JP2010181610A - Optical part and image display device using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical part reducing the effect of a black matrix; and to provide an image display device using the optical part. <P>SOLUTION: The sheet-type optical part includes a plurality of lenses 12a, contains a projecting side 12b extending in a first direction, and is arranged in a second direction perpendicular to the first direction. Each projecting side of the plurality of lenses includes a first region 12d and two second regions 12 which are on both sides of the first region in the second direction. The first region has a constant curvature, and the absolute value of inclination of the second region in the second direction is below an absolute value of inclination of the first region in the second direction at the edge in the second direction. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an optical component and an image display device using the same.

  There is a display device that displays different images for a plurality of viewpoints by combining a display panel such as a liquid crystal device and a lenticular lens having cylindrical lenses arranged in an array. For example, in a car navigation application, such a display device is used to make different images visible from a driver seat and a passenger seat. Such a display device may be used as a stereoscopic image display device that allows an observer to recognize a stereoscopic image by showing different images to the right eye and the left eye.

  Japanese Patent Laid-Open No. 2008-134617 discloses an example in which a lenticular lens is used in a stereoscopic image display device. In the display panel of this stereoscopic image display device, the right-eye pixels and the left-eye pixels are alternately arranged, and the right-eye image is displayed on the right side and the left-eye image is displayed on the left side by the lenticular lens. It is formed. As a result, an image formed by the right-eye pixels is formed on the retina of the observer's right eye, and an image formed by the left-eye pixels is formed on the left-eye retina.

JP 2008-134617 A

  Generally, a light-shielding portion called a black matrix is provided between pixels of a liquid crystal device. Due to such a black matrix, a black region corresponding to the image of the black matrix is generated at the viewing position of the observer. With this black matrix, depending on the viewing position, black streaks and stripes are observed in the image. Therefore, in the conventional stereoscopic image display apparatus, the image quality may be deteriorated.

  An object of the present invention is to provide an optical component capable of reducing the influence of a black matrix, and an image display device using the optical component.

  The optical component of the present invention is a sheet-like optical component. This optical component includes a plurality of lenses. The plurality of lenses includes a convex surface extending in the first direction. The plurality of lenses are arranged in a second direction orthogonal to the first direction. Each convex surface of the plurality of lenses includes a first region and two second regions existing on both sides of the first region in the second direction. The first region has a certain curvature. The absolute value of the inclination of the second region with respect to the second direction is equal to or less than the absolute value of the inclination of the first region with respect to the second direction at the edge in the second direction.

  According to this optical component, part of the light emitted from the second region reaches the region corresponding to the black matrix, thereby reducing the influence of the black matrix.

  The optical component of the present invention preferably has a uniform surface on the side opposite to the convex surface. Further, the radius of curvature of the second region may be larger than the radius of curvature of the first region. Each of the second regions may be a plane having a certain inclination with respect to the second direction. The absolute value of the slope of the second region may be equal to the absolute value of the slope of the first region at the edge.

  Another aspect of the present invention relates to an image display device. The image display device includes a display panel in which a plurality of pixels including pixels that display an image for a first viewpoint and pixels that display an image for a second viewpoint are arranged in a matrix, and the optical component of the present invention described above. And an optical sheet for emitting light from the display panel from the convex surface.

  According to this image display device, since the influence of the black matrix is reduced, a higher quality image than that of the conventional display device is provided.

  As described above, according to the present invention, an optical component capable of reducing the influence of the black matrix and an image display device using the same are provided.

1 is a diagram schematically illustrating an image display device according to an embodiment. It is an enlarged view of the lens in the optical component of the image display apparatus shown in FIG. It is a figure which shows the locus | trajectory of the light ray in the conventional lenticular lens, and the locus | trajectory of the light ray in the lens in the optical component of the image display apparatus shown in FIG. It is an enlarged view of the lens in the optical component which concerns on another embodiment. It is a figure which shows the various parameters in an image display apparatus. 6 is a diagram illustrating a relationship between a position in a second direction Y on the image plane of the image display apparatus according to Embodiment 1 and light intensity. FIG. FIG. 10 is a diagram illustrating a relationship between a position in a second direction Y on the image plane of the image display apparatus of Example 2 and light intensity. It is a figure which shows the relationship between the position in the 2nd direction Y in the image surface of the image display apparatus of a comparative example, and light intensity.

  DESCRIPTION OF EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals.

  FIG. 1 is a plan view schematically showing an image display apparatus according to an embodiment. FIG. 1 schematically shows an image display device according to an embodiment in an arbitrary cross section along the ZY plane in the drawing.

  The image display device 1 illustrated in FIG. 1 includes a display panel 10 and an optical component 12. The display panel 10 is a liquid crystal device, for example. The display panel 10 has a plurality of pixels 10a and 10b. The display panel 10 has a plurality of pixel columns extending in the first direction X. In the display panel 10, a pixel column including a plurality of pixels 10 a and a pixel column including a plurality of pixels 10 b are alternately arranged in a second direction Y orthogonal to the first direction X. The plurality of pixels 10a are pixels that provide an image for the right viewpoint, and the plurality of pixels 10b are pixels that provide an image for the left viewpoint.

  The optical component 12 has a plurality of lenses 12a. The plurality of lenses 12a are arranged in the second direction Y. Each of the plurality of lenses 12 a includes a convex surface 12 b extending in the first direction X. The surface 12c opposite to the convex surface of the plurality of lenses 12a is a uniform surface, that is, a flat surface.

  FIG. 2 is an enlarged view of a lens in the optical component of the image display apparatus shown in FIG. As shown in FIG. 2, the convex surface 12b of the lens 12a includes a first region 12d and two second regions 12e located on both sides of the first region 12d in the second direction Y. .

  In the present embodiment, the first region 12d is a region having a constant radius of curvature R1. The absolute value of the inclination of the second region 12e with respect to the second direction Y is equal to or less than the absolute value of the inclination of the first region 12d with respect to the second direction Y at the edge in the second direction Y. The absolute value of the inclination of the first region 12d at the edge in the second direction Y with respect to the second direction Y is the arc from the center position of the convex surface 12b to the edge of the first region 12d in the Y direction If the apex angle of the sector formed by the center of the circumference including the arc is θ, it can be expressed as | tan θ |. Note that θ = sin−1 (w / 2 / R1), where w is the width of the first region 12d. In the present embodiment, the second region 12e is also a region having a constant curvature radius R2, and the curvature radius R2 is larger than the curvature radius R1.

  FIG. 3 is a diagram showing a ray trajectory in a conventional lenticular lens and a ray trajectory in a lens in the optical component of the image display apparatus shown in FIG. In the conventional display device, the convex surface of the lenticular lens is formed with a constant curvature, and as shown in FIG. 3A, the light emitted from one point of the pixel forms an image for the left viewpoint on the image plane IP. One of the region IL to be imaged and the region IR on which the right viewpoint image is formed is incident. Therefore, no light enters the region B on the image plane IP corresponding to the black matrix between the pixels 10a and 10b.

  On the other hand, as shown in FIG. 3B, a part of the light emitted from the convex surface 12b of the lens 12a of the present embodiment also enters the region B. This is because the spread of the light emitted from the second region 12e is larger than the spread of the light emitted from the first region 12d and enters the region B as well. Thereby, the image quality of the image formed on the image plane IP is improved.

  Hereinafter, an optical component according to another embodiment will be described. FIG. 4 is an enlarged view of a lens in an optical component according to another embodiment. On the convex surface 12b of the lens 12a of the optical component shown in FIG. 4, the second region 12e has the same inclination as the absolute value | tan θ | of the inclination of the first region 12d at the edge with respect to the second direction Y. is doing. The inclination of each second region 12e is constant in the second region 12e. Therefore, the second region 12e is a plane. The optical component having such a lens 12a can also reduce the influence of the black matrix.

  The present invention is not limited to the above-described embodiment, and various modifications can be made. For example, in the above-described embodiment, the surface 12c of the optical component 12 and the display panel 10 are in contact with each other, but glass, an adhesive, other optical components, or the like may be inserted therebetween. In this case, it is necessary to determine the lens parameters in consideration of the refractive index and thickness of each component. However, these parameters can be set by calculating a ray matrix, or for optical design. Calculation and optimization can be easily performed using a commercially available simulator.

  Further, although the above-described embodiment is a two-viewpoint image display device, the idea of the present invention can be applied to an image display device having a larger number of viewpoints. Of course, the idea of the present invention is not limited to stereoscopic image display, and can also be applied to a display device that displays different images from a plurality of viewpoints such as an in-vehicle dual display.

  Furthermore, in the above-described embodiment, the second region has a certain curvature or a flat surface, but the shape of the second region is made more complex, and the optimal light intensity on the image plane By providing the distribution, it is possible to provide a higher quality image. Such a surface shape can be designed using an optimization function of a commercially available simulator for optical design.

  Hereinafter, the present invention will be described in more detail by using an image display apparatus simulated based on the present invention as an example. However, the present invention is not limited to the following example.

  First, the image display apparatus shown in FIG. 1 and having the lens having the shape shown in FIG. FIG. 5 shows various parameters in the image display apparatus.

  In Example 1, the pitch P between the pixels is 0.15 mm, the lens thickness t is 1.05 mm, the refractive index n of the lens is 1.5, and the aperture ratio w1 / P of each pixel is 0.7 (w1 is each Pixel width), the distance w2 between the center of the region IR where the right viewpoint image is formed and the region IL where the left viewpoint image is formed is 64 mm, and the distance L from the image plane IP to the convex surface of the lens is 300 mm. did.

  Next, the image display apparatus shown in FIG. 1 and having the lens having the shape shown in FIG. The parameters in Example 2 were the same as those in Example 1 except that each of the second regions was a plane having the same inclination as that of the edge of the first region.

  Further, for comparison, an image display device having an optical component having a convex surface formed with a certain curvature and a display panel was simulated as a comparative example. The parameters in the comparative example were the same as those in Example 1 except that the curvature radius R of the convex surface was a constant 0.36 mm.

  6 to 8 show the relationship between the position in the second direction Y on the image plane and the light intensity for each of the image display devices of Example 1, Example 2, and Comparative Example. As shown in FIG. 8, in the comparative example, an area where the light intensity is 0 exists in the image plane in the area between the viewpoints. On the other hand, as shown in FIG. 6, in Example 1, the light intensity in the region between the viewpoints was not zero. That is, in Example 1, light entered the region between the viewpoints. Therefore, in Example 1, it was confirmed that the image quality was improved compared to the comparative example.

  In Example 2, the width w in the second direction Y of the first region was changed to 0.24 mm, 0.18 mm, and 0.15 mm, respectively. In Example 2, as shown in FIG. 7, in addition to light entering the region between the viewpoints, a smooth light intensity distribution was also obtained in Example 1. Further, as is clear from FIG. 7, it was confirmed that a more uniform light intensity distribution can be obtained by changing the width w in the second direction Y of the first region.

DESCRIPTION OF SYMBOLS 1 ... Image display apparatus, 10 ... Display panel, 10a, 10b ... Pixel, 12 ... Optical component, 12a ... Lens, 12b ... Convex surface, 12c ... Surface, 12d ... 1st area | region, 12e ... 2nd area | region, IP ... Image plane, IL: imaging region for left viewpoint image, IR: imaging region for right viewpoint image.

Claims (6)

A sheet-like optical component,
A plurality of lenses including a convex surface extending in a first direction, the lenses arranged in a second direction orthogonal to the first direction;
Each convex surface of the plurality of lenses includes a first region and two second regions existing on both sides of the first region in the second direction,
The first region has a constant curvature;
The absolute value of the inclination of the second region with respect to the second direction is less than or equal to the absolute value of the inclination of the first region with respect to the second direction at the edge in the second direction;
Optical component.   The optical component according to claim 1, wherein the optical component has a uniform surface opposite to the convex surface.   The optical component according to claim 1 or 2, wherein a radius of curvature of the second region is larger than a radius of curvature of the first region.   Each of the said 2nd area | region is an optical component of Claim 1 or 2 which is a plane which has a fixed inclination with respect to the said 2nd direction.   The optical component according to claim 4, wherein an absolute value of the inclination of the second region is equal to an absolute value of the inclination of the first region at the edge. A display panel in which a plurality of pixels including pixels that display an image for a first viewpoint and pixels that display an image for a second viewpoint are arranged in a matrix;
The optical component according to any one of claims 1 to 5, wherein the optical component that emits light from the display panel from the convex surface;
An image display device comprising:

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