JP2012181221A - Columnar lens sheet for displaying stereoscopic image and liquid crystal display device using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a columnar lens sheet for displaying a stereoscopic image capable of improving the crosstalk of a left and right parallax image caused by the time-depending dimensional change when a lenticular lens is used for naked eye stereoscopic viewing, and of easily aligning a left parallax image with a right parallax image so as to utilize the dimensional stability, and also to provide a liquid crystal display device using the columnar lens sheet.SOLUTION: The columnar lens sheet 10 for displaying the stereoscopic image has a columnar lens group 3 in which unit columnar lenses 2 are arrayed in one direction da on an extension base film 1, a tilt angle θ between the orientation direction of the molecule main spindle of the base film and the ridge direction dp of the unit columnar lens is 0°≤θ≤50° in all regions, and furthermore on the surface of the columnar lens group located outside an effective screen area A, two or more alignment marks M per one sheet are provided. The liquid crystal display device can display the stereoscopic image by combing this lens sheet with a liquid crystal panel.

Description

The present invention provides a stereoscopic image display columnar lens sheet having a unit columnar lens such as a lenticular lens, which is suitable for various stereoscopic image display device applications, particularly for naked-eye stereoscopic image display that does not require special glasses for stereoscopic vision, and The present invention relates to a liquid crystal display device using the.
Among them, a columnar lens sheet for stereoscopic image display, which is less likely to cause crosstalk between right and left parallax images due to dimensional changes in the lens over time, and is easily positioned so that this feature can be used effectively, and The present invention relates to the liquid crystal display device used.

  In recent years, due to advances in technology such as high-definition display panels, stereoscopic image display for 3D televisions and the like that can display 3D images using flat panel displays such as liquid crystal panels that display 2D images Devices are spreading rapidly. As stereoscopic image display devices that are currently popular, glasses that require glasses are often used as a stereoscopic image display method, but autostereoscopic image display devices that do not require glasses and can be viewed with the naked eye have also been put into practical use. Yes. There is a lenticular system using a lenticular lens as one of the autostereoscopic systems that enables stereoscopic viewing with the naked eye, and various proposals have been made (Patent Documents 1 and 2).

JP-A-6-78342 Japanese Patent Laid-Open No. 10-232369

  By the way, from the viewpoint of cost, ease of manufacture, etc., the lenticular lens is preferably made of resin. Here, when the display panel is a liquid crystal panel (liquid crystal display element), when such a resin lenticular lens is combined with the liquid crystal panel, the arrangement period of the lenticular lens is Subtle dimensional changes due to heat over time. On the other hand, since the front and back substrates are made of glass, the liquid crystal panel has less dimensional change than the resin. For this reason, the relative positions of the pixels of the liquid crystal panel and the arrangement direction of the lenticular lenses (direction orthogonal to the ridge line direction) are shifted with time. However, in order to display a stereoscopic image, the lenticular lens needs to be maintained in a highly accurate positional relationship with the pixels of the liquid crystal panel.

And if the relative positional relationship between the pixels of the liquid crystal panel and the lenticular lens is distorted, the accuracy of sorting the left image and right image displayed on the liquid crystal panel to the left and right eyes by the lenticular lens decreases, and the left and right parallax images So-called crosstalk occurs in which three-dimensional images are deteriorated.
The problem of crosstalk between left and right parallax images is also caused by the movement of the observer's observation position. For this reason, various improvements have been proposed, but the relative positional relationship between the lenticular lens and the pixels of the liquid crystal panel is maintained correctly. This is based on the premise that the lens and the pixels are in a relative positional relationship.

  Moreover, in order to maintain the relative positional relationship between the lens and the pixel, in addition to preventing the dimensional change with time, the lenticular lens is aligned to the correct position with respect to the liquid crystal panel. It is necessary to be assembled.

  That is, the problem of the present invention is that when using a unit columnar lens such as a lenticular lens for autostereoscopic viewing, the dimensional change of the unit columnar lens over time, in particular, the dimensional change in the arrangement direction is reduced, and the right and left parallaxes are reduced. A columnar lens sheet for stereoscopic image display that can be easily aligned and a liquid crystal display device using the same to improve the occurrence of crosstalk of images over time and further utilize the characteristics of dimensional stability. Is to provide.

The present invention provides a stereoscopic image display optical member having the following configuration and a liquid crystal display device using the same.
(1) A columnar lens group having unit columnar lenses arranged in one direction parallel to each other on one surface of a substrate film, and the orientation direction of the molecular principal axis of the resin constituting the substrate film The inclination angle θ defined as an inferior angle among the angles formed by the ridge line direction of the unit columnar lens in a plane parallel to one surface of the base film is 0 ° ≦ θ throughout the base film. ≦ 50 °,
A columnar lens sheet for stereoscopic image display, having at least two alignment marks per sheet on the surface of the columnar lens group outside the effective screen area.
(2) The alignment mark is made of the same material as the columnar lens group, and an interface is formed between the alignment mark and the columnar lens group at a portion where the alignment mark is convex with respect to the columnar lens group. The columnar lens sheet for stereoscopic image display according to (1), which is integrated with a continuous layer that does not exist.

(3) A liquid crystal display device in which the columnar lens sheet for stereoscopic image display according to (1) or (2) is installed on a screen of a liquid crystal panel, and a planar image of the liquid crystal panel is displayed as a stereoscopic image.

(1) According to the columnar lens sheet for stereoscopic image display according to the present invention, the dimensional change with time of the arrangement cycle of the unit columnar lenses can be reduced. Talk can be prevented from occurring over time. In addition, since at least two alignment marks (alignment marks) are provided outside the effective screen area, alignment with respect to pixels of a display panel such as a liquid crystal panel can be easily performed without affecting the screen display.
(2) If the alignment mark is the same material as the columnar lens group and is integrated with a continuous layer without an interface, the alignment mark is formed at the same time as the columnar lens group is formed. There is no error in the positional relationship between the unit columnar lenses constituting the lens and the alignment mark, the alignment mark itself is formed with high accuracy, and alignment can be easily performed in the correct positional relationship.
(3) According to the liquid crystal display device according to the present invention, stereoscopic viewing is performed using a stereoscopic image display columnar lens sheet having the above-described effect as a liquid crystal display device that displays a stereoscopic image from a planar image of a liquid crystal panel. It is possible to prevent the crosstalk of the left and right parallax images from occurring over time due to the dimensional change of the unit columnar lens provided in the columnar lens sheet. In addition, when there is a light shielding pattern such as a light beam control pattern on the glass substrate of the liquid crystal panel, this can be prevented from being visible over time.
In addition, since the columnar lens sheet for stereoscopic image display can be easily aligned with the liquid crystal panel by the alignment mark, the liquid crystal display can effectively utilize the effect of preventing the crosstalk of the left and right parallax images from occurring over time. It becomes a device.

It is a perspective view explaining one Embodiment of the columnar lens sheet for three-dimensional image display by this invention, The whole figure (a) and the vicinity figure (b) of the alignment mark. The perspective view (a) and top view (b) explaining one embodiment paying attention to the unit columnar lens part of the columnar lens sheet for stereoscopic image display by the present invention. The perspective view explaining an example of the optical member for stereoscopic image display using the columnar lens sheet for stereoscopic image display by this invention. The perspective view explaining another example of the alignment mark by this invention. Sectional drawing explaining the convex form and concave form of the alignment mark by this invention. The top view explaining an example of the planar view shape of the alignment mark by this invention. The top view explaining another example of the planar view shape of the alignment mark by this invention. The top view explaining another example (with a guide mark) of the planar view shape of the alignment mark by this invention. The top view which illustrates various shapes of the planar view shape of the alignment mark by this invention, the other party alignment mark, and the external appearance of the mark at the time of aligning these correctly. The top view which illustrates an example (a) of the planar view shape of the alignment mark by this invention, the other party alignment mark (b), and the state (c) at the time of alignment. Sectional drawing explaining one Embodiment of the liquid crystal display device by this invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the drawings are conceptual diagrams, and the scale relationships, aspect ratios, and the like of components may be exaggerated.

[A] Columnar lens sheet for stereoscopic image display:
First, an embodiment of a columnar lens sheet for stereoscopic image display according to the present invention is shown in the perspective views of FIGS. 1 (a) and 1 (b).
In FIG. 1, the plane of the stereoscopic image display columnar lens sheet 10 (the plane parallel to one surface 1p of the base film 1 described later) is parallel to the XY plane. Is the horizontal direction that distributes the left and right parallax images to the left and right of the observer, the Y-axis direction is the vertical direction or the direction orthogonal to the horizontal direction, and the normal direction is Z with respect to the XY plane of the columnar lens sheet 10 for stereoscopic image display As an axial direction.

  In the columnar lens sheet 10 for stereoscopic image display shown in the figure, a large number of unit columnar lenses 2 are arranged on one surface 1p of the base film 1 and the ridgelines 2p are parallel to each other in one direction da (X-axis direction in the drawing). Has been. The arrangement period P of the unit columnar lenses 2 in the one direction da is constant. A plurality of unit columnar lenses 2 arranged periodically constitute a columnar lens group 3. The three-dimensional image display columnar lens sheet 10 includes the columnar lens group 3 and the base film 1.

  In addition, a stretched film such as a biaxially stretched film is used as the base film 1, and the orientation direction of the molecular principal axis of the polymer constituting the base film 1 in the film plane is the ridge line of the unit columnar lens 2. It has a specific relationship with the direction. Specifically, as described in detail later, the inclination angle θ defined as the smaller angle (subordinate angle) of the angles formed by the orientation direction dm of the molecular principal axis and the ridge line direction dp of the unit columnar lens 2. Is set to fall within the range of 0 ° ≦ θ ≦ 50 ° over the entire area of the base film 1.

  Furthermore, in the example of the figure, two alignment marks M are formed outside the effective screen area A of the stereoscopic image display columnar lens sheet 10. The two alignment marks M are examples formed in the rectangular three-dimensional image display columnar lens sheet 10 at positions where the distance between them becomes as large as possible, near the four corners forming the diagonal.

  By setting the tilt angle θ as described above within a specific range and providing the alignment mark M outside the effective screen area A, first, the unit columnar lens 2 over time due to heat or the like. As a result, the crosstalk of the left and right parallax images can be prevented from occurring over time. Second, the alignment mark M makes it possible to easily align the pixel of a display panel such as a liquid crystal panel without affecting the screen display, and can effectively utilize the advantage of small dimensional change. It will be.

Next, FIG. 2 is a perspective view (a) and a plan view (b) illustrating one embodiment focusing on the unit columnar lens 2 portion of the columnar lens sheet 10 for stereoscopic image display. With reference to FIG. 2, the orientation direction dm of the molecular principal axis and the inclination angle θ will be described in more detail.
In FIG. 2, the plane of the columnar lens sheet 10 for stereoscopic image display (a plane parallel to one surface 1p of the base film 1 described later) is parallel to the XY plane, and the X-axis direction is observed in the stereoscopic image display. The horizontal direction in which the left and right parallax images viewed by the person S are distributed to the left and right, and the Y-axis direction is the vertical direction or a direction orthogonal to the horizontal direction, and the direction of the observer S of the stereoscopic image with respect to the stereoscopic image display columnar lens sheet 10 It is assumed in the Z-axis direction.

  In the columnar lens sheet 10 for stereoscopic image display shown in the figure, a large number of unit columnar lenses 2 are arranged on one surface 1p of the base film 1 and the ridgelines 2p are parallel to each other in one direction da (X-axis direction in the drawing). Has been. The arrangement period P of the unit columnar lenses 2 in the one direction da is constant. The arrangement period P is the distance between the ridge lines 2p of the adjacent unit columnar lenses 2. Alternatively, the arrangement period P can also be grasped as the distance between the adjacent valley portions 2v with respect to the valley portions 2v between the adjacent unit columnar lenses 2 (not shown). A plurality of unit columnar lenses 2 arranged periodically constitute a columnar lens group 3. The three-dimensional image display columnar lens sheet 10 includes the columnar lens group 3 and the base film 1.

(Orientation direction dm of molecular principal axis)
A stretched film such as a biaxially stretched film is used as the base film 1, and as a result, the direction of the molecular principal axis of the polymer constituting the base film 1 is oriented rather than disorderly. Yes.
In the present invention, since the base film 1 to be used is a stretched film in the present invention, the orientation of the molecular principal axis is within the film plane, in other words, within the plane parallel to one surface 1p of the base film 1. This is related to the fact that the molecular axis directions of the individual molecules of the polymer constituting the film are not completely random, but are aligned to some extent. For this reason, if the direction of the molecular axis of each molecule, that is, the orientation direction, is averaged as a whole within an area that is sufficiently larger than the molecule and smaller than the pixels of the display panel to be applied, for example, in a 10 μm square area, Direction. The direction obtained by averaging the orientation directions of the molecular axes of the individual molecules as a whole is the orientation direction dm of the molecular principal axis. A double-headed arrow indicated by reference numeral dm in FIG. 2B is the orientation direction of the molecular principal axis.
Note that even if the orientation direction dm of the molecular principal axis is aligned to some extent, normally, the alignment direction dm is not aligned in one direction over the entire surface, and the orientation direction dm of the molecular principal axis is shown in FIG. ) Is distributed as a function dm (X, Y) of position coordinates (X, Y) in the XY plane (a plane parallel to one surface 1p of the base film 1). That is, the orientation direction dm of the molecular principal axis is within a certain range (a range in which the inclination angle θ is 0 ° ≦ θ ≦ 50 °) depending on the location in the plane (parallel to one surface 1p) of the base film 1. Is different.

(Inclination angle θ)
And it is defined as the minor angle of the smaller one of the angles formed by the orientation direction dm of the molecular principal axis and the ridge line direction dp (Y-axis direction in the drawing) which is the direction in which the ridge line 2p of the unit columnar lens 2 extends. The tilt angle θ is also distributed as a function θ (X, Y) of position coordinates (X, Y) in the XY plane (a plane parallel to one surface 1p of the base film 1). Is set to fall within the range of 0 ° ≦ θ ≦ 50 °.

Incidentally, it is preferable that the base film 1 has at least a region where the inclination angle θ is 0 °.
The region where the inclination angle θ is 0 ° is ideally the entire region of the base film 1. Therefore, a film in which the orientation direction dm of the molecular principal axis is extremely uniform, such as a polarizing plate film, may be used as the base film. However, such a film is not practical in that it requires advanced manufacturing techniques and is extremely expensive. Therefore, in-plane distribution of the alignment direction dm due to the presence of a certain degree of non-uniformity in the alignment direction dm (X, Y) is allowed, and at least a region where the inclination angle θ is 0 ° is partially set. It is good to have it even in.

Further, the portion where the inclination angle θ is 0 ° is effective near the center in the unit columnar lens arrangement direction. Therefore, in the portion where the inclination angle θ is 0 °, the dimension between both ends in the arrangement direction da of the unit columnar lenses 2 of the base film 1 is a distance L, and the width of both ends of the base film is It is preferable to use the base film 1 in a region in the vicinity of the center where the distance measured from one end is (L / 2) ± (L / 4).
When the base film 1 does not include a region where the tilt angle θ is 0 °, the value of the tilt angle θ is in the distribution range of the tilt angle θ in the vicinity of the center of the base film 1. The average value or a value close to it should be set.

  As described above, by setting the in-plane distribution of the inclination angle θ, the dimensional change (contraction) in the arrangement direction da of the unit columnar lenses 2 of the stereoscopic image display columnar lens sheet 10 over time is minimized. It is possible and preferable.

(Application to stereoscopic image display optical members)
The columnar lens sheet 10 for stereoscopic image display has other optical elements on the surface on which the columnar lens group 3 is not formed, the surface on which the columnar lens group 3 is formed, or both surfaces. Can be stacked.
For example, the columnar lens sheet 10 for stereoscopic image display may be used as the optical member 20 for stereoscopic image display exemplified in FIG. 3 by closely laminating the glass substrate 5 on the side where the columnar lens group 3 is not formed. it can.
The stereoscopic image display optical member 20 of FIG. 3 further has one surface 1p having a columnar lens group 3 composed of a large number of unit columnar lenses 2 with respect to the stereoscopic image display columnar lens sheet 10 illustrated in FIG. Is a plate-like glass substrate 5 laminated on the opposite surface, that is, the other surface 1q of the base film 1 with an adhesive layer 4 interposed therebetween.

  The stereoscopic image display optical member 20 in FIG. 3 has the light beam control pattern 6 on the lower surface of the glass substrate 5 opposite to the surface in contact with the pressure-sensitive adhesive layer 4. The light beam control pattern 6 has a period corresponding to (associated with) the arrangement period P of the unit columnar lenses 2 in one direction da (X-axis direction) that is the arrangement direction of the unit columnar lenses 2. For example, in the case of a color liquid crystal panel, the light ray control pattern 6 corresponds to a light blocking pattern of a black matrix in a color filter formed on the front glass substrate. Further, the light ray control pattern 6 as the light shielding pattern shows an image adjacent to the left and right parallax images displayed on the image display element when the viewpoint position of the observer S is slightly shifted in the left and right direction (X-axis direction in the drawing). In other words, it also has a function of making it difficult for crosstalk between right and left parallax images to occur.

  Note that in the case of a stereoscopic image display apparatus in which only the front side is an observable range for stereoscopic viewing, that is, in the case of two-lens display, in the lenticular method, one arrangement period P of unit columnar lenses 2 (in other words, one unit columnar lens 2) Corresponding to the above, two images of the left-eye image and the right-eye image are sufficient for the parallax image of the two-dimensional image displayed by the image display element. For this reason, in the case of binocular display, if the two images are alternately displayed in the direction of the arrangement period P, stereoscopic viewing is possible. Therefore, when a light-shielding pattern is provided between the left and right parallax images as the light beam control pattern 6, the period of the light-shielding pattern in the one direction da is a period in which the fineness of the arrangement period P of the unit columnar lenses 2 is twice. .

  With the configuration as described above, the columnar lens sheet for stereoscopic image display 10 used has an inclination angle θ formed by the ridge line direction dp of the unit columnar lens 2 and the molecular principal axis dm of the base film 1, and heat In the presence of the above, the dimensional change in the arrangement direction da of the unit columnar lenses 2 over time is minimized, and dimensional stability that prevents crosstalk of the left and right parallax images from occurring over time is obtained. When the light beam control pattern 6 is a light shielding pattern, it can be prevented from appearing with time in the presence of heat. As a result, it is possible to prevent a decrease in luminance due to the appearance of the light shielding pattern.

As an application example of the stereoscopic image display columnar lens sheet 10, in the stereoscopic image display optical member 20 illustrated in FIG. 3, the stereoscopic image display columnar lens sheet 10 has a lens surface on the columnar lens group 3 side. It arrange | positioned toward the observer S side. However, although not illustrated, conversely, the base film 1 side, that is, the other surface 1q side can be arranged toward the observer S side.
In addition, the stereoscopic image display columnar lens sheet 10 may be disposed between the light source and the display panel on the light source side on the back surface of the display panel. In this case, the orientation of the lens surface of the columnar lens group 3 can be either on the display panel side (observer S side) or on the light source side.

  Hereinafter, each component of the columnar lens sheet for stereoscopic image display will be further described.

[Base film]
The base film 1 is a transparent stretched film such as a polyester resin such as polyethylene terephthalate or polyethylene naphthalate, an acrylic resin such as polymethyl methacrylate, a polycarbonate resin, a polyolefin resin such as polypropylene, a polyamide resin, or the like. A transparent resin film is mentioned. Among them, polyethylene terephthalate, which is a kind of polyester resin, is representative, and the biaxially stretched film is a suitable base film in terms of cost, transparency, mechanical strength, and the like. However, since molecular orientation is caused by stretching, by defining the tilt angle θ with respect to the orientation direction dm of the molecular principal axis as in the present invention, it can be used while preventing crosstalk over time.
In addition, although the base film 1 is "film shape", a "film" includes the concept of "sheet" and "plate" here, and these terms are based only on the difference in a name. , Are not distinguished from each other. That is, they are not distinguished by thickness or rigidity. For example, the thickness of the base film 1 is 50 μm to 5 mm or the like.

In general, the size and shape of the base film 1 in plan view (XY plane) are equal to the size and shape of the columnar lens sheet 10 for stereoscopic image display.
When the stereoscopic image display columnar lens sheet 10 is laminated with the glass substrate 5 like the stereoscopic image display optical member 20 described with reference to FIG. 3, the size and shape of the base film 1 are made of glass. It is equal to or smaller than the size and shape of the substrate 5.

(Unit columnar lens)
The unit columnar lens 2 is a columnar lens whose main cut surface has a shape such as a circle, an ellipse, a fence line, a hyperbola, a sine (wave) curve, a hyperbolic sine curve, an elliptic function curve, or a part of a cycloid curve. Typically, it is a so-called bowl-shaped lens. The unit columnar lens 2 having a bowl-shaped cross section is typically a lenticular lens. Note that the dimensions of the unit columnar lens 2 are combined with the columnar lens sheet 10 for stereoscopic image display, and the fineness of pixels of the image display element that displays a two-dimensional image, the arrangement period of the light beam control pattern 6, and stereoscopic viewing are enabled. The distance is determined according to the set distance of the observable range, the refractive index of the constituent material, and the stereoscopic method such as a two-lens method or a multi-view method.

  In addition, the “main cut surface” refers to the arrangement direction da of the unit columnar lenses 2 in a cross section parallel to the normal line n (see FIG. 2A) standing on one surface 1p of the base film 1. A parallel section. In other words, the cross section is parallel to the normal line n and perpendicular to the ridge line direction dp of the unit columnar lens 2. In FIG. 2A, the Z axis is parallel to the normal line n.

The unit columnar lens 2 is not made of an inorganic material such as glass but is made of a resin because it is inexpensive and easy to manufacture. If the unit columnar lens 2 is made of an inorganic material such as glass, crosstalk of the left and right parallax images due to dimensional changes does not occur.
The resin constituting the unit columnar lens 2 is basically not particularly limited. Examples thereof include thermoplastic resins such as acrylic resins and polycarbonate resins, and ionizing radiation curable resins such as acrylate-based and epoxy-based resins that are cured by ultraviolet rays or electron beams.
In the case of a thermoplastic resin, for example, the unit columnar lens 2 can be formed on one surface 1p of the base film 1 by a thermoforming method such as a melt extrusion method, an injection molding method, or an embossing method by hot pressing. In the case of an ionizing radiation curable resin, for example, the unit columnar lens 2 is brought into contact with one surface 1p of the base film 1 with an uncured ionizing radiation curable resin liquid, and the resin liquid is used as a mold. It can be formed by a molding method in which the resin is crosslinked and cured by irradiation with ionizing radiation while being sandwiched between the base film 1. In addition, when using ionizing radiation curable resin for a resin liquid and making it harden | cure with ionizing radiation, it is called what is called 2P method (photopolymer method).
In particular, the 2P method is capable of rapidly curing the ionizing radiation curable resin and is excellent in productivity, and above all, in that the shape of the unit columnar lens 2 that directly affects the stereoscopic image quality can be formed with high accuracy. It is superior to a thermoforming method using a thermoplastic resin, and is preferable for stereoscopic viewing that requires high accuracy.

  In the valley 2v between the unit columnar lenses 2 arranged on the base film 1, even if one surface 1p of the base film 1 is exposed, as shown in FIG. The one surface 1p may be covered with a resin constituting the unit columnar lens 2.

[Inclination angle θ]
The inclination angle θ is an angle related to the orientation direction dm of the molecular principal axis of the polymer constituting the base film 1. In the present invention, since the base film 1 to be used is a stretched film, the polymer constituting the film in the film plane, in other words, in the plane parallel to the one face 1p of the base film 1 is used. This is related to the fact that the molecular axis directions of the individual molecules are not completely random but are aligned to some extent. For this reason, if the direction of the molecular axis of each molecule, that is, the orientation direction, is averaged as a whole within an area sufficiently larger than the molecule and smaller than the pixel, for example, in a 10 μm square area, a certain directionality is exhibited. . The direction obtained by averaging the orientation directions of the molecular axes of the individual molecules as a whole is the orientation direction dm of the molecular principal axis.
Then, as shown in FIG. 2B, the orientation of the molecular principal axis in the orientation direction dm is defined as an angle with the ridge line direction dp in which the ridge line 2p of the unit columnar lens 2 extends. That is, the orientation direction dm of the molecular principal axis and the unit columnar lens 2 at each point (X, Y) in a plane parallel to one surface 1p of the base film 1 (XY plane in the figure). The smaller one of the angles formed by the ridge line direction dp, that is, the inferior angle, is defined as the inclination angle θ (the function θ (X, Y) of the point (X, Y)).

  In the present invention, it is preferable that the base film 1 has at least a region where the inclination angle θ is 0 °.

  The region where the inclination angle θ is 0 ° is ideally the entire region of the base film 1. Therefore, a film in which the orientation direction dm of the molecular principal axis is extremely uniform, such as a polarizing plate film, may be used as the base film. However, such a film is not practical in that it requires advanced manufacturing techniques and is extremely expensive. Therefore, the in-plane distribution of the alignment direction dm due to the presence of a certain degree of non-uniformity in the alignment direction dm is allowed, so that at least the region having the inclination angle θ of 0 ° is provided.

By the way, although biaxially stretched polyethylene terephthalate film is a kind of typical stretched film as various films such as base film 1, the orientation direction dm of the molecular principal axis is generally different in the state of the belt-like film, particularly in the width direction. Is normal. In general, the alignment direction dm is inclined toward both ends with respect to the alignment direction dm at the center in the width direction.
For this reason, it is preferable to use an in-plane distribution based on the non-uniformity of the orientation direction dm of the corresponding molecular principal axis by using a general-purpose and cost-effective film as much as possible. It will be.
Therefore, in the present invention, it is more preferable that the inclination angle θ is 50 ° or less, more preferably 45 ° or less in the entire region of the base film 1 even if the region has a region where the inclination angle θ is not 0 °. That is, the inclination angle θ is preferably 0 ° ≦ θ ≦ 50 °, and more preferably 0 ° ≦ θ ≦ 45 °.
In addition, it is effective to make the region where the inclination angle θ is 0 ° as close to the center as possible. Here, the vicinity of the center, as shown in FIG. 2 (b), is a distance L between both ends in the arrangement direction da of the unit columnar lenses 2 of the base film 1, of the width direction both ends of the base film 1. This is a region where the distance measured from one end satisfies (L / 2) ± (L / 4).

By making the inclination angle θ as described above, the dimensional change in the arrangement direction da of the unit columnar lenses 2 can be more reliably minimized, so that the crosstalk of the left and right parallax images and the light control pattern 6 of the laminated glass substrate can be obtained. In the case of the light shielding pattern, it can be surely prevented that the light shielding pattern becomes visible with time.
As described above, when the inclination angle θ between the orientation direction dm of the molecular principal axis and the ridge line direction dp of the unit columnar lens 2 is defined, how this influences the stability of the dimensional change of the unit columnar lens 2 positively. Is currently unknown, but anyway, it has been found that the dimensional change can be reduced.

[Alignment mark]
The alignment mark M is a mark (alignment mark) used for aligning the stereoscopic image display columnar lens sheet 10 in a correct positional relationship with another optical member such as a display panel. In the present invention, this alignment mark M is not on the other surface 1q of the transparent substrate 1, but on the surface of the unit columnar lens 2, in other words, on the surface of the columnar lens group 3 composed of a large number of unit columnar lenses 2. It is provided. By providing the alignment mark M not on the other surface 1q of the transparent substrate 1 but on the surface of the columnar lens group 3, the relative positional relationship with the unit columnar lenses 2 constituting the columnar lens group 3 is more accurate. Can be formed.

[Plane position]
At least two alignment marks M are provided outside the effective screen area A of the columnar lens sheet 10 for stereoscopic image display. The effective screen area A is an area used for displaying an image on the display panel when the stereoscopic image display columnar lens sheet 10 is applied to a display panel such as a liquid crystal panel.

  The position where the alignment mark M is provided is not particularly limited as long as it is outside the effective screen area A. Even when only two alignment marks M are provided, for example, in FIG. 1A, two alignment marks M are arranged in such a manner that both the XY coordinates are different from each other as illustrated. The alignment mark M may be a position where the Y-axis coordinates are the same and only the X coordinate is changed, or two alignment marks M may be the positions where the X-axis coordinates are the same and only the Y coordinates are changed.

  However, for alignment, the horizontal position and the vertical position are aligned with other optical members such as a display panel in a correct positional relationship. It is also necessary to adjust the rotation (twist) of the columnar lens sheet 10 for stereoscopic image display to zero. For this reason, in the case where the minimum two are provided, it is preferable that the two are provided as far as possible from each other because the rotation angle can be easily detected. In the example of FIG. 1A, by providing two in the vicinity of diagonal corner portions, the distance can be maximized or maximized as much as possible with respect to the rectangular three-dimensional image display columnar lens sheet 10. It is also an example where the positions are separated.

  In the case of providing the minimum two, the columnar lens sheet 10 for stereoscopic image display requires alignment accuracy in the arrangement direction da of the unit columnar lenses 2 as compared to the ridge line direction dp of the unit columnar lenses 2. Therefore, it is preferable that the two are separated from each other in the arrangement direction da as much as possible from the viewpoint of improving the alignment accuracy in the arrangement direction da. In the example of FIG. 1A, the maximum distance is provided in the X-axis direction parallel to the arrangement direction da with respect to the rectangular three-dimensional image display columnar lens sheet 10 by being provided in the vicinity of the diagonal corners. It is also an example where the positions are separated.

The alignment mark M may be provided so that one alignment mark M fits on the surface of one unit columnar lens 2, or may be provided so as to straddle two adjacent unit columnar lenses 2. You may provide so that the 3 or more unit columnar lens 2 connected may be straddled.
The position where the alignment mark M is provided does not have to be a plane without providing the unit columnar lens 2 exclusively.

  When three or more alignment marks M are provided, at least two of the alignment marks M are preferably set in consideration of the above. The positions of the remaining alignment marks M are arbitrary.

[shape]
The shape of the alignment mark M is not particularly limited. For example, the alignment mark M illustrated in FIG. 1B has a “cross” shape in plan view and straddles two adjacent unit columnar lenses 2 so as to straddle the adjacent unit columnar lenses 2. In this example, 2v is provided as the mark center point in the X-axis direction (arrangement direction da).
By using such a cross shape, alignment in the arrangement direction da and the ridge line direction dp perpendicular thereto can be easily performed.
Further, the alignment mark M may be configured such that one alignment mark M is formed from a plurality of small pieces at one place. For example, the alignment mark M in FIG. 4 is an example in which one alignment mark M is provided so as to straddle two adjacent unit columnar lenses 2 as in FIG. 1B. M is also an example composed of a plurality of small pieces Ms. The small piece Ms has a straight line shape in plan view extending in the ridge line direction dp. In this example, a plurality of small pieces Ms are arranged at equal intervals and arranged in the arrangement direction da, and one alignment mark M is formed at one place.
In this way, alignment in the arrangement direction da, which requires particularly high accuracy, is facilitated because it is multiplexed by the plurality of small pieces Ms.

(Cross-sectional shape: uneven surface)
As shown in the cross-sectional view of FIG. 5, the surface of the portion of the single alignment mark M may be convex with respect to the surface of the other portion {FIG. Or {FIG. 5 (b)}, which may have both a convex shape and a concave shape (not shown), or the same level surface. Both FIG. 1B and FIG. 2B are examples of convex shapes.
The convex alignment mark M is formed by forming a concave groove having a concave / convex shape opposite to the unit columnar lens 2 by cutting with a cutting tool or the like because the molding surface has a concave shape in the mold when molding the convex alignment mark M. Therefore, by additionally cutting only the portion of the alignment mark M, there is an advantage that a mold that can simultaneously form the columnar lens group 3 including the alignment mark M and the unit columnar lens 2 can be easily manufactured.
On the contrary, the concave alignment mark M can be created by projecting a portion corresponding to the alignment mark M from the mold surface for the lens shape when forming the mold surface. The concave alignment mark M is further filled with colored ink inside the concave shape so that the level mark is the same as that of the alignment mark M and the surrounding area, and the alignment mark is colored or opaque. Mark M can also be used.

  In the case of a convex shape, a shape having a flat surface on the top surface of the convex portion may be used as shown in FIGS. Since the alignment mark M having a flat upper surface is formed on the surface of the columnar lens group 3, even when the alignment mark M is colorless and transparent, the columnar shape for stereoscopic image display is displayed. The path of the light beam that vertically passes through the lens sheet 10 goes straight in the alignment mark M portion, and in the other portion, it is refracted by the lens of the columnar lens group 3 and does not go straight. As a result, if the transmitted light is measured mainly using the vertically traveling light, the alignment mark M portion becomes bright and the other portions become dark, so that there is an advantage that the alignment mark M can be detected as a change in the density of the transmitted light. .

In the case of the convex alignment mark M, in the example of FIGS. 1B and 4, the alignment mark M is of course convex with respect to the valley of the unit columnar lens 2, but the unit columnar lens It was an example of a convex shape with respect to 2 ridge lines.
However, although not shown, the alignment mark M is not convex or concave with respect to the ridge line portion of the unit columnar lens 2 and may have a shape having the same height (Z-axis coordinate) as the ridge line portion. If it does in this way, the thickness increase in the alignment mark M part of the columnar lens sheet 10 for stereoscopic image display by the convex shape from a ridgeline part, and the wear accompanying it can be prevented.

(Planar shape and its dimensions)
Here, FIG. 6 to FIG. 8 are planar view shapes and dimension examples of the alignment mark M. FIG. Note that the alignment mark M in each drawing including FIGS. 6 to 8 does not indicate whether the alignment mark M is colorless, transparent, colored, or opaque.
The alignment mark M in FIG. 6 is the alignment mark M illustrated in FIG. 1B, and is an example of a cross shape in which straight lines having a thickness of 0.1 mm and a length of 0.3 mm intersect in a cross shape. is there.
The alignment mark M in FIG. 7 is an example of a T shape in which a straight line with a thickness of 0.1 mm and a length of 0.3 mm intersects a straight line with a thickness of 0.1 mm and a length of 0.5 mm in a T shape. It is.

The alignment mark M in FIG. 8 is formed by arranging a plurality of isosceles triangular small pieces Ms having a base of 0.01 mm and a height of 0.1 mm, with the bases aligned in a straight line and with the apexes on the same side without gaps. It is an example of a configured alignment mark M. The left-pointing arrow on the right side of the drawing is not the alignment mark M but a guide mark Mg for guiding the position where the alignment mark M exists. This guide mark Mg itself is not used for alignment. The guide mark Mg is a guide mark for finding the alignment mark M earlier in alignment with the naked eye or machine operation. Note that one guide mark Mg may be provided for one alignment mark M, but a plurality of guide marks Mg may be provided. The distance between the alignment mark M and the guide mark Mg is about the size of the alignment mark M in the figure, but is not limited to this. The guide mark Mg can be formed of the material described for the alignment mark M. The guide mark Mg is preferably formed of the same material as the alignment mark M at the same time as the alignment mark M in terms of easy formation.
Further, when the alignment mark M is a plurality of small pieces Ms, as shown in FIG. 4, a plurality of straight lines having a constant thickness are not arranged as the small pieces Ms, but a shape such as an isosceles triangle that gradually decreases or gradually increases in thickness. By arranging a large number, it is possible to make the alignment state easy to understand by the overlapping shape due to the interaction with the alignment mark of the counterpart.

(Alignment mark M2 of the other party paired with the alignment mark M)
Together with the alignment mark M of the stereoscopic image display columnar lens sheet 10, other optical members that are the alignment target of the stereoscopic image display columnar lens sheet 10 also have a counterpart alignment mark that forms a pair with the alignment mark M. It is preferable to provide M2. The counterpart alignment mark M2 is provided outside the effective screen area at a position corresponding to an optical member, for example, a transparent electrode pattern on a glass substrate, a light beam control pattern, a black matrix of a color filter, and the like. preferable.
At this time, when the alignment mark M of the columnar lens sheet 10 for stereoscopic image display and the alignment mark M2 of the other party are in the correct positional relationship, it is preferable to make the shapes easy to distinguish from each other. is there.

  FIG. 9 illustrates some of various other shape examples of the alignment mark M in plan view. In addition, in the same figure, the alignment mark M2 of the other party paired with this is also illustrated. The upper row is the alignment mark M, the interruption is the counterpart alignment mark M2, and the lower row shows the alignment shape M + M2 when they are correctly aligned and overlapped. In FIG. 9, (a) a set of crosses and squares, (b) a set of crosses and crosses, (c) a set of crosses and white cross-inclusive squares, and (d) a small square and small white outlines. (E) is a set of 2 quadrants and 2 inverted quadrants, (f) is a set of isosceles triangles and upside down isosceles triangles, (g) is a straight line and a vertical A set of straight lines, (h), is a set of U-shaped and inverted U-shaped.

  Various ideas for making the alignment easier can be taken by the interaction between the alignment mark M and the alignment mark M2 of the other party. The alignment mark M in FIG. 9 is also an example. FIG. 10 illustrates the alignment mark M of (a) and the alignment mark M2 of the other party of (b). The alignment mark M and the alignment mark M2 are examples in which the arrangement pitches of the small pieces Ms are not the same but different from each other. By changing the arrangement pitch, interference fringes are generated when they are overlapped as shown in FIG. 10C, and the alignment state can be determined by the pattern of the interference fringes.

[material]
The material constituting the alignment mark M is basically not particularly limited. The alignment mark M may be the same material as the columnar lens group 3 or a different material. The alignment mark M may be any of colorless and transparent, colored and transparent, and opaque. If it is opaque, it may be formed of a metal thin film or colored ink. In addition, the colored transparent may be formed with a colored transparent ink.

However, the alignment mark M is made of the same material as that of the columnar lens group 3, and the alignment mark M and the columnar lens group 3 are longitudinal planes {in FIG. 1B, a plane parallel to the Z axis, In the XZ plane, the YZ plane, etc., a form in which the layers are integrated with a continuous layer having no interface is preferable.
In terms of the manufacturing method, this form means the alignment mark M and the columnar lens group 3 obtained by simultaneously forming the alignment mark M and the columnar lens group 3 together with the same mold. The point is that the columnar lens group 3 is formed first and then the alignment mark M is not additionally formed on the surface of the columnar lens group 3. By simultaneously forming the alignment mark M and the columnar lens group 3 from the same mold, the position of the alignment mark M with respect to the unit columnar lens 2 of the columnar lens group 3 can be stably formed with high accuracy. become. If the alignment mark M is formed after the columnar lens group 3 is formed, it is not easy to stably and highly accurately form the position of the alignment mark M with respect to the unit columnar lens 2 of the columnar lens group 3. .

  A feature of the columnar lens group 3 and the alignment mark M formed by simultaneous molding is that the alignment mark M is a portion where the alignment mark M is convex with respect to the columnar lens group 3. And the columnar lens group 3 are integrated in a continuous layer having no interface. Here, referring back to the cross-sectional view of FIG. 5, in the case of the convex alignment mark M in FIG. 5A, the portion indicated by the broken line of the horizontal line is the alignment mark M and the columnar lens group. 3 is a virtual boundary Bd. When the portion above the boundary Bd in the drawing is regarded as the region of the alignment mark M, and the portion below the boundary Bd as the region of the columnar lens group 3, both regions are composed of the same material. Moreover, the boundary Bd is only a virtual one, and no clear interface is observed. Therefore, the region of the alignment mark M and the region of the columnar lens group 3 are integrated in a continuous layer that is continuous at the virtual boundary Bd. Such a form in which the interface is made of the same material and there is no interface is not possible except that the alignment mark M and the columnar lens group 3 are formed of the same material by simultaneous molding.

  On the other hand, in the form in which the alignment mark M is concave as shown in FIG. 5B, the virtual boundary Bd itself does not exist. However, in the case of forming by simultaneous molding, the concave shape requires higher technology than the convex shape by producing the mold surface.

  In this way, if the alignment mark M is a convex portion of the columnar lens group 3 and is integrated with a continuous layer having the same material and no interface as the columnar lens group 3, the columnar lens group 3 is formed. Since the alignment mark M is formed at the same time, the positional relationship error between the unit columnar lens 2 constituting the columnar lens group 3 and the alignment mark M can be made zero. As a result, the alignment mark M itself is formed with high accuracy, and alignment can be easily performed using the alignment mark M with high accuracy.

  Hereinafter, additional components of the stereoscopic image display columnar optical member 20 to which the stereoscopic image display columnar lens sheet 10 is applied will be further described.

(Adhesive layer)
For the pressure-sensitive adhesive layer 4, a transparent pressure-sensitive adhesive is used, and a known material such as an optical application may be appropriately employed. Moreover, a releasable adhesive is preferable in that it can be peeled off when the stereoscopic image display columnar lens sheet 10 and the glass substrate 5 fail to be bonded. Examples of the adhesive that can be used for such an adhesive layer include acrylic adhesives, silicone adhesives, polyester adhesives, rubber adhesives, and the like.

[Glass substrate]
As the glass substrate 5, a transparent flat glass plate is used, and a known one such as an optical application may be appropriately employed. Note that the glass substrate 5 may or may not be used as a glass substrate (for example, a front glass substrate) of an image display element that displays a planar image from which a stereoscopic image is based.

(Light control pattern)
The light beam control pattern 6 is a pattern for performing an operation such as blocking a light beam that attempts to pass through the columnar lens sheet for stereoscopic image display 10 when displaying a stereoscopic image, and the pattern is not random but periodic. It is a pattern which has. Moreover, the periodicity is a pattern having periodicity in the arrangement direction da of the unit columnar lenses 2 and having periodicity corresponding to the arrangement period P of the unit columnar lenses 2. The periodicity is in the arrangement direction da (X-axis direction in FIG. 1). Therefore, in the ridge line direction dp of the unit columnar lens 2, the light ray control pattern 6 is not limited to a pattern having a pattern parallel to the ridge line direction dp, and a pattern that is oblique or broken with the ridge line direction dp. Do not exclude. Further, for example, in the case of a black matrix corresponding to display pixels such as color pixels of a liquid crystal panel, a lattice shape is formed.
In addition to the side opposite to the stereoscopic image display columnar lens sheet 10 of the glass substrate 5 as shown in FIG. 3, the light beam control pattern 6 is formed on the side of the image observer of the columnar lens sheet 10 for stereoscopic image display. Also, it may be between the columnar lens sheet 10 for stereoscopic image display and the glass substrate 5. Such a light beam control pattern 6 is usually formed on a certain substrate (support). The substrate is a glass substrate 5 as shown in FIG. It can also be formed on the substrate.

The light beam control pattern 6 is a pattern for performing light beam control such that one or more of the transmittance, reflectance, traveling direction, polarization state, phase (difference), etc. of visible light necessary for stereoscopic viewing is changed. . Such a light beam controlled portion is formed on the glass substrate 5 in a pattern by the light beam control pattern 6. For example, it is a light shielding pattern that blocks transmitted light by suppressing the transmittance. In the embodiment illustrated in FIG. 3, the light beam control pattern 6 is an example formed on one side of the lower surface of the glass substrate 5, but the formation surface is not limited to this, and the drawing of the glass substrate 5. It may be an upper surface or both upper and lower surfaces.
Note that the periodicity corresponding to the arrangement period P of the unit columnar lenses 2 included in the light beam control pattern 6 means that a pixel displaying a planar image of the image display element is stereoscopically viewed as a stereoscopic image by the stereoscopic image display columnar lens sheet 10. The periodicity is a predetermined positional relationship associated with the positions of the unit columnar lenses 2 arranged in the arrangement period P, as provided for.

  For example, when applied to a stereoscopic image display device in which only the central direction of the front surface in the Z-axis direction is set as an observable range for stereoscopic viewing, that is, in the case of binocular display, the lenticular method corresponds to the arrangement period P of the unit columnar lenses 2. Thus, the image display element alternately displays the pixels of the left-eye image and the right-eye image in the direction of the arrangement period P. At this time, if a light-shielding pattern is provided between the pixel of the adjacent left-eye image and the pixel of the right-eye image, immediately from the adjacent pixel when the viewpoint is shifted in the horizontal direction (arrangement direction da). Since light rays can be prevented from entering the observer's eyes, crosstalk between the left-eye image and the right-eye image can be prevented. At this time, the periodicity of the light beam control pattern 6 as the light shielding pattern corresponds to the periodicity corresponding to the two light beam control patterns 6 because the two right and left parallax images correspond to one unit columnar lens 2. .

  Further, in the above case, when an image display element that performs color display by configuring one left-eye or right-eye pixel with, for example, red, green, and blue sub-pixels, the sub-pixel is a unit columnar lens. When they are arranged at equal intervals in the direction of the two arrangement directions da (X-axis direction in FIG. 3), a black matrix that partitions these sub-pixels can be a light shielding pattern. The light beam control pattern as the light shielding pattern at this time is finer. However, when the sub-pixels of three colors of red, green, and blue are arranged in a direction orthogonal to the arrangement direction da of the unit columnar lenses 2 (Y-axis direction in FIG. 1), the same as described above.

[Others]
The stereoscopic image display optical member 20 may include other elements other than the above-described components. For example, a polarizing plate may be included as in the case where a liquid crystal display device capable of displaying a stereoscopic image is applied to a liquid crystal panel described later.

[Measurement of crosstalk]
Note that the crosstalk between the left and right parallax images may be performed visually, but can be measured, for example, by displaying white in the left eye image and displaying black in the right eye image. In this case, normally, it appears only white at the left eye observation position and black at the right eye observation position, but when crosstalk occurs, white is mixed with black at the left eye observation position, and black is white at the right eye observation position. Is mixed. By measuring this with an optical device such as a camera, it can be digitized.

[Use]
The use of the columnar lens sheet 10 for stereoscopic image display according to the present invention can be used for a stereoscopic image display device that displays an autostereoscopic image by being used together with an image display element that displays a planar image from which a stereoscopic image is based. . The image display element that displays a flat image is not particularly limited, and various known image display elements that perform flat image display such as a liquid crystal panel can be combined.
In the above description, the columnar lens sheet for stereoscopic image display 10 is arranged in front of the image display element, so that the left and right parallax images from the image display element are distributed to the left and right eyes of the observer, so-called lenticular type stereoscopic image. It explained on the assumption of the display. However, the columnar lens sheet 10 for stereoscopic image display is not particularly limited as long as it is used as a stereoscopic image display optical member for stereoscopic image display, more preferably for stereoscopic image display that can make use of its dimensional stability over time. . In this sense, the columnar lens sheet 10 for stereoscopic image display according to the present invention has a main cut surface shape in addition to a columnar lens whose unit columnar lens 2 is composed of only a curved surface, such as a lenticular lens. For example, even in the case of a columnar prism including a straight line such as a triangle, the effect of dimensional stability can be obtained.

[B] Liquid crystal display device:
The liquid crystal display device according to the present invention is a stereoscopic image display device that includes at least a liquid crystal panel and the above-described stereoscopic image display columnar lens sheet 10 and can be viewed stereoscopically. In addition, a light source that normally allows the image of the liquid crystal panel to be visually recognized is provided. The sectional view of FIG. 11 is a diagram conceptually showing an embodiment of the liquid crystal display device 30. The liquid crystal display device 30 shown in the figure includes a liquid crystal panel 32 on a light exit surface of a light source 31 as a back light source, and includes the above-described three-dimensional image display optical member 20 on the front surface of the liquid crystal panel 32. The stereoscopic image display optical member 20 includes the above-described stereoscopic image display columnar lens sheet 10.
The liquid crystal panel 32 has a liquid crystal layer 32c between a front glass substrate 32a and a rear glass substrate 32b. In the figure, illustration of a transparent electrode formed on the inner surfaces of the glass substrates 32a and 32b, a polarizing plate laminated on the substrate surface, and the like is omitted. Further, when displaying a color image, a color filter (not shown) is also formed on the inner surface of the front glass substrate 32a, and the color filter is a black matrix that becomes a light ray control pattern 6 between each of red, green, and blue colors, for example. Have The light source 31, the liquid crystal panel 32, and the constituent elements other than those described above may appropriately employ conventionally known liquid crystal panels or constituent members for stereoscopic viewing.

  Further, in the liquid crystal display device 30 of the figure, the glass in the stereoscopic image display optical member 20 as illustrated in FIG. 3 provided with the columnar lens sheet 10 for stereoscopic image display as illustrated in FIG. The substrate 5 is also a front glass substrate 32 a that is a component of the liquid crystal panel 32. The light beam control pattern 6 formed on the glass substrate 5 is a black matrix (not shown) which is a light shielding pattern formed on the inner surface of the front glass substrate 32a. Further, the unit columnar lenses 2 in the stereoscopic image display columnar lens sheet 10 provided in the stereoscopic image display optical member 20 are arranged in the X-axis direction. The X-axis direction corresponds to the left-right direction for the observer S of the image.

The left and right parallax images as flat images displayed by the pixels of the liquid crystal layer 32c of the liquid crystal panel 32 are observed by the observer S located in the observable range in front of the liquid crystal display device 30 by the stereoscopic image display columnar lens sheet 10. However, it can be stereoscopically viewed as a stereoscopic image.
In the present embodiment, the liquid crystal panel 32 has polarizing plates (not shown) on the front and rear surfaces thereof, and a polarizing plate is laminated on the front surface of the front glass substrate 32a. The polarizing plate is provided between the pressure-sensitive adhesive layer 4 laminated on the columnar lens sheet 10 for image display and the glass substrate 5.

In such a liquid crystal display device 30, a stereoscopic image display optical system that employs a stereoscopic image display columnar lens sheet 10 with little dimensional change over time of the arrangement period P of the unit columnar lenses 2 as described above. Since the member 20 is used, it is possible to prevent the occurrence of a phenomenon in which luminance decreases with time due to crosstalk in which right and left parallax images are mixed with a stereoscopic image and a light-shielding pattern that is a light ray control pattern. . For this reason, it is possible to prevent the deterioration of the stereoscopic image quality over time.
In the present embodiment, the light beam control pattern is an example of a black matrix as a light shielding pattern, but the light beam control pattern is not limited to this.

[Use]
The application of the liquid crystal display device 30 according to the present invention is not particularly limited as long as it is an application for displaying a stereoscopic image. For example, a stereoscopic display and a stereoscopic television. The three-dimensional display is a mobile phone, a portable information terminal, a portable or fixed game machine, a display unit of a personal computer, an electronic signboard, a digital photo frame, a medical display, and the like.

  Hereinafter, the present invention will be further described with reference to examples and comparative examples.

[Example 1]
As shown in FIG. 1 and FIG. 2A, a large number of bowl-shaped lenticular lenses are periodically arranged as the unit columnar lens 2, and the unit columnar lens 2 in the vicinity of the corner that forms a diagonal outside the effective screen area A is shown. A three-dimensional image display columnar lens sheet 10 having two alignment marks M on the surface was produced.

  First, a columnar lens group 3 made up of a large number of unit columnar lenses 2 as a mold is a mold surface of a columnar lens pattern having a reverse concave / convex shape, and has a reverse concave / convex shape from an alignment mark M as shown in FIG. A metal cylinder-shaped (cylindrical) mold having a mold surface near the corner was prepared. Then, a transparent acrylic UV curable resin liquid is applied to this mold, and a transparent biaxially stretched polyethylene terephthalate film (PET film) having a thickness of 125 μm is further laminated thereon by UV irradiation. The resin liquid was cured. Then, the columnar lens sheet 10 for stereoscopic image display in which the unit columnar lenses 2 were arranged on one surface 1p of the base film 1 in parallel with the ridge lines thereof was produced.

At this time, the orientation direction dm of the molecular principal axis of the base film 1 is transmitted light when the base film 1 is rotated between two polarizing plates in a crossed Nicol state in which the polarization axes are orthogonal to each other. It confirmed from the state of. And with respect to the width L in the longitudinal direction of the base film 1 having a rectangular shape, the length measured from one end of both ends in the longitudinal direction of the rectangular shape is L / 2. In this position, the orientation direction dm and the ridge line direction dp of the unit columnar lens 2 are parallel, the inclination angle θ is 0 ° in the in-plane minimum value in the center of the width direction TD, and the width The unit columnar lens 2 was formed on the base film 1 so that the in-plane maximum value at the side end in the direction TD was 23 °.
The ridge line direction dp of the unit columnar lens 2 is a direction orthogonal to the longitudinal direction of the rectangular shape of the base film 1. Therefore, the orientation direction dm of the molecular principal axis in the central portion in the width direction of the rectangular shape is also a direction orthogonal to the longitudinal direction of the rectangular shape of the base film 1.

The unit columnar lens 2 has a main cutting plane in which the main cutting surface has a height of 67 μm (elevation difference in the Z-axis direction between the valley portion 2v and the ridge line 2p), a curvature radius of 500 μm, and an F value of 1. It is a bowl-shaped lenticular lens whose surface shape is formed from a part of an ellipse. The unit columnar lens 2 has a width in the arrangement direction da and an arrangement period P of 500 μm, and completely covers one surface 1 p of the base film 1.
The alignment mark M has a cross shape as shown in FIG. 1B and has the dimensions shown in FIG.

  Next, an adhesive film for optical materials using a transparent acrylic adhesive on the other surface 1q of the base film 1 which is the back surface side of the columnar lens sheet for stereoscopic image display 10 (manufactured by Panac Industry Co., Ltd., PD -S1) was affixed, and the pressure-sensitive adhesive layer 4 having a thickness of 25 μm and having a surface protected by a separator film was laminated.

Next, the separator film is peeled off from the columnar lens sheet for stereoscopic image display 10 with the pressure-sensitive adhesive layer, and the columnar lens sheet for stereoscopic image display 10 is placed on one of the transparent glass substrates 5 via the pressure-sensitive adhesive layer 4. The optical member 20 for stereoscopic image display was produced by pasting on the surface. At this time, the alignment mark M was used to align the stereoscopic image display columnar lens sheet 10 and the glass substrate 5.
In addition, a periodic light beam control pattern 6 is formed on the other surface of the glass substrate 5, and the period thereof is the 500 μm array period P of the unit columnar lenses 2 in the array direction da of the unit columnar lenses 2. The black pattern has a corresponding period and extends in the same direction as the ridgeline 2 p of the columnar unit lens 2. The light beam control pattern 6 is a black matrix that is a light shielding pattern in the color filter formed on the front glass substrate of the liquid crystal panel. Further, a light-shielding alignment mark M2 having the same shape and the same size as the alignment mark M is provided at the same location corresponding to the alignment mark M.
In the liquid crystal panel, one pixel is composed of red, green, and blue sub-pixels, and a black matrix is formed around the sub-pixels.

[Examples 2 to 5]
In Example 1, the orientation direction dm of the molecular principal axis at the position of the center portion in the width direction in the longitudinal direction of the base film 1 (the portion where the distance from one end is L / 2) and the unit columnar shape The inclination angle θ formed by the ridge line of the lens 2 is replaced with a minimum value 0 ° and a maximum value 23 ° in the plane, and in Example 2, the minimum value 20 ° and the maximum value 32 ° are set in the plane. Example 3 has a minimum value of 40 ° and a maximum value of 46 ° in the plane, Example 4 has a minimum value of 45 ° and a maximum value of 48 ° in the plane, and Example 5 has a minimum value of 48 ° in the plane. The columnar lens sheet for stereoscopic image display 10 and the optical member for stereoscopic image display 20 were produced in the same manner as in Example 1 except that the maximum value was 50 °. The ridge line direction dp of the unit columnar lens 2 is a direction orthogonal to the longitudinal direction of the rectangular shape of the base film 1.

[Comparative Examples 1-2]
In Example 1, the orientation direction dm of the molecular principal axis at the position of the center portion in the width direction in the longitudinal direction of the base film 1 (the portion where the distance from one end is L / 2) and the unit columnar shape The inclination angle θ formed by the ridge line of the lens 2 is replaced with the minimum value 0 ° and the maximum value 23 ° in the plane, and in Comparative Example 1, the minimum value 70 ° and the maximum value 84 ° in the plane are compared. In Example 2, the stereoscopic image display columnar lens sheet 10 and the stereoscopic image display optical member 20 were produced in the same manner as in Example 1 except that the minimum value 83 ° and the maximum value 90 ° in the plane were set. . The ridge line direction dp of the unit columnar lens 2 is a direction orthogonal to the longitudinal direction of the rectangular shape of the base film 1.

[Performance evaluation]
The above-described stereoscopic image display optical member 20 was subjected to a reliability test for 1000 hours in an environment of 80 ° C., and the degree of change in the arrangement period P of the unit columnar lenses 2 was measured and evaluated.
Note that the dimensional change is considered to be within an allowable range without causing a dimensional change that causes crosstalk if the stereoscopic display system is a twin-lens system and is 100 ppm or less. However, since the observable range in principle is limited to the front view etc., the main application is a small display device, but the accumulated error of the arrangement period P of the unit columnar lenses 2 is substantially reduced because of the small size. Since it is smaller than the large size and the observable range is limited such as the front, it does not matter much. When viewing on a large-scale television such as a large number of people, a multi-view system of about 10 is often adopted, and in the case of a 10-eye system, the dimensional change is allowed up to 300 ppm. .
Therefore, if this allowable error is applied to the arrangement period P of 500 μm, 100 ppm is 0.05 μm and 300 ppm is 0.15 μm. For this reason, the performance evaluation is good when the dimensional change is 0.13 μm or less (260 ppm or less) from the viewpoint of safety (◯ in Table 1), and slightly better when it is 0.15 μm or less (Δ in Table 1). ), Exceeding 0.15 μm was evaluated as defective (indicated by x in Table 1).

As shown in Table 1, the first example in which the inclination angle θ is 0 ° and the maximum value 23 ° in the plane, and the example in which the inclination angle θ is the minimum value 20 ° and the maximum value 32 ° in the plane. 2. Example 3 in which the inclination angle θ is 40 ° and the minimum value 46 ° in the plane, and Example 4 in which the inclination angle θ is the minimum value 45 ° and the maximum value 48 ° in the plane, Also, it was good because it was less than the target dimensional change with a margin. Further, Example 5 having the inclining angle θ of the minimum value of 48 ° and the maximum value of 50 ° in the plane also remained below the target dimensional change and was slightly good. However, Comparative Example 1 in which the inclination angle θ is in-plane minimum value 70 ° and maximum value 84 °, and Comparative Example 2 in which the inclination angle θ is in-plane minimum value 83 ° and maximum value 90 ° are the target. It exceeded the dimensional change and was defective.
For this reason, in each comparative example, when used in a stereoscopic image display device of a lenticular system, there is a possibility that luminance decreases due to crosstalk of left and right parallax images and visual recognition of a black matrix that is a light beam control pattern over time. However, in each embodiment, it is expected that a stereoscopic image with high quality can be displayed over time without causing a reduction in luminance due to crosstalk of the left and right parallax images or visual recognition of the black matrix.
Further, the alignment mark M facilitates the alignment.

1 Base film 1p One surface 1q The other surface 2 Unit columnar lens 2p Ridge (top)
2v Valley part 3 Columnar lens group 4 Adhesive layer 5 Glass substrate 6 Light beam control pattern 10 Columnar lens sheet 20 for stereoscopic image display Optical member 30 for stereoscopic image display Liquid crystal display device 31 Light source 32 Liquid crystal panel 32a Front glass substrate 32b Rear glass substrate 32c Liquid crystal layer (pixel layer)
A Effective screen area Bd Boundary da One direction (= array direction)
dm Alignment direction of molecular principal axis dp Edge direction L Width in alignment direction M Alignment mark M2 Matement alignment mark M + M2 Shape during alignment Mg Guide mark Ms serving as a mark for the position of alignment mark Small piece of alignment mark n Normal P Arrangement period S Observer θ Inclination angle (Inferior angle formed by ridge line and molecular principal axis)

Claims (3)

The unit columnar lens has a columnar lens group in which unit columnar lenses are arranged in one direction parallel to each other on one surface of the substrate film, and the orientation direction of the molecular principal axis of the resin constituting the substrate film and the unit columnar lens The inclination angle θ defined as a subordinate angle among the angles formed in the plane parallel to one surface of the base film is 0 ° ≦ θ ≦ 50 ° in the entire region of the base film. And
A columnar lens sheet for stereoscopic image display, having at least two alignment marks per sheet on the surface of the columnar lens group outside the effective screen area.   The alignment mark is made of the same material as the columnar lens group, and the alignment mark has a convex shape with respect to the columnar lens group, and there is no interface between the alignment mark and the columnar lens group. The columnar lens sheet for stereoscopic image display according to claim 1, which is integrated by layers. A liquid crystal display device, wherein the columnar lens sheet for stereoscopic image display according to claim 1 or 2 is installed on a screen of a liquid crystal panel, and a planar image of the liquid crystal panel is displayed as a stereoscopic image.

Images