Abstract:
The invention relates to a method for at least partially deconstructing a flat display screen ( 10 ), the screen ( 10 ) comprising: —a substantially flat faceplate ( 11 ) comprising four side edges and a visible part ( 12 ) on a front face of the screen ( 10 ), said visible part ( 12 ) being intended to display images, —a frame ( 13 ) that mounts the faceplate ( 11 ) by partially covering at least the front face and two side edges, the method comprising steps of: —disposing ( 100 ) a single screen ( 10 ) on a holding device ( 20 ), and —clamping ( 110 ) the single screen ( 10 ) to the holding device ( 20 ). The method is essentially characterized in that it also comprises a step of: —effecting plastic deformation ( 120 ) of the frame ( 13 ) while maintaining the integrity of the faceplate ( 11 ).

Description:
TECHNICAL FIELD 
     The present invention relates to the deconstruction that is to say the dismantling of flat screens. 
     BACKGROUND 
     It applies to any types of screen, whether it be screens with a liquid crystal panel (LCD Liquid Crystal Display) and backlight lamps (CCFL, LED or other) or other types of displays, such as: 
     Plasma 
     OLED (organic light emitting diode) 
     SED (Surface-conduction Electron-emitter Display) 
     FED (Field Emission Display) 
     OEL (Organic Electroluminescent) 
     PLED (polymer light-emitting diodes) 
     PHOLED (Phosphorescent Organic Light-Emitting Diode) 
     In order to destroy or decontaminate these flat screens at the end of life, there are industrial methods of at least partially grinding these screens during which the faceplate and/or the backlight lamps are usually destroyed or partially damaged. Hence, such methods can cause the release of gases and toxic substances, such as mercury, for example, in the air, on the ground, or in direct contact with constituents of the screen that are liable to be recycled. However, the mercury that is released tends to pollute the other screen members, such as plastic which becomes difficult to recycle. These methods are hence responsible for some pollution and substantially increase the difficulty of recovering any recoverable components, particularly liquid crystals, and metals, particularly indium from the screen. 
     At present, the existing solutions consist in crushing the screen and drawing out the toxic gaseous elements, or dismantling the screen entirely manually, which is not satisfactory in terms of environmental protection, and in terms of productivity. 
     BRIEF SUMMARY 
     The purpose of the present invention is to overcome these drawbacks by proposing a solution aiming to preserve the integrity of the faceplate of a flat screen as much as possible. 
     More specifically, the invention relates to a method of deconstructing at least partially a flat display screen, the screen comprising: 
     a substantially plane faceplate, comprising four lateral edges and an visible portion on a front side of the screen intended for image display, and 
     a frame, mounting the faceplate by partially covering at least the front side and two lateral edges, 
     the method comprising steps including: 
     placing a single screen on a holding device, and 
     clamping the single screen on the holding device. 
     According to the invention, the method is substantially characterized in that it further comprises a step including: 
     carrying out a plastic deformation of the frame, while maintaining the integrity of the faceplate. 
     Thanks to this characteristic, it is possible to avoid cutting the frame. This makes it possible to open the screen while avoiding aggressive industrial techniques and which generate waste (in particular non-recoverable). In particular, cutting leads to: 
     many vibrations in the screen (which can lead to the damage of fragile members such as mercury lamps) 
     generates a lot of dust, gas and chips, and 
     induces consumables (a cutting tool has a limited life). 
     In one embodiment, the method further comprises a step of weakening of the frame by mechanical action and/or heat on the frame. 
     Thus allowing to limit the forces to be applied for deforming the frame. 
     Preferably, the weakening step is only implemented on all or part of the portion of the frame which partially covers the front side of the screen. 
     In one embodiment, at least two out of the four corners of the screen are clamped, the plastic deformation being performed on an unclamped corner. 
     In one embodiment, the method further comprises a step of determining the dimensions and the position in space of the visible faceplate. 
     This then allows to subject the efforts to be applied to the determined dimensions. 
     In one embodiment, the method further comprises a step of laser profilometry including obtaining the three-dimensional topography of at least one portion of the screen. 
     Thus allowing for an optical tracking of the screen, that is to say, a shape analysis thereof. 
     In one embodiment, the method further comprises a step comprising removing the faceplate from the frame. 
     The invention further relates to a device for holding a flat display screen for at least its partial deconstruction, the device comprising: 
     a clamping system comprising: 
     a support, whereon a screen is likely to be positioned, 
     a set of independent branches mounted on the support, 
     a flange positioned at the end of each branch. 
     Preferably, each flange is rotatably mounted with respect to the branch which supports it, according to an axis of rotation perpendicular to the plane of the support, and/or each branch is mounted in rotation with respect to the support, according to an axis of rotation perpendicular to the plane of the support. 
     Advantageously, each branch is telescopic. 
     The invention is advantageously compatible with all screens, whatever their status (new or used), size (dimensions of the faceplate), their weight and their material(s) of manufacture. 
     The invention also relates to a system for at least the partial deconstruction of a flat display screen, the system comprising 
     a holding device according to the invention, 
     possibly a screen positioned in the holding device, and 
     a plastic deformation device liable to be set in relative motion with respect to the screen such as to exert a mechanical force on the frame in order to deform it according to at least one of the following trajectories: a rectilinear trajectory parallel with the plane of the faceplate, a rectilinear trajectory non parallel with the plane of the faceplate, a curved trajectory, or a combination of these movements. 
     Preferably, the plastic deformation device comprises 
     a knife and 
     possibly a rotating force transmission means, connected to the knife, 
     the knife comprising a form making it possible to concentrate the constraints to be applied to the frame. 
     Advantageously, the knife exhibits a leading edge that is configured to switch between the faceplate and the frame. 
     The knife may have a leading edge exhibiting a variable opening angle on the depth of the knife. 
     It can also be provided a camera to view on the console of an operator the proceedings of the application of the plastic deformation forces. 
     Thanks to the invention, it is possible to move aside at least one side of a screen by deforming the frame thereof, this makes it possible to remove the faceplate and any possible filters/diffusers, as well as give access to any possible backlight lamps. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Other characteristics and advantages of the present invention will become apparent upon reading the following description given by way of illustrative and non-limiting example and with reference to the accompanying drawings in which: 
         FIG. 1  illustrates one embodiment of the method according to the invention, wherein the optional steps are in dotted lines, 
         FIG. 2A  illustrates a front view of a flat screen, 
         FIG. 2B  illustrates a front view of a flat screen with circular areas illustrating preferential areas of weakness of the frame, 
         FIG. 3  illustrates a flat screen maintained in an embodiment of a holding device according to the invention, in a three-quarter view, 
         FIG. 4A  illustrates one embodiment of a knife according to the invention in top view, 
         FIG. 4A ′ illustrates the knife of  FIG. 4A  in side view, 
         FIG. 4B  illustrates an embodiment of a knife according to the invention in three-quarter view, 
         FIG. 4B ′ illustrates the knife of  FIG. 4B  in side view, 
         FIG. 4C  illustrates one embodiment of a knife according to the invention in top view, 
         FIG. 4C ′ illustrates the knife of  FIG. 4C  in three-quarter view, 
         FIGS. 5A to 5D  illustrate in top view, by full arrows, the different knife movements for the deformation of the frame of a screen with a knife ( FIG. 5C ), two knives ( FIG. 5B ), three knives ( FIG. 5D ), and four knives ( FIG. 5A ), 
         FIGS. 6A to 6D  illustrate in transversal cross-section by full arrows, different movements of translation and/or rotation for a knife, applied on the frame, the casing not being represented, 
         FIG. 7  illustrates in transversal cross section the result of plastic deformation by a knife on the frame of a flat screen, wherein the casing is not represented, 
         FIG. 8  illustrates in substantially top view the clamping of a screen in an embodiment of a holding device according to the invention, wherein the flanges do not cover the faceplate, the dots illustrating the limits of the faceplate concealed by the casing, 
         FIG. 9  illustrates an embodiment of a holding device according to the invention, 
         FIG. 10  illustrates by full arrows the possible movements of translation and rotation for an arm of an embodiment of a holding device according to the invention, and 
         FIG. 11  illustrates the holding of a screen on a support according to another embodiment of a holding device according to the invention. 
     
    
    
     DETAILED DESCRIPTION 
     These days, there are flat screens in many fields: computer monitors, televisions, tablet PCs, navigation devices, etc. For environmental reasons, it is desirable that all flat screens be deconstructed at the end of life, in order to make the treatment of their components possible, particularly their recovery. 
     All flat panel screens include a faceplate, which allows for the display on the front side of the screen. 
     By faceplate  11  or matrix, is meant the generally rectangular portion of a flat screen  10  whereon the image is formed. For an LCD screen  10 , the polluting elements are the liquid crystals enclosed between two fine glass plates and which allow for the formation of the image. 
     Certain flat screens comprise backlight lamps, placed behind the faceplate  11  with respect to the display. Some lamps may also contain polluting elements (for example, mercury). 
     The faceplate  11  is contained in a frame  13 . 
     The frame  13  is generally made of metal and has a function of maintaining the constitutive members of the screen, particularly the faceplate. 
     The faceplate  11  and the frame  13  are housed in a casing  14 . 
     The casing  14  is generally made of plastic, of globally parallelepiped shape and has a generally aesthetic function of concealing the structural members such as the frame  13  and/or the possible seals, connectors, etc. which would otherwise be apparent. It also covers the rear side of the screen. 
     The mechanical resistance of the frame  13  being greater than that of the casing  14 , the plastic deformation aimed for here relates to that of the frame, any plastic deformation of the frame  13  causing that of the casing  14 . 
     The casing  14  has a substantially rectangular opening (window) whereof the dimensions are slightly lower than the dimensions of the surface of the faceplate, such that the faceplate  11  has a visible portion, called “visible faceplate  12 ” ( FIG. 2A ), and a portion concealed under the casing. The casing  14  encloses the faceplate  11  by securely covering the edges thereof. 
     For the treatment of flat screens, with a view to their recovery, it is important to maintain the integrity at least of the faceplate, and possibly of the backlight lamps. Integrity is considered to be kept as long as the damage subjected to a screen  10  does not allow the release of polluting elements. In this vein, it can be considered for example that the faceplate  11  may be scratched. 
     The advantage of keeping the integrity is that the pollutant suction devices can be used only by way of precaution in the event of an accident for example, and not for every dismantling of each screen  10  as in the prior art. 
     Method 
     It can be provided a preliminary step of preparing the screen  10 , comprising removing the possible stand of the screen, removing possible cables or aesthetic elements (stickers, etc.). 
     It is provided a step  100  comprising arranging a single screen  10  on a holding device, preferably the visible faceplate  12  towards the top, that is to say, directly accessible to an operator or a robot. The holding device  20  has for function to maintain the screen  10  whatever the operations to be carried out on the screen. In particular, it comprises flanges  23  capable of withstanding mechanical tension. Therefore, the screen  10  and the holding device  20  become integral for the deconstruction of the screen after clamping  110 . 
     The holding device  20  comprises at least two flanges  23 A,  23 B,  23 C,  23 D, each flange preferably being taken on a respective corner of the screen. For each corner, it is sufficient to tighten the screen  10  for example from the top (front side of the screen), from below (rear side of the screen) and from both sides (lateral sides of the screen) of the corner in order to maintain it. In this case, the screen  10  is maintained stationary with at least two flanges arranged on two opposite corners (diagonally on the screen). 
     In operation, for a better hold of the screen, three out of the four corners of the screen can be clamped. Consequently, plastic deformation actions can be carried out on the fourth corner (unclamped) without risk of damaging the flange. 
     It is provided a step  140  of determining the dimensions and position of the visible faceplate  12 . This makes it possible to define the straight lines (in three dimensions in a given reference), each corresponding to the intersection between the inner edges of the casing  14  and the plane of the faceplate, such as to correctly position the knives in a later step. 
     To this end, a possibility is offered by the holding device  20  itself: for example, the measured spacing of the flanges holding the screen  10  provides information about the height or the outer width of the screen. Thus, making it possible to roughly locate the corners of the screen. One can further position a camera  50  over one of the corners. 
     Laser Profilometry 
     Another possibility is offered by laser profilometry  150  of the screen. 
     Laser profilometry concerns obtaining the (three-dimensional) topography of one portion at least of the screen. A laser projects a plane beam resulting in a line of light on an area of the screen. The laser is inclined at a given angle, for example 30° to 45°, with respect to the optical axis of a camera (possibly the same camera  50 ) which scans an area where the laser line is projected and reflected in the direction of the camera such as to image the deformations of the line due to the relief, that is to say, the geometry of the screen  10  (casing, buttons, etc.). Preferably, the optical axis of the camera or the laser plane is orthogonal to the faceplate. 
     The movement of the camera is integral with the laser movement, for example by both being carried by a robotic arm (not illustrated). This arm makes it possible to produce a movement of translation (scanning) of the camera-laser assembly particularly parallel to the faceplate. 
     The observation by the camera of the deformed laser line makes it possible, thanks to a prior calibration of the camera-laser system and the implementation of an image processing algorithm well known in the field, to know the 3D coordinates in a coordinate system (for example that of the robot) of each point of relief of the screen having been scanned by the camera-laser assembly. 
     Advantageously, it is not necessary to recreate a complete representation of the relief of the screen, but only to have knowledge of at least the coordinates of certain characteristic points. 
     The laser line can be scanned (automatically) on the four sides of the screen, such as to determine the characteristic points corresponding to the transition points between the faceplate  11  and the casing  14  of the screen, that is to say such as to define the contour (perimeter) of the visible faceplate  12 . 
     This step of laser profilometry  150  makes it possible to locate the surface of the faceplate in space with respect to a given reference and also to check the state of flatness and possible degradation of the surface of the faceplate  11 , and emit an alarm or remove a screen  10  from the deconstruction circuit if need be. 
     Weakening 
     For the plastic deformation  120  of the frame, significant mechanical forces are exerted thereon. However, the constraints are mainly focused on the corners of the frame. Therefore, it can be provided a step  130  comprising weakening the frame  13 , particularly the corners thereof. 
     The step of weakening makes it possible to reduce mechanical resistance upon plastic deformation of the frame, that is to say of the material(s) composing it or the junction between these materials in a corner of the frame. Hence, it makes it possible to decrease the mechanical forces required to plastically deform the frame  13 —hence of the opening of the screen  10 —and makes it possible to promote a possible breakage of the frame  13  on the weakened areas. 
     This weakening  130  can be achieved by removing material, modifying the form or physical properties of the frame. Several solutions are possible. 
     by mechanical action: 
     it may be provided a machining of the frame, particularly of the corners, using an abrasive tool (grindstone, cutter, drill). It may also be provided a partial cut of the frame, particularly the corners, with a cutting tool (circular saw, cutting tool, . . . ) 
     by thermal action: 
     it may be provided cryogenic treatment of the frame  13  to make it more breakable, or 
     the heating of the frame  13  to reduce its mechanical strength. 
     It can be provided to drill the corners of the frame  13  covering the faceplate ( FIG. 2B ), without damaging the faceplate  11 . The drilling may be on all or part of the thickness of the frame  13  covering the faceplate. 
     It can be provided that the weakening step  130  precedes the plastic deformation step  120 . 
     It can be provided that the weakening step  130  and plastic deformation step  120  be simultaneous, also for example, thanks to the shape of a tool  30  described later. 
     The weakening step  130  makes it possible to deform, cleave, split, crack, or break the frame. 
     The mechanical forces to be applied (force and/or torque) for the plastic deformation of the frame, serve to release the faceplate  11  from the frame  13  which maintains it. Hence, it is possible to only weaken the frame  13  on the part covering the faceplate  11  (front side of the screen), particularly in the corners. 
     For the plastic deformation of the frame, the mechanical forces are applied by a plastic deformation device. 
     Plastic Deformation Device 
     The plastic deformation device comprises a knife  30  connected to a means  40  for transmitting a force, for example a jack, possibly rotatable. 
     By knife, also known as a wedge is meant an instrument or oblique-sided mechanical piece of essentially prismatic shape whereof two main sides, in this case a leading edge  31 , or ridge, intersect at a sharp angle. Unlike cutting tools that require sharpening, the knife  30  is a tool of force concentration. Furthermore, the implementation of the knife  30  aims to deform the frame, possibly until it breaks. It is thus not only distinguished from cutting techniques but further by degree of precision that they require. 
     The shape of the knife  30  ( FIGS. 4A, 4A ′,  4 B,  4 B′,  4 C,  4 C′) makes it possible to focus the constraints transmitted by the jack on the leading edge  31 , which serves to concentrate the mechanical forces. Preferably, the shape of the leading edge  31  is rectilinear and substantially perpendicular to the plane of the faceplate or has a sharp angle ranging between 45 and 90° with respect to the plane of the faceplate ( FIGS. 4A ′,  4 C′). 
     In one embodiment that is non-illustrated, the knife  30  comprises along its entire length a rectilinear groove extending along an axis of elongation parallel to the plane of the screen and the frame, that is to say, orthogonal to the travelling direction of the knife, such that the frame can be inserted in said groove and be in abutment with the edges thereof during the pushing movement of the knife, thereby constraining the elastic or plastic deformation of the frame. 
     The leading edge  31  can be configured to switch between the faceplate  11  and the frame  13  (particular  FIGS. 4B, 4B ′). It makes it possible for example to be put in contact with the frame  13  during the initial positioning (see below), and remain in contact with the frame  13  when applying force. It makes it possible to exert a spacing and distorting function of the frame  13  with respect to the faceplate  11 . 
     The leading edge  31  may be, in combination ( FIGS. 4A ′,  4 C′) or alternatively configured to pass between two adjacent sides of the frame, that is to say to concentrate the mechanical forces in a corner thereof. 
     The leading edge  31  may have a weak opening angle (less than 45°) and be extended by a thicker part (whereof the opening angle is larger. This shape makes it possible to lift the frame  13  (upon applying a mechanical force parallel with the plane of the faceplate) and lock the frame  13  on the knife, enabling a better thrust during the movements thereof. The angle of incidence  31  may vary switching for example from 25° on the drive line  31  to 50° after a few millimeters. The portion in contact with the faceplate  11  is flat, such as to slide more easily on the faceplate without causing jamming or damage to the integrity of the faceplate. 
     The knife  30  can have several forms: 
     a flat effective area, practical during the spacing of the flat portions of the frame ( FIGS. 4B, 4B ′), 
     a flat effective area with a sharp corner ( FIGS. 4A ′,  4 C′) or in curved or rounded form (not represented) practical during the spacing of the corners of the frame, 
     an area with several geometries (flat and/or sharp and/or curved corner . . . ), to be taken from any location of the frame  13  (form not represented). 
     Depending on the form of the knife  30 , the weakening step  130  and the plastic deformation step  120  can be implemented not only simultaneously but further with a single tool, in this instance the plastic deformation device comprising the knife  30 . For example, as illustrated in  FIG. 4C ′, the leading edge  31  non parallel with the plane of the faceplate makes it possible to weaken the frame by focusing forces. The two main sides, that is to say the flanks on either side of this leading edge  31  make it possible to plastically deform the frame during the relative movement between the knife  30  and the frame. 
     Initial Position 
     Before applying the mechanical forces required for the plastic deformation of the screen, the plastic deformation device is manually and/or automatically placed in initial position, by a relative movement between the latter and the screen  10  (the screen  10  being preferably maintained). 
     Preferably, in the initial position, the plastic deformation device is in contact with the frame  13  or the casing  14  of the screen. 
     Plastic Deformation 
     Once placed in the initial position, the plastic deformation device is brought in relative movement with respect to the screen  10  such as to exert a mechanical force (force and/or torque) on the frame  13  to deform it ( FIG. 5A to 5D ). 
     The relative movement may be implemented according to at least one of the following trajectories: a rectilinear trajectory parallel with the plane of the faceplate ( FIG. 6A ), a rectilinear trajectory non parallel with the plane of the faceplate ( FIG. 6B ), a curved trajectory ( FIG. 6C ) or a combination of these movements ( FIG. 6D ). 
     A curved trajectory allows for example to raise the portion of the frame  13  covering the front side of the faceplate  11  with a rotational movement of the knife  30  with respect to an axis of rotation parallel to the side of the screen  10  whereon the plastic deformation is implemented ( FIG. 7 ). 
     The plastic deformation of the frame  13  makes it possible to deform the frame hence, to release the faceplate  11  from the screen. The deformation is relative and even proportional with the force applied by the knife  30  connected to a force transmission means  40 . It can be provided that the plastic deformation will cause to the mechanical rupture of the frame. 
     The plastic deformation is not a cutout from the frame. Advantageously, the knife  30 , even from metal does not need to be particularly sharp. And compared to the cutout solutions requiring precision and special mastery, the present solution is easier to implement and less costly since the knife  30  is not a consumable item as is a saw blade for example. 
     It is worth noting that during deformation, one or several knives (identical or not) can be used on a same screen simultaneously or sequentially. The relative movements of each knife  30  may be independent: each knife  30  can have a similar or different movement to/from one another. 
     Typically, after the measurements of the dimensions of the position of the screen  10  by laser profilometry  150 , a computer algorithm determines the trajectories (movement) of each knife  30  (direction, way, angle of rotation, starting point and the point of arrival of the movement of the knife by means of the jack  40 ). 
     In accordance with the determined trajectories, a robot then manipulates the knife or knives, which has for effect to open the frame  13  of the screen  10  by plastic deformation of the frame. 
     For example, the knife  30  carries out a translation of a few centimeters in the plane of the faceplate, then a rotation of 90° around the axis parallel to the edge of the screen  10  whereon the knife  30  is performing the deformation, such as to raise the edge, which is hence no longer above the faceplate. 
     The same operation can be carried out over the entire length of the frame, so that a whole side of the frame  13  be entirely open. The same operation can be performed on each side of the frame. 
     The flange system of the holding device  20  can be applied at any point that is not on the trajectory of the knife. 
     Check 
     It can be provided at least a camera (for example the camera  50 ) to view and/or control on the console of an operator the proceedings of the application of the plastic deformation forces. The operator may then validate the step of plastic deformation or invalidate it, for example via a push button. 
     In case of validation that is to say when the frame  13  has been sufficiently open to be able to remove the faceplate, the faceplate  11  may then be removed  160  from the frame. 
     In case of invalidation, a new sequence of deformation can be applied, for example by modifying the parameters representative of force, or the stroke length of the knife. 
     Holding Device 
     The holding device  20  comprises at least one flange  23 . 
     The flange  23  is taken on one side of the screen, preferably by remaining as far as possible from the visible faceplate  11  ( FIG. 8 ). It can also be taken behind and/or in front, as long as it does not hinder the execution of the method. 
     The flange  23  can be fixed on a stationary support (for example a table) and/or a mobile system able to move (for example a robot). 
     In the case where the flange  23  and hence the screen  10  held therein, is mounted on a mobile system, the position of the flange in space is always known. Thereby, the position of the screen  10  in space is also known. 
     For the flange, it can be provided a mechanical clamping system, a suction system, a magnetic system, a system based on adhesive material, or a combination of these possibilities. 
     In one embodiment ( FIG. 11 ), the holding device  20  comprises a set of plates  24  (drilled at each end) and screws, each set of plates and screws acting as flanges. 
     The screen  10  is maintained by two or three plates  24  each screwed to a corner of the screen  10  on a special table, of machining table type (that is to say, with special mobile notches to place and tighten the screws so that they be stationary through tightening) at multiple points ( FIG. 11 ). 
     The dimensions of the plates are preferably selected such that they press on the screen  10  without covering the visible faceplate  12  and preferably without also covering the faceplate  11  concealed under the casing. 
     Preferably, the screws crossing each plate are in contact with the screen. 
     In an embodiment ( FIG. 3 ), the screen  10  is maintained by a (possibly automatic) clamping system. 
     An embodiment of the clamping system is illustrated in  FIG. 9 , maintaining a screen  10  in the latter being illustrated in  FIG. 3 . 
     The clamping system comprises:
         a support  21  able to be mounted on a mobile tool (for example a robot),   a set of branches  22 A,  22 B,  22 C,  22 D independent from each other and mounted on the support  21 , typically three or four branches. Preferably, each branch is mounted in rotation with respect to the support, according to an axis of rotation perpendicular to the plane of the support. Preferably, each branch is telescopic in order to be able to modify its length ( FIG. 10 ),   a flange  23 A,  23 B,  23 C,  23 D positioned at the end of each branch. Preferably, in order to be able to orient it, each flange is mounted in rotation with respect to the branch which supports it, according to an axis of rotation perpendicular to the plane of the support. Each flange comprises two plates  24  mobile with respect to each other thanks to two screws. The tightening of the flange is carried out for example thanks to a relative rectilinear movement of the two plates with respect to one another.
           It can be provided that each flange  23  (set plate+screw) is adjustable in height with respect to the respective branch  22  which supports it, for example by means of a helical connection between the flange  23  and the branch  22  of a sliding pivot joint lockable in translation by means of a stop pin in translation of the flange  23  with respect to the branch  22  which supports it. This last feature allows for the clamping device to be able to receive and clamp any type of screen, regardless of its length, width, or depth.   
               

     In order to maintain a  10  screen with such a holding device, it is provided on a given arm:
         First, the arm is moved away, for example by extending it to a maximum,   The screen  10  is positioned on the support, faceplate  11  upwards,   The arm undergoes a rotation in order to be parallel to a diagonal of the screen,   The arm is retracted, such that the screws of the flanges are pressed on a corner, thanks to a rotation of the flange,   The clamp is tightened, thereby blocking the screen  10  by the corner.   Such a holding device  20  can be adapted to all screen sizes.       

     Once the screen  10  is clamped, the step of laser profilometry  150  can be for example implemented. 
     Withdrawal of the Faceplate 
     Once the plastic deformation carried out, the faceplate  11  is no longer maintained by the frame. The flange may be removed. 
     The withdrawal operation  160  may be performed by an operator and/or an automated mobile system (robot). 
     The only remaining links between the faceplate  11  and the rest of the screen  10  are usually flexible electronic cards and/or cables. These various links can be cut or broken, including during the removal of the faceplate, thanks to a fairly rapid movement and/or with enough force. 
     During this action, little or no force is applied on the members placed behind the faceplate  11 : filters and diffusers, possible backlight lamps, electronic cards, etc. Thus, making it possible to maintain their integrity. 
     The faceplate  11  can be removed from the frame  13  in several ways:
         the faceplate  11  is drawn along a trajectory comprising an initial movement in a direction substantially perpendicular to the plane of the frame  13  (before deformation), for example by suction cups,   the faceplate  11  can be removed by sliding it along the screen  10 , like a sheet of paper being removed from an envelope,   the faceplate  11  can be lifted by a lever, thanks to a lever tool such as a screwdriver, spatula, etc. Once lifted, the faceplate  11  can be manipulated manually or by an automated system with a gripping tool that is non-aggressive for the faceplate  11 : suction cup, pliers, venturi effect, . . .   the screen can be turned around to remove the faceplate  11  by gravity.       

     For example, an operator places a flat tool (of screwdriver type) between the faceplate  11  and the deformed frame  13 . The operator brings the flat part of the tool under the faceplate  11  and by leverage effect, lifts the faceplate. Thus, he can without moving the screwdriver in his hand, grab the faceplate  11  with the other hand and remove it. The frame  13  having been deformed such that the opening created by the deformation be greater than the faceplate, this operation is simple to implement and does not pose any particular risk for the faceplate, the operator or the other members of the screen. 
     The faceplate  11  having been withdrawn, the operator can, in the same manner, remove the filters and diffusers under the faceplate. 
     Once the faceplate  11  removed, the rest of the screen  10  may undergo another deconstruction treatment. In particular, the screen  10  may undergo a method of removing the backlight lamps.