FR2655744A1 - Spectacles for 3-D vision - Google Patents

Abstract

A spectacles front, including two transparent lenses whose ratio of the transmission powers varies from 1/10 to 1/100, enables a 3-D sensation to be recreated when observing flat objects. This arises from the physiological production of stereoscopic pairs. The most immediate application is the 3-D vision of ordinary cinema and television images.

Description

FOREWORD
The brain creates the sensation of relief by mixing the corresponding impulses & the simultaneous reception, by the eyes, of two sharp images which are not perfectly identical (binoscopic stereoscopic vision)
Any system giving two offset images thus produces the sensation of the 3rd dimension, independently of the suggestions coming from the effects of perspective or shadows which deceive the eye.

We must therefore distinguish the simple suggestion of relief arising from the devices mentioned above from the SENSATION of relief due to stereoscopic vision which alone can cause physiological reactions such as dizziness or the reflex of recoil.

In fact, for the observer with perfect acuity, therefore symmetrical, the various effects are added to give the sensation of "entering the landscape".

The object of our invention is precisely to enable a subject endowed with binocular vision to see in RELIEF a
OBJECT PLAN or to restore the vision in 3 dimensions of a true relief which is "crushed" by effects of distance of speed or fog ...

We will henceforth designate by the term OBJECT, the images or objects that will be examined by our invention (television screen, cinema, paintings, photographs, real objects or landscapes).

Our invention consists of a spectacle of glasses comprising two glasses, & a priori of the same color but of clearly different transparencies (of the order of 1 & 1/100), the aim being to create a pseudo-stereoscopic couple.

DESCRIPTION OF THE FIGURES
Figure 1 (PLATE I) shows the raking of glasses according to our invention.

FIG. 2 (PLATE I) represents the variant in which the vision zones are surrounded by regions of different transparencies.

Figure 3 (PLATE I) shows a swirl of continuous structure (mask type) with the asymmetries of transparency of the previous figures.

FIG. 4 (plate II) represents a swirl on which, by the rotation of two discs comprising sectors of various transparencies, it is possible to adjust, at its convenience, the transparency of the area deemed to be light as that of the area deemed to be dark.

Figure 5 (PLATE II) highlights the asymmetry of the visual sensations caused, in the shadows, by the asymmetry of transmission of our right and left lenses.

Figure 6 (PLATE II) highlights the stereoscopic couple resulting from the difference in remanence between the two eyes, subject to very asymmetrical light.

Our invention distinguishes two situations
I / STATIC OBJECTS we take advantage of the sensitivity threshold of the daytime eye, that is to say the significant intensity, below which light is not perceived by the brain
Thus, in FIG. 5 a (PLATE II), the left eye, for example, receives the NET image of the object which emits the light intensity I varying from A & A ', above the threshold Sg corresponding to the average luminance of this signal.

Taking into account all the gradations of light and shadow colored or not, for the brain, the apparent dimension of the object is its true size Dg.

For the rest, this eye will be called "clear eye"
In FIG. 5 b, the right eye also clearly receives an image of the same object, an image whose intensity is divided by a factor ranging from 10 & 100. By threshold effect, the distribution B B 'is observed , largely truncated in the shadows, giving the brain the feeling of a reduced size & lower Dd & Dg
For the rest, this eye will be called "dark eye"
The sharp decrease in intensity on one eye does not cause the discomfort that one might fear. Indeed two elements are to be considered - FECHNER's law, valid for the daytime illuminations which concern us, shows that the sensation perceived by the brain is proportional to the logarithm of the intensity received by the eye; - the sensitivity of the eye increases when the illumination decreases. The threshold Sd is thereby reduced
It follows that we can predict that a 90% reduction in intensity on one eye causes only a loss of 2 & 3% of the binocular visual sensation (dotted line CB ', Figure 5 b / plate II).

This results in the sensation of two images of unequal dimensions and non-overlapping profiles. This stereoscopic pseudo-couple gives an increased modeling to static objects.

It / OBJECTS IN RELATED MOVEMENTS
The asymmetry of the illuminations induces an asymmetry of the remanences whose consequence is a "shift" of the retinal images when the object is in motion
HELMOLTZ's experiments on the critical frequency of image fusion (cinema principle), show that the persistence of the retinal image decreases rapidly when the intensity decreases. Indeed, the light destroys the retinal purple and its biochemical reconstruction from erythropsin takes about 1/15 sec. for usual intensities and only a few 1/100 sec. for significantly lower intensities
The consequence is that, for a notable dissymmetry of intensity, the dark eye can easily be 2 times "faster" than the clear eye. Figure 6 (PLATE II) shows that, at the same time t = 0, the brain receives - coming from the clear eye, a merged image which integrates the instantaneous images 13, 14, 15, 16 with a decreasing memorization, symbolized in FIG. 6 a, by an increasing blackening; -from the dark eye, another merged image integrating only images 15 and 16 (FIG. 6 b).

We thus create, at the same instant, two groups of images, of clearly different sizes. It is also a stereoscopic pseudo-couple originating from an effect analogous to that which a line & delay would give, in electronics.
This feeling of relief increases with the speed of the relative movements of objects, of the camera or of the lighting system.
However, a good perception of the true relief created or recreated, implies the best possible definition of each image of the couple.

It will therefore be essential to have an optimal vision correction performed for relatively low intensities. Indeed, the dark eye works with the pupil wide open and aberrations can reduce the normally observable effects.

In addition, there is always an interest in eliminating stray light which adversely affects the contrast, therefore very directly in BR <the definition of the images indeed, it is recalled that the contrast is defined as the ratio of (I max.- I min. ) & I min. for an object whose clearest area emits I max. and the darkest area
I min. The denominator (I min.), Most often made up of stray light itself, plays the major role.

Figure 2 (PLATE I) effectively solves this problem
the central zone 6 of the dark glass is limited to an ellipse or a rectangle of height h of the order of 10 mm. and a length 1 of the order of 30 mm. Its transparency can vary from 1 & 20%
-peripheral zone 7 has a transparency of 0 & 5%
the central zone 4 of the clear glass can keep the same dimensions as those of 6 but the transparency is close to 100%; that of zone 5 can be reduced to 40%
In these conditions the contrast-field of vision compromise
is very satisfactory in many situations.

In case of slightly insufficient geometric correction, we
verified that the installation of a 3 & 5 mm diaphragm
diameter in front of the dark eye restores the effects of relief
without significant inconvenience on the spot. Indeed the eye
clear gives the brightness and details of the object in a
large field.

The basic realization of figure 1 (PLATE I) shows
the frame 3 which maintains the transparency lenses of 90
& 100% for 1 and about 1 & 20% for 2
Contact lenses would be more discreet
In all cases we will take large glasses
in the most enveloping frame 3 possible, with the
branches 0 as wide as possible to better limit the
side stray lights.

Figure 3 (PLATE I) shows the structure of a facade of
type of mask 8 for sports uses.
asymmetric absorbents 9 and 10 can use sup
photosensitive, anti-fog or polarizing ports
It is very pleasant to be able to adjust the absorption, in
particular in front of the dark eye, to adjust instantly
depending on taste or lighting conditions
the extent of the relief created.

your figure 4 (PLATE II) shows a simple realization
on the inner face of the glasses, two discs 10 and 11
with absorption and / or coloring sectors
different can revolve around off-center axes.

With discs whose edges, slightly notched, graze
the outer edge of the frame 3, the observer can, from
fingertip, adjust the extent of trans asymmetry
appearances on each eye. We can have games of dis
for different natural or special effects, inter
changeable.

We can, from a symmetrical transparency facade
80% (5 * fig. 4) obtained by gold or silver mirroring
on the outside of the lenses conceal the
variation of transparencies. With discs with a
totally transparent (or hollowed out) sector we can, on
the eye of your choice to achieve the necessary asymmetry.
will have the double advantage of being able to alternate clearly
dark eye and also have a symmetrical structure
that is to say ordinary glasses. The field is only
limited by a sector (4 *) with an area close to 90 mm2 on the dark side, in the relief vision.

Note: Experience shows that the relief effects.

increase with the dissymmetry of the absorptions but they disappear when the transparency, for the dark eye falls to 0.5%. By the eye. dark we still see the bright colored areas, which confirms the situation of daytime vision, but it seems that the brain is no longer able to operate the mixing of the impulses.

Claims (4)

1 / A series of glasses presenting, between the central areas of the two afocal lenses, transparency ratios to images of between 1/10 and 1/100 (ratios of transmission powers), each eye receiving an image NET of very different intensity but which may be of the same color 2 / A facade according to claim 1 in which the lenses are corrective 3 / A facade according to claims 1 and 2 in which the fields of vision, of asymmetrical transparencies are limited by opaque or transparent peripheral areas with very reduced images 4 / A facade according to claims 1, 2, 3 in which the clearest glass is completely transparent or even absent 5 / A facade according to claims 1,2,3 and 4 in which the field of vision is reduced by a window 3mm high by 5mm. in length, parallel to the horizontal axis of the facade, on one or both eyes 6 / A facade according to claims 2,3,5 with a disc & sectors for adjusting the transmission ratio, with one eye to the other, in the interval from 1/10 to 1/100 with colors identical or not for each eye thanks to the use of a second disc in front of the other eye. 7 / A facade according to claim 6 in which the ratio of transmission powers can take the value 1 by using totally transparent or hollowed out sectors. 8 / Contact lenses according to claims 1,2 and 4 9 / A front panel according to claims 1,2,3,4,5 and 7 which can be clipped onto any frame. 10 / A facade according to claims 1,2,3,4,5,7 and 9 with an external "mirror" coating to mask the asymmetry