Display device

Abstract

The display device includes: a plurality of straight portions, wherein, when three mutually orthogonal directions are defined as a first direction, a second direction, and a third direction, the plurality of straight portions are positioned so as to extend in a first direction and separate from each other in a second direction; and a connecting portion connecting two adjacent straight portions in the second direction. The straight portions and the connecting portion are integrally formed by injection molding. The straight portions include: a base portion extending in the first direction; and a pair of protrusions protruding from both ends of the base portion in the second direction in the third direction. The connecting portion connects, at its two ends, each front end portion of the protrusions of the two adjacent straight portions.

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, such as televisions, have structures formed by injection molding. In such display devices, for example, in some cases, a back cover, which is part of the housing, is formed by injection molding. The back cover has multiple holes for air intake and exhaust to cool the heat generated inside the housing (for example, see Patent Document 1). This portion with multiple holes is formed in a lattice shape.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Publication No. 2011-095772 Summary of the Invention

[0006] Problems to be solved by the present invention

[0007] Meanwhile, when the lattice-shaped portion is formed by injection molding, the molten resin is divided and joined, and in some cases, a weld line is formed at the junction of the molten resins.

[0008] Since the weld line has a lower strength than other parts, the weld line may cause cracks or defects. For example, when cracks or defects occur during an impact test of a product, countermeasures are required.

[0009] The present technology has been made in view of such a problem, and an object thereof is to improve the strength of a portion where a hole is formed.

[0010] Solution to the problem

[0011] A display device according to the present technology includes: a plurality of straight portions extending in a first direction and positioned spaced apart from each other in a second direction, when three directions orthogonal to each other are a first direction, a second direction, and a third direction; and a connecting portion connecting corresponding portions of two adjacent straight portions in the second direction. The straight portions and the connecting portion are integrally formed by injection molding, the straight portions having a base extending in the first direction and a pair of protrusions protruding from both ends of the base in the second direction in the third direction, with both ends of the connecting portion being continuous with the respective front ends of the protrusions of the two adjacent straight portions.

[0012] Therefore, holes are formed between the straight sections. Furthermore, during injection molding, the flow rate of the molten resin when forming the base is higher than the flow rate of the molten resin when forming the connecting section. This facilitates the formation of a convergence point (weld line) in the connecting section where the molten resin flows divided by the holes meet.

[0013] In the above display device, the plurality of connection portions may be arranged apart from each other in the first direction.

[0014] Therefore, the strength of the straight portion is improved.

[0015] In the above display device, a pitch width a of adjacent connecting portions in the first direction, a length b of the connecting portion in the second direction, a thickness t1 of the base portion in the third direction, and a thickness t2 of the connecting portion in the third direction may satisfy the following formula:

[0016] (t1 / t2) 3 >a / b

[0017] Therefore, a weld line is easily formed in the connection portion.

[0018] In the above display device, the pitch width a may be greater than the length b.

[0019] Therefore, the space surrounded by the straight portion and the connecting portion is a long hole.

[0020] In the above display device, the thickness t1 may be greater than the thickness t2.

[0021] Therefore, the flow rate of the molten resin when forming the connecting portion is set to be slower than the flow rate of the molten resin when forming the base portion of the straight portion.

[0022] In the above display device, the thickness t1 may be greater than a thickness t3 of the protrusion in the second direction.

[0023] Therefore, the flow rate of the molten resin when forming the protrusion is set to be slower than the flow rate of the molten resin when forming the base of the straight portion.

[0024] In the above display device, the thickness t2 and the thickness t3 may be the same thickness.

[0025] Therefore, the thickness of the connecting portion or the protruding portion is not excessively reduced.

[0026] In the above display device, at least a portion of outer surfaces of 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 the distance from the connection portion in the third direction increases.

[0027] Therefore, the cross-sectional area of ​​the space forming the continuous portion between the base portion and the protruding portion in the mold for injection molding is reduced, and the molten resin hardly flows into the protruding portion.

[0028] The display device further includes a back cover disposed behind the display panel. The straight portion and the connecting portion may be disposed in the back cover.

[0029] Therefore, a weld line is easily formed in the connection portion of the rear cover.

[0030] In the above display device, the base may be located on an outer surface side of the connection portion.

[0031] Therefore, the connection portion where a weld line is likely to be formed is located closer to the inner space of the display device than the base portion.

[0032] In the above display device, a space surrounded by adjacent straight line portions and connecting portions adjacent to each other in the first direction may be formed as the intake and exhaust holes.

[0033] Therefore, heat generated from the electronic substrate or the like can be discharged from the intake and exhaust holes, and the strength of the structure for forming the intake and exhaust holes can be maintained at a certain level or above. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 is a perspective view of the display device.

[0035] Figure 2 Is the display device in a different Figure 1 perspective view of the direction.

[0036] Figure 3 This is the rear view of the back cover.

[0037] Figure 4 It is along Figure 3 End view taken along line AA.

[0038] Figure 5 Schematic diagram showing a state in which an impact is applied to the outer surface of the rear cover and the rear cover is elastically deformed.

[0039] Figure 6 It is along Figure 3 End view taken along line BB.

[0040] Figure 7 It is along Figure 3 End view taken along line CC.

[0041] Figure 8 is a rear view showing a process of forming a rear cover using molten resin.

[0042] Figure 9 It is along Figure 8 End view taken along line FF.

[0043] Figure 10 It shows the following Figure 8 A rear view of the subsequent process of forming the rear cover using molten resin.

[0044] Figure 11 It is along Figure 10End view taken along line FF.

[0045] Figure 12 It shows the following Figure 10 A rear view of the subsequent process of forming the rear cover using molten resin.

[0046] Figure 13 It is along Figure 12 End view taken along line FF.

[0047] Figure 14 It shows the following Figure 12 A rear view of the subsequent process of forming the rear cover using molten resin.

[0048] Figure 15 It is along Figure 14 End view taken along line FF.

[0049] Figure 16 It is an end view showing the thickness of the base portion, the thickness of the protrusion, and the thickness of the connecting portion.

[0050] Figure 17 This is an end view for describing an example in which the timing of the molten resin flowing in the protrusion is taken into consideration.

[0051] Figure 18 is a schematic diagram showing exemplary dimensions.

[0052] Figure 19 1 and 2 are cross-sectional views and end views showing the straight portion and the connecting portion in a modified example.

[0053] Figure 20 1 is a view showing a state in which one end of the connecting portion is formed into the connecting portion. DETAILED DESCRIPTION

[0054] Hereinafter, the embodiments will be described in the following order.

[0055] <1. Configuration of Display Device>

[0056] <2. Back cover structure>

[0057] <3. Injection Molding Method for Back Cover>

[0058] <4. Pressure loss of molten resin>

[0059] <5. Example Dimensions>

[0060] <6. Modifications>

[0061] <7. Summary>

[0062] <8. This technology>

[0063] <1. Configuration of Display Device>

[0064] Will refer to Figure 1 and Figure 2 The configuration of the display device 1 of the present technology is described. Note that the display device 1 is a device on which videos or images are displayed, such as a television device or a monitor device.

[0065] The display device 1 includes: a display unit 2 having a generally rectangular shape; a support unit 3 attached to a rear surface portion of the display unit 2 and extending in the up-down direction; and a base portion 4 to which a lower end portion of the support unit 3 is attached, and the base portion 4 has a flat shape in the horizontal direction so as to stabilize the postures of the display unit 2 and the support unit 3.

[0066] In the following description, the front-to-back direction is described with the user viewing the video (image) displayed on the display device 1 as the front side. In addition, the direction of gravity is sometimes described as the up-down direction, and the horizontal direction is sometimes described as the left-right direction. Note that the left-right direction refers to the direction viewed from the back of the display device 1.

[0067] It should be noted that the "first direction," "second direction," and "third direction" in the claims refer to the aforementioned up-down, left-right, and front-back directions, respectively. However, these directions are determined based on the opening directions of the air intake and exhaust holes, which will be described later. Specifically, since the air intake and exhaust holes described in this embodiment open rearward, the first direction is the up-down direction. For example, if the air intake and exhaust holes open downward, the first direction is the front-back direction, the second direction is the left-right direction, and the third direction is the up-down direction.

[0068] It should be noted that these directions are only used for description, and in the implementation of the present technology, the present invention is not limited to these directions.

[0069] The display unit 2 includes: a housing portion 5 that accommodates each unit such as an electronic circuit for displaying images, etc. and has an opening that opens forward; and a display panel 6 that displays images, etc. and is arranged so that the images, etc. are visible from the front through the opening of the housing portion 5.

[0070] For example, the housing portion 5 includes a bezel 7 formed as a front side portion, a rear cover 8 formed as a rear side portion and positioned behind the display panel 6 , and various operators (not shown).

[0071] The frame 7 includes: an upper surface portion 9 that faces vertically and extends in the left-right direction; a pair of side surface portions 10 and 10 that face horizontally and are continuous with the left and right ends of the upper surface portion 9 and extend in the vertical direction; a lower surface portion 11 that faces vertically and has left and right ends that are continuous with the lower portions of the pair of side surface portions 10 and 10; and a frame portion 12 formed in a front-to-back frame shape. The outer periphery of the frame portion 12 is continuous with each front end of the upper surface portion 9, the side surface portions 10 and 10, and the lower surface portion 11.

[0072] The rear cover 8 is a resin member formed into a front-rear facing plate shape by injection molding, and is attached to the rear end portion of the bezel 7 from the rear side.

[0073] The back cover 8 is provided with intake holes for drawing air into the interior space and exhaust holes for exhausting air from the interior space. Heat discharged from the substrate and the like arranged inside the display unit 2 is cooled through the intake and exhaust holes. These intake and exhaust holes will be collectively referred to as intake and exhaust holes 13.

[0074] The plurality of intake and exhaust holes 13 are provided in the rear cover 8 as holes opening rearward, downward, upward, and sideways. Alternatively, in addition to the intake and exhaust holes opening in these directions, intake and exhaust holes 13 opening in an oblique direction may be used. The portion where the plurality of intake and exhaust holes 13 are formed is arranged in a lattice shape.

[0075] It should be noted that the air intake and exhaust holes 13 may be provided in the frame 7. For example, Figure 2 The intake and exhaust holes 13 shown in FIG. 1 are exemplified as holes formed in the rear cover 8 to open rearward and holes formed in the lower surface portion 11 of the bezel 7 to open downward.

[0076] In the following description, the air intake and exhaust holes 13 opening to the rear side of the rear cover 8 will be described. Various shapes of the air intake and exhaust holes 13 can be considered, but in this example, the air intake and exhaust holes 13 having an elongated shape in the vertical direction are exemplified.

[0077] The display panel 6 has a laminated structure including a diffusion plate, an optical sheet, a wiring layer, and the like.

[0078] <2. Back cover structure>

[0079] Will refer to Figure 3 The specific configuration of the rear cover 8 is described.

[0080] The predetermined portion of the rear cover 8 includes a central portion 14 in which a plurality of air intake holes 13 are formed, and an outer peripheral portion 15 as other portions.

[0081] The portion of the outer peripheral portion 15 excluding the outermost edge portion 15a includes a plurality of straight portions 16 extending in the up-down direction and positioned so as to be separated from each other in the left-right direction, and a connecting portion 17 positioned between the straight portions 16. A recessed portion opening rearward is formed between adjacent straight portions 16.

[0082] Next, we will refer to Figure 4 The straight portion 16 and the connecting portion 17 are described.

[0083] The straight portion 16 includes a base portion 18 extending in the vertical direction and having a substantially rectangular parallelepiped shape, and a pair of protruding portions 19 and 19 protruding forward from left and right end portions of the base portion 18 and having a substantially rectangular parallelepiped shape extending in the vertical direction.

[0084] Here, the protrusion 19 protruding from the left end of the base 18 is referred to as a protrusion 19L, and the protrusion 19 protruding from the right end is referred to as a protrusion 19R. When the left and right protrusions are not distinguished, they are simply described as protrusions 19.

[0085] The left and right end portions of the connecting portion 17 are respectively continuous with the front end portion 20 of the protrusion 19R and the front end portion 20 of the protrusion 19L of the adjacent straight portion 16 .

[0086] The rear surface of the base 18 forms part of the outer surface 21 of the display device 1. The outer surface 21 undergoes, for example, surface treatment to smoothen the surface by eliminating unevenness, or embossing to form unevenness. Furthermore, the outer surface 21 is also the portion to which impact is applied during impact testing. Furthermore, the outer surface 21 is one of the portions that may be subjected to impact from users and the like after commercialization.

[0087] In the rear cover 8, the horizontal cross-sectional shape is formed to have an uneven shape (bellows shape) by the straight portion 16 and the connecting portion 17. In the case where an impact is applied to the rear cover 8, as shown in FIG. Figure 5 As shown, near point D where the impact is applied, each portion of the rear cover 8 is deformed so that the adjacent base portions 18 and 18 approach each other and the gap between the pair of protrusions 19L and 19R of the straight portion 16 widens.

[0088] Therefore, the impact applied to the rear cover 8 is absorbed by deformation before being transmitted to the connecting portion 17 and the protruding portion 19 , and thus large stress is not generated in the connecting portion 17 and the protruding portion 19 .

[0089] Next, we will refer to Figure 3 、 Figure 6 and Figure 7 The central portion 14 of the rear cover 8 is described.

[0090] The central portion 14 of the rear cover 8 includes a plurality of straight portions 16 spaced apart from each other in the left-right direction and a plurality of connecting portions 22 spaced apart from each other in the up-down direction. Specifically, the plurality of connecting portions 22 are provided between two adjacent straight portions 16 and 16 and enhance the strength of the straight portion 16.

[0091] like Figure 7 As shown, the connecting portion 22 has a shape similar to the horizontal cross-section of the connecting portion 17. That is, the connecting portion 22 has a rectangular parallelepiped shape extending in the left-right direction, and its left and right ends are respectively continuous with the front end portion 20 of the protrusion 19R of the adjacent straight portion 16 and the front end portion 20 of the protrusion 19L of the straight portion 16.

[0092] The plurality of connection portions 22 are provided so as to be separated from each other in the up-down direction.

[0093] The space enclosed by the linear portions 16 and 16 adjacent to each other in the left-right direction and the connecting portions 22 and 22 adjacent to each other in the top-bottom direction forms the intake and exhaust holes 13. Heat generated by the electronic substrate and the like arranged in the housing portion 5 can be released to the outside through the intake and exhaust holes 13. Therefore, good heat dissipation can be ensured in the display device 1.

[0094] It should be noted that a space surrounded by the straight portions 16 and 16 adjacent to each other in the left-right direction, the end portion of the connecting portion 17 , and the connecting portion 22 is also formed as the intake and exhaust holes 13 .

[0095] Next, the length and thickness of each portion of the rear cover 8 will be described (see Figure 3 and Figure 7 ).

[0096] The thickness of the base portion 18 in the front-to-back direction is defined as thickness t1. The thickness of the connecting portion 22 in the front-to-back direction is defined as thickness t2. The thickness of the protruding portion 19 in the left-to-right direction is defined as thickness t3. The vertical pitch width between the connecting portions 22 and 22 is defined as pitch width a. The left-to-right length of the connecting portion 22 is defined as length b.

[0097] In this embodiment, for example, thickness t1 is larger than thickness t2 and thickness t3. In addition, thickness t2 and thickness t3 are the same.

[0098] Furthermore, the pitch width a is greater than the length b.

[0099] Note that the conditions for satisfying these thicknesses and lengths will be described again later.

[0100] <3. Injection Molding Method for Back Cover>

[0101] As described above, the rear cover 8 is formed by injection molding using molten resin.

[0102] Hereinafter, the process of forming each part of the rear cover 8 by injection molding will be described in chronological order (see FIG. Figures 8 to 15 ).

[0103] Figure 8 1 is a diagram showing a state where the molten resin PL flows in from the inflow position E to form the shown portion in the rear cover 8. The inflow position E is, for example, Figure 8 The portion closest to the gate (not shown) among the portions shown in FIG. Figure 8 The inflow position E shown in FIG. 8 is merely an example and may be arbitrarily set according to the position of the gate provided in the rear cover 8 .

[0104] Furthermore, the number of the inflow positions E is not necessarily one, and a plurality of inflow positions E may be provided.

[0105] Note that when the rear cover 8 is formed by injection molding, a gate may be provided at any position.

[0106] Note that in the following figures, the positional relationship between the rear cover 8 as the final molded product and the molten resin PL at this time (the satin portion in the figures) is shown. Figure 8 The flow state in the internal space (cavity) of the mold cut by the dot-dash line FF shown in FIG.

[0107] like Figure 8 and Figure 9 As shown, the molten resin PL is caused to flow 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.

[0108] As described above, the thickness t1 of the base portion 18 in the front-to-back direction is greater than the thickness t3 of the protruding portion 19 in the left-to-right direction. Therefore, the molten resin PL flows faster in the front-to-back direction within the space forming the protruding portion 19 than it flows in the vertical direction within the space forming the base portion 18. Consequently, there is a situation where the molten resin flows into the base 18 but does not flow into the protruding portion 19. Consequently, 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 in the connecting portion 22.

[0109] Then, if Figure 10 and Figure 11 As shown, the molten resin PL flows from the space forming the straight portion 16A to the space forming the connecting portion 22 via the space forming the protruding portion 19R, and flows from the space forming the base 18 of the straight portion 16B to the space forming the protruding portion 19L.

[0110] Then, if Figure 12 and Figure 13As shown, the molten resin PL flows from the space where the straight portion 16A is formed to the space where the connection portion 22 is formed, and flows from the space where the protruding portion 19L is formed toward the space where the connection portion 22 is formed.

[0111] Then, if Figure 14 and Figure 15 As shown, the molten resin PL merges in the space forming the connection portion 22. Therefore, a weld line W of the molten resin PL is formed in the space forming the connection portion 22.

[0112] As described above, the thickness t1 of the base portion 18 in the front-rear direction is greater than the thickness t2 of the connecting portion 22 in the front-rear direction. Therefore, the velocity of the molten resin PL flowing in the left-right direction in the space forming the connecting portion 22 (see FIG. Figure 13 and Figure 15 ) is greater than the velocity of the molten resin PL flowing in the vertical direction in the space forming the base 18 (see Figure 12 and Figure 14 )slow.

[0113] Therefore, the weld line W can be easily formed in the connection portion 22 .

[0114] It should be noted 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.

[0115] To form a confluence point of the molten resin PL in the connection portion 22, it is conceivable to reduce the thickness t3 of the protrusion 19 or the thickness t2 of the connection portion 22. If only one of the thicknesses t2 and t3 is reduced, the strength of the portion with the reduced thickness decreases, and breakage or cracking may occur.

[0116] When the thickness t2 of the connection portion 22 is made the same as the thickness t3 of the protrusion 19, the connection portion 22 and the protrusion 19 can be formed to have a specific thickness compared to the case where only one of the thicknesses t2 and t3 is reduced. Therefore, while ensuring the strength of the protrusion 19 and the connection portion 22, the flow rate of the molten resin PL when forming the protrusion 19 and the connection portion 22 can be reduced, and the durability of the back cover 8 can be improved.

[0117] As shown in the drawings, base portion 18 is located on the outer surface side (rear side) of connection portion 22. Therefore, connection portion 22, where weld line W is likely to be formed, is closer to the interior space of display device 1 than straight portion 16.

[0118] Therefore, impact is less likely to be applied to the connection portion 22 where weld lines W may form, and thus, fractures and cracks caused by weld lines W are less likely to occur, thereby improving the durability of the back cover 8. Furthermore, when the base 18 serves as the outer surface 21 of the display device 1, an impact may be applied to the base 18 during an impact test. In this case, since weld lines W are not formed in the base 18, the impact test is easily passed, and no countermeasures are required. Consequently, unnecessary man-hours can be reduced.

[0119] <4. Pressure loss of molten resin>

[0120] The flow rate of the molten resin PL during injection molding corresponds to the magnitude of the pressure loss generated when the molten resin PL flows within the mold. That is, the greater the pressure loss, the lower the flow rate.

[0121] The pressure loss ΔP is calculated by the following formula (1).

[0122] ΔP=12μLQ / (wt 3 )...Formula (1)

[0123] 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.

[0124] Hereinafter, a specific example of pressure loss associated with the rear cover 8 will be described using a pitch width a in the vertical direction of a plurality of connection portions 22 spaced apart from each other in the vertical direction and a length b of the connection portions 22 in the left-right direction.

[0125] In order to form the weld line W in the portion other than the straight portion 16, it is required to form the straight portion 16 ( Figure 9 Before the molten resin PL of the straight portion 16A in the middle completes the formation of the connecting portion 22, it flows through the adjacent straight portion 16 ( Figure 9 The molten resin PL of the straight portion 16B in the middle completes the formation of the base 18.

[0126] In order to satisfy this condition, the time required to form the base portion 18 of the straight portion 16 across the pitch width a needs to be shorter than the time required to form the connecting portion 22 across the length b.

[0127] When the base portion 18 forming the straight portion 16 spans the pitch width a, the pressure loss ΔP1 of the molten resin PL can be expressed by the following formula (2) (see Figure 16 ).

[0128] ΔP1=12μaQ / (w×t1 3 )...Formula (2)

[0129] Furthermore, the pressure loss ΔP2 when the molten resin PL flows from one end to the other end of the connection portion 22 can be expressed by the following formula (3) (see Figure 16 ).

[0130] ΔP2=12μbQ / (w×t2 3 )...Formula (3)

[0131] In order to form the weld line W in the connection portion 22 , the pressure loss ΔP1 is required to be smaller than the pressure loss ΔP2 .

[0132] That is, the following formula (4) is derived from formula (2) and formula (3).

[0133] (t1 / t2) 3 >a / b..Formula (4)

[0134] By satisfying the above expression (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 forming the entire connecting portion 22 when forming the base portion 18. Therefore, since the weld line W is not formed in the straight portion 16, the strength of the straight portion 16 can be improved.

[0135] Note that various combinations of variables t1, t2, a, and b that satisfy equation (4) can be considered.

[0136] However, the value of variable t1 is the thickness of the base portion 18 in the front-to-back direction, which is naturally determined by the design when considering the strength and weight of the rear cover 8. Furthermore, the value of variable a is the vertical pitch width between the connecting portions 22 and 22, which is naturally determined when considering the size of the air intake and exhaust holes 13. Furthermore, the value of variable b is the horizontal length of the connecting portion 22, which is also naturally determined when considering the size of the air intake and exhaust holes 13.

[0137] Therefore, based on the values ​​of the variables t1, a, and b, the value of the variable t2 is derived from the formula (4) as a value smaller than the predetermined value.

[0138] In order to form the fusion line W in the connecting portion 22, in order to satisfy the formula (4), the variable t2 needs to be smaller than a predetermined value, but on the other hand, considering the durability of the rear cover 8, etc., the thickness t2 of the connecting portion 22 in the front-to-back direction cannot be made too small, and it is desirable to make the variable t2 as large as possible.

[0139] Therefore, conditions for increasing the value of the thickness t2 will be described below.

[0140] In the display device 1, it is most desirable to form the weld line W in the connecting portion 22 in order to ensure high strength of the rear cover 8, but it is also permissible to form the weld line W in the protruding portion 19 or the connecting portion 22 other than the base 18. Even in the case where the weld line W is formed in the protruding portion 19, sufficient strength of the rear cover 8 can be ensured, and by relaxing the expression (4) as a condition for forming the weld line W in the protruding portion 19 to a 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.

[0141] To form the weld line W in the protrusion 19 or the connection 22 , the total 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 connection 22 only needs to be greater than the pressure loss ΔP1 .

[0142] That is, Figure 17 As shown, when the path of the molten resin PL flowing from the space of the protrusion 19R forming the straight portion 16A to the space of the protrusion 19L forming the straight portion 16B through the space forming the connecting portion 22 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 greater than the pressure loss ΔP1.

[0143] Here, if only one of the thickness t2 of the connecting portion 22 in the front-to-back direction and the thickness t3 of the protruding portion 19 in the left-to-right direction is reduced, there is a possibility that the strength of the portion with the reduced thickness will be excessively reduced. Therefore, it is desirable that the thickness t2 of the connecting portion 22 in the front-to-back direction and the thickness t3 of the protruding portion 19 in the left-to-right direction have the same thickness.

[0144] The pressure loss ΔP3 when the thickness t2 and the thickness t3 are the same value is expressed by the following formula.

[0145] ΔP3=12μb'Q / (w×t2 3 )...Formula (5)

[0146] b' is the path length of the path G and can be expressed by the following equation (6).

[0147] b'=2c-t2+b+t3

[0148] =2c-t2+b+t2

[0149] =2c+b...Formula (6)

[0150] In order to form the weld line W in the portion on the path G, that is, the protrusion 19 or the connection portion 22, it is sufficient to make the pressure loss ΔP3 greater than the pressure loss ΔP1. Therefore, the following equation (7) can be derived from equations (2), (5), and (6).

[0151] (t1 / t2)3 >a / b'

[0152] (t1 / t2) 3 >a / (2c+b)...Formula (7)

[0153] Based on equations (4) and (7), possible values ​​of thickness t2 are expanded as follows.

[0154] Since c>0, (2c+b) is a value larger than b, and a / (2c+b) in the formula (7) is a value smaller than a / b.

[0155] In contrast to equation (4), equation (7) indicates that (t1 / t2) can be a smaller value. Therefore, equation (7) can set t2 to a value greater than t2 in equation (4).

[0156] By determining thickness t2 based on equation (7), the thickness t2 of protrusion 19 and connection 22 can be further increased, thereby improving the strength of protrusion 19 and connection 22. Furthermore, during injection molding, after the molten resin PL formed at base 18 of straight portion 16A forms protrusion 19R and connection 22, the molten resin PL flows from base 18 of adjacent straight portion 16B into protrusion 19L before protrusion 19L of adjacent straight portion 16B is formed. That is, in the mold cavity, the molten resin PL flowing from the space forming each adjacent straight portion 16 to the space forming connection 22 therebetween converges at connection 22 or protrusion 19. Therefore, no weld line W is formed in straight portion 16, and the strength of straight portion 16 can be further improved.

[0157] Note that when the pitch width a of the connection portion 22 is made greater than the length b of the connection portion 22, the space enclosed by the straight portion 16 and the connection portion 22 forms an elongated intake and exhaust hole 13. Therefore, it is possible to prevent fingers, foreign matter, etc. from entering the display device 1 through the elongated intake and exhaust hole 13.

[0158] Note that it has been described here that the condition of the thickness t2 can be relaxed using variables other than the thickness t2 as constants, but the conditions of variables other than the thickness t2 can be relaxed by changing a combination of variables to constants.

[0159] <5. Example Dimensions>

[0160] Figure 18 Exemplary dimensions of the straight portion 16 and the connecting portion 22 are shown.

[0161] The left and right ends of the rear end portion of the base portion 18 are formed as corner portions 18a, respectively. In addition, the inner ends of the front end portions 20, 20 of the protruding portions 19L, 19R are formed as inner corner portions 20a, 20a, respectively.

[0162] First, the distance d between the protrusion 19R protruding from one base 18 and the portion of the protrusion 19L continuous with the base 18 is preferably set to a value not less than 2.3 times the thickness t2 of the connection portion 22 and the thickness t3 of the protrusion 19 .

[0163] Considering the ease of injection molding, it is difficult to form the thickness t2 of the connection portion 22 and the thickness t3 of the protrusion 19 to be less than 1 mm. For example, assuming that the thickness t2 of the connection portion 22 and the thickness t3 of the protrusion 19 are 1 mm, the distance d is preferably 2.1 mm or more.

[0164] Therefore, the speed of the molten resin when forming the protrusion 19 and the connection portion 22 is sufficiently slower than the speed of the molten resin PL when forming the base 18 , so that the weld line W is easily formed in the portion other than the base 18 .

[0165] The corners 18a and the inner corners 20a are preferably chamfered to prevent chipping, etc. The corners 18a are preferably chamfered to a radius of, for example, 0.5 mm to 1 mm, and the inner corners 20a are preferably chamfered to a radius of, for example, 0.3 mm.

[0166] Furthermore, the corners at both ends of the rear end portion of the connection portion 22 are formed to be greater than 180 degrees, which makes chipping less likely to occur, and therefore, does not require rounding.

[0167] Similarly, since the corner of the continuous portion provided between the base portion 18 and the protruding portion 19 is also formed to be 180 degrees or more, it is not necessary to perform R-chamfering.

[0168] Furthermore, in order to easily perform the step of releasing the rear cover 8 as a molded product from the mold, it is desirable that the angle r formed by the extension direction of the protrusion 19 and the front-rear direction is larger than 0 degrees. The angle r is, for example, 0.5 degrees or more.

[0169] Next, examples of possible numerical values ​​of the variables t1, t2, a, and b used in the above-mentioned formula (4) will be described.

[0170] The maximum vertical pitch width a of the connecting portion 22 is preferably below a predetermined value to prevent a decrease in the strength of the straight portion 16. Furthermore, from the perspective of heat dissipation efficiency, the pitch width a is preferably above a predetermined value. For example, the pitch width is 3 mm to 30 mm.

[0171] The length b of the connecting portion 22 in the left-right direction is ideally set to a predetermined value or less to prevent fingers, etc., from entering through the air intake and exhaust holes 13. Furthermore, from the perspective of heat exhaust efficiency, the length b is preferably greater than the predetermined value. For example, the length b is 1 mm or more and 30 mm or less.

[0172] To facilitate injection molding, the thickness t1 of the base 18 in the front-to-back direction is preferably set to a predetermined value or greater. Furthermore, to improve weight and cost, the thickness t1 is preferably set to a predetermined value or less. For example, the thickness t1 is 0.5 mm or greater and 4 mm or less.

[0173] From the perspective of ease of injection molding, the thickness t2 of the connecting portion 22 in the front-to-back direction is preferably set to a predetermined value or greater. Furthermore, from the perspective of weight and cost, the thickness t2 is preferably set to a predetermined value or less. For example, the thickness t2 is 0.5 mm or greater and 4 mm or less.

[0174] In order to form the weld line W in the portion other than the base 18 of the straight portion 16, the relationship between the thicknesses t1 and t2 is important. That is, it is desirable that the thicknesses t1 and t2 be set to satisfy the above-mentioned equations (4) and (7) while satisfying the conditions of 0.5 mm or more and 4 mm or less, respectively.

[0175] <6. Modifications>

[0176] A modification of the configuration of the straight portion 16 and the connecting portion 22 forming the intake and exhaust holes 13 will be described.

[0177] 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 18 .

[0178] Will refer to Figure 19 Give a specific description.

[0179] Figure 19 One straight portion 16C and a plurality of connecting portions 22 extending from the straight portion 16C in the left-right direction are shown. Figure 19 There are shown 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 up-down direction as an end view of a portion on which the connecting portion 22 is not located.

[0180] The straight portion 16C has a base portion 18C and protruding portions 19L and 19R.

[0181] The base portion 18C includes a protruding portion 24 as a rear portion and a base portion 25 as a front portion of the protruding portion 24 .

[0182] The protrusion 24 is formed in a rectangular horizontal sectional shape, and the base 25 is formed so that the horizontal sectional shape is an isosceles trapezoidal shape and the width in the left-right direction is greater than the width of the protrusion 24 .

[0183] The outer surface of the base portion 25 in the left-right direction is formed as inclined surfaces 26 , 26 that approach each other as approaching the protruding portion 24 .

[0184] By forming inclined surface 26 on straight portion 16C in this manner, corner 27 where the back surface of base 25 continues to inclined surface 26 has an angle greater than a right angle, making it difficult for corner 27 to be chipped.

[0185] Furthermore, when the straight portion 16C and the connecting portion 22 are formed during the injection molding process, the cross-sectional area of ​​the space formed in the continuous portion between the base portion 18C and the protrusion 19 is reduced. Specifically, the width t4′ of the base of the protrusion 19 when the inclined surface 26 is formed is shorter than the width t4 (= t2) of the base of the protrusion 19 when the inclined surface 26 is not formed.

[0186] Therefore, it is difficult for the molten resin PL to flow from the base 18C of the straight portion 16C to the protruding portions 19L and 19R. That is, the time required for the molten resin PL to reach the connecting portion 22 becomes longer, and the weld line W is more likely to form in the connecting portion 22. In addition, during the demolding process of injection molding, the molded product and the mold can be easily separated, and work efficiency can be improved.

[0187] 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 portion in the vicinity thereof, and is not formed in the portion between the adjacent connecting portions 22 and 22. Figure 19 shown in the end view.

[0188] The protruding portions 19L and 19R are formed so that the portion near the connection portion 22 is a wide portion 28 having a wider width in the left-right direction, and the other portion is a narrow portion 29 having a narrower width than the wide portion 28 in the left-right direction.

[0189] Therefore, when the molten resin PL flows downward from above when the straight portion 16C is formed, the flow rate is reduced when the narrow portion 29 is formed, compared to the case where the narrow portion 29 is not formed. Therefore, the time for the molten resin PL to flow into the wide portion 28 (which is the portion near the connecting portion 22) becomes longer, and the possibility of the weld line W being formed in the connecting portion 22 can be increased.

[0190] It should be noted that Figure 20 As shown, in the connection portion 17 , the edge portion of the air intake and exhaust hole 13 may be formed as a connection portion 22 .

[0191] Therefore, each intake and exhaust hole 13 is formed by a pair of straight portions 16 and 16 adjacent to each other in the left-right direction and a pair of connecting portions 22 and 22 adjacent to each other in the up-down direction. That is, the various functions and effects described above and below also apply to the intake and exhaust hole 13' formed by the pair of straight portions 16 and 16, one end portion of the connecting portion 17 in the up-down direction, and the connecting portion 22.

[0192] It should be noted that in the above example, the display device 1 includes a rear cover 8 having the air intake and exhaust holes 13 formed therein. However, the air intake and exhaust holes 13 may be formed in a rear cover, a side cover, or the like in the housing of another electronic device or the like. For example, in the case of a personal computer including various substrates or devices such as a motherboard and a housing arranged in an internal space, the air intake and exhaust holes 13 having the above characteristics may be formed on the back and side surfaces of the housing.

[0193] Furthermore, the holes formed by the straight portions and the connecting portions are not limited to intake and 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. It should be noted that although the example in which the connecting portion 17 is formed on the outer peripheral portion 15 of the rear cover 8 has been described above, the present technology can also be applied to a configuration in which the connecting portion 17 is not formed on the outer peripheral portion 15.

[0194] <7. Summary>

[0195] As described in the above examples, when the three directions orthogonal to each other are the first direction (up and down direction), the second direction (left and right direction), and the third direction (front and back direction), the back cover 8 of the display device 1 includes a plurality of straight portions 16 (16A, 16B, 16C) extending in the first direction (up and down direction) and positioned separately in the second direction (left and right direction), and a connecting portion 22 connecting corresponding portions of two straight portions 16 (16A, 16B, 16C) adjacent to each other in the second direction (left and right direction).

[0196] In addition, the straight portion 16 (16A, 16B, 16C) and the connecting portion 22 are integrally formed by injection molding, and the straight portion 16 (16A, 16B, 16C) has a base 18 (18C) extending in a first direction (up and down direction) and a pair of protrusions 19 (19L, 19R) protruding in a third direction (front and back direction) from both ends of the base 18 (18C) in a second direction (left and right direction), and both ends of the connecting portion 22 are continuous with the corresponding top ends 20 of the protrusions 19 (19L, 19R) of the two adjacent linear portions 16 (16A, 16B, 16C).

[0197] Therefore, holes (intake and exhaust holes 13) are formed between straight portions 16 (16A, 16B, 16C). Furthermore, the flow rate of molten resin PL when forming base portion 18 (18C) during injection molding is higher than the flow rate of molten resin PL when forming connecting portion 22. Therefore, the confluence point (weld line W) of the molten resin PL divided by the holes (intake and exhaust holes 13) is easily formed in connecting portion 22.

[0198] Since the weld line W is formed in the connection portion 22 , the strength of the base 18 ( 18C) can be improved.

[0199] Furthermore, due to the sawtooth shape (bellows shape) formed by alternately joining portions having U-shaped cross sections in the continuous portion of the straight portions 16 (16A, 16B, 16C) and the connecting portion 22, tensile stress is less likely to occur in the connecting portion 22 when an impact is applied to the base portion 18 (18C), and cracks and breakage are less likely to occur in the connecting portion 22. Consequently, the number of back covers 8 that fail the impact test is reduced, and countermeasures are unnecessary.

[0200] It should be noted that the effects described in this specification are merely examples and are not limiting, and other effects may be provided.

[0201] Furthermore, the above examples can be combined in any manner as long as the combination is not impossible.

[0202] <8. This technology>

[0203] This technology can also adopt the following configurations. (1)

[0205] A display device, comprising:

[0206] a plurality of straight line portions extending in the first direction and positioned apart from each other in the second direction when three directions orthogonal to each other are the first direction, the second direction, and the third direction; and

[0207] a connecting portion connecting corresponding portions of two straight line portions adjacent to each other in the second direction;

[0208] Wherein, the straight portion and the connecting portion are integrally formed by injection molding;

[0209] 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; and

[0210] Both end portions of the connecting portion are continuous with respective front end portions of the protruding portions of the two adjacent straight portions. (2)

[0212] The display device according to (1),

[0213] The plurality of connection portions are arranged separately from each other in the first direction. (3)

[0215] The display device according to (2),

[0216] The pitch width a of the connecting portions adjacent to each other 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 portion in the third direction satisfy the following formula:

[0217] (t1 / t2) 3 >a / b (4)

[0219] The display device according to (3),

[0220] The pitch width a is greater than the length b. (5)

[0222] The display device according to any one of (3) to (4),

[0223] The thickness t1 is greater than the thickness t2. (6)

[0225] The display device according to any one of (3) to (5),

[0226] The thickness t1 is greater than the thickness t3 of the protrusion in the second direction. (7)

[0228] The display device according to (6),

[0229] Here, the thickness t2 and the thickness t3 are the same thickness. (8)

[0231] The display device according to any one of (1) to (7),

[0232] At least a portion of outer surfaces of both sides of the straight portion in the second direction are formed as inclined surfaces, and the inclined surfaces approach each other in the second direction as the distance from the connecting portion in the third direction increases. (9)

[0234] The display device according to any one of (1) to (8), further comprising:

[0235] a back cover, which is arranged behind the display panel;

[0236] The straight portion and the connecting portion are arranged in the back cover. (10)

[0238] The display device according to (9),

[0239] The base is located on the outer surface side of the connecting portion. (11)

[0241] The display device according to any one of (3) to (7),

[0242] Here, a space surrounded by adjacent straight portions and connecting portions adjacent to each other in the first direction forms the intake and exhaust holes.

[0243] Explanation of symbols

[0244] 1 Display device

[0245] 8 Back cover

[0246] 13, 13' intake and exhaust holes

[0247] 16, 16A, 16B, 16C straight line

[0248] 18, 18C base

[0249] 19, 19L, 19R protrusions

[0250] 20 front end

[0251] 21 outer surface

[0252] 22 Connection

[0253] 26 Inclined surface

[0254] Pitch width;

[0255] b length

[0256] t1, t2, t3 thickness.

Claims

1. A display device comprising: a plurality of straight line portions, when three directions orthogonal to each other are a first direction, a second direction, and a third direction, the plurality of straight line portions extending in the first direction and positioned apart from each other in the second direction; as well as a connecting portion connecting corresponding portions of two straight line portions adjacent to each other 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 protrusions protruding in the third direction from both end portions of the base portion in the second direction, and The plurality of connecting portions are provided to be separated from each other in the first direction so that both ends of the connecting portion are continuous with the respective front end portions of the protruding portions of two adjacent straight portions, The pitch width a of the connecting portions adjacent to each other 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: (t1 / t2) 3 >a / b。 2. The display device according to claim 1, in, The pitch width a is greater than the length b.

3. The display device according to claim 1, in, The thickness t1 is greater than the thickness t2.

4. The display device according to claim 1, in, The thickness t1 is greater than the thickness t3 of the protrusion in the second direction.

5. The display device according to claim 4, in, The thickness t2 and the thickness t3 are the same thickness.

6. The display device according to claim 1, in, At least a portion of outer surfaces of both sides of the straight portion in the second direction are formed as inclined surfaces that approach each other in the second direction as the distance from the connecting portion in the third direction increases.

7. The display device according to claim 1, further comprising: a back cover, arranged behind the display panel; Wherein, the straight portion and the connecting portion are arranged in the back cover.

8. The display device according to claim 7, in, The base portion is located on an outer surface side of the connecting portion.

9. The display device according to claim 1, in, A space surrounded by the adjacent straight portions and the connecting portions adjacent to each other in the first direction is formed as an intake and exhaust hole.

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