You are an expert at summarizing long articles. Proceed to summarize the following text:

You are an expert at summarizing long articles. Proceed to summarize the following text: 
TECHNICAL FIELD 
     The present invention relates to an automatic door with flexible curtain. 
     BACKGROUND 
     Automatic doors with flexible curtain typically comprise two lateral uprights, a transverse case connecting the upper ends of the lateral uprights, and a curtain movable between a closing position in which it obstructs the opening formed by the transverse uprights and the case and an opening position in which the curtain is folded or rolled into the case. Driving means, conventionally arranged in or on one of the sides of the case, allow displacement of the curtain from the closing position to the opening position and vice versa. 
     An important issue in the field of the automatic doors with flexible curtain concerns securing the operation of these doors in order to avoid, during displacement of the curtain from the opening position to the closing position, a collision between the curtain on the one hand and a person or a vehicle on the other hand, which may cause injury to the person or deterioration of the vehicle and/or deterioration of the curtain. 
     A solution known from patent FR2877684 consists of integrating into the curtain means for detecting an encounter with an obstacle in order to secure the operation of the door. The means for detecting an encounter with an obstacle are connected by a wired connection to the electronics or electromechanics for controlling the driving means of the curtain. Therefore, the triggering of the means for detecting an encounter with an obstacle allows for example, via the control electronics or electromechanics, ordering the driving means to stop the closing of the curtain and to move it in the opposite direction in order to open it. 
     This solution offers high reliability of detection of an obstacle and allows quite satisfactorily to preserve the physical integrity of the vehicle or of the person accidentally hit by the curtain, and the physical integrity of the curtain itself. 
     However, the wired connection connecting the detection means to the control electronics or electromechanics is at least partially exposed to attack from the outside environment. 
     This may be problematic when the door is for example exposed to bad weather and hydrometric variations, due to the increased risk of deterioration of the quality of the electrical connection. In addition, the wired connection is easily accessible; thus it risks to be sectioned, accidentally when a vehicle passes nearby or with malicious intent. 
     Moreover, given the speed of displacement of the curtain and the frequency of its displacements, the wired connection between the means for detecting an encounter with an obstacle and the control electronics or electromechanics is subject to a risk of premature wear, or even breakage upon a displacement of the curtain. This results in reliability problems that can be limited only by means of regular maintenance. 
     Then, the wired connection is limitative in terms of dimensioning of the door that it equips; it is difficult to implement as a solution to detect obstacles similar to that described in the patent FR2877684 for a door of significant dimensions, for example intended for the passage of an aircraft into or out of a hangar. 
     Finally, and most importantly, within the framework of applications in the fields of pharmaceuticals or food processing, the door can mark the entry or exit point of a clean room and must thus be cleaned regularly. However, cleaning the wired connection, typically a spiral wire that extends or retracts as to whether the door closes or opens, may be tedious when done by hand, or can cause premature wear of this wired connection when it is carried out by means of cleaning products which can be corrosive (after a number of cleaning operations, the spiral wire gradually loses its flexibility and could end up breaking). 
     BRIEF SUMMARY 
     The present invention aims to overcome all or part of these drawbacks by proposing a door with flexible curtain offering high efficiency of detection of obstacles and great ease of cleaning, while being less sensitive to attack from the outside environment and the main causes of premature wear. 
     To this end, the present invention provides a door with flexible curtain comprising a structure including uprights and a transverse element allowing to guide a flexible curtain provided with a ballasting and sealing element at its free end and at least one reinforcing element parallel to the ballasting and sealing element, the door also comprising driving means supported by the structure allowing to maneuver the curtain between an opening position and a closing position, and means for detecting encounter with an obstacle likely to cause, when activated, the stopping and/or reverse displacement of the curtain, carried at least partly by a supporting element and integrated within the lower part of the curtain, the means for detecting encounter with an obstacle being situated upstream of the ballasting and sealing element, on the closing trajectory of the curtain, between the reinforcing element and the ballasting and sealing element, characterized in that the door comprises at least one emitter, each emitter cooperating with the means for detecting encounter with an obstacle in order to emit a radio signal following the triggering of the means for detecting encounter with an obstacle, the radio signals emitted by each emitter can be received by at least one receiver cooperating with the means for driving the curtain consecutively to the triggering of the means for detecting encounter with an obstacle, and in that the curtain comprises at least one support means arranged in proximity to one of the uprights in order to support each emitter in a lateral area of the curtain. 
     Therefore, the door according to the invention equipped with a wireless connection is freed from the traditional constraints connected to wired connections, particularly in terms of the time spent to the cleaning of this wired connection, in terms of attack from the outside environment and in terms of wear of this wired connection. The door according to the invention allows thus transmitting with great reliability a signal following the triggering of the detection means. 
     Moreover, it is noted that the arrangement of the emitter in a lateral area of the curtain, that is to say in an area of little exposure to collision risks, substantially limits the risk of deterioration of the emitter which may result from the accidental collision of a vehicle or a person with the curtain. 
     It is noted that, the means for detecting encounter with an obstacle may correspond to means for detecting encounter with an obstacle by contact, that is to say, they may correspond to means for detecting a contact between the curtain and an obstacle. 
     According to a characteristic of the door according to the invention, the communication between each receiver and each emitter is bidirectional in order to control a state of correct operation of each emitter. 
     According to a form of execution, each emitter comprises a secondary receiver, each receiver integrating at least one secondary emitter capable of emitting a radio signal towards the secondary receiver of each emitter in order to control the state of correct operation of each emitter. 
     Advantageously, the state of correct operation corresponds to a charge level of at least one built-in battery or battery cell integrated into each emitter greater than a predetermined charge level threshold. 
     According to one possibility, the receiver is configured to control a state of correct operation of each emitter only during the displacement of the curtain towards the closing position. 
     This has the advantage of limiting the energy consumption of each emitter, thus increasing their battery life. 
     Advantageously, the door comprises alerting means intended to inform a user of the absence of the state of correct operation of the emitter or at least one of the emitters. 
     According to an embodiment, the emitter or the at least one of the emitters onboard at least one amplifier of an infrared signal transmitted between an emitting cell and a receiving cell of the means for detecting encounter with an obstacle. 
     Therefore, the amplifier of the infrared signal is less exposed to the risk of breakage following a contact between the curtain and an obstacle, this contact leading to the cutoff of the infrared signal by deformation of the ballasting and sealing element. 
     According to one embodiment, each support means corresponds to at least one pocket adapted to contain the emitter or the at least one of the emitters. 
     According to an embodiment, the pocket is arranged inside the curtain. 
     According to one possibility, the pocket is suspended from a sleeve containing the supporting element, and is attached to the sleeve by welding. 
     The pocket can be suspended from the sleeve containing the supporting element of the cells, when the means for detecting encounter with an obstacle comprise emitting/receiving cells. 
     According to a form of execution, the curtain comprises an inspection shutter arranged to permit access to the emitter or at least one of the emitters. 
     The inspection shutter may advantageously offer direct access to the emitter or the at least one of the emitters, or give access to the pocket if this emitter is placed in the pocket. 
     According to one possibility, each emitter is spaced apart from one of the uprights by a distance comprised between 5 cm and 40 cm, preferably between 10 cm and 15 cm. 
     Advantageously, the emitter or the at least one of the emitters is arranged inside the curtain, preferably in the lower part of the curtain between the reinforcing element and the ballasting and sealing element. 
     An emitter placed outside risks indeed de be clung and deteriorated in the case of a light touch of the curtain by a person or a vehicle. 
     In addition, the emitter placed in the lower part of the curtain is in proximity to the means for detecting encounter with an obstacle. The required connection between the emitter and the means for detecting encounter with an obstacle is thus easier to implement. 
     Advantageously, the alerting means may comprise at least one indicator lamp. This indicator lamp is placed to be easily visible to a user. 
     According to one possibility, the supporting element coincides with the reinforcing element. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Other characteristics and advantages of the present invention will become apparent from the below description of an embodiment of the invention, given by way of non-limiting example, with reference to the accompanying drawings in which: 
         FIGS. 1 and 3  are partial cross-sectional side views of the lower part of a vertical rolling door curtain according to an embodiment of the invention (emitter not visible), 
         FIGS. 2 and 4  are sectional views, respectively along line II-II of  FIG. 1  and line IV-IV of  FIG. 3 , 
         FIG. 5  is a schematic front view of the vertical rolling door curtain, 
         FIG. 6  is a front view of the inside of the lower part of a vertical rolling door curtain, 
         FIG. 7  is a schematic perspective and partial sectional view of the lower part of a vertical rolling door curtain, 
         FIG. 8  is a schematic sectional and profile view of the lower part of a vertical rolling door curtain, 
         FIGS. 9 and 10  are respectively front and profile views of a pocket for supporting an emitter of a door according to an embodiment of the invention, 
         FIG. 11  is a perspective view showing an inspection shutter of the door curtain according to an embodiment of the invention. 
     
    
    
     DETAILED DESCRIPTION 
       FIGS. 1 and 3  show the lower part of a door  1  with vertical rolling flexible curtain  2 . 
     Generally, it is about doors having a structure comprising uprights  4  and a transverse element  5  allowing to guide the curtain  2 , and driving means  3  (electric motor, reducer, control electronics or electromechanics) supported by the structure allowing to maneuver the curtain  2  between an opening position and a closing position. 
     As is also visible in  FIGS. 2 and 4 , the curtain  2  comprises at its free end a ballasting and sealing element  6  and means for detecting encounter with an obstacle, such as those described in the patent document FR2877684. 
     According to the embodiment illustrated in  FIGS. 1 to 11  and given by way of example, the means for detecting encounter with an obstacle comprise an emitting cell  8 , that emits an optical (infrared) beam  10  parallel to and upstream of the ballasting and sealing element  6 , and a receiving cell  12  arranged facing the emitting cell  8 . An emitting/receiving cell cooperating with a passive beam-return cell can also be considered. Several emitting cell  8 /receiving cell  12  couples can also be considered in order to increase the width of the door  1 . The detecting means also comprise at least one detecting flag  14  for each emitting cell  8 /receiving cell  12  couple. The detecting flag  14  can be constituted by an L-profile. It is supported here by the ballasting and sealing element  6 . 
     The operation of the detecting device is as follows. When the ballasting and sealing element  6  encounters an obstacle during its descent, it deforms as it is constituted for its essential part by a spring  16  and a foam sheath  18 . The deformation of the ballasting and sealing element  6  modifies the base of the detecting flag  14  which cuts off the beam  10  which is normally parallel to the ballasting and sealing element  6 . The beam  10  being cutoff, a signal is sent to the control electronics or electromechanics of the door  1  which then gives the order, on the one hand, to stop the closing of the curtain  2 , and on the other hand, to re-open it. 
     As is visible in  FIGS. 1 to 4 , the emitting cell  8  and the receiving cell  12  are each supported by a prop  20 . Each prop  20  is here fastened to a supporting element  22 . The supporting element  22  is substantially parallel to the ballasting and sealing element  6  and allows supporting the means for detecting encounter with an obstacle. The supporting element  22  may correspond to a reinforcing element  24  or a transverse stiffening bar integrated into the curtain  2 , as is the case in  FIGS. 1 to 5 , or be dissociated therefrom, as is the case in  FIGS. 6 to 8 . 
     According to one possibility, each reinforcing element  24  is guided but not retained, and is adapted to withstand multidirectional shocks. 
     It is noted that each prop  20  may present a plurality of areas  26  for hosting the emitting cell  8  or the receiving cell  12 , such that the center distance existing between the ballasting and sealing element  6  and the axis of the beam  10  can be varied. 
     According to the embodiment illustrated in  FIGS. 1 and 2 , it is noted that the curtain  2  presents, not only a single apron, but two aprons  34 ,  36 . At the end of the curtain  2 , a U-shaped tarpaulin  30  fixed to each one of the aprons  34 ,  36  is provided, in which a sleeve  32  receiving the ballasting and sealing element  6  is formed. In addition, the curtain  2  can comprise two adjacent reinforcing elements  24  connected by a spacer  25 . 
     In the embodiment of  FIGS. 3 and 4 , it is noted that the curtain  2  presents a single apron  28  which, at its lower end, presents a U-shaped tarpaulin  30  which is fixed on each one of the faces of the apron. A sleeve  32  is formed in the U-shaped tarpaulin in order to receive the ballasting and sealing element  6 . 
     As is visible in  FIG. 5 , the door  1  comprises quite remarkably at least one emitter  38  intended to cooperate with the means for detecting encounter with an obstacle in order to emit a radio signal following the triggering of the means for detecting encounter with an obstacle. Therefore, each receiving cell  12  can be connected to an emitter  38 , for example by a wired connection  40 . 
     When the door  1  comprises several emitters  38 , the emitters  38  operate independently of one another. 
     According one a possibility, the door  1  comprises at least two detecting assemblies, for example at least two emitting cell  8 /receiving cell  12  couples, and two emitters  38 , each emitter  38  being associated with one of the detecting assemblies. 
     Therefore, quite advantageously, the alignment of several detecting assemblies aligned parallel to the ballasting and sealing element  6  and associated each with an emitter  38  allows the production of doors  1  of large width. For example, the door  1  may comprise two beams  10  of 5 m, each one associated with an emitter  38  independent of one another, in order to produce a door  1  with a width of approximately 10 m. 
     In the example of  FIG. 5 , two emitters  38  have been represented. 
     As can be seen in  FIG. 5 , the emitters  38  are remarkably arranged in proximity to one of the uprights  4 , in other words in proximity to one of the lateral edges  42  of the curtain  2 . Quite advantageously, the emitters  38  are therefore situated in an area less exposed to the risks of collision with a person or a vehicle. 
     Each emitter  38  is distant from one of the uprights  4  by a predetermined distance d which may be comprised between 5 cm and 40 cm, and preferably between 10 cm and 15 cm. 
     Each emitter  38  can cooperate with a receiver  44  located in the vicinity of the door  1 , that is to say by a distance which enables the establishment of a radio connection between each emitter  38  and the receiver  44 . 
     The receiver  44  can be single. 
     The receiver  44  is adapted to receive the radio signals emitted by each emitter  38 . The receiver  44  is intended to cooperate with control electronics or electromechanics in order to control the means for driving the curtain  2  so as to stop and/or move the curtain  2  consecutively to the triggering of the means for detecting encounter with an obstacle. 
     It is noted that, advantageously, when the door  1  comprises a detecting assembly with infrared beam  10 , the emitter  38  associated with this detecting assembly can onboard at least one amplifier  60  of an infrared signal transmitted between the emitting cell  8  and the receiving cell  12  of this detecting assembly. 
     Quite remarkably, the communication between each emitter  38  and the receiver  44  is bidirectional. 
     In other words, the radio signals can be emitted from each emitter  38  to the receiver  44 , and from the receiver  44  to each emitter  38 . The frequency can be for example in the order of 2.4 GHz. 
     The communication can be simultaneous for a better response time (the emitter  38  and the receiver  44  can emit and receive signals simultaneously). 
     Thus, the receiver  44  is capable of monitoring a state of correct operation of each emitter  38 , at least during the displacement of the curtain  2  up to the closing position and, where appropriate, only in this case in order to increase the battery life of the emitters  38 . 
     The receiver  44  may for example examines each emitter  38  about the charge level of the battery cell(s) or battery(ies) it integrates in order to supply. 
     According to one possibility, the receiver  44  can therefore integrate at least one secondary emitter (not represented) capable of emitting a radio signal, and each emitter  38  can integrate a secondary receiver (not represented) capable of receiving one of the radio signals emitted by the secondary emitter or one of the secondary emitters integrated into the receiver  44 . 
     The door  1  can comprise alerting means, for example an indicator lamp (not represented), intended to alert a user when the receiver  44  has detected a low level of battery charge for the emitter or one of the emitters  38 . 
     In this case, the indicator lamp illuminates in order to indicate this low battery state to a user, and it can be considered to move the curtain  2  to the opening position while awaiting the intervention of an operator. 
     The operator may proceed to the replacement of the used battery cell or battery by moving the curtain  2  in maintenance mode and accessing, where appropriate, the concerned emitter  38  via an inspection shutter  45 , visible in  FIG. 11 . 
     Each inspection shutter  45  is arranged to permit access to an emitter  38 . The inspection shutter  45  may correspond to a cutout arranged in the curtain  2  in order to delimit an opening  47  permitting access to the emitter  38 . It may comprise closing means, for example of the hook and loop types, intended to maintain the cutout folded over the opening  47  in order to obstruct it. 
     The inspection shutter  45  is arranged in proximity to the emitter  38 . It is dimensioned in order to allow passage of the emitter  38  through the opening  47  it delimits. Ideally, the inspection shutter  45  is also shaped in order to permit access to means for detecting encounter with an obstacle. It may thus allow the replacement of an emitting cell  8  or a receiving cell  12 . 
     At least one support means, such as a pocket  46  represented in  FIGS. 6 to 10 , allows supporting each emitter  38 . 
     The pocket  46  may correspond to a PVC canvas; its dimensions (for example length L in the order of 300 mm and height h in the order of 120 mm) are adapted to contain the emitter  38  (the dimensions of which can be in the order of 15 cm in length, 3 cm in height and 2 cm in width). 
     The pocket  46  is arranged in proximity to one of the uprights  4  in order to support each emitter  38  in a lateral area of the curtain  2 . 
     According to the embodiment illustrated in  FIGS. 6 to 8 , the pocket  46  is situated in the curtain  2 , such that the emitter  38  it contains is situated in the curtain  2 . More precisely, the pocket  46  may be arranged in the lower part of the curtain  2 , in particular in the U-shaped tarpaulin  30 , between the reinforcing element  24  or the supporting element  22  and the ballasting and sealing element  6 . The emitter  38  it contains is therefore in immediate proximity to the means for detecting encounter with an obstacle. 
     As is visible in  FIGS. 6 to 8 , the pocket  46  may be suspended from a sleeve  48  containing the supporting element  22 . An upper portion  50  of the pocket  46  is for example welded to the sleeve  48 . 
     As is visible in  FIGS. 9 and 10 , the pocket  46  may correspond to a cutout, two opposite edges of which are folded one against the other and welded to one another in order to delimit an internal volume intended to receive the emitter  38 . The pocket  46  comprises two ends, one of which ( FIG. 10 ) is locked (welded edges) and the other of which (to the right of  FIG. 9 ) is intended to allow the insertion or removal of the emitter  38  in or out of the pocket  46 . 
     Closing means, for example of the snap button, hook and loop, slide fastener, or self-locking collar types  52  (inserted in holes  54  arranged on the pocket  46 ), allow closing the end intended to the insertion or removal of the emitter  38 . 
     Of course, the invention is in no way limited to the embodiment described above, this embodiment having been given only by way of example. Modifications remain possible, especially from the point of view of the constitution of the various elements or by the substitution of technical equivalents, without for all that departing from the field of protection of the invention. 
     Therefore, the invention can also be applied to doors with horizontal or vertical folding or rolling flexible curtain. 
     It is noted that the means for detecting encounter with an obstacle is not limited to an infrared beam transmitted between an emitting cell and a receiving cell. They may also comprise a mechanical system with a cable which, at one of its ends, is retained by a spring at a prop  20  and, at its other end, is retained through a pull-type contact. It is also conceivable to use an air flange associated with a pressure switch. 
     When the door  1  comprises several aligned detecting assemblies, these may be of different types (for example infrared system and mechanical system). Where appropriate, the emitters  38  are configured to receive the signals outputted by the detecting assembly to which they are associated. 
     The invention also allows the production of assemblies comprising several doors  1  and a single receiver  44  placed in the vicinity of each one of these doors  1  in order to cooperate with the emitter  38  or the emitters  38  of each one of the doors  1 .

Summary:
A flexible curtain has a ballasting and sealing element and a reinforcing element, and is able to move between an open position and a closed position. The door comprises a detection unit configured to detect an encounter of the ballasting and sealing element with an obstacle. The door also comprises a wireless emitter arranged inside the curtain, close to an upright, in a lateral region of the curtain. The emitter cooperates with the detection unit and emits a radio signal when the obstacle is detected by the detection unit. The radio signal is received by a receiver which cooperates with a driving unit so as to stop or reversely move the curtain.