JP2011158777A - Stereoscopic image display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a stereoscopic display device which has a bright screen reduced in flicker and cross-talk without causing the deterioration of a resolution. <P>SOLUTION: The stereoscopic display device includes: a liquid crystal display having a first image-forming region and a second image-forming region which are composed of a plurality of horizontal lines; and optical means having a first polarization region and a second polarization region disposed correspondingly to the first image-forming region and the second image-forming region, respectively, and a light shield placed at a boundary of them. Frame images for a right eye and a left eye are displayed in the first image-forming region and the second image-forming region, respectively, and these regions are alternately switched or overwritten each time when the frames are switched to each other. The lighting control of a backlight is synchronized with the timing of switching between the first image-forming region and the second image-forming region and the state of a phase difference between the right and left parts of polarization glasses is alternately switched. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a stereoscopic image display device.

  In recent years, liquid crystal televisions using a liquid crystal display have been actively developed. As one of the efforts toward higher performance, development of a stereoscopic image display device using a liquid crystal display is being promoted.

  For a stereoscopic image display device using this liquid crystal display device, a plurality of types of methods have been proposed. For example, a parallax barrier method, a lenticular lens method, a switch backlight method, and the like are known. Although these have the advantage of not requiring special glasses for the viewer of the image from the display device, the resolution of the image display is generally reduced, such as the horizontal resolution is reduced in the parallax barrier method and the lenticular lens method. In the switch backlight type, there is a problem that flicker which is flickering of an image occurs.

  As a method using dedicated glasses, a shutter glasses method is known. This method has the advantage that the resolution is not lowered and the viewing angle of the display in the image display device is widened. However, there are problems such as flicker that is a flickering of the display image, a decrease in luminance on the display screen, and a time difference between the images displayed on the left and right eyes, which makes it impossible for the observer to obtain a natural image. is doing.

  Recently, a stereoscopic image display apparatus that obtains a stereoscopic image using a novel optical means has been proposed. For example, Patent Document 1 discloses a stereoscopic image display device that uses two polarizing filters as such a novel optical means and does not require dedicated glasses.

  In the stereoscopic image display device described in Patent Document 1, a right-eye polarizing filter section and a left-eye polarizing filter section whose polarization directions are orthogonal to each other are arranged on the front and right sides of the light source. Then, each light that has passed through each filter section is irradiated onto the liquid crystal display as substantially parallel light by a Fresnel lens. Then, each of the polarizing filters on both sides of the liquid crystal display is alternately arranged with the linear polarizing filter line portions orthogonal to each other for each horizontal line, and the linear polarizing filter line portions facing each other on the light source side and the viewer side are orthogonal. The polarization direction to be used. The liquid crystal panel of the liquid crystal display is configured to alternately display the video information for the right eye and the left eye for each horizontal line according to the light transmission lines of the two polarizing filters.

  In other words, all horizontal scanning lines on the display screen are divided into odd and even lines, and left and right eye images are displayed on each line, and these are distributed to the left and right eyes of the observer with the new optical means. A stereoscopic image is displayed.

  According to this apparatus, even if the viewer's viewing position is slightly shifted left and right, the stereoscopic image is not damaged, and the horizontal resolution, which is a problem in the parallax barrier method and the lenticular lens method, is halved. Can be avoided.

  Further, in Patent Document 2, as a new optical means, a three-dimensional structure using a new phase difference plate having two different regions that are arranged opposite to two different regions and that make the polarization axes of incident light orthogonal to each other. An image display device is disclosed. This stereoscopic image display device includes a liquid crystal display that displays a right-eye image and a left-eye image in different regions, and a phase difference plate thereof, and projects a parallax image to a viewer to generate a stereoscopic image. It is comprised so that can be obtained. It is known to display a high resolution image with a wide viewing angle.

JP-A-10-63199 JP 2006-284873 A

  However, in the stereoscopic image display device using the polarizing filter described in Patent Document 1, the display position according to the right-eye video signal and the display position according to the left-eye video signal on the display screen are always fixed, so Both have a new problem that the vertical resolution is halved.

  Further, in the stereoscopic image display device using the new phase difference plate described in Patent Document 2, the right-eye image on the liquid crystal display is observed when observed from a certain viewing angle position with respect to the vertical center of the stereoscopic display device. Has a new problem that it passes through the half-wave plate for the left eye and reaches the left eye of the observer to cause crosstalk.

  Therefore, in order to reduce flicker and crosstalk, maintain a high luminance on the screen, and prevent a decrease in resolution, a conventional stereoscopic image display device is insufficient, and a new stereoscopic image display device is required. It has been.

  The present invention has been made in view of these points. That is, an object of the present invention is to provide a stereoscopic image display device that has no flicker, has reduced crosstalk, has high screen brightness, can simultaneously view left and right images, and has no reduction in screen resolution. It is in.

  Other objects and advantages of the present invention will become apparent from the following description.

According to a first aspect of the present invention, there is provided a liquid crystal display having a liquid crystal panel configured by arranging a plurality of horizontal lines in which pixels are arranged in the horizontal direction in the vertical direction, and a pair of polarizing plates sandwiching the liquid crystal panel. ,
A backlight arranged on the back side of the liquid crystal display;
Optical means provided on the front side of the liquid crystal display;
A stereoscopic image display device comprising polarized glasses used by an observer,
The liquid crystal display includes a first image forming area and a second image forming area which are configured by bundling a plurality of horizontal lines continuously arranged in the vertical direction of the liquid crystal panel and are alternately arranged. The image formation area is configured to display either one of the right-eye image or the left-eye image, and the second image formation area is configured to simultaneously display the other image.
The first image forming area and the second image forming area are (1) the image for the right eye and the image for the left eye are switched every time the frame is switched. (2) In the cases other than (1), The image for the left eye and the image for the left eye and the image displayed in the previous frame are overwritten.
The backlight is configured so that the lighting state is controlled in accordance with the timing of switching the right eye image and the left eye image.
The optical means has a position and a size corresponding to the first image forming area and the second image forming area, the first polarizing area and the second polarizing area are arranged, and the first polarizing area and the second polarizing area One of the regions constitutes a half-wave plate, or both constitute a quarter-wave plate and their optical axes are orthogonal to each other,
Polarized glasses have a right eyeglass part and a left eyeglass part, and the phase difference state between the right eyeglass part and the left eyeglass part is synchronized with the timing of switching the right eye image and the left eye image part. The present invention relates to a stereoscopic image display device configured to be alternately switched.

  And it is preferable that the light-shielding part is provided in at least one part of the boundary of the 1st polarization area of the optical means and the 2nd polarization area.

  The first image forming area and the second image forming area are each preferably an image forming area composed of 2 to 60 horizontal lines arranged continuously in the vertical direction of the liquid crystal panel.

  Further, the first image forming area and the second image forming area are more preferably image forming areas each including 3 to 30 horizontal lines arranged continuously in the vertical direction of the liquid crystal panel.

The polarized glasses preferably include an infrared sensor, and the liquid crystal display preferably includes an infrared transmitter.
The first image forming area and the second image forming area are synchronized with the timing when the image for the right eye and the image for the left eye are exchanged, and infrared rays are transmitted from the infrared transmission device. The phase difference state can be alternately switched between the eyeglass part and the left eyeglass part.

  The right eyeglass portion and the left eyeglass portion are preferably configured using either a TN liquid crystal element or an STN liquid crystal element.

  Moreover, it is preferable that the right eyeglass part and the left eyeglass part are configured using one of a ferroelectric liquid crystal element and an antiferroelectric liquid crystal element.

  The right eyeglass portion and the left eyeglass portion are any one liquid crystal selected from the group consisting of a VA liquid crystal element, an OCB liquid crystal element, a homogeneous ECB liquid crystal element, and a HAN ECB liquid crystal element. It is preferable that the device is configured using an element.

  In addition, the frame switching in the liquid crystal display is preferably performed at a cycle of 120 Hz or more.

  In particular, the frame switching in the liquid crystal display is more preferably performed at a cycle of 240 Hz or more.

  According to the first aspect of the present invention, the image for the right eye and the image for the left eye are displayed simultaneously on one screen, and the area for forming the image for the right eye and the image for the left eye is switched every frame switching. However, only the image light for the right eye can be observed with the right eye, and only the image light for the left eye can be observed with the left eye. Therefore, the observer can always recognize these right-eye image light and left-eye image light as a stereoscopic image.

In the conventional stereoscopic image display device, the resolution is lowered, for example, the vertical resolution is halved. On the other hand, it is possible to display at the full resolution without reducing the resolution at all.
Moreover, since the images for the right eye and the left eye are always displayed, it is possible to reduce the fatigue of the viewer. In addition, there is also an effect of preventing a sense of incongruity in stereoscopic viewing due to a shift in the left and right images that occurs in the case of a stereoscopic image that is moving violently.

  Then, the area for forming the right-eye and left-eye images is composed of a plurality of horizontal lines, and further, it is possible to provide a light-shielding portion at the boundary of each area. When observed from a certain viewing angle position, crosstalk that a part of the image for the right eye passes through the half-wave plate for the left eye and reaches the left eye of the observer is reduced.

  Furthermore, even if the response speed of the liquid crystal element used for a required liquid crystal display and polarized glasses is slow, it can be used. On the other hand, when the response speed of the liquid crystal element is fast, it is possible to obtain a stereoscopic image display with a much higher luminance than in the past.

It is a typical disassembled perspective view explaining the principal part structure of the three-dimensional image display apparatus of this Embodiment. It is a typical top view of the liquid crystal panel which comprises the three-dimensional image display apparatus of this Embodiment. It is a schematic sectional drawing of the phase difference plate used in the three-dimensional image display apparatus of this Embodiment. It is typical sectional drawing of the three-dimensional image display apparatus of this Embodiment. It is a typical disassembled perspective view explaining the structure of the spectacles part for right eyes and the spectacles part for left eyes of the polarized glasses of this Embodiment. It is a typical disassembled perspective view explaining another structure of the glasses part for right eyes and the glasses part for left eyes of the polarized glasses of this Embodiment. It is a figure explaining the method of making an observer recognize a stereo image using the stereo image display apparatus of this Embodiment. It is a figure explaining the display method of a general liquid crystal display. It is a figure explaining operation | movement of the stereo image display apparatus of this Embodiment.

  FIG. 1 is a schematic exploded perspective view for explaining a main configuration of a stereoscopic image display apparatus 1 according to the present embodiment. As shown in FIG. 1, the stereoscopic image display device 1 includes a backlight 2, a liquid crystal display 3, and a phase difference plate 8 that is an optical means in this order, and these are accommodated in a casing (not shown). . The stereoscopic image display apparatus 1 includes polarizing glasses 10 that are used by an observer who wants to observe a stereoscopic image, and observes the image on the screen from the front side of the phase difference plate 8. At this time, as will be described later, the casing of the liquid crystal display 3 is provided with an infrared transmission device 9, and the polarizing glasses 10 are provided with an infrared sensor 11 for detecting infrared rays emitted from the infrared transmission device 9. .

  The backlight 2 is arranged on the farthest side of the stereoscopic image display device 1 as viewed from the observer, and is displaying an image on the stereoscopic image display device 1 (hereinafter referred to as “usage state of the stereoscopic image display device 1”). In this case, white non-polarized light is emitted toward one surface of the polarizing plate 5 so as to have a uniform amount of light. In the present embodiment, a surface light source is used for the backlight 2, but a combination of a point light source such as an LED and a condenser lens may be used instead of the surface light source. An example of this condensing lens is a Fresnel lens sheet. The Fresnel lens sheet has a concentric concave and convex lens surface on one side surface and can emit light incident from the central focal point on the back side to the front side as substantially parallel light.

  FIG. 2 is a schematic plan view of the liquid crystal panel 6 constituting the stereoscopic image display device 1 of the present embodiment. As shown in FIG. 2, the liquid crystal display 3 includes a pair of liquid crystal panels 6 each having a plurality of horizontal lines 23 in which pixels (not shown) are arranged in the horizontal direction. The polarizing plate 5 and the polarizing plate 7 are sandwiched.

  The polarizing plate 5 is disposed on the backlight 2 side of the liquid crystal panel 6 in the liquid crystal display 3. The polarizing plate 5 has a transmission axis and an absorption axis perpendicular to the transmission axis. When non-polarized light emitted from the backlight 2 is incident, the polarizing plate 5 transmits light having a polarization axis parallel to the transmission axis direction. The light of the polarization axis parallel to the absorption axis direction is blocked. Here, the direction of the polarization axis is the vibration direction of the electric field in the light, and the direction of the transmission axis in the polarizing plate 5 is as shown by the arrow in FIG. Direction parallel to the horizontal direction.

  The liquid crystal panel 6 is configured by sandwiching liquid crystal with a glass substrate on which a transparent electrode made of ITO (Indium Tin Oxide) or the like is disposed. A liquid crystal panel in a TN (Twisted Nematic) mode, an IPS (In-Plane-Switching) mode, or a VA (Vertical Alignment) mode can be used. All of these change the orientation of the liquid crystal according to the applied voltage, and in combination with the action of the polarizing plates 5 and 7 disposed on both sides of the liquid crystal panel 6, the amount of transmitted light can be adjusted.

  The liquid crystal panel 6 is an important constituent member that is responsible for image formation in the stereoscopic image display device 1, and displays a right-eye image and a left-eye image simultaneously on one screen. The configuration and functions related to image display will be described below.

  First, in the image display portion of the liquid crystal panel 6, a first image forming area 21 and a second image forming area 22 are provided that are partitioned in the horizontal direction. The first image forming area 21 and the second image forming area 22 are areas having the same area obtained by dividing the liquid crystal panel 6 in the horizontal direction as shown in FIG. The second image forming regions 22 are alternately arranged in the vertical direction.

  As shown in FIG. 2, the first image forming area 21 and the second image forming area 22 of the liquid crystal panel 6 are each composed of a plurality of horizontal lines 23 arranged continuously in the vertical direction. In the liquid crystal panel 6 shown in FIG. 2, the first image forming area 21 and the second image forming area 22 are each composed of three horizontal lines 23 arranged in succession.

  As a result, the first horizontal line to the third horizontal line at the top of the liquid crystal panel 6 are bundled to form the first image forming region 21, and the fourth horizontal line to the sixth horizontal line are formed. The second image forming area 22 is bundled to form a first image forming area 21 from the seventh horizontal line to the ninth horizontal line, and the twelfth line from the tenth horizontal line is formed. Up to horizontal lines are bundled to form a second image forming area 22, and three horizontal lines 23 are sequentially bundled, and a plurality of first image forming areas 21 and second image forming areas are alternately arranged on the liquid crystal panel 6. 22 is arranged.

  At this time, the number of horizontal lines 23 constituting the first image forming area 21 and the second image forming area 22 is not limited to three, and can be constituted by a plurality of lines. For example, the number of horizontal lines 23 constituting the first image forming area 21 and the second image forming area 22 can be set to ten.

  In that case, the first horizontal line to the 10th horizontal line at the top of the liquid crystal panel 6 are bundled to form the first image forming area 21, and the 11th horizontal line to the 20th horizontal line are formed. The second image forming area 22 is bundled to form the first image forming area 21 by bundling from the 21st horizontal line to the 30th horizontal line, and the 40th line from the 31st horizontal line. Up to horizontal lines are bundled to form a second image forming area 22, ten horizontal lines 23 are sequentially bundled, and a plurality of first image forming areas 21 and second image forming areas are alternately arranged on the liquid crystal panel 6. 22 is arranged.

  That is, as will be described in detail later, the number of horizontal lines 23 constituting the first image forming region 21 and the second image forming region 22 is selected from the viewpoint of reducing crosstalk and widening the viewing angle of the liquid crystal display 3. Is done.

Then, on the liquid crystal panel 6 of the liquid crystal display 3 of the stereoscopic image display device 1, a right eye image and a left eye image are respectively displayed in the first image forming area 21 and the second image forming area 22 of one frame image to be displayed. The image for right eye and the image for left eye are exchanged between the first image forming area 21 and the second image forming area 22 in accordance with the following method (1) or (2).
(1) The right-eye image and the left-eye image are switched every time the frame is switched.
(2) In cases other than (1), at the time of frame switching, one of the replacement of the right-eye image and the left-eye image and the overwriting of the image displayed in the immediately preceding frame is performed (not replaced) In the case where each keeps the right eye image and the left eye image).

  Although not shown in FIG. 1, an outer frame 25 is disposed on the periphery of the liquid crystal panel 6, and the first image forming region 21 and the second image forming region 22 in the liquid crystal panel 6 are located in the outer frame 25. Supported.

  As described above, when the stereoscopic image display device 1 is in use, each of the first image forming area 21 and the second image forming area 22 of the liquid crystal panel 6 displays, for example, a right-eye image when a certain frame image is displayed. And an image for the left eye is generated. At this time, when the light transmitted through the polarizing plate 5 enters the first image forming area 21 and the second image forming area 22 of the liquid crystal panel 6, the transmitted light of the first image forming area 21 is the image light of the right-eye image (hereinafter referred to as the image light). , Abbreviated as “right eye image light”), and the transmitted light of the second image forming area 22 becomes image light of the left eye image (hereinafter abbreviated as “left eye image light”). When the switching is performed corresponding to the switching of the frames, a left-eye image and a right-eye image are generated in the first image forming area 21 and the second image forming area 22, respectively.

  Note that the right-eye image light transmitted through the first image forming area 21 and the left-eye image light transmitted through the second image forming area 22 in the case of displaying one frame image described above are transmitted through the polarizing plate 7 described later. Thus, linearly polarized light having a polarization axis in a specific direction is obtained. Here, the polarization axes in specific directions may be the same as each other. In the example shown in FIG. 1, the polarization axes are both the same as the direction of the transmission axis in the polarizing plate 7 described later.

  The polarizing plate 7 is disposed on the viewer side in the liquid crystal display 3. When the right-eye image light that has passed through the first image forming region 21 and the left-eye image light that has passed through the second image forming region 22 are incident on the polarizing plate 7, the polarization axis is transmitted. Light that is parallel to the axis is transmitted, and light whose polarization axis is parallel to the absorption axis (perpendicular to the transmission axis) is blocked. Here, the direction of the transmission axis in the polarizing plate 7 is a direction perpendicular to the horizontal direction when the observer views the stereoscopic image display device 1 as indicated by an arrow in FIG.

  The phase difference plate 8 has a first polarizing region 31 and a second polarizing region 32. The positions and sizes of the first polarizing region 31 and the second polarizing region 32 on the retardation plate 8 are the same as the positions of the first image forming region 21 and the second image forming region 22 of the liquid crystal panel 6 as shown in FIG. And corresponds to the size.

  As described above, in the liquid crystal panel 6 constituting the stereoscopic image display device 1 according to the present embodiment shown in FIG. 2, among all the horizontal lines related to the image display of the liquid crystal panel 6, sequentially from the top in the vertical direction. The three horizontal lines 23 are bundled to form one set for convenience, and the first image forming area 21 and the second image forming area 22 having the same area corresponding to each of the bundled horizontal line sets. And are provided. Therefore, the positions and sizes of the first polarizing region 31 and the second polarizing region 32 in the retardation plate 8 are a set of three horizontal lines bundled in the liquid crystal panel 6 as shown in FIG. This corresponds to the positions and sizes of the one image forming area 21 and the second image forming area 22.

  Therefore, in the usage state of the stereoscopic image display device 1, when one frame image is displayed, the right-eye image light transmitted through the first image forming region 21 in the above case is incident on the first polarizing region 31, The left-eye image light transmitted through the second image forming region 22 in the above case is incident on the second polarizing region 32. When the switching is performed corresponding to the switching of the frames, the left-eye image light transmitted through the first image forming area 21 is incident on the first polarizing area 31 and the second polarizing area 32 is The right-eye image light that has passed through the second image forming region 22 enters.

  In the stereoscopic image display device 1 according to the present embodiment, the first image forming area 21 and the second image forming area 22 correspond to each one of all the horizontal lines related to the image display of the liquid crystal panel 6. It is also possible to provide. In that case, the first polarizing region 31 and the phase difference plate 8 also correspond to the positions and sizes of the first image forming region 21 and the second image forming region 22 corresponding to the horizontal lines 23 of the liquid crystal panel 6. A second polarizing region 32 is formed.

  Then, for example, an image for the right eye and an image for the left eye are respectively provided in the first image forming area 21 corresponding to the horizontal odd line of the one frame image to be displayed and the second image forming area 22 corresponding to the horizontal even line. Each time the frame is switched, the horizontal lines on which the right-eye image and the left-eye image are displayed are alternately switched, and a frame image in which the right-eye image and the left-eye image are interlaced is displayed. .

However, in that case, the problem of crosstalk becomes significant.
That is, the observer 50 may observe a stereoscopic image on the stereoscopic image display device 1 with a certain viewing angle from the central vertical direction of the liquid crystal display 3 constituting the screen of the stereoscopic image display device 1. Originally, at the time of displaying one frame image, only the right eye image light transmitted through the first image forming region 21 of the liquid crystal panel 6 in the above case is incident on the first polarizing region 31 of the phase difference plate 8. While it is necessary that only the image light for the left eye that has passed through the second image forming region 22 is incident on the second polarizing region 32, the first image of the liquid crystal panel 6 is obtained when the viewing angle is increased. Part of the right-eye image light that has passed through the formation region 21 may enter the second polarizing region 32 where only the left-eye image light should enter, and may reach the left eye of the observer 50 together with the left-eye image light. .

Such type of crosstalk is caused by the fact that the first polarizing region 31 and the second polarizing region 32 having different phase difference characteristics are provided adjacent to each other in the retardation plate 8.
That is, as described above, in the liquid crystal panel 6 of the stereoscopic image display device 1 according to the present embodiment, for example, three horizontal lines 23 are bundled sequentially from the top in the vertical direction to form one set for convenience. The first image forming region 21 and the second image forming region 22 having the same area are provided so as to correspond to the bundled horizontal line groups. Correspondingly, the first polarizing region 31 and the second polarizing region 32 of the phase difference plate 8 are provided so as to be adjacent to each other, and the crosstalk is a viewing angle that is the vertical direction of the screen of the stereoscopic image display device 1. This is likely to occur when the observer 50 observes the image on the screen.

  This type of crosstalk occurs in the boundary region between the first polarizing region 31 and the second polarizing region 32 that are adjacent to each other on the retardation plate 8. Therefore, in order to reduce this, first of all, it is effective to reduce the boundary region between the first polarizing region 31 and the adjacent second polarizing region 32 in the retardation plate 8.

  For example, when the liquid crystal panel 6 has 1080 horizontal lines corresponding to the full HD (Full High Definition) specification, the first image forming region 21 and the second image forming area 21 correspond to each of all the horizontal lines as described above. If the image forming area 22 is provided, 540 of them are alternately provided. In the retardation plate 8, 540 first polarizing regions 31 and second polarizing regions 32 are provided so as to correspond to the positions and sizes of the first image forming region 21 and the second image forming region 22 of the liquid crystal panel 6. Will have. As a result, 1079 boundary regions between the first polarizing region 31 and the adjacent second polarizing region 32 are formed.

  When the observer 50 observes the screen of the stereoscopic image display device 1 with a certain viewing angle, crosstalk occurs in each of the boundary regions, and the intensity corresponds to each of all the horizontal lines as described above. When the first image forming area 21 and the second image forming area 22 are provided, the height is highest.

  On the other hand, as illustrated in FIGS. 1 and 2, when the first image forming area 21 and the second image forming area 22 of the liquid crystal panel 6 of the present embodiment are configured by a plurality of horizontal lines 23. In the retardation plate 8, the first polarizing region 31 and the second polarizing region 32 are formed corresponding to the positions and sizes of the first image forming region 21 and the second image forming region 22 of the liquid crystal panel 6. Therefore, their area increases according to the number of horizontal lines 23 bundled together. As a result, in the phase difference plate 8, the boundary region between the first polarizing region 31 and the adjacent second polarizing region 32 can be reduced.

  That is, since the boundary region between the first polarizing region 31 that generates crosstalk and the adjacent second polarizing region 32 is reduced, the stereoscopic image display device 1 of the present embodiment has a certain viewing angle and the viewer 50 has a certain viewing angle. When a stereoscopic image is to be observed, the occurrence of crosstalk is reduced as a whole of the stereoscopic image display device 1. Therefore, as the number of horizontal lines 23 bundled together to form the first image forming area 21 and the second image forming area 22 of the liquid crystal panel 6 increases, the crosstalk is suppressed, and the observer 50 can It becomes difficult to feel.

Therefore, in the stereoscopic image display device 1 of the present embodiment, crosstalk is reduced, the observable viewing angle is expanded, and the viewing angle characteristics are improved.
From the above, from the viewpoint of reducing crosstalk, the number of horizontal lines 23 bundled together to form the first image forming area 21 and the second image forming area 22 of the liquid crystal panel 6 is larger. Is preferred.

  In addition, a light shielding portion 24 can be provided in the boundary region between the first polarizing region 31 and the second polarizing region 32 on the surface of the retardation plate 8 facing the liquid crystal display 3. It is preferable that the light shielding portion 24 has a band shape and is disposed in a boundary region between the first polarizing region 31 and the second polarizing region 32. FIG. 3 is a schematic cross-sectional view of the phase difference plate 8 used in the stereoscopic image display device 1 of the present embodiment.

  By providing such a light shielding portion 24, among the right-eye or left-eye image light to be incident on the second polarization region 32 adjacent to the first polarization region 31 of the phase difference plate 8, the first light adjacent to the boundary beyond the boundary. It becomes possible to absorb and block the image light incident on the one polarization region 31.

  Similarly, by providing the light-shielding portion 24, the image light for the right eye or the left eye to be incident on the first polarizing region 31 adjacent to the second polarizing region 32 of the retardation plate 8 is adjacent beyond the boundary. It becomes possible to absorb and block the image light incident on the second polarizing region 32 to be performed. As described above, by providing the light shielding portion on the phase difference plate 8, it is possible to make it difficult for crosstalk to occur in the right-eye image light and the left-eye image light emitted from the stereoscopic image display device 1.

  The light shielding portion 24 is preferably formed of, for example, a binder resin in which a filler component is dispersed. As the filler component, metal particles and oxides thereof, or pigments and dyes are used. The color tone of the filler component is preferably black with respect to the right-eye image light and the left-eye image light. The binder resin for dispersing or dissolving the pigment and dye may be a known resin such as acrylic resin, urethane resin, polyester, novolac resin, polyimide, epoxy resin, vinyl chloride / vinyl acetate copolymer, nitrocellulose, or a combination thereof. Can be used.

FIG. 4 is a schematic cross-sectional view of the stereoscopic image display device 1 of the present embodiment.
In the three-dimensional image display device 1 of the present embodiment, the liquid crystal display 3 and the phase difference plate 8 are stacked. As an example, the surface of the phase difference plate 8 on which the light shielding portion 24 is provided is the liquid crystal display. 3 is arranged so as to face 3.

  Here, as shown in FIG. 4, the liquid crystal display 3 is opened in a state where the polarizing plate 5 and the polarizing plate 7 are respectively attached to both surfaces of the liquid crystal panel 6 in which the outer frame 25 is arranged on the periphery in advance. It is attached to the case 26. The surface on which the polarizing plate 7 is attached is exposed to the outside from the open surface of the housing 26. The casing 26 is made of, for example, plastic or stainless steel, and the backlight 2 is fixed to the inside of the surface facing the open surface.

  In the stereoscopic image display device 1, since the retardation plate 8 and the liquid crystal display 3 are arranged as described above, the surface of the liquid crystal display 3 on which the polarizing plate 7 is attached is the light shielding portion 24 in the retardation plate 8. It faces the surface where Then, the liquid crystal display 3 and the phase difference plate are arranged so that the first polarization region 31 and the second polarization region 32 of the phase difference plate 8 face the first image generation region 21 and the second image generation region 22 of the liquid crystal panel 6, respectively. 8 are positioned with respect to each other in the surface direction, and are configured to abut the mutually facing surfaces of the liquid crystal display 3 and the phase difference plate 8.

  The outer frame 25 corresponding to the peripheral edge of the liquid crystal panel 6 and the side surface of the phase difference plate 8 are bonded together with an adhesive 27. As a result, crosstalk is less likely to occur when the stereoscopic image display device 1 is used. In addition, you may attach a diffuser plate, an antireflection film, etc. further to the surface of the phase difference plate 8 exposed to the outside.

  However, the light shielding unit 24 functions in the form of shielding a part of the image light that passes through the liquid crystal display 3 and reaches the eyes of the observer 50. That is, it is effective in reducing crosstalk, but the screen brightness in the image display of the stereoscopic image display device 1 is lowered.

  For example, as described above, when the first image forming area 21 and the second image forming area 22 are provided so as to correspond to all horizontal lines, the second polarizing area 32 adjacent to the first polarizing area 31 The boundary area is the largest, and the number of strip-shaped light shielding portions 24 that need to be formed for each boundary area is the largest. As a result, the influence of the decrease in luminance due to the formation of the light shielding portion 24 is the greatest.

  Therefore, although it is effective to reduce the crosstalk by forming the light shielding portions 24, it is preferable to reduce the number of formations as much as possible.

  In that case, as shown in FIG. 1 and FIG. 2, when the number of the horizontal lines 23 constituting the first image forming area 21 and the second image forming area 22 of the liquid crystal panel 6 is composed of a plurality, the phase difference In the plate 8, the first polarizing region 31 and the second polarizing region 32 are formed corresponding to the positions and sizes of the first image forming region 21 and the second image forming region 22 of the liquid crystal panel 6. The area increases in accordance with the number of horizontal lines 23 bundled together in the liquid crystal panel 6. Therefore, in the phase difference plate 8, the boundary region between the first polarizing region 31 and the second polarizing region 32 adjacent to the first polarizing region 31 can be reduced, and consequently, the light shielding portions 24 formed in the boundary region are reduced.

  As a result, when a stereoscopic image is observed with the stereoscopic image display device 1 of the present embodiment, the observer 50 bundles the liquid crystal panel 6 to form the first image forming area 21 and the second image forming area 22. As the number of horizontal lines 23 to be paired increases, a decrease in screen luminance due to the light shielding unit 24 is suppressed, and the viewer 50 can obtain a high-luminance stereoscopic image.

  From the above results, from the viewpoint of reducing crosstalk and suppressing reduction in screen luminance in the stereoscopic image display device 1, the stereoscopic image display device 1 is bundled to form the first image forming region 21 and the second image forming region 22 of the liquid crystal panel 6. It can be seen that the number of horizontal lines 23 in one set is preferably plural, and that the number of horizontal lines 23 in one set is preferably increased.

  Then, the liquid crystal panel 6 has a larger size corresponding to the position and size of the plurality of horizontal lines 23 that are bundled together to form the first image forming area 21 and the second image forming area 22 of the liquid crystal panel 6. It is preferable to form the first polarizing region 31 and the second polarizing region 32 of the phase difference plate 8.

  However, increasing the number of horizontal lines 23 that are bundled together to form the first image forming area 21 and the second image forming area 22 of the liquid crystal panel 6 is unlimited. This causes the same problem as known in stereoscopic image display devices. That is, in the conventional shutter glasses type stereoscopic image display device, flicker that is a flicker of the display image, a decrease in luminance on the display screen, and a time difference between the images that appear on the left and right eyes occur, which is natural for the observer. There is a problem that a simple image cannot be obtained.

  Therefore, in the stereoscopic image display device 1 according to the present embodiment, from the viewpoints of reducing crosstalk and suppressing the reduction in screen luminance, and suppressing the flicker and enabling a natural stereoscopic image for the observer 50. It is preferable to select the number of horizontal lines 23 that are bundled together to form the first image forming area 21 and the second image forming area 22 of the liquid crystal panel 6, and correspondingly the phase difference It is preferable to form the first polarizing region 31 and the second polarizing region 32 of the plate 8.

  As a result of intensive studies, the first image forming area 21 and the second image forming area 22 of the liquid crystal panel 6 are respectively arranged in two to 60 horizontal lines that are continuously arranged in the vertical direction of the liquid crystal panel 6. It was found that an image forming area consisting of 23 is preferable.

  Further, each of the first image forming area 21 and the second image forming area 22 of the liquid crystal panel 6 is an image forming area composed of three to thirty horizontal lines 23 arranged continuously in the vertical direction of the liquid crystal panel 6. It is more preferable that the image forming area is composed of 5 to 15 horizontal lines 23. Of course, it is preferable to form the first polarizing region 31 and the second polarizing region 32 of the phase difference plate 8 at positions and sizes corresponding thereto.

  Next, as shown in FIG. 1, right-eye or left-eye image light is incident on the first polarizing region 31 of the retardation plate 8 as linearly polarized light whose polarization axis is perpendicular to the horizontal direction. However, the incident image light for the right eye or the left eye is emitted as counterclockwise circularly polarized light. The second polarization region 32 emits the incident right-eye or left-eye image light as clockwise circularly polarized light.

  Accordingly, the right-eye or left-eye image light transmitted through the first polarizing region 31 and the corresponding left-eye or right-eye image light transmitted through the second polarizing region 32 are indicated by arrows in FIG. , The rotation directions become circularly polarized light in opposite directions. In addition, the arrow in the phase difference plate 8 in FIG. 1 schematically shows the rotation direction of the polarized light that has passed through the phase difference plate 8.

  The first polarizing region 31 constituting the phase difference plate 8 is a quarter wavelength plate whose optical axis is 45 degrees from the horizontal direction to the upper right, and the second polarizing region 32 has the optical axis horizontal. A quarter-wave plate that is 45 degrees in the upper left direction is used. Here, the optical axis refers to one of a fast axis and a slow axis when light passes through the first polarizing region 31 or the second polarizing region 32.

  As described above, the retardation plate is not only composed of quarter-wave plates whose optical axes are orthogonal to each other, but a half-wave plate whose optical axis is in the 45 ° upper right direction from the horizontal direction. It is also possible to use a retardation plate in which a single polarizing region is used and a member such as glass or resin having substantially no retardation is used as the second polarizing region.

  In that case, the linearly polarized light or the optical axis rotated by 90 degrees of the optical axis of the image light emitted from the phase difference plate is rotated according to the area of the phase difference plate to be transmitted with respect to the incident image light that is linearly polarized light. The linearly polarized light is left untouched. Therefore, for these image lights, as will be described later, the right eyeglass part and the left eyeglass part of the polarizing glasses are appropriately configured from the liquid crystal element and the polarizing plate described above to select transmission and blocking, respectively. Thus, a stereoscopic image display apparatus having the same function as described above can be configured.

  In addition, as described above, the stereoscopic image display device 1 has the right-eye image light transmitted through the first polarizing region 31 and the second polarizing region 32 of the retardation plate 8 and the observer side of the retardation plate 8 and the right-eye image light. A diffusion plate that diffuses the image light for the left eye in at least one of the horizontal direction and the vertical direction may be provided. For such a diffuser plate, for example, a lenticular lens sheet in which a plurality of cylindrically shaped convex lenses (cylindrical lenses) extending in the horizontal direction or the vertical direction is used, or a lens array sheet in which a plurality of convex lenses are arranged in a planar shape are used. It is done.

  When a stereoscopic image is observed by the stereoscopic image display device 1, the observer 50 observes the right eye image light and the left eye image light projected from the stereoscopic image display device 1 through the polarizing glasses 10. In the polarizing glasses 10, a right eye glasses unit 41 is disposed at a position corresponding to the right eye side of the observer 50, and a left eye glasses unit 42 is disposed at a position corresponding to the left eye side.

  The right eyeglass part 41 and the left eyeglass part 42 can be electrically driven, and are composed of TN mode liquid crystal elements or ferroelectric liquid crystal elements having different initial alignment states of liquid crystals. These liquid crystal element driving devices (not shown) are fixed to the frame of the polarizing glasses 10.

  Note that the infrared sensor 11 is provided on the frame of the polarizing glasses 10 as described above. Then, infrared rays transmitted from the infrared transmission device 9 provided in the liquid crystal display 3 are sensed in synchronization with the switching of the image areas by switching the frames in the liquid crystal display 3, and the right eye glasses unit 41 and the left eye glasses unit 42 are detected. Is instructed to drive the above-described liquid crystal element.

  That is, in the liquid crystal display 3 and the polarizing glasses 10, the infrared transmission device 9 provided in the liquid crystal display 3 transmits infrared rays that function as a synchronization signal in synchronization with frame switching in the liquid crystal display 3. The transmitted infrared rays are received by the infrared sensor 11 of the polarizing glasses 10, and the polarized glasses 10 sense the change of the image area as the frame is switched on the liquid crystal display 3 using this as a synchronization signal. As a result, driving of the above-described liquid crystal elements constituting the right-eye glasses unit 41 and the left-eye glasses unit 42 is started so as to correspond to the switching of the image regions accompanying the frame switching.

  In the three-dimensional image display device 1 of the present embodiment, the liquid crystal elements constituting the right eyeglass part 41 and the left eyeglass part 42 in the polarizing glasses 10 are exchanged as the frame is switched in the liquid crystal display 3. The synchronization with the driving of the liquid crystal display 3 is configured to be realized by a system including the infrared transmission device 9 of the liquid crystal display 3 and the infrared sensor 11 of the polarizing glasses 10.

  However, in addition to the wireless system using infrared rays, the driving circuit of the liquid crystal display 3 and the driving devices of the right eyeglass unit 41 and the left eyeglass unit 42 of the polarizing glasses 10 are wired to connect the liquid crystal display 3. It is also possible to control the driving of the right eyeglass unit 41 and the left eyeglass unit 42 by a command from the drive circuit.

The right eyeglass part 41 and the left eyeglass part 42 constituting the polarized glasses 10 are configured using a TN liquid crystal element or a ferroelectric liquid crystal element that can be electrically driven.
The right-eye glasses 41 and the left-eye glasses 42 constituting the polarizing glasses 10 are configured using an electrically driven STN (Super Twisted Nematic) type liquid crystal element or antiferroelectric liquid crystal element. Is also possible. While the twist angle of the liquid crystal is about 90 degrees in the TN liquid crystal element, the twist angle of the liquid crystal is increased to about 270 degrees, and the steepness of the liquid crystal rising operation is improved. It is a liquid crystal element. The antiferroelectric liquid crystal element is a liquid crystal element that uses an antiferroelectric phase liquid crystal and can operate at a very high speed.

  Further, the right eyeglass part 41 and the left eyeglass part 42 constituting the polarizing glasses 10 are electrically driven ECB (Electrically Controlled Birefringence) type liquid crystal element, VA (Vertical Alignment) type liquid crystal element or OCB (Optically). It is also possible to use a Compensated Bend) type liquid crystal element. In an ECB type liquid crystal element, a homogeneous ECB type liquid crystal element in which the initial alignment of the liquid crystal is homogeneous alignment and a liquid crystal having negative dielectric anisotropy and a HAN (Hybrid- It is also possible to use an aligned nematic) type liquid crystal element.

FIG. 5 is a schematic exploded perspective view illustrating a configuration in the case where the right eyeglass part 41 and the left eyeglass part 42 are made of TN mode liquid crystal elements.
The right eyeglass part 41 and the left eyeglass part 42 constituting the polarizing glasses 10 respectively include quarter wavelength plates 43a and 43b, TN liquid crystal cells 44a and 44b, and polarizing plates 45a and 45b in this order, These are fixed to the frame together with a drive device (not shown).

  At this time, in the polarizing glasses 10 of the present embodiment, when the observer 50 in use wears the polarizing glasses 10 and faces the liquid crystal display 3, the quarter-wave plate 43a of the right-eye glasses unit 41 The optical axis is in the direction of 45 degrees on the upper right from the horizontal direction (upper right 45 degrees on the paper surface), and the transmission axis of the polarizing plate 45a is in the direction parallel to the horizontal direction. In the TN liquid crystal cell 44a, the initial alignment of the liquid crystal is formed so that the outgoing light is rotated 90 degrees counterclockwise with respect to the linearly polarized light that is incident when no voltage is applied. At this time, when the liquid crystal is driven by the above-described driving device and the liquid crystal changes its orientation and becomes a so-called ON state, the optical rotation in such a TN liquid crystal cell 44a is lost, and the incident light is converted into linearly polarized light with the same characteristics. Emitted.

  In addition, the optical axis of the quarter-wave plate 43b of the left eyeglass unit 42 is in the direction of 45 degrees on the upper left side (45 degrees on the upper left side of the drawing) from the horizontal direction, and the transmission axis of the polarizing plate 45b is parallel to the horizontal direction. It is in. In the TN liquid crystal cell 44b, the initial alignment of the liquid crystal is formed so that the outgoing light is rotated 90 degrees clockwise with respect to the linearly polarized light that is incident when no voltage is applied. At this time, when the liquid crystal is driven by the above-described driving device and the liquid crystal changes its orientation and becomes a so-called ON state, the optical rotation in such a TN liquid crystal cell 44a is lost, and the incident light is converted into linearly polarized light with the same characteristics. Emitted.

  FIG. 6 is a schematic exploded perspective view for explaining the configuration of polarized glasses when the right eyeglass portion 41 ′ and the left eyeglass portion 42 ′ are made of a ferroelectric liquid crystal element. The ferroelectric liquid crystal elements constituting the right eyeglass part 41 'and the left eyeglass part 42' are surface-stabilized ferroelectric liquid crystal elements. The surface-stabilized ferroelectric liquid crystal device has a fast response speed, and when used in the right eyeglass part 41 ′ and the left eyeglass part 42 ′ of the polarizing glasses 10, the orientation of the liquid crystal can be changed quickly and smoothly with driving. It is preferable.

  Another example of the polarized glasses is a right-eye glasses unit 41 ′ and a left-eye glasses unit 42 ′, which are quarter wave plates 43a ′ and 43b ′, ferroelectric liquid crystal cells 44a ′ and 44b ′, respectively. Polarizing plates 45a ′ and 45b ′ are provided in this order, and these are fixed to the frame together with a driving device (not shown).

  At this time, in the polarizing glasses 10 ′ of the present embodiment, when the observer 50 in use wears the polarizing glasses and faces the liquid crystal display 3, the ¼ wavelength plate 43 a of the right eyeglass portion 41 ′. The optical axis of 'is in the direction of 45 degrees to the upper right from the horizontal direction (45 degrees to the upper right of the paper surface), and the transmission axis of the polarizing plate 45a' is in the direction parallel to the horizontal direction.

  In the ferroelectric liquid crystal cell 44a ′, there are two alignment states, that is, the alignment state of the liquid crystal that is emitted with the same characteristics with respect to the incident linearly polarized light and the alignment state that can be rotated 90 degrees counterclockwise and emitted. The initial alignment of the liquid crystal is formed so that a stable alignment state can be taken. Such two stable alignment states can be selected by applying a voltage of an appropriate polarity by the driving device described above.

In addition, the optical axis of the quarter-wave plate 43b ′ of the eyeglass portion 42 ′ for the left eye is in the direction from the horizontal direction to the upper left 45 degrees (upper left 45 degrees in the drawing), and the transmission axis of the polarizing plate 45 b ′ is the horizontal direction. In parallel directions.
In the ferroelectric liquid crystal cell 44b ′, there are two alignment states, that is, the alignment state of the liquid crystal that is emitted with the same characteristics with respect to the incident linearly polarized light, and the alignment state that can be rotated 90 degrees clockwise and emitted. The initial alignment of the liquid crystal is formed so that a stable alignment state can be taken. The selection of the two stable alignment states can be made as desired by applying a voltage of an appropriate polarity by the driving device described above.

  The configuration of the stereoscopic image display device 1 according to the present embodiment is as described above. Next, using the stereoscopic image display device 1 according to the present embodiment, from the right-eye image light and the left-eye image light, the observer 50 Next, a method for causing the image to be recognized as a stereoscopic image will be described.

  FIG. 7 is a diagram for explaining a method for allowing an observer to recognize a stereoscopic image using the stereoscopic image display device 1 of the present embodiment. FIG. 7A is a diagram for explaining a method for causing an observer to recognize a single frame image, and FIG. 7B shows a frame image after being switched by frame switching. It is a figure explaining the method to make.

  When the observer 50 observes a stereoscopic image with the stereoscopic image display device 1, as described above, the first image forming area 21 and the second image forming area 22 of the liquid crystal panel 6 display a certain frame image. First, a right-eye image and a left-eye image are formed correspondingly.

  7A, the right-eye image light that has passed through the first image forming area 21 and the left-eye image light that has passed through the second image forming area 22 are transmitted through the polarizing plate 7. , Linearly polarized light having a polarization axis in a direction perpendicular to the horizontal direction.

Then, although it is incident on the phase difference plate 8, the right-eye image light is incident on the first polarization region 31 of the phase difference plate 8. Then, as indicated by an arrow in FIG. 7A, the incident right-eye image light is emitted as counterclockwise circularly polarized light. In the second polarization region 32, the incident left-eye image light is emitted as clockwise circularly polarized light as indicated by an arrow in FIG.
Next, the right-eye image light and the left-eye image light thus obtained are incident on the polarizing glasses 10 worn by the observer 50.

  When the polarizing glasses 10 constitute the right eyeglass portion 41 and the left eyeglass portion 42 using a TN mode liquid crystal element, an appropriate voltage is applied to the TN liquid crystal cell to cancel the twisted state of the liquid crystal, so-called A state in which the ON state is formed is realized. In this case, the image light for the right eye that has been counterclockwise circularly polarized light passes through the quarter-wave plate 43a included in the right-eye glasses 41 and is parallel to the horizontal direction, as indicated by an arrow in FIG. It is rotated by the linearly polarized light, passes through the TN liquid crystal cell 44a and the polarizing plate 45a in the ON state as they are, and reaches the right eye of the observer 50.

  On the other hand, when the right-eye image light that is counterclockwise circularly polarized light is incident on the left-eye glasses unit 42, the quarter-wave plate 43b included in the left-eye glasses unit 42 is provided as shown by an arrow in FIG. The light is transmitted and returned to the linearly polarized light perpendicular to the horizontal direction, passes through the TN liquid crystal cell 44b in the ON state, and enters the polarizing plate 45b, but cannot pass through the polarizing plate 45b and is blocked. It does not reach the left eye.

  Further, the image light for the left eye, which has been clockwise circularly polarized light, is transmitted through the quarter wavelength plate 43b included in the left eyeglass unit 42 and converted into linearly polarized light parallel to the horizontal direction, and is turned on. 44b and the polarizing plate 45b are transmitted as they are and reach the left eye of the observer 50.

  On the other hand, when left-eye image light that is clockwise circularly polarized light is incident on the right-eye glasses unit 41, the light is transmitted through the quarter-wave plate 43a included in the right-eye glasses unit 41 to return to linearly polarized light perpendicular to the horizontal direction. Then, the light passes through the TN liquid crystal cell 44a in the ON state and enters the polarizing plate 45a, but cannot pass therethrough, is blocked, and does not reach the right eye of the observer 50.

  Thus, within the range in which the right-eye image light and the left-eye image light transmitted through the first polarizing region 31 and the second polarizing region 32 of the phase difference plate 8 are emitted, the stereoscopic glasses are applied as described above. By observing the display device 1, only the right eye image light can be observed with the right eye, and only the left eye image light can be observed with the left eye. Therefore, the observer 50 can recognize these right-eye image light and left-eye image light as a stereoscopic image.

  Next, as shown in FIG. 7B, when the observer 50 observes a stereoscopic image with the stereoscopic image display device 1, as described above, the image areas are switched in accordance with the switching of the frames, and the liquid crystal is displayed. A case where a left-eye image and a right-eye image are formed in the first image forming area 21 and the second image forming area 22 in the panel 6 will be described.

  As in the case described above, the left-eye image light transmitted through the first image forming region 21 and the right-eye image light transmitted through the second image forming region 22 in the liquid crystal panel 6 are indicated by arrows in FIG. The light passes through a polarizing plate 7 to be described later and becomes linearly polarized light having a polarization axis in a direction perpendicular to the horizontal direction.

Then, although it is incident on the phase difference plate 8, the left-eye image light is incident on the first polarization region 31 of the phase difference plate 8. Then, as indicated by an arrow in FIG. 7B, the incident left-eye image light is emitted as counterclockwise circularly polarized light. In the second polarizing region 32, the incident right-eye image light is emitted as clockwise circularly polarized light.
Next, the image light for the left eye and the image light for the right eye thus obtained are respectively incident on the polarizing glasses 10 worn by the observer 50.

At this time, when the polarizing glasses 10 are configured with the right-eye glasses unit 41 and the left-eye glasses unit 42 using the TN mode liquid crystal element, no voltage is applied to the TN liquid crystal cell, and the so-called OFF state is initially set. An alignment state is formed.
As a result, when left-eye image light, which is counterclockwise circularly polarized light, is incident on the right-eye glasses 41, the quarter-wave plate 43a included in the right-eye glasses 41 is indicated by an arrow in FIG. Is converted into linearly polarized light parallel to the horizontal direction, and further rotated 90 degrees in the TN liquid crystal cell 44a in the OFF state to be converted into linearly polarized light perpendicular to the horizontal direction, but enters the polarizing plate 45a but cannot be transmitted. And will not reach the right eye of the viewer 50.

  On the other hand, the left-eye image light that is counterclockwise circularly polarized light is incident on the left-eye glasses 42 and is transmitted through the quarter-wave plate 43b included in the left-eye glasses 42, and as shown by an arrow in FIG. Rotated to linearly polarized light perpendicular to direction. Then, in the TN liquid crystal cell 44b in the OFF state, it is further rotated 90 degrees to be converted into linearly polarized light parallel to the horizontal direction, passes through the polarizing plate 45b as it is, and reaches the left eye of the observer 50.

  Further, the right-eye image light that has been clockwise circularly polarized light passes through the quarter-wave plate 43a included in the right-eye glasses 41 and is perpendicular to the horizontal direction, as indicated by an arrow in FIG. 7B. Returned to linearly polarized light. Then, the TN liquid crystal cell 44a in the OFF state is rotated 90 degrees to be converted into linearly polarized light parallel to the horizontal direction, passes through the polarizing plate 45a as it is, and reaches the right eye of the observer 50.

  On the other hand, when the right-eye image light, which is clockwise circularly polarized light, is incident on the left-eye glasses unit 42, as shown by the arrow in FIG. Transmitted and rotated to linearly polarized light parallel to the horizontal direction. Then, the TN liquid crystal cell 44b in the OFF state is further rotated 90 degrees to be converted into linearly polarized light perpendicular to the horizontal direction, and enters the polarizing plate 45b, but cannot be transmitted through the polarizing plate 45b and is blocked, and the left eye of the observer 50 Will not reach.

  Thus, as described above, the frame is switched on the liquid crystal display 3 within the range in which the left-eye image light and the right-eye image light transmitted through the first polarizing region 31 and the second polarizing region 32 of the phase difference plate 8 are emitted. In synchronization with the switching of the image area, the stereoscopic image display device 1 is observed by wearing the polarized glasses 10 configured so that the phase difference state can be alternately switched on the left and right sides. Even when the image area in which the area for forming the left-eye image is replaced is changed, only the right-eye image light can be observed with the right eye, and only the left-eye image light can be observed with the left eye. Therefore, the observer 50 can always recognize these right-eye image light and left-eye image light as a stereoscopic image.

  Therefore, in the conventional stereoscopic image display device, the image area for forming the right-eye image and the left-eye image is fixed, so that the vertical resolution is halved and the resolution is lowered. The display device 1 can display at the full resolution with the full performance of the liquid crystal display 3 without reducing the resolution at all.

  In addition, in the conventional stereoscopic image display device, only one of the left and right eye images is always displayed, and there may be a time difference when recognizing a stereoscopic image. In the display device, images of the left and right pictures are always displayed, so that the viewer's feeling of fatigue can be reduced. In addition, there is also an effect that the sense of incongruity of stereoscopic vision caused by the shift of the left and right images that occurs in the case of a stereoscopic image that moves vigorously is not caused.

  Furthermore, the stereoscopic image display apparatus according to the present embodiment can be used even when the response speed of the liquid crystal element used in the necessary liquid crystal display and polarized glasses is slow. On the other hand, when the response speed of the liquid crystal element is fast, it is possible to obtain a stereoscopic image display with much higher brightness than before.

  In the stereoscopic image display apparatus 1 according to the present embodiment, a case will be described in which the polarizing glasses 10 configure the right eyeglass portion 41 'and the left eyeglass portion 42' using a ferroelectric liquid crystal element.

  In the ferroelectric liquid crystal element, the liquid crystal alignment state that is emitted with the same characteristics as the incident linearly polarized light out of the two selectable stable states described above is used in the same manner as the ON state of the TN mode liquid crystal element. be able to. An alignment state in which incident linearly polarized light can be emitted by rotating it 90 degrees counterclockwise or 90 degrees clockwise can be utilized in the same manner as the above-described TN mode liquid crystal element OFF state.

  That is, in the ferroelectric liquid crystal element, switching by applying a voltage is possible. As a result, the polarizing glasses 10 are configured using the TN mode liquid crystal element by appropriately selecting two stable alignment states that can be selected as desired. It is possible to obtain a polarization effect similar to that obtained.

  Therefore, the first polarizing region 31 and the second polarizing region 31 of the phase difference plate 8 are also used when the polarizing glasses 10 are configured with the right-eye glasses portion 41 ′ and the left-eye glasses portion 42 ′ using a ferroelectric liquid crystal element. By observing the stereoscopic image display device 1 with the polarizing glasses 10 as described above within the range in which the right-eye image light and the left-eye image light transmitted through the polarization region 32 are emitted, the right-eye image light is observed in the right eye. Only the image light for the left eye can be observed with the left eye. Therefore, the observer 50 can recognize these right-eye image light and left-eye image light as a stereoscopic image.

Next, the operation of the stereoscopic image display apparatus 1 according to the present embodiment will be described.
As described above, when displaying a stereoscopic image, the right-eye image and the left-eye image are simultaneously displayed on one frame image, and the left and right eyes of the observer are displayed using the phase difference plate that is the optical means described above. In order to display all image information, first, all horizontal scanning lines arranged continuously in the vertical direction of the frame display screen are respectively displayed from a plurality of horizontal lines. It is effective to divide into a first image forming area and a second image forming area.

  The first image formation area displays either the right-eye image or the left-eye image, and the second image formation area displays the other image at the same time. The left-eye image and the right-eye image correspond to the frame switching. All of the methods are used in which the image forming areas for displaying the images for use are exchanged at a predetermined cycle, and simultaneously the exchange of the image forming areas, the polarization performance of the right eye glasses 41 and the left eye glasses 42 of the polarizing glasses 10 is exchanged. This is useful for displaying and viewing video information.

  However, when the above-described liquid crystal display 3 is used in the stereoscopic image display device 1, as shown in FIG. 8, the frame image information is updated sequentially from the upper horizontal line to the lower horizontal line on the screen. Since the screen is overwritten and updated, the observer always sees the previous image and the next new image at the same time. As a result, there is a problem that there is much crosstalk and it is difficult to recognize a stereoscopic image. FIG. 8 is a diagram for explaining a general display method of a liquid crystal display.

  In order to solve such a problem, the stereoscopic image display apparatus 1 according to the present embodiment introduces a blinking operation of the backlight 2 to reduce crosstalk related to information update of the frame image.

  FIG. 9 is a diagram for explaining the operation of the stereoscopic image display apparatus 1 according to the present embodiment.

  As described above, the stereoscopic image display device 1 according to the present embodiment includes the backlight 2, the liquid crystal display 3, and the retardation plate 8 that is an optical means in this order. A display control unit 61 is provided, and these are also housed in a housing (not shown). Then, as described above, the stereoscopic image display device 1 includes the polarizing glasses 10 used by an observer who wants to observe a stereoscopic image.

  The display control unit 61 instructs the image output unit 60 to simultaneously output the right-eye image and the left-eye image on one frame image. In response to this instruction, the image output unit 60 is, for example, a first provided corresponding to a plurality of horizontal lines arranged continuously in the vertical direction of the liquid crystal panel 6 constituting the liquid crystal display 3 described in FIG. A right-eye image and a left-eye image are output and displayed in the image forming area 21 and the second image forming area 22, respectively.

  Then, every time the frame is switched, the image forming areas where the right-eye image and the left-eye image are displayed are alternately switched to display frame images in which the right-eye image and the left-eye image are alternately arranged. ing. However, in order to prevent the above-described crosstalk, the display control unit 61 instructs the image output unit 60 to display the right-eye image and the left-eye image on one frame image at the same time, and then displays the image in the next frame. It is possible to instruct to overwrite without changing the area, and to display the overwritten image on the liquid crystal display 3 for at least the next one frame period.

  At that time, the display control unit 61 controls the blinking of the backlight 2 at the same time, and controls the switching of the polarization state of the right-eye glasses unit 41 and the left-eye glasses unit 42 of the polarized glasses 10. That is, the backlight 2 is turned on during the period for displaying one frame image, and the backlight 2 is turned off in the frames before and after the image forming area in which the right-eye image and the left-eye image are displayed. Or, it is controlled so as to lower the luminance appropriately. By doing so, it is possible to prevent the observer 50 from detecting the above-described crosstalk based on the replacement of the afterimage and the image area of the right-eye image and the left-eye image.

  At the same time, the display control unit 61 instructs the infrared transmission device 9 provided in the housing of the liquid crystal display 3 in synchronization with the start timing of the frame for switching the image forming area in which the image for the right eye and the image for the left eye are displayed. Then, infrared rays are emitted as a synchronizing signal toward the infrared sensor 11 provided in the polarizing glasses 10. Then, for example, the TN liquid crystal cells 44a and 44b constituting the right eyeglass portion 41 and the left eyeglass portion 42 of the polarizing glasses 10 are driven by the infrared sensor 11 sensing the emitted infrared rays. That is, the TN liquid crystal cells 44a and 44b are driven and controlled to be in the ON state or the OFF state, thereby controlling the switching of the polarization state of the right eyeglass part 41 and the left eyeglass part 42 of the polarizing glasses 10.

  At this time, in the liquid crystal display 3, after the right-eye image and the left-eye image are simultaneously displayed on one frame image, the next frame can be overwritten as it is without changing the image area. However, the switching of the polarization state of the right eyeglass unit 41 and the left eyeglass unit 42 of the polarized glasses 10 is also controlled to be compatible.

That is, the polarization states of the right eye glasses 41 and the left eye glasses 42 of the polarizing glasses 10 are switched in synchronization with the start timing of the frame for switching the image forming areas where the right eye image and the left eye image are displayed. Then, in the subsequent frames in which the image area is not replaced by overwriting as it is, the display control unit 61 controls the polarization state not to be switched and to maintain the polarization state as it is.

  In this way, even if the areas for forming the right-eye and left-eye images are switched at a predetermined period corresponding to the frame switching, the observer 50 surely observes only the right-eye image light with the right eye. Therefore, only the left eye image light can be observed with the left eye. Therefore, the observer 50 can always recognize the right-eye image light and the left-eye image light as a stereoscopic image without sensing the above-described crosstalk based on the replacement of the image areas.

  As described above, when the right-eye image and the left-eye image are simultaneously displayed on one frame image and the image area is not replaced in the next frame and overwriting is performed as it is, the number of image replacements is as follows. At a normal frame frequency of 60 Hz that is possible in the liquid crystal display 3, the smoothness of the displayed image is lost. Moreover, in the backlight 2, the backlight blinking performed for each frame is performed at a cycle of 30 Hz, which is perceived by the observer, and there is a concern that the observer may feel flicker due to the perception.

  Therefore, it is preferable to improve the frame frequency in the liquid crystal display 3, for example, the frame frequency is 120 Hz or more. By doing so, after the image for the right eye and the image for the left eye are simultaneously displayed on one frame image, the image area is not replaced in the next frame, and the frame frequency corresponds to 60 Hz even when overwriting as it is. A stereoscopic image can be formed, the number of times that the image can be switched is increased, and there is no concern that flicker is felt by an observer. Further, flicker resulting from the blinking of the backlight 2 is not perceived by the observer. Therefore, the display image provided by the stereoscopic image display device 1 of the present embodiment is also natural.

  In the stereoscopic image display device 1 of the present embodiment, the frame frequency in the liquid crystal display 3 controlled by the control device 12 can be set to 240 Hz. In that case, the image for the right eye and the image for the left eye are simultaneously displayed on one frame image, the image area is not replaced in the next frame, and the image area is replaced in the next frame. It can be controlled by the control device 12 in such a pattern that it is performed and overwritten as it is in the subsequent frames. That is, it is possible to control the image formation by the control device 12 according to a pattern in which the display area of the right eye image and the left eye image on the liquid crystal display 3 and the overwriting as it is are repeated in that order for each frame. is there.

  When an image is formed on the liquid crystal display 3 in such a cycle, a three-dimensional image corresponding to a frame frequency of 120 Hz can be formed, the number of times the image can be switched is increased, and flicker is felt by an observer. There is no concern about it. Further, the backlight 2 is also blinked at a cycle of 120 Hz. The switching of the polarization states of the right-eye glasses unit 41 and the left-eye glasses unit 42 of the polarizing glasses 10 is performed at a cycle of 60 Hz because the polarization state is not switched in the frame for overwriting. Therefore, there is no concern that flicker or the like is perceived by the observer 50 by switching the polarization state of the right eyeglass portion 41 and the left eyeglass portion 42 of the polarized glasses 10.

  When the frame frequency of the liquid crystal display 3 is 240 Hz, the right eye image and the left eye image are simultaneously displayed on one frame image by frame switching, and then the image area is not replaced in the subsequent three frames. It is also possible to control the control device 12 so as to perform overwriting as it is, display the overwritten image on the liquid crystal display 3 for the next three frame periods, and form a stereoscopic image corresponding to the frame frequency of 60 Hz.

  In that case, the backlight 2 is turned off only for 1/240 seconds that is the first one frame period, and then the overwritten image display is performed. Then, the backlight 2 is turned on for 3/240 seconds that is the three frame period. it can. In that case, the number of replacements of the image area is reduced as compared with the pattern in which the display area replacement of the right-eye image and the left-eye image in the liquid crystal display 3 and the overwriting as it is are repeated for each frame. Thus, it is possible to reduce the period during which the backlight is off. As a result, the brightness of the stereoscopic display image in the stereoscopic image display apparatus 1 can be further improved.

At that time, the backlight 2 is also blinked in a cycle of 60 Hz correspondingly. Therefore, there is no concern that the flicker resulting from the flashing of the backlight 2 is perceived by the observer.
As described above, by improving the frame frequency of the liquid crystal display 3 such as 120 Hz or 240 Hz, it is possible to enjoy natural and high-quality stereoscopic display image display.

  The present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention.

DESCRIPTION OF SYMBOLS 1 Stereoscopic image display apparatus 2 Backlight 3 Liquid crystal display 5, 7, 45a, 45b, 45a ', 45b' Polarizing plate 6 Liquid crystal panel 8 Phase difference plate 9 Infrared transmitter 10 Polarizing glasses 11 Infrared sensor 21 First image formation area 22 Second image forming area 23 Horizontal line 24 Light-shielding part 25 Outer frame 26 Case 27 Adhesive 31 First polarizing area 32 Second polarizing area 41, 41 ′ Right eye glasses part 42, 42 ′ Left eye glasses parts 43a, 43b, 43a ′, 43b ′ ¼ wavelength plate 44a, 44b TN liquid crystal cell 50 observer 60 image output unit 61 display control unit

Claims (10)

A liquid crystal display having a liquid crystal panel configured by arranging a plurality of horizontal lines in which pixels are arranged in the horizontal direction in the vertical direction, and a pair of polarizing plates that sandwich the liquid crystal panel;
A backlight disposed on the back side of the liquid crystal display;
Optical means provided on the front side of the liquid crystal display;
Polarized glasses worn by the observer,
A stereoscopic image display device comprising:
The liquid crystal display includes a first image forming region and a second image forming region which are configured by bundling the plurality of horizontal lines arranged continuously in the vertical direction of the liquid crystal panel and are alternately arranged. The first image forming area is configured to simultaneously display one of the right eye image and the left eye image, and the second image forming area is configured to simultaneously display the other image.
The first image forming area and the second image forming area are (1) switching the right-eye image and the left-eye image every frame switching, or (2) other than (1), Is configured to either swap the image for the right eye and the image for the left eye or overwrite the image displayed in the previous frame when switching
The backlight is configured such that a lighting state is controlled in accordance with a timing at which the right-eye image and the left-eye image are switched.
The optical means has a position and a size corresponding to the first image forming area and the second image forming area, and a first polarizing area and a second polarizing area are arranged, and the first polarizing area Either one of the second polarizing regions constitutes a half-wave plate, or both constitute a quarter-wave plate and their optical axes are orthogonal to each other,
The polarized glasses have a right-eye glasses unit and a left-eye glasses unit, and are synchronized between the right-eye image unit and the left-eye image unit in synchronization with the timing of switching the right-eye image and the left-eye image unit. A three-dimensional image display device, characterized in that the phase difference state is alternately switched.   The stereoscopic image display apparatus according to claim 1, wherein a light shielding portion is provided at least at a part of a boundary between the first polarizing region and the second polarizing region of the optical unit.   Each of the first image forming area and the second image forming area is an image forming area composed of 2 to 60 horizontal lines arranged continuously in the vertical direction of the liquid crystal panel. The stereoscopic image display apparatus according to claim 1 or 2.   Each of the first image forming area and the second image forming area is an image forming area composed of 3 to 30 horizontal lines arranged continuously in the vertical direction of the liquid crystal panel. The stereoscopic image display apparatus according to claim 1 or 2. The polarized glasses are provided with an infrared sensor, and the liquid crystal display is provided with an infrared transmitter.
When the first image forming area and the second image forming area are synchronized with the timing at which the right-eye image and the left-eye image are switched, infrared rays are transmitted from the infrared transmission device, and the infrared sensor senses the infrared rays. 5. The stereoscopic image display device according to claim 1, wherein phase difference states are alternately switched between the right-eye glasses unit and the left-eye glasses unit. 6.   The right eyeglass part and the left eyeglass part are configured by using one of a TN type liquid crystal element and an STN type liquid crystal element. The stereoscopic image display device according to item.   6. The right-eye glasses part and the left-eye glasses part are configured using one of a ferroelectric liquid crystal element and an antiferroelectric liquid crystal element. The three-dimensional image display apparatus of any one of Claims.   The right eyeglass portion and the left eyeglass portion are any one liquid crystal selected from the group consisting of a VA liquid crystal element, an OCB liquid crystal element, a homogeneous ECB liquid crystal element, and a HAN ECB liquid crystal element. The stereoscopic image display apparatus according to claim 1, wherein the stereoscopic image display apparatus is configured using an element.   The stereoscopic image display device according to any one of claims 1 to 8, wherein the frame switching in the liquid crystal display is performed at a cycle of 120 Hz or more.   The stereoscopic image display device according to claim 9, wherein the frame switching in the liquid crystal display is performed at a cycle of 240 Hz or more.

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