FR2770174A1 - Machine for double-sided scanning or printing of sheets - Google Patents

Abstract

The mechanism has a paper handling feed drum (13) that rotates on a support to position the paper in front of an optical scanner or a printer (14). A paper sensor (40) activates an actuator (43) on the drum which cooperates (45) with a detector (36) on the drum so that only when the handling drum is in the correct position can paper be delivered for processing.

Description

 The invention relates to a device for processing sheets, more particularly a device capable of performing two-sided processing of such a sheet; it relates more particularly to an improved mechanism making it possible both to efficiently manage the rotation of a movable assembly between a front processing position and a back processing position and to detect certain operating anomalies.

The invention is remarkable in that this mechanism is capable of performing all these functions by using only one sensor, for example of the electro-optical type. In the case of the processing of sheets of paper for office automation applications, the aforementioned processing can consist, for example, of reading graphical information located on a sheet moved inside the device or on the contrary of printing information on a such sheet.

 Several devices of the type indicated above are known, adapted to operate a double-sided treatment of a sheet, that is to say a treatment on each of the faces of the sheet. For example, document JP 63136762 describes such a processing device comprising several sheet access arrangements arranged on either side of a processing space comprising, combined in a rotating movable assembly, a guide arrangement defining a path for the passage of a sheet and a processing unit installed on the side of this guide. After a treatment in recto mode, a rotation of 1800 of this mobile assembly allows the treatment unit to be turned over with respect to the path and consequently, treatment in verso mode by reversing the direction of movement of the sheet after rotation of the mobile equipment.

 By sheet access arrangement means any equipment constituting a means of entry of the sheet making it possible to introduce it into the movable assembly, or an outlet means making it possible to extract it or else a means of input-output allowing in particular, according to the selected operating mode, to extract a sheet from the processing space and then to reinsert it. Such an input-output means can for example be used to temporarily store a sheet (after a treatment in recto mode) outside of the treatment space while the moving element moves to the treatment position on the back and to reintroduce the same sheet in the processing space to allow its processing in reverse mode.

 In any event, such a sheet processing device is at least equipped with two input-output means generally located on either side of the rotating moving element. It can also include an input means, optionally equipped with an automatic sheet feeding device, an input-output means located opposite this input means for temporarily retrieving and storing the sheet. after its treatment in recto mode and an exit means for evacuating the sheet reintroduced into the moving element by the entry-exit means, after its treatment in verso mode.

The invention defined below applies to a device comprising any combination of access arrangements defined above.

 In such a device, it is very important that the moving element is well positioned relative to the access points, during the front or back processing of a sheet; improper positioning may result in an operating anomaly commonly called "paper jam", which can damage the sheet.

 The invention aims in particular to better control an operating position of the moving assembly, concomitantly with the passage of a sheet.

To this end, the invention essentially relates to a sheet processing device comprising:
a movable assembly rotatably mounted on a support and housing a processing unit and a sheet guiding arrangement defining for the latter a processing path passing opposite said processing unit, said movable assembly being able to take two predetermined processing positions ,
- at least two sheet access arrangements arranged at predetermined locations on the periphery of said movable assembly and integral with said support,
- a first sheet presence detection probe carried by said mobile assembly,
- a sensor mounted on said support and capable of assuming two predetermined states,
characterized in that said first probe is linked to a first actuating element of said sensor, mounted movably on said movable assembly and in that said first actuating element comprises a first part in position to cooperate with said sensor only when the mobile equipment is in a first treatment position, said first part being able to change the state of said sensor when said probe is actuated by a sheet.

 Advantageously, the first actuating element comprises a second part in a position to cooperate with the sensor only when the moving element is in a second treatment position. This second part is able to change the state of the sensor when the probe is actuated by a sheet. Typically, the first actuating element is arranged to pass the sensor from a first state to a second state when the moving element is in said first treatment position and the probe is actuated by the sheet and to pass the sensor of said second state to said first state when the moving element is in the second treatment position and the first probe is actuated.

 It is important to note that for such a treatment position, the corresponding part of said first actuating element forming a shutter is at least in the vicinity of said space (that is to say just outside or inside ) when the moving element is in one or other of these treatment positions so as to be able to change the state of the sensor when said first probe is actuated by a sheet.

 The sensor can simply consist of a transmitter and a receiver; a sensor sensitivity space (or sensitivity zone) is thus defined in the vicinity of the sensor, capable of being crossed by a beam delivered by the transmitter. The transmitter and the receiver can for example be arranged opposite one another and separated by this space.

 For example, the emitter can be a light source and the receiver a photosensitive cell, separated by said space. In this case, said first actuating element can be a pivoting shutter capable of interrupting a beam (here a light beam) passing through said space between the transmitter and the receiver. This flap has two aforementioned parts which are located respectively in the vicinity of the sensor when the moving element is in one or the other of its treatment positions. The sensor changes state (the signal available at the output of the photosensitive cell suddenly passes from one level to another), in particular when said first probe is actuated by a sheet passing through the moving element during a recto treatment or back, respectively. This first sheet presence detection probe is integral with the movable assembly and placed in the vicinity of an entrance to the guide arrangement thereof.

 According to another advantageous characteristic of the invention, the same sensor is used to detect certain operating anomalies.

 Thus, a second sensor actuating element, pivotally mounted on the movable assembly is resiliently urged to project outwardly from said movable assembly so as to be able to change said state sensor. When the moving element is in the first treatment position, the second actuating element is in a retracted position in the vicinity and outside of a sensitivity zone of the sensor. To do this, this second actuating element can cooperate with a fixed stop (in said first treatment position of the moving element) which keeps it in the retracted position. Consequently, as soon as the moving element leaves said first treatment position (that is to say the front operating position) the second actuating element pivots and a flap thereof is placed in a position such that 'it can interrupt the beam crossing the aforementioned space of said detector.

 Consequently, from the start of the rotation of the mobile assembly from its front processing position towards its back processing position, the pivoting of the second actuating element causes a momentary change of state of the sensor which constitutes confirmation of the setting in motion of the moving equipment.

 On the other hand, the second actuating element is linked to a second sensor for detecting the presence of a sheet carried by the moving element and placed in the vicinity of an outlet from the guide arrangement. Consequently, the assembly is such that said second actuating element remains in the retracted position as long as a sheet is in contact with said second probe. If the second actuating element thus remains retracted due to the presence of a sheet when the moving assembly has already started to rotate, this means that there is an operating anomaly, namely that a sheet remained blocked between the moving element and the exit means.

 Under these conditions, the confirmation pulse is not produced by the sensor receiver and an error message is produced, accompanied by an order to stop the drive engine of the moving equipment. This occurs from the start of the rotation of the moving element so that the sheet is generally not damaged.

 Finally, the moving element can carry other actuating elements of the sensor distributed around the periphery of the latter in predetermined locations suitable for causing said sensor to change state during a rotation of the moving element. These actuating elements can be simple teeth secured to the movable assembly and having a common trajectory passing through said space. Each tooth is thus capable of interrupting the beam crossing the space between the transmitter and the receiver. These changes in the state of the sensor, expected at well-determined angles of rotation of the moving assembly make it possible to check both its direction of rotation (for example during an initialization phase of the device, at power-up) and the smooth running of the rotation itself.

The invention will be better understood and other advantages thereof will appear more clearly in the light of the following description of a sheet processing device in accordance with its principle, given solely by way of example and made in reference to the accompanying drawings in which:
- Figure 1 is a partial schematic perspective view illustrating an office machine equipped with the sheet processing device according to the invention;
- Figure 2 is a section II-II of Figure 1, the sheet processing device being shown during a first phase of operation;
- Figure 3 is a view along arrow III of Figure 1, the device being in the same operating phase as in Figure 2;
- Figure 4 is a section II-II of Figure 1 when the sheet processing device is in a second operating phase;
- Figure 5 is a view along arrow III of Figure 1 with the device in the same operating phase as in Figure 4;
- Figure 6 is a view along arrow III of Figure 1 with the sheet processing device during a third operating phase;
- Figure 7 is a graph illustrating the changes of state of the detector during a rotation of the movable assembly from one treatment position to another, more precisely a reversal from the front position to the back position;
- Figure 8 is a view along arrow III of Figure 1 with the processing device during a fourth phase of operation, abnormal;
- Figure 9 is a graph showing the state of the detector during an operating anomaly during the rotation of the moving element;
- Figure 10 is a view along arrow III of Figure 1 with the sheet processing device in a fifth operating phase;
- Figure 11 is a view along arrow III of Figure 1 with the sheet processing device in a sixth operating phase;
- Figure 12 is a block diagram of an electronic control system of the device of Figure 1;
- Figures 13, 14, 15 and 16 show a flowchart illustrating the operation of the device under the control of the electronic system of Figure 12; and
- Figure 17 shows a flowchart illustrating the initialization of the positioning of the mobile assembly vis-à-vis the access arrangements that surround it.

 The office automation machine described here is a "scanner" for the development of digital information representative of a graphic carried on a sheet. It is a duplex scanner and therefore, the machine includes a sheet processing device allowing it to scan such a sheet 12 on its two faces. The device comprises for this purpose a movable assembly 13 mounted to rotate relative to a housing forming a support 15, around a main axis of rotation O and driven in rotation by drive means constituted here by an M5 motor, of the pitch type. step by step.

 In FIG. 1, the upper part of the mobile assembly 13 has been removed for a better visualization of the elements thereof. The mobile assembly houses a processing unit 14, namely here a read head in the form of a bar extending essentially parallel to the axis of rotation O. Drive rollers 16, 16a, 17, 17a are arranged inside the moving assembly on either side of the bar. They are arranged in parallel pairs, a roller of each pair being driven by the same motor M2 via drive wheels 18. A pressing means 19, in the form of a flexible blade is placed opposite the processing unit for apply a moving sheet against it. The drive rollers 16, 17 actuated by the motor M2 participate in the driving of a sheet during its journey through the moving element. This also includes a guide arrangement 218, 21k defining for such a sheet 12 a treatment path 23 passing opposite the treatment unit. The moving element can essentially take two predetermined, stable treatment positions, respectively shown in FIGS. 4 and 11. These two treatment positions correspond respectively to a treatment of the sheet on the front side then on the back side. The moving element 13 is substantially cylindrical.

 The housing forming a support 15 carries the motor M5 and also constitutes the support for the sheet access arrangements, external to the moving element. From these, there is an input means 25, an input-output means 27 and an output means 29. The input means 25 is equipped with a sheet presence detector 26. The means of input 25 and output means 29 are arranged side by side on one side of the moving element 13 while the input-output means 27 is located here on the other side of the moving element the lower part of the housing 15. The input means 25 comprises two parallel drive rollers 30, 30â, one of which is driven in rotation by a stepping motor M1, the outlet means comprises two drive rollers 31 , 31a parallel one of which is driven in rotation by a stepping motor M4 and the input-output means 27 comprises two driving rollers 32, 32a parallel one of which is driven in rotation by a stepping motor not M3. Fixed guides are defined in the housing near these access means for directing the sheet in the direction of the guide arrangement 21a. 21b defined in the moving element or to facilitate the extraction of such a sheet from this moving element. For each access means, the two drive rollers are practically in tangential contact so that a sheet can be introduced between them and driven in displacement.

 For each stable treatment position, guides of certain access means are therefore in the extension of a guide arrangement defined in the movable assembly. Operating anomalies result from the fact that a sheet still remains partially engaged in the moving assembly when the motor M5 is driven to move it from one treatment position to another.

 At the lower part of the housing 15 constituting the support of the movable assembly and in the vicinity of an axial end thereof, there is installed a sensor 36 capable of assuming two predetermined states as a function of external stress. In this case, this sensor comprises a transmitter 37 and a receiver 38 facing each other and separated by a space 39.

 In the example, and in a manner known per se, The emitter 37 is a light source while the receiver 38 is a photosensitive cell. Consequently, if an opaque element is introduced into said space 39, the receiver changes state. Typically, the photosensitive sensor delivers a DC voltage, for example a low value which will be denoted below 0, when the light beam crosses said space 39 and a high value which will be denoted below 1 when this beam is cut by an opaque element crossing the same space.

 It should be noted that this single sensor makes it possible, in conjunction with actuating elements carried by the moving element 13, to manage the rotations of this moving element and to detect certain operating anomalies.

 To do this, the moving element 13 comprises a first feeler 40 for detecting the presence of sheets placed in the vicinity of an inlet E of the guide arrangement. Indeed, whatever the treatment position taken by the moving element, a sheet will always penetrate into the moving element by this side. Said first feeler 40 is linked by a rod 41 to a first actuating element 43 of the sensor, pivotally mounted at one end of the movable element 13. This first actuating element forms a double flap capable of penetrating into said space 39 of the sensor, in certain circumstances and for certain positions of the moving assembly.

 More specifically, this actuating element 43 comprises a first part 45 in the form of a pivoting flap, which is in a position to cooperate with the sensor, that is to say capable of engaging in the space 39, when the moving element is in its first treatment position, that is to say the front treatment position illustrated in FIG. 3 in particular.

In this processing position, said first part 45 can pivot when it is driven by the probe 40 to take the position illustrated in FIG. 5.

 The first actuating element 43 is biased by a spring 44 in the position of FIG. 3 and can only assume the position illustrated in FIG. 5 if a sheet 12 is in contact with the probe 40, that is to say tell when such a sheet passes through the processing unit.

 The same first actuating element comprises a second part 47 also in the form of a pivoting flap, in position to cooperate with the sensor when the moving element is in a second treatment position, that is to say the treatment position. back illustrated in figure 10.

However, the arrangement is reversed since said second part 47 is capable of causing the sensor to pass from the second state (cut beam) to said first state when the probe is actuated by the passage of a sheet along the processing path. This change of state can be understood by comparing FIGS. 10 and 11. In FIG. 10, the mobile assembly is in the reverse processing position but no sheet passes through it, while in FIG. 11,
The moving element is in the same treatment position but a sheet 12 passes through it, comes into contact with the probe 40, makes the flap pivot and keeps it out of the sensor 36 as long as it is in contact with the probe.

 In other words, in the front operating position, the actuating element 43 passes the sensor from O to 1 when a sheet passes, while in the back operating position, the actuating element 43 passes the sensor from 1 to 0 when a sheet crosses the moving element.

 In addition, the sheet processing device comprises a second actuating element 48 acting on the same sensor, pivotally mounted at the end of the movable assembly 13 and resiliently biased, here by a spring 49, in order to be able to project towards outside the moving assembly and thus cause the state sensor 36 to change.

 However, when the moving element is in said first treatment position (front), this second actuating element 48 is in a retracted position (FIG. 3) in the vicinity and outside of the space 39 constituting the sensitivity zone of the sensor. .

 To do this, said second actuating element cooperates with a fixed stop 53, in said first treatment position of the moving assembly; this stop keeps it in the retracted position. More precisely, this second actuating element which comprises a part forming a flap more particularly capable of engaging in the space of the sensor, is integral with a rod 51 which extends longitudinally in the movable assembly and which comprises, at its end, a tab 52, perpendicular to the axis of the rod and capable of coming to bear against the fixed stop 53 secured to the housing.

When the tab 52 actually bears on this fixed stop in said first treatment position, the second actuating element 48 is retracted inside the movable assembly.

 On the other hand, as soon as the latter begins its rotation towards said second treatment position (back), the tab 52 ceases to be in contact with the fixed stop (FIG. 6) and the second actuating element pivots outwards from the moving part and engages for a moment in the space 39 of the sensor.

 Consequently, the latter emits a pulse P1 of confirmation of the effective rotation of the moving equipment; this is the first pulse from the left, shown in the graph in Figure 7.

 On the other hand, the rod which carries said second actuating element is linked to a second feeler 54 for detecting the presence of a sheet, here constituted by four parallel projections attached to said rod and regularly spaced along the latter. This second probe 54 is placed in the vicinity of an outlet S of the guide arrangement of the movable assembly, that is to say opposite to the first probe 40. The mounting is such that the second element d actuation 48 remains in the retracted position as long as a sheet is in contact with said second probe, as can be seen in particular in FIG. 8. On this one, it can be seen that a sheet has not been completely evacuated from the mobile crew even when it has started to rotate. This operating anomaly is detected by the fact that said second actuating element remains in the retracted position although the tab 52 has already left the fixed stop 53.

 In fact, the sheet 13 remains in contact with said second sheet presence detection probe, which keeps the second actuating element in the retracted position. Consequently, the confirmation pulse P1 is not emitted and such an event is taken into account by the system as being representative of an operating anomaly. This is illustrated in Figure 9; the sensor 36 does not deliver a level 1 at the angular position Z1 (very close to ZO) where the pulse P1 should appear. This results in the emission of an error message and the command to stop the motor M5 from the start of the rotation of the moving assembly, which makes it possible not to damage the sheet. In other words, the device includes means for generating at least one alarm signal if said second actuating element 48 remains in the retracted position when said moving element 13 leaves said first processing position.

 Finally, other actuating elements 54a-54e are capable of cooperating with the sensor. They are distributed around the periphery of the moving element in predetermined locations capable of causing the sensor 35 to change state during a rotation of the moving element 13.

 In the example, these other actuating elements are opaque teeth secured to the movable assembly, having a common trajectory passing through the space 39 of the sensor. Each tooth is thus capable of interrupting the beam passing through said space between the emitter and the receiver. These teeth therefore cause the development of P2 - P6 pulses, expected at predetermined angles of rotation of the moving element and which make it possible to check both the direction of rotation and the proper progress of this rotation. Thus, during a rotation from the front position to the back position, the two teeth 54a, 54b cause the two pulses P2, P3 which follow the start confirmation pulse P1 and then the three teeth 54, 54d, 54e cause subsequently three pulses P4, P5, P6 before the second part 47 of the first actuating element changes the output of the sensor to 1 (pulse P7) when the moving element reaches the second treatment position (back) and before reintroduction sheet 13 in the moving assembly. When the sheet is reintroduced into the movable assembly to undergo its treatment on the back side (FIG. 11) it comes into contact with the probe 40, which once again pivots said first actuating element and switches the sensor to 0 During the return to the back position, the sensor 36 first emits three pulses due to the teeth 54e, 54d, 54c then, two pulses due to the teeth 54b, 54a and finally a last pulse before arriving in the recto processing position, due to the second actuating element 48. Finally, when the tab 52 comes into contact with the fixed stop, the output of the sensor 36 drops to 0.

FIG. 12 illustrates schematically and in a simplified manner an electronic system intended to be associated and to control the operation of the sheet processing device described above. This electronic system mainly comprises, linked together by an address and data bus 116:
a central processing unit 111,
- a random access memory 112,
- a read only memory 113,
an input-output port 114 used to receive the information entered on a user interface 119 or supplied by the processing unit 15 itself or by the detectors 25 and 36. It also makes it possible to transmit control signals to the different motors M1, M2, M3, M4 and M5 via a power interface 117. The same input-output port 114 makes it possible to control the processing unit 14 (here the read head) installed in the mobile assembly and control the user interface 119, in particular for displaying the functions. The random access memory 112 receives and stores the information resulting from the processing of the sheets in the case of a scanner (it would receive and store the information necessary for the implementation of this processing in the case of a printer). It communicates via a parallel port 114 'with a PC operating system such as a computer where said information can be transferred or processed. It also includes a special register 112ê in which the operating parameters of the processing unit are kept. A portion 118 of the read-only memory 113 is adapted to keep the operating program of the central processing unit 111 and, in particular, the processing procedures explained by the flowcharts of FIGS. 13 to 17. The central processing unit 111 is suitable for implementing these flowcharts.

 In the remainder of the text, the "steps" designate the electrical pulses applied to a particular stepper motor and not the rotation which results from the application of these "electrical steps". On the other hand, PAS designates a counter intended to count the number of electric steps during operation 121, the motor M1 is set in motion in order to introduce the sheet along the path 23. A second test 122 controlled by the detector 36 is implemented. This test checks whether the output of detector 36 goes to 1 (Figure 5). As long as the test 122 is negative, we go back to operation 121. As soon as it becomes positive, the motor M2 is started in addition to the motor Mi, from X1 not to drive the sheet towards the processing unit and bring its leading edge opposite the latter, that is to say more precisely at the processing location identified by T in FIG. 2.

During operation 124, the processing of the sheet is implemented, the rotation of the motors M1 and M2 continues then the motor M3 of the input-output means 27 is started in the direction 1. The motors M1 and
M2 continue to be ordered.

 A test 125 determines whether the detector 36 still perceives the presence of the sheet, that is to say its state is 1. As long as the result of the test 125 is positive, it is repeated. As soon as the test 125 becomes negative, that is to say when the part 45 leaves the space 38, this means that the trailing edge of the sheet has left the probe 40. Then, the operation 126 consists in run the motor M3 in direction 1 of X2 not so that the trailing edge of the sheet leaves the treatment location. During operation 126, the processing of the sheet continues. The M2 motor continues to rotate.

 Test 127 consists in taking into account the selection of the processing mode of the single-sided mode or of the two-sided processing mode, programmed by an operator on the control panel of the machine.

If the single-sided mode has been chosen, the sheet is definitively ejected by the input-output means 27 during operation 128. For this, the motor M3 always rotates in the direction 1 of (Y1 MAX + ss) not ; "Yl
MAX step "corresponds to the distance between the processing location T and the input-output means while ss step corresponds to an additional displacement of the input-output means, sufficient to release the trailing edge of the sheet. The M2 motor continues to rotate.

 On the contrary, if the duplex mode has been selected, operation 129 is implemented which consists in actuating the motor M3 in the direction 1 of (Y1 MIN +) steps; "Y1 MIN step" corresponds to the distance between the processing location T and the outlet of the moving assembly while "y step" corresponds to a predetermined additional displacement of the trailing edge of the sheet, sufficient not to hinder the subsequent rotation of the moving part. In this case, the sheet is retained between the rollers 32 and 32a, in the vicinity of its trailing edge.

For the correct understanding of the flowcharts in Figures 14 to 17, it is necessary to define the following parameters:
- "A" is a counter used to memorize the number of passages of the detector 36 from level 0 to level 1,
- "B" is a counter used to memorize the passage of the detector 36 from level 1 to level 0,
- "Z" is a number of steps of the motor M5 causing the rotation of the moving assembly. This motor can rotate in two directions. Direction 1 makes it possible to rotate the moving element 13 anticlockwise by considering the drawings. Direction 2 makes it possible to rotate the moving element clockwise.

In FIG. 7, the values Z0 - Z13 of the variable Z indicate numbers of steps corresponding to remarkable intermediate positions of the moving element 13 throughout its rotation from a front position to a back position (direction 1) . In particular:
- ZO corresponds to the front processing position of the moving assembly, when no sheet is present,
Z1 corresponds to the position of the moving element where the second actuating means 48 is inside the space 38 of the detector, in the inversion phase and without any operating anomaly,
Z2 corresponds to the position of the moving element where the actuating element 48 has just left the detector 36,
Z3 corresponds to the position of the moving assembly where the tooth 54a is inside the detector 36,
Z4 corresponds to the position of the moving assembly where the tooth 54a has just left the detector 36,
Z5 corresponds to the position of the mobile assembly where the tooth 54b is inside the detector 36,
Z6 corresponds to the position of the mobile assembly where the tooth 54k has just left the detector 36,
Z7 corresponds to the position of the mobile assembly where the tooth 54c is inside the detector 36,
Z8 corresponds to the position of the moving assembly where the tooth 54c has just left the detector 36,
Z9 corresponds to the position of the mobile assembly where the tooth 54d is inside the detector 36,
Z10 corresponds to the position of the mobile assembly where the tooth 54d has just left the detector 36,
Zl 1 corresponds to the position of the mobile assembly where the tooth 54e is inside the detector 36,
Z12 corresponds to the position of the mobile assembly where the tooth 54e has just left the detector 36,
- 213 corresponds to the rear processing position of the moving element where the second actuating element 48 is inside the detector 36 when no sheet is present.

 In FIG. 14, which represents the reversal of the crew from the front position to the back position, the operation 130 consists in zeroing the counters "PAS", "A" and "B".

 In operation 131, the motor M5 is actuated by one step, in the direction 1, which has the effect of rotating the moving element 13 in the direction of the arrow F in FIG. 6. By the rotation of the moving element 13, the tab 52 being held against the stop 53, the rod 51 pivots making the second actuating element 48 enter the space 38 of the detector 36. In operation 132, the counter "PAS" is incremented by one.

 A test 133 determines whether the value of A is strictly greater than zero. As long as this condition is not fulfilled, and the number of steps of the motor M5 has not reached the value Z1 during test 134, we return to operation 131. When the Z1 steps are reached, we measure the state of the detector 36 by a test 135. If the detector 36 is at 1, that is to say if the second actuating element 48 is inside the detector, the counter A is incremented by unit in operation 136 and takes the value 1. We then return to step 131.

 If test 135 is negative, and if a sheet is still present inside the movable assembly, the probe 37 is blocked by said sheet and the second actuating element 49 is located outside the detector, which presents a state O. This is the situation illustrated in FIG. 8. We then go to step 137 where the procedure is immediately stopped and a message is sent to the user indicating to him the abnormal presence of paper inside. of the moving crew.

 Furthermore, after step 132, a test 133 checks whether A is greater than zero. This is normally the case after going to operation 136.

Consequently, in the affirmative, we pass to a test 138 which checks whether the value of A is greater than 7.

 If test 138 is negative, we pass to test 139 which checks whether "B" is requested equal to 1. "B" takes this value only if during tests 140, 141, 142, 143, 144 and 145, the engine M5 having turned from Z3 steps, Z5 steps, Z7 steps, Z9 steps, Z11 steps and 213 steps, respectively, the test 155 verifying whether the level of the detector 36 is at 1 is validated. In this case, in operation 156, A is incremented and B takes the value 1. We then go back to operation 131. On the other hand, if all tests 140 to 145 are negative, we go back directly to operation 131 If the test 155 is negative, we go to operation 154 which consists in displaying an operating anomaly message concerning the overturning of the moving equipment. Note that A determines the number of times that the detector 36 has been actuated (closed) successively by the second actuating element 48, the teeth 54 ?, 54t, 54ç, 546, 54e and finally by said first actuating element 43. Consequently, when the counter A reaches the value 7, this means that the moving element 13 has normally reached the back position and the back processing procedure, described below, can begin. An additional verification is carried out by associating the value of A with the number of steps taken by the motor M5, that is to say the value of the PAS counter, this in order to avoid possible step jumps. Consequently, when the counter A reaches the value 7, this indicates the end of the reversal of the moving assembly and we pass to the beginning of the reverse processing mode.

 As long as the test 139 is positive, the tests 146, 147, 148, 149, 150 and 151 in cascade, make it possible to request the value of the detector 36, during the test 152 knowing that the motor M5 has respectively run from Z2 steps, Z4 steps, Z6 steps, Z8 steps, Z10 steps and Z12 steps. If the value of the detector 36 is equal to 1, then this means that there is an anomaly in the rotation of the moving element and we go to step 154. On the other hand, if the test 152 is negative, B is set to zero in operation 153 and we return to operation 131.

 It is noted that the counter B makes it possible to ensure the transition of the value of the detector 36 and consequently of the effective rotation of the moving element.

 In Figure 15, there is shown the flow diagram of the treatment process in the back position. This begins with the operation 160 of starting the motor M3 in the direction 2, that is to say the direction which drives the input-output means 27, so that the sheet is reintroduced into the moving crew. The trailing edge then becomes the leading edge. This edge is directed again towards the probe 40 which makes the said actuating element pivot in a direction tending to release the part 47 of the space 38. The test 161 determines whether the detector 36 is at 1. As long as the result of test 161 is positive, it is repeated. As soon as the result of test 161 becomes negative, we go to operation 162 where the motor M2 is driven by a number of steps X1 to bring the leading edge of the sheet opposite the processing location T. The motors M1 and M3 are assumed to be identical in the example.

Meanwhile, the motor M3 continues to rotate. In operation 163, the processing of the sheet is implemented and the motor M4 is controlled to drive the output means 29 and allow the sheet to be evacuated.

 A test 164 then determines whether the detector 36 is in its state 1.

As long as the result of test 164 is negative, the test is repeated and processing continues. As soon as the result of the test 164 becomes positive, the motor M3 is stopped at operation 165. During operation 166, the motor M2 rotates by the number of steps X2 so that its trailing edge leaves the processing location . During operation 166, the processing of the sheet continues.

 In operation 167, the motor M2 is driven by X3 steps while the engine M4 is driven by Y2 not sufficient to bring out the sheet of the moving element and eject it by the output means 29. In operation 168, the motors are stopped and the end of the reverse processing mode is displayed, then we go to the beginning of the phase of reversing the moving element from the back position to the front position as illustrated in FIG. 16. This mode turning is very similar to that which has been described with reference to Figure 14 for the transition from the front processing position to the back processing position. It will therefore not be described in detail. The operations 170 to 172 correspond to the operations 130 to 132. It will however be noted that no detection of "jamming" of the sheet at the output of the moving assembly is provided (corresponding to tests 133 to 137 of FIG. 14) when it is in the reverse processing position. In fact, in view of the configuration of the device, there is little risk that this outlet will be blocked by an obstacle which would prevent the sheet from coming out. This is due to the fact that it is necessary to have a free location at the entrance to the device for the insertion of the sheet. As the exit is above the entrance, it benefits from this free location. Consequently, after operation 172, we pass directly to test 174 which corresponds to test 138 in FIG. 14. When this test is positive, this means that the inversion is finished and that we are again in the front processing position. .

 As long as test 174 is negative, we go through test 175 corresponding to test 139 which leads either to tests 176 to 182 (corresponding to tests 140 to 145) or else to tests 185 to 190 (corresponding to tests 146 to 151).

 Obviously, the contents of these tests are different since we start from position Z13. Test 191 and operation 192 correspond to test 152 and operation 153 while test 183 and operation 184 correspond to test 155 and operation 156. However, the outputs of tests 183 and 191 are inverted compared to those of tests 155 and 152. In other words, an anomaly of reversal of the moving assembly is detected if the test 191 is negative or if the test 183 is positive.

 A description will now be given with reference to FIG. 17 of a procedure for initializing the mobile equipment applicable, in particular when the office automation machine is put into service or put back into service following an incident. In such a case, it is necessary to correctly position the mobile assembly 13 in order to place the inlet E in the vicinity and in the extension of the inlet means 25.

 When the mode of initialization of positioning of the moving element 13 is launched by the central unit 111, the counter PAS is initialized at zero and the variable C takes the value of the detector 36 (operation 70).

 The first part of the initialization sequence, which corresponds to operations and tests 71 to 81, makes it possible to determine whether a sheet is present along the path 23 of the moving assembly 13.

 A first test 71 checks whether the detector 36 is at 1.

If this is the case, this means that the moving part may be in the front position with a sheet inside of it. During operations and tests 72 to 76, the motor M3 is started in direction 1 (that is to say the direction capable of driving the sheet towards the outside of the moving assembly) while the Ml and M2 motors are also started. These motors are started for a maximum number of steps
A0, A0 corresponding to the longest sheet length that can be used in the machine. At each step taken, the value of the variable C is compared with that of the detector 36. If this value changes, this means that a sheet was indeed present in the moving element 13 in the front position. The sheet is then ejected without fail by causing the motor M3 to spin in direction 1 and the motor M2 of (Y1 MAX + ss) steps. The device is ready to be fed by another sheet. More specifically, the test 71, if it is positive, leads to step 72 where the motors M1, M2 and M3 are controlled by one step (M3 in the direction 1).

In step 73, the PAS counter is incremented by one. We then go to test 74 which consists in comparing if the value "C" is always equal to the state of the detector 36. If so, we go to test 75 which checks if PAS is equal to A0. If this is not the case, we return to step 72. If this is the case, the PAS counter is reset to zero in step 77. If the result of test 74 is negative, we go to l 'step 76 which controls the motors M3 and M2 of (Y1 MAX + ss) steps and we arrive at the front reading mode.

On the other hand, if the test 71 is negative, this means that the mobile assembly can be in the back position with a sheet inside. During operations and tests 78 to 82, the motors M1, M2 and M3 (the latter in direction 2) are started for a maximum number of steps of A0. At each step taken, the value of C is compared with that of the detector 36. If it becomes different, this means that a sheet was present in the moving element 13 in the back position. The sheet is then ejected by turning the M2 motors and
M4 of X2 and X3 respectively. The moving element is then commanded to pass from the back position to the front position, which completes the initialization of the positioning of the moving element in this case. More specifically, in step 78, the motors M2, M3 and M4 are actuated by one step. Step 79 consists in incrementing the PAS counter by one. We then pass to test 80 which consists in comparing the variable C with the state of the detector 36. If this state is the same, we pass to test 82 which consists in comparing the variable PAS with the value AO. If this test is negative, we go back to step 78. If it is positive, we go to step 77. If test 80 is negative, we start the motors M2 and M4 of X2 and X3 not respectively , in step 81. We then pass to the mode of turning over of the moving assembly, towards the front position.

 In the case where no sheets have been detected inside the moving element, this leads to step 77 where the PAS counter is reset to zero.

 Operations 83 to 87 then take place; they make it possible to determine the angular position of the moving element 13. To do this, we will seek to locate the greatest distance between two consecutive teeth 54a-54e, on the circumference of the moving element, within the limits of the angle a, visible in figure 3, between the detector and the part 47. The numbers of steps of the motor M5 are indicated by the values Z1 - Zn on the graph of figure 7. The greatest distance between the consecutive teeth 54b and 54ç corresponds to a rotation of Z7 - Z6 steps.

 In operation 83, the motor M5 is started in direction 2 to cause the moving assembly 13 to rotate clockwise by considering the drawings.

The motor M5 must therefore rotate in direction 2 during Z7 - Z6 not without the value of the detector 36 changing. As long as this condition is not reached (test 85), the variable C is made equal to the value of detector 36 (operation 86) and we return to operation 83. As soon as test 85 becomes positive, we pass to test 87 which determines if the variable PAS is equal to
Z7 - Z6. If not, we go back to operation 83. If so, we go to operation 88 where the motor M5 is started in direction 2 of Z5 - Z6 not. We then go to test 89 which determines whether the detector 36 is at 1.

The operations 88 and the test 89 make it possible to determine whether the detector 36 is between the teeth 54b and 54c or whether it is outside the part of the moving assembly identified by the angle a.

 If the moving element is between the teeth 54b and 54c, the rotation of the motor M5 is controlled in the direction 2 of ZO - Z5 not in order to position the moving element in the position of treatment recto in operation 91.

It is then ready to operate in the front position.

 On the other hand, if the detector 36 is outside the part of the moving assembly identified by the angle a, the motor M5 is controlled in rotation in direction 1 until the detector 36 takes the value 1. This is achieved by operation 90 and test 92. As long as test 92 is negative, we return to operation 90 which increments the motor M5 by 1 step. As soon as the test 92 is positive, this means that the detector 36 takes the value 1 when the second actuating element 48 has just entered the space 38 of the detector. We then go to step 93 which consists in starting the motor M5 in the direction 2 of a number of steps equal to ZO - Z1 - W to place the moving assembly in the front-facing processing position. W pitch corresponds to a predetermined angle depending on the position of the second actuating element 48 with respect to the position of recto treatment. The moving part is then in the front processing position.

 As a variant, the teeth 42a - 42e could be of different widths, which would make it possible to know more quickly the position of the mobile assembly, in particular during a positioning initialization phase.

 It is also possible to complete the device with a second row of teeth (similar to teeth 54) cooperating with a second sensor, these teeth being in opposition with those previously described. This would immediately differentiate the treatment positions (front and back) of the mobile assembly from the intermediate positions of the latter. The initialization phase would be simplified and would last less time.

 The device which has just been described is equipped with a read head.

 It is therefore incorporated into an office machine which essentially constitutes a document scanner or a fax machine. However, it has already been indicated that the processing device could comprise at least one printing means, for example of the thermal transfer type or else an ink jet printing head. In this case, the office machine essentially constitutes a printer, possibly that of a fax machine. The sheet processing device is advantageously equipped with means for connection to a computer; it can also be part of a microcomputer.

Claims (24)

 1- Sheet processing device comprising:  - a mobile assembly (13) rotatably mounted on a support and housing a processing unit and a sheet guide arrangement defining for the latter a processing path passing opposite said processing unit, said mobile assembly being able to take two positions predetermined processing,  - at least two sheet access arrangements (25, 27, 29) arranged at predetermined locations on the periphery of said movable assembly and integral with said support,  a first feeler (40) for detecting the presence of a sheet carried by said mobile assembly,  - a sensor (36) mounted on said support and capable of assuming two predetermined states,  characterized in that said first probe (40) is linked to a first actuating element (43) of said sensor, mounted movably on said movable assembly and in that said first actuating element comprises a first part (45) in position to cooperate with said sensor (36) only when the mobile assembly is in a first treatment position, said first part being capable of causing said sensor to change state when said probe is actuated by a sheet (12).  2- Device according to claim 1, characterized in that said first actuating element (43) comprises a second part (47) in position to cooperate with said sensor only when the mobile assembly is in a second treatment position, said second part being able to change the state of said sensor when said probe is actuated by a sheet (12).  3- Device according to claim 2, characterized in that said first actuating element (43) is arranged to change said sensor from a first state to a second state when said movable assembly (13) is in said first position processing and that said first probe (40) is actuated and for passing said sensor (36) from said second state to said first state when said moving element (13) is in said second treatment position and that said first probe (40) is actuated .  4- Device according to one of the preceding claims, characterized in that said sensor (36) comprises a transmitter (37) and a receiver (38), in that a sensitivity space (39) of the sensor, in the vicinity of the latter, may be crossed by a beam delivered by the transmitter and in that said first actuation space (43) is a pivoting flap capable of acting on said beam, the or each part of said first actuation element forming a flap located respectively at least in the vicinity of said space when said moving element (13) is in one or the other of its processing positions so as to be able to change the state of said sensor when said first probe is actuated by leaf.  5- Device according to claim 4, characterized in that said transmitter (37) and said receiver (38) are placed opposite one another and separated by said space (39).  6- Device according to one of the preceding claims, characterized in that said feeler (40) for detecting the presence of sheet is placed in the vicinity of an inlet of said guide arrangement.  7- Device according to one of the preceding claims, characterized in that it comprises a second actuating element (48) of said sensor, pivotally mounted on the movable assembly and resiliently biased to protrude outwards from it ci so as to be able to change said state sensor and in that, when said moving element is in said first treatment position, said second actuating element is in a retracted position in the vicinity and outside of a zone of sensitivity of said sensor.  8- Device according to claim 7, characterized in that said second actuating element cooperates with a fixed stop (53) in said first treatment position of the movable assembly, which maintains it in the retracted position.  9- Device according to claim 7 or 8, characterized in that said sensor comprises a transmitter (37) and a receiver (38), in that a space of sensitivity of the sensor in the vicinity thereof, can be crossed by a beam delivered by the transmitter and in that said second actuating element (48) comprises a pivoting flap capable of acting on said beam.  10- Device according to one of claims 7 to 9, characterized in that said second actuating element (48) is linked to a second feeler (54) for detecting the presence of sheet carried by the movable assembly and placed at near an outlet (S) of said guide arrangement, the assembly being such that said second actuating element remains in the retracted position as long as a sheet is in contact with said second probe.  11- Device according to claim 10, characterized in that it comprises means for developing at least one alarm signal if said second actuating element remains in the retracted position when said moving assembly leaves said first processing position .  12- Device according to one of the preceding claims, characterized in that said movable element further carries other actuating elements (54â - 54fol) of said sensor distributed on the periphery of the movable element in predetermined locations suitable for changing the state of said sensor during a rotation of the moving element.  13- Device according to claim 12, characterized in that said sensor comprises a transmitter (37) and a receiver (39), in that a sensitivity space of the sensor in the vicinity thereof, can be crossed by a beam delivered by the transmitter and in that said other actuating elements are teeth (54S- 54) integral with the mobile assembly (13), having a common trajectory passing through said space, each tooth thus being capable of acting on said beam.  14- Device according to claim 4, 9 or 13, characterized in that, in a manner known per se, said sensor comprises a light source (37) and a photosensitive cell (38), for example arranged on either side of said space of sensitivity.  15- Device according to one of the preceding claims, characterized in that the aforementioned processing unit comprises a read head (14).  16- Device according to one of claims 1 to 14, characterized in that the processing unit comprises at least one printing means.  17- Device according to claim 16, characterized in that said printing means is of the thermal transfer type.  18- Device according to claim 16, characterized in that said printing means is an ink jet print head.  19- Office machine, characterized in that it comprises or is equipped with a sheet processing device according to one of the preceding claims.  20- Office machine according to claim 19, characterized in that it essentially constitutes a document scanner.  21- Office machine according to claim 19, characterized in that it essentially constitutes a fax machine.  22- Office machine according to claim 19, characterized in that it essentially constitutes a printer.  23- Office machine according to one of claims 19 to 22, characterized in that said sheet processing device is equipped with means for connection to a computer.  24- A microcomputer characterized in that it comprises at least one sheet processing device according to one of claims 1 to 18.