Indicating device

Abstract

This display device comprises: a plurality of linear parts which, with three directions that are orthogonal to one another being defined as a first direction, a second direction, and a third direction, are positioned to extend in the first direction and be separated from each other in the second direction; and a connecting part that connects two of the linear parts adjacent to each other in the second direction. The linear parts and the connecting part are integrally formed by injection molding, and the linear parts include: a base part extending in the first direction; and a pair of protruding parts protruding in the third direction from both ends of the base part which are in the second direction. The connecting part is connected, at both ends thereof, to each leading end of the protruding parts of the two adjacent linear parts.

Description

Technical Field

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

Background Art

[0002] Some display devices typified by televisions have a structure formed by injection molding. In such a display device, for example, a back cover that is part of the outer casing may be formed by injection molding. A plurality of holes for sucking and exhausting air are formed in the back cover to cool the heat generated inside the outer casing (see, for example, Patent Document 1). The portion having such a plurality of holes is formed in a lattice pattern.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, when a lattice-shaped portion is formed by injection molding, the flow division and confluence of the molten resin occur. A weld line may be formed at the confluence point of the molten resin. Since the portion where the weld line is formed has lower strength than other portions, the occurrence of the weld line causes cracks and defects. For example, if cracks and defects occur in the impact test of the product, countermeasures are required.

[0005] The present technology has been made in view of such problems, and an object thereof is to improve the strength of the portion where the holes are formed.

Means for Solving the Problems

[0006] In the display device according to the present technology, three mutually orthogonal directions are defined as the first direction, the second direction, and the third direction, respectively. The display device includes a plurality of linear portions extending in the first direction and spaced apart in the second direction, and connecting portions connecting a part of each of two adjacent linear portions in the second direction. The linear portions and the connecting portions 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 end portions continuous with the tip end portions of the protruding portions of the two adjacent linear portions. Thereby, holes are formed between the linear portions. Also, the flow rate of the molten resin when forming the base portion during injection molding is made faster than the flow rate of the molten resin when forming the connecting portion. Therefore, the confluence point (weld line) of the molten resin diverted by the holes is likely to be formed in the connecting portion.

[0007] In the above-described display device, a plurality of the connecting portions may be provided at intervals in the first direction. Thereby, the strength of the linear portion can be improved.

[0008] In the above-described display device, the pitch width a between the adjacent connecting portions in the first direction, the length b of the connecting portion in the second direction, the thickness t1 of the base portion in the third direction, and the thickness t2 of the connecting portion in the third direction may satisfy the following formula. (t1 / t2) 3 >a / b Thereby, a weld line is likely to be formed in the connecting portion.

[0009] In the above-described display device, the pitch width a may be made larger than the length b. Thereby, 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 made larger than the thickness t2. As a result, the flow rate of the molten resin when forming the connecting portion is made slower than the flow rate of the molten resin when forming the base portion of the straight portion.

[0011] In the above-described display device, the thickness t1 may be made larger than the thickness t3 of the protruding portion in the second direction. As a result, the flow rate of the molten resin when forming the protruding portion is made slower than the flow rate of the molten resin when forming the base portion of the straight portion.

[0012] In the above-described display device, the thickness t2 and the thickness t3 may be made the same thickness. As a result, the thickness of either the connecting portion or the protruding portion does not have to be made excessively thin.

[0013] In the above-described display device, at least a part of the 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. As a result, the cross-sectional area of the space in which the continuous portion of the base portion and the protruding portion in the mold used for injection molding is formed is made small, and it is made difficult for the molten resin to flow into the protruding portion.

[0014] In the above-described display device, a back cover disposed behind the display panel is provided. The straight portion and the connecting portion may be provided on the back cover. As a result, a weld line is likely to be formed at the connecting portion on the back 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 be formed is located closer to the internal space of the display device than the base portion.

[0016] In the above-described display device, a space surrounded by the adjacent straight portions and the adjacent connecting portions in the first direction may be formed as an intake and exhaust hole. As a result, it becomes possible to exhaust heat generated from an electronic substrate or the like through the intake and exhaust holes, and the strength of the structure forming the intake and exhaust holes can be maintained at a certain level or higher.

Brief Description of the Drawings

[0017]

Figure 1

Figure 2

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Figure 8

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Figure 12

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Mode for Carrying Out the Invention

[0018] Hereinafter, the embodiments will be described in the following order. <1. Configuration of the display device> <2. Structure of the back cover> <3. Molding process of the back cover in injection molding> <4. Regarding the pressure loss of the molten resin> <5. Dimensional examples> <6. Modified examples> <7. Summary> <8. This technology>

[0019] <1. Configuration of the display device> The configuration of the display device 1 of this technology will be described with reference to FIGS. 1 and 2. Note that the display device 1 is, for example, a device such as a television device or a monitor device on which video or an image is displayed.

[0020] The display device 1 includes a display unit 2 having a substantially rectangular shape, a support unit 3 attached to the rear surface portion of the display unit 2 and extending in the vertical direction, and a base unit 4 attached to the lower end portion of the support unit 3 and having a flat shape in the horizontal direction to stabilize the postures of the display unit 2 and the support unit 3.

[0021] In the following description, the front-rear direction will be described with the user side viewing the video (image) projected on the display device 1 as the front. Also, there may be cases where the gravitational direction is described as the vertical direction and the horizontal direction is described as the left-right direction. Note that for the left-right direction, the direction seen from the back side of the display device 1 is used.

[0022] Note that the "first direction", "second direction", and "third direction" referred to in the claims are respectively the vertical direction, horizontal direction, and front-rear direction described above. However, these directions are according to the opening direction of the intake and exhaust holes described later. Specifically, since the intake and exhaust holes described in this embodiment are holes that open backward, the first direction is the vertical direction. For example, when the intake and exhaust holes are holes that open downward, the first direction is the front-rear direction, the second direction is the horizontal direction, and the third direction is the vertical direction. Note that these directions are for convenience of explanation only and are not limited to these directions regarding the implementation of the present technology.

[0023] The display unit 2 includes an outer casing portion 5 having an opening portion that is open forward and houses various parts such as an electronic circuit for displaying images and the like inside, and a display panel 6 that is arranged so that images and the like are displayed and can be seen from the front through the opening portion of the outer casing portion 5.

[0024] The outer casing portion 5 is composed of, for example, a bezel 7 formed as a front-side portion, a back cover 8 formed as a rear-side portion and located behind the display panel 6, and various operating elements (not shown).

[0025] The bezel 7 includes an upper surface portion 9 that faces the vertical direction and extends in the horizontal direction, a pair of side surface portions 10, 10 that face the horizontal direction and are continuous with both left and right end portions of the upper surface portion 9 and extend in the vertical direction, a lower surface portion 11 that faces the vertical direction and both left and right end portions are continuous with the lower end portions of the pair of side surface portions 10, 10, and a frame-shaped portion 12 formed in a frame shape that faces the front and rear. The outer peripheral portion of the frame-shaped portion 12 is continuous with the front end portions of the upper surface portion 9, the side surface portions 10, 10, and the lower surface portion 11.

[0026] The back cover 8 is a resin member formed in a plate shape that faces the front and rear by injection molding, and is attached to the rear end portion of the bezel 7 from the rear. The back cover 8 is provided with air intake holes for taking air into the internal space and exhaust holes for discharging air from the internal space. Heat discharged from a substrate or the like disposed inside the display unit 2 is cooled by these air intake holes and exhaust holes. These air intake holes and exhaust holes will be collectively described as intake / exhaust holes 13.

[0027] A plurality of intake / exhaust holes 13 are provided in the back cover 8 as holes that open rearward, downward, upward, or laterally. Alternatively, not only those opening in these directions but also intake / exhaust holes 13 opening in an oblique direction may be used. The portion where a plurality of intake / exhaust holes 13 are formed is provided in a lattice shape. Note that the intake / exhaust holes 13 may be provided in the bezel 7. For example, the intake / exhaust holes 13 shown in FIG. 2 illustrate a hole formed to open rearward in the back cover 8 and a hole formed to open downward in the lower surface portion 11 of the bezel 7. In the following description, the intake / exhaust holes 13 opening rearward of the back cover 8 will be described. Although various shapes of the plurality of intake / exhaust holes 13 are conceivable, in this example, the intake / exhaust holes 13 having an elongated shape in the vertical direction will be taken as an example.

[0028] The display panel 6 has a laminated structure including a diffusion plate, an optical sheet, a wiring layer, and the like.

[0029] <2. Structure of the Back Cover> The specific configuration of the back cover 8 will be described with reference to FIG. 3.

[0030] The back cover 8 is composed of a central portion 14 where a plurality of intake / exhaust holes 13 are formed and an outer peripheral portion 15 which is the other portion with a predetermined portion.

[0031] The portion of the outer peripheral portion 15 excluding the outermost edge portion 15a includes a plurality of straight portions 16 extending in the vertical direction and spaced apart in the horizontal direction, and connection portions 17 located between the straight portions 16. A recess opening rearward is 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. 4.

[0033] The straight portion 16 includes a base portion 18 that extends in the vertical direction and has a substantially rectangular parallelepiped shape, and a pair of projecting portions 19, 19 that project forward from both left and right end portions of the base portion 18 and extend in the vertical direction and have a substantially rectangular parallelepiped shape. Here, the projecting portion 19 that projects from the left end portion of the base portion 18 is described as the projecting portion 19L, and the projecting portion 19 that projects from the right end portion is described as the projecting portion 19R. When the left and right projecting portions are not distinguished, they are simply described as the projecting portion 19.

[0034] The connecting portion 17 is continuously connected to the tip portions 20 of the projecting portions 19L of the straight portion 16 and the tip portions 20 of the projecting portions 19R of the straight portion 16 where both left and right end portions are adjacent to the tip portions 20 of the projecting portions 19R of the straight portion 16, respectively.

[0035] The rear surface of the base portion 18 is formed as a part of the outer surface 21 of the display device 1. The outer surface 21 is subjected to, for example, surface treatment to make it smooth by eliminating irregularities or embossing treatment to form irregularities. Further, the outer surface 21 is also a portion where an impact is applied in the impact test. Furthermore, the outer surface 21 is one of the portions where an impact is likely to be applied by a user or the like after the product is commercialized.

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

[0037] Therefore, the impact applied to the rear cover 8 is absorbed by distortion before being transmitted to the connecting portion 17 and the projecting portion 19, so that a large stress does not occur in the connecting portion 17 and the projecting portion 19.

[0038] Next, the central portion 14 of the rear cover 8 will be described with reference to FIGS. 3, 6, and 7.

[0039] The central portion 14 of the back cover 8 includes a plurality of straight portions 16 provided at intervals in the left - right direction and a plurality of connecting portions 22 provided at intervals in the up - down direction. That is, a plurality of connecting portions 22 are provided between two adjacent straight portions 16, 16, and the strength of the straight portion 16 is improved.

[0040] As shown in FIG. 7, the connecting portion 22 has the same shape as the connecting portion 17 in a horizontal cross - section. That is, the connecting portion 22 has a rectangular parallelepiped shape extending in the left - right direction, and both left and right end portions are continuously connected to the tip portion 20 of the protruding portion 19R of the straight portion 16 and the tip portion 20 of the protruding portion 19L of the adjacent straight portion 16, respectively. The plurality of connecting portions 22 are provided at intervals in the up - down direction.

[0041] The space surrounded by the adjacent straight portions 16, 16 in the left - right direction and the adjacent connecting portions 22, 22 in the up - down direction is formed as the intake and exhaust holes 13. The heat generated from an electronic substrate or the like disposed inside the outer housing portion 5 can be released to the outside through the intake and exhaust holes 13. Therefore, good heat dissipation performance in the display device 1 can be ensured. In addition, the space surrounded by the adjacent straight portions 16, 16 in the left - right direction, the end portion of the connecting portion 17, and the connecting portion 22 is also used as the intake and exhaust holes 13.

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

[0043] In the present embodiment, for example, the thickness t1 is larger than the thickness t2 and the thickness t3. Also, the thickness t2 and the thickness t3 are of the same size. Furthermore, the pitch width a is larger than the length b. Incidentally, the conditions that these thicknesses and lengths should satisfy will be described later again.

[0044] <3. Molding Process of Rear Cover 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 the molten resin PL has flowed in from the inflow position E to form the illustrated portion in the rear cover 8. The inflow position E is, for example, the portion closest to the distance from a gate (not shown) in the portion shown in FIG. 8. Note that the inflow position E shown in FIG. 8 is merely an example and can be arbitrarily set according to the position of the gate provided in the rear cover 8. Also, the number of inflow positions E does not have to be one, and a plurality of them may be provided. Note that the position of the gate when forming the rear cover 8 by injection molding may be provided at any location. Also, the number of gates may be one or a plurality.

[0046] In each of the subsequent figures, the positional relationship between the rear cover 8, which is the final molded product, and the molten resin PL (the textured portion in the figure) at that time is shown. Also, the flow state of the molten resin in the internal space (cavity) of the mold cut by the dashed-dotted line F-F shown in FIG. 8 and the like will be described.

[0047] As shown in FIGS. 8 and 9, the molten resin PL first flows 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 portion 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 portion 18 is formed. As a result, there is a state where the molten resin is flowing into the base portion 18 and the molten resin is not flowing into the protruding portion 19. Therefore, the time until the molten resin PL reaches the space forming the connecting portion 22 can be delayed, and the weld line W can be easily formed at the connecting portion 22.

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

[0050] Subsequently, as shown in FIGS. 12 and 13, the molten resin PL flows from the space forming the straight portion 16A toward 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] Subsequently, as shown in FIGS. 14 and 15, the molten resin PL merges in the space forming the connecting portion 22. Therefore, the weld line W of the molten resin PL is formed in the space forming the connecting portion 22.

[0052] As described above, the thickness t1 of the base portion 18 in the front-rear direction is made larger than the thickness t2 of the connecting portion 22 in the front-rear direction. 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 portion 18 (see FIGS. 12 and 14). Therefore, the weld line W can be easily formed at the connecting portion 22.

[0053] Note that 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 confluence point of the molten resin PL at the connecting portion 22, it is conceivable 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 where the thickness is reduced will decrease, and breakage or cracking is likely to occur. By making the thickness t2 of the connecting portion 22 and the thickness t3 of the protruding portion 19 the same, the connecting portion 22 and the protruding portion 19 can have a certain thickness as compared with the case where only one of the thicknesses t2 and t3 is reduced. Therefore, while ensuring the strength of the protruding portion 19 and the connecting portion 22, the flow rate of the molten resin PL when forming the protruding portion 19 and the connecting portion 22 can be slowed down, and the durability of the back cover 8 can be improved.

[0054] Note that, as shown in each figure, the base portion 18 is located on the outer surface side (rearward) of the connecting portion 22. As a result, the connecting portion 22 where the weld line W is likely to be formed is located closer to the internal space side of the display device 1 than the straight portion 16. Therefore, since it is difficult for an impact to be applied to the connecting portion 22 where the weld line W is likely to be formed, breakage or cracking due to the weld line W is less likely to occur, and the durability of the back cover 8 can be improved. Also, when the base portion 18 is the outer surface 21 of the display device 1, an impact may be applied to the base portion 18 in the impact test. In such a case, since the weld line W is not formed on the base portion 18, it is easy to pass the impact test and no countermeasures are required. Therefore, the occurrence of unnecessary man-hours can be suppressed.

[0055] <4. Regarding the pressure loss of the molten resin> The flow rate of the molten resin PL during injection molding is determined according to the magnitude of the pressure loss generated when the molten resin PL flows inside the mold. Specifically, the greater the pressure loss, the lower the flow rate. The pressure loss ΔP is calculated by the following formula (1).

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

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

[0058] The following describes a specific example of the pressure loss regarding the back cover 8, using the vertical pitch width a of a plurality of connecting portions 22 spaced apart vertically and the length b of the connecting portion 22 in the horizontal direction.

[0059] In order for the weld line W to be formed outside the straight portion 16, it is required that the molten resin PL that has formed the straight portion 16 (the straight portion 16A in FIG. 9) finishes flowing through the adjacent straight portion 16 (the straight portion 16B in FIG. 9) before the molten resin PL that forms the connecting portion 22 finishes forming the connecting portion 22.

[0060] To satisfy this condition, the time required to form the base portion 18 of the straight portion 16 over the pitch width a needs to 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 forming the base portion 18 of the straight portion 16 over the pitch width a can be expressed by the following equation (2) (see FIG. 16).

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

[0063] Also, 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 equation (3) (see FIG. 16).

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

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

[0066] (t1 / t2) 3 >a / b ··· Formula (4)

[0067] By satisfying the above formula (4), during injection molding, before the molten resin PL forming the base portion 18 forms the entire connecting portion 22, the molten resin PL flows from the base portion 18 of the adjacent straight portions 16 into the connecting portion 22. Therefore, since the weld line W is not formed in the straight portion 16, 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 formula (4) are conceivable. However, the value of the variable t1 is the thickness in the front - rear direction of the base portion 18, and it is naturally determined by the design considering the strength and weight of the back cover 8. Also, the value of the variable a is the vertical pitch width of the connecting portions 22, 22, and it is naturally determined considering the size of the intake and exhaust holes 13. Further, the value of the variable b is the length in the left - right direction of the connecting portion 22, and it is naturally determined considering the size of the intake and exhaust holes 13.

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

[0070] In order to form the weld line W in the connecting portion 22, it is necessary for the variable t2 to be less than a predetermined value to satisfy formula (4). On the other hand, considering the durability of the back cover 8, etc., the thickness t2 in the front - rear direction of the connecting portion 22 cannot be made excessively small, and it is desirable for the variable t2 to be as large as possible.

[0071] Therefore, the conditions for increasing the value of the thickness t2 will be described below. In the display device 1, it is most desirable that the weld line W is formed in the connecting portion 22 to ensure the high strength of the back cover 8. However, it is also allowed that the weld line W is formed in the protruding portion 19 or the connecting portion 22, which is a portion other than the base portion 18. Even when the weld line W is formed in the protruding portion 19, it is possible to ensure sufficient strength of the back cover 8. By relaxing the formula (4), which is the condition for forming the weld line W in the protruding portion 19, to the condition for forming the weld line W in the protruding portion 19 or the connecting portion 22, the value of the variable t2 can be increased as follows.

[0072] In order to form the weld line W in the protruding portion 19 or the connecting portion 22, it is only necessary that the total value of the pressure loss of the molten resin PL when forming the protruding portion 19 of the straight portion 16 and the pressure loss ΔP2 of the molten resin PL when forming the connecting portion 22 is larger than the pressure loss ΔP1.

[0073] That is, as shown in FIG. 17, when the path through which the molten resin PL flows from the space forming the protruding portion 19R of the straight portion 16A, through the space forming the connecting portion 22, and into the space forming the protruding portion 19L of the straight portion 16B is defined as the path G, it is only necessary that the pressure loss ΔP3 of the molten resin PL flowing through the path G is larger than the pressure loss ΔP1.

[0074] Here, if only either the thickness t2 in the front-rear direction of the connecting portion 22 or the thickness t3 in the left-right direction of the protruding portion 19 is reduced, the strength of the portion with the reduced thickness may be reduced too much. Therefore, it is desirable that the thickness t2 in the front-rear direction of the connecting portion 22 and the thickness t3 in the left-right direction of the protruding portion 19 have the same thickness. The pressure loss ΔP3 when the thickness t2 and the thickness t3 have the same value is expressed by the following formula.

[0075] ΔP3 = 12μb’Q / (w×t2 3 ) ··· Formula (5)

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

[0077] b’ = 2c - t2 + b + t3 = 2c - t2 + b + t2 = 2c + b ··· Equation (6)

[0078] For the weld line W to be formed on the portion of the path G, that is, on the protrusion 19 or the connecting portion 22, since the pressure loss ΔP3 only needs to be greater than the pressure loss ΔP1, the following Equation (7) can be derived from Equation (2), Equation (5), and Equation (6).

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

[0080] From Equation (4) and Equation (7), the possible range of values that the thickness t2 can take is expanded 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) shows that (t1 / t2) can be a smaller value for Equation (4). Therefore, according to Equation (7), it is possible to make t2 a larger value than in Equation (4).

[0082] By determining the thickness t2 based on Equation (7), the thickness t2 of the protrusion 19 and the connecting portion 22 can be made thicker, so the strength of the protrusion 19 and the connecting portion 22 can be improved. Also, during injection molding, when forming the base 18 of the straight portion 16A, the molten resin PL flows from the base 18 of the adjacent straight portion 16B to the protrusion 19L of the adjacent straight portion 16B after forming the protrusion 19R and the connecting portion 22 and before forming the protrusion 19L of the adjacent straight portion 16B. That is, in the cavity of the mold, the molten resin PL flowing from the spaces for forming the adjacent straight portions 16 to the space for forming the connecting portion 22 located therebetween merges at the connecting portion 22 or the protrusion 19. Therefore, since the weld line W is not formed on the straight portion 16, the strength of the straight portion 16 can be further improved.

[0083] Note that, by making the pitch width a of the connecting portion 22 larger than the length b of the connecting portion 22, a space surrounded by the straight portion 16 and the connecting portion 22 is formed as the elongated intake / exhaust hole 13. Therefore, it is possible to suppress the intrusion of fingers, foreign objects, etc. from the elongated intake / exhaust hole 13 into the interior of the display device 1.

[0084] Here, although it has been explained that the condition of the thickness t2 can be relaxed by setting variables other than the thickness t2 as constants, if the combination of variables to be set as constants is changed, the conditions of variables other than the thickness t2 can be relaxed.

[0085] <5. Dimension Example> Examples of the dimensions of each part of the straight portion 16 and the connecting portion 22 are shown in FIG. 18. The left and right end portions at the rear end of the base portion 18 are each formed as a corner portion 18a. Also, the inner end portions of the tip portions 20, 20 of the protruding portions 19L, 19R are each formed as an inner corner portion 20a, 20a.

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

[0087] In view of 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. Thereby, the speed of the molten resin when forming the protruding portion 19 and the connecting portion 22 is made sufficiently slower than the speed of the molten resin PL when forming the base portion 18, and it becomes easier to form the weld line W in a portion other than the base portion 18.

[0088] It is desirable that chamfering is performed on the corner portion 18a and the inner corner portion 20a to prevent chipping and the like. For the corner portion 18a, for example, chamfering with a radius of 0.5 mm to 1 mm is preferably performed, and for the inner corner portion 20a, for example, chamfering with a radius of 0.3 mm is preferably performed.

[0089] Note that the corner portions at both ends in the rear end portion of the connecting portion 22 are 180 degrees or more, and since chipping and the like are unlikely to occur, there is no need to perform chamfering. Similarly, since the corner portion provided at the continuous portion of the base portion 18 and the protruding portion 19 is also 180 degrees or more, there is no need to perform chamfering.

[0090] Furthermore, in order to easily perform the step of separating the back cover 8 as a molded product from the mold, it is desirable that the angle r formed by the direction in which the protruding portion 19 extends and the front-rear direction is greater than 0 degrees. The angle r is, for example, 0.5 degrees or more.

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

[0092] The maximum value of the pitch width a in the vertical direction of the connecting portion 22 is desirably set to a predetermined value or less so that the strength of the straight portion 16 does not decrease. Also, from the viewpoint of exhaust heat efficiency, the pitch width a is desirably 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 in the left-right direction of the connecting portion 22 is desirably set to a predetermined value or less in order to prevent the intrusion of fingers or the like from the intake and exhaust holes 13. Also, from the viewpoint of exhaust heat efficiency, the length b is desirably set to a predetermined value or more. For example, the length b is set to 1 mm or more and 30 mm or less.

[0094] The thickness t1 in the front-rear direction of the base portion 18 is desirably set to a predetermined value or more from the viewpoint of ease of injection molding. Also, the thickness t1 is desirably set to a predetermined value or less from the viewpoints 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-rear direction is desirably set to be equal to or greater than a predetermined value from the viewpoint of ease of injection molding. Further, the thickness t2 is desirably set to be equal to or less than a predetermined position from the viewpoints of weight and cost. For example, the thickness t2 is set to be 0.5 mm or more and 4 mm or less.

[0096] In order for a weld line W to be formed in a portion other than the base portion 18 of the straight portion 16, the relationship between the thicknesses t1 and t2 is important. That is, it is desirable that the above equations (4) and (7) are satisfied while each of the thickness t1 and the thickness t2 satisfies the condition of being 0.5 mm or more and 4 mm or less.

[0097] <6. Modification example> A modification example of the configuration of the straight portion 16 and the connecting portion 22 that form the intake and exhaust holes 13 will be described. The straight portion 16 in this example is a straight portion 16C in which an inclined surface is formed in a part of the base portion 18. Specifically, it will be described with reference to FIG. 19.

[0098] FIG. 19 shows one straight portion 16C and a plurality of connecting portions 22 extending in the left-right direction from the straight portion 16C. Further, FIG. 19 shows a cross-sectional view of the straight portion 16C and the connecting portion 22, and an end view in a plane H orthogonal to the vertical direction as an end view of a portion where the connecting portion 22 is not located.

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

[0100] The protruding portion 24 has a rectangular horizontal cross-sectional shape, and the base portion 25 has a trapezoidal horizontal cross-sectional shape and is wider in the left-right direction than the protruding portion 24.

[0101] The outer surfaces of the base portion 25 in the left-right direction are formed as inclined surfaces 26 and 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 way, the angle of the corner portion 27 of the portion where the rear surface of the base portion 25 and the inclined surface 26 are continuous is made larger than a right angle, and the corner portion 27 is made less likely to chip. Further, when forming the connecting portion 22 with the straight portion 16C in the process of injection molding, the cross-sectional area of the space where the continuous portion of the base portion 18C and the protruding portion 19 is formed is made smaller. Specifically, the width t4' of the base of the protruding portion 19 when the inclined surface 26 is formed is shorter than the width t4 (= t2) of the base of the protruding portion 19 when the inclined surface 26 is not formed. As a result, it becomes difficult for the molten resin PL to flow from the base portion 18C of the straight portion 16C into the protruding portions 19L and 19R. That is, the time required for the molten resin PL to reach the connecting portion 22 is lengthened, and the weld line W is more likely to be formed at the connecting portion 22. Further, in the mold release process of injection molding, it is possible to easily separate the molded product and the mold, and the working efficiency can be improved.

[0103] The inclined surface 26 is provided only in the portion of the straight portion 16 that is continuous with the connecting portion 22 and the vicinity thereof, and is not formed in the portion between the adjacent connecting portions 22, 22 as shown in the end view of FIG. 19.

[0104] Further, the protruding portions 19L and 19R are formed such that the portion near the connecting portion 22 is a wide portion 28 having a wide width in the left-right direction, and the other portions are narrow portions 29 having a narrower width in the left-right direction than the wide portion 28.

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

[0106] Note that, as shown in FIG. 20, in the connection part 17, the edge part of the intake / exhaust hole 13 may be formed as the connection part 22. Thus, all the intake / exhaust holes 13 are formed by a set of straight parts 16, 16 adjacent to each other in the left-right direction and a set of connection parts 22, 22 adjacent to each other in the up-down direction. That is, regarding the intake / exhaust hole 13' formed by a set of straight parts 16, 16, one end part in the up-down direction of the connection part 17, and the connection part 22, the various actions and effects described above and below will apply.

[0107] In the above-described example, an example in which the display device 1 includes the back cover 8 in which the intake / exhaust holes 13 are formed has been described. However, the intake / exhaust holes 13 may be formed in the back cover, side cover, etc. of the outer casing of other electronic devices or the like. For example, when a personal computer is provided with various substrates and devices such as a motherboard arranged in the internal space and an outer casing, the intake / exhaust holes 13 having the above-described features may be formed on the back surface or side surface of the outer casing.

[0108] Moreover, the holes formed by the straight part and the connection part are not limited to the intake / exhaust holes, and the present technology can be applied to various structures formed in a lattice shape by injection molding in the display device 1. In the above, an example in which the connection part 17 is formed in the outer peripheral part 15 of the back cover 8 has been shown. However, the present technology can also be applied to a configuration in which the connection part 17 is not formed in the outer peripheral part 15.

[0109] <7. Summary> As described in each of the above examples, when the three directions orthogonal to each other of the back cover 8 of the display device 1 are the first direction (up-down direction), the second direction (left-right direction), and the third direction (front-back direction), respectively, a plurality of straight parts 16 (16A, 16B, 16C) extending in the first direction (up-down direction) and spaced apart in the second direction (left-right direction), and a connection part 22 connecting a part of each of two adjacent straight parts 16 (16A, 16B, 16C) in the second direction (left-right direction). Further, the straight portions 16 (16A, 16B, 16C) and the connecting portion 22 are integrally formed by injection molding. The straight portion 16 (16A, 16B, 16C) has a base portion 18 (18C) extending in the first direction (vertical direction), and a pair of protruding portions 19 (19L, 19R) protruding in the third direction (front-rear direction) from both end portions of the base portion 18 (18C) in the second direction (left-right direction). The connecting portion 22 is continuous with the tip portions 20 of the protruding portions 19 (19L, 19R) of two straight portions 16 (16A, 16B, 16C) whose both end portions are adjacent to each other. Thereby, a hole (suction / exhaust hole 13) is formed between the straight portions 16 (16A, 16B, 16C). Also, the flow rate of the molten resin PL when forming the base portion 18 (18C) during injection molding is made faster than the flow rate of the molten resin PL when forming the connecting portion 22. Therefore, the confluence point (weld line W) of the molten resin PL diverted by the hole (suction / exhaust hole 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. In addition, since the cross-sectional shape at the continuous portion of the straight portion 16 (16A, 16B, 16C) and the connecting portion 22 is a zigzag shape (bellows shape) in which U-shaped portions are alternately combined, tensile stress is unlikely to be generated in the connecting portion 22 when an impact is applied to the base portion 18 (18C), and cracks and breakage are unlikely to occur in the connecting portion 22. Therefore, the back cover 8 that drops off due to the impact test is reduced and no countermeasure is required.

[0110] Note that the effects described in this specification are merely examples and are not limited, and there may be other effects. Also, each of the above examples can be combined in any way as long as the combination is possible.

[0111] <8. The present technology> The present technology can also adopt the following configuration. (1) Three directions orthogonal to each other are defined as the first direction, the second direction, and the third direction, respectively. A plurality of straight portions extending in the first direction and spaced apart in the second direction, and a connecting portion connecting a part of each of two adjacent straight portions in the second direction, wherein the straight portion and the connecting portion are integrally formed by injection molding, the straight 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, both end portions of the connecting portion are continuous with the tip end portions of the protruding portions in the two adjacent straight portions, A display device. (2) A plurality of the connecting portions are provided at intervals in the first direction, The display device according to (1) above. (3) The pitch width a between the adjacent connecting portions in the first direction, the length b of the connecting portion in the second direction, the thickness t1 of the base portion in the third direction, and the thickness t2 of the connecting portion 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 made larger than the thickness t2, The display device according to any one of (3) to (4) above. (6) The thickness t1 is made larger than the thickness t3 of the protruding portion 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 made the same thickness, The display device according to (6) above. (8) The outer surfaces on both sides of the straight portion in the second direction are formed as inclined surfaces that at least partially approach each other in the second direction as they move away from the connecting portion in the third direction. The display device according to any one of (1) to (7) above. (9) Comprising a back cover disposed behind the display panel, The straight portion and the connecting portion are provided on the back 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 straight portions and the adjacent connecting portions in the first direction is formed as an intake and exhaust hole The display device according to any one of (3) to (7) above.

Explanation of Signs

[0112] 1 Display device 8 Back cover 13, 13’ Intake and exhaust hole 16, 16A, 16B, 16C Straight portion 18, 18C Base portion 19, 19L, 19R Protrusion 20 Tip portion 21 Outer surface 22 Connecting portion 26 Inclined surface a Pitch width b Length t1, t2, t3 Thickness

Claims

1. Three directions orthogonal to each other are defined as the first direction, the second direction, and the third direction, respectively. A plurality of straight portions extending in the first direction and spaced apart in the second direction. A connecting portion connecting a part of each of two adjacent straight portions in the second direction. The straight portion and the connecting portion are integrally formed by injection molding. The straight 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. Both ends of the connecting portion are continuous with the tip ends of the protruding portions of the two adjacent straight portions, and a plurality of them are provided at intervals in the first direction. The pitch width a between adjacent connecting portions in the first direction, the length b of the connecting portion in the second direction, the thickness t1 of the base portion in the third direction, and the thickness t2 of the connecting portion in the third direction satisfy the following formula. The pitch width a is larger than the length b. A display device. (t1 / t2)×3 > a / b

2. The thickness t1 is larger than the thickness t2. The display device according to Claim 1.

3. The thickness t1 is larger than the thickness t3 of the protruding portion in the second direction. The display device according to Claim 1.

4. The thickness t2 and the thickness t3 are the same. The display device according to Claim 3.

5. Outer surfaces on both sides of the straight portion in the second direction are formed as inclined surfaces that approach each other in the second direction as they move away from the connecting portion in the third direction at least in part. The display device according to Claim 1.

6. Comprising a rear cover disposed behind the display panel. The straight portion and the connecting portion are provided on the rear cover. The display device according to Claim 1.

7. The base portion is located on the outer surface side of the connecting portion. The display device according to Claim 6.

8. A space surrounded by adjacent straight portions and adjacent connecting portions in the first direction is formed as an intake and exhaust hole. The display device according to Claim 1.

9. Comprising a display panel. The plurality of straight portions form a rear cover disposed on the back surface of the display panel in the third direction. The display device according to Claim 1.

10. 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 peripheral portions are arranged so as to sandwich the plurality of straight portions from the second direction. The display device according to Claim 9.

11. The back cover includes a series of first exhaust holes, The series of first exhaust holes are formed as a plurality of holes, Each of the plurality of holes is a hole surrounded by the straight portion and the connecting portion, The display device according to claim 9.

12. A bezel located in front of the back cover in the third direction and surrounding the display panel, The display device according to claim 9.

13. The bezel is provided with second exhaust holes, The display device according to claim 12.

14. A bezel located in front of the back cover in the third direction and surrounding the display panel, Second exhaust holes are formed in the bezel, The display device according to claim 10.

15. The back cover has a central portion that constitutes the straight portion and is surrounded by the outer peripheral portion, The display device according to claim 10.

16. Comprising an electronic substrate that generates heat, The electronic substrate is disposed between the display panel and the back cover, The heat is discharged from the first exhaust holes, The display device according to claim 11.

17. The back cover includes a series of first exhaust holes, Comprising an electronic substrate that generates heat, The electronic substrate is disposed between the display panel and the back cover, The heat is discharged from the first exhaust holes and the second exhaust holes, The series of first exhaust holes are formed as a plurality of holes, Each of the plurality of holes is a hole surrounded by the straight portion and the connecting portion, The display device according to claim 14.

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