DE3048378A1 - Stereo image prodn. system - involves simultaneous projection of adjacently taken negatives onto screen via magnifying lens and lenticular grating - Google Patents

Abstract

The arrangement is intended for producing a stereo image (4,4'). It is observable without a viewing aid, and is produced by projecting (1) a number of two-dimensional photographs of an object, taken from adjacent positions, onto a screen (3) or light-sensitive surface in front of which a lenticular grating (2) is arranged with a predetermined grating width and a number of linear image bands. The negatives are simultaneously projected using a projection system whose light path is optically identical to that used for their initial exposure. A common large-aperture image-forming lens (5) is arranged adjacent to the projection objectives (1) to transform the integral spatial image in transverse and axial direction to obtain the required magnification as observed in the region of the grating (2).

Description

Device for assembling free-eyed (objective)

Observable stereo raster images The invention relates to an apparatus for assembling freely-eyed (objectively) observable stereo raster images a number of two-dimensional, recorded from respectively neighboring starting points Individual views of an object with their negatives at a distance from each other preferably positioned on a tape of film and aligned with a reference point projected onto a screen or a light-sensitive surface the a lenticular or lens element screen with a fixed grid width and is arranged with a plurality of linear image bands.

Devices with these generic features are known.

The creation of supervisory signs that appear three-dimensional without viewing aid is currently mainly carried out according to the lenticular stereo method. in the The principle of lenticular stereoscopy is based on the fact that it is reversible Cleomctrisch-optical beam length. A lenticular grid focuses on each incident Light bundle approximately in its focal plane. No matter whether it is in this one Focal plane a cli! fus reflective scattering layer (projection method) or a photographic or other storage layer (for a permanent image) arranged are, the inversion of the beam path leads to the incident or stored Light wave field according to direction and intensity is exactly reproduced with it the necessary condition for completely reconstructing the three-dimensional image space Fulfills.

If you now project a real, spatial image with the Bezuq the viewing direction reverse light direction (one speaks of pseudoscopic When projecting) onto the lenticular lens, this can be done in the retrograde beam path spatial image of the object can be observed. As a result of the complete reversal of the beam path, the real image of the projection optics is also reconstructed, whereby a bundle delimitation occurs in the observer space. This is expressed in that the object only through the reconstructed exit pupils of the projection beam path can be seen.

From this it follows that the generation of the real pseudoscopic aerial image in the simplest case can also be done by a single stereo image pair, with the image quality is not impaired, only a limitation the viewing possibility occurs.

The ideal dimensioning of a raster image for evenly sharp and interference-free reproduction of the entire object space from zero to infinity from derive the number of lines of the lens grid used, with which the resolution in the image plane is fixed. Here it simply holds that for a given number of Raster elements in the image area are resolved by each individual raster lens Number of pixels and the number of points used to generate the pseudoscopic aerial image The partial images used must be identical to one another. With a rough grid from 2 to Such requirements have already been met with a lens diameter of 3 mm. These Basically, considerations apply to both spherical and cylindrical lens grids applicable. In the latter case, the generation of the pseudoscopic is reduced However, the projection arrangement required for the aerial image is on a row of images, the vertical parallax effect is eliminated.

The idealized properties of lenticular stereoscopy will be in practice by the imperfections of the grid as well as by that actually usable resolving power of the photo emulsion is largely limited. Important for the quality of the generated raster images is the design of the exposure arrangement.

When exposing the partial negatives on the lenticular material must in order to obtain the desired parallax values in the plane of the paper Angular relationships between the individual beam paths in relation to the recording beam path to be changed. Complicated adjustment devices or sequential ones are required for this Exposure Devices for the exact control of the displacement movements for the individual lenses necessary. In connection with known devices, these are required Calculation measures are given for this.

However, if one proceeds from the principle of unchanged Reversal of the recording beam path, this may result in a imperfect, but geometrically exactly true to scale, pseudoscopic real Spatial image at the location of the subject. A direct record of this faithful to the original The spatial image is in principle possible and has already been implemented. At a simple cylinder lens grid supervision method, however, this is for reasons of nufliisunqs not feasible, as only the effect of the narrow frame of the picture format limited eyes to a distant, deeply staggered scene.

This gave rise to the object on which the invention is based, this To overcome difficulties and the projection optical system accordingly to change that a simple adjustment of the position and size of the room image is possible.

This object is achieved in that in a device with the Features of the generic part of claim 1 according to the invention in his Measures specified in the labeling section are applied jointly.

What is noticeable about the invention is that only through the connection of the two measures, namely that the individual partial negatives together in one single-stage working projection device under a multiple projection system Use of an optical design which is optically identical to the recording beam path System are exposed and that adjacent in the multiple projection system a common, additional imaging lens larger than the projection lenses Opening is arranged as a means for transforming both transversely and longitudinally of the integral spatial image with the desired scale in the vicinity of the grid plane, the Solution given for a simple possibility of setting the position and size of the room image is. The choice of the lens focal length and the distances can be used within limits The location and size of the room image can be influenced.

For the image distance of each level of the transformed spatial image, gitt namely, with the appropriate sign, simply the lens formula. The influence of the additional refractive power of the lens on the two-dimensional image of the partial negative is generally negligible, it can be made possible by refocusing the projection optics be balanced.

The invention is explained with reference to the drawings. In the drawings represent: FIG. 1 the imaging principle for the pseudoscopic generation of a Spatial image by means of an identical to the recording beam path, however inverted optical system, Figure 2 schematically shows the inventive optical Projection system for raster images.

Projection optics 1 of a multiple projection system form the individual negatives with the different views of the object and one in the projection beam path The lenticular grid 2 located here focuses each incident light bundle in its focal plane 3. It does not matter whether there is a diffusely reflecting scattering layer in level 3 (projection method) or a photographic or other storage layer (permanent image) is arranged is, the inversion of the beam path leads to the incident or stored Light wave field is reproduced exactly according to direction and intensity, so that in retrograde beam path the spatial image 4 of the object can be observed.

Since, as a result of the complete reversal of the beam path, the real image of the projection optics 1 is reconstructed, occurs in the observer room a beam delimitation so that the object only passes through the (reconstructed) exit pupils of the projection beam path can be seen. Incidentally, Ilicraus surrenders, that the generation of the real pseudoscopic aerial image 4 In the simplest case can also take place through a stereo image pair, with no impairment of the image quality, but only a strong restriction of the viewing options occurs.

When exposing the partial negatives onto the lenticular material In order to obtain the desired parallax values in the plane of the paper, the angular relationships must be changed between the individual beam paths in relation to the recording beam path will. In known devices of the type indicated, this is done by complicated Adjusting devices or, in the case of sequential exposure, by precisely controlled Verschiebebewegunqen, based on appropriate calculations according to a known scheme can be realized.

In contrast, the invention is in the projection beam path in the vicinity of the projection optics 1 an additional common imaging lens 5 (Fig. 2) arranged with a large opening, the focal length of which is indicated by f. With this Lens, the desired change in scale and parallax is achieved in one step (Picture 4 'in Fig. 2).

For the image distance b of each level of the transformed spatial image 4 ' the simple lens formula applies with the appropriate sign.

1 + 1 s 1 ~ ~ a b f b = a'f a + f One through the additional refractive power of the lens 5 noticeable influence on the two-dimensional The representation of the partial negatives is generally negligible; however, he can get through Refocusing the projection optics 1 are compensated.

These relationships are illustrated using a specific dimensioning example clarifies, which shows that there are suitable combinations of the elements of the optical Let systems find.

This exemplary embodiment is the recording with a double row of lenticular lenses of 16 individual lenses with intermediate apertures 1: 8 as a basis, furthermore an overall basis of 86.25 mm, a lens focal length of 17.70 mm and a negative width of 5.75 mm.

It is projected at a distance of 230 mm on a format of 75 x 105 mm2.

If you use a cylinder lens grid with the focal ratio 1: 2, this results in a utilization of 82 8 of the viewing angle, i.e. H. to the Narrow unexposed zones remain at both limits of the viewing area.

For the additional imaging lens 5, the focal length, f = 200 mm with a used opening of 92 mm.

This is calculated from the lens formula given above an image of the entire object space from 1.5 m to infinity on an apparent one Room depth of b = 23.5 mm in the raster image. This area can at least for the image plane symmetrical division with the usual lens grids and photo materials are still sufficient be reproduced sharply.

With regard to the imaging lens 5 is still to be required that they at an aperture ratio of 1: 2.2 and an angle of view of 200 depending on the used Resolves grid constant of approx. 2 to 5 L / mm. This is generally done with simple Lenses to be achieved: however, the use is also special for this purpose corrected, compound lens systems possible.

Claims (2)

Claims 1. Device for assembling freläugig (objective) observable stereo raster images from a number of two-dimensional, from each neighboring starting points recorded individual views of an object, their Negatives preferably positioned at a distance from one another on a film strip are and aligned with a reference point on a screen or a light-sensitive surface are projected, over which a lenticular or lens element screen with a fixed grid width W and with a large number of linear image bands is arranged, characterized by the combination of features a) the individual Partial negatives are produced together by means of a single-stage projection device a multiple projection system (1) using with the recording beam path exposed optically identical optical systems, b) in the multiple projection system (1) An additional, common imaging lens is adjacent to the projection lenses (5) large opening as a means to both transversal and longitudinal Transforming the integral spatial image with the desired scale into the vicinity the grid level (2) arranged. 2. Apparatus according to claim 1, characterized in that alone by dimensioning the focal length and the spacing of the additional lens (5) the elements of the optical system (1) both the position and the size of the spatial image can be influenced within limits.