JP7477934B1 - 3D imaging device - Google Patents

Abstract

The present invention provides a stereoscopic image device capable of reducing a blind spot in front of a viewpoint in a volume display that rotates a self-luminous display to draw a stereoscopic image. The stereoscopic image device according to one embodiment of the present invention comprises a self-luminous two-dimensional display means 1 having a display panel 1a having a function of displaying an image by self-luminosity, a rotation means for rotating the self-luminous two-dimensional display means 1 around a rotation axis 6 that defines the up-down direction of the self-luminous two-dimensional display means 1 and is located away from the display surface of the self-luminous two-dimensional display means 1, and a control means for changing a voxel image displayed on the self-luminous two-dimensional display means 1 according to the rotation angle of the rotation means, the rotation axis 6 being located at a required small distance behind the display surface of the front display panel 1a.

Description

The present invention relates to, for example, a stereoscopic image display device, and in particular to a volume display type stereoscopic image display device.

There are various display devices that can render 3D images, but Volumetric Display is not a 3D image like 2D displays that incorporate tweaks such as VR (Virtual Reality) or AR (Augmented Reality), but a method that actually renders points called voxels, which are the smallest components of a 3D image, in space. This method renders a 3D image that is the same as the real thing, so there is no error with the real thing when viewed by the human eye, there are no problems such as 3D sickness or out-of-focus, and there are no restrictions on the viewpoint from which the image appears 3D, so a correct 3D image can be seen from any angle of 360 degrees.

Patent Document 1 discloses the basic configuration of a volume display that creates a 3D image by rotating a self-luminous two-dimensional display (hereinafter also referred to as an LED display panel) that has the function of displaying images by self-emitting light around an axis of rotation that coincides with a vertical line passing through the center of the width of the display surface in the up-down direction, and displaying appropriate voxel images at high speed in synchronization with the rotation.

Patent document 2 discloses a volume display that displays a three-dimensional image by projecting light from a projector onto a movable screen.

U.S. Pat. No. 4,160,973 U.S. Pat. No. 6,183,088

The volume display disclosed in Patent Document 1 has a problem in that there is an angular area (hereinafter referred to as a blind spot) where the emitted light for creating a 3D image does not reach the narrow area extending above and below the center of the display width when viewed from the front, resulting in a loss of image, as shown in Figure 3. In addition, there is a problem as to how to improve image quality under conditions where it is difficult to increase the pixel density above the current density.

The present invention is intended to solve the above-mentioned problems of the conventional art, and aims to provide a stereoscopic imaging device that can create a 3D image in a volumetric display that rotates a self-luminous two-dimensional display to create a 3D image with reduced blind spots in front of the viewpoint and improved defects in the front of the viewpoint.

A secondary objective of the present invention is to provide a stereoscopic imaging device capable of producing 3D images that appear to have increased resolution in a volume display that produces 3D images by rotating a self-luminous two-dimensional display.

In order to solve the above problems, the inventors of the present application firstly conducted research into eliminating the blind spot that occurs directly in front of the viewpoint in the volume display disclosed in Patent Document 1, and secondly into improving the resolution of image quality.

First, the inventors of the present application considered that the volume display disclosed in Patent Document 1 is configured such that, when the display surface is viewed from above, as shown in Figure 20, the center of rotation of the panel support 1c coincides with the vertical line in the center of the width of the display surface of the display panel 1a, and that this configuration is related to the occurrence of blind spots in front of the viewpoint in relation to the emission light characteristics of the light-emitting elements (LEDs) of the self-luminous two-dimensional display.

Next, the inventors investigated the emission light characteristics of light-emitting elements (LEDs) in self-luminous two-dimensional displays and the occurrence of blind spots.

Figure 2 is a conceptual diagram showing the emission light characteristics of a light-emitting element (LED). In the figure, 180 degrees is the angle at which the panel is viewed from the front. As shown in the figure, the emission light characteristics of the light-emitting element show a radiation angle dependency in which the maximum amount of emitted light is emitted in a range of approximately 60 degrees from the front of the viewpoint centered at 180 degrees, and as the angle to the side increases outside the front of the viewpoint, the amount of emitted light decreases.

Figure 4(A) shows a state where the angle between the voxels of the display panel and the viewpoint is 0 degrees when the display panel 1a with the configuration shown in Figure 1(A) is viewed from directly above, but the same is true for the display panel with the configuration shown in Figure 20. In Figure 4(A), with the downward direction of the scale 60 in the figure as the viewpoint, the long black bars indicate the LED display panel, and the short lines displayed close to the LED display panel indicate the voxels drawn as the test pattern corresponding to the test pattern display position shown in Figure 1(B) described below. The angle between the voxels of the LED display panel and the viewpoint is 0 degrees, and there is a blind spot where almost no voxels are visible from the viewpoint.

Figure 3 is a cumulative diagram of test patterns that can actually be seen as an image due to the persistence of vision in the human eye when viewed from in front of the viewing point by rotating an LED display panel of the configuration shown in Figure 20 so that test patterns are displayed at positions corresponding to the test pattern display positions shown in Figure 1 (B) described below.

Figure 3 shows a 3D image in which there is a blind spot where almost no voxels are visible from the viewpoint (front of the viewpoint) when the angle between the voxels of the LED display panel and the viewpoint is 0 degrees. In other words, when the display surface of the self-luminous two-dimensional display is rotated 90 degrees from a state directly facing the viewpoint, the emitted light does not reach the narrow portion extending above and below the center of the display width as seen from the front of the viewpoint, resulting in a 3D image in which a predetermined narrow width and a vertical area are missing at the center of the 3D image.

The inventors of the present application have discovered that in a volume display that rotates an LED display panel to create a 3D image, if the display surface of the LED display panel is shifted forward from the center of rotation, the angle it forms with the light-emitting elements when viewed from directly in front of the viewer increases, thereby reducing blind spots.

Specifically, as shown in FIG. 1(A), when the center of rotation 6 is positioned X mm behind the display surface of the display panel 1a (the display surface of the display panel 1a is shifted forward by X mm), and X mm is changed to 0 mm, 2 mm, 4 mm, 6 mm, 8 mm, and 10 mm, when a test pattern is set to be displayed at the test pattern display position shown in FIG. 1(B) in the three-dimensional shape data 230 of FIG. 10 described later and viewed from in front of the viewpoint (when viewed from the bottom of the figure in FIG. 1(B)), the appearance of the test pattern in front of the viewpoint changes as shown in FIG. 5(A)-(F), and also when a test pattern is set to be displayed at the test pattern display position shown in FIG. 1(C) instead of the test pattern in front of the viewpoint displayed in the front area, and the appearance of the test pattern behind the viewpoint displayed in a position symmetrical to the center of rotation 6 changes as shown in FIG. 5(G)-(L).

The test pattern is a stripe pattern of white or blue and black displayed vertically on the panel, and white and blue displayed horizontally on the panel, in the vicinity of the test pattern shown in Figure 1 (B).

This shows that, when the rotation axis 6 is shifted rearward from the display surface of the display panel 1a and the shift amount X mm is increased, the test pattern in front of the viewpoint becomes less missing in the center as shown in Figures 5(A)-(F), while the test pattern behind the viewpoint becomes more missing in the center as shown in Figures 5(G)-(L). The lower half of Figure 1(B) shows the drawable area when viewed from the viewpoint direction in the figure, but the reason that the missing area behind the viewpoint increases in the upper half as the shift amount is increased is because the field of view is blocked by the display panel 1a, increasing the blind spot behind the viewpoint.

To understand how the test pattern appears in front of the viewpoint and how the test pattern appears behind the viewpoint, experiments were carried out for X mm shown in Figure 1 (A) at 2 mm intervals from 0 to 10 mm, and the changes in the appearance of the test pattern were confirmed as shown in Figures 5 (A)-(L). Considering Figures 5 (A)-(L), it was found that in order to eliminate the loss of the test pattern in front of the viewpoint, it is necessary to position the rotation center 6 at a position 4 mm or more, preferably 8 mm or more, behind the display surface of the display panel 1a.

In this way, the inventors of the present application have found that by locating the rotation axis 6 of the panel support 1c at a position shifted a required small distance rearward from the display surface of the display panel 1a as shown in Figure 1(A), the blind spots are reduced as shown in Figure 1(B), and test patterns can be obtained in which the loss of the area in front of the viewpoint is significantly improved as shown in Figures 5(A)-(F). More specifically, when the distance from the rotation axis 6 to the display surface of the display panel 1a is changed to 4 mm or more, the loss of the area in front of the viewpoint of the displayed stereoscopic image is improved, and when it is 8 mm or more, the improvement is even better.

The appropriate distance from the rotation axis 6 to the display surface of the display panel 1a also depends on the display characteristics of the light-emitting element and the size of the display panel.

Figure 21 is a diagram showing the relationship between the intersection angle θ between the display panel 1a and the rotation center 6 when drawing at the center of the screen when viewed from a viewpoint, the shift amount X, and the horizontal length L of the panel when the display panel 1a shifted forward as shown in Figure 1 (A) rotates around the rotation center 6.

The intersection angle θ is expressed by the following formula.
θ=tan ⁻¹ (2×shift amount X/panel horizontal length (panel width) L)

From this formula, it can be seen that when θ is constant, the horizontal length L of the panel is proportional to the shift amount X of the display panel 1a. It can also be seen that the appropriate shift amount X mm of the display panel 1a depends on the emission angle characteristics of the light-emitting element shown in Figure 2 and the horizontal length L of the panel when the rotation axis 6 shown in Figure 1 (A) is aligned with the vertical direction of the display panel 1a. Therefore, the shift amount X mm is set to a value according to the panel size so that image loss can be effectively eliminated even when the display panel 1a is enlarged.

Figure 6 shows the results when a light-emitting element having the emission angle characteristics of Figure 2 is used, and the horizontal size of the panel is 100 mm (i.e., the diameter of the drawing area when viewed from the top of the device is 100 mm). At the position of the test pattern used in this experiment, an improvement was observed from 4 mm, and 8 mm or more is optimal. In other words, the effect is achieved when the separation distance is 4% or more of the horizontal length of the panel, and 8% or more is optimal. The larger the separation distance, the less the loss of the center of the test pattern in front of the viewpoint, but the undrawn area on the upper side (back side when viewed from the top of the device) shown in Figure 13 becomes larger. Therefore, it is desirable to set an appropriate separation distance. Also, as shown in Figure 1 (B), considering that the display position of the test pattern this time is approximately the center from the outermost periphery to the center of rotation of the display area, and considering the display of the outermost periphery, which is a more severe condition, the optimal separation distance is about twice the optimal value of 8% in this experiment. Therefore, it is desirable to keep the separation distance to 16% or less, which is twice the optimal value under the conditions this time.

Furthermore, the inventors of the present application have discovered that when a double-sided display is used, as shown in Figure 12, the distance from the rotation axis 6 to the display surface of the front display panel 1a is set to 10 mm, and the rotation axis 6 is aligned with the display surface of the rear display panel 1b, the 3D images of the front and rear display panels 1a and 1b overlap with a phase difference of 180 degrees, improving image loss, and furthermore, by shifting the pixels of the front display panel 1a and the pixels of the rear display panel 1b by a subpixel, the resolution of the image can be improved.

The inventors of the present application have also found that, when the rotation center 6 is located at a position X mm forward of the display surface of the display panel 1a (the display surface of the display panel 1a is shifted X mm behind the rotation center 6) as shown in Figure 1A(A), if X mm is changed to 0 mm, 2 mm, 4 mm, 6 mm, 8 mm, and 10 mm, the appearance of the test pattern in front of the viewpoint changes as shown in Figure 5(G)-(L), and the appearance of the test pattern behind the viewpoint changes as shown in Figure 5(A)-(F). Figure 1A(B) shows the drawable area as seen from the viewpoint, but the reason why there is a lot of missing area in front of the viewpoint is because the view is blocked by the display panel 1a, increasing the blind spot behind the viewpoint.

In both cases of Figure 1 and Figure 1A(A), where the display surface of the display panel 1a is shifted by X mm from the center of rotation 6, the loss of the test pattern on the rear or front side becomes large, but this can be compensated for by adopting a double-sided panel, which will be described later. However, when considering drawing on a single panel, it is desirable to set the shift amount of X mm so that the separation distance, which does not cause too much loss on the rear side of the viewpoint, is 16% or less of the horizontal length of the panel.

The inventors of the present application have discovered that, in order to make the important front of the viewpoint visible, it is desirable to have the center of rotation shifted backwards, but when emphasis is placed on the rear of the viewpoint, it is more desirable to shift the center of rotation forwards.

Next, the inventors of the present application explored whether it would be possible to increase the pixel resolution and improve the image quality of a single-sided display by a method other than increasing the integration density of light-emitting elements (LEDs). As a result, as shown in Figure 15, they discovered that if the rotation axis 6 of the panel support 1c is tilted at a small angle of, for example, 5-12 degrees with respect to the vertical line in the center of the panel support 1c, the vertical resolution appears to increase regardless of the elimination of the blind spot.

The inventors of the present application have also discovered that in a double-sided display, when display panels 1a and 1b are provided on the front and back of panel support 1c so that they are out of phase with each other by 180 degrees around rotation axis 6, and rotation axis 6 is aligned with the display surface of display panel 1b, two 3D images overlap well and appear to have a higher resolution than in a single-sided display. Furthermore, they have discovered that when front and back display panels 1a and 1b are shifted by a subpixel in the horizontal and/or vertical directions, the resolution appears to be significantly improved.

Furthermore, the inventors of the present application have found that when the front and back display panels 1a, 1b in a double-sided display are tilted at a small angle of, for example, 10 degrees and the front and back display panels 1a, 1b are rotated around the axis 6 with a phase difference of 180 degrees, the two 3D images overlap well and the vertical resolution appears to be higher than when tilted in a single-sided display. Furthermore, the inventors have found that when the front and back display panels 1a, 1b are tilted at a small angle in a double-sided display and are shifted by a subpixel, the resolution appears to be even higher.

As a result, we have come up with the idea of solving the above-mentioned conventional problems and realizing a stereoscopic imaging device that can create 3D images in a volumetric display that rotates a self-luminous two-dimensional display to create a 3D image with reduced blind spots in front of the viewpoint and improved defects in the front of the viewpoint.

Furthermore, they came up with the idea of creating a stereoscopic imaging device that can create 3D images that appear to have increased resolution in a volume display that rotates a self-luminous two-dimensional display to create a 3D image.

Therefore, in order to solve the above problems, the three-dimensional image device according to the first aspect of the present application, in order to achieve the above object, comprises: a self-luminous two-dimensional display means having a display panel on the front side of a panel support, in which light-emitting elements constituting each pixel are arranged vertically and horizontally, for emitting and displaying an image; a rotation means having at least one of an upper support shaft supporting approximately the middle of the upper end of the panel support and a lower support shaft supporting approximately the middle of the lower end, for rotating the display panel around a rotation axis passing through the axis; and a control means performing voxel drawing based on the position at which each of the light-emitting elements comes to a voxel corresponding to the rotation angle of the display panel, the rotation axis being located at a position spaced a required small dimension forward or backward from the display surface of the front-side display panel.

As a second aspect of the present application, in the first aspect, the rotation axis may be configured to be parallel to the column direction of the light-emitting element array arranged vertically and horizontally on the display panel.

As a third aspect of the present application, in the first aspect, the axis of rotation may be inclined at a required small angle to the right or left with respect to the column direction of the light-emitting element array arranged vertically and horizontally on the display panel.

As a fourth aspect of the present application, in any one of aspects 1 to 3, the rotation axis may be located at a position spaced apart from the display surface of the display panel by a distance corresponding to 4% or more of the lateral length of the panel. The upper limit of the shift amount is preferably a maximum of 40%, more preferably 30%, and even more preferably 20%.

As a fifth aspect of the present application, in any one of aspects 1 to 3, the rotation axis may be located at a distance from the display surface of the display panel that corresponds to 8-16% of the lateral length of the panel.

As a sixth aspect of the present application, in any one of aspects 1 to 3, the self-luminous two-dimensional display means may be configured such that a display panel is also provided on the rear side of the panel support, and the display panel on the front side and the display panel on the rear side are out of phase with each other by 180 degrees with respect to the rotation axis.

As a seventh aspect of the present application, in the sixth aspect, the self-luminous two-dimensional display means may be configured such that the arrangement of light-emitting elements on the front display panel and the rear display panel are shifted by a subpixel in the vertical and/or horizontal directions.

The stereoscopic imaging device of the eighth aspect of the present invention has, in addition to the configuration of the sixth aspect of the invention, a configuration in which the axis of rotation is arranged so that the distance from the axis of rotation to the display panel on the front side is different from the distance from the axis of rotation to the display panel on the back side.

As a ninth aspect of the present application, in the eighth aspect, the rotation axis may be arranged on the display surface of either the front display panel or the rear display panel.

As a tenth aspect of the present application, in the case of a single-sided display having the configuration in the first aspect, a light diffusion element may be provided on the display surface of the display panel.

As an eleventh aspect of the present application, in the case of a double-sided display having the configuration in the ninth aspect, a light diffusion element may be arranged only on the display panel that coincides with the axis of rotation.

As a twelfth aspect of the present application, in the first aspect, the control means may be configured to increase the frame rate in the outer rotating parts of the display panel and decrease the frame rate in the parts closer to the center in order to achieve a uniform voxel density over the entire surface of the display panel.

As a thirteenth aspect of the present application, in the first aspect, the control means may be configured to perform interlaced drawing when performing the voxel drawing.

As a fourteenth aspect of the present application, in the first aspect, the control means may be configured to detect the position of the viewpoint and/or face of a person located around the self-luminous two-dimensional display means and to extend the voxels backward from the viewpoint.

As a fifteenth aspect of the present application, in the fourteenth aspect, dithering may be applied using the expanded voxels.

As a sixteenth aspect of the present application, in the first aspect, the control means may be configured to detect the position of the viewpoint and/or face of a person located around the self-luminous two-dimensional display means, and to prevent see-through by controlling so as not to display any voxels other than those first visible from that point.

As a 17th aspect of the present application, in the 16th aspect, the detection target may be a face, and when the number of detections is 1, a one-person mode is set; when the number of detections is 2 or more but less than a certain value, a mode is set in which only the first visible voxel obtained by ORing all the detected voxels is drawn; and when there are multiple people equal to or more than a certain value, a everyone mode is set, in which no hidden surface processing dependent on the viewpoint angle is performed.

As an 18th aspect of the present application, in the first aspect, the self-luminous two-dimensional display means may be configured such that a plurality of light-emitting elements having different luminous colors each constitute one pixel, and the plurality of light-emitting elements constituting one pixel are arranged in a row along the axis of rotation.

As a 19th aspect of the present application, in the first aspect, the control means may be provided in the rotating part and configured to synchronously control the display of the image on the display panel, and a motor control means may be provided in the non-rotating part and synchronously control the motor rotation speed.

In addition, in order to solve the above-mentioned problems, the three-dimensional image device according to the twentieth aspect of the present application comprises a self-luminous two-dimensional display means having a display panel on the front side of a panel support, on which light-emitting elements constituting each pixel are arranged vertically and horizontally, for emitting and displaying an image, a rotation means having at least one of an upper support shaft supporting approximately the middle of the upper end of the panel support and a lower support shaft supporting approximately the middle of the lower end, for rotating the display panel around a rotation axis passing through the axis, and a control means performing voxel drawing based on the position at which each of the light-emitting elements comes to a voxel according to the rotation angle of the display panel, the rotation axis being in a position coinciding with the display surface of the display panel on the front side, and being inclined at a required small angle to the right or left with respect to the column direction of the light-emitting element array arranged vertically and horizontally on the display panel.

Furthermore, in order to solve the above problem, the three-dimensional image device according to the twenty-first aspect of the present application comprises a self-luminous two-dimensional display means having a display panel on the front side of a panel support, on which light-emitting elements constituting each pixel are arranged vertically and horizontally, for emitting and displaying an image, a rotation means having at least one of an upper support shaft supporting approximately the middle of the upper end of the panel support and a lower support shaft supporting approximately the middle of the lower end, for rotating the display panel around a rotation axis passing through the axis, and a control means performing voxel drawing based on the position at which each of the light-emitting elements comes to a voxel corresponding to the rotation angle of the display panel, and the self-luminous two-dimensional display means has a display panel also on the rear side of the panel support, the front-side display panel and the rear-side display panel are 180 degrees out of phase with each other with respect to the rotation axis, and the arrangement of light-emitting elements is shifted by a sub-pixel in the vertical and/or horizontal directions between the front-side display panel and the rear-side display panel.

Furthermore, in order to solve the above-mentioned problems, the three-dimensional image device according to the twenty-second aspect of the present application comprises a self-luminous two-dimensional display means having a display panel on the front side of a panel support, on which light-emitting elements constituting each pixel are arranged vertically and horizontally, for emitting and displaying an image, a rotation means having at least one of an upper support shaft supporting approximately the middle of the upper end of the panel support and a lower support shaft supporting approximately the middle of the lower end, for rotating the display panel around a rotation axis passing through the axis center, and a control means performing voxel drawing based on the position at which each of the light-emitting elements comes to a voxel corresponding to the rotation angle of the display panel, and the self-luminous two-dimensional display means has a configuration in which a plurality of light-emitting elements having different light-emitting colors each constitute one pixel, and the plurality of light-emitting elements constituting one pixel are arranged in a row along the rotation axis, and has the function of displaying a color image.

In addition, in order to solve the above problems, the stereoscopic imaging device according to the twenty-third aspect of the present application comprises a self-luminous two-dimensional display means having a display panel on the front side of a panel support, on which light-emitting elements constituting each pixel are arranged vertically and horizontally, for emitting and displaying an image; a rotation means having at least one of an upper support shaft supporting approximately the middle of the upper end of the panel support and a lower support shaft supporting approximately the middle of the lower end, for rotating the display panel around a rotation axis passing through the axis; and a control means for performing voxel drawing based on the position at which each of the light-emitting elements comes to a voxel corresponding to the rotation angle of the display panel, wherein the control means detects the position of the viewpoint and/or face of a person located around the self-luminous two-dimensional display means, and controls so as not to display any voxels other than those first visible from that position, thereby preventing see-through.

According to each aspect of the present invention, in a volume display that rotates a self-luminous two-dimensional display to create a 3D image, the axis of rotation is located a required small distance behind the display surface of the display panel, thereby providing a stereoscopic imaging device that can create a 3D image with reduced blind spots in front of the viewpoint and improved defects in front of the viewpoint.

According to each aspect of the present invention, in a volume display that rotates a self-luminous two-dimensional display to create a 3D image, the axis of rotation is tilted at a required small angle to the right or left with respect to the vertical direction of the light-emitting element array arranged vertically and horizontally on the display panel, thereby providing a stereoscopic imaging device that can create a 3D image that appears to have increased resolution.

(A) is a schematic plan view for explaining a characteristic configuration example of a self-luminous two-dimensional display according to an embodiment of the present invention. (B) is a plan view showing a blind spot area where a test pattern is not visible when a self-luminous two-dimensional display according to an embodiment of the present invention is rotated to display a test pattern, and shows a case where the test pattern is set in the middle of the lower half of the figure where there is no blind spot area. (C) is a plan view showing a blind spot area where a test pattern is not visible when a self-luminous two-dimensional display according to an embodiment of the present invention is rotated to display a test pattern, and shows a case where the test pattern is set in the middle of the upper half of the figure where there is a blind spot area. 1A is a schematic plan view for explaining another characteristic configuration example of a self-luminous two-dimensional display according to an embodiment of the present invention, and FIG. 1B is a plan view showing a blind spot area where a test pattern cannot be seen when the self-luminous two-dimensional display is rotated to display the test pattern. 1 is a schematic graph showing the emission light characteristics of a light-emitting element, for explaining the principle of the present invention. 13 is a diagram showing an actual image of a test pattern when the angle between a voxel of a display panel of a self-luminous two-dimensional display of a stereoscopic imaging device in a conventional example and the viewpoint is 0 degrees. FIG. 20. (A) is a diagram of a display panel viewed from directly above when the angle between the voxels of the display panel of the self-luminous two-dimensional display of the stereoscopic image device of the conventional example shown in FIG. 20 and the viewpoint is 0 degrees. (B) is a diagram of an actual image obtained when the angle between the voxels of the display panel of the self-luminous two-dimensional display of the stereoscopic image device of one embodiment of the present invention shown in FIG. 1 and the viewpoint is made larger than 0 degrees. (C) is a diagram of the display panel viewed from directly above when the angle between the voxels of the display panel of the self-luminous two-dimensional display of the stereoscopic image device of one embodiment of the present invention shown in FIG. 1 and the viewpoint is made larger than 0 degrees, and the display panel is rotated 180 degrees from (B). In the configuration shown in Fig. 1(A), the horizontal size (panel width) of the display panel is 100 mm, and the diameter of the drawing area when viewed from above the device is 100 mm. When the shift amount X mm of the display panel is changed to 0 mm, 2 mm, 4 mm, 6 mm, 8 mm, and 10 mm, Fig. 5(A)-(F) show the change in appearance of the test pattern present in the area in front of the viewpoint, and Fig. 5(G)-(L) show the change in appearance of the test pattern present in the area behind the viewpoint, at the test pattern display position shown in Fig. 1(B). FIG. 1 is a schematic diagram of a stereoscopic image display device common to first and second embodiments of the present invention. 1A and 1B are schematic diagrams of two types of frame-free stereoscopic image devices common to the first and second embodiments of the present invention. FIG. 1 is a block diagram showing an overall configuration of a stereoscopic imaging device according to an example common to the first and second embodiments of the present invention. FIG. 11 is a block diagram showing the overall configuration of a stereoscopic image device according to another example common to the first and second embodiments of the present invention. FIG. 2 is a schematic diagram for explaining a drawing algorithm according to an embodiment of the present invention. FIG. 2 is a schematic diagram for explaining a drawing algorithm according to an embodiment of the present invention. 1 is a schematic diagram illustrating a double-sided display according to an embodiment of the present invention; 13A, 13B, and 13C are diagrams for explaining drawing using the double-sided display shown in FIG. 12. 1 is a schematic diagram for explaining the arrangement of a double-sided display according to an embodiment of the present invention; FIG. 1A is an explanatory diagram showing a stereoscopic imaging device according to a first embodiment of the present invention, in which the display is rotated in a normal arrangement in which the light-emitting elements are aligned vertically and horizontally; FIG. 1B is an explanatory diagram showing a stereoscopic imaging device according to another embodiment of the present invention, in which the display is rotated at a required small angle relative to the rotation axis. 1A and 1B are explanatory diagrams showing a side view of a display and voxels seen from a viewpoint when the display is rotated in a normal arrangement in which light-emitting elements are aligned vertically and horizontally in a three-dimensional imaging device according to a first embodiment of the present invention, and voxels seen from a viewpoint when the display is rotated in a normal arrangement in which light-emitting elements are aligned vertically and horizontally; and 1C and 1D are explanatory diagrams showing a side view of a display and voxels seen from a viewpoint when the display is rotated in a normal arrangement in which light-emitting elements are aligned vertically and horizontally in a three-dimensional imaging device according to another embodiment. FIG. 11 is an explanatory diagram of a case where color light emitting elements of one pixel are vertically arranged according to another embodiment of the present invention. FIG. 11 is an explanatory diagram of a case where color light emitting elements for one pixel are arranged horizontally according to still another embodiment of the present invention. According to yet another embodiment of the present invention, (A) is an explanatory diagram showing that only the surface voxels corresponding to the first voxel from the viewpoint direction are enabled, (B) is an explanatory diagram showing that the voxels on the back side of the viewpoint are expanded in a stepped manner from the surface voxels, and (C) shows an embodiment in which the viewpoint angle is different from (B). FIG. 13 is a schematic plan view for explaining a self-luminous two-dimensional display means of a stereoscopic image device in a conventional example. This figure shows the relationship between the intersection angle between the display panel and the rotation center when drawing at the center of the screen when viewed from a viewpoint, the shift amount, and the horizontal length of the panel when the display panel shifted forward as shown in Figure 1 (A) rotates around the rotation center.

Below, the stereoscopic imaging device relating to an embodiment of the present invention is described with reference to the drawings.

[Configuration 1 common to the first to third embodiments]
FIG. 6 is an external view of a stereoscopic image device (also called a volume display) common to the first to third embodiments of the present invention, viewed from the front side of the viewpoint. As shown in FIG. 6, the stereoscopic image device 100 includes a self-luminous two-dimensional display means (hereinafter, the display panel 1a is treated as synonymous with the self-luminous two-dimensional display means) 1 having a display panel 1a in which LEDs are arranged vertically and horizontally on the front side of a panel support 1c, a slip ring 2, an encoder 3, a coupling 4, a motor 5 including a rotating shaft, and a rotating base box 7. In addition, as shown in FIG. 8, the rotating base box 7 includes a synchronous display control means (means for synchronously controlling the display panel and synchronously controlling the motor rotation speed) 10, a storage means 20, encoders 3a and 3b, a data conversion means 30, and a motor control means 40. As shown in FIGS. 7(A) and 7(B), the stereoscopic image device may be configured as an embodiment that does not require a frame for its external appearance. The self-luminous two-dimensional display means is not limited to LEDs as long as it is a two-dimensional display means that emits light, such as an organic EL element or a combination of a backlight source and a liquid crystal display.

As described above, the stereoscopic imaging devices according to the first and second embodiments both have in common a self-luminous two-dimensional display means 1 having a display panel 1a on the front side of a panel support 1c, a motor (rotation means) 5 including a rotation axis, and control means 10 for performing voxel drawing on the self-luminous two-dimensional display means 1.

The self-luminous two-dimensional display means 1 is configured such that a display panel 1a, in which multiple light-emitting elements that emit monochrome or colored light are arranged vertically and horizontally as pixels, is provided on the front side of a panel support 1c and displays an image through light emission (see Figures 1(A) and 1A(A)).

In the case of a color LED display panel, red [R], green [G], and blue (B) light-emitting elements (LEDs) 1ar, 1ag, and 1ab that make up one color pixel are arranged vertically and horizontally, and one or more of each pixel emit light to display a color. In the case of a monochrome LED display panel, light-emitting elements of appropriate emitting colors are arranged vertically and horizontally.

The motor (rotation means) 5, which includes a rotation shaft 6, is configured to rotate the panel support 1c around the vertical rotation shaft (rotation axis) 6 at the center of the width of the panel support 1c.

The control means 10 is configured to create an image sequence to be displayed on the display panel 1a from the voxel data and perform voxel drawing based on the position at which each pixel of the display panel 1a reaches the corresponding voxel depending on the rotation angle of the panel support 1c.

8 is a block diagram of the overall configuration of a common stereoscopic image device 100A according to the first and second embodiments of the present invention. As shown in the figure, the stereoscopic image device 100 according to one embodiment of the present invention is configured to include, for example, a display panel 1, a control means 10 that controls the synchronous display of images on the display panel 1, and a storage means 20 that the control means 10 can access as appropriate and store information, as elements that constitute the rotating unit 200. The display panel 1 is rotated around a rotation axis (rotation axis line) 6 that is rotated by a motor 5. The control means 10 sends a control signal to the motor 5 via a slip ring 2. A slip ring 2 connected to the control means 10 is disposed in the boundary area of the rotating unit 200. The encoder 3 is provided, for example, at a position separated from the rotating unit 200 and connected to the rotation axis 6 and the slip ring 2. In addition, for example, a data conversion means 30 provided in an external position (non-rotating unit) is connected to the control means 10 via the slip ring 2. The control means 10 may be realized, for example, by a CPU or MPU, and the storage means 20 may be realized, for example, by a ROM/RAM. A circuit board (not shown) serving as the control means 10 is arranged above or below the display panel 1, or on the back surface of the display panel 1, or in the case where the display panel 1 is arranged on both sides, it is composed of two display panels 1, and the circuit board (not shown) may be arranged between the display panels 1.

Next, according to the block diagram of the 3D imaging device 100, the rotating shaft 6 is rotated by the motor 5. The rotation information is acquired by the encoder 3 and sent to the control means 10 via the slip ring 2. The control means 10 adjusts the rotation speed of the motor 5 and the display timing on the display panel 1 based on the rotation information.

The data (multiple two-dimensional images) to be displayed on the display panel 1 is compressed and stored in the storage means 20. The control means 10 expands the data stored in the storage means 20 and draws the expanded data on the display panel 1. By setting the rotation speed of the motor 5 to an appropriate speed assumed at the time of data conversion and synchronously displaying an image on the display panel 1 from the control means 10 in accordance with the zero point position of the encoder 3, it is possible to display a still three-dimensional image.

Instead of the information stored in the memory means 20, display data (which may be compressed) converted in real time by an external data conversion means 30 may be displayed on the display panel 1 using the control means 10 via a network (not shown) via the slip ring 2.

If the display data is compressed, it is expanded by the control means 10. Alternatively, the data may be sent directly from the data conversion means 30 to the control means 10 via a wireless communication means (not shown) such as contactless Wi-Fi, without passing through the slip ring 2. When the data conversion means 30 performs real-time conversion, the user's actions can be reflected in real-time.

[Configuration unique to the first and second embodiments]
The characteristic configuration of the stereoscopic imaging device according to the aspect of the present invention is to eliminate the loss of a narrow central portion of a 3D image when viewed from the front of the viewpoint, and the means for solving this is to displace the display panel 1a from the rotation axis 6, to tilt it with respect to the rotation axis 6, or to provide both a displacement and a tilt. Specifically, the present invention can be divided into the following first and second embodiments.

[Characteristic configuration of the stereoscopic image device according to the first embodiment]
As shown in FIG. 1(A), the three-dimensional image device of the first embodiment is configured such that the axis of rotation 6, which is the vertical axis of the panel support 1c, is in the vertical direction that coincides with one vertical row or between two vertical rows in the array of light-emitting elements arranged vertically and horizontally that constitutes the display panel 1a when viewed from the front, and is located a required small distance behind the display surface of the display panel 1a.

The blind spot in front of the viewpoint can be reduced by this configuration, which will be explained again with reference to Figures 4 and 5. Figure 4(B) is a view of the rotating display panel 1a as viewed from directly above when the display panel 1a in the configuration of Figure 1 is an LED panel and is shifted X mm in the direction in front of the viewpoint (forward) from the rotation axis 6, and Figure 5 is a diagram showing how the test pattern in the area in front of the viewpoint appears when the display panel 1a in the configuration of Figure 1, which has a length of 100 mm in the horizontal direction of the panel, is shifted from the rotation axis 6 to 0-10 mm in shift dimensions X mm in the direction in front of the viewpoint in increments of 2 mm, as already described. According to this, the appearance of the test pattern in front of the viewpoint changes as shown in Figures 5(A)-(F), and the appearance of the test pattern behind the viewpoint changes as shown in Figures 5(G)-(L).

When the display panel 1a shifts forward from the rotation axis 6 as shown in Figure 1(A), if the shift dimension X mm is less than 4 mm, the angle between the viewpoint and the voxels of the display panel 1a is approximately 0 degrees as shown in Figure 4(A), and the voxels in front of the viewpoint are in a blind spot, resulting in an image with a missing center as shown in Figures 5(A) and (B). However, if the shift dimension X mm is 4 mm or more, the angle between the viewpoint and the voxels of the display panel 1a becomes greater than 0 degrees as shown in Figure 4(B), and the voxels in front of the viewpoint are no longer in a blind spot. As a result, the test pattern viewed from in front of the viewpoint has an image with improved central defects as shown in Figures 5(C)-(F). The resulting image does not have a missing center.

Similarly, when the display panel 1a shifts rearward from the rotation axis 6 as shown in Figure 1A (A), and the shift dimension X mm is 4 mm or more, the voxels in front of the viewpoint are no longer in a blind spot, and an image is obtained in which the test pattern in the area behind the viewpoint has the central defect improved, as shown in Figures 5 (C)-(F).

Furthermore, as a secondary effect of shifting the display panel 1a from the rotation axis toward the front of the viewpoint, the voxels in front of the viewpoint are written twice per rotation, improving the voxel density in front of the viewpoint, where the most resolution is required visually. Figure 4(C) is a diagram of the point when it is rotated 180 degrees further than Figure 4(B). Here, too, voxels in the same positions as those in Figure 4(B) are drawn. In other words, when the display panel 1a is shifted forward with respect to the rotation center, the voxels in front of the viewpoint are drawn twice per rotation. The darker parts at the bottom of Figure 13 are the parts that are drawn twice per rotation. (Instead, there is a blind spot behind the viewpoint that is not drawn). Since the visually important part in front of the viewpoint can be drawn twice per rotation, the refresh rate of the screen can be doubled. Therefore, it is possible to suppress flickering in the important part in front of the viewpoint and realize smooth moving videos without increasing the rotation speed of the panel, which is mechanically difficult.

[Characteristic configuration of the stereoscopic image device according to the second embodiment]
The stereoscopic image device according to the second embodiment has the characteristic configuration of the first embodiment, and in addition thereto, a rotation axis 6 is inclined at a required small angle with respect to the display panel 1a. That is, although not shown, this characteristic configuration is such that the rotation axis, which is the vertical axis of the panel support, is in the vertical direction inclined at a required small angle to the right or left with respect to a vertical row of light-emitting elements in the array of light-emitting elements arranged vertically and horizontally on the display panel, approximately in the middle of the row, and is located at a position spaced a required small distance behind the display surface of the display panel.

In more detail, as shown in Figures 15(B), 16(C) and [D], the rotation axis 6, which is the vertical axis of the panel support 1c, coincides with a vertical line, and when viewed from the front, the light-emitting element array is arranged vertically and horizontally to constitute the display panel 1a. The light-emitting elements are tilted at a required small angle, for example 5-12 degrees, preferably 8-10 degrees, from the vertical row of light-emitting elements approximately halfway between the horizontal rows, and the rotation axis 6 coincides with the display surface of the display panel 1a. The optimal angle of tilt varies depending on the density of the light-emitting elements in the light-emitting element array.

As shown in Figures 4 and 15(B), if the rotation axis 6 is held vertically and the display panel 1a is tilted to the left (or right), as shown in Figures 16(C) and [D], the vertical voxels will be shifted in the depth direction when viewed from the front, and therefore the resolution can be increased in the vertical direction in a pseudo manner for an object with voxels in the depth direction. Figures 15(A), 16(A), and (B) correspond to the characteristic configuration of the stereoscopic image device of the first embodiment, and show the case where the display is rotated in a normal arrangement in which the light-emitting elements are aligned vertically and horizontally, in which case the vertical voxels do not shift in the depth direction.

[Third embodiment: double-sided display]
The third embodiment of the present invention is common to both the first and second embodiments described above, and has an additional feature in addition to the characteristic features of the first and second embodiments, in which a display panel 1a is provided on the front side of a panel support 1c, and a display panel 1b is provided on the rear side of the panel support 1c, as shown in Fig. 12. In the following description of the double-sided display, the display panel provided on the front side of the panel support 1c is also referred to as the front panel, and the display panel 1b provided on the rear side is also referred to as the rear panel.

In the case of a double-sided display, the 3D image obtained by rotating the double-sided display is a composite of the 3D image from the front panel and the 3D image from the back panel. If the rotation axis 6 is located at the center of the thickness of the panel support 1c and the distance from the rotation axis 6 to the front panel 1a and the distance from the rotation axis 6 to the back panel 1b are the same (same shift amount), the two 3D images obtained from the front panel 1a and the back panel 1b will have the undrawn part of 13 upside down, and the other parts will be the same. This is not sufficient to eliminate the blind spot where the central part of the width is missing when viewed from the front. Therefore, the distance from the front panel 1a to the rotation axis 6 and the distance from the back panel 1b to the rotation axis 6 are made different. By making the two 3D images obtained from the front panel 1a and the back panel 1b different, the blind spot occurring in the 3D image of one display panel can be eliminated by superimposing a 3D image that does not cause a blind spot on the other display panel.

The embodiment shown in Figure 12 shows a double-sided display in which a back panel 1b is added to the single-sided display (front panel 1a) of the first embodiment shown in Figure 1, with the rotation axis 6 being aligned with a vertical line in the center of the width of the front surface of the back panel 1b, and the front panel 1a being shifted forward from the rotation axis 6 by a distance corresponding to 4% or more of the horizontal length of the panel. The preferred upper limit of the shift amount is a maximum of 40%, preferably 30%, and even more preferably 20%. A more practically preferred shift amount is a distance corresponding to 8-16% of the horizontal length of the panel.

If the shift amount dimension of the front panel 1a is 10 mm, in a double-sided display, the 0.5 mm protruding portions on both sides of the 9 mm thick panel support 1c become the light emission centers of the front panel 1a and the back panel 1b (see FIG. 17), and the distance from the light emission center of the front panel 1a to the light emission center of the back panel 1b becomes 10 mm. If the rotation center is set to coincide with the light emission center of the back panel 1b, the distance from the rotation center to the light emission center of the front panel 1a becomes 10 mm. In this example, "the rotation axis 6 is arranged to coincide with the front surface of the back panel 1b" takes into account that the rotation axis 6 is aligned with the light emission center in the protruding direction of the light-emitting element. In a single-sided display, the 0.5 mm protruding portion on the front side of the 9.5 mm thick panel support 1c becomes the light emission center of the front panel 1a, and the distance from the light emission center of the front panel 1a to the back surface of the panel support 1c becomes 10 mm.

In FIG. 12, the center of rotation (axis of rotation) 6 coincides with the vertical direction that coincides with one vertical row or the vertical direction that coincides with the space between two vertical rows in the light-emitting element array arranged vertically and horizontally on the back panel 1b. With this configuration, the front panel 1a shifts, for example, 10 mm forward with respect to the axis of rotation 6, and the center of rotation (axis of rotation) 6 exists on the surface of the back panel 1b. Due to this arrangement, the light-emitting element array of the back panel 1b results in a 3D image with a missing part in the center of the width when viewed from the front, but the shifted light-emitting element array of the front panel 1a overlays the 3D image over the entire surface including the missing part, so that the visually important front part is not missing and a 3D image with the missing part largely eliminated is obtained.

Figure 13(C) is a plan view for explaining that the blind spot can be eliminated by overlapping the radiation area of the emitted light when the front panel rotates and the radiation area of the emitted light when the back panel rotates in the double-sided display shown in Figure 12. If, as shown in Figure 13(B), a single-sided display is used and the center of rotation coincides with the display surface of the display panel, a blind spot occurs in the center vertical direction. Also, in the single-sided display shown in Figure 1, as shown in Figure 13(A), if the display surface of the display panel is shifted backward from the center of rotation, the rear center part of the display panel (the part shown in white in Figure 13) is not drawn and becomes a blind spot (the same applies when it is shifted forward). And, according to the double-sided display shown in Figure 12, as shown in Figure 13(C), there is no blind spot other than the rear center part of the back panel (the part shown in white in Figure 13), and almost the entire area can be drawn, including the important front of the viewpoint (lower part of the figure). (Even in the double-sided display, a blind spot remains in this part)

In a double-sided display, it is preferable that the vertical and horizontal arrangement of light-emitting elements on the front panel 1a and the vertical and horizontal arrangement of light-emitting elements on the back panel 1b are shifted vertically and/or horizontally by half a pitch (subpixel) of the arrangement of light-emitting elements.

As shown in Figure 14, the vertical resolution can be increased by arranging the light-emitting elements of the shift display panel (front panel) and the light-emitting elements of the rear panel with a subpixel vertical offset. Also, the horizontal resolution can be increased by arranging the light-emitting elements of the shift display panel and the light-emitting elements of the rear panel with a subpixel horizontal offset. Furthermore, the horizontal and vertical resolutions can be increased by shifting the light-emitting elements of the shift display panel and the light-emitting elements of the rear panel diagonally by a subpixel so that the vertical and horizontal subpixel offsets are combined.

As for the use of multiple display panels other than the above-mentioned double-sided display that uses two display panels, a display with three display panels arranged in a Y shape or a display with four display panels arranged in a cross shape can be considered. However, in such cases, a display panel located on the front side may be hidden by the other display panels behind it, creating blind spots, so the above-mentioned double-sided display that does not create blind spots is most suitable.

The single-sided display (front panel) of the second embodiment shown in Figure 15 (B) is configured to be tilted at a required small angle, for example 7-12 degrees, preferably 8-10 degrees, to one side with respect to the rotation axis 6, which is a vertical line, when viewed from the front. The double-sided display shown in Figure 12 also includes a double-sided display in which a back panel is added to this single-sided display.

In this configuration, the inclination of the front panel 1a and the inclination of the back panel 1b must be axially symmetrical (a state in which there is a rotational phase of 180 degrees) with respect to the rotation axis 6, and it is sufficient that either one of the display panels, the front panel 1a or the back panel 1b, is shifted from the rotation axis 6 by a distance preferably corresponding to 8-16% of the panel's horizontal length, and the other is aligned with the rotation axis 6. The configuration is essentially the same regardless of which front panel the rotation axis 6 is aligned with.

With this configuration, either the front panel 1a or the back panel 1b is shifted with respect to the rotation axis 6, so that as shown in FIG. 13(C), the 3D image produced by the rotation of the front panel 1a and the 3D image produced by the rotation of the back panel 1b overlap, and the loss of the central part of the width when viewed from the front is greatly reduced. In addition, since both the front panel 1a and the back panel 1b are arranged axially symmetrically with respect to the rotation axis 6, the 3D image produced by the rotation of the front panel 1a and the 3D image produced by the rotation of the back panel 1b fill in the vertical pixel gaps, making the image highly detailed, and in this state the 3D images on the front and back overlap in a matched state. As a result, a 3D image with extremely little loss and increased vertical image resolution is obtained.

Furthermore, even in a double-sided display that is tilted with respect to the axis of rotation 6, it is preferable that the vertical and horizontal arrangement of the light-emitting elements on the front panel and the vertical and horizontal arrangement of the light-emitting elements on the back panel are offset by a subpixel in the vertical and/or horizontal directions. This allows for a 3D image with improved vertical and/or horizontal image resolution.

Unlike the above configuration, if the front panel and back panel are configured to be inclined at the same small angle of 7-12 degrees to the same side relative to the rotation axis 6, which is a vertical line, when viewed from the front, the 3D image obtained by rotating the front panel about the rotation axis 6 and the 3D image obtained by rotating the back panel about the rotation axis 6 will rotate around the rotation axis 6 at opposite inclination angles, and the pixels of the front panel and back panel will be more misaligned toward the top and bottom of the front panel and back panel, resulting in the two 3D images overlapping in a blurred state as they move apart vertically, which is undesirable.

In a double-sided display having display panels 1a and 1b, the narrow portion extending from the top to the bottom of the display width center is drawn on the display panel shifted from the rotation axis 6. When a back display is added to the single-sided display shown in FIG. 1(A) to make a double-sided display, the blind spot of the back panel whose front surface coincides with the rotation axis 6 (the narrow portion extending from the top to the bottom of the display width center) is included, and the blind spot can be significantly reduced while being compensated for as a whole by drawing on the back panel placed at the center of the rotation axis of the front panel shifted forward from the rotation axis 6. In addition, the screen refresh rate can be doubled in the area drawn on both the front and back display panels. Therefore, it is possible to suppress screen flicker and realize smooth moving videos without increasing the rotation speed of the display panel, which is mechanically difficult.

[Configuration 2 common to the first and second embodiments]

[Circuit-related embodiment 2]
9 is a block diagram of a schematic overall configuration of another example of a stereoscopic image display device 100A common to the first and second embodiments of the present invention. The configuration shown in the figure is suitable for the case where a slip ring with a durable life is not used. The difference in configuration from the first embodiment is that an encoder for display synchronization control (encoder 3b in the figure) is used instead of the slip ring 2, and motor control means 40 is used to control the number of rotations of the motor.

As shown in the figure, rotation information is obtained using two encoders, an encoder 3a for motor rotation speed control and an encoder 3b for display synchronization control, and synchronous display control on the display panel 1 is performed using the control means 10, while motor rotation speed control is performed using the motor control means 40. Furthermore, when drawing information is sent in real time from the data conversion means 30, a configuration without a slip ring can be realized by using non-contact communication. In this case as well, the control means 10 and storage means 20 may be installed on the top or bottom of the display panel 1, or on the back side of the display panel 1, or between the two display panels 1 when the display panels 1 are arranged on both sides.

The power supply for the control means 10 of the rotating part and the display panel 1 may be provided via a slip ring 2 (see FIG. 8), or alternatively, power may be supplied wirelessly between the fixed part and the rotating part. In addition, when data is supplied to the control means 10 by non-contact communication, particularly wirelessly, as shown in FIG. 7(B), the antenna in the rotating part is installed in a part that does not move due to rotation and is symmetrical with the rotation axis (for example, a rod-shaped antenna is installed on or within the rotation axis), which allows a high data communication bandwidth to be achieved and enables high-quality display. However, if the position changes at any time due to rotation, the radio wave state is constantly changed, the wireless communication speed drops, and the amount of data that can be displayed decreases, resulting in a decrease in the frame rate of the display panel 1, making it difficult to achieve high image quality.

As shown in Fig. 7(B), the rotating part of the display panel 1 may be covered with an exterior such as a transparent cylinder made of acrylic or the like for safety reasons. In this case, the exterior may be coated with an anti-reflective coating to reduce reflection of external light. In addition, the inside of the panel may be reduced in pressure to create a vacuum, or filled with a gas lighter than air such as helium, to reduce noise and vibrations caused by air currents during rotation.

[Embodiment in which a light diffusion element is provided]
In the single-sided display stereoscopic image device according to the first and second embodiments, it is preferable that a light diffusion element is provided on the display surface of the front display panel. By attaching a light diffusion element that widens the emission light characteristics of the light emitting element to the front of the display panel, blind spots can be further reduced. As the light diffusion element, a transparent body with a rough surface or a plate having small microlenses at the pixel unit of the display panel is suitable.

In addition, in the double-sided display stereoscopic image device according to the third embodiment, when light diffusion elements are provided on both sides, the external light reflection by the diffusion elements becomes large, so that the display image is more susceptible to the influence of external light than a single-sided display, and the contrast of the display image may decrease. For this reason, since a wider emission angle characteristic is required, it is not desirable to provide light diffusion elements on both the front panel and the back panel in a double-sided display, and it is desirable to provide a light diffusion element only on the display panel whose front surface coincides with the rotation axis 6 among the two display panels on the front and back sides. This is because a wide emission angle characteristic is required for the display panel whose front surface coincides with the rotation axis 6 to reduce blind spots, and therefore attaching a light diffusion element to the front of the back panel is highly effective in reducing blind spots.

The light diffusion element may also have the function of a spatial LPF (Low-Pass Filter) that has an anti-aliasing function (a function that smooths pixel dots to make them less noticeable) that corresponds to the spatial density of the light-emitting elements of the display panel. By blurring the image using a spatial LPF, which is a plate-shaped optical component, aliasing noise can be reduced and the display quality of three-dimensional images can be improved. Generally, a scatterer with a rough surface blurs the image depending on its thickness, and therefore has the effect of a spatial LPF. Therefore, the light diffusion element may be given the function of a spatial LPF.

Furthermore, by placing a wavelength-limiting filter (bandpass filter) over the entire surface of the display panel that absorbs light other than the emission wavelength from the display panel's light-emitting elements, the contrast of the displayed three-dimensional image can be increased because it absorbs light other than the light from the display panel.

[Configuration and arrangement of color light-emitting elements constituting one pixel]
The self-luminous two-dimensional display means according to the aspects of the present invention includes not only a case where single-color light-emitting elements are arranged vertically and horizontally, but also an embodiment in which color light-emitting elements are arranged vertically and horizontally as shown in Figures 17 and 18, and includes the following embodiments regarding the configuration and arrangement of the color light-emitting elements that constitute one pixel.

[Arrangement of Light-Emitting Elements]
As shown in Fig. 17, when red [R], green [G], and blue (B) light-emitting elements are arranged at a position offset toward the back of the page, for example, when viewed from the front of the page, the green and blue pixels at the back are hidden by the red pixels at the front, and the colors cannot be seen. This causes the color to change between the right and left sides of the center when viewed from the periphery of the device. In this case, the arrangement of the RGB elements causes a phenomenon in which the colors are different on the left and right when viewed from the front. This phenomenon occurs because if red [R], green [G], and blue (B) light-emitting elements are arranged in a plane perpendicular to the rotation axis, the light-emitting elements at the front are in a blind spot, and the light-emitting elements at the back cannot be seen.

As a countermeasure to this, it is desirable to arrange the red [R], green [G], and blue (B) light-emitting elements that make up one pixel in a line along the rotation axis, as shown in Figure 17. This makes it possible to project a three-dimensional image whose color does not change regardless of the position around the device from which it is viewed. In this embodiment, if the light-emitting elements of each color are arranged offset up or down, there will be no problem in which, for example, a red pixel is hidden by a green pixel and the color cannot be seen when viewed from the front of the page. Note that it is not necessary for the light-emitting elements of each color to be arranged in a straight line along the rotation axis, as long as the positions of the light-emitting elements of each color are offset in the direction of the rotation axis.

[Other aspects common to all embodiments]
The aspects described below are, in principle, common to the first to third embodiments, and are additional configurations for each of the first to third embodiments.

[Rendering Algorithm]
As shown in FIG. 10, corresponding voxel data is generated from data 230 that indicates a three-dimensional shape. Reference numeral 240 in FIG. 10 indicates all the generated voxel data. An image sequence 324 is generated from all the voxel data 240 to be displayed on the display panel 1a or the display panel 1b every time the angle changes by one frame. FIG. 11 shows an example of drawing a cube. As shown in FIG. 11(A), (B), and (C), a cross section (reference numerals 320, 325, and 350) obtained by cutting a cube on a corresponding plane every time the rotation angle of the display panel 1a changes is considered, and an image to be displayed on the display panel 1 is generated by using a coordinate conversion process from voxel data 250 that indicates a cube shape so as to form a cross section in each state according to the rotation angle of the display panel 1. Reference numerals 300, 305, and 310 indicate the position of the display panel in each state.

As described above, as shown in Fig. 10, an image sequence 324 to be displayed on display panel 1a or 1b is created from voxel data 240 based on the position where each pixel of display panel 1a or 1b reaches the corresponding voxel due to rotation. However, a clear difference from the prior art is that in the present application, the corresponding position is calculated taking into consideration the misalignment of display panel 1a or 1b with rotation axis 6, and image sequence 324 is created by coordinate transformation. For example, coordinate transformation processing is performed so that 5,000 frames per second are drawn on display panel 1a or 1b.

When transmitting the image sequence 324 to the display panel 1a or 1b, the number of pseudo voxels can be increased by performing interlace drawing, which increases the number of drawing operations without increasing the transmission rate or bandwidth. In this case, it is preferable to draw all voxels in multiple rotations while shifting the position at the subvoxel level, rather than drawing all voxels in one rotation, thereby increasing the number of pseudo voxels that can be drawn without increasing the frame rate (frames per second; fps; a unit that indicates the number of images displayed per second) of the display panel.

[Embodiments relating to voxel density for increasing the rendering update frequency of the outer periphery of rotation]
When images are displayed on the entire surface of the display panel 1a or 1b at the same frame rate, the difference in rotation speed between the outer side and the center side of the display panel 1a or 1b results in a lower voxel density on the outer side and a higher voxel density on the inner side. In order to achieve a uniform voxel density rather than displaying images on the entire surface of the display panel 1a or 1b at the same frame rate, the control means 10 increases the frame rate of the outer rotating part of the display panel 1a or 1b and decreases the frame rate of the part closer to the center. Similarly, the display brightness is darker on the outer side due to the lower voxel density, so it is preferable to increase the brightness of the outer side of the display panel compared to the inner side.

[Hidden Surface Processing]
The control means 10 may, if necessary, leave only the voxels on the surface when the device is viewed from all sides and delete the rest. However, this is not necessary if it is desired to capture the inside of an object.

[Hidden surface processing to eliminate transparency]
The control means 10 invalidates voxels other than those initially visible from the viewpoint in order to eliminate transparency as necessary, but this is not done when it is desired to project an image that can be seen from all around.

[calibration]
If the positions of the display panels 1a and 1b are slightly different from the expected positions, the control means 10 performs position calibration (adjustment for accurate and stable reproduction) and performs coordinate conversion based on the result of the calibration, thereby enabling a better stereoscopic image to be displayed.

[Dithering]
When the display panel 1a or 1b can only be turned on/off, the control means 10 expresses gradation by dithering (a technique for expressing intermediate colors by mixing and arranging pixels of different colors randomly when reducing the number of colors in an image or creating or editing an image with a small number of colors). Dithering may be performed in the voxel state, or dithering may be performed on an image sequence after coordinate transformation. If possible, dithering using a three-dimensional dithering pattern (after coordinate transformation, two dimensions plus three dimensions on the time axis) rather than two-dimensional can provide better image quality.

[Embodiment equipped with a camera etc. for detecting people in the vicinity]
In the above first and second embodiments, by arranging a face detection camera, a sensor for detecting a face or an eye, or other weight sensor capable of making a judgment, the following changes can be made to the display of the 3D image. By changing the following embodiment of the see-through countermeasure according to this mode, it is possible to display a 3D image optimal for the situation. In addition, by providing a mechanism for recording or transferring images from the face detection camera to the outside at any time, it is possible to calculate the customer attraction effect of the device based on the number and expressions of people around the device. In addition to the face detection camera, people around the device may be detected using a distance sensor or a weight sensor arranged around the device, although the accuracy is reduced because the vertical angle cannot be determined.
[1] If the number of detected people is one, the 3D image display is set to one-person mode.
[2] If the number of detected people is two, the 3D image display is set to two-person mode.
[2] When there are three or more people, use the everyone mode (no hidden surface processing dependent on viewpoint angle).

[Embodiments of measures against see-through of displayed image]
In the present application, the following embodiment is preferable as a countermeasure against image see-through that occurs in a spatial scanning type volume display.
[1] In principle, if there is only one person viewing the image and the direction of that person's viewpoint is known, all voxels other than the first voxel from that viewpoint that is to be made transparent on purpose are hidden (invalidated or hidden from view). This makes it possible to eliminate image see-through. (Single-person mode)
[2] When multiple people are watching at the same time, hidden surfaces are removed by taking the OR of the viewpoints of the two people (two-person mode).
[3] When detecting a face and performing hidden surface processing, it is necessary to perform conversion processing in real time, which increases the amount of processing, but even if this is not performed, it is better to divide the 360-degree circumference of the viewing direction into 10 and perform pre-rendering (preparing the display data of the display panel by performing the above-mentioned drawing algorithm in advance) for each 36 degrees, and switch the playback data according to the direction of face detection. In this case, although it depends on the number of pre-rendering data corresponding to the angles prepared in advance, the switching of angles is discrete, so errors will occur, so it is better to perform pre-rendering with a lenient angle range for hidden surface processing. By doing so, it is possible to allow the boundary to be transparent to a certain extent, and to prevent a situation in which voxels are missing when viewed from all necessary angles when multiple people are watching.
[4] Even if face detection is not performed using the 360-degree camera, a switch may be provided that can be operated by a person to switch between one-person mode, two-person mode, and all-person mode.

[Embodiment for expanding voxels from the viewpoint to the back side]
FIG. 19(A) shows an embodiment in which only the surface voxels corresponding to the first voxel from the viewpoint direction are enabled. FIG. 19(B) shows an embodiment in which voxels on the back side of the viewpoint are expanded in a stepped manner from the surface voxels (filled with the same brightness and color). FIG. 19(C) shows an embodiment in which the angle of the viewpoint is different from that of (B). In FIG. 19(B) and FIG. 19(C), when dithering is used, gradation can be expressed in the depth direction, improving the image quality when viewed from the viewpoint. In addition, the number of effective voxels increases, which has the effect of making the image brighter.

[Embodiment with dimming and illuminance sensor]
When using the present method in a dark environment, flickering caused by the rotation of the display panel may be noticeable. In a dark environment, it is desirable to reduce the illuminance of the display panel accordingly. For this reason, it is advisable to install an illuminance sensor that detects the illuminance of the environment on the main body, and perform dimming to increase contrast by changing the illuminance of the display panel (the amount of light emitted by the LED) according to the output value of the illuminance sensor.

A simple method for changing the illuminance of the display panel is to shorten the lighting time of the LEDs on the display panel for drawing each frame or each line. When adjusting the amount of dimming for each line, the amount of dimming is adjusted according to the maximum luminance of that line, and by generating the display image with this adjustment in mind, the ability to express gradations increases even with the limited amount of information per pixel, making it possible to display three-dimensional images with a high dynamic range.

[Equipped with a function to cool using wind]
The motor that is heating up may be cooled by wind generated by a rotating LED display panel, or by a propeller attached to the rotating shaft and the wind generated by the propeller.

[The structure is such that sound-absorbing material is packed underneath]
The slip ring and motor under the LED display panel generate noise due to vibration, so by placing sound-absorbing material on the lower part, which does not need to be seen from the outside, the noise level can be reduced.

[Features include a motor temperature sensor to prevent motor damage]
A temperature sensor may be provided on the motor so that if the motor temperature exceeds a certain level, it detects that some abnormality has occurred and stops the motor to prevent damage to the motor.

[Function to prevent runaway motor rotation]
Generally, motor drive control is performed using the PWM method, and the motor drive force is adjusted by the duty ratio that is on. In the event that the motor speed control goes out of control for some reason and the motor drive force becomes abnormally large, the motor drive voltage is set to a voltage that has a slight margin above the LED display panel rotation speed regulation to prevent the LED display panel rotation speed from increasing abnormally and causing various parts to break down. As a result, even if the motor is controlled at 100% drive, the rotation speed will only be slightly higher than the LED display panel rotation speed regulation, so damage can be avoided.

[Function to turn off the display panel if the RPM deviates from the specified value]
If the number of rotations of the motor deviates from a specified number, a normal stereoscopic image cannot be displayed, so the LED display panel may be turned off to prevent the display contents from being displayed. In addition, if the number of rotations of the motor deviates from a specified number, a liquid crystal shutter or a movable blind member installed on the protective display panel may be used to block the LED display panel itself from being seen by the user, which is more effective because the rotation of the LED display panel cannot be seen when the LED display panel is turned off.

[A structure having a transparent protective display panel]
In the pipe structure supporting the LED display panel 1 shown in FIG. 6, the rectangular frame part on the back side blocks the view around the LED display panel, so the rectangular frame part may be made of a transparent pipe, and the LED display panel 1 may be surrounded by a transparent circular plate (not shown) and closed on the top by a transparent disk (not shown) to form a closed space that allows the surroundings of the LED display panel 1 to be seen through from the outside. Furthermore, the transparent disk on the top may have holes or slits through which air can pass in order to prevent the movement of wind caused by the rotation of the LED display panel and to prevent noise and instability in the rotation. Even if broken parts are scattered around by centrifugal force, they will not be scattered because there is no centrifugal force above and below. Therefore, there is no problem even if there are holes or slits on the top. The lower part including the rotating base box 7 may be closed with an opaque plate material.

[AR coating on protective display panel]
A transparent protective display panel such as acrylic may be arranged around the LED display panel rotor to prevent the LED display panel and other components from being broken and scattered around by centrifugal force. In this case, the transparent protective display panel may have an AR (Anti-reflective) coating on its surface so as not to reflect external light or light from the LED display panel.

[Safety with vibration sensors, adjusting weight position]
The LED display panel rotating body will vibrate if the weight balance is lost. Therefore, a vibration sensor attached to the device structure or the rotating shaft may be used to measure the magnitude of vibration at any time, and if an abnormal vibration is detected, an emergency stop may be performed to prevent damage to the device, or the user may be notified of the abnormality. In addition, it is desirable to have a mechanism for adjusting the position of the weight previously installed on the rotating body, or the weight of the weight itself, so that the detected vibration is reduced.

[Provide an emergency stop button]
If a physical part of a rotating body, such as an LED display panel, is damaged, there is a possibility that it may be scattered toward the user due to centrifugal force, so a configuration may be provided in which an emergency stop button is provided to cut off the power supply to the motor and the LED display panel itself in the event of an emergency.

[The configuration must enable remote diagnosis via network]
The control means may be configured to be connected to the outside via a network in order to obtain monitor information from various devices, such as the motor rotation speed, vibration sensor information, external environmental illuminance, LED display panel display content, and motor temperature, from the outside or a remote location, or to issue instructions such as to start rotation or display from the outside or a remote location.

The stereoscopic imaging device according to each embodiment of the present invention generally provides a sense of unity between reality and virtuality, and no misalignment or inconsistency in spatial coordinates occurs between the real space and the image, no matter where you look. In other words, a sense of unity is created between reality and the image, and the motion sickness that is unique to 3D is not caused.

As described above, the stereoscopic imaging device according to the aspect of the present invention can realize an imaging system that can project 3D content in 3D form into physical space (spot), making it possible to materialize 3D content that exists in virtual space in the fields of game characters, avatars, digital archives, art/NFT, digital humans, and virtual communication in a more tangible way in the real world; in other words, it makes it possible to elevate 3D content in virtual space into a more tangible presence.

Therefore, the stereoscopic imaging device according to the present invention can provide listeners and target audiences with an amazing experience as if 3D content were appearing right there in the field, for example, in the video, gaming and advertising industries, and is expected to increase the promotional effect with innovative images.

Furthermore, the stereoscopic imaging device according to the embodiment of the present invention can be expected to contribute to more effectively producing limited promotional opportunities, for example in marketing activities, by attracting customers through eye-catching effects and creating a memorable atmosphere.

Furthermore, the stereoscopic imaging device according to the embodiment of the present invention can be said to be an XR technology optimized for real-life promotion, allowing for an immediate experience, for example, at an event. It is expected that customers visiting an event venue where many people are coming and going will be able to experience the experience instantly, without the need to wear special glasses, install an application, or read a QR code (registered trademark).

Furthermore, the stereoscopic imaging device according to the present invention can provide listeners and target audiences in the fields of medicine, aerospace and defense, automobiles, media and communications, and education and training with an amazing experience that makes them feel as if 3D content is appearing right there in front of them, and is expected to increase the promotional effect with innovative images.

REFERENCE SIGNS LIST 1: Self-luminous two-dimensional display means 1a: Front display panel 1b: Rear display panel 1c: Panel support 2: Slip ring 3, 3a, 3b: Encoder 4: Coupling 5: Motor (rotation means)
DESCRIPTION OF THE PREFERRED EMBODIMENTS 6: Rotation axis, rotation shaft 7: Rotating base box 10: Control means 20: Storage means 30: Data conversion means 40: Motor control means 100: 3D image device 100A: 3D image device 200: Rotating section 230: Three-dimensional shape data 240: Total voxel data 250: Voxel data representing a cube shape 324: Image sequence 320, 325, 350: Cube cross section 300, 305, 310: Display panel

Claims (20)

a self-luminous two-dimensional display means having a display panel on the front and back sides of a panel support, the display panel having light-emitting elements arranged vertically and horizontally to form pixels, for emitting and displaying an image;
a rotation means for rotating the display panel around a rotation axis passing through a center of the panel support, the rotation means having at least one of an upper support shaft supporting an approximately middle portion of an upper end portion of the panel support and a lower support shaft supporting an approximately middle portion of a lower end portion of the panel support;
a control means for performing voxel drawing based on a position where each of the light emitting elements comes to a voxel according to a rotation angle of the display panel;
The rotation axis is located at a position spaced forward or backward by a required small distance from the display surface of the front display panel,
a display panel disposed on the front side such that a distance from the display panel to the axis of rotation is different from a distance from the display panel to the axis of rotation. 2. The stereoscopic image device according to claim 1 , wherein the rotation axes are parallel to a column direction of the light emitting elements arranged vertically and horizontally on the display panel. 2. The stereoscopic image display device according to claim 1 , wherein the axis of rotation is inclined at a required small angle to the right or left with respect to the column direction of the light emitting elements arranged vertically and horizontally on the display panel. The stereoscopic imaging device according to claim 1, wherein the axis of rotation is located at a position that is 4% or more of the horizontal length of the panel from the display surface of either the first display panel associated with the front side or the second display panel associated with the back side. The stereoscopic imaging device according to claim 1, wherein the axis of rotation is located at a distance corresponding to 8%-16% of the horizontal length of the panel from the display surface of either the first display panel associated with the front side or the second display panel associated with the back side. The three-dimensional image device according to claim 1, wherein the self-luminous two-dimensional display means has a phase difference of 180 degrees between the front display panel and the rear display panel with respect to the axis of rotation. 7. The stereoscopic image device according to claim 6 , wherein the self-luminous two-dimensional display means has light-emitting element arrangements shifted by subpixels between the front display panel and the rear display panel in the vertical and/or horizontal directions. 7. The stereoscopic image device according to claim 6, wherein the axis of rotation is disposed so that a distance from the axis of rotation to the front side of the display panel is different from a distance from the axis of rotation to the rear side of the display panel. 9. The stereoscopic image display device according to claim 8 , wherein the axis of rotation is disposed on a display surface of either one of the front display panel and the rear display panel. 10. A stereoscopic image device, comprising: a display panel for displaying images on both sides of the display panel according to claim 9 ; and a light diffusing element disposed only on the display panel that coincides with the axis of rotation of the display panel. 2. The stereoscopic image device according to claim 1, wherein the control means increases the frame rate on the outer side of the rotation of the display panel and decreases the frame rate in the area closer to the center in order to achieve a uniform voxel density over the entire surface of the display panel. 2. The stereoscopic image display device according to claim 1 , wherein said control means performs interlaced drawing when performing said voxel drawing. 2. The stereoscopic imaging device according to claim 1, wherein the control means detects the position of the viewpoint and/or face of a person located around the self-luminous two-dimensional display means and expands the voxels to the rear side from the viewpoint. The stereoscopic image display device according to claim 13 , wherein dithering is performed using the expanded voxels. 2. The stereoscopic imaging device according to claim 1, wherein the control means is configured to detect the position of the viewpoint and/or face of a person present around the self-luminous two-dimensional display means, and to prevent see-through by controlling so as not to display any voxels other than those initially visible from that position . 16. The stereoscopic imaging device of claim 15, wherein the detection target is a face, and when the number of detections is 1, a one-person mode is set; when the number of detections is 2 or more but less than a certain value, a mode is set in which only the first visible voxel obtained by ORing all of the detected voxels is drawn; and when the number of detections is more than a certain value, a everyone mode is set, in which no hidden surface processing dependent on the viewpoint angle is performed. 2. The three-dimensional imaging device according to claim 1, wherein the self-luminous two-dimensional display means has a configuration in which a plurality of light-emitting elements having different luminous colors each constitute one pixel, and the plurality of light-emitting elements constituting one pixel are arranged in a row along the axis of rotation, and has a function of displaying a color image. 2. The stereoscopic image device according to claim 1, wherein the control means is provided in a rotating section and configured to control the synchronous display of images on the display panel, and a motor control means is provided in a non-rotating section for synchronously controlling a motor rotation speed. a self-luminous two-dimensional display means having a display panel on the front side of a panel support, the display panel having light-emitting elements arranged vertically and horizontally to form pixels, for emitting and displaying an image;
a rotation means for rotating the display panel around a rotation axis passing through a center of the panel support, the rotation means having at least one of an upper support shaft supporting an approximately middle portion of an upper end portion of the panel support and a lower support shaft supporting an approximately middle portion of a lower end portion of the panel support;
a control means for performing voxel drawing based on a position where each of the light emitting elements comes to a voxel according to a rotation angle of the display panel;
The rotation axis is located at a position that coincides with the display surface of the front-side display panel, and is tilted 5 to 12 degrees to the right or left with respect to the vertical column direction of the light-emitting elements arranged vertically and horizontally on the display panel, thereby increasing vertical resolution. a self-luminous two-dimensional display means having a display panel on the front side of a panel support, the display panel having light-emitting elements arranged vertically and horizontally to form pixels, for emitting and displaying an image;
a rotation means for rotating the display panel around a rotation axis passing through a center of the panel support, the rotation means having at least one of an upper support shaft supporting an approximately middle portion of an upper end portion of the panel support and a lower support shaft supporting an approximately middle portion of a lower end portion of the panel support;
a control means for performing voxel drawing based on a position where each of the light emitting elements comes to a voxel according to a rotation angle of the display panel;
The self-luminous two-dimensional display means is a stereoscopic imaging device characterized in that a display panel is also provided on the back side of the panel support, the front-side display panel and the back-side display panel are out of phase with each other by 180 degrees with respect to the rotation axis, and the arrangement of light-emitting elements of the front-side display panel and the back-side display panel are shifted by a subpixel in the vertical and/or horizontal directions.

Images