JP5261957B2 - Video display device - Google Patents

Description

  The present invention relates to a video display device, and more particularly to a video display device devised to improve the reliability of a device when a circuit board is coupled to a chassis.

  When a plurality of circuit boards are used in a video apparatus or the like and these circuit boards are coupled to each other, it is necessary to enhance the grounding between the circuit boards to improve noise resistance against video processing or the like. As a prior art for that purpose, for example, the one described in Patent Document 1 below is known. In this patent document 1, in an electronic camera device, an image pickup device and an image processing circuit are divided into separate substrates, the ground of the image pickup device bracket and the ground of the circuit substrate of the image processing circuit are opposed to each other, and the ground is expanded and contracted. It discloses that it was connected with a conductive member.

JP 2006-211049 A

  By the way, in a video display device, for example, a cable (for example, DVI (Digital Visual Interface) or HDMI (High Definition) for transmitting a video signal from an external video device such as a PC, a DVD player / recorder, or an HDD player / recorder. Multimedia Interface)) is inserted or inserted into the terminal. A circuit board having a video processing circuit for processing the terminal and the input video signal is attached to a metal chassis disposed on the back surface of the video display device. This chassis also has a role of preventing electromagnetic waves (unnecessary copying) from the display panel or the like from leaking to the outside, and also functions as a so-called ground.

  In a flat type video display device using a liquid crystal display panel or a plasma display panel, a chassis and a circuit board are arranged in parallel to the main plane of the display panel, and a cable connector is inserted vertically from the back of the video display device It becomes. For this reason, in such a video display device, the insertion direction of the cable connector with respect to the terminal is a direction perpendicular to the main plane of the circuit board or chassis. Therefore, when the circuit board and the chassis are fixedly connected to each other with screws or the like, the tolerance for the variation in the distance between the circuit board and the chassis, that is, the margin is reduced, and the circuit when the cable connector is inserted into the terminal It becomes impossible to absorb the deformation of the substrate. Therefore, in such a case, when the cable connector is inserted into the terminal, the circuit board may be damaged by the force applied to the terminal during the insertion.

  In order to solve this problem, as described in Patent Document 1, when an elastic member is sandwiched between these circuit boards and combined, the force applied to the terminal can be absorbed by the elastic member. . However, the elastic member has a weak contact (contact) force with respect to the circuit board and the chassis, and the conductivity between the circuit board and the chassis is reduced. Therefore, when the circuit board and the chassis are joined to each other at a plurality of joints, it is difficult to satisfactorily ground the circuit board if elastic members are used at all the joints. In Patent Document 1, no consideration is given to the circumstances of such a video display device (particularly in a flat-type video display device).

  Therefore, in the video display device, it is important to improve the reliability of the video display device by improving the grounding of the circuit board and reducing the damage when inserting the connector of the cable to the terminal.

  The present invention has been made in view of the above problems, and an object thereof is to improve the reliability of the video display device in a video display device including a circuit board having a terminal and a chassis. It is to provide a suitable technique.

  In order to achieve the above object, the present invention is characterized by the structure described in the claims. That is, when a circuit board and a chassis provided with a terminal into which a connector of a cable for transmitting a video signal is inserted and the circuit board and the chassis are coupled to each other at a plurality of coupling portions, the plurality of couplings Among the parts, at least the coupling part close to the terminal is configured to include an elastic member, and the circuit board and the chassis are coupled via the elastic member, and the coupling part is fixedly coupled at other coupling points. It is characterized by.

  Thereby, in the vicinity where the terminal of the circuit board is provided, the force applied to the circuit board when the connector of the cable is inserted into the terminal can be absorbed, while the contact between the circuit board and the chassis at the other connecting portion. Since (electrical connection) becomes stronger, the grounding can be improved. That is, according to the present invention, it is possible to prevent the circuit board from being damaged while improving the grounding.

  According to the present invention, it is possible to improve the reliability of the video display device.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 shows an appearance and a cross-sectional view of a video display device to which the present invention is applied. FIG. 1A is a view of the video display device as viewed from the front (video viewing side). In such a video display device, a display surface 1 of a display panel is arranged on the front surface, and a housing 3 is provided so as to surround it. A stand 2 for supporting the housing 3 is provided at the lower portion of the housing 3. As shown in FIG. 1B, a terminal board 4 on which a plurality of terminals 5 are arranged is exposed on the rear surface of the video display device. The terminal board 4 may be exposed to the outside for the first time by removing a cover (not shown) from the housing 3. The terminal board 4 is provided with a cable connector for transmitting the video signal for supplying a video signal from an external video device (PC, DVD player / recorder, HDD player / recorder, etc.). It includes an external input terminal to be connected and an external output terminal for outputting a video signal generated in the video display device to the outside. These terminals may be DVI terminals and HDMI terminals as described above, and may further be D terminals, RGB signal terminals, component signal (YCbCr signal) terminals, and video / audio (monaural / stereo) terminals. Further, the terminal board 4 also includes a TV signal terminal to which a television broadcast signal received by an antenna (not shown) is supplied.

  A vertical cross section (cross section in the broken line Y direction) of the video display device shown in FIGS. 1A and 1B is shown in FIG. In addition, illustration of the stand 2 is abbreviate | omitted in FIG.1 (c). As shown in FIG. 1C, the video display device according to this embodiment includes, for example, a display panel 6 including a liquid crystal panel and a plasma display panel, a chassis 7, In addition, a circuit board 8 including a signal processing circuit 12 and a terminal 5 configured by, for example, an LSI for processing a video signal is arranged. The signal processing circuit 12 may be, for example, one that performs color correction, contrast correction, and γ correction on the input video signal, and further, a scaling process that increases or decreases the number of pixels of the input video signal in accordance with the resolution of the display panel 6. A frame rate conversion process for converting the number of frames of the input video signal may be performed. The video signal processed by the signal processing circuit 12 is supplied to the display panel 6 through the signal transmission line 11.

  The chassis 7 conducts heat from the display panel 6 and emits it to the outside. The chassis 7 is a ground for blocking unnecessary radiation so that electromagnetic waves (unwanted radiation) from the display panel 6 do not leak outside the apparatus. It also has a function as. On the other hand, in addition to the signal processing circuit 12, the circuit board 8 includes a decoder for combining digital video signals. Further, the circuit board 8 may be provided with a power supply circuit for supplying power to each part of the video display device, a tuner for selecting a television signal, and the power supply circuit and the tuner are separate circuit boards. You may comprise as.

  Here, the circuit board 8 and the chassis 7 are coupled to each other by the first coupling unit 9 and the second coupling unit 10. Here, the second coupling portion 10, which is closer to the terminal 5 than the first coupling portion 9, includes a conductive elastic member 23 formed by, for example, a coil spring or the like, and the elastic member 23 is interposed through the elastic member 23. Thus, the circuit board 8 and the chassis 7 are coupled. Therefore, the elastic member 23 exerts an elastic force in a direction perpendicular to the main plane of the circuit board 8 and the chassis 7 (left and right direction in FIG. 1C). On the other hand, in the first coupling portion 9 which is farther from the terminal 5 than the second coupling portion 10, the circuit board 8 and the chassis 7 are fixedly coupled by a non-elastic conductive member such as a screw. Is done. Both the screw used for the first coupling portion 9 and the elastic member used for the second coupling portion 10 have conductivity.

  In this embodiment, a cable connector (not shown) is inserted into the terminal 5 from a direction perpendicular to the main plane of the circuit board 8 and the chassis 7. Accordingly, the force applied to the terminal 5 when the cable connector is inserted acts in a direction perpendicular to the main plane of the circuit board 8 and the chassis 7. Therefore, as in the present embodiment, by using the elastic member 23 for the second coupling portion 10 closer to the terminal 5 of the circuit board 8, the terminal 5 of the circuit board 8 having a large force applied when inserted into the terminal is used. In the vicinity, the elastic member 23 can absorb the force. On the other hand, the first coupling portion 9 apart from the terminal 5 where the force does not act greatly when the connector of the cable is inserted fixes the circuit board 8 and the chassis 7 to strengthen the contact (that is, electrical connection) with each other. To improve the earth.

  Next, details of the connection between the circuit board 8 and the chassis 7 in this embodiment will be described with reference to FIGS. 2 shows the entire circuit board 8 and chassis 7 coupled to each other. FIG. 3 is an enlarged view of a portion surrounded by a dotted line A in FIG. 2, and FIG. 4 is surrounded by a dotted line B in FIG. The enlarged view of the part is shown. 2 is a view of the circuit board 8 and the chassis 7 as viewed from above, the lower figure is a horizontal sectional view of the circuit board 8 and the chassis 7, and the right figure is a circuit board 8 and the chassis. 7 shows a vertical sectional view of FIG.

  In FIG. 2, the terminal metal 21 constitutes the terminal board 4, and the connector insertion port of the terminal 5 is coupled by the machine screw 24. Here, it is assumed that the terminal 5 includes one DVI input terminal and two HDMI input terminals. Furthermore, these terminal groups are provided in a concentrated manner in the lower half area of the circuit board 8 when the circuit board 8 is divided into upper and lower parts with reference to the chain line X extending in the horizontal direction of the screen of the display panel 6 as the main plane of the circuit board 8. . Therefore, in this example, the terminal 5 is not provided in the upper half region of the circuit board 8. The terminal 5 is fixed and coupled to the circuit board 8, and the circuit board 8 is coupled to the chassis 7 by two first coupling portions 9 and two second coupling portions 10.

  That is, in this example, the circuit board 8 and the chassis 7 are coupled to each other at a total of four locations, and the first coupling portion 9 located far from the terminal 5 is integrated with the chassis 7 by the star screw 22. The circuit board 8 is joined to the bowl-shaped pedestal 26 that is formed as a result. At this time, as shown in the lower and right views of FIG. 2, and FIGS. 3 and 4, there is a space between the star screw 22 and the circuit board 8 and between the circuit board 8 pedestal 26. The metal mask 25 is sandwiched between the metal mask 25, thereby improving the conductivity between the star screw 22, the circuit board 8 and the chassis 7.

  On the other hand, in the second coupling portion 10 located near the terminal 5, an elastic member 23 is provided between the circuit board 8 and the chassis 7, and the elastic member 23 is sandwiched between the circuit board 8 and the chassis 7. To combine them. In the present embodiment, as the elastic member 23, for example, “FG spacer / FGS” manufactured by Kitagawa Industry Co., Ltd. can be used. This elastic member (FG spacer / FGS) is provided with a resin engagement portion whose both ends are inserted into holes provided in advance in the circuit board 8 and the chassis 7, and further between the engagement portions. A metal elastic body is formed. By using this, it is possible to easily couple the first circuit board 8 and the chassis 7 while applying an elastic force between them. The elastic member 23 is not limited to this, and for example, a coil spring or a leaf spring may be used.

  When the circuit board 8 and the chassis 7 are coupled, holes are provided in the circuit board 8 and the chassis 7 in advance, and the star screw 22 and the elastic member 23 are inserted into the holes and coupled to each other. At this time, when the positions of holes provided in advance in the circuit board 8 and the chassis 7 are different from each other, for example, the distance between two holes corresponding to the first coupling portion 9 in the circuit board 8 and the first coupling in the chassis 7. In the case where the distances between the two holes corresponding to the portion 9 are different from each other, if all the coupling portions (coupling locations) are fixedly coupled (without applying elastic force) with the star screw 22, the circuit board 8 A stress (stress) is always applied to the owing to the difference in the distance (in other words, the position of the hole). Further, when the insertion opening of the terminal 5 is attached to the terminal metal 21 with the small screw 24, when the terminal metal 21 has a relative displacement between the screw attachment hole and the screw attachment hole of the circuit board 8, the terminal 5 Even when the terminal metal 21 is screwed, the circuit board 8 is always stressed. When a cable connector is inserted into the terminal 5 in a state where such stress is generated, a force at the time of insertion is applied to the circuit board 8 together with the already generated stress. May be damaged.

  In order to prevent this, in this embodiment, as described above, the circuit board 8 and the chassis 7 are coupled using the elastic member 23 at the position near the terminal 5 or at the plurality of second coupling portions 10. I made it. In the example of FIG. 2, since the terminal 5 is provided in the lower half region of the circuit board, the coupling portion (coupling location) located in the lower half region is the second coupling portion 10 using the elastic member 23. . On the other hand, since the terminal 5 is not provided in the upper half region, the coupling portion (coupling portion) located in the upper half region is the first coupling portion 9 that does not use the elastic member 23. As a result, in the lower half area of the circuit board, as shown by the arrows in FIG. 4, the circuit board 8 and the chassis 7 are repelled from being sandwiched in the direction orthogonal to the main plane of the circuit board 8 and the chassis 7. Elastic force is generated. That is, at least in the lower half region of the circuit board, the circuit board 8 can be allowed to fluctuate or be deformed with the insertion of the cable connector into the terminal 5. Therefore, according to the present embodiment, the lower half region where the terminal 5 is disposed can be prevented from being damaged by absorbing the stress and the force at the time of insertion into the terminal by the elastic member, while the upper half region is Increases electrical conductivity and improves grounding.

  In this way, in this embodiment, it is possible to prevent the circuit board from being damaged while improving the grounding. Therefore, according to this embodiment, it is possible to improve the reliability of a video display device, particularly a video display device using a flat display panel.

  In the example of FIG. 2, the number of the second coupling portions 10 using the elastic member 23 is two, but is not limited to this. For example, the number may be three, or one closest to the terminal 5. It is good only as well. In addition, the circuit board 8 is divided into two regions, a region where the terminals 5 are provided and a region where the terminals 5 are not provided, and all the coupling parts included in the regions where the terminals 5 are provided are elastic members regardless of the distance from the terminals 5. It is also possible to use the second coupling portion 10 by 23 and all the coupling portions included in the region where the terminal 5 is not provided as the first coupling portion 9 that does not use the elastic member 23 (enhanced conductivity). At this time, the circuit board may be divided in the horizontal (left / right) direction of the display panel 6 as shown in FIG. 2 or in the vertical (up / down) direction of the display panel 6.

INDUSTRIAL APPLICABILITY The present invention is used to improve the reliability when a circuit board having a terminal such as an external input terminal and a chassis are coupled to each other in a video display device using a display panel such as a liquid crystal display or a plasma display device. It is preferable.

The figure which shows an example in the video display apparatus with which this invention is applied. The figure which shows one Embodiment of this invention. The enlarged view of the part enclosed by the dotted line A of FIG. The enlarged view of the part enclosed by the dotted line B of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Display surface of a display panel, 2 ... Stand, 3 ... Housing | casing, 4 ... Terminal board, 5 ... Terminal, 6 ... Display panel, 7 ... Chassis, 8 ... Circuit board, 9 ... 1st coupling part, 10 ... 2nd coupling | bond part, 11 ... Signal transmission line, 12 ... Signal processing circuit, 22 ... Kikuza screw, 23 ... Elastic member.

Claims (3)

In the video display device,
A circuit board provided with a terminal into which a cable connector for transmitting a video signal is inserted;
A chassis to which the circuit board is attached;
A display panel for displaying video based on an input video signal,
The insertion direction of the connector of the cable with respect to the terminal is a direction perpendicular to the main plane of the circuit board and the chassis,
The circuit board and the chassis are coupled to each other by at least a first coupling portion that is far from the terminal and a second coupling portion that is near from the terminal;
The first coupling portion is a conductive screw, and is inserted into a hole provided in advance in the circuit board and the chassis ,
The second coupling part includes a member having a conductive elastic body inserted into a hole provided in advance in the circuit board and the chassis and sandwiched between the circuit board and the chassis. Video display device. 2. The video display device according to claim 1 , wherein the display panel is a flat display panel, and in the vertical section of the video display device, the flat panel is sequentially formed from the front surface of the video display device to the back surface of the video display device. A video display device, wherein a display panel of a type, the chassis, and the circuit board are arranged, and the terminals of the circuit board can be exposed to the outside on the back surface of the video display device. 3. The video display device according to claim 2 , wherein the flat display panel is a liquid crystal display panel or a plasma display panel.

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