JP5041258B2 - Aerial image display device - Google Patents

Description

  The present invention relates to an apparatus that performs three-dimensional display by displaying an aerial image, and more particularly to an aerial image display apparatus that includes at least a two-dimensional display device and a lenticular lens.

  2. Description of the Related Art Conventionally, a binocular stereoscopic display device that realizes stereoscopic viewing by showing an image with parallax to both eyes of an observer is known. On the other hand, binocular parallax, convergence, physiological adjustment, and motion parallax are known as three-dimensional perception functions of humans, but the binocular parallax satisfies binocular parallax, but with other perception functions Often there are discrepancies or contradictions between them. These discrepancies and contradictions are not possible in the real world, so it is said that the brain is confused and causes fatigue.

  Therefore, development of an aerial image method is underway as a method for realizing more natural stereoscopic vision. In the aerial image method, a plurality of light beams having different emission directions are emitted into the space to form an aerial image corresponding to a plurality of viewing angles. The aerial image method can satisfy binocular parallax, convergence, and motion parallax among the stereoscopic perception functions of humans. In particular, if a suitable image can be displayed in the space for a very finely divided viewing angle, all stereoscopic perception functions including physiological adjustment, which is a human focus adjustment function, can be satisfied. It is possible to feel a natural stereoscopic image. As a method for forming an aerial image, a “time division method” display method is known in which images corresponding to a plurality of viewing angles are displayed by switching at high speed in a time division manner. As what implement | achieves a time division system, the thing using the micro deflection | deviation mirror array produced, for example using the MEMS (Micro Electro Mechanical System) technique is known. In this method, time-divided image light is deflected in synchronism with image switching timing by a micro deflection mirror array.

  As an aerial image method, a method in which a two-dimensional display device such as a liquid crystal display and a lenticular lens are combined is known (see Non-Patent Documents 1 and 2 and Patent Documents 1 and 2). In this method, images corresponding to a plurality of viewing angles are simultaneously packed in one display surface of a two-dimensional display device and displayed at the same time, and images corresponding to the plurality of viewing angles are appropriately displayed via a lenticular lens. A spatial image corresponding to a plurality of viewing angles is formed by deflecting and radiating in various directions. Unlike the above-described time division method, this is called a “surface division method” because images corresponding to a plurality of viewing angles are divided and displayed at the same time in one display surface.

  Here, the lenticular lens is configured by arranging a plurality of cylindrical lenses (cylindrical lenses) in parallel so that the cylindrical axes (center axes) of the lenticular lenses are substantially parallel to each other, and is configured in a sheet shape (plate shape) as a whole. is there. In the above-described surface division method, the focal plane of the cylindrical lens constituting the lenticular lens is arranged so as to coincide with the display surface of the two-dimensional display device. As the simplest combination method of the two-dimensional display device and the lenticular lens, there is a method of setting the cylindrical axis of the cylindrical lens and the vertical direction of the two-dimensional display device in parallel. In the case of this method, the display surface of the two-dimensional display device is usually composed of a large number of pixels arranged in the horizontal direction (lateral direction) and the vertical direction (longitudinal direction), so a predetermined number arranged in the horizontal direction. A “three-dimensional pixel” is configured by associating one cylindrical lens with the plurality of pixels. A “three-dimensional pixel” is one unit of pixels for displaying an aerial image, and a pixel group including a predetermined number of pixels of a two-dimensional display device is set as one “three-dimensional pixel”. . Since the horizontal distance from the cylindrical axis of the cylindrical lens to each pixel determines the horizontal traveling direction (deflection angle) of the light emitted from the pixel after passing through the cylindrical lens, it is the same as the number of horizontal pixels used as a three-dimensional pixel. The horizontal display direction can be obtained. In this configuration method, it is pointed out that if the horizontal display direction is increased, the horizontal resolution of the three-dimensional display is extremely lowered, and the horizontal and vertical resolutions of the three-dimensional display are unbalanced. In order to solve this problem, Patent Document 1 proposes a method in which the cylindrical axis of a cylindrical lens is arranged to be inclined with respect to the vertical direction of the two-dimensional display device.

FIG. 19A shows an example of the display method proposed in Patent Document 1. In FIG. 19A, the two-dimensional display device 101 includes a plurality of pixels 102 of three colors of R, G, and B. The pixels 102 are arranged so that the same color is arranged in the vertical direction, and the three colors R, G, and B appear periodically in the horizontal direction. The lenticular lens 103 has a plurality of cylindrical lenses 104. The lenticular lens 103 is arranged to be inclined with respect to the vertical arrangement direction of the pixels 102. In this display method, a total of M × N pixels 102 (M in the horizontal direction and N in the vertical direction) constitute one three-dimensional pixel to realize M × N horizontal display directions. At this time, if the inclination angle of the lenticular lens 103 is θ,
By setting θ = tan ⁻¹ (px / Npy), the horizontal distance with respect to the cylindrical axis of the cylindrical lens 104 can be set to different values for all the pixels 102 in the three-dimensional pixel. Here, px is the horizontal pitch of the pixels 102 of each color, and py is the vertical pitch of the pixels 102 of each color.

  In the example of FIG. 19A, assuming that N = 2 and M = 7/2, one three-dimensional pixel is configured by using seven pixels 102, and seven horizontal display directions are realized. In FIG. 19A, the numbers 1 to 7 assigned to the pixels 102 correspond to the seven horizontal display directions. By tilting the lenticular lens 103 in this way, not only the horizontal pixel 102 but also the vertical pixel 102 can be used to form one three-dimensional pixel, and the horizontal direction of the three-dimensional display. It has been proposed that the reduction in resolution can be suppressed and the balance between horizontal and vertical resolutions can be improved.

  However, in the display method shown in FIG. 19A, only one color pixel 102 corresponds to one three-dimensional pixel in one horizontal display direction. Therefore, the three primary colors R, G, and B cannot be displayed simultaneously in one horizontal display direction within one three-dimensional pixel. Therefore, by combining three three-dimensional pixels, three primary colors of R, G, and B are displayed in one horizontal display direction. In FIG. 19B, the display color in the fourth horizontal display direction among the seven horizontal display directions is shown for each three-dimensional pixel. As shown in FIG. 19B, by using a combination of three three-dimensional pixels in an oblique direction, the three primary colors R, G, and B are simultaneously displayed in one horizontal display direction, thereby realizing a full color display. . In this display method, since the display color of the three-dimensional pixel changes depending on the horizontal display direction, a problem has been pointed out that color unevenness occurs in the three-dimensional image. Furthermore, since the maximum intensity changes with respect to the horizontal display direction depending on the pixel structure of the pixel 102 of each color, there is also a problem that unevenness in the horizontal direction occurs in the retinal image. Patent Document 2 proposes a method for improving the problems caused by the display method described in Patent Document 1 described above by devising the arrangement of the pixels 102 and the tilt angle θ of the lenticular lens 103.

US Pat. No. 6,064,424 JP-A-2005-309374

Yuzo Hirayama, “Flat Display Type 3D Display System”, Optics, Vol. 35, 2006, p. 416-422 Y. Takaki, “Density directional display for generating natural three-dimensional images”, Proc. IEEE, 2006, Vol. 94, p. 654-663

  However, the conventional aerial image display device using the time division method has a problem that it is difficult to realize a large-area display device in terms of cost and manufacturing suitability. In addition, for example, when a micro deflection mirror array is used, in order to synchronize and deflect all micro mirrors with high accuracy, it is necessary to control each micro mirror independently with very high accuracy. There is a problem that it is difficult.

  In addition, the conventional aerial image display device using the surface division method is characterized in that three-dimensional information (images corresponding to a number of viewing angles) is simultaneously packed in the display surface of the two-dimensional display device. Since the three-dimensional information is packed into the limited number of pixels of the two-dimensional display device, the definition of the displayed three-dimensional image (spatial image) is always a two-dimensional image that can be displayed by the two-dimensional display device. It will be inferior to the definition of. Moreover, if you think that you want to increase the viewable area of the aerial image, or if you want to display a natural and smooth aerial image with respect to the movement of the viewer, the resolution is that of the two-dimensional display device There is a problem that it is extremely deteriorated compared to the definition. To avoid this, instead of packing all of the 3D information into the 2D display device at once, the 2D display uses 3D information that is slightly different by using the integration effect of the human eye. A method of displaying the image of the apparatus in a time division manner while switching at high speed is conceivable. This can be said to be a display method that combines a time-division method and a surface-division method, but no concrete method has been developed yet for practically realizing it.

  The present invention has been made in view of such problems, and an object of the present invention is to provide a spatial image display device capable of easily realizing high-definition stereoscopic display as compared with the conventional art.

  The aerial image display device of the present invention is a spatial image display device that forms a three-dimensional aerial image by emitting a plurality of light beams corresponding to a plurality of viewing angles into the space, and has a p color (p is 1). A plurality of pixels of the above integer), and each pixel is two-dimensionally arranged on the vertical and horizontal grids orthogonal to each other (substantially orthogonal) to form a flat display surface, and A two-dimensional display unit in which a plurality of pixels of the same color are arranged in the vertical direction and a plurality of p-color pixels are periodically arranged so that the same color appears in a certain period in the horizontal direction, and a plurality of cylindrical lenses The cylindrical axes are arranged in parallel so that their cylindrical axes are parallel (substantially parallel), and are configured in a plate shape as a whole, and are arranged so as to be parallel (substantially parallel) as a whole with respect to the display surface of the two-dimensional display unit. In addition to the cylindrical axis with respect to the vertical axis of the two-dimensional display A lenticular lens arranged so that the cylindrical axis of the lens is inclined at a predetermined angle in a plane parallel (substantially parallel) to the display surface, and deflects and emits display image light from the two-dimensional display unit for each pixel; By reciprocating at least one of the lenticular lens or the two-dimensional display unit in a plane parallel (substantially parallel) to the display surface, the relative position between each cylindrical lens and each pixel of the two-dimensional display unit is periodically changed. Displacement means for displacing and periodically displacing the radiation direction of the display image light from any pixel by each cylindrical lens, and an image corresponding to one frame of the three-dimensional image for each pixel of the two-dimensional display unit In addition to performing control to display by division, control to synchronize the timing of time-division display on the two-dimensional display unit and the timing to displace the relative position by the displacement means. It is obtained by a control means. As a result, while moving the relative position between the two-dimensional display unit and the lenticular lens, the light of the time-division image of the three-dimensional image synchronized with the displacement operation is transferred from the two-dimensional display unit to the space through the lenticular lens. By radiating, a three-dimensional spatial image corresponding to a plurality of viewing angles is displayed.

  In the aerial image display device of the present invention, by combining a two-dimensional display unit having a plurality of p-color pixels and a lenticular lens arranged obliquely with respect to the pixel array, a plurality of viewing angles can be obtained at the same time. Corresponding light rays are emitted into the space by plane division. In addition, the relative position between each cylindrical lens and each pixel of the two-dimensional display unit is periodically displaced, so that the radiation direction of display image light from any pixel by each cylindrical lens is periodically displaced. An image corresponding to one frame of the 3D video is displayed in a time-sharing manner for each pixel of the 2D display unit, and the timing of the time-division display in the 2D display unit and the relative position by the displacement means The timing of displacing is controlled synchronously. That is, in the aerial image display device of the present invention, stereoscopic display combining the surface division method and the time division method is performed. Thereby, a high-definition stereoscopic display is realized as compared with the conventional case.

In the spatial image display device of the present invention, the pixel pitch for each color in the horizontal direction of the two-dimensional display unit is px, the pixel pitch for each color in the vertical direction is py, and N pixels are arranged in the vertical direction in the two-dimensional display unit. When a total of p × M × N pixels (N and M are integers of 1 or more) composed of p × M pixels in the horizontal direction is defined as “three-dimensional pixels”, in the vertical direction in the two-dimensional display unit. The angle between the parallel line segment and the line segment parallel to the cylindrical axis of the lenticular lens is
θ = tan ⁻¹ {(p · px) / (n · N · py)} (A)
(Where n is an integer greater than 1)
It is preferable that the following relational expression is satisfied. Note that even though this relational expression is not strictly satisfied, it is sufficient that it is generally satisfied within a range in which a target appropriate display quality is satisfied.

In particular, the displacing means reciprocates the lenticular lens or the two-dimensional display unit in a direction parallel (substantially parallel) to the lateral direction of the two-dimensional display unit, and the two-dimensional display unit corresponds to one frame of the three-dimensional image. Are displayed in a time-division manner on m × n images. When n · N is an integral multiple of p in the relational expression (A), the control means includes a lenticular lens and a two-dimensional display unit. The relative reference position in one predetermined direction to x0 is set to x0, and the relative position xij in one predetermined direction between each cylindrical lens and each pixel of the two-dimensional display unit is displaced according to the following relational expression (1). In addition, it is preferable to perform control to synchronize the timing of the time division display in the two-dimensional display unit with the timing of displacement according to the relational expression (1). Accordingly, when m × n images are displayed on the two-dimensional display unit in a time-sharing manner, each cylindrical lens and each pixel of the two-dimensional display unit are displayed in each state in which m × n images are displayed. The relative positions in one predetermined direction are different from each other. Note that even though this relational expression is not strictly satisfied, it is sufficient that it is generally satisfied within a range in which a target appropriate display quality is satisfied.
xij = x0 + b0 · i + a0 · j
However,
i = 0,..., (m-1) m is an integer of 1 or more j = 0,..., (n-1) n is an integer of 1 or more a0 = p.px / n
b0 = a0 / (N · m)
...... (1)

In particular, when n · N is not an integral multiple of p in the relational expression (A), the control means sets each relative cylindrical position of the lenticular lens and the two-dimensional display unit as x0 as a relative reference position in a predetermined direction. The relative position xij in a predetermined direction between the lens and each pixel of the two-dimensional display unit is displaced according to the following relational expression (2), and the timing of time-division display in the two-dimensional display part is expressed by the relational expression ( It is preferable to perform control synchronized with the timing of displacement according to 2). Accordingly, when m × n images are displayed on the two-dimensional display unit in a time-sharing manner, each cylindrical lens and each pixel of the two-dimensional display unit are displayed in each state in which m × n images are displayed. The relative positions in one predetermined direction are different from each other. Note that even though this relational expression is not strictly satisfied, it is sufficient that it is generally satisfied within a range in which a target appropriate display quality is satisfied.
xij = x0 + b0 · i + a0 · j
However,
i = 0,..., (m-1) m is an integer of 1 or more j = 0,..., (n-1) n is an integer of 1 or more a0 = (p · px) / n
b0 = px
m = p
(2)

  By performing appropriate control so as to satisfy such a predetermined relational expression, brightness intensity unevenness and color unevenness of the aerial image are suppressed, and a better aerial image display can be performed.

  According to the aerial image display device of the present invention, a two-dimensional display unit having a plurality of p-color pixels and a lenticular lens arranged obliquely with respect to the pixel array are appropriately combined to obtain a plurality of viewing angles by plane division. A plurality of corresponding light beams are radiated into the space, and the relative positions of the cylindrical lenses of the lenticular lens and the pixels of the two-dimensional display unit are periodically displaced, and from any pixel by the cylindrical lenses, The emission direction of the display image light is periodically displaced, and an image corresponding to one frame of the three-dimensional video is displayed in a time-sharing manner for each pixel of the two-dimensional display unit, and time-division display in the two-dimensional display unit Since the timing and the timing for displacing the relative position are synchronously controlled, it is possible to realize a three-dimensional display combining the surface division method and the time division method. In addition, since the time-division display is realized by moving the lenticular lens or the two-dimensional display unit as a whole, for example, when individual micromirrors of the micro deflection mirror array are independently controlled in a time-division manner. Compared to the above, synchronous control is also facilitated. Thereby, it is possible to easily realize a high-definition stereoscopic display as compared with the conventional case.

It is the external view which showed schematic structure of the aerial image display apparatus which concerns on the 1st Embodiment of this invention with the state of the light ray radiated | emitted from one three-dimensional pixel. It is explanatory drawing which shows the state which looked at the light beam shown in FIG. 1 from upper direction. 1 is a block diagram showing an overall configuration of a spatial image display device according to a first embodiment of the present invention. It is a schematic diagram for demonstrating an example of the production method of a video signal. It is explanatory drawing which shows the structural column of the pixel of the two-dimensional display part in the aerial image display apparatus which concerns on the 1st Embodiment of this invention, and the example of arrangement | positioning of a lenticular lens. It is explanatory drawing which showed the operation example of the relative movement of a two-dimensional display part and a lenticular lens by time division within a three-dimensional 1 frame period paying attention to a red pixel. It is the bird's-eye view (A) and side sectional view (B) for demonstrating the deflection angle of the light ray from arbitrary light emission points (pixel). It is explanatory drawing about distance xs of arbitrary light-emitting points and the line Y 'which projected the centerline (cylindrical axis) Y1 of the cylindrical lens on the display surface. It is a bird's-eye view for demonstrating the relationship between the deflection angles (phi) and (phi) 'of a light ray. It is a figure for demonstrating the relationship between the deflection angles (phi) and (phi) 'of a light ray, (A) is the top view which looked at the light ray from the direction (Z direction) perpendicular | vertical to a display surface, (B) is a light ray of a display surface. The side view seen from the vertical direction (Y direction), (C) is the side view seen from the central axis direction (Y ′ direction) of the cylindrical lens. FIG. 7 is an explanatory diagram showing the display state at timing T9 in FIG. 6 in more detail. It is explanatory drawing which shows the 1st example of the relationship between the relative displacement amount of the two-dimensional display part and lenticular lens for implement | achieving the operation | movement shown in FIG. 6, and the timing of the relative movement. It is explanatory drawing which shows the 2nd example of the relationship between the relative displacement amount of the two-dimensional display part for implement | achieving the operation | movement shown in FIG. 6, and the lenticular lens, and the timing of the relative movement. It is explanatory drawing which shows that a color nonuniformity is suppressed. It is explanatory drawing which expanded and showed the display state in timing T1, T4, and T7 in FIG. It is explanatory drawing which expanded and showed the display state in timing T2, T5, and T8 in FIG. It is explanatory drawing which expanded and showed the display state in timing T3, T6, and T9 in FIG. It is explanatory drawing which shows the example of a display of the aerial image display apparatus which concerns on the 2nd Embodiment of this invention. (A) is a top view which shows an example of the conventional three-dimensional display apparatus which combined the two-dimensional display apparatus and the lenticular lens, (B) is explanatory drawing which shows the state of the pixel displayed in a certain one display direction.

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

  FIG. 1 shows a schematic configuration of the appearance of the aerial image display device according to the first embodiment of the present invention. FIG. 1 also shows the state of light rays emitted from a certain pixel (three-dimensional pixel 11). FIG. 2 shows the light beam as viewed from above. FIG. 3 shows the overall configuration of the aerial image display apparatus according to the present embodiment, including circuit elements.

  The aerial image display device according to the present embodiment includes a two-dimensional display device and a lenticular lens 2. The two-dimensional display device includes a two-dimensional display unit 1 including a display device such as a liquid crystal display panel. The lenticular lens 2 is configured in a plate shape as a whole by arranging a plurality of cylindrical lenses 2A in parallel so that their cylindrical axes are substantially parallel to each other. The lenticular lens 2 is disposed so as to be substantially parallel to the display surface 1A of the two-dimensional display unit 1 as a whole. The cylindrical lenses 2 </ b> A are disposed so as to face each other so that the focal plane of each cylindrical lens 2 </ b> A coincides with the display surface 1 </ b> A of the two-dimensional display unit 1. The lenticular lens 2 is arranged such that the cylindrical axis of the cylindrical lens 2 </ b> A is inclined with respect to the vertical direction (Y direction) of the two-dimensional display unit 1. The lenticular lens 2 deflects and emits display image light from the two-dimensional display unit 1 for each pixel.

  The two-dimensional display unit 1 has a plurality of p types (p colors (p is an integer of 1 or more)) of pixels 10, and each pixel 10 has a vertical direction (Y direction) and a horizontal direction (X direction) that are substantially orthogonal to each other. The flat display surface 1A is formed by two-dimensionally arranging on the grid. The two-dimensional display unit 1 also has a plurality of pixels 10 of the same color arranged in the vertical direction and a plurality of p-color pixels 10 arranged periodically so that the same color appears in a certain period in the horizontal direction. . As such a two-dimensional display unit 1, for example, a liquid crystal display device can be used. The liquid crystal display device has a structure (not shown) in which a pixel electrode formed in each pixel 10 is sandwiched between a pair of glass substrates. A liquid crystal layer (not shown) is further provided between the pair of glass substrates.

FIG. 5 more specifically shows a configuration column of the pixels 10 of the two-dimensional display unit 1 and an arrangement example of the lenticular lens 2. The two-dimensional display unit 1 and the lenticular lens 2 are a line segment (line segment parallel to the Y direction) passing through the center of the column formed by the pixels 10 of the same color of the two-dimensional display unit 1 and the cylindrical axis of the lenticular lens 2. The angle formed by the line segment parallel to Y1 is
θ = tan ⁻¹ {(p · px) / (n · N · py)} (A)
(Where n is an integer greater than 1)
Are arranged so as to satisfy the relational expression (A). Note that even though this relational expression is not strictly satisfied, it is sufficient that it is generally satisfied within a range in which a target appropriate display quality is satisfied.

In the example of FIG. 5, the pixel 10 of the two-dimensional display unit 1 includes four types of pixels 10R, 10G1, 10G2, and 10B (R: red, G1: green 1, G2: green 2, B: blue). Therefore, p = 4 in the relational expression (A). In the example of FIG. 5, dividing green into two types of pixels 10G1 and 10G2 is for the purpose of expanding the color gamut, but of course, the usual three primary colors (R, G, B) and three types of pixels 10R, 10G , 10B alone. However, for three primary colors, p = 3. In relational expression (A), n is particularly preferably an integer of 2 or more only when p = 3. In the relational expression (A), px indicates the pixel pitch for each color in the horizontal direction (X direction) of the two-dimensional display unit 1, and py indicates the pixel pitch for each color in the vertical direction (Y direction). N is the number of pixels in the Y direction included in one three-dimensional pixel 11. A “three-dimensional pixel” is one unit of pixels for displaying an aerial image, and a pixel group composed of a predetermined number of pixels in the two-dimensional display unit 1 is set as one “three-dimensional pixel”. The More specifically, a total of p × M × N pixels (N and M are integers of 1 or more) composed of N pixels 10 in the vertical direction and p × M pixels 10 in the horizontal direction are “ It is set as “three-dimensional pixel”. And, the number of different rays ν ₀ in the radiation direction emitted from one three-dimensional pixel 11 at the same time is
ν ₀ = p · M · N
Satisfied. In the example of FIG. 5, N = 4 is set in the vertical direction and M = 4 is set in the horizontal direction. In relational expression (A), n is an arbitrary integer, but once determined, it cannot be changed in the system of the same aerial image display device. In the example of FIG. 5, n = 2. In the present embodiment, there is no particular restriction on the shape of the lenticular lens 2, but there is only one restriction. That is, the pitch of the lenticular lens 2 is equal to the length of the three-dimensional pixel 11 in the X direction. That is, the pitch pr in the X direction of each cylindrical lens 2A in the lenticular lens 2 is
pr = p, px, M
It is a value that satisfies. Note that even though this relational expression is not strictly satisfied, it is sufficient that it is generally satisfied within a range in which a target appropriate display quality is satisfied.

  The aerial image display device according to the present embodiment reciprocates at least one of the lenticular lens 2 or the two-dimensional display unit 1 in a plane substantially parallel to the display surface 1A, so that each cylindrical lens 2A and the two-dimensional display unit are moved. Displacement means is provided for periodically displacing the relative position of each pixel 10 to each pixel 10 and periodically displacing the radiation direction of display image light from any pixel 10 by each cylindrical lens 2A. In addition, control is performed to display an image corresponding to one frame of the three-dimensional video for each pixel 10 of the two-dimensional display unit 1 in a time division manner, and the timing of the time division display in the two-dimensional display unit 1 and the displacement means Control means for performing control to synchronize with the timing of displacing the relative position is provided.

  FIG. 3 shows circuit elements for performing the control. As shown in FIG. 3, this aerial image display device includes an X driver (data driver) 33 that supplies a driving voltage based on a video signal to each pixel 10 in the two-dimensional display unit 1, and the two-dimensional display unit 1. A Y driver (gate driver) 34 that drives each pixel 10 along a scanning line (not shown), a timing control unit (timing generator) 31 that controls the X driver 33 and the Y driver 34, A video signal processing unit 30 (signal generator) that processes a video signal to generate a time-division video signal, and a video memory 32 that is a frame memory for storing the time-division video signal from the video signal processing unit 30 are provided. ing.

  The video signal processing unit 30 generates a time-division video signal that is switched in a time-division manner according to a plurality of viewing angles (deflection angles) with respect to one subject based on a video signal supplied from the outside, and supplies the video memory 32 with the time-division video signal. To supply. Further, the video signal processing unit 30 sends a predetermined control signal to the timing control unit 31 so that the X driver 33, the Y driver 34, and the piezoelectric element control unit 35 operate in synchronization with the switching timing of the time division video signal. To supply. Note that such a time-division video signal is created in advance by imaging the imaging object 4 to be displayed from various angles (corresponding to viewing angles) as shown in FIG. 4, for example. May be.

  This aerial image display device also includes a piezoelectric element 21 corresponding to a specific example of the “displacement means”. In the example of FIG. 3, the piezoelectric element 21 is provided on the lenticular lens 2, but in this spatial image display device, the relative position between the lenticular lens 2 and the two-dimensional display unit 1 is relatively displaced. Since it only needs to be moved, the piezoelectric element 21 may be provided in the two-dimensional display unit 1. Or you may make it provide in both the lenticular lens 2 and the two-dimensional display part 1. FIG.

The aerial image display device also includes a piezoelectric element control unit 35 for controlling the relative position displacement operation by the piezoelectric element 21. The piezoelectric element control unit 35 supplies a control signal S 1 for relative position displacement operation to the piezoelectric element 21 in accordance with timing control by the timing control unit 31.
Here, the timing control unit 31 and the piezoelectric element control unit 35 correspond to a specific example of the “control means”.

  The piezoelectric element 21 is disposed on the side surface of the lenticular lens 2, for example, and includes a piezoelectric material such as lead zirconate titanate (PZT). The piezoelectric element 21 is displaced so that the relative position between the two-dimensional display unit 1 and the lenticular lens 2 reciprocates along the X-axis direction in the XY plane according to the control signal S1. is there. The details of the relative position displacement operation by the piezoelectric element 21 will be described later.

  Next, the operation of the aerial image display device configured as described above will be described.

  In this spatial image display device, as shown in FIG. 3, based on the time-division video signal supplied from the video signal processing unit 30, the drive voltage (pixel applied voltage) from the X driver 33 and the Y driver 34 to the pixel electrode. Is supplied. Specifically, when the two-dimensional display unit 1 is, for example, a liquid crystal display device, a pixel gate pulse is applied from the Y driver 34 to the gates of TFT elements for one horizontal line in the two-dimensional display unit 1, and X A pixel applied voltage based on the time-division video signal is applied from the driver 33 to the pixel electrode for one horizontal line. As a result, the backlight is modulated by a liquid crystal layer (not shown), and the display image light is emitted from each pixel 10 in the two-dimensional display unit 1. As a result, the two-dimensional display image based on the time-division video signal is converted to the pixel 10. Generated in units.

  The display image light emitted from the two-dimensional display unit 1 is converted into a substantially parallel light beam by the lenticular lens 2 and emitted. At this time, based on the control signal S1 supplied from the piezoelectric element control unit 35, the piezoelectric element 21 changes the relative position between the two-dimensional display unit 1 and the lenticular lens 2 according to switching of the time-division video signal. Displace in the Y plane. For example, the lenticular lens 2 is displaced so as to reciprocate along the X-axis direction. Then, each time the time-division video signal is switched, the relative positional relationship thereof is shifted corresponding to the viewing angle of each. Therefore, the display image light includes information on binocular parallax and the convergence angle, and accordingly, an appropriate parallel light flux of the display image light is emitted according to an angle (viewing angle) viewed by the observer. A desired stereoscopic image is displayed according to the viewing angle.

  In this aerial image display device, video signals (time-division video signals) corresponding to a plurality of viewing angles are switched by time division for one subject. There is no need to include an image corresponding to a plurality of viewing angles (deflection angles) in the three-dimensional image, and image quality deterioration (definition) is minimized as compared with the case of two-dimensional display. Moreover, since it can be manufactured without using a conventional MEMS technique or the like, it can be easily obtained. Furthermore, since a flat display device can be obtained as a whole, a compact (thin) structure is obtained.

  As described above, in the present embodiment, while the relative position between the two-dimensional display unit 1 and the lenticular lens 2 is displaced, a time-division image synchronized with the displacement operation is transferred from the two-dimensional display unit 1 to the lenticular lens 2. One of the features is that the aerial image is displayed by projecting through the screen.

  FIG. 6 shows a timing that serves as a standard for projecting (displaying) a time-division image from the two-dimensional display unit 1. The timing projected from the two-dimensional display unit 1 is set with respect to the relative position between the two-dimensional display unit 1 and the lenticular lens 2. Since it is a relative position, the lenticular lens 2 or the display surface 1A of the two-dimensional display unit 1 may actually move. In the example of FIG. 6, an example is shown in which the display surface 1 </ b> A of the two-dimensional display unit 1 is substantially translated in the horizontal direction (X direction) with respect to the fixed lenticular lens 2. In the example of FIG. 6, the pixel 10 of the two-dimensional display unit 1 includes three primary colors (R, G, B) and three types of pixels 10R, 10G, 10B (p = 3). The three-dimensional pixel 11 is composed of a group of N = 2 pixels in the vertical direction and p × M = 3 × 2 pixels in the horizontal direction.

First, it is assumed that the position x0 of the two-dimensional display unit 1 is one timing at which an image is projected from the two-dimensional display unit 1, as indicated by T1 in FIG.
Then, according to the present embodiment, when n · N is an integral multiple of p in the above relational expression (A), the timing of other positions at which the image is projected from the two-dimensional display unit 1 is Determined based on (1). Note that even though this relational expression is not strictly satisfied, it is sufficient that it is generally satisfied within a range in which a target appropriate display quality is satisfied.
xij = x0 + b0 · i + a0 · j
However,
i = 0,..., (m-1) m is an integer of 1 or more j = 0,..., (n-1) n is an integer of 1 or more a0 = p.px / n
b0 = a0 / (N · m)
...... (1)

When n · N is not an integral multiple of p in the relational expression (A), the timing of other positions at which the image is projected from the two-dimensional display unit 1 is determined based on the following expression (2). . Note that even though this relational expression is not strictly satisfied, it is sufficient that it is generally satisfied within a range in which a target appropriate display quality is satisfied.
xij = x0 + b0 · i + a0 · j
However,
i = 0,..., (m-1) m is an integer of 1 or more j = 0,..., (n-1) n is an integer of 1 or more a0 = (p · px) / n
b0 = px
m = p
(2)

  In the present embodiment, when n · N is an integral multiple of p, the control means sets the relative reference position between the lenticular lens 2 and the two-dimensional display unit 1 as x0, and each cylindrical lens 2A and the two-dimensional The relative position xij of the display unit 1 with respect to each pixel 10 is displaced substantially according to the above relational expression (1), and the time division display timing in the two-dimensional display part 1 is changed to the timing of displacement according to the relational expression (1). Control to synchronize. When n · N is not an integral multiple of p, control based on the relational expression (2) is performed instead of the relational expression (1).

  In FIG. 6, taking the case of the relational expression (1) as an example, the timing of other positions at which the image is projected from the two-dimensional display unit 1 including the relative position of x0, that is, the expression (1) is expressed by the expression (1). 1) i and j are summarized in tabular form in an easy-to-understand manner. The position of the two-dimensional display unit 1 at each i and j is fixed with the position of the lenticular lens 2 and the position of the lenticular lens 2 as a reference. It is shown. The example of FIG. 6 is an example when p = 3, m = n = 3, and N = M = 2. Since m = n = 3, i = 0, 1, 2 and j = 0, 1, 2 are obtained. As a result, the table has 3 rows and 3 columns.

  The merit of projecting an image from the two-dimensional display unit 1 at such relative position timing will be described. Before that, as basic knowledge for easy understanding, the display surfaces of the lenticular lens 2 and the two-dimensional display unit 1 are explained. The relationship between the relative position with respect to one light emitting point P1 on 1A and the deflection direction of the light beam projected from the light emitting point P1 will be described.

As shown in FIGS. 7A and 7B, when the light emitting point P1 is arranged at the position of the focal length (effective focal length: f) of the lenticular lens 2 (the cylindrical lens 2A), the light is emitted from the light emitting point P1. In the direction perpendicular to the center line Y1 of the lenticular lens 2 (cylindrical axis of the cylindrical lens 2A), a substantially strip-shaped light beam is emitted in the direction of the deflection angle φ ′. Now, when the projection line of the central axis of the lenticular lens 2 is projected onto the Y′-Xs plane where the emission point P1 is located (that is, the display surface 1A of the two-dimensional display unit 1), the projection line Y is projected from the emission point P1. Assuming that the distance to “xs” is xs, the tangent of the deflection angle φ is approximately expressed by the following equation (3).
tan φ ′ = xs / f (3)

  From this equation (3), it can be seen that the tangent of the deflection angle φ ′ is proportional to the distance xs from the light emitting point P1 to the line Y ′ projected from the center line Y1 onto the light emitting point surface. FIG. 8 illustrates this xs in an easy-to-understand manner. In the present embodiment, the pixels 10 of the two-dimensional display unit 1 are arranged in a grid in the X and Y directions, and the central axis Y1 of the lenticular lens 2 is arranged at an angle θ with respect to the Y axis. The Xs axis is arranged in a direction perpendicular to the central axis Y1 (projection line Y ′) of the lenticular lens 2 as shown in FIG. 8, and the origin O is a point where the center line of the lenticular lens 2 and xs intersect. Is arranged. In this way, it can be seen that the distance xs from each pixel 10 to the center line Y1 of the lenticular lens 2 is the distance from each pixel to the perpendicular line down to the Xs axis and the origin O on the Xs axis. The value of xs is proportional to the tangent of the deflection angle φ ′.

  Incidentally, since the deflection angle φ of interest in the present embodiment is an angle formed by the light beam propagating in the X-axis direction and the axis Z perpendicular to the display surface 1A of the two-dimensional display unit 1, φ is φ ′ It is necessary to describe using. The relationship between φ and φ ′ will be described with reference to FIGS. 9 and 10A to 10C. First, the display surface 1A of the two-dimensional display unit 1 is arranged on the XY plane so that the lattices of the lattice-like pixels 10 of the two-dimensional display unit 1 coincide with the X and Y axis directions, respectively. On top of this, the lenticular lens 2 is arranged such that the center line of the lenticular lens 2 forms an angle θ with the Y axis.

In the bird's eye view of FIG. 9, the direction lines (projection line Y ′) of the Y and X axes and the central axis Y1 of the lenticular lens 2 are entered. Consider the case where light from the pixel 10 at the origin O among the pixels 10 of the two-dimensional display unit 1 is emitted through the lenticular lens 2. The emission surface 50 shown in FIG. 9 is the shape of a light beam emitted from the pixel 10 at the origin O. The shape of the radiation surface 50 shown in FIG. 9 is a plate-shaped rectangle, and one side of the rectangle matches the line segment (Y ′) in the center line direction of the lenticular lens 2 passing through the origin O. In this state, the rectangular surface is arranged so as to be inclined by φ from the Z axis perpendicular to the XY plane. At this time, what is desired is to calculate the angle φ between the light beam emitted in the direction along the X axis from the origin O in the direction along the X axis and the Z axis, and the sky above the Xs axis from the origin O along the Xs axis. This is the relationship between the angle φ ′ formed by the light beam radiated in the selected direction and the Z axis. FIG. 10A is a top view of the bird's eye view of FIG. 9 viewed from directly above in the Z-axis direction. The height from the Xs axis when a ray radiated from the origin O and propagates along the Xs axis over the Xs axis propagates by xs along the Xs axis is
xs / tanφ '
It becomes.

Therefore, the height from the X-axis when the light beam radiated from the origin O and propagates along the X-axis over the X-axis propagates by x along the X-axis is the side surface of FIGS. 10B and 10C. As you can see from the diagram,
(Xs · cos θ) / tanφ ′
It becomes. From this, the relationship between φ and φ ′ is
tanφ = tanφ ′ / cosθ

Also, know the relationship between tangent of φ and xs,
tan φ = xs · {1 / (f · cos θ)} (4)
Since the relationship with x is x = xs · cos θ,
tan φ = x · {1 / (f · cos ² θ)} (5)
That is, it can be seen that the tangent of φ is proportional to x and xs. This completes the explanation of basic knowledge for easy understanding.

  Returning to the main point, based on the basic knowledge described above, the merit of projecting an image from the two-dimensional display unit 1 at the relative position timing as shown in Expression (1) will be described with reference to FIG. .

  Again, in FIG. 6, the image is projected from the two-dimensional display unit 1 including the relative position of x0, taking the case of the expression (1) as an example (that is, when n · N is a multiple of p). In other words, the timing of other positions, that is, the formula (1) is summarized in a tabular form with respect to i and j in the formula (1), and the position of the two-dimensional display unit 1 at each i and j is expressed as follows: The position of the lenticular lens 2 is fixed, and the position of the lenticular lens 2 is shown as a reference. The example of FIG. 6 is an example when p = 3, m = n = 3, and N = M = 2. Since m = n = 3, i = 0, 1, 2 and j = 0, 1, 2 are obtained. As a result, the table has 3 rows and 3 columns.

  In the present embodiment, the order of i and j is not particularly limited, but a predetermined image is projected from the two-dimensional display unit 1 under the same conditions under the same timing conditions at the relative positions in the case of all i and j. It is desirable that In FIG. 6, as can be seen from the figure, each i and j is scanned (relative position is displaced) in the vertical direction (i = 0, 1, 2) sequentially from one column (T1 → T2 →. .. → T9). At this time, paying attention to the “R pixel 11R” included in one arbitrary “three-dimensional pixel” 11, the distance between the pixel 10 and the central axis Y1 of the lenticular lens 2 is stored on the Xs axis for each scan. However, a plot of bar marks is also added to FIG. When all cases are scanned, the final result is T9. FIG. 11 shows the state at the timing T9 in FIG.

As can be seen from FIG. 11, according to the conditional expression (1) according to the present embodiment (equation (2) is also equivalent), an arbitrary “three-dimensional pixel” 11 of the pixel 10 of interest (here, The distance relationship between the R pixel 10R) and the central axis Y1 of the lenticular lens 2 is equal to the width xw on the Xs axis (Δxw)
It can be seen that (N, M, m, n) are lined up.

If the distance relationship from the central axis Y1 of the lenticular lens 2 is arranged at equal intervals on the Xs axis, as can be seen from the equation (4), the tangent of the deflection angle φ is proportional to xs. It can be seen that the tangents are also arranged at equal intervals as a result of the scan. In other words, if an image is projected from the two-dimensional display unit 1 at a timing determined in the present embodiment, a certain type of pixel 10 (here, any “three-dimensional pixel” configured on the arbitrary two-dimensional display unit 1) Then, the tangents of the deflection angles φ of the light rays projected from the R pixel 10R) are equally spaced,
It can be seen that only (N · M · m · n) books are arranged. This is generated by one three-dimensional pixel 11 having a different number of rays ν in the radiation direction radiated from one 3D pixel 11 in one frame period of 3D image display, or in one frame period of 3D image display. This corresponds to the number of viewpoints ν.

This is illustrated in FIG. 1 and FIG. 1 and 2 show the state of light rays emitted from a certain type of pixel 10 (for example, R pixel 10R) of an arbitrary three-dimensional pixel 11 of the aerial image display device. It is assumed that the aerial image is viewed at an arbitrary distance L from the aerial image display device (on the X′-Y ″ plane), and the viewer can freely move in parallel with the screen while maintaining the distance L. (For ease of explanation, the viewer can move only to the left and right while maintaining the distance L for convenience. However, since the distance L is arbitrary, of course, after this explanation, the viewer can You can go to and watch.) Considering a line (Z axis) perpendicular to the center line Y1 of the lenticular lens 2 and the display surface 1A of the two-dimensional display unit 1, a point intersecting the display surface 1A of the two-dimensional display unit 1 and a line on which the viewer moves Let O and O ′ be the points where the two intersect. When a certain type of pixel 10 (for example, R pixel 10R) of the “three-dimensional pixel” 11 is caused to emit light at the relative position timing according to the present embodiment, when the lenticular lens 2 is stopped now, as shown in FIG. If the light emitting points are arranged at equal intervals on the X axis, then the tangents of the deflection angle φ are arranged at equal intervals according to the above equation (5). Further, the light beam radiated from the light emitting point P1 at the position of x from O reaches the point expressed by the following equation (6) separated by x 'from O' on the X 'axis which is separated by L of the viewer. . Here, f is the focal length (effective focal length) of the lenticular lens 2 (the cylindrical lens 2A).
x ′ = L · tan φ = x · {L / (f · cos ² θ)} (6)

  As can be seen from the equation (6), when the positions of the light emitting points P1 on the X axis are arranged at equal intervals, the position of the reaching point is reached when the viewer reaches the X ′ axis of the viewer who is separated by a distance L correspondingly. It can be seen that the lines are evenly spaced. Since the brightness when viewed from the viewer is proportional to the number of rays that enter the pupil of the viewer's eye, when the X ′ axis is reached, the positions of the arrival points are also arranged at equal intervals. 'This means that the light intensity is the same regardless of the position on the axis, that is, there is no unevenness in light intensity. Now, for example, the R pixel 10R has been considered, but this consideration can be applied to all types of pixels 10 as well.

  12 and 13 show an example of a scanning method for realizing the relative position timing shown in FIG. According to the present embodiment, there is no particular limitation on the timing order of the formula (1) or the formula (2). Therefore, the timing order is generally determined according to the characteristics and convenience of the scanning system. Moreover, since what is shown by the above formula is the relative positional relationship between the two-dimensional display unit 1 and the lenticular lens 2, the two-dimensional display unit 1 may actually be moved, or the lenticular lens may be moved. 2 may be sufficient. In the example of FIG. 12 and FIG. 13, the case where the lenticular lens 2 is moved is shown.

  In particular, the example of FIG. 12 is an example when the lenticular lens 2 is scanned (relative position is displaced) in the order of timings T1 → T2,... → T9 swung in FIG. In this example, scanning corresponding to one frame period of 3D video display is performed by repeating one cycle T1 to T9. Similarly, the example of FIG. 13 is an example in which the lenticular lens 2 is scanned in the order of the timings T1 → T2,... → T9 swung in FIG. 6, but in this example, T1 → T2, In this example, scanning is performed in the order of .fwdarw.T9, scanning is performed in the opposite direction to T9, T8,... → T1, and the operation is repeated thereafter.

  What can be said characteristically in each example is that the example of FIG. 12 is considered to always select the timing when scanning in one direction, and is suitable when the hysteresis of the scanning system is a concern. However, after scanning in one direction, it is necessary to return at high speed, and a scanning system capable of high speed operation is required. On the other hand, in the example of FIG. 13, since the reciprocating motion of the scan is efficiently used, the necessary minimum scan speed is sufficient and it is suitable for a relatively slow scan system. However, if there is hysteresis in the reciprocating motion, a problem such as double images may occur, and a scanning system with high positional accuracy is required.

As can be seen from FIG. 13 and FIG. 12, the two-dimensional frame interval tr of the two-dimensional display unit 1 (one frame period of two-dimensional video display) is displayed by the aerial image display device with a predetermined number of light beams. If a certain time interval for displaying the aerial image to be displayed, that is, one frame period (three-dimensional frame interval) of three-dimensional video display is t3D,
t3D = q · (m · n · tr) It is desirable that q satisfies an integer relationship of 1 or more. By the way, with respect to x0 in the formula (1) or the formula (2), this is an arbitrary constant since it is a deflection offset. Normally, if it is desired to deflect the display surface symmetrically with respect to the display surface 1A, if the scan amplitude peak is t0, it is desirable to set the offset x0 to about half of t0.

In this embodiment, in order to obtain the number of rays ν (= N · M · m · n) or the number of viewpoints ν, the two-dimensional display unit 1 displays the time-division within one frame period of the three-dimensional video display. The total number g of two-dimensional images to be
g = m · n ≧ 2
It is preferable that the following relational expression is satisfied.

  As described above, in the spatial display device according to the present embodiment, the timing for displacing the relative position between the lenticular lens 2 and the two-dimensional display unit 1 and the timing for displaying the video from the two-dimensional display unit 1 in a time division manner are appropriately set. It was explained that the viewer can appreciate the aerial image without unevenness of the light intensity by controlling to synchronized with.

Next, it will be described that the color unevenness can be suppressed according to the spatial display device according to the present embodiment.
In order to reproduce a desired color using one three-dimensional pixel 11 according to the present embodiment, each color pixel 10 such as R, G, B, R, G1, G2, B or the like has a predetermined value for each color. It is necessary to reach the viewer in a state where light is emitted and mixed colors. As a method of mixing the colors from the pixels 10 of the respective colors, a method of mixing and emitting the pixels 10 of the respective colors in parallel in time, and a pixel of each color serially in a short time using the integration function of the human eye There is a method in which 10 is emitted with a predetermined amount of light and mixed. In the present embodiment, parallel and serial are mainly used together, but the characteristic point for reproducing the desired color by using the three-dimensional pixel 11 to mix the light of the pixels 10 of each color is as follows. When attention is paid to a light ray emitted from a single three-dimensional pixel 11 in a predetermined deflection direction, R, G, B, R, G1, G2, B, etc. are all in the three-dimensional frame interval t3D described above. That is, it is necessary to emit a light beam with a predetermined amount of light in the predetermined deflection direction equally from the pixel 10 of the type.

  According to the present embodiment, when attention is paid to a light beam emitted from a single three-dimensional pixel 11 in a predetermined deflection direction, R, G, B, R, G1, G2, R3, G3, B2, and R, G1, G2, and so on during a three-dimensional frame interval t3D. Light rays are emitted in a predetermined deflection direction with a predetermined light amount equally from all types of pixels 10 such as B, and color unevenness is suppressed. This will be described with reference to FIG. FIG. 14 is basically the same as FIG. Further, the display state at the timings T1, T4, and T7 in FIG. 14 is enlarged and shown in FIG. Further, the display state at timings T2, T5, T8 is shown in FIG. 16, and the display state at timings T3, T6, T9 is shown in FIG.

  Now, assuming that there are three types of pixels 10 such as R, G, and B, rays from all the pixels 10 of R, G, and B are radiated in the direction of the deflection angle of interest within the three-dimensional frame interval t3D. Just do it. For example, paying attention to the deflection angle φ1 shown in FIG. 14, the R pixel 10R is radiated at the timing T1 of the scan constituting one “three-dimensional frame”, the B pixel 10B at the timing T4, and the G pixel 10G at the timing T7. It can be seen that each is emitted (enlarged in FIG. 15).

If attention is paid to the deflection angle φ2, the light is emitted from the B pixel 10B at the timing T2 constituting one “three-dimensional frame”, the G pixel 10G at the timing T5, and the R pixel 10R at the timing T8. (It is shown enlarged in FIG. 16).
If attention is paid to the deflection angle φ3, the light is emitted from the B pixel 10B at the timing T3 constituting one “three-dimensional frame”, the G pixel 10G at the timing T6, and the R pixel 10R at the timing T8. (It is shown enlarged in FIG. 17).

  As shown in the above example, according to the present embodiment, rays are emitted in the predetermined deflection direction equally from all types of R, G, and B pixels 10 during the three-dimensional frame interval. Therefore, uneven color can be suppressed.

As described above, according to the aerial image display device of the present embodiment, the two-dimensional display unit 1 having a plurality of p-color pixels 10, the lenticular lens 2 arranged at an angle with respect to the pixel array, and 2. By appropriately combining, at the same time, a plurality of light beams corresponding to a plurality of viewing angles are emitted into the space by plane division. In addition, the relative position between each cylindrical lens 2A and each pixel 10 of the two-dimensional display unit 1 is periodically displaced, so that the emission direction of the display image light from any pixel 10 by each cylindrical lens 2A is periodic. Is displaced. An image corresponding to one frame of the three-dimensional video is displayed in a time-sharing manner for each pixel 10 of the two-dimensional display unit 1, and the timing of the time-division display in the two-dimensional display unit 1 and the relative by the displacement means The timing for shifting the general position is synchronously controlled. That is, according to the aerial image display device of the present embodiment, it is possible to realize a stereoscopic display that combines the surface division method and the time division method. Further, since the time-division display is realized by moving the lenticular lens 2 or the two-dimensional display unit 1 as a whole, for example, the individual micromirrors of the micro deflection mirror array are controlled synchronously independently in the time division. Compared to the case, the synchronous control becomes easier. Thereby, it is possible to easily realize a high-definition stereoscopic display as compared with the conventional case. Furthermore, by performing appropriate synchronous control that satisfies a predetermined relational expression, unevenness in brightness intensity and unevenness in color of the aerial image are suppressed, and better aerial image display can be performed.
[Second Embodiment]

  Next, a second embodiment of the present invention will be described. In addition, the same code | symbol is attached | subjected to the component substantially the same as the said 1st Embodiment, and description is abbreviate | omitted suitably.

  In the first embodiment, if the example shown in FIG. 14 is observed closely, all of the R, G, and B pixels 10 are located at a noted location of the three-dimensional pixel 11 by a scanning operation (an operation for displacing the relative position). It can be seen that the color unevenness is suppressed by arranging in order. On the other hand, FIGS. 18A and 18B show display examples in the aerial image display device according to the present embodiment. Note that the aerial image display device according to the present embodiment is different only in the scanning operation method, and the basic configuration is the same as that of the aerial image display device in the first embodiment.

  In the present embodiment, one three-dimensional frame is configured in the two states shown in FIGS. Now, focusing on the portion where the deflection angle is φa as an example, in the first state of FIG. 18A, light from the R pixel 10R is emitted, and in the second state of FIG. Light from the pixel 10G and the B pixel 10B is emitted simultaneously. That is, it can be seen that light from each of the R, G, and B pixels 10 is emitted from one three-dimensional pixel 11 at a deflection angle of φa during one “three-dimensional frame”. 18A and 18B is slightly different from the example of FIG. 14, and it can be seen that the R, G, and B pixels 10 are arranged at different locations of the three-dimensional pixel 11. However, if the light is radiated from one three-dimensional pixel 11 in the same direction, colors from the respective pixels can be mixed even if the place in the three-dimensional pixel 11 is different.

  DESCRIPTION OF SYMBOLS 1 ... Two-dimensional display part, 1A ... Display surface (light emission surface), 2 ... Lenticular lens, 2A ... Cylindrical lens, 4 ... Imaging object, 10 (10R, 10G, 10B) ... Pixel, 11 ... Three-dimensional pixel, 21 DESCRIPTION OF SYMBOLS ... Piezoelectric element, 22 ... Spherical lens, 30 ... Video signal processing part, 31 ... Timing control part, 32 ... Video memory, 33 ... X driver, 34 ... Y driver, 35 ... Piezoelectric element control part, 50 ... Radiation surface, P1 ... light emission point, S1 ... control signal, X ... horizontal axis of the two-dimensional display unit, Y ... vertical axis of the two-dimensional display unit, Y1 ... center axis (cylindrical axis) of the lenticular lens, Xs ... of the lenticular lens An axis perpendicular to the central axis (cylindrical axis), Y ′: an axis obtained by projecting the central axis of the lenticular lens onto the display surface of the two-dimensional display unit, L: a distance from the display surface of the two-dimensional display unit to an arbitrary observation position, X '... 2D table A horizontal axis at a distance L from the display surface of the display part, Y ″... A vertical axis at a distance L from the display surface of the two-dimensional display part.

Claims (8)

An aerial image display device that forms a three-dimensional aerial image by emitting a plurality of light rays corresponding to a plurality of viewing angles into the space,
A plurality of pixels of p color (p is an integer of 1 or more) are provided, and each of the pixels is two-dimensionally arranged on a grid in the vertical and horizontal directions orthogonal to each other to form a flat display surface. A two-dimensional display unit in which a plurality of pixels of the same color are arranged in the vertical direction and a plurality of pixels of p color are periodically arranged so that the same color appears in a certain period in the horizontal direction;
A plurality of cylindrical lenses are arranged in parallel so that their cylindrical axes are parallel to each other, are configured in a plate shape as a whole, and are arranged so as to be parallel to the display surface of the two-dimensional display unit as a whole. The cylindrical axis of the cylindrical lens is arranged to be inclined at a predetermined angle in a plane parallel to the display surface with respect to the vertical axis of the two-dimensional display unit, and the display image light from the two-dimensional display unit A lenticular lens that deflects and emits for each pixel;
By reciprocating at least one of the lenticular lens or the two-dimensional display unit in a plane parallel to the display surface, the relative positions of the cylindrical lenses and the pixels of the two-dimensional display unit are periodically changed. Displacement means for periodically displacing the radiation direction of the display image light from any pixel by each cylindrical lens;
Control is performed to display an image corresponding to one frame of the 3D video in a time-sharing manner for each pixel of the 2D display unit, and the timing of the time-division display in the 2D display unit and the relative by the displacement means And a control means for performing control to synchronize with the timing of displacing the general position,
While the relative position between the two-dimensional display unit and the lenticular lens is displaced, light from the time-division image of the three-dimensional image synchronized with the displacement operation is transmitted from the two-dimensional display unit via the lenticular lens. A spatial image display device that displays a three-dimensional spatial image corresponding to a plurality of viewing angles by radiating in. The pixel pitch for each color in the horizontal direction of the two-dimensional display unit is px, the pixel pitch for each color in the vertical direction is py,
In the two-dimensional display unit, a total of p × M × N pixels (N and M are integers of 1 or more) consisting of N pixels in the vertical direction and p × M pixels in the horizontal direction are defined as “three-dimensional. When `` pixel ''
An angle formed by a line segment parallel to the vertical direction in the two-dimensional display unit and a line segment parallel to the cylindrical axis of the lenticular lens is
θ = tan ⁻¹ {(p · px) / (n · N · py)} (A)
(Where n is an integer greater than 1)
And in the relational expression (A), n · N is an integer multiple of p,
The displacement means is configured to reciprocate the lenticular lens or the two-dimensional display unit only in a predetermined direction parallel to the lateral direction of the two-dimensional display unit;
The aerial image display device according to claim 1, wherein the two-dimensional display unit displays an image corresponding to one frame of the three-dimensional video on m × n images in a time division manner. The number of light rays v having different radiation directions emitted from one 3D pixel in one frame period of 3D video display, or the number of viewpoints generated by one 3D pixel in 1 frame period of 3D video display. ν is
ν = m · n · (M · N)
(Where m is an integer greater than or equal to 1)
The aerial image display device according to claim 2, wherein the following relational expression is satisfied. The number of different rays ν ₀ in the radiation direction emitted from one of the three-dimensional pixels at the same time is
ν ₀ = p · M · N
The aerial image display device according to claim 2, wherein the following relational expression is satisfied. In order to obtain the number of rays ν or the number of viewpoints ν, the total number g of images displayed in a time-division manner within one frame period of the three-dimensional video display in the two-dimensional display unit is as follows:
g = m · n ≧ 2
The aerial image display device according to claim 3, wherein the following relational expression is satisfied. The pitch pr in the X direction of each cylindrical lens in the lenticular lens is
pr = p, px, M
The aerial image display device according to claim 2, wherein the aerial image display device satisfies the following requirement. 3. The aerial image display device according to claim 2, wherein in the relational expression (A), only when p = 3, n is an integer of 2 or more. One frame period (two-dimensional frame interval) of the two-dimensional image display in the two-dimensional display unit is tr, and one frame period (three-dimensional frame interval) of the three-dimensional image display for displaying the number of light beams ν is t3D. When
t3D = q · (m · n · tr)
(Where q is an integer greater than or equal to 1)
The aerial image display device according to claim 3, wherein the relationship is satisfied.

Images