Abstract:
A screen device ( 10 ) having a casing ( 10 ), a projection screen ( 12 ) and a setting ( 13 ) associated with displacement mechanism ( 20 ) for modifying the visible content of the casing. The projection screen ( 12 ) and the setting ( 13 ) are combined on a unitary support sheet ( 14 ) and the displacement mechanism ( 20 ) comprise two parallel winding rollers ( 21, 22 ) about which the support sheet ( 14 ) is wound, and one of the rollers is a driven roller. Stiffening mechanism ( 50 ) is associated with the two free edges ( 14   a ) of the support sheet ( 14 ) for stiffening the free edges in the winding direction of the and to confer a perfect flatness to the sheet over its entire surface area. A guide mechanism ( 60 ) is associated with the stiffening mechanism ( 50 ) for the free edges ( 14   a ) of the support sheet ( 14 ).

Description:
This application is a National Stage completion of PCT/FR2013/000115 filed Apr. 25, 2013, which claims priority from French patent application serial no. 12/53923 filed Apr. 27, 2012. 
     FIELD OF THE INVENTION 
     The present invention relates to a retractable projection screen device including at least one projection screen and at least one setting superimposed on said projection screen in at least one retracted position of said screen, and displacement means associated respectively with said projection screen and/or with said setting to move at least one of said projection screen or said setting with respect to the other in order to make said projection screen visible in at least one position of use of said screen, said at least one projection screen being carried by a support sheet and said displacement means including at least two parallel winding rollers whereon said support sheet winds up, at least one of said rollers being a motorized driving roller. 
     BACKGROUND OF THE INVENTION 
     The home cinema devices allow viewing a movie, a television program, Internet contents, a photo album, etc., using a video projector, on a more or less large screen, depending on the space available. This projection screen is generally mounted on a wall and occupies a large space that prohibits installing any other setting in the place of this screen. When it is not used as a projection screen, it shows a white surface, surrounded or not by a black frame, which is neither aesthetic nor pleasant to the eye in a living room. This is why some users install a cinema room in their house, intended exclusively for movie projection. However, these constraints limit the development possibilities of home cinema and hold back in particular potential users who have no specific room to dedicate to cinema. 
     Roll-down screens as described in publication WO 2004/027515 are known, housed or not in a casing mounted on a wall, and which are unwound on request to make a projection. This solution is not satisfactory, both in terms of picture quality, since the screen is not stretched laterally and distorts the picture, and in terms of practicality and aesthetics in a living room. 
     Other solutions exist to hide a projection screen on the rear side of a piece of art, a picture or any other wall setting, in order to have a discrete projection screen in a living room and to be able to convert this living room at will in a cinema room. An example is described in publication FR 2 879 766. It discloses a picture having on its back a casing containing a device with articulated arms that opens in three parts as a triptych to unfold and stretch a projection screen carried by said device, the picture being one of the sections of the triptych. This solution is not satisfactory as the fabric is folded in its retracted position, the mechanism is complex and cumbersome on the back of the picture, which in most cases imposes letting said casing into the wall, entailing additional work and expenses. Moreover, this solution is restricted to one screen size and one screen type, and does not allow considering different screen sizes according to the format of the projection, neither different reflective qualities for the screen. 
     Publication CN 2 837 102 Y discloses a more user-friendly solution wherein a picture includes at least one fabric wound between two parallel rollers and showing, according to its position, a decorative picture, a projection screen, or a writing board. However, this fabric cannot provide a projected image of high quality as its free ends are floating, not held and can generate distortions of the projected image. 
     Publication US 2007/0285337 A1 discloses a foldable or windable screen whose free edges are stiffened by means of self-supporting strips that are obligatorily curved and housed in slides added along said free screen edges, allowing the self-support of the screen in normal position of use and maintaining its flatness. However, the implementation of this solution is complex, costly and not reliable. The addition of the slides leads to extra manufacturing costs and to excess thicknesses in the free edges of the screen that can be prejudicial both to the size and to the integrity of the screen when it is wound on itself. Moreover, this solution cannot be transposed to a support sheet that circulates between two rollers as nothing is provided to prevent the fabric from shifting transversally with respect to the rollers. 
     SUMMARY OF THE INVENTION 
     The present invention aims to overcome the disadvantages mentioned above by offering a simple, reliable, cost-effective mechanical device with a reduced depth, that allows hiding a projection screen on the rear of a piece of art, a picture or similar, able to keep the projection screen stretched both in its horizontal and vertical directions, without folds, both in its different positions and during its movement, this device giving also the possibility to provide for several screen sizes and/or several interchangeable wall settings and/or several reflective qualities of the screen. 
     To that purpose, the invention relates to a screen device of the type stated in the preamble, characterized in that it includes moreover stiffening means associated to the two free edges of said support sheet to stiffen them at least in the winding direction of said support sheet and confer to said support sheet a perfect flatness over its entire surface and in that it also includes guide means arranged to guide the free edges of said support sheet associated with said stiffening means, 
     In a preferred embodiment, said stiffening means include at least one strap, for example made out of metal, added on the free edges of said support sheet, said strap being rigid in its length along its longitudinal axis X and in its width along its transversal axis Y, and being flexible in its thickness so as to allow winding it on itself with said support sheet. This strap is partly fitted onto the free edges of the support sheet so that said strap has a free inside edge and a free outside edge. The free edge of said support sheet can coincide with the free outside edge of said strap. 
     In the preferred embodiment, the guide means include longitudinal grooves arranged to receive by sliding at least the free inside edges of the straps, these longitudinal grooves being carried by at least one support. 
     Said longitudinal grooves can be arranged in guides placed on said support to ensure the guidance of at least the visible section of the support sheet or to ensure the guidance of both the visible section and the retracted section of the support sheet. 
     If the guides are arranged on either side of said support, they can be connected two by two by means of an elastic tape arranged to balance the tension between the visible section of the support sheet and the retracted section of the support sheet, and self-center said support sheet. 
     The guides can also be mounted movably on supports and tensioned by return means in order to stretch said support sheet. 
     Said displacement means can include two winding rollers of which at least one is a motorized driving roller and said support sheet can form a closed loop around said winding rollers. 
     They can also include at least two winding rollers and two driving rollers, and said support sheet can then form an open loop wherein each of its ends winds up on one of the driving rollers, 
     In this embodiment variant, said support sheet can include several projection screens with different sizes and/or different reflective qualities and/or several setting types placed one after the other. 
     In the preferred embodiment, the screen device includes a casing arranged to be hung on a wall or carried by a carrier structure, and to contain said displacement means and said support sheet. This casing can be specific of made of a recess arranged in said wall. 
     In an embodiment variant, said casing can be telescopic and include at least one bottom panel and two end panels carrying at least said winding rollers and said driving rollers, said end panels being slidably mounted with respect to said bottom panel so as to be able to move away from each other and increase the center distance of said winding rollers, as well as the dimension of the visible section of said support sheet. 
     According to the required dimensions, said casing can include at least one additional stage made of at least two intermediate panels located between said bottom panel and said end panels and slidably mounted with respect to each other. 
     In this case, at least said end panels are tensioned towards their opened position by return means that tend to move them away from each other and they are held in closed position by motors coupled to said driving rollers. 
     The supports of said guide means can be mounted on slides so as to follow the free edges of said support sheet during the opening and closing displacements of said telescopic casing. 
     The casing of said retractable screen device, whether telescopic or not, can advantageously include loudspeakers behind said support sheet, which can include micro-perforations at least in front of the loudspeakers to further sound diffusion. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The present invention and its advantages will be better revealed in the following description of several embodiments given as non limiting examples, in reference to the drawings in appendix, in which: 
         FIG. 1  is a front view of the projection screen device according to a first variant of the invention wherein the casing is fixed, the projection screen being visible and the cower frame being removed to show the inside of the device, 
         FIG. 2  is a front view of the device of  FIG. 1  at a reduced scale, the wall setting being visible and the cover frame being mounted, 
         FIG. 3  is a schematic top view of the displacement means for moving the sheet carrying the projection screen and the wall setting of the device of  FIGS. 1 and 2 , 
         FIG. 4  is a view similar to  FIG. 3  of an embodiment variant of the displacement means of  FIG. 3 , 
         FIG. 5  is a view similar to  FIG. 3  of another embodiment variant of he displacement means, which allow unwinding several projection screens, 
         FIG. 6  is a partial perspective view showing a sheet driving roller carrying the projection screen and the wall setting, its stiffening means and its guide means, 
         FIG. 7  is a partial end view of the stiffening means and of the guide means of  FIG. 6 , 
         FIG. 8  is a perspective view of an embodiment variant of the guide means of  FIG. 6 , 
         FIGS. 9A, 9B and 9C  are front views of the projection screen device according to a second variant of the invention, wherein the casing is telescopic and represented respectively in closed position and in open position, offering two screen sizes, 
         FIGS. 10A and 10B  are schematic top views of a first embodiment of the displacement means of the device of  FIGS. 9A to 9C , respectively in closed position and in open position, 
         FIGS. 11A and 11B  are rear views of a second embodiment of the displacement means of the device of  FIGS. 9A to 9C , respectively in closed position and in open position, in partial perspective views, and 
         FIG. 12  is a perspective view of a guide means of the screen of the device of  FIGS. 11A and 11B . 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring to  FIGS. 1 to 8 , the retractable projection screen  10  according to the invention includes at least one casing  11  arranged to be hung on a wall  1 , on a carrier structure or similar. In the represented example, this casing  11  is rectangular and the wall  1  is a wail or a partition wall. Of course, this casing  11  can be superimposed on a wall  1  or integrated in a recess arranged for this purpose in said wall  1 . It can also be formed by the recess itself. This casing can also be supported by an underframe or similar resting on the floor or on any other surface, in a fixed or rolling manner. In the whole text, the expression “casing  11 ” includes all these various possibilities. It includes a cover frame  16  arranged around casing  11  to hide the internal mechanism. This cover frame  16  can be made of a commercially available framing or of a frame designed especially for said device, according to the desired aesthetics. This cover frame  16  can be separate or integrated and belong to a piece of art. 
     The screen device  10  according to the invention includes at least one projection screen  12  and at least one setting  13  superimposed and combined on a same support sheet  14 , in the extension of each other. The support sheet  14  is preferably made of a flexible coated fabric allowing good reflection of a picture projected by a video projector. The projection screen  12  can be made of the raw support sheet  14  itself, of a white or light printing on support sheet  14  or by another fabric added on support sheet  14  by gluing, sewing, etc. It can be delimited or not by a more or less black, more or less wide printed edge, another setting or similar, The setting  13  can be printed on support sheet  14 , directly painted on this sheet to create an original piece of art, or on another fabric added on support sheet  14  by gluing, sewing, etc. It can be a reproduction of a piece of art, an original painting or any other type of setting. 
     Loudspeakers  15  can be integrated in casing  11 , behind support sheet  14 . In this case, support sheet  14  can have micro-perforations in front of said loudspeakers  15 , on the side of projection screen  12 , to let the sound pass. These loudspeakers  15  are preferably flat or extra flat, to require only a reduced space in depth. Of course, device  10  according to the invention can be complemented with other accessories such as a lighting system and further equipment obvious to a person skilled in the art, according to the options offered to the user. 
     The screen device  10  includes displacement means  20  for moving support sheet  14  with respect to casing  11  in order to show to the user either setting  13  (cf.  FIG. 2 ) or projection screen  12  (cf.  FIG. 1 ) according to his choice. These displacement means  20  include at least two parallel winding rollers  21 ,  22 , arranged in two opposite sides of casing  11  and whereon support sheet  14  winds up. In the illustrated example, winding rollers  21 ,  22  are vertical and provided in the right and left sides of casing  11 , support sheet  14  moving horizontally. These rollers can of course be provided horizontally in the upper and lower sides of the casing, the support sheet moves then vertically. At least one of the winding rollers  21  is a driving roller that is motorized, for example with a tubular motor  23  that has the advantage of being mounted inside of the internal diameter of the roller, but any other motor or actuator may be suitable. In the illustrated example, the other winding roller  22  is mounted free in rotation and tensioned by return means  24  that allow stretching support sheet  14  in its horizontal axis of movement, ensuring a fixed center distance E between both rollers  21 ,  22  and therefore compensating the operating play. This return means  24  is represented by a compression coil spring arranged in a housing  25  integral with casing  11  to exert its return force on the axis of said roller  22 , rotatable in said casing  11  in oblong seats that allow a slight play in the horizontal axis. Any other return means can be considered. In a non represented embodiment, this return means  24  can be replaced with another motor driving the second winding roller  22  and an electronic control of the rotary speed of both winding rollers  21  and  22 . 
     Referring to  FIG. 3 , the support sheet  14  forms a closed loop around both winding rollers  21 ,  22  and circulates in the same direction represented by arrow F 1  or in both directions, depending on the motor type chosen. The projection screen  12  and the setting  13  provided on support sheet  14  are superimposed and located in opposition, so that, when setting  13  is located at the front side of casing  11 , projection screen  12  is retracted behind setting  13  inside of casing  11 , and vice-versa. At every pulse sent to motor  23 , the support sheet  14  moves on a distance that allows replacing setting  13  by projection screen  12 , and vice-versa, at the front side of casing  11 . The motor  23  is advantageously controlled remotely by a wireless remote control or any other suitable communication means. 
       FIG. 4  illustrates an embodiment variant of displacement means  30 , including two parallel winding rollers  31 ,  32  provided in the right and left sides of casing  11  (not represented in this figure), two motorized driving rollers  33 ,  34  and two deflection rollers  35 ,  36  provided inside of casing  11 , all these rollers being parallel. At least one of driving rollers  31 ,  32  can be tensioned or not, as in the previous example, by a return element  24 , depending on the type of the motors chosen and the type of control of said motors. In this variant, support sheet  14  does not form a closed loop, but an open loop wherein each of its ends winds on one of driving rollers  33 ,  34  after having moved around a deflection roller  35 ,  36  ensuring its proper positioning whatever the thickness of the sheet wound on driving rollers  33 ,  34 . This deflection roller  35 ,  36  can be optional. Support sheet  14  can therefore have a length that exceeds twice the length of casing  11  in order to offer several projection screens  12  with different sizes and/or different reflective qualities and/or different types of settings  13  placed one after the other, multiplying the possibilities of interchangeable projection screens and/or settings. The motors  37 ,  38 , for example tubular motors, associated with driving rollers  33 ,  34  are synchronized to allow simultaneously unwinding support sheet  14  from one of the rollers  33  and winding it on the other roller  34  and vice-versa, according to the element to be shown on the front side of casing  11 . The motors  37 ,  38  must be able to rotate in both directions of rotation to allow the movement of fabric  14  from left to right and from right to left, as shown by double arrow F 2 . 
       FIG. 5  presents a technical solution slightly different from that of  FIG. 4 , wherein the displacement means  40  include one single motor  47 . It also includes the two parallel winding rollers  41 ,  42  provided in the right and left sides of casing  11  (not represented in this figure), two driving rollers  43 ,  44  and two deflection rollers  45 ,  46  provided inside of casing  11 . Only one of the driving rollers  43  is motorized and drives the other driving roller  44  by means of a transmission  48  using a timing belt, a chain, gears or similar, ensuring a synchronization between rollers  43 ,  44 . 
     The screen device  10  according to the invention furthermore comprises stiffening means  50  associated with the two free edges  14   a  of support sheet  14  to stiffen them in the winding direction of said sheet and confer to the support sheet  14  a perfect flatness at least on the whole of its surface exposed on the font side of casing  11 . Referring more specifically to  FIGS. 6 to 8 , these stiffening means  50  comprise a preferably metallic strap  51  out of spring steel, slightly curved or flat, fixed on the free edges  14   a  of support sheet  14 . Strap  51  can be made out of any other material offering equivalent mechanical properties such as aluminum, aluminum alloy, stainless steel or any other steel or alloy, or also any suitable synthetic or composite material. This strap  51 , which can be compared with a metallic measuring tape, has the advantage of being rigid in its length along its longitudinal axis X and in its width along its transversal axis Y, and flexible in its thickness so as to be able to flatten when it is curved, and to wind on itself in a small space, so that it winds up easily with carrier frame  14  on the winding rollers  21 ,  22  of  FIG. 3 , but also around the other rollers described referring to  FIGS. 4 and 5 , without generating an excess thickness that might lead to irreversible folds on support sheet  14 . This strap  51  has a narrow width and a thickness that is negligible with respect to its length. Its length must be identical to that of support sheet  14 . It is fixed on the free edges  14   a  of support sheet  14  in particular by gluing, using a cold glue, for example a flexible glue of the Patex® type, or by any other equivalent definitive fixing means compatible with the material of support sheet  14  and of strap  51 . Strap  51  is partly fixed on support sheet  14 , that is to say on a section only of its width, to let free its both longitudinal edges, which define a free inside edge  51   a  and a free outside edge  51   b  located on either side of the free edge  14   a  of support sheet  14 . Of course, the free edge  14   a  of the sheet can coincide with the free outside edge  51   b  of strap  51 . This strap  51  has the advantage of being neither extensible nor deformable in its length or in its width, ensuring a perfect mechanical resistance of free edges  14   a  of support sheet  14  and an induced tension of support sheet  14 , therefore avoiding any crease, wave and other deformation of support sheet  14  that would be detrimental to the quality of support sheet  14  itself and to the projection quality it ensures, even on great lengths according to center distance E of rollers  21 ,  22 . Moreover, this strap  51  can be wound on itself without fatigue or wear, offering a reliable and durable solution. Along center distance E, the straps  51  provided on both free edges  14   a  of support sheet  14  are sufficient to stretch support sheet  14  uniformly and permanently. 
     The screen device  10  according to the invention moreover comprises guide means  60  for the free edges  14   a  of support sheet  14  using the stiffening means  50  in order to prevent any transversal shift of support sheet  14  with respect to the winding rollers. An example is illustrated in reference to  FIG. 8  and comprises longitudinal grooves  61  arranged to receive by sliding the inside edges  51   a  of straps  51 . These longitudinal grooves  61  are carried by a supporting profile  62  mounted in casing  11  by any known means, such as fastening screws (not represented). In this example, supporting profile  62  is a hollow rectangular profile and grooves  61  are arranged in C-shaped guides  63  mounted on both sides of profile  62  to guide support sheet  14  as well on the front side of casing  11  as inside of casing  11 . The upper loop of guide  63  is configured to hold upper side  51   b  of strap  51 . The sliding of strap  51  is thus perfectly guided during the displacement of support sheet  14 , ensuring a linear displacement and proper positioning of fabric  14 . The guides  63  can preferably be made out of or coated with a material with a low coefficient of friction such as Teflon®. These guides  63  extend longitudinally between the two winding rollers  21 ,  22  to guide the lower and upper free edges  14   a  of support sheet  14 . They can be continuous or discontinuous. 
       FIGS. 6 and 7  illustrate an embodiment variant of guide means  70  that allows, in addition to guiding the free edges  14   a  of support sheet  14 , self-centering of this support sheet  14  in order to prevent any deviation during its displacements. They include longitudinal grooves  71  arranged to receive by sliding the inside edges  51   a  of straps  51 . These longitudinal grooves  71  are carried by a supporting profile  72  mounted in casing  11  by any known means, such as fastening screws  73  holding brackets  73   a . In this example, supporting profile  72  is a cylindrical hollow profile that delimits external locations  74  arranged to receive C-shaped elastictapes  75  carrying at their ends guides  76  with the grooves  71 . These guides  76  are arranged on either side of profile  72  to guide support sheet  14  as well on the front side of casing  11  as inside of casing  11 . The fact that the front and rear guides  76  are connected together two by two by an elastic tape  75  allows balancing the tension between the section of support sheet  14  located at the front side of casing  11  and the section of support sheet  14  located inside casing  11 , therefore allowing the auto-centering of support sheet  14 . The guide means  70  are complemented with a semi-cylindrical external guide  77  located in casing  11  to hold the external edges  51   b  of straps  51 . As previously, guides  76  and  77  can be made out of or coated with a material with a low coefficient of friction such as Teflon®. They extend longitudinally between the two winding rollers  21 ,  22  to guide the lower and upper free edges  14   a  of support sheet  14 . They can be continuous or discontinuous. 
     The guide means  60  and  70  can be combined, for example mounting guide means  60  along one of the free edges  14   a  of support sheet  14  and the other guide means  70  along the other free edge. Likewise, other guide means  80  as the ones described in reference to  FIG. 12  can integrate permanent tensioning means of support sheet  14 . Of course, any other guide means can be suitable, such as castors, rollers or similar allowing guiding without friction the free edges  14   a  of support sheet  14 . 
       FIGS. 9 to 12  illustrate another variant of the retractable screen device  100  according to the invention, wherein casing  111  is no more fixed and solid as in the previous example, but telescopic. This embodiment variant allows adapting the opening of casing  111  according to the use of screen device  100 . In  FIG. 9A , casing  111  is in closed position and shows to the user a setting  13  that can be a piece of art. In  FIG. 9B , this casing  111  is in a first open position that can for example correspond to a 16:9 size screen and, in  FIG. 9C , this casing  111  is in a second open position that for example correspond to a 2.25:1 size screen. 
     In this case, casing  111  is specific and is an integral part of screen device  100 . To that purpose, casing  111  includes, in reference to  FIGS. 10A and 10B , two end panels  112 ,  113  that carry the winding rollers  31 ,  32  of the driving means  30  of  FIG. 4  for example, a bottom panel  114  and two intermediate stages formed by two sets of intermediate panels  115 ,  116 . The end panels  112 ,  113  and the intermediate panels  115 ,  116  are mounted on telescopic rails or slides  118 , preferably on balls or needles (represented in  FIG. 11B ), so as to be moved with respect to each other like a drawer. The intermediate panels  115 ,  116  can be replaced with slides  118 . The two end panels  112 ,  113  are tensioned towards their open position by return means  117 ,  120  that tend to move them away from each other and they are held in closed position by motors  37 ,  38  coupled to said driving rollers  33 ,  34 . In the example illustrated in  FIGS. 10A and 10B , the return means  117  are represented by compression springs. In the example illustrated in  FIGS. 11A and 11B , the return means  120  are represented by lozenge-articulated arms  121  that are tensioned in opening direction by return means  122  represented by dot-and-dash lines, such as for example compression springs, forming a type of pantograph. These return means  120  allow achieving a stable position also in closed position. Of course, any equivalent means may be suitable, such as spring jacks, gas springs or similar. 
       FIG. 10A  shows screen device  100  in retracted position showing to the user for example a setting  13  on its support sheet  14 . The intermediate panels  115 ,  116  are superimposed on end panels  112 ,  113  and on bottom panel  114 , defining a first center distance E 1  between the two parallel rollers  31 ,  32 . As soon as the user commands the start of one of the motors  37  to replace his setting  13  with a projection screen  12 , support sheet  14  unwinds from the corresponding driving roller  33 , releases return means  117  and generates the opening of casing  111  in a way centered on its bottom panel  114 . When the user sees projection screen  12  arrive, he commands the start of motor  38  to wind up setting  13  while going on unwinding projection screen  12  with motor  37 . As soon as setting  13  has disappeared from the front side of casing  111 , the user stops the corresponding motor  38  and continues opening projection screen  12  using motor  37  until it appears totally, and he then stops the corresponding motor  37 . Casing  111  is in open or deployed position represented in  FIG. 1  OB wherein the parallel rollers  31 ,  32  define a second center distance E 2  that can be equal at least to 1.5 times the first center distance E 1 . This telescopic casing  111  allows deploying projection screens  12  with a size much larger than setting  13  and therefore reducing the space required on the wall or on the floor by screen device  100 . This embodiment variant also allows displaying different sizes and/or different reflective qualities for projection screen  12 , depending on whether support sheet  14  is unwound on a more or less important length between minimum center distance E 1  and maximum center distance E 2 . Of course, this embodiment variant also includes stiffening means  50  associated to support sheet  14 , as well as its guide means  60 ,  70  provided in particular in the end panels of casing Ill and on the front side of casing  111  by an unwinding guide system or similar. It goes without saying that the control of motors  37 ,  38  can be entirely automated with an electronic control unit and determined according to the screen type, which the operator can select with a remote control. Likewise, depending on the return means  117 ,  120  used, the opening of casing  111  can be achieved simply by releasing progressively the motor brake of motors  37 ,  38 . 
     Other guide means  80  can be provided, such as those illustrated in  FIGS. 11 and 12  and mounted on the rails or slides  118  in the upper and in the lower section of said screen device  100  so as to move simultaneously with the displacement of support sheet  14  when opening or closing said casing  111 , in order to ensure a uniformly distributed guidance of free edges  14   a  of support sheet  14 . Each of them includes a supporting plate  81  that is either mounted stationary on the end panels  112 ,  113 , or sliding on slides  118 , or stationary on additional slides  119 . The mobile supporting plates  81  are connected together by small chains  82 , twines or similar so as to move with a controlled center distance. The guide means  80  moreover include a C-shaped guide  83  that delimits a groove  84  to guide support sheet  14 . The upper loop  85  of guide  83  is configured to hold upper side  51   b  of strap  51 . This guide  83  is tensioned by return means  86  towards the outside of casing  111  in order to exert permanently a tension on support sheet  14  from the inside towards the outside of the sheet. To this purpose, this guide  83  is mounted between two profiles  87  fastened onto supporting plates  81  by screwing or similar and slidably guided on rods  88 . In the example represented, the return means  86  are made of compression springs guided on rods  88 . This way, strap  51  is perfectly guided while sliding during the displacement of support sheet  14 , which is constantly tensioned. As in the previous examples, the guides  83  can be made out of or coated with a material with a low coefficient of friction such as Teflon®. 
     The embodiment variant according to  FIGS. 9 to 12  allows integrating easily one or several projection screens  12  in a three-dimensional piece of art such as for example a sculpture forming a setting  13 . In this case, if screen device  100  stands on the floor, casing  111  in its closed position, associated or not with a cover frame  16 , as well as the underframe (not represented), can form said piece of art. Casing  111  can therefore have a three-dimensional shape that is not necessarily a parallelepiped. The opening of casing  111  generates the opening of the piece of art that shows support sheet  14  which, in this case, only comprises one or several projection screens  12 , as the setting  13  is formed by the outside of said screen device  100 . 
     Possibilities for Industrial Application: 
     This description shows clearly that the invention allows reaching the goals defined, that is to say a retractable projection screen device that is multifunctional, modulable and that can evolve by changing support sheet  14 , with a simple and reliable design, easy to use, aesthetic and ergonomic, therefore allowing increasing the number of potential users of this home cinema technology, being specified that this device can have both domestic and professional applications. In particular for . professional purposes, the content of support sheet  14  can of course be modified according to the specification sheet and to the targeted customers, This content can for example include advertising, promotional, technical, commercial, etc. information. 
     The present invention is not restricted to the examples of embodiment described, but extends to any modification and variant which is obvious to a person skilled in the art while remaining within the scope of the protection defined in the attached claims.