Note: Descriptions are shown in the official language in which they were submitted.
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Description
1. Device for the creation of three-dimensional pictures.
s
2. The invention concerns a picture-carrier for tlhe generation of auto-
stereoscopically observed pictures which give perspective views of the
recorded field of view of the object.
3. US 4 571 616 and DE 35 29 819 describe projection devices which
have static screen surfaces in which the screen is grouped in cylindrical
lens-shaped rasters so as to create stereoscopic pictures. In this
process, pictures are split into vertical lines anc~ projected onto the back
of the screen. The lines can then be directionally selected through the
~s cylinder lens set in front of them, with the result that the observer is
provided with the effect of viewing a spatial picture. Anaglyph
procedures are also known in which two latera111y displaced and
superimposed projected images create a three-dimensional effect.
Here the two projected images are viewed with the aid of colour filter
ao spectacles, whose lenses are coloured in the same colours as the two
projected pictures. Another recognised technique is that of shutter-
spectacles, which create a three-dimensional picture by releasing the
view of the screen to the right and then to the left eye at separate
intervals, and in synchronisation with the screen presentation.
as Another well-known device is the three-dimensional display described in
JP 07 - 64 020. In this, several simple objective lenses are placed on a
display surface. They include a convex lens with a short focal length, a
light source, and an elastic drive positioned between the two. Using the
flexible drive allows the distance between the convex lens and the light
source to be varied. This changes the position of the image of the light
source conveyed through the convex lens, and so produces imaginary
pictures. The device also permits these simple objective lenses to be
arranged in geometric shapes, e.g. cylindrical or ball-shaped bodies, so
that the projection of the imaginary 'front or re<~r picture' can be made
3s available to the observer through a field of ob~;ervation of 360°.
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In this type of direct projection technique for thE; eye, the estimate of
distance of an object is related to the size of its perceived image.
These techniques call up perceived images whiich appear to be spatial,
using zooming techniques by means of simple objective lenses. They
s use a perceptivelpsychological effect (without tlhe use of spectacles or
similar aids), which is based on an empirical, visually attained
memorisation.
US 5793918 describes a device with light-conducting optics /glass
fibres which can be moved longitudinally by means of drives, and which
~o are mounted on a curved display / projector, and transmit the picture
which is created in the background by this projector to the observer at
the device's - / relief surface.
The glass fibres and their related motive drives which are mounted on
this curved screen I projector are grouped together (in the direction of
~s the observer), and are moved by a holding device so that they create a
height-structured surface, comparable to a real object.
4. One disadvantage of the anaglyph procedurE: referred to above, is the
high loss of colour components. With the shunter-spectacle device
ao described earlier, there is the disadvantage that special glasses have to
be worn, and that, because of the way the picture is divided, only half of
the picture refresh rate can be used. Further, with US 4 571 616 and
DE 35 29 819 the three-dimensional picture efi~ect is proportionally
restricted, in that the viewing angle and the distance to the screen are
zs changed so as to be able to perceive larger spatial perspectives of the
picture object. With this latter procedure, greater technical input is
necessary, in order so to increase the spatial picture effect, that
concealed picture contents can be transmitted to the observer. This is
done by either replicating the vertical lines to create additional
3o projections, or by modifying them to the observation position
(calculation}. A disadvantage of this procedurE~ is that the stereoscopic
effects are lost if the screen is turned around a~ screen orthogonal. This
disadvantage comes into effect with rotatable screens or screens with
horizontal screen surfaces ('Responsive Worklbench' - Chip 5198
3s S.32), which are used by several observers at the same time. With the
procedures mentioned above,
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with the exception of the shutter-technique, only the most diverse
variations of vertical line raster procedures come into play.
The method of direct projection techniques using simple objective
lenses, when compared to the above procedures, leads to substantial
s reductions in quality for a greater technical and financial expenditure,
and this substantially increases with the increa:~ing complexity of the
picture contents to be conveyed.
This enormous financial outlay is substantially iincreased with devices
that are based on US 5793918, together which also give rise to
ao increasing productive effort and decreasing quality of the picture
representation.
This is explained by the fact that a complicated) optical mechanism is
mounted on a specially curved screen I projector.
This screen / projector creates pictures in the background, which are to
~s be conveyed to the observer by means of height-adjustable optics
glass fibres. Since however the non-light conducting drives as well as
the light-conducting optics have to be mounted' on the screen I
projector, the screen / projector must have a vE~ry large surface and
must be curved (at considerable effort), in order to shape it in a form
ao suitable for use.
Added to this is the problem that the picture for this complex,
universally-curved screen I projector has to be specially computed, in
order to compensate for the comparitively IargE: resulting blind spots of
the drive supports opposite the glass fibres thE:mselves.
2s The physical characteristics of the optics / gla~~s fibres mounted on the
screen I projector also lead to the disadvantage that only a very low rate
of 1124 second can be achieved. This is directly related to the
development of longitudinal oscillations in the fibres. This fibre
oscillation carries through to the ends of the picture relief and appears
3o as uncontrollable surface resonances with every change in position.
These surface resonances cannot be prevented by the bundling
mentioned earlier. The guidance grid which is provided to stabilise the
ends of the glass fibres tends to favour this negative effect through the
guide opening tolerances provided.
3s The unintended surface resonances cause an irritating image
perception to the observer (whip effect), which become stronger with
increasing
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picture relief depths and more complex, rapidly changing picture
contents with sharp sloping surfaces.
If one were for example to move a simulated grid over the image area,
considerable changes in height of the glass fibres are needed at short
s intervals to each other in order to do justice to the displayed object.
This leads to a high static charging of the glass, fibres, and causes the
related field effects and the production of heat. All these either have to
be critically determined in all the components referred to which concern
the observer and his contact with them, or havE; to be resolved at further
financial expenditure.
It can be concluded from the above that, in order to keep undesirable
side-effects to a minimum, only limited picture contents can be
represented and these only in a time-restricted cycle of the standard
picture refresh frequencies.
~s This time-restricted cycle is also a result of the need to continually
measure the positions of the individual glass fibres, compare them with
the planned position and then correct them.
Zo 5. Given the present status of the technology, the need is to develop an
electronic screen, without mechanically driven optics, and with a
shallow construction depth, whose screen surface can be structured
with a high frequency, and in which the light foir the representation of
the picture can be directly generated in the screen surface, so that all
as the drives lie behind the screen generation surface, in order to create a
three-dimensional picture, in which no separate technical aids are
needed to perceive the picture depth. The screen surface also has to
be so formed that no fixed position of the observer is called for, that
changes in the position of the observer do not call for the calculation of
3o a new picture, and that both are possible without restricting the quality
of the perceived image. At the same time the tereoscopic effect must
remain present even when the screen is pivotE;d around a screen
orthogonal.
3s 6. This task may be solved by inventing a device which is developed in
accordance with the defining characteristics of claim 1.
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7. The screen should preferably be formed from single LED-segments
(pixels), where each pixel can generate the thrE;e additive primary
colours. As an alternative to using LED's for the pixels, other light
generators of suitable dimensions may be usedl as the optically active
s elements. Each single pixel is mounted on the head of a height-
adjustable pixel-carrier. These pixels can be moved to different heights
(pixel heights) independently of each other by controlling the pixel-
carriers. The pixel heights have different zero-positions (these
correspond to the zero level) and can be moved to different pixel
heights in the direction towards and away from the observer. The zero
position is not necessarily identical with the starting position, since the
pixel levels can be moved to a planned position, which then forms the
corresponding zero level. With suitable control instructions the pixels
can be lowered and /or raised below or above t;he zero level. The pixel
~s carrier can for example be so shaped, that it consists of several piezo-
crystals connected in layers, so that a cumulative height effect can be
obtained through suitable control instructions. These height effects can
be produced at the zero level and at the starting position, as well as in
the direction towards and away from the obsen~er. In this way the
ao spatial depth information from e.g. a z-buffer c<~n be proportionally
converted into pixel heights, that is without any other intermediate
steps. With other applications (e.g. stadium diaplays, advertising
billboards etc.), other motive units with suitable: short control times (e.g.
using other field-electrical effects etc.) can be used instead of the piezo-
as crystals referred to.
8. The advantages of the invention are to be found in the fact that the
standard flat screen techniques, such as in e.g. LED-flat screens, can
be directly utilised, since transport motors can be placed behind each
3o single pixel of this LED surface and thus the LED's can be placed at
different heights to each other.
The resulting height profile provides a clear spatial depth perception of
the picture signal when observed from the side, and also when seen
from all other viewing positions.
3s With the presently available computing technology, the data on picture
depth can thus
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be used directly (stored e.g. in the z-buffer of 3--D graphic cards), so as
to convert the data into relief-type picture depths - i.e, the picture colour
signal combines with the picture depth of the object (represented
through the pixel heights) to give a picture with a new quality. This new
s quality of picture results from the physical reali:>ation of the z-axis of
the
mathematical model (as stored e.g. in the z-buffers referred to),
multiplied by the standardised factor.
The greater the difference in height level and its breakdown into single
levels, the greater is the possibility of generating an actual spatial
depth, which corresponds to the depth simulatE;d by colouration and
brightness. In addition, it is possible to set piezo-crystals into high-
frequency oscillations and so to overlayer the image data such that
images can be transmitted to the observer which can be computed or
perceived from different positions, i.e. that every relief structure can be
~s assigned to a picture element at a synchronised rate.
The term 'relief structure' used above is defined by the screen surface
formed by the pixel matrix with a pre-determined height for each
individual pixel.
Through the use of conventional flat screen production techniques (e.g.
Zo as for LED-flat screens) a high unit rate of procluction can be achieved
at a low cost.
9. An example of the application is given diagrammatically in Figure 1.
This shows a single LED-segment from a device for the generation of
as three-dimensional pictures. In this, the pixel-c<~rrier (3) contains a
piezo-element (1 ), which on application of a voltage extends in the
direction (7) of the observer position. The pixel-carrier (3) has a foot
(6), over which a further piezo-element (2) extE;nds like a cloak, and
which bears at its end the whole mechanism and which is fixed at one
3o end to an assembly board (4) and which permits a further basic
movement (8) away from the observer. The pixel-carrier (3) has as a
pixel (12) a light-source-generating head which is formed from three
LED's (5) in the colours red, green and blue. The whole device for the
generation of three-dimensional images consists in this case e.g. (for
3s the application as an advertising board) of a relatively large 480 x 270
matrix of the segments referred to. Its size is '160 cm x 90 cm.
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As a further example of an application, Figure 2 shows the schematic
representation of a single LED-segment of a device for the generation of
three-dimensional images, in which the pixel-carrier (3) runs through
three linearly arranged electrical coils (9). The pixel-carrier (3) has as a
s pixel (12) a light-source-generating head which is formed from three
LED's (5) in the colours red, green and blue. An iron core (10) is
integrated in the pixel carrier. The head is positioned at the appropriate
height level by the action of the electrical coils on the iron core. In
addition the pixel carrier (3) also has a coil spring (11 ) which moves the
m pixel carrier back to the starting position when it is not being controlled.
