer to the internal space of the display device than the base portion.

[0016] In the display device described above, a space surrounded by the linear portions adjacent to each other and the connecting portions adjacent to each other in the first direction may be formed as an intake / exhaust hole. This allows heat generated from the electronic substrate and the like to be released through the intake and exhaust holes, and also allows the strength of the structure that forms the intake and exhaust holes to be maintained at a certain level or higher. [Brief explanation of the drawings]

[0017] [Figure 1]FIG. 1 is a perspective view of a display device. [Figure 2] FIG. 2 is a perspective view of the display device in a direction different from that of FIG. [Figure 3] FIG. [Figure 4] FIG. 4 is an end view taken along line AA in FIG. 3. [Figure 5] 10 is a schematic view showing a state in which an impact is applied to the outer surface of the rear cover and the rear cover is elastically deformed; FIG. [Figure 6] FIG. 4 is an end view taken along line BB in FIG. 3. [Figure 7] FIG. 4 is an end view taken along line CC in FIG. 3. [Figure 8] FIG. 10 is a rear view showing a process in which the rear cover is formed from molten resin. [Figure 9] FIG. 9 is an end view taken along line FF in FIG. 8. [Figure 10] 8, showing the process of forming the rear cover with molten resin. FIG. [Figure 11] FIG. 11 is an end view taken along line FF in FIG. [Figure 12] 11 is a rear view showing the process of forming the rear cover with molten resin, following FIG. 10. FIG. [Figure 13] FIG. 13 is an end view taken along line FF in FIG. [Figure 14] 13 is a rear view showing the process of forming the rear cover with molten resin, following FIG. 12. FIG. [Figure 15] FIG. 15 is an end view taken along line FF in FIG. [Figure 16] FIG. 10 is an end view showing the thickness of the base, the thickness of the protrusion, and the thickness of the connecting portion. [Figure 17] FIG. 10 is an end view illustrating an example in which the time it takes for molten resin to flow through the protruding portion is taken into consideration. [Figure 18] FIG. 10 is a schematic diagram showing an example of dimensions. [Figure 19] 10A and 10B are a cross-sectional view and an end view showing a straight portion and a connecting portion in a modified example. [Figure 20]FIG. 10 is a diagram showing that one end of the connection portion is formed as a coupling portion. DETAILED DESCRIPTION OF THE INVENTION

[0018] The embodiments will be described below in the following order. <1. Display device configuration> <2. Rear cover structure> <3. Rear cover molding process in injection molding> <4. Pressure loss of molten resin> <5. Dimension example> <6. Variations> <7. Summary> <8. This Technology>

[0019] <1. Display device configuration> The configuration of a display device 1 of the present technology will be described with reference to Fig. 1 and Fig. 2. The display device 1 is, for example, a device that displays videos and images, such as a television device or a monitor device.

[0020] The display device 1 comprises a display unit 2 having an approximately rectangular shape, a support unit 3 attached to the rear surface of the display unit 2 and extending in the vertical direction, and a base unit 4 to which the lower end of the support unit 3 is attached and which has a horizontally flat shape to stabilize the posture of the display unit 2 and the support unit 3.

[0021] In the following description, the front-to-rear direction will be described assuming that the user viewing the video (image) displayed on the display device 1 is the front. In addition, the direction of gravity will be referred to as the up-down direction, and the horizontal direction will be referred to as the left-to-right direction. Note that the left-to-right direction will be used as viewed from the rear side of the display device 1.

[0022] The terms "first direction," "second direction," and "third direction" used in the claims refer to the above-mentioned up-down direction, left-right direction, and front-rear direction, respectively. However, these directions correspond to the opening directions of the intake and exhaust holes, which will be described later. Specifically, since the intake and exhaust holes described in this embodiment are holes that open rearward, the first direction is the up-down direction. For example, if the intake and exhaust holes are holes that open downward, the first direction is the front-rear direction, the second direction is the left-right direction, and the third direction is the up-down direction. It should be noted that these directions are merely for the convenience of explanation, and the implementation of the present technology is not limited to these directions.

[0023] The display unit 2 comprises an outer casing 5 having an opening at the front and housing various components such as electronic circuits for displaying images, etc., therein, and a display panel 6 on which images, etc. are displayed and which is arranged so that the images, etc. can be seen from the front through the opening of the outer casing 5.

[0024] The outer casing 5 is composed of, for example, a bezel 7 formed as the front part, a rear cover 8 formed as the rear part and positioned behind the display panel 6, and various controls not shown.

[0025] The bezel 7 includes an upper surface portion 9 facing up and down and extending left and right, a pair of side surfaces 10, 10 facing left and right and continuing to both left and right ends of the upper surface portion 9 and extending up and down, a lower surface portion 11 facing up and down and having both left and right ends continuing to the lower ends of the pair of side surfaces 10, 10, and a frame-shaped portion 12 facing front and rear. The outer periphery of the frame-shaped portion 12 is continuous with the front ends of the upper surface portion 9, the side surfaces 10, 10 and the lower surface portion 11.

[0026] The rear cover 8 is a resin member formed by injection molding into a plate shape facing forward and backward, and is attached to the rear end of the bezel 7 from behind. The rear cover 8 is provided with intake holes for taking in air into the internal space and exhaust holes for expelling air from the internal space. These intake holes and exhaust holes cool the heat emitted from the substrates and the like arranged inside the display unit 2. These intake holes and exhaust holes will be collectively referred to as intake and exhaust holes 13.

[0027] The intake and exhaust holes 13 are provided in multiple locations on the rear cover 8, such as holes that open rearward, downward, upward, or to the side. Alternatively, the intake and exhaust holes 13 may be not only holes that open in these directions, but also holes that open in an oblique direction. The portion where the multiple intake and exhaust holes 13 are formed is provided in a lattice shape. The intake and exhaust holes 13 may be provided in the bezel 7. For example, the intake and exhaust holes 13 shown in Fig. 2 are exemplified as holes formed in the back cover 8 that open rearward and holes formed in the lower surface portion 11 of the bezel 7 that open downward. The following description will focus on the intake and exhaust holes 13 that are opened behind the rear cover 8. The intake and exhaust holes 13 may have various shapes, but in this example, an intake and exhaust hole 13 that is elongated in the vertical direction will be used as an example.

[0028] The display panel 6 has a layered structure made up of a diffusion plate, an optical sheet, a wiring layer, and the like.

[0029] <2. Rear cover structure> The specific configuration of the rear cover 8 will be described with reference to FIG.

[0030] The rear cover 8 is made up of a central portion 14 in which a plurality of intake and exhaust holes 13 are formed, and an outer peripheral portion 15 which is the remaining portion.

[0031] The outer peripheral portion 15, excluding the outermost edge portion 15a, has a plurality of straight portions 16 extending in the vertical direction and positioned at a distance in the horizontal direction, and connecting portions 17 positioned between the straight portions 16. Recesses that are open to the rear are formed between adjacent straight portions 16, 16.

[0032] Next, the straight portion 16 and the connecting portion 17 will be described with reference to FIG.

[0033] The straight portion 16 has a base 18 that extends in the vertical direction and has an approximately rectangular parallelepiped shape, and a pair of protrusions 19, 19 that protrude forward from both left and right ends of the base 18, extend in the vertical direction, and have an approximately rectangular parallelepiped shape. Here, the protrusion 19 protruding from the left end of the base 18 is referred to as protrusion 19L, and the protrusion 19 protruding from the right end is referred to as protrusion 19R. When there is no need to distinguish between the left and right protrusions, they are simply referred to as protrusions 19.

[0034] The left and right ends of the connecting portion 17 are connected to the tip end 20 of the protruding portion 19R of the straight portion 16 and the tip end 20 of the protruding portion 19L of the adjacent straight portion 16, respectively.

[0035] The rear surface of the base 18 is formed as part of the outer surface 21 of the display device 1. The outer surface 21 may be subjected to, for example, a surface treatment to remove unevenness and make it smooth, or a embossing treatment to form unevenness. The outer surface 21 is also a part to which an impact is applied in an impact test. Furthermore, the outer surface 21 is one of the parts that is likely to receive an impact from a user or the like after commercialization.

[0036] The rear cover 8 has an uneven horizontal cross-sectional shape (bellows shape) due to the straight portions 16 and the connecting portions 17. When an impact is applied to the rear cover 8, as shown in Fig. 5, in the vicinity of point D where the impact was applied, each portion of the rear cover 8 is deformed so that adjacent base portions 18, 18 approach each other and the gap between the pair of protrusions 19L, 19R of the straight portion 16 widens.

[0037] Therefore, an impact applied to the rear cover 8 is absorbed by the distortion before being transmitted to the connecting portions 17 and the protruding portions 19, so that no large stress is generated in the connecting portions 17 and the protruding portions 19.

[0038] Next, the central portion 14 of the rear cover 8 will be described with reference to FIGS.

[0039] The central portion 14 of the rear cover 8 has a plurality of straight portions 16 spaced apart in the left-right direction and a plurality of connecting portions 22 spaced apart in the up-down direction. In other words, a plurality of connecting portions 22 are provided between two adjacent straight portions 16, 16, thereby improving the strength of the straight portions 16.

[0040] 7, the connecting portion 22 has the same shape in horizontal cross section as the connecting portion 17. That is, the connecting portion 22 has a rectangular parallelepiped shape extending in the left-right direction, and both left and right ends are connected to the tip end 20 of the protruding portion 19R of the straight portion 16 and the tip end 20 of the protruding portion 19L of the adjacent straight portion 16, respectively. The multiple connecting portions 22 are provided spaced apart in the vertical direction.

[0041] The space surrounded by the linear portions 16, 16 adjacent to each other in the left-right direction and the connecting portions 22, 22 adjacent to each other in the up-down direction is formed as an intake / exhaust hole 13. The intake / exhaust hole 13 allows heat generated from electronic boards and the like arranged inside the outer casing 5 to be released to the outside. Therefore, good heat dissipation properties of the display device 1 can be ensured. The space surrounded by the linear portions 16, 16 adjacent to each other in the left-right direction, the end of the connecting portion 17, and the connecting portion 22 also serves as the intake and exhaust hole 13.

[0042] Next, the length and thickness of each part of the rear cover 8 will be described (see FIGS. 3 and 7). The thickness of base 18 in the front-to-rear direction is thickness t1. The thickness of connecting portion 22 in the front-to-rear direction is thickness t2. The thickness of protrusion 19 in the left-to-right direction is thickness t3. The pitch width of connecting portions 22, 22 in the up-down direction is pitch width a. The length of connecting portion 22 in the left-to-right direction is length b.

[0043] In this embodiment, for example, the thickness t1 is greater than the thickness t2 and the thickness t3, and the thickness t2 and the thickness t3 are the same size. Furthermore, the pitch width a is greater than the length b. The conditions that these thicknesses and lengths must meet will be described later.

[0044] <3. Rear cover molding process in injection molding> As described above, the rear cover 8 is formed by injection molding using molten resin. The process of forming each part of the rear cover 8 by injection molding will be described below in chronological order (see FIGS. 8 to 15).

[0045] Fig. 8 is a diagram showing a state in which molten resin PL flows in from inlet position E to form the illustrated portion of rear cover 8. Inlet position E is, for example, the portion shown in Fig. 8 that is closest to a gate (not shown). Note that inlet position E shown in Fig. 8 is merely an example, and can be set arbitrarily depending on the position of the gate provided on rear cover 8. Furthermore, the number of inflow positions E does not need to be one, and a plurality of positions may be provided. The gate may be located at any position when forming the rear cover 8 by injection molding. The number of gates may be one or more.

[0046] In the following drawings, the positional relationship between the rear cover 8, which is the final molded product, and the molten resin PL (the matte finish part in the drawing) at that time is shown. Also, the flow state of the molten resin in the internal space (cavity) of the mold cut along the dashed line FF in Figure 8 etc. will be explained.

[0047] As shown in FIGS. 8 and 9, the molten resin PL flows first in the space forming the straight portion 16A, which is closer to the inflow position E than the space forming the straight portion 16B.

[0048] As described above, the thickness t1 of the base 18 in the front-rear direction is made larger than the thickness t3 of the protruding portion 19 in the left-right direction. Therefore, the speed at which the molten resin PL flows in the front-rear direction in the space where the protruding portion 19 is formed is made faster than the speed at which the molten resin PL flows in the up-down direction in the space where the base 18 is formed. This allows for a state in which the molten resin is flowing into the base 18 but not into the protruding portion 19. Therefore, the time it takes for the molten resin PL to reach the space where the connecting portion 22 is formed can be delayed, making it easier to form the weld line W in the connecting portion 22.

[0049] Next, as shown in Figures 10 and 11, the molten resin PL flows from the space forming the straight portion 16A through the space forming the protrusion 19R toward the space forming the connecting portion 22, and also flows from the space forming the base 18 of the straight portion 16B toward the space forming the protrusion 19L.

[0050] Next, as shown in Figures 12 and 13, the molten resin PL flows from the space forming the straight portion 16A to the space forming the connecting portion 22, and also flows from the space forming the protruding portion 19L toward the space forming the connecting portion 22.

[0051] 14 and 15, the molten resin PL merges in the space that forms the connecting portion 22. Therefore, a weld line W of the molten resin PL is formed in the space that forms the connecting portion 22.

[0052] As described above, the thickness t1 in the front-rear direction of the base 18 is made larger than the thickness t2 in the front-rear direction of the connecting portion 22. Therefore, the speed at which the molten resin PL flows in the left-right direction in the space forming the connecting portion 22 (see FIGS. 13 and 15) is made slower than the speed at which the molten resin PL flows in the up-down direction in the space forming the base 18 (see FIGS. 12 and 14). Therefore, the weld line W can be easily formed in the connecting portion 22.

[0053] The thickness t2 of the connecting portion 22 in the front-rear direction and the thickness t3 of the protruding portion 19 in the left-right direction may be the same thickness. In order to form the joining point of the molten resin PL at the connecting portion 22, it is possible to reduce either the thickness t3 of the protruding portion 19 or the thickness t2 of the connecting portion 22. If only one of the thicknesses t2 and t3 is reduced, the strength of the portion with the reduced thickness decreases, making it more susceptible to breakage or cracking. By making the thickness t2 of the connecting portion 22 and the thickness t3 of the protruding portion 19 the same, it is possible to make the connecting portion 22 and the protruding portion 19 thicker to a certain extent compared to when only one of the thicknesses t2 and t3 is made smaller. Therefore, it is possible to slow down the flow speed of the molten resin PL when forming the protruding portion 19 and the connecting portion 22 while ensuring the strength of the protruding portion 19 and the connecting portion 22, and it is possible to improve the durability of the rear cover 8.

[0054] As shown in the drawings, the base 18 is located on the outer surface side (rear side) of the connecting portion 22. As a result, the connecting portion 22, where the weld line W is likely to form, is located closer to the internal space of the display device 1 than the straight portion 16. Therefore, impact is less likely to be applied to the connecting portion 22 where the weld line W is likely to form, making it less likely that breakage or cracking due to the weld line W will occur, improving the durability of the rear cover 8. Furthermore, if the base 18 is the outer surface 21 of the display device 1, impact may be applied to the base 18 during an impact test. In such cases, since the weld line W is not formed on the base 18, the impact test is more likely to pass, and no countermeasures are required. Therefore, unnecessary man-hours can be reduced.

[0055] <4. Pressure loss of molten resin> The flow speed of the molten resin PL during injection molding depends on the magnitude of the pressure loss that occurs when the molten resin PL flows inside the mold. Specifically, the greater the pressure loss, the slower the flow speed. The pressure loss ΔP is calculated by the following formula (1).

[0056] ΔP = 12 μLQ / (wt 3 )...Equation (1)

[0057] μ represents the viscosity of the molten resin PL. L represents the flow distance. Q represents the flow rate of the molten resin PL. w represents the width of the flow path through which the molten resin PL flows. t represents the thickness of the flow path.

[0058] A specific example of pressure loss relating to the rear cover 8 will be described below using the pitch width a in the vertical direction of the multiple connecting portions 22 positioned spaced apart in the vertical direction and the length b of the connecting portions 22 in the horizontal direction.

[0059] In order for the weld line W to be formed in a location other than the straight portion 16, it is necessary for the molten resin PL flowing through the adjacent straight portion 16 (straight portion 16B in Figure 9) to finish forming the base 18 before the molten resin PL that formed the straight portion 16 (straight portion 16A in Figure 9) finishes forming the connecting portion 22.

[0060] To satisfy this condition, the time required to form the base 18 of the straight portion 16 over the pitch width a must be shorter than the time required to form the connecting portion 22 over the length b.

[0061] The pressure loss ΔP1 of the molten resin PL when the base portions 18 of the straight portions 16 are formed over the pitch width a can be expressed by the following formula (2) (see FIG. 16).

[0062] ΔP1=12μaQ / (w×t1 3 )...Equation (2)

[0063] Furthermore, the pressure loss ΔP2 when the molten resin PL flows from one end to the other end of the connecting portion 22 can be expressed by the following formula (3) (see FIG. 16).

[0064] ΔP2=12μbQ / (w×t2 3 )...Equation (3)

[0065] In order for the weld line W to be formed in the connecting portion 22, the pressure loss ΔP1 must be smaller than the pressure loss ΔP2. That is, the following equation (4) is derived from equations (2) and (3).

[0066] (t1 / t2) 3 >a / b...Equation (4)

[0067] By satisfying the above formula (4), during injection molding, the molten resin PL flows from the base portion 18 of the adjacent straight portion 16 into the connecting portion 22 before the molten resin PL used to form the base portion 18 forms the entire connecting portion 22. Therefore, the weld line W is not formed in the straight portion 16, and the strength of the straight portion 16 can be improved.

[0068] Note that various combinations of the variables t1, t2, a, and b that satisfy the formula (4) are possible. However, the value of variable t1 is the thickness of base 18 in the front-to-rear direction, and is determined automatically by the design, taking into account the strength and weight of rear cover 8. Furthermore, the value of variable a is the pitch width of connecting portions 22, 22 in the up-down direction, and is determined automatically, taking into account the size of intake and exhaust holes 13. Furthermore, the value of variable b is the length of connecting portion 22 in the left-to-right direction, and is determined automatically, taking into account the size of intake and exhaust holes 13.

[0069] Therefore, the value of variable t2 is derived from equation (4) based on the values ​​of variables t1, a, and b as a value less than a predetermined value.

[0070] In order to form a weld line W at the connecting portion 22, the variable t2 must be less than a predetermined value to satisfy equation (4). However, considering the durability of the rear cover 8, the thickness t2 of the connecting portion 22 in the front-to-rear direction cannot be set to an excessively small value, and it is desirable to make the variable t2 as large as possible.

[0071] Therefore, the conditions for increasing the value of the thickness t2 will be explained below. In the display device 1, it is most desirable for a weld line W to form at the connecting portion 22 in order to ensure high strength of the rear cover 8, but it is also acceptable for a weld line W to form at the protruding portion 19 or the connecting portion 22, which are parts other than the base 18, and sufficient strength of the rear cover 8 can be ensured even when a weld line W forms at the protruding portion 19.By relaxing equation (4), which is the condition for a weld line W to form at the protruding portion 19, to the condition for a weld line W to form at the protruding portion 19 or the connecting portion 22, it is possible to increase the value of variable t2 as follows.

[0072] In order to form a weld line W in the protrusion 19 or the connecting portion 22, the sum of the pressure loss of the molten resin PL when forming the protrusion 19 of the straight portion 16 and the pressure loss ΔP2 of the molten resin PL when forming the connecting portion 22 must be greater than the pressure loss ΔP1.

[0073] That is, as shown in Figure 17, if the path along which the molten resin PL flows from the space forming the protrusion 19R of the straight section 16A through the space forming the connecting section 22 to the space forming the protrusion 19L of the straight section 16B is defined as path G, it is sufficient that the pressure loss ΔP3 of the molten resin PL flowing along path G is greater than the pressure loss ΔP1.

[0074] Here, if only one of the thickness t2 in the front-to-back direction of the connecting portion 22 and the thickness t3 in the left-to-right direction of the protruding portion 19 is reduced, the strength of the reduced thickness portion may be reduced too much, so it is desirable that the thickness t2 in the front-to-back direction of the connecting portion 22 and the thickness t3 in the left-to-right direction of the protruding portion 19 be the same thickness. When the thickness t2 and the thickness t3 are the same value, the pressure loss ΔP3 is expressed by the following formula.

[0075] ΔP3=12μb'Q / (w×t2 3 )...Equation (5)

[0076] b' is the path length of the path G and can be expressed by the following equation (6).

[0077] b'=2c-t2+b+t3 =2c-t2+b+t2 =2c+b...Equation (6)

[0078] In order for the weld line W to form in the portion on the path G, i.e., the protrusion 19 or the connecting portion 22, the pressure loss ΔP3 must be greater than the pressure loss ΔP1. Therefore, the following equation (7) can be derived from equations (2), (5), and (6).

[0079] (t1 / t2) 3 >a / b' (t1 / t2) 3 >a / (2c+b)...Equation (7)

[0080] From equations (4) and (7), the thickness t2 can take on an expanded range of values ​​as follows:

[0081] Since c>0, (2c+b) is a value greater than b, and a / (2c+b) in equation (7) is a value smaller than a / b. Equation (7) indicates that (t1 / t2) may be a smaller value than equation (4). Therefore, equation (7) allows t2 to be a larger value than equation (4).

[0082] By determining the thickness t2 based on Equation (7), the thickness t2 of the protruding portion 19 and the connecting portion 22 can be increased, thereby improving the strength of the protruding portion 19 and the connecting portion 22. Furthermore, during injection molding, the molten resin PL used to form the base 18 of the straight portion 16A forms the protruding portion 19R and the connecting portion 22, and then flows from the base 18 of the adjacent straight portion 16B to the protruding portion 19L before forming the protruding portion 19L of the adjacent straight portion 16B. That is, in the mold cavity, the molten resin PL flows from the spaces forming the adjacent straight portions 16 toward the space forming the connecting portion 22 located therebetween and meets at the connecting portion 22 or the protruding portion 19. Therefore, weld lines W are not formed in the straight portion 16, further improving the strength of the straight portion 16.

[0083] In addition, by making the pitch width a of the connecting portions 22 larger than the length b of the connecting portions 22, the space surrounded by the straight portions 16 and the connecting portions 22 is formed as the elongated intake / exhaust hole 13. Therefore, it is possible to prevent fingers or foreign objects from entering the inside of the display device 1 through the elongated intake / exhaust hole 13.

[0084] Here, we have explained that the conditions for thickness t2 can be relaxed by setting variables other than thickness t2 as constants, but by changing the combination of variables that are set as constants, the conditions for variables other than thickness t2 can be relaxed.

[0085] <5. Dimension example> An example of dimensions of each part of the straight portion 16 and the connecting portion 22 is shown in FIG. The left and right ends of the rear end of the base 18 are formed as corners 18a, respectively. The inner ends of the tip ends 20, 20 of the protrusions 19L, 19R are formed as inner corners 20a, 20a, respectively.

[0086] First, it is desirable that the distance d between the protrusion 19L and the protrusion 19R protruding from one base 18 and the portion of the protrusion 19L that continues to the base 18 be 2.3 times or more the thickness t2 of the connecting portion 22 and the thickness t3 of the protrusion 19.

[0087] Considering the ease of injection molding, it is difficult to form the thickness t2 of the connecting portion 22 and the thickness t3 of the protruding portion 19 to be less than 1 mm. Therefore, for example, if the thickness t2 of the connecting portion 22 and the thickness t3 of the protruding portion 19 are 1 mm, it is desirable that the distance d be 2.1 mm or more. This makes the speed of the molten resin when forming the protrusion 19 and the connecting portion 22 sufficiently slower than the speed of the molten resin PL when forming the base 18, making it easier to form the weld line W in parts other than the base 18.

[0088] It is desirable that corners 18a and inner corners 20a are R-chamfered to prevent chipping, etc. It is desirable that corners 18a are R-chamfered to a radius of 0.5 mm to 1 mm, for example, and inner corners 20a are R-chamfered to a radius of 0.3 mm, for example.

[0089] The corners at both ends of the rear end of the connecting portion 22 are angled at 180 degrees or more, making them less likely to chip, and therefore there is no need to perform R-chamfering. Similarly, the angle of the corner provided at the connecting portion between the base portion 18 and the protruding portion 19 is 180 degrees or more, so there is no need to perform R-chamfering.

[0090] Furthermore, to facilitate the process of releasing rear cover 8 as a molded product from the mold, it is desirable to set angle r, formed between the direction in which protrusion 19 extends and the front-to-rear direction, to be greater than 0 degrees. Angle r is set to, for example, 0.5 degrees or greater.

[0091] Next, an example of the values ​​that the variables t1, t2, a, and b used in the above-mentioned equation (4) can take will be given.

[0092] The maximum value of the vertical pitch width a of the connecting portions 22 is preferably set to a predetermined value or less so as not to reduce the strength of the straight portions 16. Furthermore, from the viewpoint of heat dissipation efficiency, it is preferable that the pitch width a be set to a predetermined value or more. For example, the pitch width is set to 3 mm or more and 30 mm or less.

[0093] The length b of the connecting portion 22 in the left-right direction is preferably set to a predetermined value or less to prevent fingers or the like from entering through the intake / exhaust hole 13. Furthermore, from the viewpoint of heat dissipation efficiency, the length b is preferably set to a predetermined value or more. For example, the length b is set to be 1 mm or more and 30 mm or less.

[0094] The thickness t1 of the base 18 in the front-to-rear direction is preferably equal to or greater than a predetermined value from the viewpoint of ease of injection molding. Also, the thickness t1 is preferably equal to or less than a predetermined value from the viewpoint of weight and cost. For example, the thickness t1 is set to 0.5 mm or more and 4 mm or less.

[0095] The thickness t2 of the connecting portion 22 in the front-to-rear direction is preferably equal to or greater than a predetermined value from the viewpoint of ease of injection molding. Also, the thickness t2 is preferably equal to or less than a predetermined value from the viewpoint of weight and cost. For example, the thickness t2 is set to be equal to or greater than 0.5 mm and equal to or less than 4 mm.

[0096] The relationship between the thicknesses t1 and t2 is important for the weld line W to form in the portion other than the base 18 of the straight portion 16. That is, it is desirable to set the thicknesses t1 and t2 so that they are equal to or greater than 0.5 mm and equal to or less than 4 mm, respectively, and so that the above formulas (4) and (7) hold.

[0097] <6. Variations> A modified example of the configuration of the linear portion 16 and the connecting portion 22 that form the intake and exhaust hole 13 will be described. The straight portion 16 in this example is a straight portion 16C in which an inclined surface is formed on a part of the base portion 18. This will be specifically described with reference to FIG.

[0098] Fig. 19 shows one straight portion 16C and multiple connecting portions 22 extending in the left-right direction from the straight portion 16C. Fig. 19 also shows a cross-sectional view of the straight portion 16C and the connecting portions 22, and an end view of a portion where the connecting portions 22 are not located, taken along a plane H perpendicular to the up-down direction.

[0099] The straight portion 16C has a base portion 18C and protruding portions 19L and 19R. The base portion 18C is made up of a protruding portion 24 that is the rear portion and a base portion 25 that is the portion in front of the protruding portion 24.

[0100] The horizontal cross section of the protrusion 24 is rectangular, and the horizontal cross section of the base 25 is formed in an isosceles trapezoid shape and is wider in the left-right direction than the protrusion 24 .

[0101] The outer surfaces of the base portion 25 in the left-right direction are formed as inclined surfaces 26, 26 that approach each other as they approach the protruding portion 24.

[0102] By forming the inclined surface 26 on the straight portion 16C in this manner, the angle of the corner 27 where the rear surface of the base portion 25 and the inclined surface 26 are connected becomes larger than a right angle, making the corner 27 less likely to chip. Furthermore, when forming straight portion 16C and connecting portion 22 during the injection molding process, the cross-sectional area of ​​the space where the continuous portion between base portion 18C and protrusion 19 is formed is reduced. Specifically, width t4' of the base of protrusion 19 when inclined surface 26 is formed is made shorter than width t4 (= t2) of the base of protrusion 19 when inclined surface 26 is not formed. This makes it difficult for the molten resin PL to flow from base 18C of straight portion 16C into protruding portions 19L, 19R. That is, the time required for the molten resin PL to reach connecting portion 22 is lengthened, making it more likely that a weld line W will form in connecting portion 22. Furthermore, during the demolding process of injection molding, the molded product can be easily separated from the mold, improving work efficiency.

[0103] The inclined surface 26 is provided only in the part of the straight portion 16 that continues to the connecting portion 22 and in the part nearby, and is not formed in the part between adjacent connecting portions 22, 22, as shown in the end view of Figure 19.

[0104] In addition, the protrusions 19L and 19R have a wide portion 28 in the vicinity of the connecting portion 22 that is wider in the left-right direction, and other portions are formed as narrow portions 29 that are narrower in the left-right direction than the wide portion 28.

[0105] As a result, when the molten resin PL flows, for example, from above downward to form the straight portion 16C, the flow speed when forming the narrow portion 29 is slower than when the narrow portion 29 is not formed. Therefore, the time it takes for the molten resin PL to flow into the wide portion 28 that is the portion near the connecting portion 22 is lengthened, and the possibility of forming a weld line W in the connecting portion 22 can be increased.

[0106] As shown in FIG. 20, the edge of the intake / exhaust hole 13 at the connection portion 17 may be formed as a connecting portion 22. As a result, all of the intake and exhaust holes 13 are formed by a set of straight portions 16, 16 adjacent in the left-right direction and a set of connecting portions 22, 22 adjacent in the up-down direction. In other words, the various actions and effects described above and below also apply to the intake and exhaust holes 13' formed by the set of straight portions 16, 16, one end of the connecting portion 17 in the up-down direction, and the connecting portion 22.

[0107] In the above example, the display device 1 is provided with the rear cover 8 having the intake and exhaust holes 13 formed therein, but the intake and exhaust holes 13 may be formed in the rear cover or side cover of the outer casing of other electronic devices, etc. For example, in the case where a personal computer has an outer casing and various boards and devices such as a motherboard disposed in the internal space, the intake and exhaust holes 13 having the above-described characteristics may be formed in the rear or side of the outer casing.

[0108] Furthermore, the holes formed by the straight portions and connecting portions are not limited to intake and exhaust holes, and the present technology can be applied to various structures formed in a lattice pattern by injection molding in the display device 1. Note that, although the above example shows the case where the connecting portion 17 is formed on the outer periphery 15 of the rear cover 8, the present technology can also be applied to a configuration where the connecting portion 17 is not formed on the outer periphery 15.

[0109] <7. Summary> As described in the above examples, the rear cover 8 of the display device 1 has, when the three mutually perpendicular directions are defined as the first direction (up-down direction), the second direction (left-right direction), and the third direction (front-rear direction), respectively, a plurality of straight sections 16 (16A, 16B, 16C) extending in the first direction (up-down direction) and positioned spaced apart in the second direction (left-right direction), and a connecting section 22 connecting each part of two adjacent straight sections 16 (16A, 16B, 16C) in the second direction (left-right direction). In addition, the straight portions 16 (16A, 16B, 16C) and the connecting portion 22 are integrally formed by injection molding, and the straight portions 16 (16A, 16B, 16C) have a base 18 (18C) extending in a first direction (up-down direction) and a pair of protruding portions 19 (19L, 19R) protruding in a third direction (front-back direction) from both ends of the base 18 (18C) in a second direction (left-right direction), and the connecting portion 22 is continuous with each tip end 20 of the protruding portions 19 (19L, 19R) of the two straight portions 16 (16A, 16B, 16C) whose both ends are adjacent to each other. As a result, holes (intake and exhaust holes 13) are formed between the straight portions 16 (16A, 16B, 16C). Furthermore, during injection molding, the flow speed of the molten resin PL when forming the base portion 18 (18C) is made faster than the flow speed of the molten resin PL when forming the connecting portion 22. Therefore, a joining point (weld line W) of the molten resin PL diverged by the holes (intake and exhaust holes 13) is likely to be formed in the connecting portion 22. By forming the weld line W in the connecting portion 22, the strength of the base portion 18 (18C) can be improved. Furthermore, since the cross-sectional shape of the connecting portion between the straight portions 16 (16A, 16B, 16C) and the connecting portion 22 is a zigzag shape (bellows shape) made up of alternating U-shaped portions, tensile stress is unlikely to occur in the connecting portion 22 when an impact is applied to the base portion 18 (18C), and cracks or breaks are unlikely to occur in the connecting portion 22. Therefore, the number of back covers 8 that fall off during an impact test is reduced, and countermeasures are not required.

[0110] The effects described in this specification are merely examples and are not limiting, and other effects may also be present. Furthermore, the above examples can be combined in any way as long as the combination is not impossible.

[0111] <8. This Technology> This technology can also be configured as follows. (1) The three directions that are orthogonal to each other are defined as a first direction, a second direction, and a third direction, a plurality of linear portions extending in the first direction and spaced apart from each other in the second direction; a connecting portion connecting each part of two of the linear portions adjacent to each other in the second direction, the linear portion and the connecting portion are integrally formed by injection molding, the linear portion has a base portion extending in the first direction and a pair of protruding portions protruding in the third direction from both end portions of the base portion in the second direction, The connecting portion has both ends connected to the tip ends of the protruding portions of the two adjacent linear portions. Display device. (2) The connecting portions are provided in plurality and spaced apart from each other in the first direction. The display device according to (1) above. (3) a pitch width a between the adjacent connecting portions in the first direction, a length b of the connecting portions in the second direction, a thickness t1 of the base portion in the third direction, and a thickness t2 of the connecting portions in the third direction satisfy the following formula: The display device according to (2) above. (t1 / t2) 3 >a / b (4) The pitch width a is made larger than the length b. The display device according to (3) above. (5) The thickness t1 is greater than the thickness t2. The display device according to any one of (3) to (4) above. (6) The thickness t1 is greater than the thickness t3 of the protrusion in the second direction. The display device according to any one of (3) to (5) above. (7) The thickness t2 and the thickness t3 are set to the same thickness. The display device according to (6) above. (8) At least a portion of outer surfaces of the straight portion on both sides in the second direction is formed as an inclined surface approaching each other in the second direction as it moves away from the connecting portion in the third direction. The display device according to any one of (1) to (7) above. (9) A rear cover is provided behind the display panel, The linear portion and the connecting portion are provided on the rear cover. The display device according to any one of (1) to (8) above. (10) The base portion is located on the outer surface side of the connecting portion. The display device according to (9) above. (11) A space surrounded by the adjacent linear portions and the adjacent connecting portions in the first direction is formed as an intake / exhaust hole. The display device according to any one of (3) to (7) above. [Explanation of symbols]

[0112] 1 Display device 8 Rear cover 13, 13' intake and exhaust holes 16, 16A, 16B, 16C Straight section 18, 18C base 19, 19L, 19R protrusion 20 Tip 21 Exterior 22 Connecting part 26 Slope a Pitch width b Length t1, t2, t3 thickness

Claims

1. A display panel; an outer casing that surrounds the rear, side, and front peripheral edge of the display panel; the outer casing has a rear cover facing the rear surface of the display panel, The rear cover is a plurality of linear portions extending in a first direction parallel to the display panel and spaced apart from each other; a plurality of connecting portions extending to connect adjacent ones of the plurality of straight line portions, The connecting portion is located at a position deeper than the rear surface of the adjacent linear portion relative to the display panel. Display device.

2. The straight portion and the connecting portion are integrally formed by injection molding. The display device according to claim 1 .

3. the rear cover has two outer peripheral portions extending in the first direction and spaced apart from each other in the second direction; the two outer circumferential portions are arranged to sandwich the plurality of linear portions from the second direction, The second direction is perpendicular to the first direction and, together with the first direction, forms a plane parallel to the front surface of the display panel. The display device according to claim 1 .

4. The plurality of connecting portions each connect a pair of adjacent straight portions. The display device according to claim 1 .

5. The straight portion has a base extending in the first direction, a pitch width a in the first direction, a thickness t2, a length b in the second direction of the connecting portion located between a pair of adjacent linear portions, and a thickness t1 of the base portion satisfy the following formula, The second direction is perpendicular to the first direction and, together with the first direction, forms a plane parallel to the front surface of the display panel. The display device according to claim 4 . (t1 / t2) 3 > a / b

6. The pitch width a is larger than the length b. The display device according to claim 5 .

7. The thickness t1 is greater than the thickness t2. The display device according to claim 5 .

8. The adjacent straight portions each have a rectangular recess formed on the front side, the recesses in the adjacent linear portions are formed by opposing wall-like protrusions, The protrusion has a thickness t3 The display device according to claim 5 .

9. The thickness t1 is greater than the thickness t3 of the protrusion in the second direction. The display device according to claim 8 .

10. The thickness t2 and the thickness t3 are set to the same thickness. The display device according to claim 8 .

11. A space surrounded by the adjacent linear portions and the adjacent connecting portions in the first direction is formed as an intake / exhaust hole. The display device according to claim 1 .

12. the rear cover includes a series of first exhaust holes; the series of first exhaust holes is formed as a plurality of holes; Each of the plurality of holes is a hole surrounded by the linear portion and the connecting portion. The display device according to claim 1 .

13. A bezel is provided in front of the rear cover and surrounds the display panel. The display device according to claim 1 .

14. A second exhaust hole is formed in the bezel. The display device according to claim 13.

15. Equipped with a heat-generating electronic board, the electronic board is disposed between the display panel and the rear cover, The heat is discharged from the first exhaust hole. The display device according to claim 12.

16. the rear cover includes a series of first exhaust holes; Equipped with a heat-generating electronic board, the electronic board is disposed between the display panel and the rear cover, the heat is exhausted from the first exhaust hole and the second exhaust hole, the series of first exhaust holes is formed as a plurality of holes; Each of the plurality of holes is a hole surrounded by the linear portion and the connecting portion. The display device according to claim 14.

17. Each of the adjacent straight portions has a rectangular recess formed on the front side, the recesses in the adjacent linear portions are formed by opposing wall-like protrusions, The corners of the protrusions are rounded. The display device according to claim 1 .

18. The second exhaust holes are formed in an elongated shape and divided into at least two groups, Each of the groups has a plurality of the second exhaust holes that are parallel to each other. The display device according to claim 14.

19. The rear cover is formed from molten resin. The display device according to claim 1 .

20. The bezel is formed in a continuous frame shape. The display device according to claim 13.

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