JP2011154197A - 3d display - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To make it possible to switch between 2D display and 3D display in various forms without complicating its configuration. <P>SOLUTION: The display uses a lens array element which can be controlled to turn on/off the lens effect by changing the refractive index distribution in the liquid crystal layer depending on the voltage applied by the first electrode and the second electrode 21Y facing each other. It is built to electrically separate one of the first electrode and the second electrode 21Y into a number of predetermined areas so that the lens effect is turned on/off respectively for the predetermined areas in the lens array element, and capable of applying the voltage to the liquid crystal layer for every predetermined area. For example, the first electrode is made flat as a whole, and composing this flat electrode with the divided electrodes 11-1, 11-2 corresponding to the predetermined areas, and the predetermined drive voltages are applied respectively to the divided electrodes 11-1, 11-2. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a stereoscopic display device that can electrically switch between two-dimensional display and three-dimensional display using a variable lens array element.

  2. Description of the Related Art Conventionally, binocular or multi-view stereoscopic display devices that realize stereoscopic viewing by showing parallax images with parallax to both eyes of an observer are known. As a method for realizing these stereoscopic display devices, for example, a two-dimensional display device such as a liquid crystal display, and a three-dimensional display optical device that deflects display image light from the two-dimensional display device in a plurality of viewing angle directions ( A combination with a parallax separation means is known. As an optical device for three-dimensional display, for example, as shown in FIG. 26, a cylindrical lens array 302 in which a plurality of cylindrical lenses (cylindrical lenses) 303 are arranged in parallel is used. The cylindrical lens array 302 is disposed so as to face the display surface of the display panel 301 including a two-dimensional display device. Each cylindrical lens 303 is disposed so as to extend in the vertical direction with respect to the display surface of the display panel 301 and to have a refractive power in the left-right direction. A plurality of display pixels are regularly arranged in a two-dimensional manner on the display surface of the display panel 301. By arranging two or more pixels on the back of one cylindrical lens 303 and emitting light rays from each pixel in different horizontal directions depending on the refractive power of the lens, binocular parallax can be satisfied, and stereoscopic vision with the naked eye is possible Become.

  FIG. 26 shows an example of binocular stereoscopic display, and two adjacent pixel columns 301R and 301L on the display surface of the display panel 301 are assigned to each cylindrical lens 303. A right parallax image is displayed in one pixel column 301R, and a left parallax image is displayed in the other pixel column 301L. The displayed parallax images are distributed to the left and right optical paths 402 and 403 by the cylindrical lenses 303. Thus, when the viewer 400 views the stereoscopic display device from a predetermined position and a predetermined direction, the left and right parallax images appropriately reach the left and right eyes 401R and 401L of the viewer 400, and a stereoscopic image is perceived. .

  Similarly, in the case of the multi-view type, a plurality of parallax images captured at positions and directions corresponding to three or more viewpoints are equally divided and displayed within the lateral lens pitch of the cylindrical lens 303. As a result, three or more parallax images are emitted and imaged by the cylindrical lens array 302 in different continuous angular ranges. In this case, a plurality of different parallax images are perceived according to changes in the position and direction of the line of sight of the viewer 400. The more the change in the parallax image corresponding to the viewpoint change, the more realistic stereoscopic effect can be obtained.

  By the way, as the cylindrical lens array 302, for example, a resin-molded lens array having a fixed shape and lens effect can be used. In this case, since the lens effect is fixed, a display device dedicated to three-dimensional display is obtained. . On the other hand, a switchable lens array element using a liquid crystal lens can be used as the cylindrical lens array 302. In the case of a switchable lens array element using a liquid crystal lens, the presence / absence of a lens effect can be electrically switched, so that two display modes, a two-dimensional display mode and a three-dimensional display mode, are combined with a two-dimensional display device. Can be switched. That is, in the two-dimensional display mode, the lens array has no lens effect (no refractive power), and display image light from the two-dimensional display device is allowed to pass through as it is. In the three-dimensional display mode, the lens array is in a state in which a lens effect is generated, and stereoscopic vision is realized by deflecting display image light from the two-dimensional display device in a plurality of viewing angle directions.

  Referring to FIGS. 27 (A), (B), FIG. 28, FIGS. 29 (A), (B), and FIGS. 30 (A), (B), a switchable (variable) lens array using liquid crystal lenses. A configuration example of the element will be described. In these drawings, the structure of the electrode portion is mainly shown, and components such as the substrate and the alignment film are omitted. The variable lens array element includes a transparent first substrate and a second substrate made of, for example, a glass material, and a liquid crystal layer 130 sandwiched between the first substrate and the second substrate (FIG. 27 ( A) and (B)). The first substrate and the second substrate are arranged to face each other with a gap d.

  On the first substrate, a first electrode 111 made of a transparent conductive film such as an ITO film (Indium Tin Oxide) is uniformly formed on almost the entire surface (see FIGS. 28 and 30A). . A first alignment film is also formed on the first substrate so as to be in contact with the liquid crystal layer 130 with the first electrode 111 interposed therebetween. A second electrode 121Y made of a transparent conductive film such as an ITO film is partially formed over the second substrate (see FIGS. 28 and 30A). A second alignment film is also formed on the second substrate so as to be in contact with the liquid crystal layer 30 via the second electrode 121Y.

  FIGS. 27A and 27B show the basic principle of lens effect generation in this lens array element. In FIGS. 27A and 27B, the structure of the variable lens array element is simplified to explain the basic principle. The liquid crystal layer 130 includes liquid crystal molecules 131 so that the lens effect is controlled by changing the alignment direction of the liquid crystal molecules 131 according to the voltage applied to the first electrode 111 and the second electrode 121Y. It has become. The liquid crystal molecules 131 have refractive index anisotropy, and have, for example, a refractive index ellipsoidal structure in which the refractive index is different with respect to the passing light beam in the longitudinal direction and the short direction. The liquid crystal layer 130 is electrically switched between a state without a lens effect and a state where a lens effect occurs according to the state of a voltage applied to the first electrode 111 and the second electrode 121Y. ing.

  In this lens array element, as shown in FIG. 27A, in a normal state where the applied voltage is 0 V, the liquid crystal molecules 131 are aligned in a predetermined direction defined by the first alignment film and the second alignment film. It is arranged uniformly. For this reason, the wavefront 201 of the passing light is a plane wave, and there is no lens effect. On the other hand, in this lens array element, since the plurality of second electrodes 121Y are spaced apart at a predetermined interval, when a predetermined drive voltage is applied between the first electrode 111 and the second electrode 121Y, The electric field distribution in the liquid crystal layer 130 is biased. That is, in the portion corresponding to the region where the second electrode 121Y is formed, the electric field strength increases according to the driving voltage, and the electric field strength decreases toward the center of the opening between the plurality of second electrodes 121Y. Such an electric field is generated. For this reason, as shown in FIG. 27B, the arrangement of the liquid crystal molecules 131 changes in accordance with the electric field intensity distribution. As a result, the wavefront 202 of the passing light changes, and a lens effect is generated.

  FIG. 28 and FIG. 30 (A) show a planar configuration example of the electrode portion. FIG. 30B optically equivalently shows the lens shape formed in the case of the electrode structure shown in FIG. The second electrode 121Y has an electrode width of the width Lx and extends in the vertical direction (vertical direction). As shown in FIG. 30A, a plurality of second electrodes 121Y are arranged in parallel at a periodic interval corresponding to the lens pitch p when the lens effect is generated. When the lens effect is generated, a predetermined potential difference is provided between the upper and lower electrodes sandwiching the liquid crystal layer 130 so as to change the arrangement of the liquid crystal molecules 131. For example, as shown in FIG. 29B, a predetermined common voltage (for example, 0 V) is applied to the plurality of second electrodes 121Y, and a predetermined driving voltage having, for example, a rectangular waveform is applied to the first electrode 111. To do.

  Since the first electrode 111 is formed on the entire surface and the second electrode 121Y is partially formed with a gap in the lateral direction, there is a predetermined gap between the first electrode 111 and the second electrode 121Y. When the potential difference is generated, the electric field distribution in the liquid crystal layer 130 is biased according to the principle shown in FIG. 27B described above, and therefore the electric field distribution so that the lens effect is generated in the lateral direction (X-axis direction). Changes. That is, equivalently, as shown in FIG. 30B, a plurality of cylindrical lenses 31Y extending in the Y-axis direction and having refractive power in the X-axis direction are arranged in parallel in the X-axis direction. It becomes a lens state.

  In addition, a parallax barrier type is known as one capable of stereoscopic viewing with the naked eye. In the parallax barrier method, a structure called a parallax barrier is disposed as a parallax separation unit so as to face a two-dimensional display panel, and left and right parallax images displayed on the two-dimensional display panel are separated in a horizontal direction by the parallax barrier. Thus, stereoscopic viewing is performed. By making the parallax barrier a variable barrier using, for example, a liquid crystal display, switching display in two display modes of a two-dimensional display mode and a three-dimensional display mode is possible. However, in the case of the parallax barrier method, in the three-dimensional display mode, the display image light from the two-dimensional display panel is partially shielded by the parallax barrier, so that the observation image is compared with the method using the cylindrical lens described above. Becomes darker.

  Patent Document 1 discloses a liquid crystal lens in which a portion of the second electrode 121Y in the electrode structure shown in FIG. In this liquid crystal lens, the control of the electric field distribution formed in the liquid crystal layer can be more easily optimized by changing the arrangement interval of the transparent electrodes formed on one side of the liquid crystal layer between the first layer and the second layer. Yes.

JP 2008-9370 A

  As described above, by using the variable lens array element, it is possible to perform switching display in two display modes of the two-dimensional display mode and the three-dimensional display mode. However, conventionally, this display switching is limited to switching between two-dimensional (2D) display on the full screen and three-dimensional (3D) display on the full screen, as shown in FIG. ing. On the other hand, it is convenient if only a part of the screen can be displayed in 3D and the other part can be displayed in 2D. For example, since the resolution of the 3D display is lower than that of the 2D display, it is conceivable to use a 2D display for a video part that requires a high resolution, and a video material that includes a part that is not necessarily a 3D display. In this case, it is conceivable to make a two-dimensional display partly. For example, when a movie with subtitles is displayed three-dimensionally, the subtitle portion may be displayed in two dimensions. It would be convenient if the display in such various forms could be realized with a simple configuration.

  The present invention has been made in view of such problems, and an object of the present invention is to provide a stereoscopic display device that can switch between two-dimensional display and three-dimensional display in various forms without complicating the configuration. It is to provide.

  A stereoscopic display device according to a first aspect of the present invention includes a display panel that performs two-dimensional image display, a first electrode, and a second electrode that is disposed to face the first electrode, A liquid crystal layer disposed between the first electrode and the second electrode, and changing a refractive index distribution in the liquid crystal layer in accordance with a voltage applied by the first electrode and the second electrode; Accordingly, a lens array element configured to be able to variably control the lens effect on the display image light from the display panel between an on state and an off state is provided. In the lens array element, either one of the first electrode and the second electrode has a plurality of predetermined partial areas so that the lens effect can be turned on / off for each of the plurality of predetermined partial areas. And a structure capable of applying a voltage to the liquid crystal layer for each predetermined partial region.

  A stereoscopic display device according to a second aspect of the present invention includes a display panel that performs image display, a first electrode, a second electrode that is disposed to face the first electrode, and a first electrode. A liquid crystal layer disposed between the first electrode and the second electrode, and controls a lens effect on display image light from the display panel according to a voltage applied by the first electrode and the second electrode And a lens array element configured to be able to do this. Further, either one of the first electrode and the second electrode is electrically separated into a plurality of predetermined partial regions, and a structure capable of applying a voltage to the liquid crystal layer for each predetermined partial region It is what has been.

  A stereoscopic display device according to a third aspect of the present invention includes a display panel that performs image display, a first electrode, a second electrode that is disposed to face the first electrode, and a first electrode. And a liquid crystal layer disposed between the first electrode and the second electrode, and the direction of the refractive power with respect to the display image light from the display panel according to the voltage applied by the first electrode and the second electrode And a lens array element configured to be able to control the lens. Further, either one of the first electrode and the second electrode is electrically separated into a plurality of predetermined partial regions, and a structure capable of applying a voltage to the liquid crystal layer for each predetermined partial region It is what has been.

  In the stereoscopic display device according to the first, second, or third aspect of the present invention, any one of the first electrode and the second electrode that are arranged to face each other in the lens array element has a plurality of predetermined portions. By being electrically separated into regions, the state of voltage application to the liquid crystal layer can be controlled for each predetermined partial region. Thereby, in the lens array element, for example, the lens effect is set to an on state for a part of a plurality of predetermined partial regions, and the lens effect is set to an off state for other partial regions. Control can be performed, and three-dimensional display can be performed only in some partial areas, and two-dimensional display can be performed in other partial areas. Further, for example, it is possible to perform control such that the lens effect is switched between an off state and an on state for all of a plurality of predetermined partial regions, and switching between 2D display and 3D display on the entire screen can be performed. .

  According to the stereoscopic display device according to the first, second, or third aspect of the present invention, in the lens array element, any one of the first electrode and the second electrode that are arranged to face each other is provided with a plurality of Since the structure is such that a predetermined partial region is electrically separated and a voltage can be applied to the liquid crystal layer for each predetermined partial region, two-dimensional display and three-dimensional display can be performed in various forms without complicating the configuration. You can switch between dimensional display.

It is sectional drawing which shows an example of the whole structure of the three-dimensional display apparatus which concerns on one embodiment of this invention. It is sectional drawing which shows the other example of the whole structure of a three-dimensional display apparatus. (A) is a perspective view which shows the 1st structural example of the electrode part in a lens array element, (B) is a perspective view which shows the 2nd structural example of an electrode part. It is explanatory drawing about the partial area | region set to the three-dimensional display apparatus. It is explanatory drawing about the switching of the display state in a stereoscopic display device. (A) is explanatory drawing which shows an example of the display state in a stereoscopic display device, (B) shows the 1st structural example and drive example of the electrode part for implement | achieving the display state shown to FIG. 6 (A). Explanatory drawing (C) is explanatory drawing which shows the 2nd structural example and drive example of the electrode part for implement | achieving the display state shown to FIG. 6 (A). It is a wave form diagram which shows an example of the drive voltage applied to the electrode part in a lens array element. It is explanatory drawing which shows the modification of the setting of a partial area | region. It is explanatory drawing which shows the other modification of the setting of a partial area | region. It is explanatory drawing which shows the further another modification of the setting of a partial area | region. (A) is explanatory drawing which shows the modification of the display state in a stereoscopic display device, (B) is the 1st structural example and drive example of the electrode part for implement | achieving the display state shown to FIG. 11 (A). FIG. 10C is an explanatory diagram illustrating a second configuration example and a driving example of an electrode portion for realizing the display state illustrated in FIG. (A) is explanatory drawing which shows the modification of the display state in a stereoscopic display device, (B) is the 1st structural example and drive example of the electrode part for implement | achieving the display state shown to FIG. 12 (A). FIG. 10C is an explanatory diagram illustrating a second configuration example and driving example of an electrode portion for realizing the display state illustrated in FIG. (A) is explanatory drawing which shows the modification of the display state in a stereoscopic display device, (B) is explanatory drawing which shows the structural example and drive example of an electrode part for implement | achieving the display state shown to FIG. 13 (A). It is. (A) is explanatory drawing which shows the modification of the display state in a stereoscopic display device, (B) is the 1st structural example and drive example of the electrode part for implement | achieving the display state shown to FIG. 14 (A). FIG. 14C is an explanatory diagram illustrating a second configuration example and driving example of an electrode portion for realizing the display state illustrated in FIG. (A) is explanatory drawing which shows the modification of the display state in a three-dimensional display apparatus, (B) is the 1st structural example and drive example of the electrode part for implement | achieving the display state shown to FIG. 15 (A). FIG. 14C is an explanatory diagram illustrating a second configuration example and driving example of an electrode portion for realizing the display state illustrated in FIG. It is explanatory drawing which shows the specific example of the display form by a stereoscopic display device. It is explanatory drawing which shows the other specific example of the display form by a three-dimensional display apparatus. It is sectional drawing which shows the 1st structure of the three-dimensional display apparatus which concerns on the Example of this invention. It is sectional drawing which shows the 2nd structure of the three-dimensional display apparatus which concerns on an Example. It is a perspective view which shows the structure of the electrode part of the three-dimensional display apparatus which concerns on an Example. It is a top view which shows the structure of the display panel in the three-dimensional display apparatus which concerns on an Example. It is a top view which shows the structure of the electrode part in the three-dimensional display apparatus which concerns on an Example. It is explanatory drawing which shows typically the structure of the 1st measurement system used for evaluation of display quality. It is explanatory drawing which shows typically the structure of the 2nd measurement system used for evaluation of display quality. It is explanatory drawing which shows the evaluation result of the display quality of the three-dimensional display apparatus which concerns on an Example. It is explanatory drawing which shows the concept of the three-dimensional display using the conventional cylindrical lens. It is sectional drawing which shows the basic structural example of the conventional variable lens array element, (A) shows the state without a lens effect, (B) shows the state which generated the lens effect. It is a top view which shows the structural example of the electrode part in the conventional variable lens array element. (A) is explanatory drawing about the switching of the display state at the time of using the conventional variable type lens array element, (B) is the drive voltage applied to the electrode part in the conventional variable type lens array element. It is explanatory drawing which shows an example. (A) is a perspective view showing a configuration example of an electrode portion of a conventional variable lens array element, and (B) is a perspective view optically equivalently showing a lens shape formed by the variable lens array element. FIG.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

[Overall configuration of stereoscopic display device]
FIG. 1 shows an example of a stereoscopic display device according to an embodiment of the present invention. This stereoscopic display device includes a display panel 2 that performs two-dimensional image display, and a lens array element 1 that is disposed so as to face the display surface 2A side of the display panel 2.

  This stereoscopic display device selectively switches between three display modes: a two-dimensional (2D) display mode on a full screen, a three-dimensional (3D) display mode on a full screen, and a partial three-dimensional display mode. It is possible. In this stereoscopic display device, as shown in FIG. 4, two partial areas having the same area size are set on the left and right. Then, it is possible to selectively switch between 2D display and 3D display for each partial region. As a result, for example, display states as shown in FIGS. 5A to 5D can be arbitrarily selected. That is, a state in which each partial region is displayed in 2D (FIG. 5A), a state in which each partial region is displayed in 3D (FIG. 5B), a left partial region in 2D display, and The state can be switched between the state in which the right partial region is displayed in 3D (FIG. 5C) and the state in which the left partial region is displayed in 3D and the right partial region is displayed in 2D (FIG. 5D). It is said that.

  As will be described later, the lens array element 1 is a variable lens array based on a liquid crystal lens system, and can electrically control the on / off of the lens effect for each partial region. The lens array element 1 selectively changes the passage state of light rays from the display panel 2 for each partial region by controlling the lens effect for each partial region in accordance with the display mode. The display panel 2 performs video display based on two-dimensional image data for a partial region for two-dimensional display, and performs video display based on three-dimensional image data for a partial region for three-dimensional display. The three-dimensional image data is data including a plurality of parallax images corresponding to a plurality of viewing angle directions in a three-dimensional display, for example. For example, when performing binocular three-dimensional display, the data is parallax image data for right-eye display and left-eye display.

  In the present embodiment, the horizontal direction (horizontal direction) is defined as the X direction and the vertical direction (vertical direction) is defined as the Y direction in a plane parallel to each substrate surface of the lens array element 1 or each substrate surface of the display panel 2. explain. Basically, the horizontal direction of the display surface 2A of the display panel 2 is the X direction, and the vertical direction is the Y direction.

[Configuration of Display Panel 2]
The display panel 2 includes, for example, a plurality of pixels including R (red) pixels, G (green) pixels, and B (blue) pixels, and the plurality of pixels are arranged in a matrix. The number of pixels of the display panel 2 is N (an integer greater than or equal to 2) with respect to the pitch p of the cylindrical lens formed by the lens array element 1. In the three-dimensional display mode, the number of rays (number of lines of sight) in the three-dimensional display is presented for this N. The display panel 2 can be composed of a liquid crystal display, for example. When the display panel 2 is constituted by a transmissive liquid crystal display, for example, two-dimensional image display is performed by modulating light from the backlight for each pixel in accordance with image data. The display panel 2 may be a self-luminous display such as an organic EL (Electro-Luminescence) display or a field emission display (FED).

[Entire configuration of lens array element 1]
As shown in FIG. 1, the lens array element 1 includes a first substrate 10 and a second substrate 20 that are arranged to face each other with a gap d, and between the first substrate 10 and the second substrate 20. And a liquid crystal layer 3 disposed on the surface. The first substrate 10 and the second substrate 20 are transparent substrates made of, for example, a glass material or a resin material. On the side of the first substrate 10 facing the second substrate 20, a first electrode 11 made of a transparent conductive film such as an ITO film is formed on almost the entire surface. A first alignment film 13 is also formed on the first substrate 10 so as to be in contact with the liquid crystal layer 3 through the first electrode 11. On the second substrate 20 on the side facing the first substrate 10, a second electrode 21Y made of a transparent conductive film such as an ITO film is partially formed. A second alignment film 23 is also formed on the second substrate 20 so as to be in contact with the liquid crystal layer 3 via the second electrode 21Y.

  The liquid crystal layer 3 includes the liquid crystal molecules 5, and the lens effect is controlled by changing the alignment direction of the liquid crystal molecules 5 according to the voltage applied to the first electrode 11 and the second electrode 21Y. It has become. The liquid crystal molecules 5 have refractive index anisotropy, and have, for example, a refractive index ellipsoidal structure in which the refractive index is different with respect to the passing light in the longitudinal direction and the short direction. The liquid crystal layer 3 is electrically switched between a state without a lens effect and a state where a lens effect occurs according to the state of a voltage applied to the first electrode 11 and the second electrode 21Y. ing. In this lens array element 1, the basic principle of the lens effect generation is the same as that of the liquid crystal lens shown in FIGS.

  As shown in FIG. 2, the dielectric layer 25 may be disposed between the second electrode 21 </ b> Y and the second alignment film 23. By disposing the dielectric layer 25, when the lens effect is generated in the lens array element 1, it is possible to obtain an ideal lens effect by making the refractive index distribution in the liquid crystal layer 3 more ideal.

[Electrode structure of lens array element 1]
The second electrode 21Y is composed of a plurality of line electrodes that are spaced apart from each other, and has an electrode width of the width Lx and extends in the vertical direction as shown in FIG. A plurality of the second electrodes 21Y are arranged in parallel at a periodic interval corresponding to the lens pitch p when the lens effect is generated. When the lens effect is generated, a predetermined potential difference is provided between the upper and lower electrodes sandwiching the liquid crystal layer 3 so that the arrangement of the liquid crystal molecules 5 can be changed. The first electrode 11 is a planar electrode as a whole. Since the second electrode 21Y is partially formed with a gap in the lateral direction, when a voltage is applied between the first electrode 11 and the second electrode 21Y, it is shown in FIG. The electric field distribution in the liquid crystal layer 3 is biased by the same principle as in the case. That is, an electric field is generated in the portion corresponding to the region where the second electrode 21Y is formed, and the electric field strength increases according to the driving voltage, and the electric field strength decreases as the distance from the second electrode 21Y increases in the lateral direction. To do. That is, the electric field distribution changes so that the lens effect (refractive power) is generated in the lateral direction (X direction). That is, equivalently, as in the case shown in FIG. 30B, a lens in which a plurality of cylindrical lenses 31Y extending in the Y direction and having refractive power in the X direction are arranged in parallel in the X direction. It becomes a state.

  FIG. 3A shows a first specific configuration example of the electrode portion of the lens array element 1. FIG. 3B shows a second specific configuration example. Note that in FIGS. 3A and 3B, the number of the second electrodes 21Y is simplified to be slightly smaller for convenience of explanation. In the lens array element 1, either one of the first electrode 11 and the second electrode 21Y includes a plurality of elements so that the lens effect can be turned on / off for each partial region shown in FIG. The liquid crystal layer 3 is configured to be electrically separated into partial areas and to apply a voltage to the liquid crystal layer 3 for each partial area.

  FIG. 3A shows a structure in which the first electrode 11 is divided into a first divided electrode 11-1 and a second divided electrode 11-2 corresponding to the left and right partial regions. A predetermined drive voltage can be applied. In this configuration, a predetermined common voltage is applied to the plurality of line electrodes constituting the second electrode 21Y as a whole.

  In FIG. 3B, a plurality of line electrodes constituting the second electrode 21Y are electrically connected to the first separation electrode 21Y-1 and the second separation electrode 21Y-2 in correspondence with the left and right partial regions. And a predetermined drive voltage can be applied to each separation electrode. In the case of this configuration, the first electrode 11 is a uniform flat electrode as a whole, and a predetermined common voltage is applied to the whole.

[Manufacture of lens array elements]
When the lens array element 1 is manufactured, first, a transparent conductive film such as an ITO film is formed in a predetermined pattern on each of the first substrate 10 and the second substrate 20 made of, for example, a glass material or a resin material. Thus, the first electrode 11 and the second electrode 21Y are formed. The first and second alignment films 13 and 23 are formed by a rubbing method in which a polymer compound such as polyimide is rubbed in one direction with a cloth, or an oblique deposition method such as SiO. Thereby, the major axis of the liquid crystal molecules 5 is aligned in one direction. On the first and second alignment films 13 and 23, in order to keep the distance d between the first substrate 10 and the second substrate 20 uniform, the spacer 4 made of a glass material or a resin material as a sealing material. Prints with dispersed. And the 1st board | substrate 10 and the 2nd board | substrate 20 are bonded together, and the sealing material containing a spacer is hardened. Thereafter, a known liquid crystal material such as TN or STN is injected between the first substrate 10 and the second substrate 20 from the sealing material opening to seal the sealing material opening. And after heating a liquid-crystal composition to an isotropic phase, it cools slowly, and the lens array element 1 is completed. In the present embodiment, the larger the refractive index anisotropy Δn of the liquid crystal molecules 5, the larger the lens effect is obtained. Therefore, it is preferable that the liquid crystal material has such a content composition. On the other hand, in the case of a liquid crystal composition having a large refractive index anisotropy Δn, on the contrary, the physical properties of the liquid crystal composition are impaired, and the injection between the substrates becomes difficult due to the increase in viscosity, or close to a crystal at a low temperature. In some cases, the internal electric field increases and the driving voltage of the liquid crystal element increases. For this reason, it is preferable to make the content composition considering both manufacturability and lens effect.

[Operation of stereoscopic display device]
In this image display device, in the lens array element 1, the lens effect is set to the off state for all of the plurality of partial regions, and the display image light from the display panel 2 is transmitted without being refracted, so that the entire screen is displayed. Perform two-dimensional display.

  Further, in the lens array element 1, the lens effect is set to an on state for all of the plurality of partial areas, and the display image light from the display panel 2 is refracted so as to enable stereoscopic viewing, so that it can be displayed on the entire screen. Perform 3D display.

  Further, in the lens array element 1, the lens effect is set to an on state for some partial areas of the plurality of partial areas, and the display image light from the display panel 2 is refracted so as to enable stereoscopic viewing. Thus, three-dimensional display is performed in a partial area. In addition, the lens effect is set to the off state for the other partial areas, and the display image light from the display panel 1 is transmitted without being refracted, thereby performing two-dimensional display in the other partial areas.

  As an example, a method of driving the lens array element 1 will be described in the case where the left partial area is displayed in 3D and the right partial area is displayed in 2D as shown in FIG. FIG. 6B shows the driving in the case where the first electrode 11 is divided into the first divided electrode 11-1 and the second divided electrode 11-2 as shown in FIG. An example is shown. In this case, a predetermined common voltage (for example, 0 V) is applied to the plurality of line electrodes constituting the second electrode 21Y. As for the first electrode 11, a predetermined drive voltage is applied to the first divided electrode 11-1 corresponding to the left partial region for 3D display. As the predetermined drive voltage, for example, a rectangular wave voltage as shown in FIG. 7 is applied. As a result, the lens effect is turned on for the left partial region. A predetermined common voltage (for example, 0 V) is applied to the second divided electrode 11-2 corresponding to the right partial region for 2D display so as to have the same potential as the second electrode 21Y. As a result, the lens effect is turned off for the right partial region.

  FIG. 6C shows a driving example in the case where the first separation electrode 21Y-1 and the second separation electrode 21Y-2 are electrically separated as shown in FIG. 3B. ing. In this case, a predetermined common voltage (for example, 0 V) is applied to the entire first electrode 11. For the second electrode 21Y, a predetermined drive voltage is applied to the first separation electrode 21Y-1 corresponding to the left partial region for 3D display. As the predetermined drive voltage, for example, a rectangular wave voltage as shown in FIG. 7 is applied. As a result, the lens effect is turned on for the left partial region. A predetermined common voltage (for example, 0 V) is applied to the second separation electrode 21Y-2 corresponding to the right partial region for 2D display so as to have the same potential as the first electrode 11. As a result, the lens effect is turned off for the right partial region.

<Modification>
In this stereoscopic display, the number and size of partial areas set are not limited to the example shown in FIG. 4, and various modifications can be considered. In that case, the electrode structure may be a structure according to the setting of the partial region. For example, the first electrode 11 may be a divided electrode corresponding to the partial region.

[Modification of partial area setting]
8A to 8C show an example in which a plurality of partial areas are set in the vertical direction of the screen. FIG. 8A shows an example in which there are two partial areas in the vertical direction, and the size of the lower partial area is set smaller than that of the upper partial area. FIG. 8B shows an example in which there are three partial areas in the vertical direction, and the second and third partial areas that are smaller in size than the first partial area on the upper side are set on the lower side. FIG. 8C shows an example in which four partial areas are set by equal division in the vertical direction. It is also possible to set the partial area in the vertical direction finer than the illustrated one. The size of the minimum partial area can be finely set up to a portion corresponding to the lens pitch.

  9A to 9C show an example in which a plurality of partial areas are set in the horizontal direction. FIG. 9A shows an example in which three partial areas are set by equal division in the horizontal direction. FIG. 9B shows an example in which there are three partial areas in the horizontal direction, and the second and third partial areas that are smaller in size than the first partial area on the left side are set on the left side. FIG. 9C shows an example in which there are three partial areas in the horizontal direction, and the second and third partial areas that are smaller in size than the central first partial area are set to the left and right. It is also possible to set the partial area in the horizontal direction more finely than what is shown. The size of the minimum partial area can be finely set up to a portion corresponding to the lens pitch.

  In addition, as shown in FIGS. 10A to 10D, it is also possible to set a plurality of partial areas both in the vertical direction and in the horizontal direction. In addition to this, for example, when the first electrode 11 is formed of a divided electrode corresponding to a partial region, the partial region can be set in various forms as long as the connection terminal can be taken from the outer peripheral portion. .

[Partial area setting and electrode structure modification]
11 (B) and 11 (C), as shown in FIG. 11 (A), when three partial areas are set in the horizontal direction by equal division and only the left and right partial areas are displayed in 3D, A specific example of the structure and its driving example are shown. In FIG. 11B, the first electrode 11 is divided into a first divided electrode 11-1, a second divided electrode 11-2, and a third divided electrode 11-3 corresponding to each partial region. An example of driving in the case of a structure is shown. In this case, a predetermined common voltage (for example, 0 V) is applied to the plurality of line electrodes constituting the second electrode 21Y. For the first electrode 11, a predetermined drive voltage is applied to the first divided electrode 11-1 and the second divided electrode 11-2 corresponding to the left and right partial regions for 3D display. As the predetermined drive voltage, for example, a rectangular wave voltage as shown in FIG. 7 is applied. As a result, the lens effect is turned on for the left and right partial regions. A predetermined common voltage (for example, 0 V) is applied to the third divided electrode 11-3 corresponding to the central partial region for 2D display so as to have the same potential as the second electrode 21Y. As a result, the lens effect is turned off for the central partial region.

  FIG. 11C shows a case where the second electrode 21Y is electrically separated into a first separation electrode 21Y-1, a second separation electrode 21Y-2, and a third separation electrode 21Y-3. An example of driving is shown. In this case, a predetermined common voltage (for example, 0 V) is applied to the entire first electrode 11. For the second electrode 21Y, a predetermined drive voltage is applied to the first separation electrode 21Y-1 and the second separation electrode 21Y-2 corresponding to the left and right partial regions to be 3D displayed. As the predetermined drive voltage, for example, a rectangular wave voltage as shown in FIG. 7 is applied. As a result, the lens effect is turned on for the left and right partial regions. A predetermined common voltage (for example, 0 V) is applied to the third separation electrode 21Y-3 corresponding to the central partial region for 2D display so as to have the same potential as the first electrode 11. As a result, the lens effect is turned off for the central partial region.

  12 (B) and 12 (C), as shown in FIG. 12 (A), in the case where two partial areas are set in the vertical direction and only the upper partial area is displayed in 3D, the electrodes A specific example of the structure and its driving example are shown. FIG. 12B shows an example of driving when the first electrode 11 is divided into a first divided electrode 11-1 and a second divided electrode 11-2 so as to correspond to each partial region. ing. FIG. 12C shows a case where the second electrode 21Y is divided into a first divided electrode 21Y-10 and a second divided electrode 21Y-20 corresponding to two partial regions. An example of driving is shown.

  FIG. 13B shows a specific example of an electrode structure in the case where three partial areas are set in an up-and-down direction as shown in FIG. 13A and only the central partial area is displayed in 3D. And a driving example thereof. In FIG. 13B, the first electrode 11 is divided into a first divided electrode 11-1, a second divided electrode 11-2, and a third divided electrode 11-3 corresponding to each partial region. An example of driving in the case of a structure is shown.

  14 (B) and 14 (C), as shown in FIG. 14 (A), one partial area having a large area size is set on the upper side, and two partial areas having a small area size are set on the lower side. A specific example of the electrode structure and a driving example thereof are shown in the case where only the lower left partial region is set to 3D display. In FIG. 14B, the first electrode 11 is divided into a first divided electrode 11-1, a second divided electrode 11-2, and a third divided electrode 11-3 corresponding to each partial region. An example of driving in the case of a structure is shown. In FIG. 14C, the second electrode 21Y is divided into the first divided electrode 21Y-10 and the second divided electrode 21Y-20 in the vertical direction, and the second divided electrode 21Y-20. The drive example is shown in the case where the structure is further electrically separated into the first separation electrode 21Y-21 and the second separation electrode 21Y-22.

  15 (B) and 15 (C), as shown in FIG. 15 (A), the whole is equally divided in the up and down direction and the left and right direction, and a total of four partial areas are set. A specific example of an electrode structure and a driving example thereof are shown for a case where only a region is displayed in 3D. FIG. 15B shows the first divided electrode 11-1, the second divided electrode 11-2, the third divided electrode 11-3, and the fourth divided electrode 11 corresponding to each partial region. The drive example at the time of setting it as the structure divided | segmented into the division | segmentation electrode 11-4 is shown. In FIG. 15C, the second electrode 21Y is divided into a first divided electrode 21Y-10 and a second divided electrode 21Y-20 in the vertical direction, and the first divided electrode 21Y-10. Is electrically separated into the first separation electrode 21Y-11 and the second separation electrode 21Y-12, and the second separation electrode 21Y-20 is further separated from the third separation electrode 21Y-13 and the second separation electrode 21Y-12. The drive example at the time of setting it as the structure electrically separated from the electrode 21Y-14 is shown.

[Specific examples of display formats]
As described above, according to the stereoscopic display device according to the present embodiment, the lens array element 1 is configured so as to enable the on / off control of the lens effect for each of a plurality of predetermined partial regions. Can be switched between two-dimensional display and three-dimensional display in various forms. Thereby, for example, it is possible to easily read subtitles or texts on a portion where a stereoscopic photograph or a stereoscopic video is displayed, and display it in the same screen in high-definition 2D display. In addition, since the setting of the partial area is set to a specific pattern, complicated driver circuits and wirings can be made almost unnecessary and can be implemented at low cost.

  FIGS. 16A, 16 </ b> B, and 17 illustrate examples of display forms when a three-dimensional display is partially performed in the stereoscopic display device described above. FIGS. 16A and 16B show examples of display forms when two partial areas having the same area size are set to the left and right. For example, as shown in FIG. 16A, a mode in which a 3D photograph is displayed in the left partial area and a calendar or a clock is displayed in 2D in the right partial area is conceivable. In addition, as shown in FIG. 16B, a mode in which a 3D game screen is displayed in the left partial area and character information related to the game is displayed in 2D in the right partial area is conceivable.

  FIG. 17 shows an example of a display form when there are two partial areas in the vertical direction, and the size of the lower partial area is set smaller than the upper partial area. When such a partial area is set, it is convenient to display a 3D movie with subtitles, for example. For example, it is conceivable to display a 3D movie image main body part in the upper wide partial area and display subtitles in 2D in the lower narrow partial area.

  Next, specific examples of the stereoscopic display device according to this embodiment will be described.

  18 and 19 illustrate the configuration of the stereoscopic display device according to the present embodiment. In FIG. 19, a dielectric layer 25 is disposed between the second electrode 21 </ b> Y and the second alignment film 23 with respect to the configuration of FIG. 18, and the other configurations are the same. In this embodiment, as the first substrate 10 and the second substrate 20 of the lens array element 1, an electrode substrate in which a transparent electrode made of ITO is provided on a glass substrate is used. Then, the electrode shapes of the first electrode 11 and the second electrode 21Y were patterned by a known photolithography method and wet etching or dry etching method. Each of the alignment films 13 and 23 was formed by spin-coating polyimide on the electrode and baking it. After firing the material, the surfaces of the alignment films 13 and 23 were rubbed, and further washed and heated and dried with IPA or the like. After cooling, the first substrate 10 and the second substrate 20 were bonded at a predetermined interval d so that the rubbing directions face each other. This distance d was maintained by dispersing the spacers over the entire surface. Thereafter, a liquid crystal material was injected from the opening of the sealing material by a vacuum injection method to seal the opening of the sealing material. The liquid crystal cell was heated to an isotropic phase and then gradually cooled. The liquid crystal material used in this example was MBBA (p-methoxybenzylidene-p'-butylaniline), which is a typical nematic liquid crystal. The value of the refractive index anisotropy Δn is 0.255 at 20 ° C.

  As the display panel 2, a TFT-LCD panel having a pixel size of 81 μm was used. The display panel 2 includes a plurality of pixels including R (red) pixels, G (green) pixels, and B (blue) pixels, and the plurality of pixels are arranged in a matrix. In addition, the number of pixels of the display panel 2 is an integral multiple of 2 or more N with respect to the pitch p of the cylindrical lens formed by the lens array element 1. The number of rays (the number of lines of sight) in the three-dimensional display is presented for this N.

As an electrode structure of the lens array element 1, as shown in FIG. 20, the first electrode 11 is divided into a first divided electrode 11-1 and a second divided electrode 11-2 in the vertical direction. I made it. The vertical length W1 of the first divided electrode 11-1 was three times as large as the vertical length W2 of the second divided electrode 11-2. That is,
W1: W2 = 3: 1
It is.

  Table 1 below shows the values of design parameters set as Examples 1 to 4 in [Table 1]. N indicates the number of pixels with respect to the lens pitch p of the display panel 2. The interval s is the distance between the first divided electrode 11-1 and the second divided electrode 11-2 as shown in FIG. In addition, the meanings of the electrode width Lx and the like are as shown in FIG. In addition, the structure of this invention is not limited to the value of the design parameter of the Example shown below.

  In Examples 1 to 4, a display panel 2 having a 3-inch WVGA (864 × 480 pixels) as shown in FIG. 21 was used. 22A and 22B show the electrode structure of the lens array element 1 corresponding to the pixel configuration of the display panel 2 shown in FIG. 22A shows the electrode structure on the first substrate 10 side, and FIG. 22B shows the electrode structure on the second substrate 20 side.

  As a comparative example, a structure in which the first electrode 11 is not divided (the structure shown in FIG. 29B) was prepared. The values of design parameters set as Comparative Examples 1 to 4 are shown in [Table 2].

  In Examples 1 to 4 and Comparative Examples 1 to 4, it was standard to use a rectangular wave of 30 Hz or more as an external power source used for the drive voltage to the first electrode 11. The amplitude voltage at that time was about 5 V to 10 V, and was adjusted according to the pitch of the cylindrical lens, the gap between the upper and lower electrode substrates, and the like. As the substrate distance d increases, the amplitude voltage needs to be set higher. There is a region where the visibility is hardly changed even if the drive amplitude voltage is increased little by little, and the voltage value immediately before saturation is set as the drive voltage. In addition, by applying 0 V, an approximate time (OFF response time) was observed when the 2D display mode was set.

[Evaluation of display quality of 3D display]
About each of the said Examples 1-4 and Comparative Examples 1-4, the display quality of the three-dimensional display apparatus was evaluated. 23 and 24 show the concept of the measurement system used for the evaluation of the display quality. FIG. 23 shows the measurement system used for the evaluation of Examples 1-2 and Comparative Examples 1-2, and FIG. 24 shows the measurement system used for the evaluation of Examples 3-4 and Comparative Examples 3-4.

  In FIG. 23, a configuration is adopted in which four pixels of the display panel 2 are arranged with respect to one lens width of the cylindrical lens 31Y formed by the lens array element 1. One pixel of the display panel 2 includes three sub-pixels of R (red), G (green), and B (blue). With respect to the stereoscopic display device having such a configuration, a photodiode 80 capable of observing the light intensity is disposed at a distance of 50 mm, and the measurement system is configured to move in parallel with the display panel 2. In FIG. 23, R, G. All of B are turned on to display white (for the right eye), and R, G. A photodiode 80 capable of observing the light intensity is arranged at a distance of 50 mm in each situation with respect to the one in which all of B is turned on to display white (for the left eye) and in the moving direction. The light intensity was measured accordingly.

  In FIG. 24, a configuration is adopted in which two pixels of the display panel 2 are arranged with respect to one lens width of the cylindrical lens 31Y formed by the lens array element 1. In FIG. 24, R, G. All of B are turned on to display white (for the right eye), and R, G. A photodiode 80 capable of observing the light intensity is arranged at a distance of 50 mm in each situation with respect to the one in which all of B is turned on to display white (for the left eye) and in the moving direction. The light intensity was measured accordingly.

  FIG. 25 shows the measurement result of the light intensity distribution in Example 1. In FIG. 25, the horizontal axis represents the light intensity detection position (mm) by the photodiode 80, and the vertical axis represents the light intensity (arbitrary unit (arbitrary unit)). In FIG. 25, the position where the light intensity reaches a peak corresponds to the line-of-sight position when performing stereoscopic display.

Here, a crosstalk value corresponding to a pupil distance of 65 mm is converted at a viewing distance of 500 mm. Ideally, the left eye only observes the light beam for the left eye and the right eye only the light beam for the right eye when the pupil distance is 65 mm, but the left eye observation as shown in FIG. At the position, not only the left-eye light beam but also the right-eye light beam overlap. That is, these are defined as crosstalk, and it is desirable that they be zero as much as possible. In quantifying crosstalk,
Intensity of either left or right / total intensity of both left and right x 100 (%)
It is defined as
Furthermore, the measurement area is nine places in the corresponding area (vertical 3 × horizontal 3), and the average value is shown.
[Table 3] shows the crosstalk amounts of Examples 1 to 4, and [Table 4] shows the crosstalk amounts of Comparative Examples 1 to 4.

  In Examples 1 to 4, the crosstalk amount was the same regardless of whether it was the full 3D display mode or the partial 3D display mode, and there was no influence due to electrode division. Furthermore, the amount of crosstalk is the same as in Comparative Examples 1 to 4 for each example, and there is no influence due to electrode division.

  On the other hand, 2D display quantification includes parameters such as luminance and chromaticity with respect to the viewing angle. In Examples 1 to 4, when the viewing angle dependency of luminance and chromaticity was measured when the lens effect of the liquid crystal lens portion was off, the deterioration was 80 to 90% as compared to the case without the liquid crystal lens portion. It was. In this embodiment, since measures such as an AR film for preventing reflection are not taken, this degree of deterioration is inevitable. In other words, if the same measures are taken, almost no deterioration during 2D display is observed. it is conceivable that. The evaluation result of the 2D display was exactly the same whether it was the full 2D display mode or the partial 2D display mode.

  DESCRIPTION OF SYMBOLS 1 ... Lens array element, 2 ... Display panel, 2A ... Display surface, 3 ... Liquid crystal layer, 5 ... Liquid crystal molecule, 10 ... 1st board | substrate, 11 ... 1st electrode, 11-1 ... 1st division | segmentation electrode, 11-2 ... second divided electrode, 11-3 ... third divided electrode, 11-4 ... fourth divided electrode, 13 ... first alignment film, 20 ... second substrate, 21Y ... second Electrode, 21Y-1 ... first separation electrode, 21Y-2 ... second separation electrode, 21Y-3 ... third separation electrode, 21Y-10 ... first division electrode, 21Y-20 ... second division Electrode, 21Y-11, 21Y-21 ... first separation electrode, 21Y-12, 21Y-22 ... second separation electrode, 21Y-13 ... third separation electrode, 21Y-14 ... fourth separation electrode, 23 ... 2nd alignment film, 25 ... Dielectric layer, 31Y ... Cylindrical lens.

Claims (9)

A display panel for two-dimensional image display;
A first electrode, a second electrode disposed to face the first electrode, and a liquid crystal layer disposed between the first electrode and the second electrode, By changing the refractive index distribution in the liquid crystal layer according to the voltage applied by the first electrode and the second electrode, the lens effect on the display image light from the display panel is turned on and off. A lens array element configured to be variably controllable to a state, and
In the lens array element, either one of the first electrode and the second electrode has a plurality of the predetermined electrodes so that the lens effect can be turned on / off for each of the plurality of predetermined partial regions. A stereoscopic display device that is electrically separated into partial areas and is capable of applying a voltage to the liquid crystal layer for each of the predetermined partial areas. A display panel for displaying images,
A first electrode, a second electrode disposed to face the first electrode, and a liquid crystal layer disposed between the first electrode and the second electrode, A lens array element configured to control a lens effect on display image light from the display panel according to a voltage applied by the first electrode and the second electrode;
Either one of the first electrode and the second electrode is electrically separated into a plurality of predetermined partial regions, and a voltage can be applied to the liquid crystal layer for each of the predetermined partial regions A 3D display device with a structure. A display panel for displaying images,
A first electrode, a second electrode disposed to face the first electrode, and a liquid crystal layer disposed between the first electrode and the second electrode, A lens array element configured to be able to control a direction of refractive power with respect to display image light from the display panel in accordance with a voltage applied by the first electrode and the second electrode. ,
Either one of the first electrode and the second electrode is electrically separated into a plurality of predetermined partial regions, and a voltage can be applied to the liquid crystal layer for each of the predetermined partial regions A 3D display device with a structure. In the lens array element, the lens effect is set to an off state for all of the plurality of predetermined partial areas, and the display image light from the display panel is transmitted without being refracted, so that the two-dimensional display on the entire screen And
In the lens array element, the lens effect is set to an on state for all of the plurality of predetermined partial areas, and the display image light from the display panel is refracted so as to enable stereoscopic viewing, so that the entire screen is obtained. 3D display of
In the lens array element, the lens effect is set to an on state for a partial area of the plurality of predetermined partial areas, and the display image light from the display panel is refracted so as to enable stereoscopic viewing. By performing the three-dimensional display in the partial area, the lens effect is set to the off state for the other partial areas, and the display image light from the display panel is transmitted without being refracted. The stereoscopic display device according to claim 1, wherein two-dimensional display is performed in the other partial area. The first electrode is a planar electrode as a whole,
The second electrode includes a plurality of line electrodes extending in a vertical direction and spaced from each other, and a predetermined common voltage is applied to the plurality of line electrodes as a whole.
5. The planar electrode includes a plurality of divided electrodes corresponding to the plurality of predetermined partial regions, and a predetermined driving voltage is applied to each of the plurality of divided electrodes. The stereoscopic display device according to any one of the above. The first electrode is a planar common electrode to which a predetermined common voltage is applied to the whole,
The second electrode includes a plurality of line electrodes extending in a vertical direction and spaced apart from each other,
The plurality of line electrodes are electrically separated for each of the plurality of predetermined partial regions, and a predetermined driving voltage is applied to each of the plurality of predetermined partial regions. 5. The stereoscopic display device according to claim 4. 5. The lens array element generates a lens effect equivalent to a plurality of cylindrical lenses arranged in parallel in the horizontal direction in a region where the lens effect is set to an on state. The stereoscopic display device according to item. The stereoscopic display device according to claim 1, wherein each of the plurality of predetermined partial areas has the same area size. As the plurality of predetermined partial areas, a first partial area and one or more second partial areas having a smaller area size than the first partial area,
In the lens array element, the first partial area is set as the partial partial area for three-dimensional display, and the second partial area is set as the other partial area for two-dimensional display. The stereoscopic display device according to claim 4.

Images