JP2019056718A - Liquid crystal display device - Google Patents

Abstract

To provide a technology capable of obtaining a sufficient display quality with a simple structure.SOLUTION: A liquid crystal display device 100 includes: a front protective plate 30 including a first principal surface 30a having a bent surface, and a second principal surface 30b having a curved surface; a transparent adhesive member 50 produced by pasting display surfaces 10a of a plurality of display panels 10 on the first principal surface 30a in the state in which the display regions of the display surfaces 10a of the display panels 10 are made adjacent to each other. The front protective plate 30 is made of a single material, and the transparent adhesive member 50 is disposed so as to be connected to each of the adjacent display regions and to a region between the adjacent display regions.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a liquid crystal display device, and more particularly to a liquid crystal display device capable of displaying an image on a curved screen.

  A liquid crystal display device, which is a flat display device, is used in portable information devices represented by personal computers, taking advantage of its light weight, thinness, and low power consumption.

  Liquid crystal display devices include various types of liquid crystal panels, backlight units, and liquid crystal display devices in which liquid crystal is sandwiched between a pair of substrates in which an array substrate having pixel electrodes and a color filter substrate having a common electrode are bonded to each other. The circuit includes a circuit and a power source for supplying an electric signal, and a housing for housing them. The liquid crystal display device changes the molecular orientation direction of the liquid crystal by applying a voltage between the pixel electrode and the common electrode, and displays the image by controlling the transmittance when the light from the backlight passes through the liquid crystal. I do.

  In general, as a substrate constituting the array substrate and the color filter substrate, for example, a parallel plate substrate having a planar surface (hereinafter also referred to as “planar substrate”) is used. On the other hand, in recent years, from the viewpoint of design, it is required to display an image on a curved screen by, for example, bending a flat substrate used in a liquid crystal display device with an arbitrary curvature. In response to such demands, various technologies such as a technology that applies a flexible material such as plastic to a substrate, a technology that thinly processes a glass substrate, and deforms and fixes the substrate and thus the liquid crystal display device into a curved shape. Has been proposed.

  For example, a liquid crystal display device using a casing having a side that is higher in rigidity than a liquid crystal panel and has a curved groove that holds the curvature of the liquid crystal panel, or a frame that sandwiches the liquid crystal panel together with a backlight unit or the like A liquid crystal display device having a curved shape has been proposed.

  However, these liquid crystal display devices have a problem that display unevenness occurs around the four corners of the liquid crystal panel. Although measures against this problem have been proposed, in any of the measures, there is a case where a display defect may partially occur, and there is a problem that the frame portion becomes large in order to hide the display defect. In addition, when a large-screen liquid crystal panel is bent, a positional shift occurs in the bending direction due to the difference between the curvature radius of the array substrate and the curvature radius of the color filter substrate, and display defects such as light leakage occur. There is a problem.

  These problems are problems that occur when a parallel flat liquid crystal panel is curved. For example, Patent Literature 1 discloses a technique for displaying a curved image without causing problems due to the bending.

  For example, Patent Document 1 includes a plurality of flat display elements arranged at a constant angle, and an optical element arranged in the vicinity of a region of adjacent display elements, thereby providing a non-planar shape. A display device having the display surface is disclosed. As the optical element, for example, an optical fiber that optically transmits image light incident on the display element to a non-planar exit surface is used. Furthermore, in order to make it difficult to visually recognize the joint (boundary) between the display elements, a film covering the joint of the optical fibers is attached.

  Further, for example, Patent Document 2 discloses a technique for making a joint between display elements inconspicuous by connecting a plurality of display elements with a sheet-like member or a transparent support substrate with a transparent adhesive. ing.

  Further, for example, in Patent Document 3 and Patent Document 4, a portion including an end portion between display elements is filled with an adhesive, and the refractive index of the adhesive is made equal to the refractive index of the substrate of the display element. Has been disclosed.

Japanese Patent No. 5237437 JP 2011-128192 A JP 2004-191608 A Japanese Patent Laid-Open No. 2002-6679

  However, in the technique of Patent Document 1, since there are many constituent members, there is a problem that the manufacturing process becomes complicated and expensive. Further, since the straightness of light of the optical fiber used for the optical element is high, there is a problem that the angle of the image seen from the optical fiber is different and the display quality is lowered. Moreover, in the technique of patent document 2, since a support substrate is bent and used, there exists a problem that the bent part tends to deteriorate, and as a result, a joint is conspicuous and display quality falls.

  Furthermore, if the gap between the display elements is narrowed in the techniques of Patent Document 3 and Patent Document 4, bubbles are likely to be generated when the adhesive is filled. Since the bubbles cause optical non-uniformity, there are problems such as deterioration in display quality and manufacturing yield.

  Therefore, the present invention has been made in view of the above problems, and an object thereof is to provide a technique capable of obtaining a good display quality with a simple structure.

  The liquid crystal display device according to the present invention corresponds to a plurality of display panels each having a flat display surface, a first main surface including a bent surface composed of a plurality of flat surfaces, and a bent portion of the bent surface. A front protective plate having a second main surface opposite to the first main surface, including a curved surface provided, and a display area for displaying an image among the display surfaces of each display panel A transparent adhesive member in which the display surfaces of the plurality of display panels and the plurality of surfaces of the first main surface are bonded together in a state of being adjacent to each other. The front protective plate is made of a single material, and the transparent adhesive member is continuously disposed in each of the adjacent display areas and in an area between the adjacent display areas.

  According to the present invention, the front protective plate is made of a single material, and the transparent adhesive member is continuously disposed in each of the adjacent display areas and the area between the adjacent display areas. Thereby, a favorable display quality can be obtained with a simple structure.

1 is a perspective view showing a configuration of a liquid crystal display device according to Embodiment 1. FIG. 1 is a cross-sectional view illustrating a configuration of a liquid crystal display device according to Embodiment 1. FIG. 5 is a cross-sectional view showing the method of manufacturing the liquid crystal display device according to Embodiment 1. FIG. FIG. 3 is a front view illustrating the method for manufacturing the liquid crystal display device according to the first embodiment. FIG. 6 is a rear view showing the method of manufacturing the liquid crystal display device according to the first embodiment. 5 is a cross-sectional view showing the method of manufacturing the liquid crystal display device according to Embodiment 1. FIG. 5 is a cross-sectional view showing the method of manufacturing the liquid crystal display device according to Embodiment 1. FIG. It is sectional drawing which shows the structure of a related liquid crystal display device. It is sectional drawing which shows operation | movement of a related liquid crystal display device. FIG. 4 is a cross-sectional view showing the operation of the liquid crystal display device according to Embodiment 1. It is sectional drawing which shows the structure of the liquid crystal display device which concerns on a modification. 6 is a cross-sectional view illustrating a configuration of a liquid crystal display device according to Embodiment 2. FIG. 10 is a cross-sectional view showing the method of manufacturing the liquid crystal display device according to Embodiment 2. FIG. 10 is a cross-sectional view showing the method of manufacturing the liquid crystal display device according to Embodiment 2. FIG. FIG. 11 is a rear view showing the method for manufacturing the liquid crystal display device according to the second embodiment. 10 is a cross-sectional view showing the method of manufacturing the liquid crystal display device according to Embodiment 2. FIG. 10 is a cross-sectional view showing the method of manufacturing the liquid crystal display device according to Embodiment 2. FIG. 6 is a cross-sectional view showing an operation of the liquid crystal display device according to Embodiment 2. FIG. 6 is a cross-sectional view showing an operation of the liquid crystal display device according to Embodiment 2. FIG. 6 is a cross-sectional view illustrating a configuration of a liquid crystal display device according to Embodiment 3. FIG. FIG. 11 is a rear view showing the method for manufacturing the liquid crystal display device according to the third embodiment. FIG. 10 is a cross-sectional view showing the operation of the liquid crystal display device according to the third embodiment. FIG. 10 is a cross-sectional view showing the operation of the liquid crystal display device according to the third embodiment.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description, components having the same or similar functions are denoted by the same names and symbols. Detailed description of the components once described may be omitted as appropriate.

  In addition, the dimensions, materials, shapes, relative arrangements, and the like of the constituent elements exemplified in the embodiments are appropriately changed depending on the configuration of the apparatus to which the present invention is applied and various conditions. Are not limited to those examples. Moreover, the dimension of each component in each figure may differ from an actual dimension.

<Embodiment 1>
FIG. 1 is a perspective view showing a configuration of the liquid crystal display device 100 according to the first embodiment, and FIG. 2 is a cross-sectional view showing the configuration. The liquid crystal display device 100 is applied to, for example, a monitor of a PC (Personal Computer), a mobile terminal such as a PDA (Personal Digital Assistant), a game machine, a television receiver, a car navigation device, an in-vehicle monitor, and the like.

  The liquid crystal display device 100 includes two (plural) display panels 10, a front protective plate 30, a printing layer 40, and a transparent adhesive member 50. Although not shown, the liquid crystal display device 100 includes a backlight unit, flexible wiring, an adhesive tape and screws for fixing the display panel 10 in addition to these components.

<Display panel 10>
Each display panel 10 includes a rectangular first substrate, a rectangular second substrate disposed closer to the viewer than the first substrate, and a liquid crystal sandwiched between the first substrate and the second substrate. Is provided. Each display panel 10 is a liquid crystal panel including a polarizing plate 21 attached to the surface opposite to the liquid crystal of the first substrate and a polarizing plate 20 attached to the surface opposite to the liquid crystal of the second substrate. is there.

  Each of the plurality of display panels 10 configured in this manner has a flat display surface 10a capable of displaying an image. The display surface 10a defines a display area in which a plurality of pixels are arranged and an image can be displayed. In the first embodiment, a rectangular region that is the same as the polarizing plates 20 and 21 in a plan view or a rectangular region that is smaller than the polarizing plates 20 and 21 is applied to the display region (not shown). A backlight (not shown) is disposed near the surface of the display panel 10 opposite to the display surface 10a.

  A polarizing plate 20 is attached to one surface (display surface 10a) of the display panel 10, and a polarizing plate 21 is attached to the other surface. For example, the polarizing plates 20 and 21 may be polarizing films or polarizing plates. A hard coat layer or an antiglare layer may be provided on the surfaces of the polarizing plates 20 and 21 as appropriate.

<Front protective plate 30>
The front protective plate 30 is a transparent plate that hardly absorbs visible light. The front protective plate 30 is made of a single material, and includes, for example, a glass plate, a laminated glass, a resin plate (for example, a polycarbonate-based resin, an acrylic resin) whose strength is improved by using an ion exchange method or an air cooling strengthening method. Resin plate such as a resin based on cycloolefin resin).

  The front protective plate 30 has a first main surface 30a and a second main surface 30b opposite to the first main surface 30a.

  The first major surface 30a includes a bent surface composed of two surfaces 30a1 and 30a2 (a plurality of planar surfaces). For example, one side of the surface 30a1 and one side of the surface 30a2 are connected at an angle of about 90 to 170 degrees, so that a bent surface that is bent at the bent portion 31 is formed. The display surfaces 10a of the two display panels 10 are bonded to the two surfaces 30a1 and 30a2 of the first main surface 30a by the transparent adhesive member 50, respectively. In the first embodiment, the area of the first main surface 30a is larger than the total area of the display surfaces 10a of the two display panels 10. In the first embodiment, the number of display panels 10 is two, but may be three or more.

  Second main surface 30b includes a curved surface provided corresponding to bent portion 31 of the bent surface of first main surface 30a. The second main surface 30b is a non-planar image display surface for viewing an image, which is disposed on the side (observer side) viewing the image from the display panel 10. The second main surface 30b is subjected to an anti-glare process, an anti-reflection process, a hard coat process for preventing scratches, and the like as necessary to improve visibility.

  In the first embodiment, the front protective plate 30 viewed from the viewpoint 1 shown in FIG. 2 is assumed to be rectangular as shown in FIG. However, the shape is not particularly limited, and may be, for example, a triangle shape, an n-corner shape (n is an integer of 5 or more), a shape including an arc, or the like.

  Moreover, the shape of the display panel 10 and the transparent adhesive member 50 can also use a desired shape similarly to the shape of the front protective plate 30. The touch sensor may be attached in advance to the second main surface 30b or the first main surface 30a of the front protective plate 30 via a transparent adhesive or the like. The touch sensor generally uses a film substrate or a glass substrate, but is not particularly limited as long as it has a touch sensor function. When the touch sensor is attached to the second main surface 30b, the surface of the touch sensor is hard-coated for anti-glare treatment, anti-reflection treatment, anti-fouling treatment and scratch prevention for improving visibility. Processing or the like is performed as necessary.

<Print layer 40>
The print layer 40 may or may not be disposed on the first main surface 30a or the second main surface 30b of the front protective plate 30. The presence or absence of the print layer 40 is not particularly limited. The printed layer 40 is a layer for decoration (for decoration), for example, but is not limited to decoration (for decoration), and may be a layer for other purposes. The print layer 40 is made of, for example, a material that almost shields light having a wavelength in the visible region, or a paint that includes a colorant pigment. More specifically, the printing layer 40 is made of, for example, an acrylic resin blended with carbon black. In this case, the color of the print layer 40 is black or the like, but the color of the print layer 40 may be a color other than black having light shielding properties.

  The print layer 40 is disposed according to the display area of the display panel 10, and is disposed in a closed loop surrounding the display area, for example. From the viewpoint of design, the positions of the end of the element that displays the image of the display panel 10 (end of the display area) and the open end of the print layer 40 (open end 41 and 42 in FIG. 4). It is preferable to apply a size that minimizes the difference between the two to the dimension of the printing layer 40. The printed layer 40 only needs to satisfy desired performance in terms of design properties, light shielding properties, and the like, and the formation method is not particularly limited. The print layer 40 is formed, for example, by applying a resin using a screen printing method.

  The thickness of the printing layer 40 is generally about 3 to 70 μm, for example, but the thickness design is changed according to the intensity of the light source to be shielded from light. For example, when the color of the printing layer 40 is other than black, the thickness of the coating film of the printing layer 40 is preferably about 10 to 70 μm so that sufficient light shielding properties can be obtained. For example, when the color of the printing layer 40 is black, the thickness of the coating film of the printing layer 40 is preferably about 3 to 40 μm. In addition, when forming the printing layer 40 comparatively thick, it is preferable to form the printing layer 40 by lamination | stacking of a film | membrane from points, such as design property and light-shielding property. In the case where the printing layer 40 is formed by stacking films, problems relating to design properties such as the occurrence of pinholes when foreign matter is present can be suppressed. For this reason, the printing layer 40 can be produced stably with a high yield.

<Transparent adhesive member 50>
The transparent adhesive member 50 has translucency. The transparent adhesive member 50 includes the display surfaces 10a of the two display panels 10 and the first main surface 30a of the front protective plate 30 in a state where the above-described display areas of the display surfaces 10a of the display panels 10 are adjacent to each other. The two surfaces 30a1 and 30a2 are bonded to each other. The transparent adhesive member 50 is continuously disposed in each of the adjacent display areas and in an area between the adjacent display areas. According to the transparent adhesive member 50 configured as described above, it is possible to suppress a reduction in image display quality as will be described later.

  The transparent adhesive member 50 may be formed of one layer or a plurality of layers. For example, the transparent adhesive member 50 may be formed by sticking a transparent adhesive sheet that has been processed into a sheet shape, or a plurality of layers (transparent adhesive) may be substantially uniformly surfaced with a predetermined thickness by a slit coating method. You may form by forming in a shape. In the first embodiment, the transparent adhesive member 50 is described as being formed of a single layer of transparent adhesive sheet.

  The refractive index of the transparent adhesive member 50 is substantially the same (substantially the same) as the refractive index of the front protective plate 30. According to such a configuration, it is possible to suppress a reflection and a decrease in transmittance due to different refractive indexes, and thus it is possible to suppress a decrease in display quality.

  The transparent adhesive member 50 is made of a transparent adhesive resin. For example, the transparent adhesive member 50 is made of a highly transparent material such as acrylic, silicone, or urethane. Although the formation method and thickness of the transparent adhesive member 50 are not specifically limited, it is suitably adjusted according to other structural members. For example, one type or a plurality of types of ultraviolet curable adhesive resins may be used as the adhesive resin of the transparent adhesive member 50. Alternatively, the adhesive resin of the transparent adhesive member 50 may be, for example, a thermosetting adhesive resin or an adhesive resin that uses both thermosetting and ultraviolet curable. However, since thermosetting pressure-sensitive adhesive resins are limited in how they are stored and handled during production, it is assumed that UV-curable pressure-sensitive adhesive resins are often used.

  In the first embodiment, as described above, one adhesive sheet is used as the transparent adhesive member 50. In this case, the storage elastic modulus measured under the conditions of a temperature of 25 degrees and a frequency of 1 hertz was on the order of 0.1 to 1 megapascal. By the way, in order to reduce the elastic modulus that causes display unevenness when bonded to the display panel 10 or to relieve the stress generated by thermal deformation of the display panel 10, the transparent adhesive member 50 has a high value. Flexibility is required. Further, when the flexibility of the transparent adhesive member 50 is low, it is difficult to adhere at the interface with the polarizing plate 20 of the display panel 10, and there is a problem that bubbles are generated and the bubbles are visually recognized. For these reasons, the transparent adhesive member 50 needs high flexibility. It should be noted that the flexibility of the transparent adhesive member 50 is appropriately adjusted so that the flexibility is suitable depending on the size and type of the display panel 10 and other components.

<Manufacturing method>
Next, a detailed configuration of the liquid crystal display device 100 according to the first embodiment and a manufacturing method thereof will be described with reference to FIGS. 3, 6, and 7 are cross-sectional views illustrating the manufacturing method. FIG. 4 is a front view of the image display surface of the liquid crystal display device 100 as viewed from the viewpoint 1 in FIG. FIG. 5 is a back view of the image display surface of the liquid crystal display device 100 as viewed from the viewpoint 2 in FIG. 2 in the direction of the arrow.

  In the first embodiment, the front protective plate 30 is made of a single material made of only acrylic resin and is manufactured by an injection molding method. The material of the front protective plate 30 is preferably a transparent single material having a light transmittance of 80% or more. However, the type of the material is not particularly limited. For example, a polycarbonate resin, a cycloolefin resin, or the like should be used. You can also. Moreover, there is no restriction | limiting in particular also in the preparation methods of the front surface protection board 30, Other shaping | molding methods, such as cutting, extrusion molding, and compression molding, can also be used. However, from the viewpoint of the optical characteristics of the liquid crystal, an appropriate preparation method is selected for the front protective plate 30 so that optical anisotropy does not occur within a range in which the optical characteristics of the liquid crystal do not change. Optimized fabrication conditions are used.

  As described above, by configuring the front protective plate 30 from a single material, the refractive index of an arbitrary portion of the front protective plate 30 becomes constant. For this reason, generation | occurrence | production of the optical boundary which produces unnecessary reflection can be suppressed, and display quality can be improved.

  As shown in FIG. 3, the first main surface 30a of the front protective plate 30 includes a bent surface formed of two planar surfaces 30a1 and 30a2 connected at a constant angle (for example, 120 degrees). . That is, the first main surface 30a is bent at an angle of 120 degrees at the bent portion 31. However, the number of the first main surface 30a is not limited to two, and there may be a plurality of surfaces. When there are three or more surfaces of the first main surface 30a, a plurality of bent portions 31 are formed. In addition, the shape of the bent portion 31 is not a square shape but may be an arc shape having a radius of curvature of about 0.5 to 5 mm, which is smaller than the curved surface of the second main surface 30b, due to the influence of manufacturing accuracy.

  The second main surface 30b of the front protective plate 30 includes a curved surface that is recessed with a uniform curvature radius (for example, 500 mm) toward the bent portion 31 of the first main surface 30a. In addition, there is no restriction | limiting in particular in the curvature radius of the curved surface of the 2nd main surface 30b, and the uneven | corrugated direction of the curved surface. For this reason, a desired curvature radius according to the application and design of the liquid crystal display device 100 is used. Note that the second main surface 30b may be formed by appropriately combining a plurality of curved surfaces of arcs having a plurality of radii of curvature, a plurality of curved surfaces in an uneven direction, and a flat surface.

  A printed layer 40 is formed on the front protective plate 30. As shown in FIG. 4, the printing layer 40 is formed around the first main surface 30 a of the front protective plate 30 and in the central portion, and has two closed loop shapes. As a result, the printing layer 40 is provided with two openings. In FIG. 4, the print layer 40 is located on the back side of the front protective plate 30, but the print layer 40 is illustrated because the front protective plate 30 is transparent.

  The opening end portions 41 and 42 of the printing layer 40 are respectively arranged outside the display area of the display panel 10, and the opening of the printing layer 40 is larger than the display area of the corresponding display panel 10. The printed layer 40 is also disposed on both side surfaces 30c of the front protective plate 30 (the front and rear surfaces of the front protective plate 30 in FIG. 2). In addition, as a material of the printing layer 40, for example, an acrylic paint blended with light-shielding carbon black is applied.

  Next, while applying a certain pressure using a rubber roller, the transparent adhesive member 50 is attached to the first main surface 30a of the front protective plate 30 as shown in FIG. 3 (step 1). The transparent adhesive member 50 is, for example, an acrylic sheet that is a plate-shaped, semi-curable transparent adhesive sheet having a thickness of 250 μm. When the transparent adhesive member 50 has semi-curability, when the front protective plate 30 is attached, the step of the printed layer 40 can be embedded because the transparent adhesive member 50 is highly flexible, and the display panel 10 is attached. Later, since the transparent adhesive member 50 can be cured by UV or heat, long-term reliability can be improved. For this reason, applying a semi-curing member to the transparent adhesive member 50 is effective for products that require high display quality and long-term reliability. However, as long as the reliability required for the product is sufficiently satisfied, the transparent adhesive member 50 may not have semi-curing characteristics. Moreover, there is no restriction | limiting in particular in the method affixed on the front surface protection board 30, a pressure, the affixing speed, etc., and it adjusts suitably according to the softness | flexibility, thickness, etc. of the transparent adhesive member 50.

  Furthermore, there is no restriction | limiting in particular also about the formation method and thickness of the transparent adhesive member 50, and it adjusts suitably according to another structural member. For example, after a transparent adhesive resin is formed into a surface with a thickness of 250 micrometers by a slit coating method, the transparent adhesive resin is irradiated with ultraviolet light having an integrated light amount of 0.3 Joule / square centimeter from the second main surface 30b side. Then, the transparent adhesive member 50 may be formed by temporary curing at a curing degree of 50% or more. There is no restriction | limiting in particular in the hardening degree of temporary hardening, It determines suitably according to the size of the transparent adhesive resin to be used, the restriction | limiting of processing time, the front surface protection board 30 and the display panel 10 to be bonded together.

  In addition, before affixing the transparent adhesive member 50, ozone treatment, plasma treatment, etc. generally known as wettability improvement processing are generally performed on the surface of the front protective plate 30 and the printing layer 40 on which the transparent adhesive member 50 is affixed. The process of may be implemented.

  As shown in FIG. 5, the transparent adhesive member 50 is pasted so as to cover the opening end portion 41 and the opening end portion 42 of the printing layer 40 without any seam. That is, the transparent adhesive member 50 which is one adhesive sheet is affixed so that the opening edge part 41 and the opening edge part 42 of the printing layer 40, and the printing layer 40 of the center part may be covered. Thereby, the transparent adhesive member 50 is continuously formed in the display area of the two adjacent display panels 10 and the area between the display areas of the two display panels 10. Therefore, as shown in FIG. 5, the peripheral edge 501 of the transparent adhesive member 50 is disposed on the print layer 40 in the back view, and the peripheral edge 401 of the print layer 40, the open end 41 and the open end 42. Between the two.

  Next, the some display panel 10 is bonded together to the 1st main surface 30a which affixed the transparent adhesive member 50 among the front surface protection plates 30. FIG. In the first embodiment, two display panels 10 are bonded to the two surfaces 30a1 and 30a2 by one transparent adhesive member 50. The bonding is performed by aligning the two display panels 10 and the two surfaces 30a1 and 30a2 to which the transparent adhesive member 50 is bonded in a low pressure environment of about 100 Pascals, and applying the pressure of about 1 MegaPascal. I stuck together.

  In this manner, as shown in FIG. 6, a structure in which the display panel 10 and the front protective plate 30 are bonded together is obtained (step 2). Note that the degree of vacuum and the pressure at the time of bonding are not particularly limited, and the pressure is determined according to, for example, the performance of the apparatus to be used and the processing time, the size of the display panel 10 and the front protective plate 30 to be bonded. It is decided appropriately. There is no particular limitation on the pressing time and the pressure change during pressing. These time and change are, for example, the performance of the apparatus to be used and the processing time, the display panel 10 to be bonded, and the front protective plate 30. It is determined appropriately according to the size. When bonding in a low pressure environment, the display panels 10 may be bonded one by one.

  Also, there is no particular limitation on the method of attaching, and for example, a method of attaching the display panel 10 to the front protective plate 30 by warping the front protective plate 30 in the atmosphere while aligning can be used. However, since the transparent adhesive member 50 may be deformed when pasting while the front protective plate 30 is warped, a method of pasting in a low pressure environment is preferable.

  Then, the process which lose | disappears the bubble which remain | survives after bonding by pressure defoaming process is performed. The pressure defoaming treatment is not necessary when bubbles do not remain after bonding, but bubbles may or may not come out due to manufacturing errors, so whether or not bubbles remain, It is preferable to perform a pressure defoaming treatment for the stability of production. In the pressure defoaming process, for example, a process of heating at 50 ° C. was performed for about 30 minutes while pressurizing to 5 MPa. The pressure defoaming treatment conditions are not particularly limited, and are appropriately determined according to the flexibility of the transparent adhesive member 50, the sizes of the display panel 10 and the front protective plate 30, and the like.

  Thereafter, as shown in FIG. 7, the transparent adhesive member 50 is fully cured by irradiating from the second main surface 30 b side of the front protective plate 30 with ultraviolet light 60 having an integrated light quantity of 3 Joules / square centimeter. Then, after the main curing, the side surface of the transparent adhesive member 50 is irradiated with ultraviolet light having an integrated light quantity of 3 Joules / square centimeter as described above, and is not cured by being blocked by the printing layer 40 during the main curing. The part is also cured (step 3). In addition, ultraviolet irradiation is not implemented when the adhesive sheet which is not semi-curable is used for the transparent adhesive member 50, or when a thermosetting adhesive sheet or a transparent adhesive resin is used. Further, the irradiation of the ultraviolet light to the side surface of the transparent adhesive member 50 is carried out when a transparent adhesive of a type that cures even if the printing layer 40 is present at the time of main curing is used for the transparent adhesive member 50. It does not have to be. In addition, the order of the irradiation of the ultraviolet light for the main curing and the irradiation of the ultraviolet light to the side surface of the transparent adhesive member 50 may be switched. Thus, the liquid crystal display device 100 shown in FIGS. 1 and 2 is completed.

  The display state of the liquid crystal display device 100 according to the first embodiment thus manufactured and the display state of the liquid crystal display device related thereto (hereinafter referred to as “related liquid crystal display device”) were compared and evaluated.

  FIG. 8 is a cross-sectional view showing the configuration of the related liquid crystal display device 200. The related liquid crystal display device 200 is different from the liquid crystal display device 100 according to the first embodiment in the shape of the transparent adhesive member 50. Specifically, the related liquid crystal display device 200 includes two transparent adhesive members 50 that are spaced apart from each other, and one side of each transparent adhesive member 50 is in contact with the printed layer 40 of the bent portion 31 of the front protective plate 30. Are arranged as follows.

  FIG. 9 shows the direction of travel of the stray light 80 that is the backlight light of the display panel 10 and the external light from the image display surface of the front protective plate 30 (solid line arrows), and the connection, for the related liquid crystal display device 200. It is sectional drawing which shows the advancing direction (broken arrow) of the light 90 corresponding to a certain bright line. FIG. 10 is a cross-sectional view similar to FIG. 9 relating to the liquid crystal display device 100 according to the first embodiment.

  As shown in FIG. 9, in the related liquid crystal display device 200, the stray light 80 reaches the end of the transparent adhesive member 50 in the vicinity of the bent portion 31 of the front protective plate 30, and then is reflected or scattered at the end. The observer reaches 90 as 90. As a result, the bright line is easily visually recognized by the observer.

  On the other hand, as shown in FIG. 10, in the liquid crystal display device 100 according to the first embodiment, one transparent adhesive member 50 is seamlessly attached to the front protective plate 30, and the front protective plate There is no end portion of the front protective plate 30 in the vicinity of the bent portion 31 of the 30. For this reason, it can suppress that an observer visually recognizes a bright line, and can obtain a substantially favorable display quality.

<Modification>
In the first embodiment, the transparent adhesive member 50 is exposed from the outline of the display panel 10 as viewed from the viewpoint 2 side in FIG. If the transparent adhesive member 50 is exposed, dust, foreign matter, and the like may be attached, which may affect long-term reliability.

  Therefore, as shown in FIG. 11, the liquid crystal display device 100 may further include a protective cover 70. The protective cover 70 covers the portion of the transparent adhesive member 50 that is exposed from the outline of the display panel 10 and is in contact with the bent portion 31. For example, the protective cover 70 is a region other than the display image of the display panel 10 in the region covering the vicinity of the bent portion 31 of the front protective plate 30, that is, between the opening end 41 and the opening end 42 of the printing layer 40. Arranged in the area. According to such a protective cover 70, it is possible to suppress dust and foreign matter from adhering to the transparent adhesive member 50.

  The protective cover 70 only needs to be disposed so that dust, foreign matter, and the like do not adhere to the transparent adhesive member 50, and the material and type of the protective cover 70 are not particularly limited. For example, a general tape such as polyethylene or polyvinyl chloride is used for the protective cover 70, and preferably a black or gray tape is used. Further, although not shown, the protective cover 70 may also be disposed on the non-light-emitting side of the backlight of the display panel 10.

  The above modification can also be applied to Embodiments 2 and 3 described later.

<Embodiment 2>
FIG. 12 is a cross-sectional view showing the configuration of the liquid crystal display device according to the second embodiment. Hereinafter, in the liquid crystal display device 100 according to the second embodiment, components that are the same as or similar to those in the first embodiment are denoted by the same reference numerals, and different components are mainly described.

  The liquid crystal display device 100 of the second embodiment is different from the liquid crystal display device 100 of the first embodiment in the shape and arrangement of the polarizing plate 20 located on the transparent adhesive member 50 side. Specifically, in the first embodiment, each of the two display panels 10 adjacent to each other in the display area includes the polarizing plate 20 that is not in contact with each other. On the other hand, in the liquid crystal display device 100 according to the second embodiment, the two display panels 10 adjacent to each other in the display area are continuous to each of the adjacent display areas and the area between the adjacent display areas. One polarizing plate 22 is provided. In the second embodiment, in the display area (not shown), components other than the polarizing plates 21 and 22 in the display panel 10 in a plan view (for example, the first substrate or the second substrate of the display panel 10). The same or smaller area is applied.

  Next, a detailed configuration of the liquid crystal display device 100 according to the second embodiment and a manufacturing method thereof will be described with reference to FIGS. 13, FIG. 14, FIG. 16 and FIG. 17 are cross-sectional views showing the manufacturing method. FIG. 15 is a back view of the image display surface of the liquid crystal display device 100 as viewed from the viewpoint 3 of FIG. It is.

  While applying a certain pressure using a rubber roller, as shown in FIG. 13, the transparent adhesive member 50 is affixed to the 1st main surface 30a of the front surface protection board 30 (process 1). The process up to step 1 is the same as the manufacturing method of the liquid crystal display device 100 according to the first embodiment, and thus detailed description thereof is omitted.

  Next, while applying a certain pressure using a rubber roller, one polarizing plate 22 is attached to the transparent adhesive member 50 attached to the first main surface 30a of the front protective plate 30 as shown in FIG. (Step 2). As shown in FIG. 15, after Step 2, one polarizing plate 22 has no seam and is pasted so as to cover the opening end 41 and the opening end 42 of the printing layer 40. That is, the peripheral portion 221 of the polarizing plate 22 is disposed on the printing layer 40, and in the back view, the peripheral portion 501 of the transparent adhesive member 50, and each of the opening end 41 and the opening end 42 of the printing layer 40. Between the two.

  Next, as shown in FIG. 16, components other than the polarizing plate 22 of the display panel 10 are attached to the polarizing plate 22 attached to the transparent adhesive member 50 with an adhesive (not shown) having a thickness of about 25 μm. Combine (step 3). Note that when the pressure-sensitive adhesive formed on the polarizing plate 22 is thin or hard, bubbles may be generated between the polarizing plate 22 and components other than the polarizing plate 22 of the display panel 10. Therefore, pressure-sensitive adhesives with different flexibility and thickness or laminated pressure-sensitive adhesives are applied as appropriate. In the second embodiment, in a low pressure environment of about 100 Pascal, the portions other than the polarizing plate 22 of the two display panels 10 and the polarizing plate 22 attached to the transparent adhesive member 50 are aligned. However, they were bonded together at a pressure of about 1 megapascal.

  Thereafter, as shown in FIG. 17, the transparent adhesive member 50 is fully cured by irradiating from the second main surface 30 b side of the front protective plate 30 with ultraviolet light 60 having an integrated light quantity of 3 Joules / square centimeter. Then, after the main curing, the side surface of the transparent adhesive member 50 is irradiated with ultraviolet light having an integrated light quantity of 3 Joules / square centimeter as described above, and is not cured by being blocked by the printing layer 40 during the main curing. The part is also cured (step 4). In addition, ultraviolet irradiation is not implemented when the adhesive sheet which is not semi-curable is used for the transparent adhesive member 50, or when a thermosetting adhesive sheet or a transparent adhesive resin is used. Further, the irradiation of the ultraviolet light to the side surface of the transparent adhesive member 50 is carried out when a transparent adhesive of a type that cures even if the printing layer 40 is present at the time of main curing is used for the transparent adhesive member 50. It does not have to be. In addition, the order of the irradiation of the ultraviolet light for the main curing and the irradiation of the ultraviolet light to the side surface of the transparent adhesive member 50 may be switched. Thus, the liquid crystal display device 100 shown in FIG. 12 is completed.

  The display state of the liquid crystal display device 100 according to the second embodiment thus manufactured was compared with the display state of the related liquid crystal display device 200 shown in FIG.

  As shown in FIG. 18, in the liquid crystal display device 100 according to the second embodiment, one transparent adhesive member 50 and one polarizing plate 22 are bonded to the front protective plate 30 without a joint (a gap). It is possible to further suppress the bright line from being visually recognized by the observer, and to obtain a generally good display quality.

  Also in the liquid crystal display device 100 according to the second embodiment, as shown in FIG. 19, stray light 80 that has passed through the transparent adhesive member 50 and the polarizing plate 22 is generated at the end face of the first substrate or the second substrate of the display panel 10. As a result of being reflected or scattered by the light and reaching the observer as the light 90, the bright line may be visually recognized by the observer. However, in the liquid crystal display device 100 according to the second embodiment, the intensity of the stray light 80 that has passed through the transparent adhesive member 50 and the polarizing plate 22 indicated by the solid line arrows in FIGS. As a result, the emission line is reduced to about 25 to 50%, so that the bright line can be made less visible than the related liquid crystal display device 200, and a good display quality can be obtained.

<Embodiment 3>
FIG. 20 is a cross-sectional view showing the configuration of the liquid crystal display device according to the third embodiment. Hereinafter, in the liquid crystal display device 100 according to the third embodiment, the same or similar components as those of the first embodiment are denoted by the same reference numerals, and different components will be mainly described.

  The liquid crystal display device 100 according to the third embodiment is different from the liquid crystal display device 100 according to the first embodiment in the shape and arrangement of the polarizing plate 20 located on the transparent adhesive member 50 side. Specifically, in the first embodiment, each of the two display panels 10 adjacent to each other in the display area includes the polarizing plate 20 that is separated in the area between the adjacent display areas. On the other hand, in the liquid crystal display device 100 according to the third embodiment, the two display panels 10 adjacent to each other in the display area include a relatively large polarizing plate 23 in the vicinity of the bent portion 31 of the front protective plate 30. . As a result, each of the two display panels 10 adjacent to each other in the display area includes the polarizing plates 23 that are in contact with each other in an area between the adjacent display areas (an area near the bent portion 31).

  That is, the polarizing plate 23 is formed so as to cover the transparent adhesive member 50 in the vicinity of the bent portion 31 of the front protective plate 30 (the vicinity where the display panel 10 is in contact). In the third embodiment, in the display area (not shown), components other than the polarizing plates 21 and 23 in the display panel 10 in plan view (for example, the first substrate or the second substrate of the display panel 10). The same or smaller area is applied.

  According to such a configuration, the liquid crystal display device can be easily manufactured by using almost the same manufacturing process as the conventional one, and the display quality improvement effect shown in the second embodiment can be obtained. In the third embodiment, the number of display panels 10 is two, but may be three or more, and it is sufficient that at least two of the plurality of polarizing plates 23 of the plurality of display panels 10 are in contact with each other.

  Since the manufacturing method of the liquid crystal display device 100 according to the third embodiment is the same as that of the liquid crystal display device 100 according to the first embodiment, detailed description thereof is omitted. The two display panels 10 according to the third embodiment include components other than the polarizing plate 23 of each display panel 10 (for example, the first display panel 10) at a portion corresponding to the bent portion 31 of the front protective plate 30 with which the display panel 10 is in contact. A polarizing plate 23 having a size larger than that of the component is attached so as to protrude from the outline of the first substrate or the second substrate.

  The amount of the polarizing plate 23 that protrudes from the outer periphery of the display panel 10 is adjusted so that the display panel 10 comes into contact with each other in the vicinity of the bent portion 31 when the two display panels 10 are attached to the front protective plate 30. FIG. 21 is a back view of the image display surface of the liquid crystal display device 100 according to the third embodiment viewed from the viewpoint 4 of FIG. 20 in the direction of the arrow after the step corresponding to the step 2 of the second embodiment. As shown in FIG. 21, each of the peripheral edge portions 231 of the two polarizing plates 23 is disposed on the printing layer 40, and when viewed from the back, the peripheral edge portion 501 of the transparent adhesive member 50 and the opening end portion of the printing layer 40. 41 and the open end 42. Further, the peripheral edge portions 231 of the two polarizing plates 23 are disposed in the vicinity of the bent portion 31 of the front protective plate 30 and in contact with each other between the opening end portion 41 and the opening end portion 42 of the printing layer 40. ing.

  The display state of the liquid crystal display device 100 according to the second embodiment thus manufactured was compared with the display state of the related liquid crystal display device 200 shown in FIG.

  As shown in FIG. 22, in the liquid crystal display device 100 according to the third embodiment, one transparent adhesive member 50 and two polarizing plates 23 that are in contact with each other in the vicinity of the bent portion 31 are connected to the front protective plate 30. Since it is pasted without any gap, it is possible to further suppress the bright line from being visually recognized by the observer, and to obtain a generally good display quality.

  Also in the liquid crystal display device 100 according to the third embodiment, as shown in FIG. 23, stray light 80 that has passed through the transparent adhesive member 50 and the polarizing plate 23 is generated at the end face of the first substrate or the second substrate of the display panel 10. As a result of being reflected or scattered by the light and reaching the observer as the light 90, the bright line may be visually recognized by the observer. However, in the liquid crystal display device 100 according to the third embodiment, the light intensity of the stray light 80 that has passed through the transparent adhesive member 50 and the polarizing plate 23 indicated by solid line arrows in FIGS. As a result, the emission line is reduced to about 25 to 50%, so that the bright line can be made less visible than the related liquid crystal display device 200, and a good display quality can be obtained.

  It should be noted that the present invention can be freely combined with each embodiment and each modification within the scope of the invention, and each embodiment and each modification can be appropriately modified and omitted.

  DESCRIPTION OF SYMBOLS 10 Display panel, 10a Display surface, 20, 22, 23 Polarizing plate, 30 Front protective plate, 30a 1st main surface, 30a1, 30a2 surface, 30b 2nd main surface, 31 Bending part, 50 Transparent adhesive member, 70 Protective cover , 100 Liquid crystal display device.

Claims (6)

A plurality of display panels each having a flat display surface;
A second main surface opposite to the first main surface, including a first main surface including a bent surface composed of a plurality of planar surfaces, and a curved surface provided corresponding to a bent portion of the bent surface. And a front protective plate having,
The display surfaces of the plurality of display panels and the plurality of surfaces of the first main surface are bonded to each other in a state where display regions for displaying images among the display surfaces of the display panels are adjacent to each other. A transparent adhesive member,
The front protective plate is made of a single material,
The liquid crystal display device, wherein the transparent adhesive member is continuously disposed in each of the adjacent display areas and an area between the adjacent display areas. The liquid crystal display device according to claim 1,
The display panel adjacent to the display area is:
A liquid crystal display device comprising: a polarizing plate located on the transparent adhesive member side and continuously disposed in each of the adjacent display regions and a region between the adjacent display regions. The liquid crystal display device according to claim 1,
Each of the display panels adjacent to the display area is
A liquid crystal display device comprising: a polarizing plate located on the transparent adhesive member side that is in contact with each other in a region between adjacent display regions. The liquid crystal display device according to claim 1, wherein the liquid crystal display device is a liquid crystal display device.
The liquid crystal display device, wherein an area of the first main surface is larger than an area where the display surfaces of the plurality of display panels are combined. The liquid crystal display device according to any one of claims 1 to 4,
A liquid crystal display device further comprising a protective cover that covers a portion of the transparent adhesive member that is exposed from an outer periphery of the display panel and that is in contact with the bent portion. The liquid crystal display device according to any one of claims 1 to 5,
The liquid crystal display device, wherein a refractive index of the front protective plate and a refractive index of the transparent adhesive member are substantially the same.

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