JP2014142379A - Planar display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a planar display device that prevents dust from entering by bonding a bezel to the display surface side of a liquid crystal display panel through a double-side adhesive tape and bonding a surface light source device to the non-display surface side of the liquid crystal display panel through the double-side adhesive tape, suppresses problems on pasting workability and quality of the double-side adhesive tape, and is excellent in work efficiency and quality.SOLUTION: A thin wall part 61 is formed at each end part of a plurality of tape member pieces 60, the thin wall parts 61 of adjacent tape member pieces 60 are overlapped to construct a frame-like double-side adhesive tape 17, and using the double-side adhesive tape 17, a liquid crystal display panel 12 and a bezel 15, and the liquid crystal display panel 12 and a surface light source device 16 are bonded, respectively.

Description

  The present invention relates to a flat display device in which a double-sided adhesive tape for bonding a flat display panel and a member to be bonded such as a bezel or a surface light source device is improved in a flat display device such as a liquid crystal display device, an organic EL display device, or a plasma display. .

  Currently, flat display devices are widely used in color televisions, personal computers, video display monitors, mobile phones, and the like in terms of thinness and weight reduction and low power consumption. In such a flat display device, the flat display panel is mainly used, and the flat display panel and the flat display panel are irradiated from the back surface or between the flat display panel and the bezel arranged in front of the flat display panel. A configuration is adopted in which a surface light source device is bonded and fixed with a double-sided adhesive tape, and a flat display device using this double-sided adhesive tape is described in Patent Document 1.

JP 2010-60658 A

  In this way, by adhering and fixing the flat display panel and the bezel or between the flat display panel and the surface light source device with a double-sided adhesive tape without any gap, dust from the outside does not enter the flat display device. Is suppressed.

  However, the structure for adhering both without any gap using this double-sided adhesive tape is complicated, and there is a problem that much work is required for the bonding operation.

  The problem to be solved by the embodiment is that it is possible to prevent the intrusion of dust from the outside by eliminating the gap or making the gap narrower with a simple configuration, and workability It is another object of the present invention to provide an excellent flat display device.

  A flat display device according to an embodiment includes a flat display panel having a pair of opposing substrates, and a double-sided adhesive tape having a rectangular frame shape in a plan view for bonding the flat display panel and an adherend, The double-sided adhesive tape is composed of a combination of a plurality of tape member pieces, and a thin wall portion is formed at each end portion of the tape member piece, and the thin wall portions formed at the adjacent tape member piece end portions overlap each other. The flat display device is characterized in that it is superposed on and adhered to the flat display device.

1 is an exploded perspective view schematically showing a flat display device of an embodiment. It is a disassembled perspective view which shows typically the surface light source device which comprises the flat display apparatus of embodiment. It is a disassembled perspective view which shows typically the other structure of the surface light source device which comprises the flat display apparatus of embodiment. It is a fragmentary sectional view showing the flat display device of an embodiment. It is a block diagram which shows the structure of the double-sided adhesive tape which comprises the flat display apparatus of embodiment. It is a block diagram which shows the other structure of the double-sided adhesive tape of embodiment.

  Hereinafter, a flat display device according to an embodiment will be described in detail with reference to the drawings.

  A case where the present invention is applied to a liquid crystal display device employing a liquid crystal display panel as a flat display panel will be described as the flat display device of the embodiment.

  As shown in FIGS. 1 and 4, the liquid crystal display device includes a liquid crystal display panel 12 including a display area 10 and a frame area (non-display area) 11 formed on the outer periphery of the display area 10. On the front surface (viewing side) of the liquid crystal display panel 12, a bezel (adhered body) 15 having an opening 13 at a portion facing the display region 10 and a main body portion 14 at a portion facing the frame region 11 is disposed. Has been.

  On the other hand, a surface light source device (adhered body) 16 is disposed on the back side (non-viewing side) of the liquid crystal display panel 12.

  And between the liquid crystal display panel 12 and the bezel 15, that is, between the frame region 11 and the back surface of the main body 14, and between the frame region 11 of the liquid crystal display panel 12 and the non-irradiation region of the surface light source device 16. The double-sided adhesive tape 17 having a rectangular frame shape in plan view is interposed between the liquid crystal display panel 12 and the bezel 15, and between the liquid crystal display panel 12 and the surface light source device 16, respectively. Is fixed by bonding.

  In this liquid crystal display panel 12, transparent pixel electrodes 21 constituting a display pixel 20 made of indium tin oxide (ITO) or the like are arranged in a matrix on the main surface of a transparent insulating substrate 19 made of a glass material or a synthetic resin material. A plurality of scanning lines 22 are arranged in the row direction of the pixel electrodes 21, and a plurality of signal lines 23 are arranged in the column direction of the pixel electrodes 21.

  Corresponding to the pixel electrode 21, a plurality of TFTs 24 as switching elements are disposed in the vicinity of the intersection position of the scanning line 22 and the signal line 23. In the TFT 24, the scanning line 22 formed along the row direction of the pixel electrode 21 and the gate electrode are connected, and the source electrode or the drain electrode is connected to the signal line 23 formed along the column direction of the pixel electrode 21. The TFT 24 is turned on by a driving voltage supplied from a scanning line driving circuit (not shown) through the scanning line 22, and the signal voltage from the signal line driving circuit (not shown) is supplied to the source / drain of the TFT 24. It operates to apply to the pixel electrode 21 through the passage.

  The pixel electrode 21 is connected in parallel with an auxiliary capacitor (not shown) composed of an auxiliary capacitor line set to a predetermined potential. The TFT 24, the pixel electrode 21, the scanning line 22, and the signal line 23 are connected. Further, an alignment film (not shown) made of polyimide or the like is further provided on the upper surface of the drive lines such as the array substrate 25.

  Further, the counter substrate 26 facing the array substrate 25 includes a transparent insulating substrate 27 formed of a glass material or a synthetic resin material, and a main surface of the transparent insulating substrate 27 facing the array substrate 25. In addition, a black light-shielding film (not shown) is provided in the peripheral portion, and a transparent common electrode 28 made of ITO or the like is provided. An alignment film (such as polyimide) is further formed on the upper surface of the common electrode 28. (Not shown) is provided.

  The insulating substrate 27 surrounded by the light shielding film has three primary color filters (not shown) made of an acrylic material and a black matrix (not shown) for blocking light leakage from the gaps between the wirings. Is provided to constitute the counter substrate 26. These common electrodes 28 are supplied with a driving voltage from a common electrode driving circuit (not shown).

  The array substrate 25 and the counter substrate 26 are arranged to face each other with a predetermined gap, and are bonded to each other through a sealing material (not shown). A liquid crystal member 29 is sealed in the gap. . The thickness of the liquid crystal member 29 is defined by a spacer (not shown) interposed between the array substrate 25 and the counter substrate 26 to constitute the liquid crystal display panel 12. On both outer surfaces of the liquid crystal display panel 12, polarizing plates 18 (see FIG. 4) are attached with an adhesive.

  Further, the surface light source device 16 is disposed outside the polarizing plate 18 on the array substrate 25 side.

  The surface light source device 16 includes a light emitting unit 30 and a front case 31 and a back case 32 that sandwich the light emitting unit 30.

  The surface light source device 16 employs a configuration as shown in FIG.

  That is, referring to FIG. 4 as well, light from a light source 53 including an LED 51 and a reflector 52 arranged on one side surface and mounted on a flexible printed wiring board (FPC) 50 is introduced, and the main plane is viewed. A light guide plate 33 configured as a flat plate that emits as planar light, and an optical sheet 37 such as a diffusion sheet 34, a lens sheet 35, and a polarizing sheet 36 that are sequentially arranged on the output surface side of the light guide plate 33 are provided. Yes.

  The arrangement position of the FPC 50 is not limited to the position shown in the figure, and can be arranged on the lower side of the LED 51 or on the back side of the LED 51 depending on the configuration and specifications of the LED 51.

  On the other hand, a reflection sheet 38 is disposed on the non-light-emitting surface side of the light guide plate 33. The reflection sheet 38, the light guide plate 33, and the optical sheet 37 are collectively accommodated in a synthetic resin frame 39. The surface light source device 16 is configured by sandwiching 39 between the back case 40 and the front case 41. The light emitting unit 30 in FIG. 1 is simply referred to generically as a portion excluding the front case 31 and the back case 32.

  In this surface light source device 16, the optical sheet 37 is constituted by three sheets of a diffusion sheet 34, a lens sheet 35, and a polarizing sheet 36, but any one of the sheets can be omitted. Further, another sheet can be added, and the type and configuration are not particularly limited.

  In the configuration of FIG. 2, the surface light source device 16 is configured by using the frame 39. However, as shown in FIG. 3, the frame 39 is omitted, and the light guide plate is formed by the back case 40 and the front case 31. 33, the optical sheet 37, and the reflection sheet 38 may be held. Here, in order to avoid duplication of description, the same components are denoted by the same reference numerals, and detailed description thereof is omitted.

  One surface side of the double-sided adhesive tape 17 having a rectangular frame shape in a plan view is bonded to the front surface of the surface light source device 16 thus configured, that is, the surface side of the liquid crystal display panel 12 of the front case 31.

  As shown in FIG. 1, the front case 31 includes a frame-shaped main body 41 and an opening through which light emitted from the light guide plate 33 protrudes inward from the main body 41. The optical sheet 37 is in contact with the lower surface of the holding unit 43 and the liquid crystal display panel 12 is placed on the upper surface of the holding unit 43 via the double-sided adhesive tape 17. Yes. In other words, the surface light source device 16 and the liquid crystal display panel 12 are bonded and integrated by the double-sided adhesive tape 17.

  The surface light source device 16 and the liquid crystal display panel 12, and the liquid crystal display panel 12 and the bezel 15 are bonded and fixed by a double-sided adhesive tape 17. As shown in FIG. 5, the double-sided adhesive tape 17 is configured in a rectangular frame shape in plan view from a combination of a plurality of rectangular and strip-like tape member pieces 60-1, 60-2.

  That is, each of the tape member pieces 60-1, 60-2,... Is composed of a base portion formed of a synthetic resin or the like at the center and an adhesive applied to both surfaces thereof. −1, 60-2... On both sides in the longitudinal direction is based on one side so that the thickness is approximately half of the total thickness in the thickness direction of the tape member pieces 60-1, 60-2. .. Are formed.

  These thin-walled portions 61-1, 61-2, ... form the adhesive layer after the thickness of the thin portion is reduced by pressing the end of the base portion with a press before forming the adhesive layer on the base portion. Alternatively, it may be formed by means such as press forming with a pressing machine covered with a non-adhesive member after applying an adhesive to the base portion.

  The thin-walled portions 61-1, 61-2, ... are formed in the middle of the long form before being divided into the individual tape member pieces 60-1, 60-2, and formed in the middle. It is also possible to constitute the tape member pieces 60-1, 60-2,... By cutting at the center positions of the thin portions 60-1, 60-2,.

  The simplest and most cost-effective method of obtaining a tape member piece is to have a surface area equivalent to the area where a plurality of tape member pieces are juxtaposed, and on both sides with a thickness equivalent to the thickness of the thin portion. A large first mother base sheet having an adhesive is prepared, and the adhesive is provided on one or both sides of the mother base sheet that is formed to be small by a length corresponding to the thin portions at both ends. A large second mother base sheet having the same thickness as the mother base sheet is prepared.

  These first and second mother base sheets are arranged so that the adhesive surface side of the second mother base sheet is on the outside (if there is an adhesive on both sides, either side may be used), and The two ends are overlapped and bonded so as to ensure a length corresponding to the thin portion.

  Thereafter, the two mother substrate sheets bonded together are cut in a direction corresponding to the tape member pieces in such a direction that the thin-walled portions are located on both sides, whereby a plurality of individual tape member pieces are obtained in a lump. be able to.

  That is, since the non-overlapping portion of the bonded first and second mother base sheets is only the first mother base sheet, this portion functions as a thin-walled portion, and the thickness thereof is the overlapping portion. Set to half the thickness.

  Whichever form is adopted, there is no problem as long as the thin-walled portions 61-1 and 61-2 are formed at both ends in the longitudinal direction of the tape member pieces 60-1, 60-2.

  About the thickness of this thin part 61-1 and 61-2, as long as it is formed in the thickness of about half of the thickness of tape member piece 60-1, 60-2 ... as mentioned above, It is preferable that the length (width of the thin portion) of the thin portions 61-1, 61-2, ... in the longitudinal direction is substantially the same as the width of the tape member pieces 60-1, 60-2, This is not limited.

  Such tape member pieces 60-1, 60-2,... Are arranged along the frame region 11 of the liquid crystal display panel 12 and in the non-projection region (equivalently, the frame of the liquid crystal display panel 12) in the surface light source device 16. (Corresponding to the region 11). In bonding the individual tape member pieces 60-1, 60-2,..., First, as shown in FIG. 5A, the tape member pieces are formed along the reference side, for example, the long side of the liquid crystal display panel 12. 60-2 is bonded so that the concave surface (stepped portion) 62-2 side of the thin-walled portion 61-2 is opposite to the liquid crystal display panel 12 surface side.

  Subsequently, the thin wall portion 61-1 of the tape member piece 60-1 and the concave surface 62-1 of the tape member piece 60-2 are perpendicular to the tape member piece 60-2. By pressing in the direction of the arrow in the figure so as to be in the same direction, both are bonded as shown in FIG.

  At this time, when the length in the longitudinal direction of the thin portion 61-1 of the tape member piece 60-1 is l1, and the width is w1, the length in the longitudinal direction of the thin portion 61-2 is l2, When the width is w2, it is desirable that the length 11 of the thin portion 61-1 is formed longer than the width w2 of the other tape member piece 60-2.

  Specifically, since the thickness h1 of the thin portion 61-1 is (H1) / 2≈h1 with respect to the thickness (thickness) H1 of the tape member piece 60-1, the tape member piece 60-2 Similarly, the thickness H2 and the thickness h2 of the thin portion 61-2 are set to have a relationship of (H2) / 2≈h2, and to have a relationship of H1 = H2 and h1 = h2.

  Therefore, it is desirable to set the length l1 of the thin portion 61-1 on the overlapping side so as to satisfy the relationship of l1 ≧ 2 × h1 + w2, and preferably satisfy the relationship of l1≈h1 + h2 + w2≈2 × h1 + w2.

  When both thin portions 61-1 and 61-2 are set in such a relationship and they are overlapped, both are bonded and fixed as shown in FIG. 5B. At this time, by satisfying the above-mentioned preferable setting conditions, it is possible to superimpose the overlapping thin portions 61-1 and 61-2 with almost no gap between them. It is possible to set the height to substantially the same height as the height of the tape member pieces 60-1 and 60-2.

  However, even in the overlapping portion of the thin portions 61-1 and 61-2, a gap of about 1 mm is generated as a matter of fact due to problems in the pasting accuracy and the length dimensional accuracy of the tape member pieces 60-1 and 60-2. In some cases, the dimensional accuracy of the thin portions 61-1 and 61-2 needs to be taken into consideration.

  Therefore, it is conceivable to form the length 11 of the thin portion 61-1 on the overlapping side somewhat longer. In such a case, it is difficult to overlap the thin portions 61-1 and 61-2 without a gap, and as shown in FIG. 5B, the thickness of the thin portion 61-1 is near the overlapped portion. It is conceivable that a gap corresponding to the thickness h1 or the thickness h2 of the thin portion 61-2 occurs.

  Here, in order to prevent the intrusion of dust, when considering the case where the ends of the tape member pieces formed in a rectangular shape without the thin portion 61 are simply overlapped, the height of the overlapping portion is considered. However, the thickness of the tape member piece is twice as large as the thickness of the tape member piece, resulting in a step in the overlapped portion, resulting in unevenness in the liquid crystal display panel, which may impair the display quality.

  In addition, there is a problem that a gap corresponding to the thickness of the tape member piece is generated in the vicinity of the overlapping portion. When the thickness of the tape member piece is as thin as about 0.1 mm, the gap generated in the vicinity of the overlapping portion is also about 0.1 mm, which can prevent the intrusion of dust having a size of 0.1 mm or more. It will be possible.

  However, when liquid crystal display panels (cells) of different thicknesses are incorporated into a surface light source device having the same configuration and shared, it is common to absorb this difference in thickness with the thickness of the double-sided adhesive tape. In this case, a double-sided adhesive tape having a thickness of 0.3 mm or more is used. When such a thick double-sided adhesive tape is used, the gap is increased by that amount, and there is a high risk of larger dust entering, and if dust enters, the presence of dust on the display surface is confirmed. There is a problem that the display quality is greatly deteriorated, and in the worst case, it is recognized as a missing item.

  As a method of improving this gap, it is conceivable to abut the end faces of both ends without overlapping the ends of the tape member pieces. There is a high possibility that work time will be required and problems such as variations among workers will occur.

  In the embodiment, the thin-walled portion 61 is formed at the end of the tape member piece 60 constituting the double-sided adhesive tape 17, and the thin-walled portions 61 are overlapped to constitute the double-sided adhesive tape 17 having a rectangular frame shape. Thus, even if a gap is formed in the vicinity of the overlapped portion, the size of the gap is approximately half the thickness of the tape member piece 60, and the size of the dust entering through the gap is also the tape. It becomes possible to suppress to less than half of the thickness of the member piece 60.

  In addition, since the adhesive (adhesive) layer disposed on the tape member piece 60 is exposed on any surface around the gap, dust that tries to pass through the gap is adsorbed on the adhesive layer. Therefore, even if a gap is formed, it is possible to further prevent the passage of dust. If dust adheres to the adhesive layer, the attached dust will play the role of a dike, and the effect of reducing the size of the gap can be expected, further preventing the subsequent entry of dust. It is possible to increase the effect. In other words, the size of dust that can enter is limited to those that are not larger than the size of the gap and that pass without contacting the adhesive layer, and the effect of preventing the passage of the dust is large. It becomes possible.

  In the said embodiment, the position of the recessed part surface 62 of the thin part 61 which is formed in the edge part of each tape member piece 60 and is mutually overlapped is set and overlapped in the same direction. This is intended to improve workability by simply bonding the thin-walled portions 61 while superposing the front and back of the tape member piece 60 in a fixed direction. The front and back surfaces of the adhesive tape 17 can be easily discriminated, for example, a method of changing the color of the adhesive on the front and back surfaces, a different type of tape by forming a notch or the like on the step surface with the thin portion 61 of one tape member piece 60 It is possible to discriminate the side of the thin portion 61 where the concave surface 62 exists by a method of determining that it is the member piece 60, a method of changing the tip shape of the thin portion 61 of one tape member piece 60 to a triangle or a concave shape, etc. Then, as shown in FIG. 6 (a), after aligning so that the concave surfaces 62 face each other, as shown in FIG. 6 (b), the thin portions 61-1 of each other. , 61-2 are bonded together It is also possible to configure.

  In the case of this configuration, it is necessary to determine the position of the thin-walled portion 61 on the concave surface 62 side. If accurate positioning is possible, the thin-walled portion 61-1 on the side to be superimposed is bent and deformed. Therefore, it is possible to greatly reduce the probability of occurrence of a gap due to bending deformation. The generation of the gap in the case of this form is only the gap caused by the displacement based on the amount of displacement between the front and rear and the left and right of the thin portions 61 to be overlapped. Even if it occurs, it is possible not only to obtain the same effect as described in the above embodiment, but also to eliminate at least the cause of the gap accompanying the bending deformation.

  In the above embodiment, a plurality of tape member pieces are combined to form a rectangular frame-shaped double-sided adhesive tape. As this configuration, a tape member piece is bonded to each side and a thin-walled portion is overlapped and bonded at each corner adjacent to each other, but this double-sided adhesive tape is formed in a rectangular frame shape As a configuration to perform, a combination of a pair of L-shaped tape member pieces, a combination of a U-shaped and a linear tape member piece, or overlapping ends in the longitudinal direction without intersecting at the corners. Combinations of the U-shapes are conceivable, but there are no problems with other combinations.

  In addition, the case where the front case and the frame are configured as separate members has been described as the surface configuration device. However, by giving the function of the front case to the frame itself, for example, as shown in FIG. It is clear that it can be rephrased as a front case, or the front case can be rephrased as a frame. In short, when a flat display panel and a surface light source device are bonded with a double-sided adhesive tape, a double-sided adhesive tape is attached to the surface light source device side. Obviously, any name can be used as long as it has an adhesive surface.

  Further, in the surface light source device configured as shown in FIG. 3, it is possible to configure the light guide plate, the optical sheet, the reflection sheet, and the like to be fixed to the front case using an adhesive tape or the like.

  Further, in the above-described embodiment, a case where the present invention is applied to a liquid crystal display device as a flat display device has been described. However, the present invention is not limited to this, and includes, for example, a light emitting element that emits light as a display pixel. If a sealing plate is used as an insulating substrate facing the array substrate, and the two substrates are sealed with a sealing material so that a light emitting element is positioned between the sealing substrate and the array substrate, an organic EL display device or a plasma display It is obvious that the present invention can also be applied to a flat display device in which a flat display panel and a bezel are combined.

  Further, the configurations of the array substrate and the counter substrate can be applied to configurations other than those described above, and other additions and modifications can be made as appropriate without departing from the spirit of the present invention.

12. Liquid crystal display panel (flat display panel)
15 ... Bezel (adhered body)
16... Surface light source device (adhered body)
17 ... Double-sided adhesive tape 60 (60-1, 60-2) ... Tape member piece 61 (61-1, 61-2) ... Thin wall part 62 (62-1, 62-2) ... Recessed surface

Claims (5)

A flat display panel having a pair of opposing substrates;
A double-sided adhesive tape having a rectangular frame shape in plan view for bonding the surface display panel and the adherend;
In a flat display device comprising:
The double-sided adhesive tape is composed of a combination of a plurality of tape member pieces, and a thin portion is formed at each end of the tape member piece, and the thin portions of adjacent tape member pieces are overlapped with each other. A flat display device characterized by being bonded together.   The flat display device according to claim 1, wherein the thin portion is formed to have a thickness that is half the thickness of the tape member piece.   3. The flat display device according to claim 2, wherein the double-sided adhesive tape is overlapped so that thin portions of adjacent tape member pieces are positioned in the same direction.   2. The flat display device according to claim 1, wherein the adherend is a bezel, and both the bezel and the flat display panel are bonded by the double-sided adhesive tape. The said adherend is a surface light source device, Comprising: Both the said flat display panel and the said surface light source device are adhere | attached with the said double-sided adhesive tape.

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