EP2206006A1

EP2206006A1 - Deformable mirror with distributed stiffness, tool and method for producing such a mirror

Info

Publication number: EP2206006A1
Application number: EP08871239A
Authority: EP
Inventors: Frédéric ROOMS; Sébastien CAMET; Jean-François CURIS
Original assignee: UJF-Filiale; UJF FILIALE
Current assignee: UJF-Filiale; UJF FILIALE
Priority date: 2007-11-02
Filing date: 2008-10-31
Publication date: 2010-07-14
Also published as: JP2011503641A; US8810891B2; FR2923301B1; CA2703870A1; FR2923301A1; JP5452497B2; US20110019295A1; WO2009092901A1

Abstract

The present invention relates to a deformable mirror (1) comprising a deformable membrane (2) with a reflecting face (3) and an opposite face (4), a rigid plate (5) and a structure of at least one actuator (9) at least a part of which is fixed to the rigid plate (5) and able to locally deform the membrane (2), characterized in that the deformable mirror (1) also comprises a not necessarily uniform adhesive layer (11) against the opposite surface (4) of the membrane (2), and a structure of at least one flexible coupling means (12) comprising a mechanical connection means (21) and upper (22) and lower (23) linking means coupling respectively the upper (13) and lower (14) ends of the mechanical connection means (12) to the adhesive layer (11) and to the rigid plate (5). The invention also relates to a tool and a method making it possible to produce such a mirror.

Description

DEFORMABLE MIRROR WITH DISTRIBUTED STIFFNESS, TOOL AND METHOD FOR

MAKE SUCH A MIRROR

The present invention relates to a deformable mirror with distributed stiffness, a tool and a method for producing such a mirror.

TECHNICAL AREA

The present invention relates to the field of deformable mirrors with actuators or actuators.

STATE OF THE PRIOR ART

Known deformable membrane mirrors having an actuator structure are known in the state of the art. These mirrors are characterized by a resonant frequency which decreases when the diameter of the membrane increases, which makes it impossible to produce deformable mirrors of large diameter having significant performance in terms of frequency response. The deformable mirrors according to the state of the prior art are therefore limited to an arbitration between the diameter of the membrane, its voltage and its resonant frequency. It is indeed necessary, in order to obtain a sufficient resonant frequency, to reduce the diameter or to increase the tension of the membrane. This limitation comes from the excessive stiffness of the mirror, which during a local deformation thereof does not sufficiently retranscribe the vibration in a localized manner. It has been proposed in the state of the art a solution described in the patent application WO 2005/050283 corresponding to an actuator structure for the surface deformation further comprising a deformable membrane, an actuator mesh located in front of the opposite side of the membrane, each actuator having an actuating surface, a mesh of actuating connections, each actuating connection being coupled to an actuating surface respectively of one of the actuators of the mesh and respectively a point of the second surface opposite to the actuating surface each actuating connection having anisotropic rigidity and transmitting a movement perpendicular to the second surface.

This solution, if it makes it possible to optimize the resonant frequency of the membrane, proves difficult to implement. More particularly, the assembly of the various elements is made difficult, which implies high mechanical tolerances. Also, the deformable mirror according to this solution comprises several blocks of elements. Finally, this solution requires the use of a second deformable surface, which generates a significant additional cost.

It has also been proposed in the state of the art a solution described in US Pat. No. 5,831,780 corresponding to a mirror support system comprising a base, a thin optical substrate having a first light collecting surface and an opposite rear surface, means flexible coupling of the rear surface of the substrate and the base to one another, and at least one actuator interposed in the flexible coupling means, connected between the base and the optical substrate to modify in a controlled manner the shape of said optical substrate, said coupling means flexible member comprising a flexible foundation which only partially contains at least one actuator.

The main disadvantage of this solution is that its embodiment is very difficult to implement. It can only be applied for mirrors of diameter of the order of several tens of centimeters. The number of degrees of correction by the actuators is also low because this solution is only intended to compensate for deformations that would have suffered the mirror when it is sent into space.

Thus, the disadvantage of prior solutions lies in the impossibility, for a given mirror diameter, of obtaining significant resonant frequencies while maintaining a sufficient number of degrees of correction and an ease of realization of the mirror.

OBJECT OF THE INVENTION

The object of the present invention is to overcome the disadvantages of the state of the art, by proposing a flexible structure offering a distribution of the stiffness of the membrane over its entire surface, while allowing a simple assembly of all components of the deformable mirror and reducing the mechanical tolerance requirements at the actuators.

To this end, the present invention proposes a deformable mirror comprising a deformable membrane with a reflecting face and an opposite face, a rigid plate and a structure of at least one actuator of which at least a portion is fixed to the rigid plate and adapted to locally deforming the membrane, characterized in that the deformable mirror also comprises an adhesive layer not necessarily uniform against the opposite surface of the membrane, and a structure of at least one flexible coupling means comprising a mechanical connection means and upper and lower connection means respectively coupling the upper and lower ends of the means of mechanical connection to the adhesive layer and the rigid plate.

According to a particular embodiment, all the flexible coupling means are arranged between the actuators.

According to another particular embodiment, at least one of the flexible coupling means (12) is disposed at an actuator (9).

According to another particular embodiment, all the flexible coupling means (12) are arranged at the level of the actuators (9).

Advantageously, the mechanical connection means of at least a portion of the flexible coupling means is a rigid rod along a vertical axis on the surface of the rigid plate.

Advantageously, a part of the flexible coupling means arranged at the level of the actuators also comprises a second connection means separating at least a portion of

The actuator of the adhesive layer, this second connecting means being flexible.

Advantageously, a part of these flexible coupling means arranged at the level of the actuators also comprises a second mechanical connection means separating the connecting means from the adhesive layer, this second mechanical connection means being able to penetrate into said adhesive layer.

Preferably, the second means of mechanical connection of at least a part of these flexible coupling means arranged at the level of the actuators is constituted a rigid rod along a vertical axis on the surface of the rigid plate.

According to a particular mode of implementation, at least a part of the flexible coupling means is fixed to a second rigid plate located below the first rigid plate, said first rigid plate being pierced at these so-called flexible coupling means .

According to another particular mode of implementation, at least a part of the flexible coupling means arranged at the level of the actuators is fixed to a second rigid plate located below the first rigid plate, the first rigid plate and the actuator centers. corresponding and fixed to the second rigid plate being pierced at these so-called mechanical connection means. Advantageously, the lower connection means consists of a layer of adhesive material applied in a hole drilled in the second rigid plate to a depth that can be parameterized in advance.

According to a particular embodiment, at least one flexible coupling means comprises between the mechanical connection means and the lower connecting means an adjustable chamber.

According to a first embodiment, each lower connecting means is a rigid bonding means consisting of an adhesive material having a polymerization time greater than one minute, and each upper bonding means is a flexible bonding means consisting of a adhesive material by elastomer.

According to a second embodiment, each lower connecting means is a flexible connecting means consisting of an elastomeric adhesive material, and each upper connecting means is a rigid connecting means consisting of an adhesive material having a polymerization time greater than one minute. According to a third embodiment, each of the lower and upper connection means is a flexible connection means consisting of an elastomeric adhesive material. The invention also proposes a tool for producing such a deformable mirror, further comprising:

- A lighting device for producing a parallel light beam;

a wavefront sensor; a separator cube making it possible to separate the direction of the light coming from the lighting device between the deformable mirror and the wavefront sensor;

- a deposit device; a computer adapted to receive data transmitted by the wavefront sensor and the setpoint device; a control box in conjunction with said computer and able to separately control each actuator of the deformable mirror to control the local deformation associated with each actuator of said deformable mirror.

Finally, the invention proposes a method of pre-forming such a deformable mirror with the aid of a production tool, successively comprising the following steps

The adhesive layer is attached to the deformable membrane;

the upper connecting means is attached to the adhesive layer

the upper end of each flexible coupling means is coupled to the adhesive layer via the upper connecting means;

the lower end of each flexible casting means is fastened to at least one of the rigid plates via the rigid lower connection means, the said connecting means lower rigid being made of an adhesive material having a polymerization time greater than one minute; during the polymerization of the adhesive material constituting the rigid lower connection means, a closed loop controls and optimizes the restoring forces of the actuators of the deformable mirror so as to pre-form the membrane of the mirror in a predetermined shape, for the duration of the said polymerization.

It will be understood that a link is flexible if the elongation of this link is greater than or equal to 5 nanometers under the action of a force compatible with that which can be produced by the actuator. This displacement corresponds to what is observable in the state of the art wavefront sensors. It will also be understood that a link is rigid if this elongation is less than 5 nanometers under the same conditions.

The invention can be implemented with actuators or actuators. Thus we will speak later only of actuators.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be better understood on reading the detailed description which follows, relating to nonlimiting examples of embodiment, accompanied by appended figures which represent, respectively:

- Figure 1, a three-dimensional view of a deformable mirror according to a first embodiment of the invention, with mechanical connection means to a rod around the actuators, Figure 2, a top view of a structure of ¹ magnetic actuators according to the first mode of embodiment of the invention,

FIG. 3, a sectional view of a deformable mirror according to the first embodiment of the invention,

- Figure 4, a sectional view of a deformable mirror according to a second embodiment of the invention, with means for mechanical connection to a rod against the actuators,

- Figure 5, a sectional view of a deformable mirror according to a third embodiment of the invention, with mechanical connection means comprising a double layer of flexible glue,

FIG. 6, a sectional view of a deformable mirror according to a fourth embodiment of the invention, with mechanical connection means with two rods; FIG. 7, a sectional view of a deformable mirror; according to a fifth embodiment of the invention, with actuators and the corresponding mechanical connection means distributed over two rigid plates;

- Figure 8, a sectional view of a deformable mirror according to a sixth embodiment of the invention, with the lower ends of the mechanical connection means with two rods under the actuators,

- Figure 9, a sectional view of a deformable mirror according to a seventh embodiment of the invention, with the lower ends of the mechanical connection means to a rod under the actuators, Figure 10, a sectional view of a deformable mirror according to an eighth embodiment of the invention, with the rigid upper connecting means and the flexible lower connecting means, FIG. 11, a sectional view of a deformable mirror conforming to a ninth mode embodiment of the invention, with the flexible upper and lower connection means, FIG. 12 is a sectional view of a deformable mirror according to a tenth embodiment of the invention, with a flexible glue depth parameterized in advance, and FIG. 13, a device for realizing and controlling a deformable mirror according to the invention.

DETAILED DESCRIPTION OF PARTICULAR EMBODIMENTS

Figures 1, 2 and 3 show views of a deformable mirror according to a first embodiment of the invention. This mirror (1) consists of a deformable membrane (2), a rigid plate (5), a structure of magnetic actuators (9) and a structure of flexible coupling means (12).

The deformable membrane (2) is an optical substrate having two surfaces: a reflecting surface (3) and an opposite surface (4). In the present embodiment, the substrate is of silicon type and the membrane (2) has a thickness of 20 .mu.m. In another embodiment, it is of Kapton type.

The rigid plate (5) is a plate disposed parallel to the surface of the membrane (2) initially undeformed. It can be for example made of aluminum or any other material.

Each magnetic actuator (9) comprises a magnet (7), a coil (8) and a device (not visible) for controlling the magnetic field created by the coil (8).

Each magnet (7) is integral with the membrane (2). Each coil (8) is fixed at least in part to the rigid plate (5) facing the corresponding magnet (7). In this embodiment, the magnets (7) have a diameter of 850 .mu.m and a thickness of 250 .mu.m, the coils (8) have an external diameter of 1.7 mm. As a function of the magnetic field created by the coil (8) in the vicinity of the magnet (7) and controlled by the user of the deformable mirror (1), said magnet (7) is attracted or pushed back towards said coil (8). This magnetic field causes the magnet (7) to move in the axis perpendicular to the surface of the rigid plate (5). Said magnet (7) being integral with the membrane (2), the latter is deformed locally at the area covered by said magnet (7). The control device of the magnetic actuators operates in a closed loop on a set point for giving a particular shape to the membrane (2).

Advantageously, the magnetic actuators (9) are arranged on the entire surface covering the deformable membrane (2) in a uniformly distributed matrix. The influence of each of the actuators on the deformation of each of the corresponding areas of the membrane (2) is thus identical. The influence functions of the actuators thus have identical spatial extensions. The inter-actuator distance is 2.5mm in this embodiment.

The adhesive layer (11) is applied against the opposite surface (4) of the membrane (2). It allows both to solidify the membrane (2) and to fix each magnet (7) in order to easily assemble the various elements of the mirror. It is not necessarily uniform and may indeed not be homogeneous depending on the pressure exerted on it. Its thickness is 100 μm in this embodiment. This adhesive layer (H) consists of a flexible adhesive material. This adhesive material is an elastomer glue, whose family of silicone or polyurethane glues meets the needs thanks to their high elasticity. Thus constituted, the adhesive layer (11) is may not be homogeneous depending on the forces applied against it.

Each flexible coupling means (12) allows, during a local deformation of the membrane (2) by a magnetic actuator, to distribute the stiffness of the membrane so as to improve its frequency response.

Each flexible coupling means (12) makes it possible to form a flexible connection between the rigid plate (5) and the membrane (2). This flexible coupling means (12) has two ends for this purpose: an upper end (13) coupled to the membrane (2) and a lower end (14) coupled to the rigid plate (5). Each flexible coupling means (12) is disposed between the magnetic actuators.

More specifically, each flexible coupling means (12) comprises a mechanical connection means (21), which is a rigid rod disposed along the vertical axis on the surface of the rigid plate (5). Each rigid rod has a diameter of between 100 and 200 μm in this embodiment. Each flexible coupling means (12) also comprises two upper (22) and lower (23) connecting means respectively disposed at its upper (13) and lower (14) ends. The lower link means (23) is rigid to lock the lower end (14) of said rigid rod (21). Each rigid connecting means (23) is embedded in a bore of the rigid plate (5) so as to release the tolerances along the length of the rod. This rigid connection means (23) consists of an adhesive in which is dipped said rigid rod (21). In another embodiment, the rigid connection means (23) is an adhesive pad fixed to the rigid plate (5).

This glue has a low thermal expansion so as to protect itself from heat dissipation in the coil (8) due to the Joule effect causing a displacement of the rod (21) and therefore an uncontrollable deformation of the membrane (2). It also has a high polymerization time, which allows to shape the membrane (2) before said adhesive hardens. This makes it possible to release constraints on geometric tolerances.

This glue belongs to the family of "epoxy" glues, known for their low thermal expansion. More particularly, it has a polymerization time greater than one minute, to allow the assembly of the elements and to give a particular initial shape to the mirror. The glue is initially placed in the hole of the rigid plate (5), then a polymerization is carried out when the rigid rod is immersed in the glue.

The lower connecting means (22) is flexible in order to perform a mechanical return function. For this purpose, said flexible connecting means (22) is a pad of adhesive material. This adhesive material is a flexible adhesive whose family of silicone or polyurethane glues meets the needs thanks to their high elasticity.

The mechanical return force of the spring constituted by the glue is easily parameterized via the diameter of the rod. Indeed, the restoring force is proportional to the contact surface: the smaller the contact surface, the greater the displacement of the membrane (2), other constant glue parameters (thickness, force of the actuator, etc.). Also, this mechanical restoring force is parameterized by the quantity of glue, at other constant parameters. Indeed, the stroke increases when the amount of glue increases, since the material is flexible and therefore the thicker the glue pad is and the more the deformation is great for the same relative elongation (the stiffness of the spring also decreases).

The mechanical connection means constituting the flexible coupling structure of the mirror have the advantage of being easily reproducible and of allowing more localized deformations.

The present embodiment also makes it possible to increase the inter-actuator stroke by reducing the mechanical coupling. It also makes it possible to increase the resonance frequency of the membrane significantly while maintaining the linearity of the mirror, the resonance frequency (with a constant material) depending only on the distance between the rods, and no longer on the dimensions of the diaphragm. mirror.

FIG. 4 represents a sectional view of a deformable mirror according to a second embodiment of the invention. Such a mirror (1) differs from the mirror according to the first embodiment in that the flexible coupling means (12) are arranged no longer around the magnetic actuators (9) but at their levels.

The upper connecting means (22) is applied directly under the magnet (7), and the upper end of the rigid rod (21) is fixed on it so as to provide a mechanical return function.

The lower connecting means (23) is embedded in the coil (8). Indeed, the coils (8) do not have copper wire in their center. Thus a hole is drilled in the center of said coil (8), the adhesive is initially placed in the hole of the coil (8), and a polymerization is performed when the rigid rod is immersed in said adhesive.

A deformable mirror (1) according to this embodiment has improved performance at the level of the spatial extension of the influence functions. This improvement is due to the fact that the withdrawal force is located at the same place as the application force. It is therefore easier to avoid a local deformation of the membrane at the rod relative to the mirror according to the first embodiment of the invention.

FIG. 5 represents a sectional view of a deformable mirror according to a third embodiment of the invention. Such a mirror (1) differs from the mirror according to the second embodiment in that a second flexible connection means (22 ') is placed between the magnet (7) and the adhesive layer (11).

This embodiment implements a double layer of flexible glue (22,22 ') surrounding the magnet (7), which makes it possible to accentuate the deformation of the membrane (2) while keeping the other parameters of the mirror (1). ) constant.

FIG. 6 represents a sectional view of a deformable mirror according to a fourth embodiment of the invention. Such a mirror (1) differs from the mirror according to the third embodiment in that a second rigid rod (21 ') is placed between the second flexible connection means (22') and the adhesive layer (11). Advantageously, the first and second rigid rods (21, 21 ') are of equal length.

The present invention according to this embodiment is distinguished in that the rigid rods (21 ') penetrate directly into said adhesive layer (11). Thus, this embodiment makes it possible to reduce the impression effect on the membrane (2), since the impression of the second rigid rod (21 ¹ ) is smaller than that of the magnet (7). Also, the flexible double bond of glue produced makes it possible to increase the deformation of said membrane (2). Figure 7 shows a sectional view of a deformable mirror according to a fifth embodiment of the invention. Such a mirror (1) differs from the mirror according to the fourth embodiment in that a second rigid plate (6) is disposed under the first rigid plate (5). This second rigid plate (6) also contains coils (8) of the structure of magnetic actuators to which rigid rods (21) are attached. The first rigid plate (5) has for this purpose drilling holes at each flexible coupling means (12) connected to the second rigid plate (6).

This embodiment makes it possible to distribute the coils (8) over two stages and thus to reduce the inter-actuator distance. Advantageously, the actuators may be arranged on a number of plates greater than two, so as to bring said actuators even closer. A limitation however appears in the number of rigid plates, since ¹ then the length of the rigid rods becomes important and there appears a possible risk of buckling.

Finally, also advantageously, the magnets (7) are arranged at different heights with respect to the membrane (2), which reduces the size and therefore can reduce the distance between the actuators.

FIG. 8 represents a sectional view of a deformable mirror according to a sixth embodiment of the invention. Such a mirror (1) differs from the mirror according to the fourth embodiment in that the lower end (14) of the flexible coupling means (12) is fixed not to the first plate (5) but to the second plate ( 6) located below said first plate (5).

For this purpose, the coil (8) is pierced along the axis perpendicular to the surface of the first rigid plate (5), and said first rigid plate (5) is also pierced in the continuation of the drilling of said coil (8). The first rigid rod (21) thus passes through the first plate (5) and the coil (8). The coupling to the second plate (6) of the lower end (14) of the flexible coupling means (12) is performed by a rigid connection means (23) according to the previous embodiments.

A mirror (1) according to this embodiment has the advantage of moving the connection points (23) away from the mechanical connection means (21) with respect to the heat dissipation zone around the coil (8). . The phenomena of thermal expansion are thus significantly reduced.

FIG. 9 represents a sectional view of a deformable mirror according to a seventh embodiment of the invention. This embodiment comprises the features of the preceding embodiment, applied to a deformable mirror (1) whose flexible coupling means (12) comprises a single rigid rod (21) according to the second embodiment for example.

FIG. 10 represents a sectional view of a deformable mirror according to an eighth embodiment of the invention. This embodiment is similar to the previous embodiment of the present invention. The difference lies at the level of the connecting means (22,23).

Indeed, the lower connecting means (23) and upper (22) are respectively rigid and flexible. The characteristics of the connecting means (22,23) are thus reversed with respect to the previous embodiments.

In other particular embodiments, the characteristics of the connecting means (22, 23) are inverted on each of the other embodiments described.

Figure 11 shows a sectional view of a deformable mirror according to a ninth embodiment of the invention. This embodiment is similar to the previous embodiment of the present invention. The difference lies at the level of the connecting means (22,23). Indeed, the lower link means (23) and upper (22) are respectively flexible.

In other particular embodiments, the connecting means (22, 23) are flexible on each of the other embodiments described.

Figure 12 shows a sectional view of a deformable mirror according to a tenth embodiment of the invention. This embodiment is similar to the eighth embodiment of the present invention. The difference is at the level of the flexible connection means (22).

Said flexible connection means (22) consists of a drilling hole in the second rigid plate (6). The hole is not completely filled with flexible adhesive material, which is placed at a certain depth set in advance.

Unlike previous embodiments where the work is in tension / compression, the glue being placed on the rod, this embodiment allows shear work. The return force is then proportional to the contact surface, so the diameter of the rod and the height of the glue pad.

This embodiment thus renders the actuator actuator biasing force while controlling the thickness of adhesive material.

It is therefore possible furthermore to modify the strokes of each of the actuators. Indeed, in a circular membrane, the strokes are always weaker near the edges because of mechanical connections. Thus the application of weaker fasteners on the edges than in the center makes it possible to increase the homogeneity of the strokes of each of the actuators.

In another embodiment, at least a portion of the rigid rods is attached to a hydraulic or gaseous chamber, located below the corresponding rod and for constraining the shape of the deformable membrane.

In an advantageous embodiment of the present invention, the matrix of magnetic actuators is separated from the rigid plate (5) so that only the deformable membrane (2) is fixed to said rigid plate (5). This embodiment has the advantage of allowing custom manufacturing of the shape of the deformable mirror corresponding to a precise specification.

Figure 13 illustrates a tool for producing a deformable mirror according to any one of the above embodiments.

This production tool comprises: a lighting device (30) for producing a parallel light beam; a wavefront sensor (31);

- a separator cube (32) for separating the direction of light from the illumination device (30) between the deformable mirror (1) and the wavefront sensor (31); a setpoint device (33);

a computer (34) capable of receiving data transmitted by the wavefront sensor (32) and the setpoint device (33); a control box (35) in connection with said computer and able to separately control each actuator of the deformable mirror (1) in order to control the local deformation associated with each actuator of said deformable mirror;

(1).

A method for pre-forming a deformable mirror (1) according to any one of the embodiments above, uses a production tool in accordance with that also described above. It requires the use of a rigid lower connection means (23) and made of an adhesive material having a polymerization time greater than one minute. It comprises successively the following steps:

the adhesive layer (11) is fixed to the deformable membrane (2);

- The upper connecting means (22) is attached to the adhesive layer the upper end (13) of each flexible coupling means (12) is coupled to the adhesive layer (11) via the upper connecting means (22);

the lower end (14) of each flexible coupling means (12) is fixed to at least one of the rigid plates (5, 6) via the rigid lower connection means (23), the said rigid lower link means (23) consisting of an adhesive material having a polymerization time greater than one minute; during the polymerization of the adhesive material constituting the rigid lower connection means, a closed loop controls and optimizes the restoring forces of the actuators of the deformable mirror so as to pre-form the mirror membrane according to a predetermined shape, throughout the duration of said polymerization.

In accordance with the above embodiments of the mirror, the adhesive making the rigid connection (23) has a polymerization time of a few minutes. This duration can be from one minute to three hours, depending on the time required for the installation and calibration of the deformable mirror, and more particularly the times of the measurements of the control and interaction matrixes involved.

This method, and the device that it implements, allow for example to put the mirror in planar form without having to control it. This overcomes a disadvantage of magnetic deformable membrane mirrors of the state of the art, which are known to induce aberrations at rest, making optical alignment difficult. In addition, once the polymerization is complete, this form is obtained passively, that is to say without energy consumption and without calculator.

They also allow to give any form to the mirror. This form can be for example a parabola or a portion of sphere.

Such an embodiment method can be used judiciously to produce mirrors of any fixed shape. The magnets are glued on the membrane and the shape of the mirror is imposed by the forces applied during the polymerization. The coils are also attached to the rigid plate, however once the fixed shape of the mirror obtained, they are no longer useful. Thus, advantageously, the coils of the structure of ^one actuator can be arranged on a comb-shaped element, The element being able to be introduced and then removed from the rigid plate. This saves the cost of the coils.

The previously described embodiments of the present invention are given by way of examples and are in no way limiting. It is understood that the skilled person is able to realize different variants and different combinations of these embodiments of the invention without departing from the scope of the invention.

Thus, the previously described embodiments apply identically to non-magnetic actuators, for example mechanical and piezoelectric actuators, as well as to any combination of actuators of different types.

Finally, the invention can be implemented to give an initial shape to the mirror during the polymerization step rigid links, this shape can be modified later or fixed once and for all.

Claims

1 - deformable mirror (1) comprising a deformable membrane (2) with a reflecting face (3) and an opposite face (4), a rigid plate (5) and a structure of at least one actuator (9) of which at least a part is fixed to the rigid plate (5) and adapted to locally deform the membrane (2), characterized in that the deformable mirror (1) also comprises an adhesive layer (H) not necessarily uniform against the opposite surface (4) of the membrane (2), and a structure of at least one flexible coupling means (12) comprising a mechanical connection means (21) and upper (22) and lower (23) connecting means respectively coupling the upper ends (13) and lower (14) of the mechanical connection means (12) to the adhesive layer (11) and the rigid plate (5).

2 - deformable mirror (1) according to the preceding claim, characterized in that all the flexible coupling means (12) are arranged between the actuators (9).

3 - deformable mirror (1) according to claim 1, characterized in that at least one of the flexible coupling means (12) is disposed at an actuator (9).

4 - deformable mirror (1) according to the preceding claim, characterized in that all the flexible coupling means (12) are arranged at the actuators (9).

5 - deformable mirror (1) according to at least one of the preceding claims, characterized in that the means mechanical connection (21) of at least a portion of the flexible coupling means (12) is a rigid rod along a vertical axis on the surface of the rigid plate (5).

6 - deformable mirror (1) according to at least one of claims 3 to 5, characterized in that at least a portion of the flexible coupling means (12) disposed at the actuators (9) also comprises a second means of link (22 ') separating at least a portion of one actuator (9) from the adhesive layer (11), the second connecting means (22') being flexible.

7 - deformable mirror (1) according to the preceding claim, characterized in that at least a portion of these flexible coupling means (12) disposed at the actuators (9) also comprises a second mechanical connection means (21 ') separating the connecting means (22 ') from the adhesive layer (11), the upper end of the flexible coupling means (12) being thus able to penetrate into said adhesive layer (11).

8 - Deformable mirror (1) according to the preceding claim, characterized in that the second mechanical connection means (21 ¹ ) of at least a portion of these flexible coupling means (12) arranged at the actuators (9) is consisting of a rigid rod along a vertical axis on the surface of the rigid plate (5).

9 - deformable mirror (1) according to at least one of claims 3 to 8, characterized in that at least a portion of the flexible coupling means (12) is fixed to a second rigid plate (6) below the first rigid plate (5), said first rigid plate (5) being pierced at said so-called flexible coupling means (12). 10 - deformable mirror (1) according to at least one of claims 3 to 9, characterized in that at least a portion of the flexible coupling means (12) arranged at the actuators (9) is fixed to a second plate rigid (6) located below the first rigid plate (5), the first rigid plate (5) and the centers of the corresponding actuators (9) and attached to the second rigid plate (6) being pierced at these said mechanical connection means (12).

11 - deformable mirror (1) according to the preceding claim, characterized in that the lower connecting means (23) consists of a layer of adhesive material applied in a hole drilled in the second rigid plate (6) to a configurable depth in advance.

12 - deformable mirror (1) according to at least one of claims 3 to 11, characterized in that at least one flexible coupling means (12) comprises between the mechanical connection means (21) and the lower connection means ( 23) an adjustable room.

13 - deformable mirror (1) according to at least one of the preceding claims, characterized in that each lower connecting means (23) is a rigid connection means consisting of an adhesive material having a polymerization time greater than one minute and each upper link means (22) is a flexible linkage means made of an elastomeric adhesive material.

14 - deformable mirror (1) according to at least one of claims 1 to 12, characterized in that each lower connection means (23) is a flexible connection means consisting of an elastomeric adhesive material, and each upper connecting means (22) is a rigid bonding means consisting of an adhesive material having a polymerization time greater than one minute.

15 - deformable mirror (1) according to at least one of claims 1 to 12, characterized in that each lower connecting means (23) is a flexible connecting means consisting of an adhesive material per elastomer, and each means of upper link (22) is constituted by the adhesive layer (11) in which at least one of the mechanical connection means (21,21 ') is able to penetrate.

16 - deformable mirror (1) according to at least one of claims 1 to 12, characterized in that each of the lower connecting means (23) and upper (22) is a flexible connecting means consisting of an adhesive material by elastomer.

17 - Tool for producing a deformable mirror (1) according to at least one of the preceding claims, further comprising: a lighting device (30) for producing a parallel light beam; a wavefront sensor (31);

a computer (34) capable of receiving data transmitted by the wavefront sensor (32) and the setpoint device (33);

a control box (35) in connection with said computer and able to separately control each actuator of the deformable mirror (1) in order to control the local deformation associated with each actuator of said deformable mirror

(I) -

18 - Process for pre-forming a deformable mirror (1) according to at least one of claims 1 to 14, with the aid of an embodiment tool according to the preceding claim, comprising successively the following steps: the adhesive layer (11) is fixed to the deformable membrane (2);

- The upper connecting means (22) is attached to the adhesive layer the upper end (13) of each flexible coupling means (12) is coupled to the adhesive layer (11) via the upper connecting means (22); the lower end (14) of each flexible casting means (12) is attached to at least one of the rigid plates (5, 6) via the rigid lower connection means (23), said rigid lower link means ( 23) being made of an adhesive material having a polymerization time greater than one minute; during the polymerization of the adhesive material constituting the rigid lower connection means, a closed loop controls and optimizes the restoring forces of the actuators of the deformable mirror so as to pre-form the membrane of the mirror in a predetermined shape, for the duration of the said polymerization.