EP3990979A1 - Spiral dioptre with meridians of different optical power - Google Patents

Abstract

The invention concerns an optical device (100, 200, 400, 800) having an optical axis, comprising at least one surface with at least two meridians, of which at least one part forms, in front view, at least one spiral portion, the central point (206, 406, 806) of which is on the optical axis, each spiral portion defining meridians of different optical powers, in order that the focusing obtained extends over a tubular region.

Description

Description

Title: Spiral dioptre with meridians of different optical powers.

Technical area

The present invention relates to the field of optical devices forming diopters.

Although described with reference to an ophthalmic lens application, the invention applies to any diopter, spherical or toric, and to any diopter with a surface with at least two meridians, which can be used for image formation. and / or optical power distribution and / vision correction.

Thus, an optical device according to the invention may be an optical lens of an optical system, a spectacle lens or a rigid or flexible contact lens, part of a photographic lens, part of a motion detector, a device for concentrating light energy.

In general, the invention applies to any application where a focusing of light is implemented, in the visible or invisible domain.

Prior art

A lens, for example an ophthalmic lens, comprises two opposing optical surfaces called diopters, connected by a wafer generally inscribed in a cylinder with a circular base.

To date, there are four distinct categories of optical surfaces in particular, namely:

- spherical diopters, the surface of which is part of the internal or external surface of a sphere;

- aspheric diopters, derived from spherical surfaces; the surface of which is part of a surface of revolution whose curvature varies continuously from the top to the periphery;

- toric diopters whose surface has two orthogonal main meridians of unequal curvature and whose cross section along these two meridians is nominally circular;

- Atoric dioptres whose surface has two main meridians mutually perpendicular of unequal curvature and whose cross section of at least one of the main meridians is not circular. The focusing of a spherical lens formed by the association of two spherical diopters has a single focal length, at a point called the image focal point. This one-point focusing is characteristic of a so-called “stigmatic” optical system.

With reference to Figure 1, we recall here the well-known principle of astigmatism (absence of stigmatism at a single point as for a spherical lens) produced by an optical lens having a toric surface 1.

The toric surface 1 has a first meridian 2 curved with a first curvature C1 around an axis of revolution of a torus not shown in the figure, so that the first meridian 2 forms an arc of a circle carried by a first defined circle by an outer radius of the torus.

The toric surface 1 also has a second meridian 3 perpendicular to the first meridian 1 and curved with a second curvature C2 greater than the first curvature around a center of curvature located on the radius of the torus which passes through the middle of the first meridian 2, designated as A- A. The axis A- A constitutes the optical axis of the toric surface.

The lens is formed from an optical material of refractive index n, so that light passing through said toric surface 1 is refractive.

In particular, under parallel lighting, the light crossing the first meridian 2 converges at a first focal length 4 forming a segment 5 parallel to the first meridian 2 and the light crossing the second meridian 3 converges at a second focal distance 6 forming a segment 7 parallel to the second meridian 3.

The toric lens 1 has two dioptric powers DI and D2 provided by the following relationships: DI = (n-l) Cl and D2 = (n-l) C2.

US-A-5198844 discloses a multifocal lens divided into a plurality of alternating segments which have at least two different refractive powers. In one embodiment, the boundaries between successive segments are arcs starting from the center of the lens. This lens has only spherical or aspherical segments, these segments also having surface junctions in the form of ridges.

In general, there is a need to improve optical devices with so-called stigmatic spherical surfaces, in order to lengthen their zone of focus.

An aim of the invention is to respond at least in part to this need. Disclosure of the invention

To do this, the invention relates in one aspect to an optical device having an optical axis, comprising at least one surface with at least two meridians, of which at least a part forms, in front view, at least one portion of a spiral of which the central point is on the optical axis, each portion of the spiral defining meridians of different optical powers, so that the focus is no longer simply stigmatic at one point, but extended over a tubular zone which stretches on the optical axis .

By "front view" is meant here and in the context of the invention, a view of the device along the optical axis. Otherwise expressed, it is a projection view in a plane orthogonal to the optical axis.

For clarity, the spiral-shaped surface portion is defined as a projection in a plane orthogonal to the optical axis. Since a portion of a spiral according to the invention is developed on a three-dimensional surface, it is called a helix.

Thus, the invention essentially consists in generating from a surface with two or more meridians of one diopter, a surface with at least one helix portion, that is to say a spiral surface in projected view. in a plane orthogonal to the optical axis.

In other words, the invention essentially consists in making a dioptre having a spiralization of a surface with two meridians.

In a way, if the surface with two or more meridians were in a malleable state, one would realize a deformation by torsion of this surface according to one or more spiral curves.

This spiralization can be applied to all non-spherical diopter surfaces, which have more than two meridians.

The spiralization is preferably carried out from a toric surface, and more preferably from an optical device with two concentric tori having meridians in opposition, i.e. at 90 ° to each other.

In the case of a toric surface, this allows a distribution of light by the curvature of the first meridian at a first focal distance and a distribution of light by the curvature of the second meridian at a second focal distance, while the spiraling of the axes of astigmatism has the effect of creating a spiral focusing tube of light and thus lengthening the focal length of the diopter.

A portion of a spiral according to the invention can have different shapes, for example according to a linear law, a quadratic law or a substantially logarithmic law. These different laws can also be combined on the same surface of an optical device, for example for a lens with a logarithmic law on a first annular portion of the lens and a quadratic or linear law on a second annular portion of the lens surrounding the first portion annular.

A portion of a spiral according to the invention can be created on only part of a diopter. It can thus be carried out only in a central part, in a junction part between two distinct surfaces, for example two toric surfaces, in a peripheral part.

The tubular focus obtained according to the invention results in a homogeneous focus over an elongated range of focal lengths, which fits into a tube.

The advantages of the invention are numerous, among which we can mention:

- the possibility of reducing the focus settings in any optical imaging system, such as a photographic lens, a camera, a projector lens, a virtual reality headset, etc. ;

- the possibility of reducing the size of an optical imaging system, for example by eliminating the currently existing motorized focusing devices;

- implementation in optical power concentration systems such as solar heating systems or laser cutting devices. For example, in a laser cutting device, the tubular focusing can increase the length of the zone of focus along the optical axis and thus increase the thicknesses that can be cut;

- operation in optical detection systems, such as infrared motion detectors or physical measurement systems, with the advantage of reducing focus settings, thanks to the length of the resulting sharpness zone tubular focusing; - in vision correction applications, tubular focusing enables an area of sharpness to be generated over a long range of focal lengths, for example so as to ensure near and far vision and to allow optical compensation of the presbyopia, as well as several ametropia with a single ophthalmic lens. An ophthalmic lens can thus be used for more than a single ametropia value. Tubular focusing also makes it possible to improve the focusing of the rays out of the optical axis to improve the field of vision. This can especially be put to good use in ophthalmic lenses. An optical lens, one surface of which has been generated by the spiraling according to the invention makes it possible in particular to lengthen the caustic of the focal lengths.

In general, an optical device embodying the invention can be used in any image forming application, for example photography, video, optical detection, for vision correction, and in any other application requiring a focus.

An optical device, in particular a lens, can be made from any optical material such as optical glass or a polymer.

The spiral portion (s) according to the invention can be produced by machining, additive manufacturing or molding techniques, alone or in combination with one another.

According to an advantageous embodiment, the spiral portion (s) is (are) generated from a toric surface having a first meridian curved along a first non-zero curvature and a second meridian curved along a second curvature strictly greater than the first curvature, the second meridian being perpendicular to the first meridian.

According to this embodiment and an advantageous variant embodiment, the spiral portion (s) is (are) generated from a first and a second toric surface, the first toric surface having a first meridian curved along a first non-zero curvature around an axis of revolution of a first torus and a second meridian curved along a second curvature strictly greater than the first curvature, the second meridian being perpendicular to the first meridian, the second surface toric having a first meridian curved along a first non-zero curvature around an axis of revolution of a second torus and a second meridian curved with a strictly second curvature greater than the first curvature and perpendicular to the first meridian of the second toric surface, the first and second toric surfaces each comprising a plurality of azimuthal angular sectors disposed around the optical axis, the first meridian of the first toric surface and the first meridian of the second toric surface have azimuthal orientations separated by a non-zero angle around the optical axis, the spiral portions defining first and second optical power meridians resulting from the first meridian of the first toric surface and from the first meridian of the second toric surface.

According to an alternative embodiment, an azimuthal angular sector of the first toric surface and an azimuthal angular sector of the second toric surface are adjacent by a border in a portion of a spiral.

The first and second toric surfaces can each comprise two diametrically opposed azimuthal angular sectors.

Each angular sector of the first toric surface may be adjacent to the two angular sectors of the second toric surface.

According to an advantageous characteristic, the angle between the azimuthal orientations of the first meridian of the first toric surface and the first meridian of the second toric surface is between 60 ° and 90 °.

Preferably, the first curvature of the first toric surface is equal to the first curvature of the second toric surface.

More preferably, the second curvature of the first toric surface is equal to the second curvature of the second toric surface.

According to an alternative embodiment, in polar coordinates, the radius of a portion of a spiral is linked to the angle of the spiral by a linear law, a quadratic law or a logarithmic law.

According to another embodiment, the optical device further comprises a spherical surface centered on the optical axis. The optical device according to the invention can advantageously constitute an optical lens, the front face of which is the surface with at least one portion of a spiral.

Another subject of the invention is the use of an optical device which has just been described, for correcting vision and / or concentrating light power and / or forming an image.

Brief description of the drawings

Other advantages and characteristics of the invention will emerge better on reading the detailed description of examples of implementation of the invention given by way of illustration and not by way of limitation with reference to the following figures, among which:

- Figure 1 is a schematic representation of the distribution of a parallel beam of light having passed through an optical lens with a toric surface;

- Figure 2 is a schematic front view of a first embodiment of the tubular focusing optical lens;

- Figure 3 is a schematic front view of a multifocal optical lens with two toric surfaces in axis opposition;

- Figure 4 is a schematic perspective view of the multifocal optical lens of Figure 3;

- Figure 5 is a schematic view of the distribution of a parallel beam of light having passed through the optical lens of Figures 3 and 4;

- Figure 6 is a schematic front view of one embodiment of a multifocal optical lens with two toric surfaces in axis opposition;

- Figure 7 is a schematic front view of one embodiment of the tubular focusing lens according to the invention generated from the geometry of the lens of Figure 6;

- Figure 8 is a schematic front view of another embodiment of a multifocal optical lens with two toric surfaces in axis opposition;

- Figure 9 is a schematic front view of another embodiment of the tubular focusing lens according to the invention generated from the geometry of the lens of Figure 8;

FIG. 10 is a schematic side view of the distribution of a parallel light beam having passed through an optical lens according to the invention and by comparison a spherical optical lens according to the state of the art; FIG. 11 is a schematic perspective view of a beam of parallel light rays having passed through an optical lens according to the invention with logarithmic spirals, FIG. 11 showing the tubular zone of focusing of the light ray;

FIG. 12 is an enlarged view of the focusing tube of the light ray beam of FIG. 11 and by comparison of the focusing zone of a lens with toric surfaces in opposition to the axis as illustrated in FIG. 6.

- Figure 13 is a front view of an alternative embodiment of a tubular focusing lens according to the invention comprising a spherical central part and a spiral peripheral part;

- Figure 14 is a front view of another variant embodiment of a tubular focusing lens according to the invention comprising two toric surfaces and a junction part between them which is spiral.

detailed description

Figure 1 relating to the state of the art has already been commented on in the preamble. It is therefore not detailed below.

The following figures show several examples of optical lenses according to the invention, having surfaces with more than two meridians with at least one spiral portion generating a focus which extends over a tubular zone.

As emerges from the various figures, a portion of spiralization can be produced in different ways, for example according to a linear law, a quadratic law or a substantially logarithmic law. These different laws can also be combined on the same lens, for example with a logarithmic law on a first annular portion of the lens and a quadratic or linear law on a second annular portion of the lens surrounding the first annular portion.

The same optical device can comprise several portions of spirals.

FIG. 2 shows a tubular focusing optical lens 800 according to a first embodiment of the invention. The representation used indicates by contrast the distance perpendicular to the plane of the figure: darker means further from the reader and lighter means closer to the reader. The optical lens 800 is generated by spiraling from a toric surface of the lens as shown in Figure 1. The center point 806. Thus, the geometry of the surface 801 has a spiral whose center point 806 is on. the optical axis. In polar coordinates, the angle of the spiral increases as we move radially away from the optical axis. In particular, the first meridian 802 having the first curvature additionally has a spiral shape around the optical axis. In addition, lines 803 which have the second curvature and which would appear parallel to the second meridian in the toric lens of FIG. 1 here present different azimuthal orientations as one moves away from the optical axis, due to the spiralization .

In fact to achieve the invention, after analyzing the shortcomings of multifocal lenses according to the state of the art, the inventor sought to stretch the zone of focus on the optical axis.

Starting from multifocal lenses with two concentric toric surfaces, he then thought of putting them in axis opposition.

Figures 3 and 4 show a front and perspective view of such a multifocal optical lens 100. The multifocal optical lens 100 includes a first toric surface 102 and a second toric surface 104 surrounding the first surface 102 concentrically.

Thus, in an axial view of the lens 100 along the optical axis A-A, the first surface 102 corresponds to a first optical zone and the second surface 104 corresponds to a second optical zone concentric to the first surface 102.

The first toric surface 102 has a first meridian 102i curved along a first curvature and a second meridian 102 ₂ curved along a second curvature and perpendicular to the first meridian 102i. Likewise, the second surface 104 has a first meridian 104i curved along a first curvature and a second meridian 1042 curved along a second curvature and perpendicular to the first meridian 104i. In particular, in each of the first and second surfaces 102, 104, the second curvature is greater than the first curvature.

The periphery of each of the first and second surfaces 102, 104 is a circular section.

The first meridian 102i of the first surface 102 is perpendicular to the first meridian 104i of the first surface 104. The first curvature of the first surface 102 may be different or equal to the first curvature of the second surface 104. Likewise, the second curvature of the first surface 102 may be different or equal to the second curvature of the second surface 104.

Thus, the lens 100 comprises two concentric tori having different meridian axes, in particular in counter-axis or in opposition, that is to say forming an angle of 90 ° between the two tori.

FIG. 5 illustrates the distribution of light having passed through the multifocal optical lens 100 under parallel illumination in an example where the first curvature of the first surface is equal to the first curvature of the second surface and where the second curvature of the first surface is equal to the second curvature of the second surface. Light passing through first meridian 102i of first surface 102 converges at a first focal length 106 forming a first segment 1081 parallel to first meridian 1021 and light crossing second meridian 1022 of first surface 102 converges at second focal length 110 forming a second segment 1082 parallel to the second meridian 1022.

In addition, the light passing through the first meridian 104i of the second surface 104 converges at the level of the first focal length 106 forming a first segment 112i parallel to the first meridian 104i and the light crossing the second meridian 104 ₂ of the second surface 104 converges at the second focal length 110 by forming a second segment 112 ₂ parallel to the second meridian 104 ₂ .

Thus, with such a lens 100, an elongation of the focusing zone is obtained compared to those of multifocal lenses according to the state of the art. This elongated focusing zone is dependent on the toricity of the surfaces 102, 104.

Noting that this zone of focusing was not sufficiently concentrated, the inventor then thought of carrying out the spiralization of the surfaces, in order to obtain a focusing which is concentrated in a tubular zone and thus to have the possibility of a focus over a longer distance on the optical axis.

FIGS. 6 and 7 illustrate an embodiment of a tubular focusing optical lens 200 with a double toric surface respectively with axis opposition and spiral from the latter. The optical lens 200 of FIG. 6 comprises a first toric surface 202 having a first meridian 202i curved along a first curvature about an axis of revolution of a first torus and a second meridian, represented by an arc 202 ₂ parallel to the second meridian, curved along a second curvature greater than the first curvature and perpendicular to the first meridian 202 ₁ . The optical lens 200 also comprises a second toric surface 204 juxtaposed with the first toric surface 202 and having a first meridian 204i curved along a first curvature about an axis of revolution of a second torus and a second meridian, represented by an arc 204 ₂ parallel to the second meridian, curved along a second curvature and perpendicular to the first meridian 2041. In front view, that is to say in projection in a projection plane perpendicular to an optical axis of the lens 200 passing through its center 206, the first toric surface 202 corresponds to two azimuthal angular sectors 208 ₂ and 208 ₄ diametrically opposed and meeting at their vertices which are turned towards the center 206 of the optical lens 200. Likewise, the second surface toric 204 corresponds to two azimuthal angular sectors 208 ₁ and 2O8 ₃ diametrically opposed and meeting at their vertices which are turned towards the center 206. Each azimuthal angular sector 208 ₂ and 208 ₄ of the first toric surface 202 is adjacent to the two azimuthal angular sectors 208i and 208 ₃ of the second toric surface 204. The angular sectors 208 are delimited by the intersections of the first toric surface 202 and the second toric surface 204, which are lines of intersection in space between two rings with cylindrical sections whose axes of revolution are perpendicular. These intersection lines are represented by the borders 210i, 2IO ₂ , 2IO ₃ and 210 ₄ between the azimuthal angular sectors 208i, 2O8 ₂ , 2O8 ₃ and 208 ₄ . In space, each of the boundaries 210i, 2IO ₂ , 2IO ₃ and 210 ₄ is arranged recessed in the direction of the optical axis with respect to the prime meridians 2021 and 2041.

FIG. 7 shows an optical lens 200 generated by a spiralization of the toric lens surfaces according to FIG. 6. Thus, the first meridian 202 ₁ of the first toric surface 202 and the first meridian 204 ₁ of the second toric surface 204 is a portion spiral whose center point 206 is on the optical axis of the optical lens 200. Similarly, each of the borders 210i, 2IO ₂ , 2IO ₃ and 210 ₄ is a portion of a spiral whose center point 206 is on the axis optics of the optical lens 200. Spiralization can be carried out in different ways, for example according to a linear law, a quadratic law or a substantially logarithmic law. For the application of a logarithmic law, a simplification must be made near the center 206 of the lens, where the spiral angle would be mathematically divergent.

In the example shown in FIG. 7, the increasing angle reaches 45 ° at the periphery of the optical lens 200. This angle could have another value, for example between 30 ° and 720 °, in particular equal to 60 °. . The periphery 25 of the optical lens 200 here has a circular shape. This shape can be other than circular.

FIGS. 8 and 9 illustrate an embodiment of a tubular focusing optical lens 400 with a double toric surface respectively in axis opposition and spiraling from the latter.

The tubular focusing optical lens 400 of Figure 8 is designed similarly to the optical lens 200 of Figure 6, but with three distinct azimuthal sectors 401, 402, and 403 instead of four azimuthal sectors. Each azimuthal sector 401, 402, 403 has a toric surface portion, with respective prime meridians 4011, 4021, 4031 which are oriented in different azimuthal directions, at 120 ° from each other in the symmetrical case such as represented. The second meridians are not shown here and are each time perpendicular to the respective first meridians. The azimuthal sectors 401, 402, 403 are delimited by borders 405.

Figure 9 illustrates a tubular focusing lens 400 generated from the lens surface according to Figure 8. Here, the spiral portions follow a quadratic spiral law: the spiral angle is proportional to the square of the radial distance by relative to the center 406 on the optical axis. Each of the boundaries 405 and each of the prime meridians 4011, 4021, 403i has the same spiral geometry. In the example shown, the spiral angle reaches 360 ° at the periphery of the optical lens 400, or one full revolution. A second full turn could be made for a larger lens size, i.e. an angle of 720 ° or more.

By way of numerical example, a tubular focusing optical lens 400 of FIG. 9 was implemented with a front face with four identical toric branches, the parameters of which are as follows:

- first curvature of the toric surface: focal length equal to 17.4 cm - second curvature of the toric surface: focal length equal to 14 cm

- the focuses are spaced 1.4 diopters

- shape of the spiral: logarithmic to the golden ratio

- spiral angle: 720 °

- lens diameter: 10 mm

- other geometric parameters: the rear face is spherical with a radius of curvature of 7.8mm. The thickness at the center of lens 400 is 0.5mm.

In general, a tubular focusing optical lens according to the invention can be designed similarly to one of the optical lenses 200, 400, 800 shown from any number of toric surfaces each occupying an azimuthal angular sector. Thus, the number of toric branches distributed around the optical axis in the spiral surface can be even (for example 2 branches in the optical lens 800, 4 branches in the optical lens 200) or odd (for example 3 branches in the lens optical 400). Other numbers of branches are possible, for example 5, 6, 7 or more.

On the other hand, the boundaries between the adjacent toric surfaces can be either straight boundaries or smooth boundaries. For example, the local curvature can be interpolated around the boundaries to provide smooth transition zones between adjacent toric surfaces and thus limit extreme slopes.

The tubular focusing obtained according to the invention is shown in FIG. 10 by comparison between a spherical optical lens 1301 according to the state of the art and a tubular focusing optical lens according to the invention 1302, each of these two lenses 1301, 1302 being designed for vision correction. In this FIG. 10, parallel illumination is incident on the lenses 1301 and 1302, Z designating a zone of sharpness perceived by the human eye which extends on either side of the focal point of the lenses. As emerges very clearly from this FIG. 10, the spiral lens 1302 makes it possible to obtain an elongation of the zone of sharpness Z delimited by an imaginary right cylinder. Thus, the spiraling of the different optical powers makes it possible to obtain a tubular focusing of the light rays. In other words, if one of the two diopters is replaced in a spherical lens 1301 according to the state of the art by the spiral toric surface 1302 according to the present invention, this has the effect of lengthening the focus area. The stigmatism zone is then no longer a point, but a focusing tube.

The inventor performed an optical ray tracing calculation under parallel illumination. FIG. 11 shows a lens 400 like that of FIG. 9, on the object focus side. The focus area XV is shown enlarged in the upper part of Figure 12.

FIG. 12 also shows the focal distances DI and D2 corresponding respectively to the first curvature and to the second curvature of the initial toric surface. On the right of Figure 12, line 1501 shows the size of the focus task at DI and line 1502 shows the size of the focus task at D2.

By comparison, the lower part of figure 12 shows the same elements for an astigmatic lens in opposition of axis as according to figure 6, having the same curvatures as the initial ones of figure 11: line 1511 shows the size of the task focus at DI and line 1512 shows the size of the focus task at D2.

It is clear from this figure 12, that the spiraling of a lens according to the invention has the effect of tightening the focusing task between DI and D2 substantially in the form of an imaginary right cylinder.

Other variations and advantages of the invention can be realized without departing from the scope of the invention.

If in the examples illustrated, the spiral portions are produced over the entire optical surface of the lens, it is possible to envisage performing the spiralization only over a part.

FIG. 13 thus illustrates a variant according to which the optical lens 300 comprises a spherical surface 302 arranged at the center of the optical surface of the lens 300, the spiral portions being produced only on the periphery of the optical surface.

FIG. 14 illustrates a variant according to which an optical lens 100 with two toric surfaces 102, 104 concentric with a junction part 114 spiraled according to the invention. The invention is not limited to the examples which have just been described; characteristics of the examples illustrated can in particular be combined with each other within variants not illustrated.

Claims

Claims 1. Optical device (100, 200, 400, 800) having an optical axis, comprising at least one surface with at least two meridians, of which at least a part forms, in front view, at least a portion of a spiral whose point central (206, 406, 806) is on the optical axis, each spiral portion defining meridians of different optical powers, so that the focus obtained extends over a tubular zone. 2. Optical device according to claim 1, the portion (s) of the spiral (s) being generated from a toric surface having a first meridian curved along a first non-zero curvature and a second meridian ( 202 ₂ , 803) curved along a second curvature strictly greater than the first curvature, the second meridian being perpendicular to the first meridian. 3. Optical device according to claim 2, the portion (s) of the spiral (s) being generated from a first and a second toric surfaces, the first toric surface (208 ₂ , 401 ) having a first meridian (2021, 4011) curved along a first non-zero curvature around an axis of revolution of a first torus and a second meridian (2022) curved along a second curvature strictly greater than the first curvature, the second meridian being perpendicular to the first meridian, the second toric surface (2081, 402) having a first meridian (2041, 4021) curved according to a first non-zero curvature around an axis of revolution of a second torus and a second meridian (204 ₂ ) curved with a second curvature strictly greater than the first curvature and perpendicular to the first meridian (2041) of the second toric surface, the first and second toric surfaces each comprising a plurality of azimuthal angular sectors arranged around e optical axis, the first meridian (2021, 4011) of the first toric surface (208 ₂ , 401) and the first meridian (2041, 4021) of the second toric surface (2081, 402) have azimuthal orientations separated by a non-zero angle around the optical axis, the spiral portions defining first and second optical power meridians (2021, 4011; 2041, 4021) resulting from the first meridian (208 ₂ , 401) of the first toric surface and from the first meridian (2081, 402) of the second toric surface. 4. Optical device (200, 400) according to claim 3, an azimuthal angular sector (2O8 ₂ ) of the first toric surface and an azimuthal angular sector of the second toric surface (2081) being adjacent by a border (210) in portion spiral. 5. Optical device (200) according to claim 3 or 4, the first (208 ₂ , 2O8 ₄ ) and second (208 ₁ , 208 ₃ ) toroidal surfaces each comprising two diametrically opposed azimuthal angular sectors. 6. Optical device (200) according to claim 5, each angular sector of the first toric surface (208 ₂ , 208 ₄ ) being adjacent to the two angular sectors of the second toric surface (208 ₁ , 208 ₃ ). 7. Optical device (200, 400) according to any one of claims 3 to 6, the angle between the azimuthal orientations of the first meridian of the first toric surface (208 ₂ , 401) and the first meridian of the second toric surface (208 ₁ , 402) is between 60 ° and 90 °. 8. An optical device (200, 400) according to any one of claims 3 to 7, wherein the first curvature of the first toric surface (208 ₂ , 401) is equal to the first curvature of the second toric surface (208 _1). , 402). 9. An optical device according to any one of claims 3 to 8, wherein the second curvature of the first toric surface (208 ₂ , 401) is equal to the second curvature of the second toric surface (208 ₁ , 402). 10. Optical device (200, 400, 800) according to one of the preceding claims, in polar coordinates, the radius of a portion of a spiral being related to the angle of the spiral by a linear law, a quadratic law or a law. logarithmic. 11. Optical device according to one of the preceding claims, further comprising a spherical surface (302) centered on the optical axis. 12. Optical device (200, 400, 800) according to one of the preceding claims, constituting an optical lens whose front face is the surface with at least one spiral portion. 13. Use of an optical device (200, 400, 800) according to one of the preceding claims, for correcting vision and / or concentrating light power and / or forming an image.