WO2008004358A1

WO2008004358A1 - Optical component, display panel, display device and method for putting identification mark on optical component

Info

Publication number: WO2008004358A1
Application number: PCT/JP2007/055024
Authority: WO
Inventors: Kouji Kusuda
Original assignee: Sharp Kabushiki Kaisha
Priority date: 2006-07-04
Filing date: 2007-03-14
Publication date: 2008-01-10

Abstract

A subject method is possible to simply identify optical components of which visual inspection cannot judge kinds. A mark (A, A') indicative of a type of a liquid crystal display device for which the polarizer sheet is used, a mark (B, B') indicative of a manufacturer of the polarizer sheet, a mark (C) indicating that the polarizer sheet is affixed to the video display surface (front surface), and the like are put on a side surface of the polarizer sheet (10a, 10b, 10c) disposed on a panel of the liquid crystal display panel, so that kinds of the polarizer sheets can be identified even after a protective film and a separator are removed.

Description

Specification

OPTICAL MEMBER, DISPLAY PANEL, DISPLAY DEVICE, AND METHOD FOR PROVIDING IDENTIFICATION DISPLAY ON OPTICAL MEMBER

[0001] The present invention relates to an optical member such as a polarizing sheet or a diffusion sheet used in a display device such as a liquid crystal display device.

Background art

An example of a flat display device is a liquid crystal display device such as a liquid crystal TV provided with a liquid crystal display panel. In this liquid crystal display device, various sheet-like or plate-like optical members such as a polarizing sheet, a diffusion sheet, and a lens sheet are used. FIG. 7 shows an exploded perspective view of a general liquid crystal display device.

As shown in the figure, a polarizing sheet 94a, which is a kind of the optical member described above, is provided on the front and back surfaces of a liquid crystal display panel 92 disposed between an outer frame 91 and an inner frame 93 of a liquid crystal display device 90. , 94b is attached. Further, between the liquid crystal display panel 92 and the light source 96 that irradiates it from the back side, a diffusion sheet as an optical member and an optical sheet 98 such as a lens sheet are overlapped and arranged.

By the way, such an optical member is selected according to the function, grade, and the like of the liquid crystal display device to be manufactured, and various kinds of optical members are used in combination in accordance with desired characteristics. However, the optical materials are almost the same regardless of the type of material, and if the screen size of the liquid crystal display device is the same, the size is almost the same, so the appearance is completely indistinguishable. Many Therefore, in an assembly line of a liquid crystal display device on which various types of optical members are placed, there is a problem that an operator mistakenly uses an optical member for another liquid crystal display device.

[0005] Therefore, in order to easily identify the types and various uses of these optical members by visual observation, conventionally, the optical members are generally cut into a corner of the optical member within a range that does not affect the image display unit of the liquid crystal display device. And was identified by the presence or absence of the cut. However, along with the variety of liquid crystal display devices manufactured by Kashiba-zu, the types of optical members used in the liquid crystal display device assembly line are also increasing. Cutting corners However, there is a problem that a wide variety of optical members cannot be sufficiently identified only by the above-described method.

For such problems, for example, Japanese Patent Application Laid-Open No. 2000-321422 discloses a protective film for a separator that protects the surface of an optical member and an adhesive layer and is peeled off when incorporated in a liquid crystal display device. By applying ink as information to identify the optical member on the surface, it was possible to visually identify them even in the assembly line of liquid crystal display devices with a wide variety of optical members. The technology is disclosed.

Disclosure of the invention

Problems to be solved by the invention

[0007] In the method of applying such ink to the surface of the protective film or the like of the optical member while pressing, the protective film or the like is peeled off and the optical member is incorporated into the product. The type cannot be identified. In other words, when an irregular optical member is attached, it is very difficult to visually determine this. Further, in the method disclosed in Japanese Patent Laid-Open No. 2000-321422, since ink is applied to the surface of the sheet-like optical member, it is necessary to apply the optical member one by one, which is inefficient.

[0008] Therefore, the problem to be solved by the present invention is to make it possible to always recognize the type of optical member such as a polarizing sheet and a diffusion sheet used in a display device or a display panel. The purpose is to improve the accuracy of work and the reliability of quality when assembling to equipment and display panels.

Means for solving the problem

[0009] In order to solve the above problems, an optical member according to the present invention is a sheet-like or plate-like optical member, and an identification display relating to type information is locally or entirely attached to a side surface of the optical member. It is a summary.

In this case, the identification display may be provided at a position shifted from the central axis of the surface of the optical member. The identification display may be made by applying a paint or ink to the side surface of the optical member. The paint or ink may be a fluorescent paint or fluorescent ink. Further, the identification display may be provided by deformation or modification of a side surface of the optical member.

[0011] Then, a display panel or a display device including such an optical member is configured. And good. In addition, it is good to configure as a display device provided with a plurality of such optical members, and the position of the identification display of each of these optical members is substantially near.

[0012] Further, as a method for giving an identification display to such an optical member, a plurality of the same type of sheet-like or plate-like optical members are stacked in a laminated state, and the optical member is placed on the side surface thereof. It is preferable that the group type information is added.

The invention's effect

[0013] According to the optical member of the present invention, by attaching an identification display to the side surface of the optical member, it is possible to visually identify a large number of types of optical members by changing the color and size, for example. it can. Further, even after the protective film of the optical member is peeled off and assembled to a predetermined place, the optical member still has an identification display, so that the type of the optical member can be easily determined. In addition, since the identification display is attached to the side surface of the optical member, there is no adverse effect on the video display displayed on the display panel, and it can be used without being influenced by the size of the frame of the display device.

[0014] In this case, if the identification display is attached at a position shifted from the center axis of the surface of the optical member, it is impossible to visually determine the top and bottom or the front and back. Even so, the position of the identification display can be used as a guide, and the top, bottom, left, and back of the optical member can be distinguished. Further, if the identification display is given by application of paint or ink, it is possible to easily give the identification display to the optical member. In addition, if the paint or ink is fluorescent paint or fluorescent ink, the type of optical member can be easily identified even when inspection after assembly is performed in a dark room, and the cause of defects in the inspection process can be identified. It leads to quick 匕. Furthermore, if the identification display is provided by deformation or modification of the side surface of the optical member, there is no problem that the identification display disappears for some reason, as in the case where the identification display is applied with paint.

[0015] Further, according to the display panel or display device provided with such an optical member, it is possible to prevent the optical member from being erroneously attached in the assembly process of the display panel or the display device, and also visually in the inspection process. It is easy to find defective sticking etc., leading to improved product quality by reducing the defective rate. Furthermore, if the positions of the identification indications of the optical members are substantially close to each other, each optical member is normally used in the display device assembly process. When the members are stacked, the identification indications are arranged in a line almost vertically, so that the operator can assemble the identification indication positions of other optical members as a guideline, and easily find mistakes. .

[0016] Then, as a method of giving an identification display to such an optical member, if an identification display is attached to the side surface in a state where a plurality of optical members of the same type are stacked in a stacked manner, at one time Since identification information can be given to a plurality of optical members, there is an advantage that work in the field is efficiently performed.

Brief Description of Drawings

FIG. 1 is a perspective view showing three types of polarizing sheets according to an embodiment of the present invention.

FIG. 2 is a diagram schematically showing a cross section of a general polarizing sheet used in a liquid crystal display device.

FIG. 3 shows a state of sticking of the polarizing sheet according to one embodiment of the present invention, wherein (a) shows a case where the sticking direction of the polarizing sheet according to one embodiment of the present invention is correct, and (b) shows a sticking direction of the polarizing sheet. It shows the case where it is pasted upside down. (c) shows the case where the identification display is attached on the central axis of the surface of the polarizing sheet.

FIG. 4 is a perspective view showing a method for producing a polarizing sheet according to an embodiment of the present invention.

FIG. 5 is an exploded perspective view showing a schematic configuration of a liquid crystal display device including an optical member according to the present invention.

FIG. 6 is a perspective view showing a method for giving an identification display by thermally deforming a polarizing sheet according to an embodiment of the present invention.

FIG. 7 is an exploded perspective view showing a schematic configuration of a liquid crystal display device generally used conventionally.

BEST MODE FOR CARRYING OUT THE INVENTION

[0018] (Example 1)

Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. As shown in FIG. 7, the polarizing sheets 94a and 94b, which are examples of the optical member according to the embodiment of the present invention, are used for the liquid crystal display panel 92 in which liquid crystal is filled between a pair of glass substrates. Used by being affixed to the front and back surfaces and irradiated from the light source 96 through the optical sheet 98. It has the function of extracting only the light that vibrates in a certain direction from the light that vibrates in the direction.

[0019] FIG. 1 shows, as an example, three types of polarizing sheets having identification indications on side surfaces according to an embodiment of the present invention. As shown in the figure, the polarizing sheets 10a to 10c according to the present invention are marked with identification marks with fluorescent paints at a plurality of positions on the side surfaces, and the fluorescent paints are used for the types and applications of the polarizing sheets. The colors are different accordingly.

Here, the polarizing sheet 10a shown in FIG. 1 (a) is marked with a mark A indicating the model name of the liquid crystal display device in which the polarizing sheet 10a is used and a mark B indicating the manufacturer of the polarizing sheet. ing. Similarly, the polarizing sheet 10b shown in FIG. 1 (b) is provided with a mark A indicating the model name of the liquid crystal display device used and a mark indicating the name of the polarizing sheet manufacturer. The polarizing sheet 10c shown in FIG. 1 (c) is marked with a mark indicating the model name of the liquid crystal display device used and a mark indicating the manufacturer name of the polarizing sheet.

That is, the polarizing sheets 10a and 10b shown in FIGS. 1 (a) and 1 (b) are given the same mark A as the model name identification display of the liquid crystal display device used. Although it is used for display devices, it is used for the same liquid crystal display device because the identification mark of the manufacturer of the polarizing sheet manufacturer is marked with a different mark. It turns out that it is a made polarizing sheet.

[0022] Further, since the polarizing sheet 10c shown in FIG. 1 (c) is marked with a mark A 'different from the polarizing sheets 10a and 10b and the same mark as the polarizing sheet 10b, the polarizing sheet 10a , 1 Ob shows that the liquid crystal display device used is different, but it is a polarizing sheet made by the same manufacturer as the polarizing sheet 10b.

[0023] Further, although not attached to the polarizing sheet 10a, the mark C attached to the polarizing sheets 10b and 10c indicates that the polarizing sheet is attached to the front side (image display surface) of the liquid crystal display panel. Show. In other words, the liquid crystal display panel of the liquid crystal display device in which the polarizing sheets 10a and 10b are used has a mark C attached! The polarizing sheet 10a has a mark C attached to the back side of the liquid crystal display panel. This indicates that the polarizing sheets 10b and 10c are attached to the front side of the liquid crystal display panel, and prevents the wrong attachment of the polarizing sheet in the liquid crystal display panel assembly process. In this way, by attaching a mark as an identification display to the side surface of the polarizing sheet, the type of the polarizing sheet can be identified. As shown in this embodiment, when the manufacturing sheet name information is given to the polarizing sheet, if a defective polarizing sheet is found, it is immediately divided into which manufacturer's polarizing sheet. It is effective for investigations. In addition, if information on the model name of the liquid crystal display device to be used is given, it is possible to produce many types of products in small quantities, so even if many models are made on the same assembly line, it is difficult to make a mistake in attaching the polarizing sheet. .

Here, FIG. 2 showing a schematic diagram of a cross section of a general polarizing sheet will be described. As shown in the drawing, the polarizing sheet 10 has a configuration in which a polarizing film 22 that polarizes light from a light source such as a knocklight is sandwiched between a pair of substrate films 24a and 24b. An adhesive 26 for attaching the polarizing sheet 10 to the liquid crystal display panel is applied to the lower surface of the substrate film 24b, and the adhesive 26 is protected by a separator 28. The upper surface of the substrate film 24a is protected by a protective film 29. These separator 28 and protective film 29 are affixed as protective sheets and are peeled off during the product assembly process.

[0026] Thus, the separator 28 and the protective film 29 that are peeled off are attached to both surfaces of a general polarizing sheet. Therefore, even if an identification display is attached to the surface of the polarizing sheet before assembly, if the separator 28 or the protective film 29 is peeled off during the assembly process, the identification display is also removed together with the separator 28 or the protective film 29. This makes it impossible to determine the type of polarizing sheet.

[0027] Since the polarizing sheet according to the present embodiment is provided with a mark as an identification display on the side surface, the identification display is also provided on a portion excluding the separator 28 and the protective film 29 that are peeled off. Therefore, even after the separator 28 and the protective film 29 are peeled off, the identification display remains on the polarizing sheet. For example, when a defect is detected in the lighting inspection of the liquid crystal display panel after the polarizing sheet is attached, the attached polarizing sheet is properly You can also check the identification when you confirm that it is. In addition, since the identification display is attached with fluorescent paint, even if this inspection process is performed in a dark room, the color of the mark and the presence or absence of the mark will not be mistaken or overlooked. In other words, defects occur during the inspection process. In such a case, it is difficult to judge visually, and there is an advantage that it is not necessary to judge the display quality of the liquid crystal display panel with a special device.

[0028] In the above-described embodiment, the method for identifying the manufacturer name, the model used, and the like of the polarizing sheet with the color of the fluorescent paint has been described. However, the identification method by providing the identification display is not limited to this. Absent. For example, the size, position, number, etc. of the marks may be changed according to the type of the polarizing sheet, or these may be combined. The information given to the polarizing sheet is not limited to the manufacturer name and the model used. For example, in addition to the identification display for each type of liquid crystal display device, an identification display may be given for each type of liquid crystal display panel. It is also possible to provide an identification display indicating the characteristics of each polarizing sheet. For identification display, fluorescent ink, ordinary paint (dye, pigment) or ink may be used instead of fluorescent paint.

[0029] It is preferable that the above-described identification display is uniformly attached to a position shifted from the central axial force on the surface of the polarizing sheet in consideration of the attaching direction of the polarizing sheet. For example, as shown in Fig. 3 (a), when the polarizing sheet 10b is attached to the liquid crystal display panel 32 in a specific direction and the polarizing sheet 10b is attached in the normal direction, the mark is displayed. Unify the places where the identification mark is attached so that the position is a specific position (A in the figure). With such a configuration, when the polarizing sheet 10b is attached upside down, the mark is not located at the position A as shown in FIG. 3 (b).

[0030] That is, by using such a polarizing sheet, the mark position for identification display can be used as a guide, and it is possible to prevent the polarizing sheet from being affixed to the liquid crystal display panel in the reverse direction or upside down. it can. In addition, when a polarizing sheet sticking apparatus is used and a polarizing sheet is automatically stuck, the mark position can be used as a guide to set the polarizing sheet. Also, even if a sticking error as shown in Fig. 3 (b) occurs, the difference from the non-defective product is clear, so it is easy to find a defective product simply by confirming the mark position in the inspection process. it can.

Furthermore, as shown in FIG. 3 (a), when the polarizing sheets 10b and 10a are attached in the correct direction on both surfaces of the liquid crystal display panel 32, the identification indications of the polarizing sheets 10b and 10a are in the same direction. If it is placed in this position, it is possible to further reduce the defect rate due to a mistake in attaching the polarizing sheet.

[0032] That is, after the polarizing sheets are attached to both sides of the liquid crystal display panel, When the positions of the liquid crystal display panels are different on the front and back surfaces, it can be instantaneously determined that at least one of the polarizing sheets is stuck in the wrong direction.

[0033] It should be noted that this method cannot be used when the mark position of the identification display is symmetric with respect to the central axis of the surface of the polarizing sheet. For example, as shown in FIG. 3 (c), when the mark M is attached on the central axis X of the polarizing sheet 30, even when the polarizing sheet 30 is attached to the liquid crystal display panel 32 with the front and back reversed. Since the position of the mark M does not change from the case where it is correctly pasted, it cannot be judged from the mark position whether it is pasted in the correct direction.

Next, FIG. 4 shows a schematic diagram of a method for producing a polarizing sheet according to the present embodiment. As described above, the polarizing sheet according to the present embodiment has a configuration in which an identification display is attached to the side surface thereof, so that the state of the polarizing sheet laminate 40 in which the same kind of polarizing sheets 41 are laminated as shown in the drawing. Therefore, it can be created by applying paint or ink to the side surface at a time. When applying, a brush 42 soaked with paint as shown in the figure may be used. In addition, transfer using a plate soaked with ink or printing using an ink jet method is also acceptable. When using a plate, it is possible to attach the identification display all at once by using a plate with a pattern of identification display.

[0035] As described above, when marking on the protective film on the surface of the polarizing sheet as in the prior art, it is necessary to mark each polarizing sheet one by one. An identification display can be easily attached to the side surface of the polarizing sheet.

In the above-described embodiment, the polarizing sheet is used as a specific example of the optical member according to the present invention. However, it goes without saying that the configuration of the present invention can be applied to various optical members. Yes. For example, in order to increase the brightness when the liquid crystal display panel is viewed from the front by condensing the light emitted from a diffusion plate, diffusion sheet, diffusion sheet, etc. that diffuses light with a light source power and makes the luminance distribution uniform. The configuration of the present invention can also be applied to a lens sheet, a brightness increasing sheet for increasing the overall brightness including the brightness when the liquid crystal display panel is viewed from an oblique side, and the like.

[0037] Next, a liquid crystal display device having a liquid crystal display panel using such an optical member !, I will explain. As shown in FIG. 5, the liquid crystal display device 50 mainly includes a liquid crystal display panel section 60 and a backlight unit 70 that irradiates the liquid crystal display panel section 60 from the back side.

[0038] The liquid crystal display panel 60 is attached with the polarizing sheets 64a and 64b according to the present invention having identification indications on the side surfaces on both sides of a liquid crystal display panel 62 filled with liquid crystal between a pair of glass substrates. It is arranged above the knock light unit 70 in a state of being sandwiched between a frame-shaped outer frame 52 and an inner frame 54.

[0039] The knocklight unit 70 includes a box-shaped metal base tray 56 having an open top surface, a plurality of tubular lamps 82 arranged in parallel in the base tray 56, and the tubular lamps 82. It is composed of a diffusion plate 72 laid to make the luminance distribution of the tubular lamp 82 uniform, and optical sheets 74, 76, 78 such as a diffusion sheet and a lens sheet disposed on the diffusion plate 72. ing.

The diffusion plate 72 is formed in a substantially rectangular shape that is substantially the same as the optical sheets 74, 76, 78.

The diffusing plate 72 has a slightly thick transparent plate shape and is less prone to stagnation when placed, and the optical sheets 74, 76, and 78 placed thereon are almost flat. It can be supported flat.

[0041] The base tray 56 has an interior 80 for accommodating a plurality of tubular lamps 82, 82.

A peripheral edge 84 serving as a mounting allowance for mounting the diffusion plate 72 and the optical sheets 74, 76, 78 is formed with a predetermined thickness on the peripheral edge of the interior 80. On the peripheral edge 84 of the base tray 56, an upright part 86 is erected along the outer periphery to form a place on which the diffusion plate 72 and the optical sheets 74, 76, 78 are placed.

[0042] The ends of the plurality of tubular lamps 82, 82... Arranged in the base tray 56 are the longitudinal ends of the interior 80 of the base tray 56, and are supported by the lamp holders 88 and 88. ing.

[0043] On the side surfaces of the optical members of the polarizing sheets 64a and 64b, the diffusing plate 72, and the optical sheets 74, 76, and 78, marks as identification indications are attached. In the present embodiment, like the polarizing sheet of FIG. 1 described above, the mark located at A in the figure indicates the model name of the liquid crystal display device used, and therefore the same mark is attached to all sheets. Has been. The mark located at B in the figure is an identification display that indicates the name of the manufacturer of each optical member. [0044] In addition, at the position C in the figure, the presence / absence of the marks on the polarizing sheets 64a and 64b is an identification display indicating whether the polarizing sheets 64a and 64b are attached to the front surface or the back surface of the liquid crystal display panel 62. The marks at the position C in the drawings of the optical sheets 74, 76, and 78 have different sizes. In other words, when correctly assembled into the liquid crystal display device as shown in the figure, they are arranged in the order of the ones with the largest mark C from the liquid crystal display panel 62 side, which is a guideline for the installation of the knock light unit 70! .

[0045] (Example 2)

In the first embodiment described above, the identification display is given by applying paint or ink. However, the identification unit or the identification unit is modified so that the property is visually different between the identification unit and the identification unit. An indication can be formed. Examples of the denaturation treatment include methods using heat, chemicals, high energy lasers, and the like.

[0046] A method for providing an identification display by heat treatment will be described with reference to FIG. Since an optical sheet is often composed of a resin, a method by heat treatment in which the heat distortion temperature is relatively low is simple.

[0047] By bringing the iron sheet 100 having an electric heating mechanism connected to the power source 104 via the power cord 102 on the side surface of the polarizing sheet laminate 40 in which the polarizing sheets 41 are laminated as shown in the figure, The side surface of the polarizing sheet laminate 40 is locally modified. At this time, it is desirable that the temperature of the iron 100 is equal to or higher than the heat deformation temperature of the polarizing sheet 41. When the side surface of the polarizing sheet laminate 40 brought into contact with the trowel 100 is thermally denatured, the shape or roughness of the side surface of each polarizing sheet 41 is changed, so that it can be visually identified. In this case, the contact time of the iron 100 is adjusted so that the heat denaturation does not reach the display area inside the polarizing sheet 41.

[0048] Alternatively, the tip of the iron 100 may be formed in a concave-convex shape, and the side surface of the polarizing sheet 41 may be deformed in a concave-convex shape to give an identification display. In this case, it is easy to change the identification display for each type of the polarizing sheet 41 if a plurality of tips 100 having different irregularities are prepared in advance.

[0049] According to the optical member according to the present invention described above, identification of the model name to be used and an identification display that serves as a guide for the mounting position are attached. Type and installation position can be confirmed. Therefore, it is possible to reduce the mounting error of the optical member in the assembly process, improve the production efficiency of the liquid crystal display device, and improve the quality. Although the embodiments of the present invention have been described in detail above, the present invention is not limited to the above embodiments, and various modifications can be made without departing from the scope of the present invention. For example, in the above embodiment, the optical member used in the liquid crystal display device, and the liquid crystal display device using the optical member are used in the display device such as the force-elect's luminescence display or the plasma display. Needless to say, the present invention can also be applied to a sheet-like or plate-like optical member. Further, the technical idea of the present invention can be applied to optical members other than those used in display devices, display panels, and the like.

Claims

The scope of the claims

[1] An optical member, which is a sheet-like or plate-like optical member, and an identification display relating to type information is given locally or entirely on a side surface of the optical member.

[2] The optical member according to [1], wherein the identification display is provided at a position shifted from a central axis of the surface of the optical member.

[3] The optical member according to [1] or [2], wherein the identification display is performed by applying paint or ink to a side surface of the optical member.

4. The optical member according to claim 3, wherein the paint or ink is a fluorescent paint or fluorescent ink.

[5] The optical member according to [1] or [2], wherein the identification display is given by deformation or modification of a side surface of the optical member.

[6] A display panel comprising the optical member according to any one of claims 1 to 5.

[7] A display device comprising the display panel according to [6].

[8] A display device comprising a plurality of the optical members according to any one of claims 1 to 5, wherein each of the optical members has an identification display position in the vicinity.

[9] With the same type of sheet-like or plate-like optical members stacked in a stack

An identification display imparting method for an optical member, characterized in that an identification display relating to the type information of the optical member group is attached to the side surface.