JP5012172B2 - Flat panel display - Google Patents

Description

  The present invention relates to a flat display device, and is a flat type for stabilizing the connection of a flexible printed wiring board for electrically connecting a display panel and circuit components mounted on a chassis member, and preventing damage. The present invention relates to a display device.

  In recent years, the demand for information display devices has greatly shifted to flat screen display devices with large screens due to the shift to terrestrial digital broadcasting and the like. One of the flat display devices is a plasma display device. In the plasma display device, elements to be discharged are arranged in a cell shape, two glass substrates are bonded together and sealed, and the discharge elements are discharged in a sealing space, and the phosphor on the glass substrate emits information to emit information. The plasma display (hereinafter referred to as PDP) generates heat during this discharge. The temperature rise due to the heat generation of the PDP not only deteriorates the image quality because it changes the light emission luminance of the phosphor, but also may cause damage to the glass substrate due to local temperature distribution of the glass substrate. For this reason, the heat generated in the PDP is transferred to a metal chassis member having good thermal conductivity through an adhesive high thermal conductive sheet or the like and radiated into the air. The chassis member is fixed on the back side of the glass substrate of the PDP by an adhesive high thermal conductive sheet or the like, but not only the heat dissipation of the PDP but also the strength of the PDP and the circuit board that drives and operates the PDP. It plays a role as a member to be held on the plane side opposite to the fixing plane side.

  Here, the PDP displays information by discharging the discharge electrodes arranged in a cell shape with the address electrodes formed inside and the display electrodes. However, a pulse voltage is applied to the electrodes formed inside the PDP. In order to apply, one end of the flexible printed wiring board is connected and drawn to the outside, and the other end of the flexible printed wiring board is connected to a circuit board placed on the chassis member.

  In these configurations, due to the heat generated during the discharge of the PDP, the temperature of the chassis member thermally connected to dissipate heat rises. As the PDP increases in size, the chassis member also increases in size. The chassis member also has a large amount of distortion caused by the difference in coefficient of thermal expansion. Due to the distortion phenomenon due to the difference in thermal expansion coefficient between the PDP and the chassis member, there is a concern that the wiring having the connection ends and the circuit parts placed on the chassis member may be damaged. Techniques relating to prevention are disclosed in Japanese Patent Application Laid-Open No. 2005-234583 and Japanese Patent Application Laid-Open No. 2006-195177. Further, a technique relating to prevention of damage to circuit components is disclosed in Japanese Patent Application Laid-Open No. 2006-119635.

Japanese Patent Laying-Open No. 2005-234583 JP 2006-195177 A JP 2006-119635 A

  The present invention provides a flat display device that prevents damage to a flexible printed wiring board that electrically connects a PDP held by a chassis member and a circuit board against distortion caused by a difference in thermal expansion coefficient between the PDP and the chassis member. However, there are technical problems to be solved in the above-described conventional technology.

  The plasma display device described in Patent Document 1 prevents circuit damage due to thermal deformation, and realizes a high-quality image so that the circuit board has a linear length relative to the longitudinal length of the wiring connecting the PDP and the circuit board. The ratio of the linear length from one end to the curved portion of the wiring is at least 0.25 or more. However, this wiring damage prevention is intended to cope with the influence of the distortion amount by limiting the length of the wiring. The heat generation state of the plasma display device, the size of the PDP, the arrangement relationship between the PDP and the chassis, etc. Depending on the configuration, the wiring length may be increased. Moreover, since the cause of the damage of wiring is not excluded, there is a concern that the shape to be selected as damage prevention is different in the configuration of the plasma display device.

  The flat display device described in Patent Document 2 has a positional relationship caused by a difference in thermal expansion between the chassis and the panel in a structure in which the chassis for fixing the circuit board to the back of the flat display panel is thermally connected. In order to reduce the burden on the flexible cable caused by changes and prevent the flexible cable from being detached or damaged, the chassis is configured as a plurality of independent chassis, and the circuit board is divided into a plurality of block boards. The block substrate is attached to each of the plurality of chassis with gaps. By dividing the chassis into smaller ones, the amount of distortion due to the difference in thermal expansion coefficient can be dispersed and reduced. However, with regard to the reinforcing effect of the flat display panel as another function of the chassis, the chassis is divided into smaller parts. It has not been studied at all.

  The plasma display device described in Patent Document 3 is formed in a tape carrier package, and damages a driver IC sandwiched between a cover plate thermally connected to the drive IC and a chassis base to dissipate heat generated by the drive IC. In order to prevent this, at least one of the cover plate and the chassis base is formed with a slit around a portion corresponding to the drive IC. Due to the difference in thermal expansion coefficient between the PDP and the chassis base, even when a strain acting force is applied, the portion defined by the slit is prevented from swinging and an excessively strong external force acting on the driver IC is prevented. However, although this technology has the effect of relaxing the pressure in the Z direction on the drive IC to prevent damage to the drive IC, the X direction and Y direction acting on the tape carrier package etc. that packages the drive IC. Corresponding to distortion is not considered.

  In order to solve the above problems, a flat display device of the present invention includes a display panel, a plurality of circuit boards that drive the display panel, and a plurality of chassis members. The display panel is fixed to the display panel via a heat conducting member, and a plurality of circuit boards are fixed on the other plane side of the plurality of chassis members. The display panel and the plurality of circuit boards are provided on the plurality of circuit boards. The plurality of chassis members are configured to have the same number as the number of connectors or less than the number of connectors, and each of the plurality of chassis members is connected to the connector. Flexibility in one or more of the shapes perpendicular to the direction to connect the flexible printed wiring board connected to the connector mounted on each chassis member The size is approximately equal to the planar width shape of the wiring portion of the lint wiring board, and is arranged adjacent to the display panel plane. Adjacent chassis members are spaced apart from each other in thermal expansion. is doing.

  Further, a planar convex side is formed on one of the adjacent sides of the plurality of chassis members arranged adjacent to each other, and a planar side is formed on the adjacent side opposite to the adjacent sides of the plurality of chassis members arranged adjacent to each other. A plurality of chassis members are fixed to the display panel such that a concave side is formed and one convex side of the adjacent chassis member and the other concave side overlap in a plane.

  Furthermore, one of the adjacent sides of the plurality of chassis members arranged adjacent to each other is formed in a step shape, and the adjacent side of the adjacent sides of the plurality of chassis members arranged adjacent to each other is formed in a flat plate shape. The plurality of chassis members are fixed to the display panel such that one step shape of the adjacent chassis members and the other flat plate shape are three-dimensionally overlapped.

  According to the present invention configured as described above, while reinforcing the strength of the display panel, the distortion of the chassis member caused by the difference in thermal expansion coefficient between the display panel and the chassis member due to heat generation is dispersed, and the display panel and the circuit board are connected. It is possible to provide a flat display device capable of preventing damage to the flexible printed wiring board.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a configuration diagram conceptually showing the configuration of the flat display device of the present invention. As shown in FIG. 1, the flat display device 1 has a self-luminous PDP (display panel) 3 inside a housing 2. The display panel 3 has a configuration in which the discharge cell layer 31 is sandwiched between a front glass substrate 32 and a rear glass substrate 33. In the housing 2, a plurality of circuit boards 4 on which circuit parts for driving the display panel 3 and circuit parts for operating the flat display device 1 are placed behind the display panel 3 on the rear glass substrate 33 side. It is equipped with.

  Here, the support state of the display panel 3 and the circuit board 4 inside the housing 2 will be described. A metal chassis member 6 having good thermal conductivity is fixed to the rear glass substrate 33 of the display panel 3 with an adhesive member 5 having high thermal conductivity. The heat generated by the display panel 3 is transferred to the chassis member 6 through the highly heat-conductive adhesive member 5 and is radiated to the air in the chassis member 6. Further, the circuit board 4 is fixed to another plane different from the fixing plane of the display panel 3 of the chassis member 6 via a holding member. A plurality of connectors 7 are mounted on the circuit board 4 on which circuit components for driving the display panel 3 are mounted in order to make electrical connection with the display panel 3. The electrodes drawn from the plurality of connectors 7 and the display panel 3 are electrically connected by a plurality of flexible printed wiring boards 8.

  Here, the chassis member 6 has a length substantially equal to the long side direction (X direction) of the display panel 3 and a plurality of pieces in the short side direction (Y direction) of the display panel 3 on a plane substantially equal to the entire surface of the display panel 3. It is divided into pieces and fixed. Although the chassis member 6 shown in FIG. 1 is shown as being divided into four parts, the number of divisions of the chassis member 6 is such that the position of the connector 7 mounted on the chassis member 6 is minimized and the flexible printed wiring board 8 is arranged. In order to prevent damage, it is preferable to divide the connector 7 as a minimum size that can be placed.

  However, in the case where the flexible printed wiring board 8 in which the connecting portion of the connector 7 is made small and the printed wiring portion of the flexible printed wiring board 8 is wide as shown in the second from the top in FIG. 1 is used. When the shape of the chassis member 6 is formed to the minimum size matching the width of the connector 7 and the adjacent flexible printed wiring board 8 is connected, the gap between the adjacent chassis members 6 becomes wide, and the display panel The heat dissipation effect of 3 and the strength reinforcing effect are hindered. Therefore, the width shape of the divided chassis member 6 in the connection direction of the connector 7 is preferably approximately equal to the width shape in which the wiring portion of the flexible printed wiring board 8 connected to the connector 7 is arranged. Although the reason will be described later, when a plurality of connectors 7 are mounted on the single chassis member 6, the width shape in which the wiring portions of the respective flexible printed wiring boards 8 connected to the respective connectors 7 are arranged. It goes without saying that the size is approximately equal to the size arranged in the same plane. In this state, each adjacent chassis member has a shape having a gap that does not come into contact with each other at the time of displacement due to thermal expansion.

  In FIG. 1, each of the divided chassis members 6 is provided with one connector 7 connected to a circuit component for driving the display panel 3, and the number of connectors 7 is described as four. However, it goes without saying that the number of connectors 7 is not limited to four by mounting the number required for the plasma display device.

  Further, since increasing the number of divisions of the chassis member 6 is not a preferable direction from the viewpoints of component management, manufacturing workability, and the like, the size of the chassis member 6 allows the connector 7 to be mounted and is flexible. The selection may be made on the basis of a situation in which the flexible printed wiring board 8 is not damaged based on the minimum shape that does not hinder the arrangement of the printed wiring board 8. Therefore, a plurality of connectors 7 may be mounted on one divided chassis member 6.

  Here, the circuit component 4 and the circuit board 4 on which the connector 7 is placed are held on the chassis member 6 by screws or the like (not shown). The chassis member 6 also holds another circuit board 4 on which other circuit components such as operating and controlling the plasma display device 1 are mounted.

  The divided chassis member 6 to which the display panel 3 is fixed is supported by a support member 9 that supports the plasma display device 1 itself.

  Next, the divided shape of the chassis member 6 will be described. FIG. 2 is a schematic diagram showing a divided shape of the chassis member that holds the circuit board on which the connector is placed. In FIG. 2, (1) shows a strain state due to thermal expansion in the shape of the chassis member 6 of the present invention, and (2) is in a generally implemented plate-like chassis member. The distortion state is shown in comparison.

Here, the thermal expansion coefficient of glass, which is a representative material of the glass substrate 33 of the display panel 3, is about 8.5 × 10 ⁻⁶ / K. Assuming that the chassis member 5 is an aluminum material, the thermal expansion coefficient is assumed. Since the rate is about 23.0 × 10 ⁻⁶ / K, both members differ in the amount of elongation at a predetermined temperature rise due to the difference in the coefficient of thermal expansion. Therefore, the set positions in the normal temperature state of both ends of the connection of the flexible printed wiring board 8 joined to both members are relative positions at both ends of the connection between the display panel 3 and the connector 7 when the temperature rises due to heat generation of the display panel 3. Deviation will occur. FIG. 3 is a graph illustrating the difference in the amount of relative expansion between the chassis member 6 and the display panel 3 in terms of the amount of distortion of the chassis member 6 in order to easily understand the phenomenon of relative displacement caused by thermal expansion. It is displayed as.

  The shape of the chassis member 6 divided into four in the short side direction (Y direction) of the display panel 3 is that when the length in the short side direction is (l) and the strain at the time of temperature rise is (δl). This is the amount of distortion (δL≈4 × δl) in the length in the short side direction (L≈4 × l) of a single large chassis member. Comparing the two, the strain of each divided chassis member 6 ( The total strain amount (4 × δl) of δl) is about the same amount (δL), but the strain amount (δl) of each chassis member 6 is smaller than the elongation of one large chassis member (δL). > Δl). That is, with respect to the relative displacement amount of the connector 7 placed in the end region of the single large chassis member 6 in the related art, the displacement is achieved by dividing the chassis member 6 and placing the connector 7 thereon. The amount can be suppressed. Further, since the distortion due to the thermal expansion of the chassis member 6 on which the connector 7 is placed is distorted so as to spread in both directions on which the connector 7 is placed, a biased distortion may be applied to the flexible printed wiring board 8. Therefore, it is possible to prevent the flexible printed wiring board 8 from being detached from the connector 7 and from being damaged.

  Here, the shape of the long side direction of the display panel 3 of the chassis member 6 is substantially the same length as that of the single large-sized chassis member in the related art because the flexible printed wiring board 8 is bent and extended. This is because the configuration easily absorbs the influence of the strain amount (δW) due to the thermal expansion of the chassis member 6. Depending on the installation state of the flexible printed wiring board 8, the chassis member 6 is also divided in the long side direction, so that the flexible printed wiring board 8 can be effectively dropped and damaged due to heat generation of the display panel 3. .

  Next, details of the shape of the divided chassis member 6 and the positional relationship between the display panel 3 and the chassis member 6 will be described.

  As shown in FIG. 2, the divided chassis members 6 are arranged and fixed so as to have a gap (d). Since the divided chassis member 6 expands in all directions when the temperature rises with respect to the fixed state at normal temperature, the gap (d) between the adjacent chassis members 6 is at least a displacement amount (display panel 3 due to thermal expansion). It is necessary to make the length larger than the strain amount δl) of the difference between the thermal linear expansion coefficients of the chassis member 6. If the number of divisions of the chassis member 6 is small, the distortion amount (δl) of thermal expansion inevitably increases, so that the gaps (d) need to be widened. When the gap is widened, in the configuration of the chassis member divided in the short side direction of the display panel 3, a portion in the gap (d) is generated as a concern that the display panel 3 is reinforced.

  An embodiment relating to the shape of the divided chassis 6 for coping with the problem of reinforcement of the display panel 3 will be described with reference to FIGS. FIG. 3 is a perspective view schematically showing the corresponding chassis member by a planar shape, and FIG. 4 is a perspective view schematically showing the corresponding chassis member by a three-dimensional shape. In FIGS. 3 and 4, the length (W) in the long side direction, the length (l) in the short side direction, and the gap (d) indicate the relationship with the shape described in FIG.

  First, in the first embodiment shown in FIG. 3, a convex portion 61 having a substantially semicircular shape is formed on the side at an arbitrary position on the side in the long side direction of the divided chassis member 6. ing. The shape of the convex portion 61 reaches the opposite side portion of the divided chassis member 6 disposed adjacently with a gap (d), and further exceeds the side portion of the adjacent chassis member 6 (D ) (D> d). In each divided chassis 6, a concave portion 62 (depth: D) in which the convex portion 61 of the divided chassis 6 disposed adjacent to the side portion opposite to the side portion where the convex portion 61 is formed can be disposed. ). The convex portion 61 and the concave portion 62 are provided at substantially the same position in the long side direction so as to be engaged with each other on a plane. Moreover, this structure forms the length (1) of the short side direction of the chassis member 6 as substantially the same length toward the long side direction, and does not increase the amount of elongation strain due to thermal linear expansion. In addition, the planar engagement arrangement avoids the gap (d) from being linear, and can avoid the inferior reinforcement of the display panel 3.

  Here, FIG. 3 shows only one set of the shape of the convex portion 61 and the concave portion 62, but a plurality of sets may be formed at a predetermined position. Moreover, although the convex part 61 and the recessed part 62 are described as a substantially semicircular shape, it cannot be overemphasized that other shapes, such as an ellipse, a trapezoid, a rectangle, may be sufficient.

  Next, in the second embodiment shown in FIG. 4, the step length slightly larger than the thickness (t) of the chassis member 6 by pressing or the like along the side portion in the long side direction of the display panel 3 of the divided chassis member 6. Convex side-shaped shape 63 having (T) and having a length (D) larger than the gap (d) of the chassis member is provided so as to cover the base portion of the adjacent chassis member 6. That is, the inferior reinforcement of the display panel 3 is reinforced by arranging the divided chassis members 6 adjacent to the gaps between the divided chassis members 6.

  As described above, the chassis member 6 for holding the circuit board 4 and fixing the display panel 3 is divided and formed, and the chassis members are arranged apart from each other. Regardless of the temperature rise, the amount of distortion of the chassis member due to the difference in thermal expansion coefficient between the chassis member 6 and the display panel 3 can be dispersed, and the connector 7 mounted on the chassis member and the display panel 3 are electrically connected. The positional displacement to the connected flexible printed wiring board 8 is suppressed, and it is possible to suppress the drop-out and damage from the connector 7.

  Further, the flat display device 1 is becoming larger and larger. Therefore, the chassis member to which the display panel 3 is fixed is also increased in size. The increase in the size of the chassis members leads to deterioration in workability and large costs due to the increase in the size of the equipment in the production of the chassis members. However, while reinforcing the display panel while dividing the chassis members for large screens, The formation of the chassis member that does not degrade the quality of the flat panel display device can improve the productivity of a large screen.

  As described above, according to the present invention, it is possible to provide a large-screen flat display device with high productivity and reliability.

It is the block diagram which showed notionally the structure of the flat type display apparatus of this invention. It is a schematic diagram which shows the division | segmentation shape of the chassis member holding the circuit board which mounted the connector in this invention. It is a perspective view which shows typically the division | segmentation chassis member corresponding by the planar shape of this invention. It is a perspective view which shows typically the division | segmentation chassis member corresponding by the three-dimensional shape of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Flat display device 2 Case 3 PDP (display panel)
4 Circuit Board 5 Thermal Conductive Member 6 Divided Chassis Member 7 Connector 8 Flexible Printed Circuit Board 9 Support Member

Claims (2)

A display panel, a plurality of circuit boards for driving the display panel, and a plurality of chassis members;
One plane side of the plurality of chassis members is fixed to the display panel via a heat conducting member, and the plurality of circuit boards are fixed to the other plane side of the plurality of chassis members ,
Wherein the display panel and the plurality of circuit boards are electrically connected by a flexible printed circuit board connected to the connector provided on the plurality of circuit boards,
The plurality of chassis members are configured by the same number as the number of connectors or a number smaller than the number of connectors,
Each of the plurality of chassis members, the direction perpendicular to the direction of the shaped connecting the flexible printed wiring board, one connected to the connector provided on the chassis member of the each or a plurality of the said connector The size is approximately equal to the planar width shape of the wiring portion of the flexible printed wiring board, and is arranged adjacent to the display panel plane,
The chassis members arranged adjacent to each other have an interval that does not contact in thermal expansion , and
A planar convex side is formed on one of the adjacent sides of the plurality of chassis members arranged adjacent to each other,
A planar concave side is formed in the adjacent side opposite to the adjacent side of the plurality of chassis members arranged adjacent to each other,
The flat panel display device , wherein the plurality of chassis members are fixed to the display panel so that the one convex-shaped side and the other concave-shaped side of adjacent chassis members overlap in a planar manner . A display panel, a plurality of circuit boards for driving the display panel, and a plurality of chassis members;
One plane side of the plurality of chassis members is fixed to the display panel via a heat conducting member, and the plurality of circuit boards are fixed to the other plane side of the plurality of chassis members,
  The display panel and the plurality of circuit boards are electrically connected by a flexible printed wiring board connected to a connector provided on the plurality of circuit boards,
The plurality of chassis members are configured by the same number as the number of connectors or a number smaller than the number of connectors,
Each of the plurality of chassis members has a shape perpendicular to a direction in which the flexible printed wiring board is connected to the connector, and one or a plurality of the plurality of the chassis members connected to the connectors provided on the chassis members. The size is approximately equal to the planar width shape of the wiring portion of the flexible printed wiring board, and is arranged adjacent to the display panel plane,
The chassis members arranged adjacent to each other have an interval that does not contact in thermal expansion, and
One of the adjacent sides of the plurality of chassis members arranged adjacent to each other is formed in a step shape,
Opposing adjacent sides of the adjacent sides of the plurality of adjacently arranged chassis members are formed in a flat plate shape,
The plurality of chassis members are fixed to the display panel so that the one step shape of the adjacent chassis member and the other flat plate shape overlap three-dimensionally.
A flat display device characterized by that.

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