JP2006163742A - Display device with touch panel and manufacturing method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid crystal display device with a touch panel mounted along the image display surface of a liquid crystal display panel, which can prevent the occurrence of ripple-shaped display unevenness caused by pressing operation while making the width of an image non-display region located at the periphery of the image display surface small. <P>SOLUTION: A taper part 11 is provided along the inner edge 11a of a bezel cover 1 so as to form a gap from a liquid crystal display panel 2 on the basis of new knowledge that ripple-shaped display unevenness can be prevented if an inner side is prevented from being directly pressed by sealing material 21. Namely, the taper part 11 in the shape obtained by chamfering an edge at the side of the liquid crystal display panel 2 is provided at the position of an inner edge 11a of the bezel cover 1. In the case of dimensional design, a distance D1+D2 from the foot 11c of the taper part 11 to an inner edge 21a of the sealing material 21 is set smaller than assembling tolerance between them. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a display device with a touch panel in which a touch panel for performing an input operation is attached to a display surface side of a display panel, and a manufacturing method thereof.

  Display devices with touch panels are used in personal computers, personal digital assistants (PDAs), various sales devices, terminal devices, and the like. The touch panel enables an input operation on the display screen by generating an output signal by touching a finger or a pen tip. In addition to the convenience of being able to input while looking at the screen and the advantage that a separate keyboard and mouse can be omitted, anyone can easily input without having to become familiar with keyboard operations, and therefore, it is being widely used.

  A display device with a touch panel generally has a touch panel attached along a display surface of a display panel (Patent Documents 1 to 4). When the display panel has a diagonal dimension of 5 inches or more, a frame-like frame is usually coupled to the peripheral edge of the display panel. The frame-like frame is generally L-shaped in cross section, and is formed of a thickness-direction wall that covers the four peripheral end surfaces of the display panel and an inward flange that covers the edge on the display surface side. When the touch panel is attached along the display surface of the display panel, the peripheral edge portion of the touch panel and the peripheral edge portion of the display panel are overlapped via the inward flange of the frame-like frame (particularly, patent document) 1). Therefore, when a pressing force is applied to the touch panel, the pressing force is partially transmitted to the peripheral portion of the display module.

Therefore, it has also been proposed to provide a cushioning material between the touch panel and the display panel in order to mitigate the influence due to the impact applied to the display device with the touch panel (Patent Document 2).
JP 2003-162375 A JP 2001-56748 A JP 2001-143560 A JP 2000-106297 A

  Recently, display devices with a touch panel have been used for high-end applications such as car navigation devices. That is, a touch panel is attached to a display surface of a display device that performs relatively high-definition display using a TFT (Thin Film Transistor) or the like.

  For example, in a liquid crystal display device with a touch panel, it was observed that a rippled pattern was generated on the image display surface when the user strongly pressed the touch panel. This is presumably because the liquid crystal display panel itself was locally pressed and the gap between the liquid crystal layers was locally non-uniform. Therefore, if the width of the frame region (peripheral image non-display region) of the liquid crystal display device is considerably large, this ripple-like display unevenness is considered to be eliminated because the pressing force is absorbed in this region. . However, on the other hand, particularly in high-end applications, it is required to reduce the installation space as much as possible and to take a large image display area (so-called framed frame).

  The present inventor has intensively studied in view of the above problems. As a result, even if the distance between the outer edge of the image display surface (pixel area) and the inner edge of the sealing material is 2 mm or less, particularly 1.5 mm or less, the inner edge of the frame-shaped frame (tip of the inward flange portion) is It has been found that if the seal material is located outside the inner edge (edge on the pixel region side), the occurrence of rippled display unevenness can be prevented.

  The present invention relates to a display device in which a touch panel is attached to an image display surface of a display panel, and a method for manufacturing the same, and a display defect caused by a pressing operation while reducing the width of an image non-display area at the periphery of the image display surface. Try to provide something that can prevent.

  The liquid crystal display device of the present invention is disposed on the image display surface side of the display panel, a display panel having one main surface as an image display surface, a frame-like frame covering the peripheral edge of the display panel, and the display panel In a display device including a touch panel that sandwiches the frame-like frame between the peripheral portion of the frame, a shape that surrounds the image display surface and cuts a side facing the display panel along an inner edge of the frame-like frame The taper part or thin part is formed, and the base of the taper part or thin part is located outside the image display surface.

  The manufacturing method of the liquid crystal display device of the present invention is arranged on the image display surface side of the display panel having one main surface as an image display surface, a frame-like frame covering the peripheral edge of the display panel, In a display device comprising a touch panel that sandwiches the frame-shaped frame between a peripheral portion of the display panel and the liquid crystal display panel along an inner edge surrounding the image display surface when the frame-shaped frame is manufactured. A tapered or thin part with the opposite side cut off is provided, and in the dimension design, the interval between the base of the tapered part or the thin part and the inner edge of the seal portion is set to a value larger than the assembly tolerance between them. In addition, the distance between the inner edge of the frame-like frame and the inner edge of the seal portion is set to a value smaller than or substantially equal to the assembly tolerance.

  It is possible to prevent the occurrence of display defects associated with the pressing operation while reducing the width of the image non-display area at the periphery of the image display surface.

  Hereinafter, as an embodiment of the present invention, a liquid crystal display device will be described as an example.

  An embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a laminated cross-sectional perspective view schematically showing a main part of the liquid crystal display device of the embodiment, and FIG. 2 is a schematic plan view of the liquid crystal display device of the embodiment. FIG. 3 schematically shows the dimensional configuration of the main part of the liquid crystal display device of the embodiment.

  The liquid crystal display device according to the present embodiment performs, for example, a relatively high-definition image display used in a car navigation device. A TFT (thin film transistor) is arranged for each pixel, and an on pixel and an off pixel are electrically connected. This is an active matrix type display device provided with a switching element that is separated into two and holds a video signal supplied to an on-pixel for a predetermined period.

  In the specific example shown in FIG. 1, the liquid crystal display device 10 includes a backlight, and therefore the liquid crystal display panel 2 is of a transmissive type or a transflective type. In addition, as shown in FIG. 2, the image display screen is a wide type having an aspect ratio of about 1/2, and the diagonal dimension is, for example, 7 inches.

  A light guide plate 41 of a backlight mechanism is accommodated in a rectangular tray-shaped resin frame 42 to form a backlight unit 4, and a rectangular flat display panel 2 is placed thereon (display surface side). Further, a frame-like bezel cover 1 made of a metal plate such as stainless steel or magnesium alloy is placed thereon. The bezel cover 1 is a rectangular frame in which the cross section of each part is L-shaped, and includes a wall 13 in the thickness direction that surrounds the end surfaces of the liquid crystal display panel 2 and the backlight unit 4, and an edge on the display surface side of the wall 13 And an inward flange 12 projecting inwardly from the inside. The bezel cover 1 is disposed such that the inward flange 12 overlaps the peripheral edge of the liquid crystal display panel 2. The touch panel 3 further attached to the display surface side is a rectangular flat plate shape that is substantially equal to the outer dimension of the bezel cover 1 in the illustrated example (FIGS. 1 and 2).

  The liquid crystal display panel 2 is fixed by being narrowly pressed from the front and back sides (up and down in the drawing) by the inward flange 12 and the backlight unit 4 of the bezel cover 1 in the image non-display area 10c outside the pixel area 10a. Yes. In order to reduce the width of the image non-display area 10b as much as possible, the inner edge 11a of the bezel cover 2 is originally designed to be slightly outside along the edge 10b of the pixel area 10a.

  The liquid crystal display panel 2 is generally configured as follows. First, the array substrate 24 and the counter substrate 26 are bonded together via the four-round sealing material 21, and the liquid crystal material 25 is sealed to assemble a liquid crystal cell (display panel body). Next, polarizing plates 23 and 24 are attached from the display surface side and the back surface side, respectively, and a drive circuit system (not shown) is further mounted. This drive circuit system, together with the power supply circuit system of the backlight mechanism, is electrically connected to an external drive / power system through the cable wiring 46 and the socket portion 45 (FIG. 2).

  A frame edge-shaped light shielding film 22 that delineates the four circumferences of the pixel region 10 a is provided in advance as a pattern of a metal layer or a black resin layer on the counter substrate 26 or the array substrate 24 along the inner edge 21 a of the sealing material 21. . The frame edge-shaped light shielding film 22 is disposed so as to partially enter the sealing material 21 in order to reliably prevent light leakage at the periphery of the pixel region 10a. However, when the sealing material 21 is interposed, the reliability of adhesion to the insulating substrate 24 or 26 may generally be lowered, so that the dimension D2 (FIG. 3) to be submerged is relatively small.

  The bezel cover 1 and the resin backlight unit 4 are joined by a screwing or a claw mechanism after being positioned by a positioning jig or the like. In such positioning and joining, some variation in assembly position is inevitable. Therefore, the position of the inner edge 11 a of the bezel cover 1 varies to some extent with respect to the position of the outer edge 22 c of the light shielding film 22 and the position of the inner edge 21 a of the sealing material 21. The position of the inner edge 21a of the sealing material 21 also varies to some extent due to the variation of the application position and the spread of the sealing material even when the sealing material is applied to the counter substrate 26 or the array substrate 24. .

  In this specification, the width of the position variation generated in the normal assembly process is referred to as an assembly tolerance. The terms “dimension” and “distance” refer to dimensions and distances in the direction along the image display surface unless otherwise specified. Furthermore, the words “inside” and “outside” mean the inside and outside as viewed from the center of the liquid crystal display device in the direction along the image display surface.

  In the embodiment, as schematically shown in FIGS. 1 and 3, a tapered portion 11 is provided along the inner edge 11 a of the bezel cover 1. The tapered portion 11 has a shape in which a ridge line portion on the display panel side of the inner edge 11a is chamfered so as to form a gap between the tapered portion 11 and the liquid crystal display panel 2. That is, the taper portion 11 has a surface on the touch panel 3 side (upper surface in the drawing) located in the same plane as the portion of the inward flange 12 other than the taper portion. The inner edge 11a of the bezel cover 1 is an end surface extending in the thickness direction, and the edge on the liquid crystal display panel 2 side forms a boundary with the tapered surface 11b (overhanging inclined surface).

  The tapered portion 11 can be easily created by compression processing, grinding, or the like. Even if compression processing which is the simplest processing method is used, it is possible to avoid the occurrence of a protruding portion on the touch panel 3 side without any problem as long as it is within a dimensional range that is normally required. The compression process can be performed easily and quickly, for example, after punching out an opening for an image display surface from a metal plate material and before or after bending the peripheral edge.

  The base 11c of the tapered portion 11, that is, the boundary between the tapered surface 11b and the non-tapered portion of the bezel cover 1 is positioned outside the inner edge 11a of the bezel cover 1 by the width dimension D1 of the tapered portion 11 (FIG. 3). . Therefore, when the liquid crystal display panel 2 is pressed from the touch panel 3 via the bezel cover 1, the limit to which the pressing force is directly applied is at the root 11 c of the tapered portion 11.

  On the other hand, as described above, according to the knowledge found by the present inventors after trial and error, if the limit to which the pressing force through the bezel cover 1 is applied is outside the inner edge 21a of the sealing material 21, the touch panel Occurrence of ripple-shaped display unevenness due to the pressing of is prevented. With such a positional relationship, it is considered that the pressure on the layer of the liquid crystal material 25 can be avoided and the pressing force is received by the sealing material 21. As described above, it is considered that the distance D3 between the pixel region 10a and the inner edge 21a of the sealing material 21 is considerably small as a premise of such a positional relationship. This distance D3 is usually 2 mm or less, particularly 1.5 mm or less, and is set to 1.0 to 1.3 mm, for example, in the case of a product with a narrow frame.

  In the dimension design of the liquid crystal display device 10, when the distance D2 between the inner edge 11a of the bezel cover 1 and the inner edge 21a of the sealing material 21 set outside thereof is smaller than the assembly tolerance, the inner edge 11a of the bezel cover 1 is set. However, a product located inside the inner edge 21a of the sealing material 21 is generated at a certain rate. However, also in this case, if the distance D1 + D2 obtained by adding the set width dimension D1 of the tapered portion 11 to the design distance D2 between the inner edge 11a of the bezel cover 1 and the inner edge 21a of the sealing material 21 is smaller than the dimensional tolerance. The root of the tapered portion 11 is always located outside the inner edge 21a of the sealing material 21. That is, no pressing force is directly applied to the liquid crystal display panel 3 inside the area where the sealing material 21 is disposed. Therefore, it is possible to prevent the generation of a product having ripple-shaped display unevenness. This is supported by a number of prototype tests as described below.

  On the other hand, as shown in FIGS. 1 and 3, in the dimension design of the embodiment, the outer edge 22 c of the frame-shaped light shielding film 22 is set so as to substantially overlap the base 11 c of the tapered portion 11. Therefore, the dimension in which the bezel cover 1 and the light shielding film 22 overlap (the dimension of the overlap), that is, the distance between the inner edge 11 a of the bezel cover 1 and the inner edge of the light shielding film 21 is substantially equal to the dimension D1 of the tapered portion 11. Therefore, if the dimension D1 of the taper portion 11 is larger than the dimensional tolerance between the taper portion 11 of the bezel cover 1 and the light shielding film 22, the inner edge 11a of the bezel cover 1 and the light shielding film are also affected by variations in the assembly process. No gap that causes light leakage is generated between the two.

  Specific examples of the dimensional configuration in the examples are as follows.

  The plate thickness of the bezel cover 1 is about 0.5 to 1.0 mm, for example, 0.8 mm, and the dimension D1 in the direction along the image display surface in the tapered portion 11 is about 0.5 mm. The set distance D2 between the inner edge 11a of the bezel cover 1 and the inner edge 21a of the sealing material 21 is about 0.3 mm. Accordingly, the set dimension D1 + D2 from the base 11c of the tapered portion 11 to the inner edge 21a of the sealing material 21 is about 0.8 mm. The set dimension D3 from the inner edge 21a of the sealing material 21 to the pixel region 10a is about 1.0 to 1.5 mm.

  On the other hand, in this specific example, the dimensional tolerance between the tapered portion 11 and the inner edge 22a of the sealing material is about 0.5 mm, which is sufficiently smaller than about 0.8 mm of the set dimension D1 + D2. Therefore, the probability that the inner edge 11a of the bezel cover 1 is located inside the inner edge 21a of the sealing material 21 in a product that has undergone a normal assembly process is extremely small or substantially equal to zero.

  In this specific example, the dimensional tolerance between the tapered portion 11 and the light shielding film 22 is about 0.4 mm. Therefore, it is sufficiently smaller than the dimension D1 corresponding to the dimension of the above overlap of about 0.5 mm, and the occurrence of light leakage is also prevented.

  When a large number (n = about 100) of liquid crystal display devices having the same configuration as in this specific example were produced, no occurrence of ripples was observed. Moreover, no light leakage occurred at the peripheral edge.

  Next, another embodiment will be described with reference to FIG.

  In the liquid crystal display device of FIG. 4, a thin portion 11 ′ is provided along the inner edge 11 a of the bezel cover 1 instead of the tapered portion 11. The thin portion 11 ′ has a shape in which the side of the liquid crystal display panel 2 is scraped off like the tapered portion 11, and creates a gap between the thin portion 11 ′ and the liquid crystal display panel 2. In the illustrated example, the thickness in the thin portion 11 ′ is substantially uniform, and a step portion 11 d is formed on the liquid crystal display panel 2 side with a portion other than the thin portion of the inward flange 12. Similar to the case of the tapered portion 11, the upper surface of the thin portion 11 ′ is in one plane that is continuous with other portions of the inward flange 12. Even if such a thin portion 11 ′ is provided, the same effect as that obtained when the tapered portion 11 is provided can be obtained. Further, the thin portion 11 ′ can also be relatively easily manufactured by compression processing, grinding processing, or the like.

  Finally, a comparative example will be briefly described with reference to FIG. No tapered portion or the like is provided near the inner edge 11a of the bezel cover 1, and the entire inward flange 12 has a substantially uniform thickness. Therefore, the pressing force from the touch panel 3 is directly transmitted to the liquid crystal display panel 2 even at the location of the inner edge 11 a of the bezel cover 1.

  In the specific example of the dimension configuration, the set dimension D2 from the inner edge 11a of the bezel cover 1 to the inner edge 21a of the sealing material 21 is about 0.3 mm, which is the same as the specific example of the above-described embodiment. , About 0.5 mm. Therefore, in a large number of products, it is observed that the inner edge 11a of the bezel cover 1 is located inside the inner edge 21a of the sealing material 21 at a certain ratio. In this case, when the touch panel 3 is pressed, a ripple display The occurrence of unevenness was observed. Also in this comparative example, the distance D3 from the inner edge 21a of the sealing material 21 to the pixel region 10a was set to about 1.0 to 1.5 mm as in the specific example of the example.

  In the description of the embodiment described above, a transmissive or transflective display device has been described. However, the same applies to a reflective type display device. Further, although the bezel cover is described as being made of metal, in some cases, an engineering plastic material such as polycarbonate can be used.

  Note that the description of the liquid crystal display panel having no pixel area is omitted, but any liquid crystal display panel that performs matrix image display may be used. The light shielding film pattern in the pixel region has a matrix shape, a stripe shape, or a dot shape corresponding to the switching element arrangement location. An amorphous silicon TFT or a polycrystalline silicon TFT is generally arranged for each pixel, but other types may be used.

  Further, the liquid crystal display panel is taken as an example of the display device, and the ripple-like display failure at the time of pressing has been described. However, the present invention is not limited to this. For example, the display panel is a display of a self-luminous display panel such as an organic EL display panel. It is also possible to employ the present invention as a countermeasure against defects.

It is a lamination | stacking cross-section perspective view which shows typically the principal part of the liquid crystal display device of an Example. It is a typical top view of the liquid crystal display device of an Example. It is a typical lamination | stacking sectional drawing which shows only the relevant member for demonstrating the dimension structure of the principal part in the liquid crystal display device of an Example. FIG. 4 is a schematic cross-sectional view corresponding to FIG. 3 showing a liquid crystal display device according to another embodiment. FIG. 4 is a schematic cross-sectional view corresponding to FIG. 3 showing a liquid crystal display device of a comparative example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Bezel cover 10 Liquid crystal display device 10a Pixel area | region which makes image display surface 11 Tapered part near inner edge of bezel cover 1 11a Inner edge of bezel cover 1 11c Base of taper part 12 Inward flange which comprises bezel cover 1 2 Liquid crystal display panel 21 Seal material 21a Inner edge of seal material 22 Frame edge-shaped light shielding film 22c Outer edge of light shielding film

Claims (9)

A display panel having one main surface as an image display surface, a frame-like frame that covers the peripheral portion of the display panel, and the image display surface side of the display panel are disposed between the peripheral portion of the display panel. In a display device provided with a touch panel that sandwiches a frame frame,
A tapered portion or a thin-walled portion is formed by cutting off the side facing the display panel along the inner edge of the frame-like frame surrounding the image display surface,
The display device, wherein a base of the tapered portion or the thin portion is located outside the image display surface.   2. The display panel according to claim 1, comprising a pair of insulating substrates, a liquid crystal layer sandwiched between the substrates, and a sealing material for sealing the periphery of the liquid crystal layer. Display device. A frame edge-shaped light shielding film that defines the outer edge of the image display surface along the sealing material is provided,
The display device according to claim 2, wherein an inner edge of the frame-shaped frame is located inside an outer edge of the light shielding film.   The display device according to claim 2, wherein an interval between an inner edge of the sealing material and an outer edge of the image display surface is 2 mm or less.   The display device according to claim 1, wherein the frame-shaped frame is made of a metal plate, and the tapered portion is formed by compression processing. A display panel having one main surface as an image display surface, a frame-like frame that covers the peripheral portion of the display panel, and the image display surface side of the display panel are disposed between the peripheral portion of the display panel. In a display device provided with a touch panel that sandwiches a frame frame,
When manufacturing the frame-like frame, along the inner edge surrounding the image display surface, a taper portion or a thin-walled portion formed by scraping the side facing the liquid crystal display panel is provided,
In the dimension design, the interval between the base of the tapered portion or the thin portion and the inner edge of the seal portion is set to a value larger than the assembly tolerance between them, and the inner edge of the frame-shaped frame and the inner edge of the seal portion Is set to a value smaller than or substantially equal to the assembly tolerance. A light shielding film is provided in a frame edge shape so as to define an outer edge of the image display surface along the seal portion,
In the dimension design, the distance between the outer edge of the light shielding film and the inner edge of the frame-like frame set so as to be inside is set to a value larger than the assembly tolerance between them. The manufacturing method of the display apparatus of Claim 6.   8. The method of manufacturing a display device according to claim 6, wherein the frame-shaped frame is manufactured by processing a metal plate, and at this time, the tapered portion or the thin portion is formed by compression processing. The method for manufacturing a display device according to claim 6, wherein in dimension design, an interval between an inner edge of the seal portion and an outer edge of the image display surface is set to 2 mm or less.

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