JP2015166876A - Thin display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a technique which improves a structure so that the shape of a penetrating hole, which penetrates, for contacting a PWB (printed wiring board) with a metal plate member, of a backlight cover as a resin-made member allows a gasket to be automatically fixed.SOLUTION: As shown in Fig. 5 (a), in a state in which a backlight cabinet 20 is appropriately arranged on a back side of a backlight unit 30, a gasket 90 is inserted into a gasket arrangement part 40 to be arranged in a prescribed area for earth of the backlight unit 30. The gasket 90 retains the original shape thereof at this point of time. Then, as shown in Fig. 5 (b), a main PWB (printed wiring board) 50 is put on the gasket 90. Thus, as shown in Fig. 5 (c), the main PWB 50 is fixed to the backlight cabinet 20 so that the gasket 90 is crushed by a prescribed amount to be fixed.

Description

  The present invention relates to a thin display device, and more particularly to a thin display device having a function of securing a ground using a gasket between a circuit board (printed circuit board) and a metal plate.

  For LCD TVs under the backlight model, a resin backlight cover (middle cabinet) covers the metal plate member on which the LEDs are placed as the backlight, and the main PWB (printed wiring board) is placed on the resin member. The structure which attaches is known.

  With reference to FIG. 1, the attachment structure of the gasket 90 with respect to main PWB150 in a liquid crystal display device is demonstrated here. As shown in FIG. 1 (a), a gasket (conductive member) 190 is fixed to the PWB back surface 151 where the ground (GND) of the main PWB 150 is formed with a double-sided tape. As shown in FIG. 1B, in the set in which the resin back cabinet 120 is disposed on the back side (the upper side in the drawing) of the metal plate member 130 with the gasket 190 fixed to the main PWB 150. The gasket 90 is affixed to a predetermined region of the metal plate member 130 with a double-sided tape through the gasket penetration hole 140 formed in the back cabinet 120. As a result, the structure shown in FIG. 1C is obtained, and the main PWB 150 and the metal plate member 130 are appropriately brought into contact with each other via the gasket 190 to ensure conduction.

  This kind of technology and various things have been proposed. For example, there is a technique for further reducing the thickness of a communication portable terminal having a built-in antenna while preventing the result of antenna characteristics (see Patent Document 1). Specifically, a first resin cabinet in which the first sheet metal is insert-molded and a second resin cabinet in which the second sheet metal is insert-molded are provided. Further, a circuit board on which an antenna is printed is sandwiched between the first resin cabinet and the second resin cabinet, and the first sheet metal, the second sheet metal, and the antenna are separated by a plurality of conductive gaskets. Electrically connected.

JP 2010-109760 A

  By the way, the gasket 190 is fixed to the main PWB 150 and the metal plate member 130 only by double-sided tape. Moreover, since the back cabinet 120 is fixed through the gasket through-holes 140, televisions adopting such a structure have problems such as adhesive deterioration of the double-sided tape and variations in the way of attachment during assembly. It was. For example, as shown in FIG. 1D, it is assumed that the gasket 190 is detached from the gasket penetration hole 140 due to deformation or the like. When these problems become apparent, the gasket 190 that electrically connects the main PWB 150 and the metal plate member 130 may become unstable in contact and may deteriorate unnecessary radiation, or may come into contact with other parts and have an adverse effect. Also, in order to prevent such products from being shipped to the market, the labor of the inspection process has increased and countermeasures have been required.

  Moreover, in the technique disclosed in Patent Document 1, a conductive material is electrically connected and effectively used by using a gasket. In addition, positioning is performed by fixing with a double-sided tape or by making a hole in an intermediate resin cabinet. However, another technique has been demanded because deformation due to compression of the gasket cannot be suppressed and there is a possibility of contact with a non-contactable area. In addition, when an adhesive such as double-sided tape is peeled off, the gasket may move due to vibration or the like, and another countermeasure is required because countermeasures are required.

  This invention is made | formed in view of the above situations, Comprising: It aims at providing the technique which solves the said subject.

The thin display device of the present invention is arranged to face the back side of the backlight unit, and is arranged to face the back side with respect to the non-conductive plate member having a through hole and the non-conductive plate member. A circuit board, and a gasket disposed in the through hole and configured to maintain electrical connection between the predetermined ground region of the backlight unit and the circuit board, and the non-conductive plate member is disposed around the through hole. Includes a gasket fixing portion formed thicker than other portions.
Another thin display device of the present invention is disposed to face the back side of the backlight unit, and has a non-conductive backlight chassis provided with a through hole, and is opposed to the back side of the backlight chassis. A circuit board disposed, and a gasket disposed in the through hole and configured to maintain electrical connection between the predetermined ground region of the backlight unit and the circuit board, and the backlight chassis includes a periphery of the through hole. Includes a gasket fixing portion formed thicker than other portions.

  According to the present invention, the technology for improving the shape of the through hole of the backlight cover (middle cavity), which is a resin member that penetrates when the circuit board and the metal member are in contact, to a structure that can mechanically fix the gasket. Can provide.

It is a figure which shows the grounding structure by the gasket of the metal plate member and main PWB of the backlight in a liquid crystal television based on background art. It is a disassembled perspective view of the liquid crystal television based on 1st Embodiment. It is a figure which shows the grounding structure by the gasket of the metal plate member and PWB of the backlight in the liquid crystal television based on 1st Embodiment. It is the figure which paid its attention to the gasket arrangement | positioning part of the ground structure based on 1st Embodiment. It is a figure which shows the formation procedure of the grounding structure by a gasket based on 1st Embodiment. It is a figure which shows arrangement | positioning of the grounding structure by a gasket based on 2nd Embodiment. It is a figure which shows the gasket arrangement | positioning part based on 3rd Embodiment. It is a figure which shows the gasket arrangement | positioning part based on 4th Embodiment. It is a figure which shows the gasket arrangement | positioning part based on 5th Embodiment.

  Next, modes for carrying out the present invention (hereinafter, simply referred to as “embodiments”) will be specifically described with reference to the drawings.

<First Embodiment>
FIG. 2 is an exploded perspective view of the liquid crystal television 10 according to the present embodiment, which is schematically displayed by arranging the front side on the lower side in the drawing and the back side on the upper side in the drawing.

  As shown in the figure, a backlight unit 30 is disposed on the back side (upper side in the figure) of the display panel 12 so as to face each other. A front cabinet 11 is disposed on the front side (lower side in the figure) of the display panel 12.

  The backlight unit 30 is a so-called direct type backlight, and a plurality of LEDs are arranged as light sources on the front side of the metal plate member. Further, a resin-made backlight cabinet 20 is disposed on the back side of the backlight unit 30 so as to face each other. Further, the main PWB 50 is arranged to face a predetermined area on the back side. Further, the rear cabinet 13 is disposed to face the back side of the backlight cabinet 20 to which the main PWB 50 is attached.

  Although details will be described later, the backlight cabinet 20 is provided with a gasket arrangement portion 40 that communicates with the front and rear of the backlight cabinet 20. A gasket 90 having a predetermined size is arranged in the gasket arrangement portion 40, and a predetermined rectangular area 35 of the metal plate member of the backlight unit 30 and a predetermined ground circuit area (ground pattern) of the main PWB 50 are electrically connected. Connected.

  The perspective view of FIG. 3 focuses on the backlight cabinet 20 and the main PWB 50.

  As described above, the main PWB 50 is disposed and fixed on the back surface of the backlight cabinet 20. At this time, the main PWB 50 is grounded to the backlight unit 30 by the gasket 90. Various processing LSIs, input / output terminals, and the like are arranged on the upper surface on the back side (upper side in the figure) of the main PWB 50.

  Hereinafter, the grounding structure will be described with reference to FIGS. Here, FIG. 4 is a view focusing on the gasket arrangement portion of the ground structure. FIG. 5 is a diagram showing a procedure for forming a grounding structure using a gasket, and in particular, FIG. 5C corresponds to the AA cross section of FIG.

  As illustrated, the backlight cabinet 20 is formed with a gasket placement portion 40 for placing the gasket 90. The gasket 90 is a cube having a size of 15 mm × 15 mm × 15 mm, and has a cushioning property that can be crushed by a certain amount.

  The gasket placement portion 40 is formed of a square gasket penetration opening 42 and a wall portion 44 surrounding the four sides of the gasket penetration opening 42. From the viewpoint of considering the gasket 90 falling due to aging, etc., the wall 44 may be formed mainly around the area corresponding to the lower side when the liquid crystal television 10 is used upright. It does not have to be formed in a region corresponding to. However, in consideration of the case where the gasket 90 is displaced and deformed with the movement of the main PWB 50 or the like, it is preferably formed also in the upper side region. In addition, there is no way to completely form the wall surface, and a plurality of pin-like structures may be used.

  Here, the gasket penetration opening 42 has a size of 16 mm × 16 mm. Therefore, in the state where the gasket 90 is disposed, a gap of 0.5 mm in the vertical and horizontal directions is formed between the gasket 90 and the outer peripheral portion of the gasket penetration opening 42.

  The wall portion 44 is formed with a predetermined width so as to surround the gasket penetration opening 42 in a convex shape with a height of 3.5 mm on the back side. In addition, the thickness of the plate-shaped part of the backlight cabinet 20 is 3.0 mm. In the state where the liquid crystal television 10 is properly assembled, the distance between the backlight unit 30 (metal plate member 32) and the backlight cabinet 20 is 2.55 mm. Further, the distance between the front end of the wall 44 and the main PWB 50 is 2.5 mm. That is, the distance between the metal plate member 32 on the back side of the backlight unit 30 and the main PWB 50 is 11.55 mm, and the gasket 90 is fixed in a state of being crushed by 3.45 mm. Note that a rectangular area 35 of 18 mm in width and 15 mm in length is secured as a grounding area in the area where the gasket 90 is fixed on the front side of the main PWB 50 (the lower side in the figure and facing the backlight cabinet 20). Has been.

Here, the arrangement | positioning procedure of the grounding structure by a gasket is demonstrated.
First, as shown in FIG. 5A, in a state where the backlight cabinet 20 is properly disposed on the back side of the backlight unit 30, the gasket 90 is inserted into the gasket placement portion 40, and the backlight unit 30 is predetermined. Are disposed in the grounding area 35. At this time, the gasket 90 remains in its original form.

  Subsequently, as shown in FIG. 5B, the main PWB 50 is disposed from above the gasket 90, that is, from the back side. At this time, the distance between the main PWB 50 and the backlight cabinet 20 is set to 2.5 mm as described with reference to FIG. Therefore, as shown in FIG. 5C, the main PWB 50 is fixed to the backlight cabinet 20, whereby the gasket 90 is crushed and fixed by a predetermined amount. The length of the gasket 90 protruding from the upper end of the wall portion 44 of the gasket arrangement portion 40 is 5.5 mm from 8.95 mm before being crushed.

  As mentioned above, according to this embodiment, the mechanical strength of gasket fixation is ensured. That is, the width and area facing the side surface of the gasket 90 increase. For this reason, the shape deformation of the gasket 90 can be controlled when the gasket 90 is attached. Therefore, displacement due to vibration or the like is suppressed, and positioning at the time of attaching the gasket 90 is facilitated. Moreover, the stable contact and conduction | electrical_connection of main PWB50 and the metal plate member (backlight unit 30) which has arrange | positioned LED are ensured, and unnecessary radiation deterioration can be suppressed.

<Second Embodiment>
FIG. 6 is a view showing a gasket arrangement portion 40 according to the second embodiment. For example, as shown in FIG. 6A, a claw-like locking structure 46 may be formed on the inner surface of the wall portion 44. The gasket 90 is more firmly fixed. The locking structure 46 may be formed over the entire inner surface, or may be formed only in a partial region. The size of the locking structure 46 is set in consideration of the workability when the gasket 90 is disposed, the amount of deformation when the gasket 90 is crushed, and the balance of the fixing force. It is about 0.5 mm corresponding to a gap with 40. Further, as shown in FIG. 6B, holes 48 may be provided at two opposing portions of the wall portion 44, and the fixing bars 49 may be attached to these holes 48 so as to pierce and penetrate the gasket 90. . The number of fixing bars 49 penetrating the gasket 90 is not limited to one, and a plurality of fixing bars 49 may be used, or a structure that does not penetrate may be used.

  Although not particularly shown, the height of the wall portion 44 of the gasket placement portion 40 may be lowered only on the cushion portion surface of the gasket 90. The cushion 90 of the crushed gasket 90 is made to escape, and when the gasket 90 is deformed, contact with other than the ground pattern can be prevented.

<Third Embodiment>
FIG. 7 is a view showing gasket arrangement portions 240 and 340 according to the third embodiment, and corresponds to FIG.

  The gasket arrangement portion 240 shown in FIG. 7A has a configuration corresponding to the above-described wall portion 44 surrounding the periphery of the gasket penetration opening 42, and the first to fourth portions formed at the four corners of the gasket penetration opening 42. Protrusions 244a to 244d are provided. The first to fourth protrusions 244a to 244d have an L-shaped rib protrusion structure in a top view.

  The gasket placement portion 340 shown in FIG. 7B has a plate-like (rib-like) shape in the vicinity of the four sides of the gasket penetration opening 42 as a configuration corresponding to the wall portion 44 surrounding the periphery of the gasket penetration opening 42. 1st-4th wall part 344a-344d is provided. Contrary to the configuration of FIG. 7A, the four corners of the wall portion 44 are removed.

  With these structures, when the gasket 90 is crushed and deformed, the crushed portion is not formed with the first to fourth protrusions 244a to 244d or the first to fourth wall portions 344a to 344d. Since it fits in the four spaces, the position maintaining function of the gasket 90 works well against vibrations in all directions.

<Fourth Embodiment>
FIG. 8 is a cross-sectional side view showing a gasket arrangement portion 440 according to the fourth embodiment, and corresponds to FIG. The gasket placement portion 440 is formed with a wall portion 444 that protrudes up and down so as to surround the gasket penetration opening 442, that is, a wall portion 444 that protrudes to both the main PWB 50 and the backlight unit 30. And the gasket penetration opening 442 is formed in the inner wall surface of the wall part 444 so that the backlight unit 30 side may spread. That is, the gasket penetration opening 442 is a truncated quadrangular pyramid. The upper size of the gasket penetration opening 442 is substantially the same as the outer shape of the gasket 90.

  As shown in FIG. 8A, the gasket 90 is inserted into the gasket penetration opening 442 from above, and the state shown in FIG. 8B is obtained. In the state of FIG. 8B, a predetermined space X is formed between the wall portion 444 and the gasket 90. As shown in FIG. 8C, when the main PWB 50 is attached and the gasket 90 is crushed and deformed, the deformed portion swells into the space X between the wall portion 444 and the gasket 90. As a result, the deformed portion does not protrude from the main PWB 50 side. Therefore, the gasket 90 does not adversely affect the components and wiring mounted on the main PWB 50.

<Fifth Embodiment>
FIG. 9 is a cross-sectional side view showing a gasket arrangement portion 540 according to the fifth embodiment. In the gasket placement portion 540, an upper side wall portion 544a formed so as to surround the upper side of the gasket penetration opening 542, and a first lower side wall portion 544b and a second lower side wall portion 544c formed on the lower side are provided. Have. The upper wall portion 544a has a structure similar to that of the wall portion 40 shown in FIG. 6A, and a claw-like locking structure 546 is formed on the upper inner surface of the upper wall portion 544a. The gasket 90 that is locked to the locking structure 546 is formed with a predetermined cut or concave shape for determining the locking position.

  The first lower wall portion 544b corresponds to two wall portions on the back side and the near side (not shown) in the drawing. These first lower side wall portions 544b are formed in a rib shape extending vertically downward by a predetermined length. The second lower wall portion 544c corresponds to the two left and right wall portions in the drawing. These second lower side wall portions 544c are structured to spread outward.

  With such a structure, when the gasket 90 attached to the gasket placement portion 540 is crushed and deformed, the deformed portion is guided to the second lower side wall portion 544c spreading outward.

  The present invention has been described based on the embodiments. This embodiment is an exemplification, and it is understood by those skilled in the art that various modifications can be made to combinations of the respective components and the like, and such modifications are within the scope of the present invention.

DESCRIPTION OF SYMBOLS 10 LCD television 11 Front cabinet 12 Display panel 13 Rear cabinet 20 Backlight cabinet 30 Backlight unit 32 Metal plate member 35 Area | region 40,240,340,440,540 Gasket arrangement part 42,442,542 Opening 44,444 for gasket penetration Wall portions 46, 546 Locking structure 48 Hole 49 Fixing bar 50 Main PWB
90 Gaskets 244a to 244d First to fourth protrusions 344a to 344d First to fourth wall portions 544a Upper wall portion 544b First lower wall portion 544c Second lower wall portion

Claims (2)

A non-conductive plate member disposed opposite the back side of the backlight unit and provided with a through hole;
A circuit board disposed on the back side of the non-conductive plate member;
A gasket that is disposed in the through-hole and maintains electrical connection between a predetermined ground region of the backlight unit and the circuit board;
With
The non-conductive plate member includes a gasket fixing portion in which a periphery of the through hole is formed thicker than other portions. A non-conductive backlight chassis provided with a through-hole, facing the back side of the backlight unit,
A circuit board disposed opposite to the back side of the backlight chassis;
A gasket that is disposed in the through-hole and maintains electrical connection between a predetermined ground region of the backlight unit and the circuit board;
With
The thin-type display device, wherein the backlight chassis includes a gasket fixing portion in which a periphery of the through hole is formed thicker than other portions.

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