JP6124265B2 - Optical sheet laminating method, optical sheet laminating apparatus, and program used for the apparatus - Google Patents

Description

  The present invention relates to an optical sheet laminating method for laminating an optical sheet to a display panel, an optical sheet laminating apparatus, a display apparatus, and the like.

  In response to the recent demand for higher functionality of display devices, stereoscopic image display and viewing angle can be achieved by combining optical panels such as lenticular lens sheets, prism sheets, and diffusion sheets with display panels that use electro-optical elements such as liquid crystals. Unique display devices that enable control and the like have come to be used.

  As an example of such a display device, a display device using a lenticular lens sheet will be described. FIG. 21A is a perspective view showing a lenticular lens sheet, and FIG. 21B is a schematic view showing a stereoscopic display method using the lenticular lens sheet.

  As shown in FIG. 21A, a lenticular lens sheet 110 has a flat surface on one surface and a cylindrical surface having a cylindrical surface and a hook-shaped (generally segmented) cross section on the other surface. 111 are continuously extended in the parallel direction.

  As shown in FIG. 21B, on the display panel 114, the left-eye pixels 115a and the right-eye pixels 115b are alternately arranged so as to correspond to the focal points of the respective cylindrical lenses 111. When the left eye pixel 115a and the right eye pixel 115b are driven in accordance with a predetermined signal by a drive circuit (not shown), the cylindrical lens 111 forms a left eye image in the left eye region 120a and a right eye image in the right eye region 120b. This makes it possible for the observer to recognize the stereoscopic image. Of course, the normal two-dimensional image can be displayed by driving the right-eye pixel 115a and the left-eye pixel 115b with the same signal.

  Further, as a display device using a lenticular lens sheet, there is a simultaneous multiple image display device that displays a plurality of images simultaneously. This is also the same method as the above-described stereoscopic display, and different images can be simultaneously displayed to a plurality of observers by distributing images with respect to the observation direction by the cylindrical lens.

  In a display device using such a microlens array or lenticular lens sheet, a lenticular lens sheet or the like is mounted on the display panel with high accuracy in order to obtain high-quality stereoscopic image display or multiple image simultaneous display. Is required. In particular, a high-definition display device mounted on a terminal device or the like in recent years requires unprecedented bonding with high accuracy, and bonding accuracy on the order of μm is required.

  In order to attach optical sheets such as lenticular lens sheets to the display panel with high accuracy, alignment marks are provided on the optical sheet and the display panel, and these marks are read and aligned to perform bonding. There is a need. This technology is hereinafter referred to as “Related Technology 1”.

  In Related Art 1, in order to make the bonding accuracy on the order of μm, it is necessary to form the marks on the optical sheet and the marks on the display panel on the order of μm. For example, the mark on the lenticular lens sheet is required to be accurate with a distance from the apex of the cylindrical lens on the order of μm. However, it is generally difficult to form a mark with an accuracy of μm when manufacturing an optical sheet by machining.

  On the other hand, Patent Document 1 discloses another lens mark reading method. Hereinafter, this technology is referred to as “Related Technology 2”. In Related Art 2, a special lens mark is not formed on the lenticular lens sheet, but the lenticular lens sheet is irradiated with light, and the position information of the cylindrical lens is read from the luminance distribution of transmitted light generated according to the lens imaging performance and displayed. The panel mark is imaged and aligned with the panel through a cylindrical lens.

  Patent Document 2 discloses a process of bonding an optical element array sheet to a display panel using a curved optical element holding head.

JP 2009-223193 A (refer to FIG. 3 and FIG. 8) JP 2009-222903 A (see FIG. 39)

  However, Related Technique 1 has the following problems. The optical sheet mark is disposed on the optical sheet surface, and the panel mark is disposed on the display panel surface. At this time, for example, when both marks are superimposed on each other and imaged with a camera and each mark is read from the image, it is difficult to focus on both marks simultaneously because the distance from the camera to both marks is different. Therefore, the reading of the mark is hindered.

  Taking a liquid crystal display device as an example, as shown in FIG. 22A, the panel mark 132 is formed on the drive substrate 152 or the counter substrate 153, and the optical sheet mark 150 is formed on the optical sheet 151. Therefore, the optical sheet mark 150 and the panel mark 132 need to be separately focused when the same camera is used for imaging because the counter substrate 153, the polarizing plate 154, and the optical sheet 151 exist between them. That is, both mark reading accuracy depends on the feeding accuracy in the focal direction of the camera. Further, since it takes extra time for focusing, it is disadvantageous in terms of tact.

  Furthermore, since the panel mark 132 is read through the optical sheet 151, the position of the panel mark 132 is observed by being changed by the refracting action of the optical sheet 151, so that correction is necessary. Further, the luminance distribution of transmitted light obtained by irradiating the optical sheet 151 with light largely depends on the imaging performance of the cylindrical lens. However, when the variation in the radius of curvature of each lens is large, or when the optical sheet 151 itself is distorted, the luminance distribution changes non-uniformly in the plane, leading to deterioration in mark reading accuracy.

  In addition, in order to overlap the optical sheet mark 150 and the panel mark 132, the panel mark 132 is disposed immediately below the optical sheet 151. For example, in a liquid crystal display device, as shown in FIG. 22B, the optical sheet 151 is generally smaller in outer shape than the outer shape of the display panel 131 and the outer shape of the polarizing plate 154. Therefore, the fact that the panel mark 132 comes directly below the optical sheet 151 means that the panel mark 132 is arranged in the vicinity of the display area 155 of the display panel 131. In particular, in a normally white liquid crystal display device, the panel mark 132 that causes light leakage (light shielding) is formed near the display region 155, so that the display quality is greatly affected.

  In addition to the problem of Related Technology 1, the present inventors have examined a bonding process between a highly accurate and highly reliable lens and a display panel, and found that there is a new problem. For example, in the case of a lenticular lens sheet that is one of optical sheets, the lens pitch may be non-uniform in the plane as shown in FIG. 23 mainly due to the manufacturing process of the lenticular lens sheet. For example, in FIG. 23A, the lens pitch is non-uniform so that the lens pitch is large at the top, the lens pitch is large at the center in FIG. 23B, and the lens pitch is small at the center in FIG. There are various patterns. Such non-uniformity of the lens pitch has a great influence on the viewing distance that maximizes the stereoscopic viewing area and the size of the stereoscopic viewing area itself in the stereoscopic display device. For this reason, it is necessary to mitigate the influence of lens pitch fluctuations when bonding optical sheets.

  Further, when the optical element forming surface of the optical sheet is held using the sheet holding head, the optical element forming surface has fine irregularities, and therefore the substantial contact area between the optical sheet and the sheet holding head is small. For this reason, there exists a subject that the retention strength with respect to an optical sheet will fall.

  On the other hand, in the related art 1, the position information of the optical sheet mark is read using the presence / absence of light transmitted through the optical sheet, whereas in the related technique 2, the position information of the lens is obtained using the luminance distribution of light transmitted through the optical sheet. read. That is, the related technique 2 has the same problem as the related technique 1 because the position information is obtained using the light transmitted through the optical sheet, as in the related technique 1. Further, the sheet holding head (holding frame for holding the lenticular lens sheet) in Related Art 2 is formed of a light-transmitting material so as not to hinder imaging by the imaging unit (see paragraph 0022 of Patent Document 2). . Therefore, the material of the sheet holding head in the related technique 2 is limited to fragile glass or plastic, and a robust metal or ceramic cannot be used.

  The present invention has been made to solve these problems, and an object of the present invention is to provide an optical sheet that can be mounted with high yield and high accuracy when the optical sheet is mounted on a display panel. A bonding method and a bonding apparatus using the method are provided, and a high-quality display device manufactured using the bonding method is provided.

The method for laminating an optical sheet according to the present invention is as follows.
Bonding of an optical sheet in which an optical sheet having both an optical element surface on which a plurality of optical elements are formed and a non-optical element surface on which the optical element is not formed is bonded to a display panel using a sheet holding head In the method
Contacting one of the optical element surface and the non-optical element surface with the sheet holding head;
Irradiating light from the other of the optical element surface and the non-optical element surface to a contact portion between one of the optical element surface and the non-optical element surface and the sheet holding head,
Read the position information of the contact location from the distribution of the reflected light,
Based on the position information of this contact location, align the position of the optical sheet and the display panel, the optical sheet and the display panel are bonded together,
The optical element is a cylindrical lens composed of a convex lens having a cylindrical surface,
The optical sheet is a lenticular lens film in which a plurality of the cylindrical lenses are arranged at a predetermined pitch,
After reading the position information of the contact location, based on the position information of the contact location, determine the amount of deviation from the design value of the pitch,
When bonding the optical sheet and the display panel, to set the pressure applied to the optical sheet so that the amount of deviation is small,
It is characterized by that.

The optical sheet laminating apparatus according to the present invention is:
In an optical sheet laminating apparatus for laminating an optical sheet having both an optical element surface on which a plurality of optical elements are formed and a non-optical element surface on which the optical element is not formed, to a display panel,
A sheet holding head for holding the optical sheet in contact with one of the optical element surface and the non-optical element surface;
Light is irradiated from the other of the optical element surface and the non-optical element surface to a contact portion between one of the optical element surface and the non-optical element surface and the sheet holding head, and an image of the reflected light distribution is obtained. A first imaging unit to acquire;
A second imaging unit for acquiring an image of a panel mark attached to the display panel;
A moving mechanism for moving at least one of the optical sheet and the display panel in a coordinate space;
The position information of the contact location is read from the image acquired by the first imaging unit and the position information of the panel mark is read from the image acquired by the second imaging unit, and the position information of the contact location and the By controlling the moving mechanism unit based on the position information of the panel mark, the control unit for aligning the position of the optical sheet and the display panel, and bonding the optical sheet and the display panel;
With
The optical element is a cylindrical lens composed of a convex lens having a cylindrical surface,
The optical sheet is a lenticular lens film in which a plurality of the cylindrical lenses are arranged at a predetermined pitch,
The controller, after reading the position information of the contact location, obtains a shift amount from the design value of the pitch based on the position information of the contact location, and when the optical sheet and the display panel are bonded together Setting the pressure applied to the optical sheet so that the amount of deviation is small,
It is characterized by that.

A display device according to the present invention includes:
The display panel on which the optical sheet is pasted by the optical sheet laminating method according to the present invention,
It is characterized by that.

  According to the present invention, by using reflected light instead of transmitted light for reading the position information of the optical sheet, various problems in the case of using the transmitted light can be solved all at once, so that the reading accuracy of the position information of the optical sheet can be improved. Can be improved. Therefore, in the optical sheet laminating step, it is possible to achieve high accuracy and improve yield. Moreover, even if the lens pitch of the optical sheet fluctuates in the stage before bonding, the lens pitch can be made appropriate after bonding by adjusting the bonding pressure.

3 is a schematic diagram illustrating a bonding method according to Embodiment 1. FIG. FIG. 5 is a process diagram illustrating the bonding method according to the first embodiment. It is a schematic diagram which shows the bonding apparatus of Embodiment 1. FIG. 4A is a block diagram illustrating the bonding apparatus according to the first embodiment, and FIG. 4B is a block diagram illustrating an example of a control unit in FIG. 4A. 6 is a graph illustrating an example of an alignment operation in the bonding apparatus according to the first embodiment. FIG. 3 is an image and a side view illustrating a contact portion between a sheet holding head and an optical element surface of an optical sheet in Embodiment 1. 7A is another example of an image showing a contact portion between the sheet holding head and the optical element surface of the optical sheet in Embodiment 1, and FIG. 7B is a non-optical element of the sheet holding head and the optical sheet. It is a side view which shows the state which made the surface contact. FIG. 8A is a schematic diagram illustrating position information of an optical sheet read by a plurality of cameras, and FIG. 8B is a schematic diagram illustrating a sheet holding head when optical sheets are bonded together. FIG. 8C is a schematic diagram illustrating a case where the sheet holding head is provided below the display panel. FIG. 9A is a perspective view, and FIGS. 9B and 9C are schematic diagrams illustrating a position information reading operation. FIG. It is a schematic diagram which shows the bonding process in Embodiment 2, and a process advances in order of FIG. 10 [A] [B] [C]. FIG. 11A is a perspective view illustrating a part of a bonding step in Embodiment 2, and FIG. 11A illustrates a case where a contact portion between the sheet holding head and the optical sheet is parallel to the arc tangent direction of the sheet holding head. FIG. 11B shows a case where the contact point between the sheet holding head and the optical sheet is perpendicular to the arc tangential direction of the sheet holding head. FIG. 10 is a schematic diagram illustrating a case where the sheet holding head in Embodiment 2 is provided on the lower side with respect to the display panel. 6 is a graph illustrating an example of a relationship between a bonding pressure and a lens pitch variation amount before and after bonding in Embodiment 2. FIG. 14A is a plan view showing a lenticular lens in which the lens pitch is nonuniform in the third embodiment, and FIG. 14B is a graph showing the relationship between the bonding pressure and the lens pitch fluctuation amount. FIG. 14C is a graph showing the optimized bonding pressure. FIG. 15A is a plan view showing another example of the lenticular lens in which the lens pitch is nonuniform in the third embodiment, and FIG. 15B is a graph showing the optimized bonding pressure (part 1). FIG. 15C is a graph (No. 2) showing the optimized bonding pressure. 16A is an image and a side view showing a contact portion between the sheet holding head and the optical element surface of the optical sheet in FIG. 16B, and FIG. 16B is an optical sheet in the fourth embodiment (part 1). FIG. 17A is an image and a side view showing a contact portion between the sheet holding head and the optical element surface of the optical sheet in FIG. 17B, and FIG. 17B is an optical sheet in the fourth embodiment (part 2). FIG. FIG. 18A is a plan view showing the optical sheet (No. 3) in the fourth embodiment, and FIG. 18B shows a contact portion between the sheet holding head and the optical element surface of the optical sheet in FIG. It is the image shown. 19A is a perspective view showing a mobile terminal device equipped with a display device in which an optical sheet is bonded to a display panel using the present invention, and FIG. 19B shows a fly-eye lens as an optical sheet. It is a perspective view. It is a top view which shows the display panel and panel mark in this invention. FIG. 21A is a perspective view showing a lenticular lens sheet, and FIG. 21B is a schematic view showing a stereoscopic display method using the lenticular lens sheet. FIG. 22A is a side view showing a liquid crystal display device, and FIG. 22B is a plan view showing the liquid crystal display device. In the lenticular lens sheet, an example in which the lens pitch is non-uniform in the surface is shown, FIG. 23 [A] is an example in which the lens pitch is larger toward the upper side, and FIG. FIG. 23C shows an example in which the lens pitch is smaller toward the center.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments for carrying out the present invention (hereinafter referred to as “embodiments”) will be described with reference to the accompanying drawings. In the present specification and drawings, the same reference numerals are used for substantially the same components.

[Embodiment 1]
In the first embodiment, a case where a lenticular lens sheet composed of a plurality of cylindrical lenses is used as an optical sheet will be described. The optical sheet will be described by taking a lenticular lens sheet as an example in other embodiments as well, but is not limited thereto, and a prism sheet, a reflective sheet, a diffusion sheet, or the like on which a predetermined pattern is formed. An optical element array may also be used.

  FIG. 1 is a schematic diagram illustrating a bonding method according to the first embodiment, and FIG. 2 is a process diagram illustrating the bonding method according to the first embodiment. Hereinafter, a description will be given based on FIG. 1 and FIG.

  The optical sheet laminating method according to the first embodiment is a method in which the optical sheet 10 is bonded to the display panel 30 using the sheet holding head 20. The optical sheet 10 is a lenticular lens sheet composed of a plurality of cylindrical lenses 11 as a plurality of optical elements, and includes an optical element surface 12 on which the cylindrical lens 11 is formed and a non-optical element surface on which the cylindrical lens 11 is not formed. 13. That is, the optical element surface 12 is an uneven surface, and the non-optical element surface 13 is a flat surface. And the bonding method of this Embodiment 1 includes the following process.

  Steps 101 to 103 (FIGS. 1A and 1B): The optical element surface 12 is brought into contact with the sheet holding head 20 (Step 101), and the contact portion 14 between the optical element surface 12 and the sheet holding head 20 is not touched. Light 41 is irradiated from the optical element surface 13 (step 102), and position information of the contact location 14 is read from the distribution of the reflected light 42 (step 103). In steps 102 and 103, for example, a first imaging unit 40 including a light source 43 and a camera 44 is used. The steps 101 to 103 may be performed in any order as long as the position information of the contact location 14 can be finally read. For example, all of the steps 101 to 103 may be performed simultaneously. Further, the non-optical element surface 13 is brought into contact with the sheet holding head 20, the light 41 is irradiated from the optical element surface 12 to the contact portion between the non-optical element surface 13 and the sheet holding head 20, and the reflected light 42 is distributed. It is good also as reading the positional information on a contact location from.

  Step 104 (FIG. 1 [B ′]): The position information of the panel mark 31 attached to the display panel 30 is read. In step 104, for example, the second imaging unit 50 including the light source 53 and the camera 54 is used. For example, the imaging unit 50 irradiates the panel mark 31 attached to the display panel 30 with light 51 and reads position information of the panel mark 31 from the transmitted light 52. Step 104 may be performed before, after, or simultaneously with steps 101 to 103, or may be omitted if the position information of the panel mark 31 is known.

  Step 105 (FIG. 1C): The positions of the optical sheet 10 and the display panel 30 are aligned based on the position information of the contact location 14 and the position information of the panel mark 31. A general alignment technique may be used for this alignment.

  Step 106 (FIG. 1C): The optical sheet 10 and the display panel 30 are bonded together. For example, the optical sheet 10 and the display panel 30 are bonded together by causing the optical sheet 10 and the display panel 30 to move relative to each other while bringing the optical sheet 10 and the display panel 30 into contact with each other. The relative movement of the optical sheet 10 and the display panel 30 means that at least one of the optical sheet 10 and the display panel 30 is moved. A general bonding technique can be used for this bonding.

  According to the first embodiment, by using the reflected light 42 instead of the transmitted light for reading the position information of the optical sheet 10, it is possible to solve the problems in the case of using the transmitted light all at once. The reading accuracy of information can be improved. Therefore, in the optical sheet laminating step, it is possible to achieve high accuracy and improve yield.

  FIG. 3 is a schematic diagram illustrating the bonding apparatus according to the first embodiment. FIG. 4A is a block diagram illustrating the bonding apparatus according to the first embodiment. FIG. 4B is a block diagram illustrating an example of the control unit in FIG. FIG. 5 is a graph illustrating an example of an alignment operation in the bonding apparatus according to the first embodiment. Hereinafter, description will be made based on FIGS. 3, 4, and 5.

  The optical sheet laminating device 60 according to the first embodiment is for laminating the optical sheet 10 to the display panel 30 using the optical sheet laminating method according to the first embodiment. Imaging section 40, second imaging section 50, moving mechanism section 70, and control section 80. The sheet holding head 20 contacts the optical element surface 12 and holds the optical sheet 10. The imaging unit 40 irradiates the contact portion 14 between the optical element surface 12 and the sheet holding head 20 with light 41 from the non-optical element surface 13 and acquires an image 45 of the distribution of the reflected light 42. The imaging unit 50 acquires an image 55 of the panel mark 31 attached to the display panel 30. The moving mechanism unit 70 moves the optical sheet 10 and the display panel 30 in the coordinate space. The control unit 80 reads the position information of the contact location 14 from the image 45 acquired by the imaging unit 40 and also reads the position information of the panel mark 31 from the image 55 acquired by the imaging unit 50, and the position information of the contact location 14 and the panel mark By controlling the moving mechanism unit 70 based on the position information 31, the positions of the optical sheet 10 and the display panel 30 are matched, and the optical sheet 10 and the display panel 30 are bonded.

  The moving mechanism unit 70 includes an optical sheet side mechanism 71 and a display panel side mechanism 74. The optical sheet side mechanism 71 includes, for example, a linear motor mechanism (or stepping motor and screw feed mechanism) and a rotation mechanism, and is divided into a fixed main body 72 and a head stage 73 movable with respect to the main body 72. The head stage 73 can move the sheet holding head 20 linearly in the X axis direction, the Y axis direction, and the Z axis direction, and can rotate the sheet holding head 20 in the θ direction around the Z axis. The display panel side mechanism 74 includes, for example, a linear motor mechanism (or a stepping motor and a screw feed mechanism), and is divided into a fixed main body 75 and a panel stage 76 movable with respect to the main body 75. The panel stage 76 mounts the display panel 30 and can move linearly in the X-axis direction and the Y-axis direction, respectively. Since the head stage 73 and the panel stage 76 only need to move relatively, for example, the panel stage 76 may be in charge of movement in the Z-axis direction and rotation in the θ direction, and either the head stage 73 or the panel stage 76 may be used. Only one side may be in charge of movement in the Y-axis direction. Further, the moving mechanism unit 70 may move either the optical sheet 10 or the display panel 30 in the coordinate space. In that case, either the optical sheet side mechanism 71 or the display panel side mechanism 74 is omitted. May be.

  The control unit 80 includes, for example, a general computer including a CPU 81, a ROM 82, a RAM 83, an input / output interface 84, and the like, and operates according to a computer program and data. The control unit 80 inputs the images 45 and 55 from the imaging units 40 and 50, reads the position information of the contact location 14 and the position information of the panel mark 31 by an image processing program or the like, and a control signal 85 based on these information. , 86, 87 are output to the sheet holding head 20, the optical sheet side mechanism 71, and the display panel side mechanism 74, respectively. The control signal 85 includes a signal for instructing the sheet holding head 20 to start or end the holding of the optical sheet 10. The control signal 86 includes a signal for moving the head stage 73 (that is, the optical sheet 10) to a desired coordinate. The control signal 87 includes a signal for moving the head stage 73 (that is, the display panel 30) to a desired coordinate. As an example of the computer program of the control unit 80, a procedure for reading the position information of the contact location 14 from the image 45 acquired by the imaging unit 40 and a procedure for reading the position information of the panel mark 31 from the image 55 acquired by the imaging unit 50. Then, by controlling the moving mechanism unit 70 based on the position information of the contact location 14 and the position information of the panel mark 31, the position with the optical sheet 10 display panel 30 is aligned, and the optical sheet 10 and the display panel 30 are pasted. This is for causing the computer to execute the matching procedure.

  Here, an example of the alignment operation of the bonding apparatus 60 will be described. First, the positions and magnifications of the cameras 44 and 54 are adjusted so that the pixels of the cameras 44 and 54 have a one-to-one correspondence with the coordinates on the XY plane. Then, as shown in FIG. 5, the position information of the contact location 14 is obtained as Ma1 (xa1, ya1), Ma2 (xa2, ya2), and the position information of the panel mark 31 is Mb1 (xb1, yb1), Mb2 (xb2 , Yb2). Ma1 and Ma2 are the coordinates of the vertices at both ends of a specific cylindrical lens 11. Mb1 and Mb2 are the coordinates of the two cross-shaped panel marks 31. At this time, the center Mao of the straight line Ma connecting the point Ma1 and the point Ma2 and the center Mbo of the straight line Mb connecting the point Mb1 and the point Mb2 are matched, and the inclinations of the straight line Ma and the straight line Mb are matched. The movement mechanism unit 70 is controlled (that is, the angle θa = 0).

  Next, the first embodiment will be described in more detail.

  The optical sheet 10 that is a lenticular lens sheet is used in a display device that provides image display directed to a plurality of viewpoints. The optical sheet 10 is in contact with the display surface of the display panel 30 and has a wavelength of at least part of light in the visible light region. Is transparent. The material of the optical sheet 10 may be any material as long as it transmits at least part of light having a wavelength of 400 nm to 800 nm, and may be an inorganic material or an organic material. As the inorganic material, glass or the like can be used, and as the organic material, plastic or the like can be used. In general, plastic is often used. As the plastic, engineering plastics such as polymethyl methacrylate (PMMA), cyclopolyolefin (COP), and polycarbonate (PC) can be used. The thickness of the optical sheet 10 is not particularly limited, but is preferably about 0.05 mm to 0.5 mm from a practical viewpoint.

  In FIG. 1, the outline of an example of the bonding process of the optical sheet in this Embodiment 1 is shown. First, as shown in FIG. 1A, the optical sheet 10 is held using the sheet holding head 20. Next, as shown in FIG. 1B, the light 41 is irradiated from the light source 43 toward the contact location 14, the distribution of the reflected light 42 is captured by the camera 44, and the obtained image 45 is used for optical processing. The position information of the sheet 10 is read. At the same time, as shown in FIG. 1B ′, the position information of the panel mark 31 (see also FIG. 20) on the display panel 30 is read using the camera 54. Thereafter, as shown in FIG. 1C, based on the positional information of both, the sheet holding head 20 that holds the optical sheet 10 and the panel stage 76 (see FIG. 3) that fixes the display panel 30 are placed at predetermined positions. The alignment operation | movement which aligns is performed and the optical sheet 10 and the display panel 30 are bonded together.

  Here, the panel mark 31 (see also FIG. 20) is read by the transmitted light 52. However, if the material constituting the panel mark has a predetermined reflection characteristic, it can also be read by the reflected light. Various operations can be used as the alignment operation. For example, when the sheet holding head 20 is movable to an arbitrary position and the panel stage 76 (see FIG. 3) is fixed, when the panel stage 76 is movable to an arbitrary position and the sheet holding head 20 is fixed, the sheet holding head 20 and the panel stage 76 can be used in any case, such as when both are movable to an arbitrary position (the first embodiment).

  6A and 6B are an image and a side view showing a contact portion between the sheet holding head and the optical element surface of the optical sheet in the first embodiment. 7A is another example of an image showing a contact portion between the sheet holding head and the optical element surface of the optical sheet in Embodiment 1, and FIG. 7B is a non-optical element of the sheet holding head and the optical sheet. It is a side view which shows the state which made the surface contact. Hereinafter, description will be made based on FIGS. 1, 6, and 7.

  FIG. 6 shows an image 45 when the contact portion 14 between the optical element surface (lens surface) 12 of the optical sheet (lenticular lens sheet) 10 and the sheet holding head 20 is imaged using the reflected light 42. The apex of the cylindrical lens 11 forming the lenticular lens sheet and the sheet holding head 20 are in linear contact with each other to form a contact portion 14, and a plurality of contact portions 14 are periodically formed according to the period of the cylindrical lens 11. ing. When these contact locations 14 are irradiated with light 41, the light is strongly reflected at the contact locations 14. Therefore, an image 45 having a large contrast can be obtained as shown in FIG. 6 as compared to the case where the lenticular lens sheet is imaged with transmitted light as in Related Art 2 (see FIG. 8 of Patent Document 1).

  At this time, as shown in FIG. 7A, position information of at least two points (for example, points Ma1 and Ma2) is read in the longitudinal direction of the cylindrical lens 11, and the position and the position are obtained using a linear function connecting the two points. The position information necessary for the alignment operation between the optical sheet 10 and the display panel 30 can be obtained by obtaining the inclination. In order to improve the reading accuracy, it is possible to read three or more points, apply a least square method to these three points to obtain a function, and use this function to obtain the position and inclination. Note that the two points (points Ma1 and Ma2) are located at the extreme end portion (right end portion in FIG. 7A) with respect to the lens pitch direction of the optical sheet 10 for convenience in FIG. 7A, but are not limited thereto. Instead, the position of what is inside from the end may be used.

  FIG. 7B is a schematic diagram when the non-optical element surface (non-lens surface) 13 of the optical sheet 10 and the sheet holding head 20 are brought into contact with each other. In this case, the captured image by the reflected light has a distribution corresponding to the lens imaging performance.

  As the light source 43, various light sources such as LED illumination and fluorescent lamp illumination can be used, and the wavelength can be arbitrarily set according to the spectral sensitivity characteristics of the CCD in the camera 44. The same applies to the light source 53.

  As shown in FIG. 1A, in order to pick up the optical sheet 10 using the sheet holding head 20, techniques such as vacuum adsorption, electrostatic adsorption, and adhesion are used. In the first embodiment, since the position information of the cylindrical lens 11 is read using the reflected light 42, the material of the sheet holding head 20 is not limited. For example, in the case of using vacuum suction, a material excellent in processability, a porous material, a low surface hardness material that suppresses damage to the optical sheet 10 and the like can be applied to form the suction holes. In the case of using adhesive, an elastomer made of rubber or synthetic resin can be applied. In any case, a light-transmitting material is not necessary, and the sheet holding head 20 having high functionality can be provided at a lower cost than when using transmitted light.

  In particular, the sheet holding head 20 in which the holding surface 21 that is in contact with the optical sheet 10 is covered with an elastomer serves as a lens pickup using the adhesive force of the elastomer, and is suitable for bonding the optical sheet 10 and the display panel 30 together. Technology. Bonding using this adhesive elastomer has the effect of making the pressure applied to the optical sheet 10 during the bonding uniform over the entire sheet due to the elasticity of the elastomer, and suppressing the deformation of the cylindrical lens 11 due to the pressure application. .

  At this time, if the adhesive strength of the elastomer is too weak, the optical sheet 10 cannot be held, and if it is too strong, the optical sheet 10 cannot be peeled off from the elastomer. Therefore, in order to hold the optical sheet 10, it is necessary to use an elastomer having an appropriate range of adhesive strength. Since the magnitude of the adhesive force greatly depends on the contact area between the optical element and the elastomer, an adhesive force corresponding to the contact area is required. For example, when the contact portion 14 such as a fly-eye lens sheet or a prism sheet is a point contact, an elastomer having an adhesive force in a range from 1.0 N / 20 mm to 500 N / 20 mm is desirable. When the contact point 14 such as a lenticular lens sheet is a line contact, an elastomer having an adhesive force in a range from 0.1 N / 20 mm to 100 N / 20 m is desirable.

  Moreover, if the pressure at the time of bonding is too small, bubbles are generated in the contact surface between the optical sheet 10 and the display panel 30, and if it is too large, the optical sheet 10 is deformed or damaged, or the display panel 30 is damaged. Therefore, it is necessary to bond the applied pressure within an appropriate range. Since the magnitude of the applied pressure largely depends on the rigidity of the optical sheet 10 and the display panel 30, an applied pressure corresponding to the rigidity is required. For example, when a plastic lenticular lens sheet having a thickness of 0.2 mm is bonded to a liquid crystal display panel having a total thickness of 1.0 mm, it is desirable to set the applied pressure in a range from 0.01 MPa to 1.0 MPa.

  In the example shown in FIG. 8A, in the position information reading process of the optical sheet 10 held by the sheet holding head 20, a plurality of positions are read in order to read the position information of the plurality of cylindrical lenses 11 in the optical sheet 10 more accurately. Cameras 44a and 44b (and a plurality of light sources 43a and 43b as necessary) are provided in the lens pitch direction. The reason for this is that the accuracy of the above-mentioned linear function can be improved by using not only the position information of the single cylindrical lens 11 but also the position information of the plurality of cylindrical lenses 11, and the distance from the distance in the pitch direction. This is because the pitch accuracy can be calculated. As shown in FIG. 1B, in order to obtain the same effect with one camera 44, it is necessary to move the camera 44 or the sheet holding head 20 in order to read the positions of the plurality of cylindrical lenses 11. On the other hand, if there are a plurality of cameras 44a and 44b, such a movement is unnecessary, so that the bonding process can be shortened. Further, when a plurality of cameras 44a and 44b are provided, it is desirable to read position information of both cylindrical lenses 11 located at both ends as much as possible with respect to the lens pitch direction. This is because the accuracy of the fluctuation amount of the read lens pitch is improved as the separation distance in the pitch direction is increased.

  By performing the reading of the position information of the optical sheet 10 shown in FIG. 1B and the reading of the position information of the panel mark 31 shown in FIG. 1B in parallel, it is possible to shorten the bonding process time. . At the time of bonding shown in FIG. 1C, the sheet holding head 20 is placed on the display panel 30 as shown in FIG. 8B so that air bubbles do not enter between the optical sheet 10 and the display panel 30. It is desirable to bond them at an angle.

  As an adhesive material for bonding the optical sheet 10 and the display panel 30, a thermosetting adhesive, an ultraviolet curable adhesive, a visible light curable adhesive, or the like can be used. A UV curable adhesive or a visible light type adhesive having a small size is desirable. In addition to the adhesive, a double-sided transparent adhesive film having a pressure-sensitive adhesive can also be applied. The double-sided transparent adhesive film has the advantages that no thermal load acts and no adhesive sticks out of the lens end face.

  In the example shown in FIG. 8C, the sheet holding head 20 is provided below the display panel 30. Even in this state, the optical sheet 10 and the display panel 30 can be bonded together as in the example shown in FIG.

[Embodiment 2]
FIG. 9 illustrates a sheet holding head according to the second exemplary embodiment, FIG. 9A is a perspective view, and FIGS. 9B and 9C are schematic views illustrating a position information reading operation. Hereinafter, a description will be given based on FIG.

  The second embodiment is characterized in that the holding surface 21a of the sheet holding head 20a has a curved shape. FIG. 9A shows an example of a curved holding surface 21a. In the sheet holding head 20a, the holding surface 21a holding the optical sheet 10 has an arc shape with a curvature. Here, it is desirable that a plurality of cameras 44a and 44b (and light sources 43a and 43b as necessary) be provided.

  In the second embodiment, the shape of the holding surface 21a of the sheet holding head 20 is an arc shape, but any other shape may be used as long as the surface holding the optical sheet 10 is a curved surface. However, since the radius of curvature of the arc shape is constant regardless of the rotation angle, setting of the camera position for reading the position information of the lenticular lens sheet described later, reading control, setting of the rotation axis for bonding, bonding control, etc. Has the advantage of being simple.

  As shown in FIGS. 9B and 9C, by rotating the sheet holding head 20a having the arc-shaped holding surface 21a, the position information of the optical sheet 10 is changed according to the rotation angle without moving the camera 44. You can get more than one. In the second embodiment, a rotation mechanism 77 is provided between the sheet holding head 20a and the head stage 73 (FIG. 3). The rotation mechanism 77 includes, for example, a motor and a reduction gear, and rotates the sheet holding head 20a around the rotation shaft 78. Similarly to the head stage 73 (FIG. 3) and the like, the rotation mechanism 77 also operates according to instructions from the control unit 80 (FIG. 4).

  FIG. 10 is a schematic diagram showing a bonding process in the second embodiment, and the processes proceed in the order of FIGS. 10A, 10B, and 10C. Hereinafter, a description will be given with reference to FIG.

  As shown in FIG. 10, the optical sheet 10 held using the sheet holding head 20a is brought into contact with the display panel 30, and the display panel 30 is synchronized with the rotation while rotating the rotation shaft 78 of the sheet holding head 20a. Alternatively, by rotating the rotation shaft 78 itself, the optical sheet 10 can be bonded to the display panel 30 continuously from the end of the optical sheet 10 toward the opposite end.

  At this time, as shown in FIG. 10A, before the sheet holding head 20a rotates, the portion holding the optical sheet 10 is not brought into contact with the display panel 30, and the sheet holding head 20a is rotated from this state. Then, it is desirable to start bonding the optical sheet 10 as shown in FIG. When the optical sheet 10 and the display panel 30 are brought into contact before the sheet holding head 20a rotates, the adhesive for bonding the contact surface is biased due to a slight difference in applied pressure between before rotation and during rotation. This may generate bubbles. Further, at the end of pasting, after the optical sheet 10 is bonded to the entire surface of the display panel 30, the sheet holding head is kept until the sheet holding head 20a is completely separated from the optical sheet 10 as shown in FIG. It is desirable to rotate 20a. This also has the effect of reducing the generation of bubbles, as in the case of starting to paste.

  FIG. 11 is a perspective view showing a part of the bonding process in the second embodiment, and FIG. 11A is a diagram in which the contact portion between the sheet holding head and the optical sheet is parallel to the arc tangent direction of the sheet holding head. FIG. 11B shows a case where the contact portion between the sheet holding head and the optical sheet is orthogonal to the arc tangent direction of the sheet holding head. Hereinafter, a description will be given based on FIGS. 10 and 11.

  When the optical sheet 10 is held by the sheet holding head 20a, it is desirable that the longitudinal direction of the lens pitch and the tangential direction of the arc are parallel. In this case, as shown in FIG. 11A, when the optical sheet 10 and the display panel 30 are bonded to each other, the contact portion 14 between the sheet holding head 20a and the optical sheet 10 always exists. Power stabilizes. On the other hand, when the lens pitch longitudinal direction and the tangential direction are orthogonal to each other as shown in FIG. 11B, when the optical sheet 10 and the display panel 30 are bonded together, the sheet holding head 20a and the optical sheet 10 Will be orthogonal to the tangential direction of the arc (ie, the bonding direction). When the sheet holding head 20a is rotated at the time of bonding, a portion where the contact portion 14 between the optical sheet 10 and the sheet holding head 20a does not exist is generated according to the period of the lens pitch, and the applied pressure becomes uneven. Bubbles may be generated. Further, stress concentration acts on the valley portion of the cylindrical lens 11, and in the worst case, a crack may occur in the cylindrical lens 11.

  In the second embodiment, the linear bubbles between the optical sheet 10 and the display panel 30 can be greatly relieved by bonding using the sheet holding head 20a. In the sheet holding head 20a, since the optical sheet 10 is held in a warped state, it is not possible to take a method of overlapping and bonding the panel marks 31 of the display panel 30. For this reason, position information of the optical sheet 10 in the present invention is not possible. It is extremely useful to capture the position information of the panel mark 31 separately.

  When the radius of curvature of the sheet holding head 20a is small, the holding force is reduced due to the rigidity of the optical sheet 10, and when it is large, the effect of relaxing the linear bubbles is reduced. For this reason, the radius of curvature of the sheet holding head 20a is desirably in the range of 50 mm to 500 mm. However, considering the distance from the rotary shaft 78 to the leading edge of the sheet holding head 20a, which is a determinant of the height of the laminating apparatus, the radius of curvature is preferably in the range of 50 mm to 200 mm.

  FIG. 12 shows a state in which the sheet holding head 20 a is provided on the lower side with respect to the display panel 30. Even in this state, the optical sheet 10 and the display panel 30 can be bonded together as described above.

[Embodiment 3]
In the third embodiment, an example of a bonding method is described in which the pitch accuracy of at least two positions of the optical sheet held by the arc-shaped sheet holding head is read and the pitch accuracy is corrected according to the read result.

  FIG. 13 is a graph showing an example of the relationship between the bonding pressure and the lens pitch fluctuation amount before and after bonding when the method described in the second embodiment is used. In this example, the bonding pressure and the lens pitch fluctuation amount are substantially linear. However, the relationship between the bonding pressure and the amount of lens pitch variation also depends on the mechanical specifications such as the thickness and elastic constant of the lenticular lens sheet and the bonding method of the sheet holding head configuration and materials. It is grasped beforehand as a graph like 13. Hereinafter, the lens pitch fluctuation amount is represented by “ΔL”.

  First, before the lenticular lens sheet bonding step, the positional information of the lenticular lens sheet held by the sheet holding head corresponds to the start of bonding of the end portions in the lens longitudinal direction as shown in FIG. The lens pitch L1 in the portion (AA portion) and the lens pitch L2 in the portion (BB portion) corresponding to the end of bonding at the other end are read. Next, L1 and L2 are obtained as a difference with respect to the original lens pitch L0, ΔL1 = L1-L0, ΔL2 = L2-L0. Here, it is assumed that ΔL1 = −20 ppm and ΔL2 = −60 ppm. Next, referring to FIG. 14B, the sheet holding head is adjusted so that P1 becomes a bonding pressure necessary to correct 0 ppm and P2 becomes a bonding pressure necessary to correct 60 ppm. The bonding pressure is set according to the rotation angle. Then, as shown in FIG. 14C, the bonding pressure corresponding to this setting is applied from the point AA to the point BB to optimize the lens pitch after the bonding.

  It should be noted that the position where the lens pitch is read is not limited to the two points of the start and end of attachment, but may be three or more. In particular, in the case where the lens pitch is not uniform as shown in FIG. 15A, the CC portion as shown in FIG. 15B is inflected by reading the CC portion in the middle in the lens longitudinal direction. The applied pressure control as a point becomes possible, and the lens pitch correction effect becomes larger. As described above in Embodiment 1, it is naturally possible to perform pitch correction using a function based on the least square method (FIG. 15 [C]).

  As a method of varying the applied pressure, it is desirable to set the pressure by changing the pushing amount of the sheet holding head (for example, using the movement in the Z-axis direction by the head stage 73 in the configuration of FIG. 3). . In this case, since the relationship between the amount of pressing and the pressure acting on the panel changes depending on the method such as adsorption and adhesion as described above and the material constituting the sheet holding head, it is desirable to grasp the relationship in advance. . It is also possible to use pressure variable means such as a pneumatic cylinder. However, in the pressure variable means, the pressure adjustment may be delayed with respect to the attaching speed, so that the simple pressure control is easier when the pushing amount is changed.

  In the third embodiment, even a lenticular lens sheet with a non-uniform lens pitch can be bonded with high accuracy, so that not only a high-accuracy bonding method is provided, but also the pitch tolerance during lens manufacturing increases, so that the yield is improved. Significantly contributes to cost reduction.

[Embodiment 4]
In the fourth embodiment, an example of a method for reading the pitch accuracy at a specific position of the lenticular lens sheet held by the sheet holding head will be described.

  FIG. 16B shows an example of an optical sheet (lenticular lens sheet) 10a used in the fourth embodiment. At least one non-periodic portion 15 having a different period of the cylindrical lens 11 is provided at the end in the lens pitch direction as a mark for reading the position information of the optical sheet 10a. That is, there are portions (two non-periodic portions 15) having different periods of the cylindrical lens 11 at both ends in at least one direction of the optical sheet 10a. FIG. 16A shows an example of an image obtained by irradiating the contact portion 14 with the optical sheet 10a and the sheet holding head 20 and imaging the reflected light. In the first to third embodiments, the contact portion 14 of the arbitrary cylindrical lens 11 is read. On the other hand, in the fourth embodiment, if there is a clear specific position of the non-periodic portion 15, the pitch of the specific position of the optical sheet 10a can be read. Here, also in the fourth embodiment, in order to read the contact location 14, the cross section of the non-periodic portion 15 may be any shape as long as it is lower than the height of the cylindrical lens 11, and may not be flat.

  As a modification, FIG. 17A shows an example of the optical sheet (lenticular lens sheet) 10b. At least one notch 16 is provided at a corner of the optical sheet 10b as a mark for reading the positional information of the optical sheet 10b. FIG. 17B shows an example of an image obtained by irradiating the contact portion 14 with the optical sheet 10b and the sheet holding head 20 used in the present invention and capturing the reflected light. A cutout portion 16 is provided at a corner portion of the cylindrical lens 11 as a mark for reading position information of the optical sheet 10b. The pitch at a specific position of the optical sheet 10b can be read.

  In the description of FIG. 7 of the first embodiment, it has been described that the two points Ma1 and Ma2 of the cylindrical lens 11 do not have to be the endmost portion of the optical sheet 10. This is because the contact portion 14 between the optical sheet 10 and the sheet holding head may be as shown in FIG. 18B. As shown in FIG. 18A, for example, when the outer shape of a lenticular lens sheet is formed by a die cutting process or a cutting process, a slight rotational deviation may occur in a cutting line parallel to the longitudinal direction of the cylindrical lens 11. is there. In particular, in a high-definition lenticular lens sheet having a pitch of 200 μm or less, a predetermined number of lenses may be lost depending on the pitch. For this reason, an image of the contact portion 14 of the cylindrical lens 11 in an arbitrary pitch direction inside from the end is used in anticipation of the defect portion.

  However, in this image, only the contact location due to the repetition of the specific period appears, so that it is difficult to specify the reading position with respect to the outer shape of the lenticular lens sheet. Therefore, the number of dummy cylindrical lenses that is greater than or equal to the number lost by cutting is required, but in this uncertain reading state, a considerable number of dummy lenses is required. As a result, the outer shape of the lenticular lens sheet becomes considerably larger than the display panel.

  On the other hand, since the specific position of the lenticular lens sheet is grasped in the fourth embodiment, only the number of dummy lenses that are lost by cutting is sufficient, and the outer shape of the lenticular lens sheet is slightly larger than the display panel. It becomes. For this reason, it greatly contributes to narrowing the frame of the display device using this method.

[Embodiment 5]
FIG. 19A is a perspective view showing a portable terminal device 90 equipped with a display device 91 in which an optical sheet is bonded to a display panel using the present invention. As shown in FIG. 19A, the display device 91 is mounted on a mobile terminal device 90 such as a mobile phone, for example.

  Although Embodiments 1 to 5 describe the case where a lenticular lens sheet is used as the optical sheet, a fly-eye lens 17 (FIG. 19B), a prism sheet, or the like can be used as the optical sheet. Even when they are used for the optical sheet, the same effects as those of the above embodiments are obtained.

  Although the present invention has been described with reference to the above embodiments, the present invention is not limited to the above embodiments. Various changes that can be understood by those skilled in the art can be made to the configuration and details of the present invention. Further, the present invention includes a combination of some or all of the configurations of the above-described embodiments as appropriate.

  Next, the present invention will be summarized. The film laminating method of the present invention is an optical sheet laminating method in which an optical sheet on which a plurality of optical elements are formed is bonded to a display panel on which a plurality of electro-optical elements are formed using a sheet holding head. The optical element surface of the optical sheet is brought into contact with the sheet holding head, the contact portion is irradiated with light from the non-optical element surface of the optical sheet, and the distribution of reflected light is determined using the first imaging means. Based on the first reading step for reading the contact portion between the optical element and the sheet holding head and the first reading step, the optical sheet and the display panel are aligned, and the sheet holding head is set to a predetermined position. An alignment step of moving the optical sheet and the display panel, and then bringing the sheet holding head and the display panel into a relative position. It is to movement, characterized by having the bonding the optical sheet and the display panel process.

  According to this configuration, since the position information of the optical sheet is read using the reflected light, the sheet holding head does not need to have translucency, and the material of the head is not limited. For example, in the case of a stereoscopic display device in which a lenticular lens sheet is bonded, the positional relationship between the vertex of the lens surface of the lenticular lens sheet and the pixel of the display panel is important. By reading the contact portion between the optical sheet and the sheet holding head as in the present invention, the apex portion of the lens surface can be reliably recognized, so the positional information reading accuracy of the optical sheet necessary for optical sheet bonding is high. improves. Even if the curvature radius of each lens varies greatly or the lens film itself is distorted, the apex of the lens surface of the lenticular lens sheet will not contact the sheet holding head, so the reading accuracy will deteriorate. do not do.

  The film laminating method of the present invention is an optical sheet laminating method in which an optical sheet on which a plurality of optical elements are formed is bonded to a display panel on which a plurality of electro-optical elements are formed using a sheet holding head. The non-optical element surface of the optical sheet is brought into contact with the sheet holding head, the contact portion is irradiated with light from the optical element surface of the optical sheet, and the distribution of reflected light is determined using the first imaging unit. Based on the first reading step for reading the contact portion between the optical element and the sheet holding head and the first reading step, the optical sheet and the display panel are aligned, and the sheet holding head is set to a predetermined position. An alignment step of moving the optical sheet and the display panel, and then bringing the sheet holding head and the display panel into a relative position. It is to movement, characterized by having the bonding the optical sheet and the display panel process.

  The optical element may be a cylindrical lens that is a convex lens having a cylindrical surface, and the optical sheet may be a lenticular lens sheet film in which a plurality of cylindrical lenses are arranged at the same lens pitch. Alternatively, the optical element is a fly-eye lens that is a convex lens having a cylindrical surface, and the optical sheet has a second direction in which the fly-eye lens is orthogonal to the first direction. A fly-eye lens film having a plurality of lens surfaces arranged at independent lens pitches in each direction may be used.

  The sheet holding head may have an arcuate shape with a curvature, and a surface for holding the optical sheet may be a curved surface. By bonding using an arc-shaped sheet holding head, linear bubbles generated between the optical sheet and the display panel can be suppressed. At this time, the lens longitudinal direction of the lenticular lens sheet film and the direction of relative movement for bonding the lenticular lens sheet film using the sheet holding head may be parallel. Further, a tangential direction of an arc of the arc-shaped sheet holding head may be parallel to a lens longitudinal direction of the lenticular lens sheet film, and the lenticular lens sheet film is formed using the arc-shaped sheet holding head. The directions of relative motion for bonding may be parallel.

  The contact surface between the lenticular lens sheet and the sheet holding head is in a state in which the lens apex of the cylindrical lens constituting the lenticular lens sheet and the sheet holding head are in line contact and are periodically arranged. FIG. 11 is a view showing a contact portion 14 between the arc-shaped sheet holding head 20a and the lenticular lens sheet. When the lens longitudinal direction and the bonding direction are parallel (FIG. 11 [A]), since there is always a contact portion at the time of bonding, the bonding can be performed with a stable holding force. . When the lens longitudinal direction and the bonding direction are orthogonal to each other (FIG. 11 [B]), there is a portion where the lenticular lens sheet and the sheet holding head are not in contact with each other periodically at the time of bonding. In some cases, bubbles cannot be mixed without obtaining a stable holding force.

  In the step of bonding the optical sheet and the display panel, the bonding pressure applied to the sheet holding head may not be constant during the relative movement for bonding. Further, in a first reading step of reading a contact portion between the optical element and the sheet holding head, a deviation amount from a design value of the lens pitch of the lens film is calculated, and the optical sheet is based on the calculated result. In the step of bonding the display panel and the display panel, a bonding pressure applied to the sheet holding head may be set. A bonding pressure applied to the sheet holding head may be set by a pressing amount of the sheet holding head with respect to the display panel. In these cases, even if the lens pitch of the lenticular lens sheet varies at the stage before bonding, the lens pitch can be adjusted to an appropriate lens pitch after bonding by adjusting the bonding pressure.

  In the present invention, at least one side of the optical sheet or both ends in one direction may have a portion having a different period of the optical element as a film mark. In addition, a cutout may be provided in at least one corner of the optical sheet. In these cases, by providing a part with a different period in a part of the optical sheet, it is possible to provide a part that is characteristic in the contact part between the optical sheet and the sheet holding head.

  There are at least two photographing cameras constituting the first photographing means in the present invention, and at least two images are obtained in the first reading step, and the images are used in the alignment step. Also good. In order to read the position information of the optical sheet, it is necessary to obtain position information of at least two points. By providing two or more means for obtaining the position information of the optical sheet, it is possible to obtain the necessary position information by one shooting.

  The sheet holding head in the present invention may hold the entire optical sheet including the contact portion used in the first reading step. The surface of the sheet holding head may be covered with an adhesive elastomer, and the optical sheet may be held using the adhesive force of the elastomer. By providing an adhesive elastomer with elasticity on the surface of the sheet holding head, the pressure at the time of bonding can be made uniform. In addition, deformation of the lenticular lens sheet can be mitigated during bonding.

  In the film laminating method in the present invention, the display panel has a panel mark for alignment, and a second reading step of reading the panel mark of the display panel using a second imaging means, and the first An alignment step of aligning the optical sheet and the display panel and moving the sheet holding head to a predetermined position based on the reading step and the second reading step; and the optical sheet and the display panel The sheet holding head and the display panel are moved relative to each other, and then the optical sheet and the display panel are bonded to each other. By reading the position information of the optical sheet and the position information of the display panel by different means, there is no restriction on the position of the display panel mark. For example, in the liquid crystal display device, as shown in FIG. 20, since the panel mark 31 can be arranged near the periphery of the display panel 30 that is away from the optical sheet 10, the influence on the display quality can be reduced.

  Next, the effect of the present invention will be described. In the present invention, since the positional information reading accuracy of the optical sheet is improved, it is possible to provide a highly accurate optical sheet laminating process and to improve the yield of the laminating process. Even if the optical element pitch of the optical sheet fluctuates unevenly in the plane, providing a high-precision optical sheet bonding process and bonding process by performing bonding so that the appropriate optical element pitch is achieved The yield can be improved. Since bubbles and linear bubbles between the optical sheet and the display panel can be prevented, the yield of the optical sheet bonding step can be improved. When a lenticular lens sheet is used as the optical sheet, a high-precision and low-load bonding process can be provided by the sheet holding and bonding direction in consideration of the lens pitch direction. Since there is no restriction on the position of the panel mark necessary for high-precision bonding, display quality can be improved.

  Although a part or all of the above embodiments can be described as the following supplementary notes, the present invention is not limited to the following configurations.

(Supplementary Note 1) An optical sheet having both an optical element surface on which a plurality of optical elements are formed and a non-optical element surface on which the optical elements are not formed is converted into a plurality of electro-optical elements using a sheet holding head. In the bonding method of the optical sheet to be bonded to the formed display panel,
The optical element surface is brought into contact with the sheet holding head, light is irradiated from the non-optical element surface to a contact portion between the optical element surface and the sheet holding head, and a distribution of the reflected light is first imaged. A first reading step of reading the position of the contact portion by obtaining using means;
Based on the position of the contact location read in the first reading step, an alignment step of aligning the optical sheet and the display panel,
A method for laminating an optical sheet, comprising:

(Supplementary note 2) An optical sheet having both an optical element surface on which a plurality of optical elements are formed and a non-optical element surface on which the optical elements are not formed is converted into a plurality of electro-optical elements using a sheet holding head. In the bonding method of the optical sheet to be bonded to the formed display panel,
The non-optical element surface is brought into contact with the sheet holding head, light is irradiated from the optical element surface to a contact portion between the non-optical element surface and the sheet holding head, and the distribution of the reflected light is first A first reading step of reading the position of the contact location by obtaining using an imaging means;
Based on the position of the contact location read in the first reading step, an alignment step of aligning the optical sheet and the display panel,
A method for laminating an optical sheet, comprising:

(Appendix 3) An optical sheet having both an optical element surface on which a plurality of optical elements are formed and a non-optical element surface on which the optical elements are not formed is aligned using a sheet holding head. In the method of laminating an optical sheet that is pasted to a display panel having a mark and a plurality of electro-optic elements formed,
The optical element surface is brought into contact with the sheet holding head, light is irradiated from the non-optical element surface to a contact portion between the optical element surface and the sheet holding head, and a distribution of the reflected light is first imaged. A first reading step of reading the position of the contact portion by obtaining using means;
A second reading step of reading the position of the panel mark using a second imaging means;
By moving the sheet holding head based on the position of the contact portion read in the first reading step and the position of the panel mark read in the second reading step, the optical sheet and An alignment step of aligning with the display panel;
A bonding step of bonding the optical sheet and the display panel by causing the sheet holding head and the display panel to move relative to each other while bringing the optical sheet and the display panel into contact with each other.
A method for laminating an optical sheet, comprising:

(Supplementary Note 4) An optical sheet having both an optical element surface on which a plurality of optical elements are formed and a non-optical element surface on which the optical elements are not formed is aligned using a sheet holding head. In the method of laminating an optical sheet that is pasted to a display panel having a mark and a plurality of electro-optic elements formed,
The non-optical element surface is brought into contact with the sheet holding head, light is irradiated from the optical element surface to a contact portion between the non-optical element surface and the sheet holding head, and the distribution of the reflected light is first A first reading step of reading the position of the contact location by obtaining using an imaging means;
A second reading step of reading the position of the panel mark of the display panel using a second imaging means;
By moving the sheet holding head based on the position of the contact portion read in the first reading step and the position of the panel mark read in the second reading step, the optical sheet and An alignment step of aligning with the display panel;
A bonding step of bonding the optical sheet and the display panel by causing the sheet holding head and the display panel to move relative to each other while bringing the optical sheet and the display panel into contact with each other.
A method for laminating an optical sheet, comprising:

(Appendix 5) In the method for laminating an optical sheet according to Appendix 3 or 4,
The optical element is a cylindrical lens composed of a convex lens having a cylindrical surface,
The optical sheet is a lenticular lens sheet film in which a plurality of the cylindrical lenses are arranged at a predetermined pitch.
An optical sheet laminating method characterized by the above.

(Appendix 6) In the method for laminating an optical sheet according to appendix 3 or 4,
The optical element is a fly-eye lens composed of a convex lens having a cylindrical surface,
The optical sheet is a fly-eye lens film having a lens surface in which a plurality of fly-eye lenses are arranged at a predetermined pitch in a first direction and a second direction perpendicular to each other.
An optical sheet laminating method characterized by the above.

(Appendix 7) In the method for laminating an optical sheet according to Appendix 5,
In the sheet holding head, a surface for holding the optical sheet is an arcuate curved surface (having a predetermined curvature).
An optical sheet laminating method characterized by the above.

(Appendix 8) In the optical sheet laminating method according to appendix 7,
The tangential direction of the arc is parallel to the lens longitudinal direction of the lenticular lens sheet film,
An optical sheet laminating method characterized by the above.

(Appendix 9) In the optical sheet laminating method according to appendix 8,
In the bonding step, the relative motion direction is parallel to the lens longitudinal direction of the lenticular lens sheet film.
An optical sheet laminating method characterized by the above.

(Appendix 10) In the method for laminating an optical sheet according to appendix 9,
In the bonding step, the pressure applied to the optical sheet when the sheet holding head and the display panel are relatively moved is changed during the relative movement.
An optical sheet laminating method characterized by the above.

(Supplementary note 11) In the method for laminating an optical sheet according to supplementary note 10,
In the bonding step, the amount of deviation from the design value of the pitch is obtained based on the position of the contact location read in the first reading step, and the pressure applied to the optical sheet so that the amount of deviation is reduced Set
An optical sheet laminating method characterized by the above.

(Supplementary note 12) In the method for laminating an optical sheet according to supplementary note 11,
In the bonding step, the pressure applied to the optical sheet is set by the pushing amount of the sheet holding head against the display panel.
An optical sheet laminating method characterized by the above.

(Appendix 13) In the method for laminating an optical sheet according to any one of appendices 1 to 12,
At least one side of the optical sheet has a portion where the period of the optical element is different as a film mark,
An optical sheet laminating method characterized by the above.

(Supplementary note 14) In the method for laminating an optical sheet according to any one of supplementary notes 1 to 12,
There are portions where the period of the optical element is different as a film mark at both ends in at least one direction of the optical sheet,
An optical sheet laminating method characterized by the above.

(Supplementary note 15) In the method for laminating an optical sheet according to any one of Supplementary notes 1 to 12,
A cutout is provided in at least one corner of the optical sheet.
An optical sheet laminating method characterized by the above.

(Supplementary note 16) In the method for laminating an optical sheet according to any one of supplementary notes 1 to 15,
There are at least two photographing cameras constituting the first photographing means, and at least two images are obtained during the first reading step, and these images are used in the alignment step.
An optical sheet laminating method characterized by the above.

(Supplementary Note 17) In the method for laminating an optical sheet according to any one of supplementary notes 1 to 16,
The sheet holding head holds the entire optical sheet including the contact location used in the first reading step.
An optical sheet laminating method characterized by the above.

(Appendix 18) In the method for laminating an optical sheet according to any one of appendices 1 to 17,
The surface of the sheet holding head is covered with an adhesive elastomer, and the optical sheet is held using the adhesive force of the elastomer.
An optical sheet laminating method characterized by the above.

(Appendix 19) In the method for laminating an optical sheet according to any one of appendices 1 to 18,
The method for laminating an optical sheet, wherein the display panel is a liquid crystal display panel.

(Supplementary note 20) The method for bonding optical sheets according to any one of supplementary notes 1 to 19, is used.
An optical sheet laminating apparatus.

(Appendix 21) Manufactured by the method of laminating any one of appendices 1 to 19,
A display device characterized by that.

  The present invention is used, for example, in a display device that enables stereoscopic image display, viewing angle control, and the like and a manufacturing technique thereof.

10, 10a, 10b Optical sheet 11 Cylindrical lens (optical element)
DESCRIPTION OF SYMBOLS 12 Optical element surface 13 Non-optical element surface 14 Contact location 15 Aperiodic part 16 Notch part 17 Fly eye lens 20, 20a Sheet holding head 21, 21a Holding surface 30 Display panel 31 Panel mark 40 Imaging part (1st imaging part) )
41, 51 Light 42 Reflected light 43, 43a, 43b, 53 Light source 44, 44a, 44b, 54 Camera 45, 55 Image 50 Imaging unit (second imaging unit)
52 Transmitted Light 60 Bonding Device 70 Moving Mechanism Unit 71 Optical Sheet Side Mechanism 72, 75 Main Body 73 Head Stage 74 Display Panel Side Mechanism 76 Panel Stage 77 Rotating Mechanism 78 Rotating Shaft 80 Control Unit 90 Portable Terminal Device 91 Display Device

Claims (17)

Bonding of an optical sheet in which an optical sheet having both an optical element surface on which a plurality of optical elements are formed and a non-optical element surface on which the optical element is not formed is bonded to a display panel using a sheet holding head In the method
Contacting one of the optical element surface and the non-optical element surface with the sheet holding head;
Irradiating light from the other of the optical element surface and the non-optical element surface to a contact portion between one of the optical element surface and the non-optical element surface and the sheet holding head,
Read the position information of the contact location from the distribution of the reflected light,
Based on the position information of this contact location, align the position of the optical sheet and the display panel, the optical sheet and the display panel are bonded together,
The optical element is a cylindrical lens composed of a convex lens having a cylindrical surface,
The optical sheet is a lenticular lens film in which a plurality of the cylindrical lenses are arranged at a predetermined pitch,
After reading the position information of the contact location, based on the position information of the contact location, determine the amount of deviation from the design value of the pitch,
When bonding the optical sheet and the display panel, to set the pressure applied to the optical sheet so that the amount of deviation is small,
An optical sheet laminating method characterized by the above. Bonding of an optical sheet in which an optical sheet having both an optical element surface on which a plurality of optical elements are formed and a non-optical element surface on which the optical element is not formed is bonded to a display panel using a sheet holding head In the method
Contacting one of the optical element surface and the non-optical element surface with the sheet holding head;
Irradiating light from the other of the optical element surface and the non-optical element surface to a contact portion between one of the optical element surface and the non-optical element surface and the sheet holding head,
Read the position information of the contact location from the distribution of the reflected light,
Based on the position information of this contact location, align the position of the optical sheet and the display panel, the optical sheet and the display panel are bonded together,
The optical element is a fly-eye lens composed of a convex lens having a cylindrical surface,
The optical sheet is a fly-eye lens film having a lens surface in which a plurality of the fly-eye lenses are arranged at predetermined pitches in a first direction and a second direction orthogonal to each other,
After reading the position information of the contact location, based on the position information of the contact location, determine the amount of deviation from the design value of the pitch,
When bonding the optical sheet and the display panel, to set the pressure applied to the optical sheet so that the amount of deviation is small,
An optical sheet laminating method characterized by the above. In the bonding method of the optical sheet of Claim 1 or 2,
Read the position information of the panel mark attached to the display panel,
Based on the position information of the contact location and the position information of the panel mark, the position of the optical sheet and the display panel are matched,
The optical sheet and the display panel are bonded together by causing the optical sheet and the display panel to move relative to each other while contacting the optical sheet and the display panel.
An optical sheet laminating method characterized by the above. In the bonding method of the optical sheet of Claim 1,
In the sheet holding head, the surface holding the optical sheet is an arcuate curved surface.
An optical sheet laminating method characterized by the above. In the method for laminating an optical sheet according to claim 4,
The tangential direction of the arc is parallel to the lens longitudinal direction of the lenticular lens film ,
An optical sheet laminating method characterized by the above. In the method for laminating an optical sheet according to claim 3,
In the sheet holding head, the surface holding the optical sheet is an arcuate curved surface,
The tangential direction of the arc is parallel to the lens longitudinal direction of the lens film ,
The direction of the relative motion is parallel to the lens longitudinal direction of the lens film ,
An optical sheet laminating method characterized by the above. In the bonding method of the optical sheet of any one of Claims 1 thru | or 6,
A portion having a different period of the optical element is present on at least one side of the optical sheet.
An optical sheet laminating method characterized by the above. In the bonding method of the optical sheet of any one of Claims 1 thru | or 6,
There are portions where the period of the optical element is different at both ends in at least one direction of the optical sheet,
An optical sheet laminating method characterized by the above. In the bonding method of the optical sheet of any one of Claims 1 thru | or 6,
A cutout is provided in at least one corner of the optical sheet.
An optical sheet laminating method characterized by the above. In the bonding method of the optical sheet of any one of Claims 1 thru | or 9,
Obtaining a plurality of images of the reflected light distribution by a plurality of cameras, and reading the position information of the contact location;
An optical sheet laminating method characterized by the above. In the bonding method of the optical sheet of any one of Claims 1 thru | or 10,
The sheet holding head holds the entire optical sheet including the contact location,
An optical sheet laminating method characterized by the above. In the bonding method of the optical sheet of any one of Claims 1 thru | or 11,
The surface of the sheet holding head is covered with an adhesive elastomer, and the optical sheet is held using the adhesive force of the elastomer.
An optical sheet laminating method characterized by the above. In the bonding method of the optical sheet of any one of Claims 1 thru | or 12,
The method for laminating an optical sheet, wherein the display panel is a liquid crystal display panel. In an optical sheet laminating apparatus for laminating an optical sheet having both an optical element surface on which a plurality of optical elements are formed and a non-optical element surface on which the optical element is not formed, to a display panel,
A sheet holding head for holding the optical sheet in contact with one of the optical element surface and the non-optical element surface;
Light is irradiated from the other of the optical element surface and the non-optical element surface to a contact portion between one of the optical element surface and the non-optical element surface and the sheet holding head, and an image of the reflected light distribution is obtained. A first imaging unit to acquire;
A second imaging unit for acquiring an image of a panel mark attached to the display panel;
A moving mechanism for moving at least one of the optical sheet and the display panel in a coordinate space;
The position information of the contact location is read from the image acquired by the first imaging unit and the position information of the panel mark is read from the image acquired by the second imaging unit, and the position information of the contact location and the By controlling the moving mechanism unit based on the position information of the panel mark, the control unit for aligning the position of the optical sheet and the display panel, and bonding the optical sheet and the display panel;
With
The optical element is a cylindrical lens composed of a convex lens having a cylindrical surface,
The optical sheet is a lenticular lens film in which a plurality of the cylindrical lenses are arranged at a predetermined pitch,
The controller, after reading the position information of the contact location, obtains a shift amount from the design value of the pitch based on the position information of the contact location, and when the optical sheet and the display panel are bonded together Setting the pressure applied to the optical sheet so that the amount of deviation is small,
An optical sheet laminating apparatus characterized by the above. In a program used for an optical sheet laminating apparatus for laminating an optical sheet having both an optical element surface on which a plurality of optical elements are formed and a non-optical element surface on which the optical element is not formed to a display panel ,
The laminating apparatus is
A sheet holding head for holding the optical sheet in contact with one of the optical element surface and the non-optical element surface;
Light is irradiated from the other of the optical element surface and the non-optical element surface to a contact portion between one of the optical element surface and the non-optical element surface and the sheet holding head, and an image of the reflected light distribution is obtained. A first imaging unit to acquire;
A second imaging unit for acquiring an image of a panel mark attached to the display panel;
A moving mechanism for moving at least one of the optical sheet and the display panel in a coordinate space;
A control unit including a computer,
The optical element is a cylindrical lens composed of a convex lens having a cylindrical surface,
The optical sheet is a lenticular lens film in which a plurality of the cylindrical lenses are arranged at a predetermined pitch,
In the computer,
Reading the position information of the contact location from the image acquired by the first imaging unit, and obtaining a deviation amount from the design value of the pitch based on the position information of the contact location;
A procedure for reading position information of the panel mark from the image acquired by the second imaging unit;
The position of the optical sheet and the display panel is aligned by bonding the optical sheet and the display panel by controlling the moving mechanism based on the position information of the contact location and the position information of the panel mark. In addition, when the optical sheet and the display panel are bonded together, a procedure for setting a pressure applied to the optical sheet so that the amount of deviation is small;
A program for running In an optical sheet laminating apparatus for laminating an optical sheet having both an optical element surface on which a plurality of optical elements are formed and a non-optical element surface on which the optical element is not formed, to a display panel,
A sheet holding head for holding the optical sheet in contact with one of the optical element surface and the non-optical element surface;
Light is irradiated from the other of the optical element surface and the non-optical element surface to a contact portion between one of the optical element surface and the non-optical element surface and the sheet holding head, and an image of the reflected light distribution is obtained. A first imaging unit to acquire;
A second imaging unit for acquiring an image of a panel mark attached to the display panel;
A moving mechanism for moving at least one of the optical sheet and the display panel in a coordinate space;
The position information of the contact location is read from the image acquired by the first imaging unit and the position information of the panel mark is read from the image acquired by the second imaging unit, and the position information of the contact location and the By controlling the moving mechanism unit based on the position information of the panel mark, the control unit for aligning the position of the optical sheet and the display panel, and bonding the optical sheet and the display panel;
With
The optical element is a fly-eye lens composed of a convex lens having a cylindrical surface,
The optical sheet is a fly-eye lens film having a lens surface in which a plurality of the fly-eye lenses are arranged at predetermined pitches in a first direction and a second direction orthogonal to each other,
The controller, after reading the position information of the contact location, obtains a shift amount from the design value of the pitch based on the position information of the contact location, and when the optical sheet and the display panel are bonded together Setting the pressure applied to the optical sheet so that the amount of deviation is small,
An optical sheet laminating apparatus characterized by the above. In a program used for an optical sheet laminating apparatus for laminating an optical sheet having both an optical element surface on which a plurality of optical elements are formed and a non-optical element surface on which the optical element is not formed to a display panel ,
The laminating apparatus is
A sheet holding head for holding the optical sheet in contact with one of the optical element surface and the non-optical element surface;
Light is irradiated from the other of the optical element surface and the non-optical element surface to a contact portion between one of the optical element surface and the non-optical element surface and the sheet holding head, and an image of the reflected light distribution is obtained. A first imaging unit to acquire;
A second imaging unit for acquiring an image of a panel mark attached to the display panel;
A moving mechanism for moving at least one of the optical sheet and the display panel in a coordinate space;
A control unit including a computer,
The optical element is a fly-eye lens composed of a convex lens having a cylindrical surface,
The optical sheet is a fly-eye lens film having a lens surface in which a plurality of the fly-eye lenses are arranged at predetermined pitches in a first direction and a second direction orthogonal to each other,
In the computer,
Reading the position information of the contact location from the image acquired by the first imaging unit, and obtaining a deviation amount from the design value of the pitch based on the position information of the contact location;
A procedure for reading position information of the panel mark from the image acquired by the second imaging unit;
The position of the optical sheet and the display panel is aligned by bonding the optical sheet and the display panel by controlling the moving mechanism based on the position information of the contact location and the position information of the panel mark. In addition, when the optical sheet and the display panel are bonded together, a procedure for setting a pressure applied to the optical sheet so that the amount of deviation is small;
A program for running

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