JP2010048894A - Stereoscopic display - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a polarizing element which solves such a problem that an error occurs in the pitch of the two kinds of polarizing pieces of the polarizing element and image quality is degraded because an image is colored by the birefringence effect of a half-wavelength plate and to provide a method for manufacturing the polarizing element. <P>SOLUTION: In the polarizing element, a first polarization control plate having such a configuration that a polarizing piece having polarizance in a stripe shape and a transparent part not having polarizance are alternately repeated and a second polarization control plate including a polarizing piece having a polarizing axis direction different from that of the first polarization control plate and the transparent part are integrated so that the two kinds of polarizing pieces having the polarizing axis directions different from each other are repeatedly arranged in a predetermined direction. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a stereoscopic display that performs stereoscopic display in a television, a computer monitor, a game machine, or the like.

  Conventionally, stereoscopic image observation methods include, for example, a method of observing parallax images based on different polarization states using polarized glasses, or a plurality of parallax images (viewpoint images) using a lenticular lens without using glasses. A method for guiding a predetermined parallax image to the eyeball of the observer has been proposed.

  Among these, in a stereoscopic image display device (stereoscopic display) using polarized glasses, the polarization state is different for the left eye image and the right eye image, and the left and right images are separated using polarized glasses.

  As one of the methods, a polarization control plate in which half-wave plates and transparent portions are alternately arranged in horizontal stripes is arranged on the surface of the liquid crystal display, and the pitch of the horizontal stripes is set in the display pixel portion of the liquid crystal display. Correspondingly, the left eye image and the right eye image are alternately displayed as a horizontal stripe parallax image. For this reason, the right eye image and the left eye image, each having a different polarization axis direction, are guided to the observer side, and the observer wears polarized glasses with polarizing films attached to the left and right eyes respectively corresponding to the polarization axis directions of the left and right eye images. There is a method of performing stereoscopic viewing.

  In order to further expand the stereoscopic viewing area, Japanese Patent Laid-Open No. 10-221643 enables stereoscopic viewing using an optical element in which a horizontal lenticular lens is combined with a polarization control plate. FIG. 5 is a side sectional view of a display of this type. Reference numeral 101 denotes a liquid crystal display for image display, 102 denotes a glass substrate, and 103 denotes a display pixel portion. A glass substrate (not shown) similar to the glass substrate 102 is arranged on the back surface (backlight side) of the display pixel portion 103, and a backlight (not shown) is arranged on the back surface. A polarizing plate is disposed on the front surface of the glass substrate 102, but is not shown in the figure. The light beam from the display pixel unit 103 is emitted as linearly polarized light having a polarization direction of 45 degrees by a polarizing plate disposed in front of the liquid crystal display 101.

  105 is a lenticular lens in which horizontal stripe-shaped cylindrical lenses 105a having refractive power in the vertical direction (V direction) are arranged at a predetermined pitch in the vertical direction, and 106 is a polarization control plate. On the polarization control plate 106, half-wave plates 106a and transparent portions 106b are alternately arranged at a predetermined pitch in the vertical direction. Here, the cylindrical lens 105a is on the viewer direction side, and the lens radius of the cylindrical lens 105a, the display pixel unit 103, the polarization control plate 106, and the lenticular so that the light beam from the display pixel unit 103 forms an image on the polarization control plate 106. The interval between the lenses 105 is set.

  Next, an optical path in which the light flux from the display pixel unit 103 travels in the observer direction will be described with reference to FIG.

The luminous flux from the display pixel unit 103 is focused on the half-wave plate 106 a or the transparent portion 106 b of the polarization control plate 106 on a one-to-one basis by the lenticular lens 105. For example, in FIG. 6, the right eye image R is designed to form an image on the transparent portion 106b, and the left eye image L is designed to form a one-to-one image on the half-wave plate 106a. Therefore, one pixel of the left and right eye images of the display pixel unit 103 is formed on the polarization control plate 106 as shown in the figure. Since the pitch of the lenticular lens 105 and the polarization control plate 106 corresponds to the pitch of the display pixel unit 103, the right eye image R is the transparent portion 106b and the left eye image L is the half wavelength for all other pixels. One-to-one image is formed on the plate 106a. Since the right eye image R is transmitted through the transparent portion 106b, the polarization direction is maintained at 45 degrees. Since the left eye image L is transmitted through the half-wave plate 106a, the polarization direction is rotated by 90 degrees and becomes -45 degrees. That is, when the left and right eye images pass through the polarization control plate 106, the left and right eye images have polarization directions orthogonal to each other. Since the light transmitted through the polarization control plate spreads at the observation distance as shown in the figure, the observer obtains a wide vertical stereoscopic viewing area. An observer can perform stereoscopic viewing by applying polarized glasses with polarizing films attached to the left and right eyes respectively corresponding to the polarization axis directions of the left and right eye images.
Japanese Patent Laid-Open No. 10-221463

  In the conventional stereoscopic image observation method, in the observation method without glasses using a lenticular lens or the like, the range in which the stereoscopic image can be seen is determined in principle, and thus it is not possible to observe a plurality of images. However, there was a problem that fatigue was accumulated because the fixed position was forced for a long time.

  On the other hand, in a stereoscopic display using a polarization control plate, in the case of three-dimensional display, a stereoscopically visible region (vertical stereoscopic viewing region) is generated in the vertical direction of the screen. Therefore, by arranging a lenticular lens on the incident surface of the polarization control plate There has been a proposal of Japanese Patent Laid-Open No. 10-221643 which attempts to enlarge the vertical stereoscopic viewing area.

  However, by arranging the lenticular lens on the incident surface of the polarization control plate, there is a problem that when the image is viewed, the image is blurred and a clear image cannot be observed.

  The cause of this will be described with reference to FIG.

  FIG. 7 illustrates an optical path at an arbitrary point on one scanning line of the right eye image R. A solid line 201 is an optical path that travels in the viewer direction by the cylindrical lens 105a that is the shortest distance from one scanning line of the right eye image R. A dotted line 202 is an optical path by the cylindrical lens 5a adjacent to the cylindrical lens 105a incident by the solid line 201. As shown in FIG. 7, the solid line 201 and the dotted line 202 have an optically overlapping region 203 after passing through the polarization control plate 106. When the observer is in a region 203 where the solid line 201 and the dotted line 202 overlap, the light flux of the solid line 201 coming out from a certain point in the right eye image R and the solid line 201 of the right eye image R from a different point. A phenomenon occurs in which the light beam is visible to the observer, that is, one scanning line of the right eye image R is doubled.

  This phenomenon occurs even in the left-eye image L because the display pixel portion 103, the lenticular lens 105, and the polarization control plate 106 have corresponding pitches.

  An object of the present invention is to provide a stereoscopic display in which an image can be clearly seen even if a lenticular lens for expanding a stereoscopic viewing area is arranged on an incident surface of a polarization control plate.

  A horizontal stripe composite parallax image obtained by dividing the left-eye parallax image and the right-eye parallax image into a plurality of horizontal stripe parallax images, and alternately and repeatedly arranging the divided stripe parallax images on the display at a predetermined pitch in the vertical direction. And two types of horizontal stripe-shaped regions that perform conversion in which the polarization directions are orthogonal to each other, and a first lenticular lens arranged in a vertical direction in order in the viewer direction of the horizontal stripe composite parallax image Using a polarization control plate arranged alternately at a predetermined pitch in the vertical direction and an optical element including a second lenticular lens arranged at a predetermined pitch in the vertical direction. It is characterized by.

  It is characterized in that the polarization control plate is stereoscopically observed by using a polarization control plate comprising two types of stripe-shaped regions of a transparent portion and a half-wave plate.

  The optical element is characterized in that the second lenticular lens is stereoscopically observed by using a barrier in which openings and light shielding portions are alternately arranged at a predetermined pitch in the vertical direction.

  As described above, according to the present invention, a three-dimensional display suitable for observation by a large number of people can be achieved by using an optical element in which a lenticular lens and a striped polarization control plate are combined.

  In the conventional optical element, one scanning line looks double due to the lenticular lens, causing image quality blur and deterioration. In this embodiment, by adding a lenticular lens or a barrier to the conventional optical element, the parallel light is guided to the viewer side, so that one scanning line does not look double, and a clear stereoscopic image is observed. Can do.

  Next, details of the present invention will be described in accordance with the description of the embodiments.

  FIG. 1 is a side sectional view of the first embodiment, and FIG. 2 is an explanatory view of the stereoscopic observation principle of FIG.

  In FIG. 1, 1 is a liquid crystal display for image display, 2 is a glass substrate, and 3 is a display pixel portion. A glass substrate (not shown) similar to the glass substrate 2 is arranged on the back surface (backlight side) of the display pixel unit 3, and a backlight (not shown) is arranged on the back surface. Further, a polarizing plate is disposed on the front surface of the glass substrate 2, but is omitted in the figure.

  The light beam from the display pixel unit 3 is converted into linearly polarized light having a polarization direction of 45 degrees by polarizing plates arranged before and after the liquid crystal display 1.

  In the display pixel unit 3, two parallax images (R for the right eye image and L for the left eye image) corresponding to the two viewpoints for the right eye and the left eye are alternately arranged in horizontal stripes in the vertical direction (V direction) of the screen. Are arranged and displayed.

  Reference numeral 4 denotes an optical element that guides a horizontal stripe composite parallax image from the liquid crystal display 1 to an observer. The optical element 4 includes a first lenticular lens 5, a polarization control plate 6, and a second lenticular lens 7 from the backlight side.

  In the first lenticular lens 5, horizontal stripe-shaped cylindrical lenses 5 a having refractive power in the vertical direction (V direction) are repeatedly arranged at a predetermined pitch in the vertical direction (V direction), and the cylindrical lens 5 a is arranged on the liquid crystal display 1. It arrange | positions so that a convex surface may face. The pitch of the first lenticular lens 5 corresponds to each of the horizontal stripe parallax images (parallax images R and L) of the display pixel unit 3.

  A polarization control plate 6 is disposed on the viewer side of the first lenticular lens 5. In the polarization control plate 6, horizontal stripe-shaped half-wave plates 6a and transparent portions 6b are alternately and repeatedly arranged in the vertical direction (V direction). The pitch between the half-wave plate 6 a and the transparent portion 6 b corresponds to the pitch of the first lenticular lens 5.

  The lens radius of the cylindrical lens 5a, the display pixel unit 3, and the first lenticular lens 5 are formed so that an image of one scanning line is formed on the half-wave plate 6a or the transparent portion 6b of the polarization control plate 6 on a one-to-one basis. The distance between the polarization control plate 6 is set.

  Next, a second lenticular lens 7 is disposed on the observer side of the polarization control plate 6. As with the first lenticular lens 5, the horizontal lenticular lens 7 is configured by arranging horizontal stripe-shaped cylindrical lenses 7a in the vertical direction. The pitch of the second lenticular lens 7 corresponds to the pitch of the polarization control plate 6. Further, the lens radius of the cylindrical lens 7 a and the distance between the second lenticular lens 7 and the polarization control plate 6 are set so that the focal plane of the cylindrical lens 7 a becomes the polarization control plate 6.

  The first lenticular lens 5, the polarization control plate 6 and the second lenticular lens 7 constituting the optical element 4 can be integrated with an adhesive or the like. In this case, it should be noted that an image of one scanning line is formed on the half-wave plate 6a or the transparent portion 6b of the polarization control plate 6 on a one-to-one basis and the focal plane of the cylindrical lens 7a is the polarization control plate 6. The lens radius of the cylindrical lens 5a, the distance between the display pixel unit 3, the first lenticular lens 5 and the polarization control plate 6, the lens radius of the cylindrical lens 7a, and the distance between the second lenticular lens 7 and the polarization control plate 6 Set.

  FIG. 2 is a diagram for explaining an arbitrary optical path of one scanning line of the right eye image R. A solid line 21 in the figure is an optical path in which a light beam emitted from an arbitrary point of the right eye image R enters the cylindrical lens 5a at the shortest distance from the right eye image R and travels in the direction of the viewer.

  The light beam indicated by the solid line 21 enters the cylindrical lens 5a corresponding to the right-eye image R shown in the figure, and forms an image on the transparent portion 6b of the polarization control plate 6 corresponding to the cylindrical lens 5a in a one-to-one manner.

  Next, the light beam formed on one point of the transparent portion 6 b enters the second lenticular lens 7. At this time, since the polarization control plate 6 is disposed on the focal plane of the second lenticular lens 7, the condensed light beam is emitted from the second lenticular lens 7 along an optical path close to parallel light. The emitted light beam travels in the direction of the viewer along an optical path close to parallel light.

  A dotted line 22 in the figure is an optical path in which a light beam emitted from one point different from the solid line 21 of the right eye image R is incident on a lens adjacent to the cylindrical lens 5a incident on the solid line 21 and travels in the observer direction.

  Since the pitches of the polarization control plate 7, the first lenticular lens 5, and the display pixel unit 3 correspond to each other, the light beam incident on the lens adjacent to the cylindrical lens 5a used in the solid line 21 forms an image in the solid line 21. One-to-one imaging is performed on another transparent portion 6b adjacent to the transparent portion 6b.

  The light beam formed on one point of the transparent portion 6b of the dotted line 22 passes through the second lenticular lens 7, and is emitted by the second lenticular lens 7 along an optical path close to parallel light, and reaches the observer's eyes.

  Since the solid line 21 and the dotted line 22 are optical paths close to parallel light, there is almost no overlapping area at the optimum distance for observing a stereoscopic image (optimum observation distance). Since the pitches of the lenticular lens 5 and the display pixel unit 3 correspond to each other, the same can be said.

  For this reason, one scanning line does not appear to be double, and the observer can see a clear stereoscopic image by applying the polarizing glasses 40.

  FIG. 3 is a side sectional view of the second embodiment, and FIG. 4 is an explanatory view of the stereoscopic observation principle of FIG.

  The difference from the first embodiment is that the second lenticular lens 7 of the optical element 4 is changed to a barrier 8.

  In FIG. 3, the barrier 8 is configured by alternately arranging openings 8 a and light shielding portions 8 b in the V direction. The pitch of the pair of the opening 8a and the light shielding portion 8b corresponds to the pitch of the polarization control plate 6.

  FIG. 4 is a diagram for explaining an optical path of a light beam from an arbitrary point on one scanning line of the right eye image R. The solid line 31 in the figure is an optical path in which an arbitrary point of the right eye image R enters the cylindrical lens 5a at the shortest distance from the right eye image R and travels in the direction of the viewer.

  As in the first embodiment, an arbitrary point of the right eye image R is imaged on the transparent portion 6b of the polarization control plate 6 on a one-to-one basis. The light beam that has passed through the polarization control plate 6 travels to the barrier 8 as indicated by the solid line 31, exits only from the opening 8a, and travels in the direction of the viewer.

  If the sizes of the opening 8a and the light-shielding portion 8b and the distance between the polarization control plate 6 and the barrier 8 are optimally set, the luminous flux of the image traveling in the observer direction becomes an optical path close to parallel light. The arrangement position of the aperture 8a and the barrier 8 takes an optimum value as appropriate in consideration of the optimum observation distance, the pitch between the first lenticular lens 5 and the polarization control plate 6, and the like.

  A dotted line 32 in the figure is an optical path in which one point of the right-eye image R similar to the solid line 31 is incident on a lens adjacent to the cylindrical lens 5a incident on the solid line 31 and travels in the observer direction. In the same manner as in the first embodiment, a one-to-one image is formed on another transparent portion 6 adjacent to the transparent portion 6b of the polarization control plate 7 through which the solid line 31 has passed.

  The light beam that has passed through the polarization control plate 7 enters the barrier 8 and exits through an optical path close to parallel light. For this reason, since the solid line 31 and the dotted line 32 are optical paths close to parallel light, there is very little area where they overlap until they reach the optimum distance (optimum observation distance) for observing a stereoscopic image, and one scanning line is doubled. And the observer can see a clear stereoscopic image by applying polarized glasses 40.

Side sectional view of Example 1 Explanatory drawing of the observation principle of the stereoscopic vision of Example 1 Side sectional view of Example 2 Explanatory drawing of the observation principle of the stereoscopic vision of Example 2 Side sectional view of a conventional 3D display using polarized glasses Explanatory drawing of the optical path which advances to the observer direction of the 3D display of the conventional polarized glasses system Explanatory drawing of the optical path of the arbitrary one points of the right eye image R of the 3D display of the conventional polarized glasses system

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Liquid crystal display 2 Glass substrate 3 Display pixel part 4 Optical element 5 1st lenticular lens 5a Cylindrical lens 6 Polarization control board 6a Half-wave plate 6b Transparent part 7 2nd lenticular lens 7a Cylindrical lens 8 Barrier 8a Opening part 8b Shading part

Claims (3)

  A horizontal stripe composite parallax image obtained by dividing the left-eye parallax image and the right-eye parallax image into a plurality of horizontal stripe parallax images, and alternately and repeatedly arranging the divided stripe parallax images on the display at a predetermined pitch in the vertical direction. Two types of conversion for making the polarization directions orthogonal to each other, and a first lenticular lens arranged in a vertical direction at a predetermined pitch in order on the viewer direction side of the horizontal stripe composite parallax image on the front surface of the display 3D observation by using an optical element with a polarization control plate in which horizontal stripe regions are alternately arranged at a predetermined pitch in the vertical direction and a second lenticular lens arranged at a predetermined pitch in the vertical direction A three-dimensional display characterized by doing so.   The three-dimensional display according to claim 1, wherein the polarization control plate is stereoscopically observed by using a polarization control plate composed of two types of stripe-shaped regions of a transparent portion and a half-wave plate.   2. The optical element according to claim 1, wherein the second lenticular lens is a three-dimensional observation by using a barrier in which openings and light-shielding portions are alternately arranged at a predetermined pitch in the vertical direction. 3D display.

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