阅读说明：本技术 用于钟表的光学装置 (Optical device for a timepiece ) 是由 阿德里安·卡特利纳 伯努瓦·朱诺 塞巴斯蒂安·佩瑟盖尔 于 2019-05-30 设计创作，主要内容包括：一种钟表镜片、特别是手表镜片,其中其包括具有用于放大由钟表提供的标记的至少一个透镜的光学装置,该透镜包括至少一个非球面表面,其具有穿过包含垂直方向z的光轴的垂直平面的至少一个截面,该截面的至少一条轮廓线可以由下述等式限定：<Image he="137" wi="700" file="DDA0002078860460000011.GIF" imgContent="drawing" imgFormat="GIF" orientation="portrait" inline="no"></Image>其中R是标称曲率半径,k是锥度常数,并且α<Sub>(4,6,……)</Sub>是非球面系数,并且其中至少锥度常数k和/或至少一个非球面系数不等于0。(A timepiece lens, in particular a watch lens, wherein it comprises an optical device having at least one lens for magnifying indicia provided by a timepiece, the lens comprising at least one aspherical surface having at least one section through a vertical plane containing an optical axis of a vertical direction z, at least one contour of the section being definable by the equation wherein R is a nominal radius of curvature, k is a taper constant and α (4,6,……) is an aspherical coefficient, and wherein at least the taper constant k and/or the at least one aspherical coefficient is not equal to 0.)

1. An eyeglass for a timepiece, in particular a wristwatch, wherein the eyeglass comprises an optical device comprising at least one lens for magnifying a mark provided by the timepiece, the lens comprising at least one aspherical surface comprising at least one section through a vertical plane containing an optical axis of a vertical direction z, at least one contour of the section being definable by the following equation:

wherein R is the nominal radius of curvature, k is the taper constant, and α_{(4，6，……)}Is a non-spherical surface coefficient of the spherical surface,

And wherein at least the taper constant k and/or at least one aspheric coefficient is not equal to zero.

2. The eyeglass of a timepiece according to claim 1, wherein at least one lens comprises at least one outer casing enclosing it, the outer casing being made entirely of a rigid material that is not deformable, or wherein at least one lens is made entirely of a rigid material that is not deformable, and/or wherein the at least one lens is made of a hard crystal material.

3. The eyeglass of any preceding claim, wherein at least one lens comprises at least one aspheric convex surface.

4. The lens of a timepiece according to any one of the preceding claims, wherein at least one aspherical surface includes or does not include rotational symmetry about a vertical axis.

5. The lens for a timepiece according to any one of the preceding claims, wherein the at least one aspherical surface comprises a section through a vertical plane, at least one contour line of which comprises a portion of a circle and an inflection point, thereby causing a change in concavity or convexity.

6. The eyeglass of any preceding claim, comprising a single lens with at least one aspherical surface, or two lenses, a first lens with at least one aspherical surface and a second lens with or without at least one aspherical surface.

7. The eyeglass of any preceding claim, wherein the eyeglass comprises a lens having at least one aspheric surface and formed or added on a top or bottom surface of the eyeglass, the lens being made of the same or a different material than the eyeglass, or wherein the eyeglass comprises a lens having at least one aspheric surface and formed directly in the thickness of the eyeglass.

8. The lens of a timepiece according to any one of the preceding claims, wherein the lens includes: a first lens having at least one aspherical surface and disposed on a bottom surface of the optic; and a second lens having at least one aspherical surface or a surface that is not aspherical and disposed to be superposed on the first lens on a top surface of the optic.

9. The ophthalmic lens of a timepiece according to any one of the preceding claims, wherein the ophthalmic lens comprises a lens having at least one aspherical surface and a cross section through a plane parallel to the surface of the ophthalmic lens, the cross section being substantially circular or substantially elliptical.

10. The ophthalmic lens of a timepiece according to any one of the preceding claims, wherein the ophthalmic lens includes a lens having at least one aspherical surface and made of the same or a different material than the ophthalmic lens.

11. Timepiece, in particular wristwatch, wherein it comprises a lens according to any one of the preceding claims.

12. Timepiece according to claim 11, wherein the timepiece comprises at least one indicator selected from an hour indicator, a display of hours or minutes, a calendar indicator, for example an indicator of the day of the month, the date, the month or the phase of the month, and/or an indicator comprising any annotation or any pattern, for example at least one number, at least one letter and/or at least one colour, and wherein the timepiece comprises at least one lens having at least one aspherical surface of the lens and disposed above the indicator.

13. Timepiece according to claim 11 or 12, wherein the timepiece comprises a mobile indicator arranged for displaying a specific mark in a window of a dial of the timepiece, and wherein the timepiece comprises at least one lens having at least one aspherical surface of the lens of any one of claims 1 to 10 and arranged above the window of the dial, so as to optimize the visibility of the specific mark appearing in the window.

14. Timepiece according to claim 12 or 13, wherein the timepiece comprises an indicator arranged in a plane parallel to the mirror plate, the mirror plate comprising at least one lens having at least one aspherical surface, the at least one lens having at least one aspherical surface occupying a surface area less than or equal to 30% of the total surface area of the top surface of the mirror plate, or less than or equal to 20% of the total surface area, or less than or equal to 10% of the total surface area, and/or the at least one lens having at least one aspherical surface being superposed in a direction substantially perpendicular to at least one indicator to be magnified of the timepiece, and/or the at least one lens having at least one aspherical surface being fixed with respect to the mirror plate.

15. The timepiece according to any one of claims 12 to 14, wherein the lens forms a tight housing for the at least one indicator and comprises at least one lens having at least one aspherical surface and being superposed on the at least one indicator.

Technical Field

The invention relates to an optical device for a timepiece. The invention also relates to a timepiece lens comprising such an optical device. Finally, the invention also relates to a timepiece comprising such an optical device.

Background

A conventional solution for optimizing the visibility and improving the legibility of the marks on a timepiece consists in incorporating on the timepiece a lens that magnifies the mark to be read. However, it appears that the existing solutions enable an optimized reading perpendicular to the lens, but are less efficient when the wearer of the timepiece is offset with respect to the timepiece and therefore with respect to the lens. In practice, it has been found that for a given lens and indicator of a timepiece mark, a simple offset of more than about 10 ° no longer achieves the benefit of advantageously reading the timepiece mark through the lens, even outside the lens. Thus, due to this use limitation, this conventional scheme is in fact optimizable.

A general object of the present invention is to provide a solution for improving the reading of indicia on a timepiece that does not comprise all or some of the drawbacks of the prior art.

More specifically, a first object of the invention is to provide a user-friendly solution for reading indicia on a timepiece. In particular, it is a general object of the present invention to provide a magnified reading of indicia visible over a larger angular range than in the prior art.

Disclosure of Invention

To this end, the invention is based on an ophthalmic lens for a timepiece, in particular a wristwatch, wherein the ophthalmic lens comprises at least one lens comprising at least one aspherical surface comprising at least one section through a vertical plane containing the optical axis of the vertical direction z, at least one contour of the section being defined by the following equation:

Wherein R is the nominal radius of curvature, k is the taper constant, and α_{(4，6，……)}Is an aspheric coefficient, and wherein at least the taper constant k and/or at least one aspheric coefficient is not equal to zero.

The at least one lens may comprise at least one outer shell surrounding the at least one lens, the outer shell being made entirely of a non-deformable rigid material, or the at least one lens may be made entirely of a non-deformable rigid material, and/or the at least one lens may be formed of a rigid crystalline material.

The invention also relates to a timepiece comprising such a lens.

the invention is more particularly defined by the claims.

Drawings

These objects, features and advantages of the present invention will be explained in detail in the following description of a particular embodiment thereof, given as a non-limiting example, with reference to the accompanying drawings, in which:

Fig. 1 shows a reference positioning of an observer with respect to a timepiece according to an embodiment of the invention.

Fig. 2 shows an offset positioning of an observer relative to a timepiece according to an embodiment of the invention.

Fig. 3 shows the range of viewing angles of a timepiece according to an embodiment of the invention.

Fig. 4 shows a section through the median vertical plane of the optical means of the lens of a timepiece according to a first variant of the first embodiment of the invention.

fig. 5 shows a section through the median vertical plane of the optical means of the lens of a timepiece according to a second variant of the first embodiment of the invention.

Fig. 6 shows a section through the median vertical plane of the optical means of the lens of a timepiece according to a third variant of the first embodiment of the invention.

fig. 7 shows a section through the median vertical plane of the optical device of a timepiece lens according to a fourth variant of the first embodiment of the invention.

Fig. 8 shows a section through the median vertical plane of the optical means of the lens of a timepiece according to a first variant of the second embodiment of the invention.

Fig. 9 shows a section through the median vertical plane of the optical means of the lens of a timepiece according to a second variant of the second embodiment of the invention.

Fig. 10 shows the geometry of an optical device for a timepiece according to an embodiment of the invention.

Detailed Description

Fig. 1 shows a timepiece 1 according to an embodiment of the invention, comprising at least one indicator 2, for example arranged on a dial. The timepiece comprises, on its top surface, an optical device 10, which is arranged substantially above the indicator 2. The timepiece, and in particular the top surface thereof, extends substantially in a plane P which is conventionally considered to define a horizontal plane.

For the sake of simplicity of the following description, the direction at right angles to the horizontal plane P of the timepiece will denote the vertical direction z. Fig. 1 shows a reference position of an observer O who observes a timepiece, in particular, the pointer 2, from a position located on a vertical axis passing through the center of the pointer 2. More specifically, a vector v connecting the indicator with the eye of the observer is oriented along the vertical direction z. This reference position of the observer is generally a position that allows it to have the best legibility of the pointer 2.

In addition, the adjective "top" is defined to mean the part or surface of the timepiece oriented on the side of the observer O of the timepiece. In contrast, the adjective "bottom" denotes a component or surface of the timepiece oriented on the side opposite to the observer of the timepiece (for example, on the side of the wearer's wrist in the case of a wristwatch).

fig. 2 shows an alternative offset positioning of the observer O with respect to the reference position defined by fig. 1, with respect to the timepiece 1. This offset is measured by the angle theta between the above-mentioned perpendicular direction z and the vector v. Note that the observer may be offset in a first direction located on a specific side with respect to the vertical direction z, or may be offset in an opposite second direction with respect to the same vertical direction. In these two directions, the two angles θ min and θ max shown in fig. 3, respectively, can be empirically obtained by the observer, the additional offset beyond these two angles no longer allowing the observer to observe the indicator 2 of the timepiece.

Note that these two offsets are preferably obtained by the displacement of the observer's gaze in the same plane P', which may be a vertical plane passing through the indicator 2 and substantially parallel to the direction extending from the 6 and 12 hour marks of the timepiece according to the traditional method of positioning hour marks. Of course, the same kind of offset can be achieved along a vertical plane in all other directions, so that finally a cone of vertical axes centered on the indicator can be substantially determined, within which cone the legibility of the indicator is good. Such cones may have an elliptical bottom surface, defining a minimum angle and a maximum angle with respect to the above-mentioned perpendicular direction, so that they may define two angles θ min and θ max in a variant.

As mentioned in the technical field of the present invention, the technical problem posed is therefore that of optimizing the two angles θ min and θ max, that is to say of increasing the size of the good legibility or visibility range. In other words, the present invention seeks to obtain good legibility or visibility of the pointer 2 by increased offset positioning of the observer.

According to the concept of the invention, an optical device is used, which comprises at least one lens, which comprises at least one surface or face of aspherical shape. It will also be explained more simply that the optical means comprise at least one lens with at least one aspherical surface or that the optical means comprise at least one aspherical surface. The optical device is arranged to be positioned between the indicator and the observer. It is therefore substantially superimposed on the indicator to be observed, that is to say it is substantially above the indicator.

Such an aspherical-shaped face is more specifically defined as including at least one cross section through a vertical plane containing an optical axis of the optical device in the vertical direction z, at least one contour line of the cross section being a curve that can be defined by the following equation (1):

And wherein the following conditions are confirmed: taper constant k or aspheric coefficient alpha_iAt least one value of (i-4, 6.) is not equal to zero.

By makingby usingTo indicate the angular offset of the above-mentioned vertical plane with respect to a reference direction at right angles to the optical axis of the vertical direction z,In this equation (1) are the usual cylindrical coordinates, R is the nominal radius of curvature, k is the taper constant, α_4，6，...Is an aspherical coefficient. Note also that the nominal radius of curvature R corresponds to the radius of curvature at the location where R is 0.

The contour line can be formed without considering the angleIn the particular case defined by equation (1), the contour exhibits rotational symmetry about the optical axis in the vertical direction z.

If all aspheric coefficients α_4，6，...Are all zero, the taper constant k affects the type of cross-sectional shape. The cross-section is circular when k is 0, parabolic when k is-1, hyperbolic when k < -1, and elliptical otherwise.

Note that the aspherical surface coefficient α_4，6，...It is helpful to adjust the appearance of the initial section, that is, the section defined by the same equation (1) in the case where all aspheric coefficients are zero. This adjustment becomes larger as the distance is farther from the origin (that is, becomes larger as r is larger).

Thus, the aspherical surface according to the invention comprises at least one section having the following shape:

Parabolic, hyperbolic or elliptical, or

-parabolic, hyperbolic or elliptical, modified by at least one non-zero aspheric coefficient, or

-a circle adjusted by at least one non-zero aspheric coefficient.

The invention therefore also relates to an optical device for a timepiece, in which at least one aspherical surface comprises at least one section through a vertical plane, at least one contour of which is a curve that takes the shape of a part of a circle adjusted by aspherical coefficients.

The invention also relates to an optical device for a timepiece, in which at least one aspherical surface comprises at least one section through a vertical plane, at least one contour of which is a curve that takes the shape of an ellipse, a parabola or a hyperbola.

Thus, a significant improvement in legibility and/or visibility of the marking has been observed on the basis of such an optical device having at least one aspherical surface. In practice, the exact aspherical shape of the surface or face of the lens can be determined according to several methods.

According to applicants preferred method, the aspherical shape may be defined based on an optimization algorithm consisting of two consecutive steps. In a first step, a full search in the space of the aspherical surface can determine the lens group with the stronger optical potential. This search is based on stochastic algorithms, in particular latin hypercube sampling and genetic algorithms. In a second step, the local search around the representation of each suitably determined group can be iterated to optimize the surface of the lens until a satisfactory solution appears. For example, the method used in this second step may be a variation of the Nelder-Mead simplex optimization method.

"satisfactory solution" is understood to mean a solution capable of at least partially resolving the conflicting objectives described below:

-increasing the interval [ θ min, θ max ] as much as possible;

-whatever the angle θ between θ min and θ max, the mark concerned is enlarged as always as possible;

-minimizing distortion of the marks that could cause erroneous reading of the mark concerned.

Thus, with this method, it seems, according to the studies of the applicant, that it is possible to maximize the spacing [ θ min, θ max ] by about 100% with respect to the spacing known in the prior art, while always enlarging the markers involved and, at the same time, minimizing the distortions of the markers.

More specifically, an optical device comprising at least one lens having at least one aspherical surface whose curvature decreases with the variation of r constitutes a particularly suitable solution capable of solving the above-mentioned objects.

Fig. 4 to 9 show in more detail an embodiment of the invention comprising associating at least one optical device according to the invention with a timepiece lens. The lens extends substantially horizontally. To simplify reading, the same reference numerals will be used to refer to the same or similar elements in different embodiments.

According to a first embodiment, illustrated in fig. 4 to 7, the optical device 10 comprises a single lens 21, which is substantially above the indicator 2 (for example, arranged on the dial of a timepiece).

Fig. 4 shows an optical device 10 added to the top surface 4 of the watch lens 3, according to which the watch lens 3 is substantially flat and horizontal. The optical device comprises a lens 21 having a substantially horizontal bottom surface 13 fixed to the top surface 4 of the watch lens 3. This fixing may be done in any way, for example by gluing. As can be seen in fig. 4, the cross section of the optical device 10 is defined by a top curve corresponding to equation (1) previously explained, wherein at least one value of the taper constant or aspheric coefficient is not equal to zero. In other words, the top surface 14 of the lens 21 of the optical device 10 is given its aspherical character, while its bottom surface 13 is substantially flat.

Fig. 5 shows a second modification of the optical device 10 according to the first embodiment of the present invention. This second variant differs from the first variant of fig. 4 in that the optical device 10 and the lens 3 are integrally formed in one piece. In other words, the optical device 10 is no longer a distinct element fixed to the lens. It forms a protrusion above the top surface 4 of the lens 3 as part of the lens 3 itself to form the overall same top shape as in the case of the first variant of figure 4.

Fig. 6 shows a third variant embodiment, in which the optical device 10 and the lens 3 are integrally formed in a single piece. However, in this variant, the optical means are shaped in the thickness of the lens 3. Thus, the aspheric top surface 14 of the lens 21 remains at a level lower than the top surface 4 of the optic or substantially the same as the level of the top surface 4 of the optic. Note that the top surface 14 still has a similar shape to the first two variations.

fig. 7 shows a fourth variant embodiment, in which the optical means 10 are shaped in the thickness of the lens 3 from the bottom surface 5 of the lens. In this embodiment, the optical device 10 and the lens 3 are still integrally formed as one piece. The bottom surface 13 of the lens 21 of the optical device 10 has an aspherical shape.

The applicant's studies have shown that the optical device according to the first embodiment provides a magnified reading of the mark, which is visible in an angular range increased by about 100% compared to the prior art.

In the last three variant embodiments respectively associated with fig. 5 to 7, the optical device 10 can be formed in the lens by any method, in particular by a machining method, for example by a laser such as a femtosecond laser and/or by an etching method.

According to a second embodiment, shown in fig. 8 and 9, the optical device 10 comprises two superposed lenses 21, 22, respectively provided on the top surface 4 and on the bottom surface 5 of the timepiece lens 3.

Thus, fig. 8 shows a first modification of the second embodiment. Thus, similar to the embodiment of fig. 7, the optical means comprise a first lens 21 shaped in the bottom surface of the optic 3. The first lens is aspherical, that is to say it comprises at least one aspherical surface. In addition, the optical device 10 includes a second lens 22 secured to the top surface 4 of the optic and overlying the first lens. The second lens 22 is spherical. Which adds a second magnification effect that complements the magnification effect of the first lens.

Fig. 9 shows a second variant embodiment, which differs from the first variant in that the second lens 22 is also aspherical. Advantageously, such a lens 22 supplements the magnification effect provided by the first lens 21, while reducing the distortion effect produced by the first lens 21.

this second lens 22 is similar to the lens of the optical device of the first variation of the first embodiment of fig. 4. As a variant, this second lens may be similar to the lenses of the optical devices of the two other variants of the first embodiment of fig. 5 and 6. The first lens 21 remains the same as in the first embodiment of fig. 8.

In all cases, the optical device and/or at least one lens it comprises occupy a surface area less than or equal to 30% of the total surface area of the lenses of the timepiece.

The applicant's studies have shown that the optical device according to the second embodiment provides a magnified reading of the indicia, improved with respect to the reading provided by the optical device according to the first embodiment, and visible in an angular range increased by about 100% with respect to the prior art.

Of course, the invention is not limited to the described embodiments. In particular, these embodiments may be combined. Furthermore, the optical device has been described on the basis of one or two superposed lenses. As a variant, the optical means may comprise three or more lenses. The lenses at least partially overlap. In addition, a lens has been disposed on the top or bottom surface of the optic. As a variant, such a lens may be positioned at any point in the thickness of the lens. The lens or lenses may even extend over the full thickness of the lens.

Moreover, in all the variants represented, the optical device finally comprises a lens having an aspherical portion, in particular having an aspherical surface. This aspheric surface is convex. As a variant, the lens may be biconvex, that is to say have two opposite convex faces. Furthermore, both faces may be aspherical. Thus, the optical device may include two aspheric surfaces, top and bottom.

Furthermore, the horizontal contour of the optical device, i.e. the contour defined by the section of the optical device along a horizontal plane or the projection of the optical device on a horizontal plane, in particular the plane P of a timepiece, may take different shapes. For example, it may be circular, square, rectangular or oval.

The lens of the optical device may be made of a hard crystalline material, in particular corundum, sapphire or spinel. Alternatively, the lens of the optical device may be made of glass, in particular of mineral glass. As a further alternative, the material forming the lens of the optical device may be composed of a polymer, in particular Polymethylmethacrylate (PMMA). In any variant, the lens of the timepiece can also be made of a hard crystalline material, in particular corundum, sapphire or spinel. Likewise, the lens can alternatively be made of glass, in particular mineral glass, or of a polymer, in particular polymethyl methacrylate (PMMA). One or more of the lenses may be made of the same or different material as the optic. Finally, at least one lens is advantageously made of a rigid material. This rigid material is not deformable and it is not designed to deform in normal use of the timepiece. It has little or no plasticity range. The at least one lens may advantageously be formed entirely of such rigid and non-deformable material. As a variant, at least one lens comprises at least one outer casing at least substantially completely enclosing it, and is formed of a non-deformable rigid material.

In all embodiments, the optical device has been associated with the lens of the timepiece. In these embodiments, the optical device is fixed relative to the lens and the timepiece. As a variant, the optical means may be provided in the timepiece independently of the lens. For example, it may be arranged between the dial comprising the indicator and the lens of the timepiece. In addition, the optical device is already fixedly arranged in the timepiece. As a variant, it can be moved with respect to the timepiece, for example by being mounted on the hands of the timepiece.

The indicator 2 of the timepiece can be designed for displaying any type of indicia, in particular an hour indicia (for example, the display of hours or minutes), or any type of time-derived indicia (for example, a calendar indicia, for example, an indicia of the date of the month, of the day, of the month or of the phase of the month). The indicator may be mobile and may be designed for displaying a specific mark in a window of the dial. In this case, the optical means are advantageously superimposed on the dial window in order to optimize the visibility of the indicia present in the window.

Alternatively, the indicator may be fixed and may, for example, comprise several different markings added at different locations on the dial plate. In this case, the optical device may be moved relative to the pointer in order to optimize the visibility of the mark to be considered, which is only a part of the plurality of marks of the pointer.

In all cases, the indicia may be annotations such as numbers, letters, or colors. The indicator is advantageously positioned in a plane parallel to the plane of the optic and/or the plane of the lens of the optical device. The "plane of the lens" advantageously corresponds to a plane parallel to and/or passing through the top surface of the lens.

Finally, the lens may:

-a case participating in forming a seal and a fixing of a timepiece, and/or

Arranged parallel to a plane in which there is an indicator to be magnified, and/or

-comprising at least one lens having at least one aspherical surface occupying a surface area less than or equal to 30%, or less than or equal to 20%, or less than or equal to 10%, and/or of the total surface area of the top surface of the optic

At least one lens having at least one aspherical surface, which is superimposed in a substantially vertical direction on at least one indicator of the timepiece to be magnified, and/or

-comprising at least one lens having at least one aspherical surface and being fixed with respect to the ophthalmic lens.

in addition, as previously mentioned, an optical device is considered to be aspherical when it includes at least one face having at least one aspherical portion. Thus, according to the exemplary embodiment shown in fig. 10, such an aspherical surface 13, 14 may for example comprise a cross section whose contour comprises a portion of a circle 17 in its central part and comprises at least one inflection point 18. At the inflection point 18, the concavity or convexity of the contour of the cross section changes.

Finally, the aspheric surface of the optical device according to embodiments of the present invention may or may not have rotational symmetry about a central vertical axis. Furthermore, an optical device according to an embodiment of the present invention may or may not have symmetry with respect to a vertical mid-plane.