DE3421513C1 - Arrangement for generating a stereoscopic impression when viewing images - Google Patents

Abstract

The basic approach in generating a stereoscopic effect when viewing images is to offer the same image to both eyes of the viewer in a customary way, and for the image for one eye to be obscured in a narrow strip on the left-hand image edge and the image for the other eye to be obscured on the right-hand image edge, so that the left-hand image edge for one eye and the right-hand image edge for the other eye appear to be shifted towards the interior of the image. Depending on the assignment of the obscuration to the right-hand or left-hand eye, two stereoscopic effects can be generated. The obscuration can be performed by means of polarising strips when polarising spectacles are used. Dark edge strips are to be provided outside the polarising strips and lighter edge strips adjacent thereto for the purpose of generating the second stereoscopic effect. The undesirable sudden change in brightness between the polarising strips in their passband and the interior of the image can be avoided by means of additional attenuating strips. The method can be applied in the case of television, slide projection, films, or when viewing images or photographs. It is compatible in the sense that a viewer without stereoscopic spectacles sees the image in the normal way and - except for the narrow edge region - without any loss in quality.

Description

Processes have also become known (Offenlegungsschriften DE 32 03 339 A1, DE 32 14 327 A1, DE 3205483 Al, DE 30 50 605 Al), in which only one image is used, but this image in its entirety Image area is modified to separate different partial images for the two eyes to obtain.

This modification can be done by vertical or horizontal polarization strips can be achieved, as in the case of the first-mentioned disclosure documents, or by a modified beam path with the help of a wavy diffractive plate in front of the screen, as in the case of the latter publication.

Another method that works with red-green glasses (test 7/83 p. 622 and Test 5/84 p. 402), delays the red color information in the television set with the help of an electronic circuit so that the red image parts to the right be moved.

This method is therefore not compatible for a normal observer, apart from the fact that all procedures with color separation for both eyes are too different Color adaptations lead, which felt very uncomfortable because of the long-term effect will.

All of the aforementioned methods leave compatibility with a normal one Miss viewers. They are still considerably more complex than the procedure according to the present invention as they modify the entire image while in the method according to the invention only a small image modification on the right and left edge of the image is made and the rest of the image remains unchanged. It a so-called "frame effect" is also known, whereby the picture or the picture wall surface a somewhat smaller frame is placed in front of it, so that when viewed with the frame in front of the picture appears in both eyes, creating a pseudo-stereo effect is achieved. It is also still known to artificially create this frame effect to produce that on the left and right edge of the picture each a polarization strip different Polarization is provided and that the image is viewed with polarizing glasses (DE-AS 1096064 / US-PS 3597042).

This frame effect also gives the impression that the picture goes through a window is seen (which is why it is also known as a "window effect") particularly three-dimensional stereo impression. According to the invention, an arrangement is to be created that go beyond this "frame effect" to create a second steroid effect which is referred to as the "background effect" in the following the generally relatively even background subjectively behind the image plane shifted while the actual image structures remain in the image plane. This creates a particularly natural and three-dimensional stereo effect with a difference in depth of the foreground and background, just like a natural scene is equivalent to. (The creation of this second stereo effect is explained in the description from F i g. 3 explained in more detail.) The object on which the invention is based exists thus in creating an arrangement that (essentially) unchanged the interior of the picture so that the compatibility with a normal picture viewer (without stereo glasses) is given and a stereo impression both as a "frame effect" (system A) and also made possible as a »background effect« (system B).

This is achieved according to the invention in that each at the outer edge The polarization stripe has a darker edge strip and then a lighter one Strip is provided. (The outermost lighter edge strip can also be called a larger Frame). When viewing with polarized glasses appears then depending on the assignment of the polarization of strips and lenses once the "Frame effect" (system A) and when exchanging (or rotating or tilting the lenses) the "background effect" (system B).

The arrangements according to the invention are shown in the following pictures shown: F i g. 1 shows the principle of the invention, FIG. 2 shows a sketch for calculating the stereo effect according to system A ("frame effect"), FIG. 3 shows a sketch for the calculation of the stereo effect according to system B ("background effect"), F i g. 4 shows symmetrical polarization glasses, FIG. 5 shows the application of the invention in a television screen, FIG. 6 shows two strips of film for Attachment to the left and right edge of a television screen, FIG. 7 shows a television picture tube in which the modification according to the invention is permanently installed is.

In Fig. 1 represents 1 the picture, and 2 denotes the edge of the picture, which is usually (especially with television) darker than the picture or its Background is. The two narrow vertical edge strips 3 and 4 darken this Image, namely 3 for one eye and 4 for the other eye, so that these marginal strips about as dark as the black edge strips 5 and 6 that adjoin to the outside be seen. This can be done by using polarization foils with mutually orthogonal Polarization can be achieved with the observer wearing polarizing glasses. The left stripe (3) can be used for the left eye and the right stripe (4) be dark to the right eye, d. H. lie in the blocking area, with the polarization strip is effective as a polarizer and the polarizing glasses as an analyzer.

As a result, the jump in brightness, i.e. H. the edge of the picture on the left Eye, shifted a little to the right and in the right eye a little to the left. Through this the frame appears in front of the picture, which creates a clear stereo effect (System A).

A second, much more natural stereo effect is achieved when the right stripe for the left eye and the left stripe for the right eye is darkened (system B). In this case, the jump in brightness appears The edge of the image is shifted to the rear, which means that the background of the image is clear appears to be shifted backwards, creating a three-dimensional stereo effect will.

The stereo effect according to system A is very clear and also immediately available to an inexperienced observer. The stereo effect according to system B can only be perceived, however, if a further jump in brightness is planned created between the dark and the lighter edge strip (5/2 or 6/2) will.

The creation of both stereo effects is explained below and their size calculated: In the two sketches F i g. 2 and FIG. 3 denotes 1 the dark edge stripes, 2 the polarization stripes and 3 the eyes of the beholder. P is the pixel that perceives the jump in brightness - image versus dark Edge strips - indicates. Only the central rays are drawn.

In Fig. 2 is the right to achieve the stereo effect according to system A Polarization strips blocked for the right eye and in the transmission area for the left eye. This will extend the dark border for the right eye and encompass the area 1 and 2, while edge 1 is seen from the left eye. the aspiration with the polarization glasses. This attenuation can be after the interior of the image decrease too steadily down to the value zero, which is generally imperceptible.

For the two systems A and B you first need two different ones Polarizing glasses. According to FIG. 4, however, one can also use a single pair of polarization glasses use, which is preferably symmetrical.

In Figure 4, 1 denotes the body of the glasses, 2 the temple and 3 the polarizing lens or the polarization film with polarization orthogonal for both eyes. The eyeglass body 1 and the bracket 2 are designed symmetrically. Causes the glasses in one position System A, this is how it causes system B to be placed the wrong way round swap the polarization filters for both eyes, with the simultaneous Turning around 1800 has no influence on the polarization effect.

Instead of symmetrical temples 2, normal ones from around 1800 can also be used are rotatable, can be used.

Instead of symmetrical polarization glasses you can also use one Use normal asymmetrical ones, but with the lenses or the Can twist polarization foils by 90 ". This changes the direction of polarization swapped for both eyes, which makes it possible to switch from system A to system B. is.

Fig. 5 shows the application of the invention to a television set. Here 1 is the inner part of the image, which remains unchanged, 2 and 3 are the polarization strips with different (orthogonal) polarization, 4 and 5 are the two dark ones Edge strip and 6 the lighter outer edge of the picture.

Figure 6 shows an arrangement of the invention in the form of strip foils which are glued to the right and left edges of a television screen can. Here, 1 denotes the polarizing film. 2 the dark edge strip and 3 the lighter edge strip. The latter would be avoidable if the television housing has a sufficiently light tint.

Fig. 7 finally shows a television picture tube in which after a Another feature of the invention, the polarization strips 1 and the dark edge strips 2 are firmly integrated in the glass body 3 of the tube. The transparency in the inner image part preferably equal to the transparency of the two polarization strips be in their transmission range when viewed with polarized glasses.

The inventive idea was preferably based on the example of the arrangement for the television screen. It goes without saying that the Arrangements for any screen, e.g. B. for operation with a video recorder, apply in the same way. However, the application of the invention is not limited to but applies very generally to viewing images, especially slides and films or photo images. For this purpose, foils according to FIG. 1, FIG. 5 or FIG. 6 can be used be used. In the case of slide projection, the foils can also be used with the Slides are framed, or frames are used that already have the slides contain. In the case of slide or film projection, the foils can be in the image plane in front of or behind the slide, respectively. Film must already be built into the projector. Alternatively a second image plane can be generated by the beam path and the foils in this second image plane can be introduced. There is a change in slide projection of the foils for lengthways or landscape format necessary.

This can be done using two different foils, which are alternative be introduced. Instead, the rays drawn can mark the Direction of the jump in brightness (edge) for the two eyes.

They meet at point P, which is in front of the image, creating the edge moved forward appears. This edge is associated with the outer frame, which appears to be shifted forward as a whole.

This results in the "window effect" as if the picture were through a front window would be considered.

In Fig. 3 is to achieve the stereo effect according to system B of the right polarization strip permeable for the right eye and for the left eye locked. As a result, the jump in brightness appears between the edge of the picture and the dark one Edge strip to point P offset behind the image plane. Then subjective appears the (relatively even) image background in the depth of point P. This effect However, it is only really pronounced when the outer picture frame is in depth the image plane is perceived lying down. This is due to the further jump in brightness reached between the darker and lighter outer marginal strip. The same applies the other image structures, so that a deep separation of background and Content is perceived, which creates a natural stereo effect. This In contrast to the “frame effect”, the »background effect« is not created with mechanical means (a prefixed frame). It is therefore initially surprising and comes only have an immediate effect if the arrangement according to the invention - polarization strips, darker stripe and lighter outer edge stripe - this arrangement is provided also has the advantage that it leaves the inside of the picture essentially unchanged, because the dark and the lighter stripes are outside the actual image. As a result, compatibility for image viewers without stereo glasses is fully met.

In the following, the size of the spatial displacement at F i g. 2 and F i g. 3 calculated. A denotes the distance from P to the left edge of the polarization strip and b is the distance from P to the right eye, y is the interpupillary distance and x is the width of the Because of similar triangles, the following applies: a = b.X y is, for example for the television screen b = 200cm y = 7cm x = 0.7 cm it follows: a = 200 0.7 cm = 20 cm 7 This setting corresponds approximately to normal conditions. By varying the x the stereo effect can be increased or decreased.

Both stereo effects can be improved by that the - in itself undesirable - brightness jump between the two polarization strips in their transmission range and the inside of the image (when viewed with polarized glasses) is avoided. This can be done by placing each polarization strip on the inner edge an image attenuation is provided, the size of the transmission attenuation of the Polarization stripe when loading Foil strips according to FIG. 6 used whose spacing is variable in order to match the width of the image in the case of lengthwise format or Adjust landscape format. The exact position of the strips can be determined with the usual technical Means are regulated electronically.

In the case of a photograph, the film can be placed in front of the picture as a frame be glued to the picture or during the production of the photographic paper be integrated with this firmly connected.

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Claims (12)

Claims: 1. Arrangement for generating a stereo impression when viewing pictures, especially when watching television or film. or slide projection, with a narrow polarization stripe on the left edge of the image when viewed with polarized glasses the image for one eye and at the right edge of the image darkens the image for the other eye, because you marked that on the outer Edge of each polarization stripe a dark edge stripe followed by it on the other hand, a lighter strip is provided. 2. Arrangement according to claim 1, characterized in that two different Polarizing glasses are used, and that the assignment of polarizing strips and polarization glasses are chosen so that one pair of glasses in the right eye the right edge of the image is shifted inwards and accordingly with the left eye the left edge of the image is shifted inwards (system A) and with the second pair of glasses in the right eye the left and in the left eye the right edge of the image inwards is moved (system B). 3. Arrangement according to claim 1, characterized in that a single symmetrical polarization glasses are used, in which one glasses position the Arrangement according to system A and the arrangement in the other (reversed) glasses position according to system B is valid or that a single asymmetrical polarization glasses is used in which the glasses or temples can be twisted or tilted, so that in one position the assignment according to system A and in the other position the Allocation according to system B is set. 4. Arrangement according to claim 1-3, characterized in that the inner At the edge of each polarization stripe, an image attenuation is provided that corresponds to the transmission attenuation of the polarization stripe when viewed with polarization glasses and which after the inside of the picture can decrease too steadily down to the value zero. 5. Arrangement according to claim 1-4, characterized in that for the Television the two polarization strips and the edge strips on a single one transparent film are housed, which is attached in front of the television screen will. 6. Arrangement according to claim 1-4, characterized in that the two Polarizing strips are designed as individual foils, and that these foils be attached to the right and left edge of a television screen. 7. Arrangement according to claim 1-6, characterized in that the polarization strips and the dark edge stripes and preferably the attenuation in the inner image area already built into the glass body during manufacture of the television picture tube are. 8. Arrangement according to claim 1-4, characterized in that for the Projection of slides a film (stereo film) is provided, which the two polarization strips and optionally contains the attenuation for the inner image area, and that this The slide is framed with the slides. 9. Arrangement according to claim 8, characterized in that the stereo film is firmly attached to the slide frame. 10. Arrangement according to claims 1-4 and 8 for the projections of slides or films, characterized in that the stereo film is fixed in the projection device is built in, namely immediately in front of or behind the slide or in a through the beam path of the projector generated second image plane. 11. Arrangement according to claim 1-4, characterized in that for viewing images, preferably photographs, according to a stereo sheet Claim 8 is provided, and that this film is placed on the picture or on the Image is glued. 12. The arrangement according to claim 11, characterized in that the stereo film is already provided for in the photographic paper during its manufacture, so that the photograph is either normal or - when using polarization glasses - can be viewed stereoscopically. The invention relates to an arrangement for generating a stereo impression when viewing images according to the preamble of claim 1, without the need to to provide two fundamentally different images for the left and right eye or to broadcast while watching TV. A real stereoscopic image transmission, for example when watching television requires a different image each for the left and right eye, with the illustration corresponding image points depending on their depth in both eyes in the horizontal direction is shifted against each other. Various methods are known to do both of these to supply different images to both eyes separately. Here is a separation according to colors (red-green, using red-green glasses) or after light polarization (using polarization glasses), or by splitting - for example with prisms or lenses - different beam paths are created intended for both eyes. A disadvantage of these methods is that they are two different Images are needed, which means increased effort and what the television sets double transmission capacity required. Another disadvantage is incompatibility with a normal image viewer that renounces the stereo impression. He sees usually a blurred image if both images - without separating - the two Eyes are fed together. It is the aim of the present invention to avoid both disadvantages and to propose a method and arrangements in which a) uses only one image or is transmitted and b) the compatibility is achieved in the sense that a normal observer the picture (e.g. television picture) without any significant change in the normal way, while an observer with polarized glasses - Depending on the position of these glasses, you can optionally see two stereo effects. With your one The picture frame appears in front of the stereo effect (system A), while the second effect occurs in the the background is noticeably subordinate to the rest of the picture (system B).