WO2015058898A1

WO2015058898A1 - Multi-layered display and associated method for generating images

Info

Publication number: WO2015058898A1
Application number: PCT/EP2014/069334
Authority: WO
Inventors: Klaus Wammes; Maximilian Stromer
Original assignee: Klaus Wammes; Maximilian Stromer
Priority date: 2013-10-25
Filing date: 2014-09-10
Publication date: 2015-04-30
Also published as: DE102013221772A1

Abstract

The invention relates to a multi-layered display comprising at least three imaging layers illuminated by a light source, specifically a back layer, a front layer and at least one middle layer, the back layer, facing the light source, being designed as a grey-scale display, the middle layer being a colour display, and the front layer, facing an observer, being designed as a colour display that has a higher gamut than that of the middle layer.

Description

description

Multi-layer display and associated imaging method

The invention relates to a multi-layer display, also referred to as multilayer display, and basically builds on the technology described in WO 2013/045103 for volumetric imaging.

The object of the invention is to develop this technology to the effect that even with comparatively few image layers and correspondingly low transmission losses, a high-quality 3D representation with real depth effect is realized perpendicular to the image plane in the viewing direction extending image objects - and not just a quasi 3D-like image impression with objects lying one above the other in the different levels.

In this context, the present text in conjunction with the figures describes a configuration for a multilayer display, also referred to as a multilayer display, which is particularly suitable for realizing a combination of volumetric and autostereoscopic 3D display with flowing boundaries between the two extremes, and which even offers the possibility of representing all variations simultaneously in different places (spatially resolved) - and moreover, in all variants of the autostereoscopic display a quasi arbitrary number (only depending on resolution and control of the second layer) of different perspectives horizontally and vertically.

In addition, of course, normal 2D representation and classic 2 or 3-layer representations are possible even without stereoscopic portion.

This approach is in principle possible with three identical or even identical (at least partially transparent) displays of different technologies; a clearly preferred for transmission reasons version is shown schematically in FIG. 1 and comprises the following components: • Layer 1 (back) - is a pure grayscale display

• Layer 2 (center) - is a color display with reduced gamut - and thus improved transmissivity

• Layer 3 (front) - is a classic color display with normal gamut

The image structure in such a display can basically take place in three different operating modes: a) Only volumetric representation in the visible frequency range between 480 nm and 780 nm.

In this case, in each individual preferably three image layers (the principle is not limited to three layers and correspondingly works with higher number of layers) assigned an independent, individually identifiable image content for each image position, which achieves its volumetric image representation in the superimposition of all image layers, and / or each of the preferably three image layers receives only a partial information, which is only at superposition of the image layers by additive and / or subtractive color mixing and / or by actual and / or perceived only by the human perception apparatus interference and / or intensity and / or color changes as an entire volumetric representation. This principle can be implemented monochromatically as well as polychromatically with a resolution of all colors that can be displayed in the visible color space.

By means of a suitable selection of the electro-optical light modulators and / or polarizers and / or light sources, this principle can also be used directly for other wavelengths below 480 nm and / or above 780 nm. b) Only autostereoscopic display in the visible frequency range between 480 nm and 780 nm.

For this purpose, at least in one layer parallax barriers are generated to to ensure that each perceived by the right and left eye image portion is different and with a defined crosstalk share (cross-talk) afflicted, and the partial images that are perceived by the right and left eye to a total image impression, its partial images different perspectives (autostereoscopic presentation).

In addition to the prior art, different configurations can be statically and / or dynamically and / or spatially resolved in this approach and / or spatially resolved as desired.

In addition, the typical disadvantage of the autostereoscopic display-namely, the reduction of the image resolution-can be avoided since the image points (pixels and subpixels) of the imaging display layer available for the image display are divided between the right and left eyes and are further assigned to additional perspectives. to equip the useable viewing position with at least some spatial freedom.

In the preferred approach described here, the superficial resolution of the imaging electrooptically modulatable layer is not split between the right and left eyes and the parallax barriers are generated in a further electrooptically modulatable layer; in addition, a further electrooptically modulatable layer is additionally inserted between these two layers. the resolution of which is statically and / or dynamically the same or preferably 1, 2 to n times greater than that of the first (front) layer. The resolution of the back layer is statically and / or dynamically equal and / or preferably 1, 2 to n times smaller than that of the first layer. This is schematically shown in FIG. 2 to recognize.

This approach is preferred because it involves primary information by means of the front imaging layer and the intensity control of the parallax barriers at the back layer - directly at the light source - and thus the best actual and / or perceived image sharpness can be represented - technically all combinations and / or variations of the individual image-forming and image-influencing layers can be built up and functional.

Thus, for the preferred approach, each light beam passing through the respective eye from a specific perspective view passes through three electro-optical modulators whose functionalities are statically and / or dynamically freely variable and / or whose distance from each other is static and / or dynamic in the z Axes are parallel and / or not parallel to each other and / or whose driving frequencies are statically equal and / or unequal to each other and / or dynamic, following any dependencies, are different from each other.

In this preferred approach, the parallax barriers are not necessarily line-shaped as usual, but in a first example, checkerboard patterns or diagonals. This provides a better spatial representation for the vertical resolution. It should be noted that this embodiment is exemplary only and the design of the parallax barriers static and / or dynamic can be done completely free, according to the assignment resulting from the image task to be displayed and the resulting static and / or dynamic assignments gives the front image-influencing layers.

The interleaving of the two image components in the front imaging plane, which is typical in the prior art, does not take place here, and the halving of the simultaneously displayable different image pixels by the parallax barriers is effected by the intermediate layer with a significantly higher resolution than the barrier pattern Representation of spatially and / or temporally resolved perspectives, clearly overcompensated. For example, in the case of an arrangement in which a matrix on the first layer is assigned a matrix on the interlayer of 10 × 10 (or with corresponding activation at the subpixel level, even 30 × 30 individually controllable subpixels), and for a parallax barrier matrix of, for example, twice the x and y size of the main image information pixels, a resulting overall image detail wealth of up to 225 times the resolution of the main image information pixels is achieved (the maximum achievable maximum resolution only at the actual achievable physical and / or resulting resolution of the intermediate layer and for the currently announced ultra-high-definition resolutions can easily assume values well over 1000). This means that, for example, with a perspective resolution matrix of 6 positions horizontally and 6 positions vertically per beam (viewing angle ranges for each right or left eye), they still allow the "eye-box" - the spatial area from which one or more observers can obtain a spatial image impression - to the extent that more than 6 people at the same time an independent spatial impression of each full horizontal and vertical perspective resolution while maintaining the original main image pixel resolution (= static and / or dynamic resolution of the first imaging layer).

At the same time, this massive increase in the total image pixels that can be displayed also makes it possible to actively reduce crosstalk between left and right eye information (cross-talk), for example by setting the number of viewable resolutions that can be displayed and / or the maximum number of images simultaneously independent of the resolution of the viewing persons, the possibility is obtained that in the rear and / or middle position the respective beam-relevant information areas with a contour of one and / or several subpixels and / or pixels with static and / or dynamic, Surround the actual image content decoupling, electro-optical modulation value. This reduces the available number of Representable image information, for example, in the following relationship: If, in the example given above, a contour consisting of 3 subpixels is placed around the perspective matrix, this results in a maximum overall image detail richness of up to 144 times the resolution of the main information pixels. That is, with still full perspective resolution, the ability to simultaneously render this full perspective and image resolution for more than 6 people at a time, but now only for up to 4 people, is reduced. However, the reproducible and / or perceived image sharpness and brilliance increase by more than 55% by reducing the cross-talk.

The control of the cross-talk can be done statically and / or dynamically. In static operation, individual pixels and / or pixel groups with a fixed intensity value per representable base color (typically R, G, B - but can also other regimes such as R, G, B, W and / or R, G, B, yellow, etc. use) and subpixels driven.

In dynamic operation, the individual pixels and / or pixel groups with a gradually varying intensity value per representable base color (typically R, G, B - but can also be other regimes such as R, G, B, W and / or R, G , B, yellow and / or use any combination of colors resulting from mixing and / or interference from primary colors) and subpixels and / or an intensity value changed in the time pulse-pause ratio per representable base color and subpixel (in the temporal sequence) the respective subpixels at each clock and / or every second and / or every nth and / or a certain rhythm and / or a temporal sequence generated from any dependencies), and / or certain pixels and / or subpixel groups are driven in a fixed and / or dynamically changeable pattern and / or with a gradually changing over time intensity value per representable base color and must it is controlled and / or an intensity value, which is changed in the time-pulse-pause ratio, per representable base color and pattern (in the time interval). Consequently, the respective patterns are driven at every clock and / or every second and / or every nth and / or a certain rhythm and / or a temporal sequence generated from any dependencies. Simultaneous volumetric and autostereoscopic display in the visible frequency range between 480 nm and 780 nm, superimposed in a gradual graduation and / or spatially and / or temporally resolved.

The two operating modes and examples listed above can also be combined in a very different manner as a particularly preferred variant, so that, for example, a permanent 2- or 3-layer representation (in particular according to the existing application WO 2013/045103), such as a moving image. Sequence, for example, in the analysis of medical tomography images, with direct activation of the autostereoscopic overlay for certain image shares, for example, deposited patterns to be found and / or distributed over several layers (and thus 3D) distributed geometries occurs. In this case, the relevant area is superimposed autostereoscopically on the volumetric representation - and at the same time for several people viewing without further aids quasi 3-dimensional representation. And depending on the information density of the available image material can also for the detailed 3D analysis in reducing the number of simultaneous viewers to 1 (a single eye-box), the interesting image areas with z. For example, more than 200 perspectives views can be displayed, while all other image areas can still be overlaid simultaneously and / or volumetrically and autostereoscopically for several observers at the same time and / or can only be displayed autostereoscopically. Other applications, for example in the field of computer-assisted simulations and / or computer games, open up this type of dynamically configurable spatial image display incalculable new possibilities and an order of magnitude improved, more natural spatial representation while at the same time significantly reducing resource consumption compared with holographic representation.

The superimposition is achieved by the fact that the at least three layers are freely controllable for each individual cell - so the information on the first layer can be completed with information from the second and / or the other layers that - depending on the types used imaging layers - this opens up a different characteristic from cell to neighboring cell - and these then give the superimposition in the overall image - and / or actually results in a specific characteristic in the form of direct superimposition, in which the representation of individual cell groups and / or the entire layer behind the first imaging layer is calculated so that the data for the volumetric and the autostereoscopic display are combined and, for example, in temporal order and / or calculated form at the same time on this intermediate layer (in three layers - or distributed on layers at more Layers) and combined with a suitable static and / or dynamic design of the parallax barriers in the backmost layer. This results in a harmonious SD room impression that can be easily processed by the human perception apparatus.

Since all physically present electro-optically image-shaping cells (subpixels) can be addressed and controlled individually and independently of one another in all imaging layers, and the absolute position in the forming x, y, z matrix consists of a different number (preferably 3) of superimposed imaging images Layers and the achievable by electrical control functionality of each cell can be generalized to say that the more cells are available, the more and / or more accurate and / or complex the sum in the forming x, y, z Matrix, such as the number of layers, since the transmittivity per layer is not 100%, and thus a distinct one Reduction of overall image brightness takes place. In order to keep this total image brightness as high as possible, the preferred combination of the individual layers, as already mentioned, is as follows (for operation in combination mode):

- Backmost layer (in front of the main light source): No color representation, only black and white and grayscale - this results in a very good transmissivity. As a further degree of freedom one can reduce the resolution here, if the image task permits this, and thus obtains larger individually controllable cells - with further improved transmissivity.

- Middle layer: Since here the perspective modulation takes place, one needs full color representation - with preferential additive color representation in the total transfer function one can work here with a so-called low-Gamut (thus lower maximally achievable color saturation) version and thus the Transmissivität in comparison to a Significantly increase standard display.

- Front layer: Here, the main image information is displayed, ie here you need full color representation and high-gamut (ie, the best possible maximum achievable color saturation), and thus results in the lowest transmissivity.

With a suitable selection of the currently available and suitable flat displays of various technologies such as LCD, OLED, plasma, EL and / or other flat display technologies, with which it is possible to build electro-optically modulatable cells that have at least a proportion of transparency in these cells, succeeded in achieving a total transmissivity of approx. 1% in a three-layered sample structure. As the flat-panel technologies continue to evolve, this value will continue to improve. This results in an additional important feature, because it is possible - and sometimes even desired - to use different pixel resolutions per layer and / or even different pixel geometries, however, the electro-optical total transfer function must be adapted to the respective configuration of the existing x, y, z matrix can be adjusted. In order to realize the complex overall transfer function, it requires a powerful arithmetic unit (which, however, are quite easily available from the hardware) together with appropriate software that can use such hardware, the required total transfer function also - preferably in real time - calculate and implement.

Depending on the performance of hardware and software, it is also possible to calibrate the resulting multi-layer display by using suitable image pattern representations on the new x, y, z matrix and the comparison of high-resolution images of these image pattern representations corresponding correction factors for each individual cell of the x, y, z matrix calculated and deposited and thus largely tolerances and / or artifacts can be calculated from the resulting representation out.

In FIG. 3 and 4 are summarized once more in principle two different ways to realize a controlled crosstalk (cross-talk) illustrates:

a) By dark (gradual gray scale) controlled areas around the actual perspective zones for even and odd beams (viewing angle areas for each right or left eye) on the backmost layer gives the opportunity to superimpose volumetric and autostereoscopic view for certain viewing angle areas (FIG 3).

b) Areas controlled by dark (gradual gray scale) around the actual perspective zones for even and odd beams (viewing angle areas for each right or left eye) on the middle layer, a similar effect can be achieved, but results in a lower resolution loss (FIG. 4). The preferred distance between the layers depends on the depth to be achieved in volumetric operation and the pixels or beam origins to be displayed per unit area in autostereoscopic operation (number of different perspectives minus the desired number of pixels for controlling the cross-talk). In the examples given here, it is symmetrical 3 mm - but the value can be selected independently for each distance between two imaging layers - depending on the transfer task, the distance between each two adjacent imaging layers is more than 0.2 mm and less than 10 mm - preferably between 1 mm and 5 mm.

Claims

claims

1 . Multi-layer display with at least three illuminated by a light source imaging layers, namely a rear layer, a front layer and at least one middle layer, wherein

- The rear, the light source facing layer as a gray scale display

- the middle layer as a color display, and

- The front, a viewer facing position as a color display with respect to the middle layer larger gamut

is trained.

2. Multi-layer display according to claim 1, wherein the size of the individually controlled pixels of the middle layer is smaller than the size of the individually driven pixels of the front layer.

3. Multi-layer display according to claim 1 or 2, wherein the size of the individually driven pixels of the rear layer is greater than the size of the individually driven pixels of the front layer.

4. A method of operating a multi-layer display according to any one of claims 1 to 3, wherein the backsheet is effective as a parallax barrier with respect to the image content of the front layer, and wherein by the middle layer, a modulation of the perceptible by a viewer depth content the overall picture is made.