Abstract:
In an original-feeding device and method, originals are conveyed from an original-tray on which a bundle of originals can be mounted to an original-reading mount. A control unit controls an original-conveying operation so as to separate and feed originals from the bundle of originals mounted on the original-tray onto the original-reading mount either from an uppermost original or from a lowermost original. The control unit can control the original-conveying operation to juxtapose two consecutive originals on the original-reading mount irrespective of whether the originals are fed from the uppermost or lower-most original. In addition, the number of originals in the bundle can be counted if certain conditions exist.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates to an original-feeding device capable of separating and feeding the uppermost original of a bundle of originals, and capable of separating and feeding the lowermost original of the bundle. 
     2. Description of the Related Art 
     In conventional original-feeding devices, originals are sequentially fed only either from the first page or the last page. In an ordinary original-copying operation, the copying operation starts, in most cases, from the last page in consideration of ease in processing of copying sheets. 
     Recently, copiers also having a facsimile function have been realized. In this kind of copiers, originals must be processed from the first page when the facsimile function operates. Accordingly, automatic original-feeding devices for such copiers have been proposed in which, when the copier performs a facsimile operation, processing starting from the first page (feeding of upper originals) is performed, and when the copier performs an ordinary original-copying operation, processing starting from the last page (feeding of lower originals) is performed. 
     However, in the above-described conventional automatic original-feeding devices capable of performing two kinds of original-feeding operations, i.e., processing starting from the first page and processsing starting from the last page, it is impossible to perform control of an original-feeding operation which allows a duplex mode of performing copying or facsimile transmission of an original having printed images on both surfaces thereof, or a 2-in-1 mode of copying two originals on one copying sheet or performing facsimile transmission of two originals without providing an interval between the two originals to provide a situation as if a single original were transmitted. 
     When, for example, obtaining a duplex copy from a simplex original, it is necessary to know whether the number of originals mounted on an original-mounting tray is even or odd when starting processing from the last page. On the other hand, when starting processing from the first page, it is unnecessary to know whether the number of originals mounted on an original-mounting tray is even or odd even when reading both surfaces of a simplex original. Hence, it is wasteful to detect whether the number of mounted originals is even or odd for the latter case. 
     SUMMARY OF THE INVENTION 
     It is an object of the present invention to provide an original-feeding device which solves the above-described problems. 
     It is another object of the present invention to provide an original-feeding device in which, when performing control of an original-conveying operation so as to separate/feed a bundle of originals mounted on an original-tray onto an original-reading mount either from the upper-most original or from the lowermost original, the originals can be disposed on the original-reading mount in various forms, and the number of the mounted originals is not wastefully counted. 
     According to one aspect, the present invention which achieves these objectives relates to an original-feeding device in which originals are conveyed from an original-tray, on which a bundle of originals can be mounted, to an original-reading mount, comprising control means for controlling an original-conveying operation so as to selectively separate and feed originals from the bundle of originals mounted on the original-tray onto the original-reading mount either from an uppermost original or from a lowermost original, wherein the control means can control the original-conveying operation to juxtapose two consecutive originals on the original-reading mount irrespective of whether the originals are separated and fed from the upper-most original or from the lowermost original. 
     According to another aspect, the present invention which achieves these objectives relates to an original-feeding method of conveying originals from an original-tray to an original-reading mount, comprising the step of controlling an original-conveying operation so as to selectively separate and feed the originals from the bundle of originals mounted on the original-tray onto the original-reading mount either from an uppermost original or from a lowermost original, wherein the control step can include controlling the original-conveying operation to juxtapose two consecutive originals on the original-reading mount when the originals are separated and fed either from the upper-most original or from the lowermost original. 
     The foregoing and other objects, advantages and features of the present invention will become more apparent from the following detailed description of the preferred embodiment taken in conjunction with the accompanying drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a schematic diagram illustrating the configuration of an automatic original-feeding device (RDF (recycling document feeder)) according to an embodiment of the present invention; 
     FIG. 2 is a block diagram of a control circuit for controlling the automatic original-feeding device (RDF) shown in FIG. 1; 
     FIGS. 3(A)-3(E) are diagrams illustrating an original-conveying operation in a simplex-original/lower-sheet separation mode; 
     FIGS. 4(A)-4(H) are diagrams illustrating an original-conveying operation in a duplex-original/lower-sheet separation mode; 
     FIGS. 5(A)-5(G) are diagrams illustrating an original-conveying operation in a 2-in-1/lower-sheet separation mode; 
     FIGS. 6(A)-6(E) are diagrams illustrating an original-conveying operation in a simplex-original/upper-sheet separation mode; 
     FIGS. 7(A)-7(I) are diagrams illustrating an original-conveying operation in a duplex-original/upper-sheet separation mode; 
     FIGS. 8(A)-8(F) are diagrams illustrating an original-conveying operation in a 2-in-1/upper-sheet separation mode; and 
     FIGS. 9 and 10 are flowcharts illustrating an original-feeding operation in the embodiment. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     A preferred embodiment of the present invention will now be described with reference to the drawings. 
     FIG. 1 is a schematic diagram illustrating the configuration of an automatic original-feeding device (RDF) according to the preferred embodiment. 
     The automatic original-feeding device (RDF) includes an original-mounting tray 1, an original-stopper 2, a semicircular roller 3, a pickup roller 4, a separation motor 5, a feeding roller 6, separation rollers 7 and 8, a separation belt 9, a sheet feeding motor 10a, a sheet-feeding-clock-signal disc 10b, a sheet-feeding-motor-clock-signal sensor 10c, feeding rollers 11 and 12, a first discharging roller 13a, a second discharging roller 13b, a belt motor 14a, an electromagnetic brake 14b, a belt-clock-signal disc 14c, a belt-clock-signal sensor 14d, platen glass (also called an original-reading mount or original-glass) 15, a belt driving roller 16, a turn roller 17, a full-face belt 18, a recycle lever 19, a recycle-lever driving motor 20a, a recycle-lever-reference-position detection sensor 20b, a first discharged-sheet sensor 21, a registration sensor 22, an original-detection sensor 23, a reversal sensor 24, a second discharged-sheet sensor 25, a discharged-original-partitioning-lever-reference-position sensor 26, an original-size-in-conveying-direction detection sensor 27, a stamp solenoid 28, a discharged-original-partitioning-lever driving motor 29, a discharged-original partitioning lever 30, a separation sensor 31, an electromagnetic clutch 32, and a discharged-original tray 33. 
     By utilizing the above-described components, the automatic original-feeding device (RDF) can perform switching between an upper-sheet separation mode for individually conveying (feeding) a bundle S of originals mounted on the original-mounting tray 1 toward the original-glass 15 from the uppermost original (the first page), and a lower-sheet separation mode for individually conveying (feeding) the originals toward the original-glass 15 from the lowermost original (the last page), for the bundle S of originals. 
     Furthermore, the automatic original-feeding device (RDF) can perform switching among a simplex-original mode of performing a sheet feeding operation in order to read information of a simplex original having the information recorded only on one surface thereof, a duplex-original mode of performing a sheet feeding operation in order to read information of both surfaces of a duplex original having the information recorded on both surfaces thereof, and a 2-in-1 (juxtaposition) mode of performing a sheet feeding operation so as to juxtapose two originals on the original-glass 15 in order to read two (simplex) originals and record the read images of the originals on a single recording sheet. 
     The original-mounting tray 1 is disposed so as to incline downward in the original-feeding direction so that the bundle S of originals is mounted to be aligned in the original-feeding direction. In order to prevent skew of an original while the original is conveyed, an original-regulating plate (not shown) is provided on the original-mounting tray 1. An original-width-detection variable resistor (not shown in FIG. 1, discussed later in connection with FIG. 2) linked with the original-regulating plate is connected thereto, so that the width size of the original can be detected by detecting the voltage value corresponding to the position of the original-regulating plate. The original-size-in-conveying-direction detection sensor 27 is provided on the original-mounting tray 1. It is possible to determine in advance before starting an original-feeding operation if two originals can be juxtaposed on the platen glass 15, based on the size of the originals in the conveying direction detected by the original-size-in-conveying-direction detection sensor 27. 
     The semicircular roller 3 sequentially feeds the originals mounted on the original-mounting tray 1 from the lowermost original (the last page) to a separation unit provided at the downstream side. The semicircular roller 3 is controlled such that, when an original is present on the original-mounting tray 1 and feeding is to be done from the lowermost original, the semicircular roller 3 is rotated in the direction of the arrow. When there is no original on the original-mounting tray 1, and when sequentially feeding originals from the uppermost original (the first page) to the separation unit provided at the downstream side, the semicircular roller 3 stops its rotation with its notch portion placed up. 
     The recycle lever 19 is driven by the recycle motor 20a when starting an original-feeding operation, and is mounted on the uppermost original of the bundle of originals in order to discriminate between the last original to be fed and originals subjected to copying processing. When performing copying processing, since originals subjected to copying processing are returned to the original-mounting tray 1 and must be discriminated from the last original to be fed, the recycle lever 19 is driven. On the other hand, when performing facsimile transmission processing, since originals subjected to copying processing are discharged onto the discharged-original tray 33 without being returned to the original-mounting tray 1, the recycle lever 19 is not driven. 
     It is possible to perform precounting of the number of the originals mounted on the original-mounting tray 1, by executing a simplex-original conveying operation (to be described later) without performing a copying operation until it becomes clear that the last original has been conveyed, i.e., all originals have been conveyed. This is done by the detection by the recycle-lever-reference-position detection sensor 20b that the recycle lever 19 mounted on the bundle S of originals has dropped below the surface of the original-mounting tray 1. By notifying the counted number of the originals to the main body of the copier, the main body of the copier can appropriately perform, for example, processing to be performed when the number of originals is odd when, for example, obtaining a duplex copy from a simplex original. The counting of the number of mounted originals is performed only under specific conditions, which will be described later. 
     The pickup roller 4 improves conveyability of originals by being pressed against the bundle S of originals by the pickup-roller driving solenoid 4a (not shown in FIG. 1, see FIG. 2), and by being rotatably driven by the sheet feeding motor 10a. When sequentially feeding the originals from the lowermost original (the last page), the pickup roller 4 is not rotated, and when sequentially feeding the originals from the uppermost original (the first page), the pickup roller 4 is rotatably driven. 
     The separation unit comprises the feeding roller 6, the separation rollers 7, 8, and the separation belt 9 wound around the separation rollers 7, 8. The feeding roller 6 and the separation rollers 7, 8 are rotatably driven by the separation motor 5. When feeding the originals from the lowermost original (the last page), by rotatably driving the feeding roller 6 and the separation rollers 7, 8 in the direction indicated by the arrows in FIG. 1, the lowermost original is separated and fed from among a plurality of originals sequentially fed from the lowermost original (the last page). When feeding originals from the uppermost original (the first page), by rotatably driving the feeding roller 6 and the separation rollers 7, 8 in a direction opposite to the direction indicated by the arrows in FIG. 1, the uppermost original is separated and fed from among a plurality of originals sequentially fed from the uppermost original (the first page). 
     The original fed from the separation unit is grasped between the feeding rollers 11, 12, in pressure contact with each other, driven by the sheet feeding motor 10a, and is fed onto the platen glass 15 by the rotation of the feeding rollers 11, 12 in the directions of the arrows. At that time, by measuring the amount of pulses of the sheet-feeding-motor-clock-signal sensor 10c while the original conveyed by the feeding rollers 11, 12 passes through the registration sensor 22, the length of the original in the conveying direction can be detected. The sheet feeding motor 10a also drives the first discharging roller 13a and the second discharging roller 13b. 
     The full-surface belt 18 on the platen glass 15 is an endless belt having a width to cover the entire surface of the sheet-like original. The surface of the full-surface belt 18 has a sufficient coefficient of friction to convey the original in two directions by gliding it with the frictional force. The full-surface belt 18 is stretched between the driving roller 16 and the turn roller 17, and is configured to avoid slip between the full-surface belt 18 and the driving roller 16. The driving roller 16 is rotatably driven by the belt motor 14a. 
     The original conveyed onto the platen glass 15 is read and processed by the main body of the copier in order to perform copying processing or facsimile transmission processing. Thereafter, if subjected to copying processing, the original is returned onto the original-mounting tray 1, or, if subjected to facsimile transmission processing, the original is discharged onto the discharged-original tray 33. 
     When being returned onto the original-mounting tray 1, the original is discharged from the platen glass 15 by the movement of the full-surface belt 18 in the direction of an arrow A shown in FIG. 1. The original is conveyed by being grasped between the first discharging roller 13a and the feeding roller 12, in pressure contact with each other, rotating in the directions of the arrows. 
     When being discharged onto the discharged-original tray 33, the original is guided in the direction of an arrow B shown in FIG. 1 onto the discharged-original tray 33 by the full-surface belt 18. At that time, by driving the stamp solenoid 28 in response to an instruction from the main body of the copier, a &#34;read&#34; stamp is stamped on a predetermined position of the original to be discharged as a mark indicating completion of an original-reading operation. 
     The above-described original-conveying operation is repeated until all of the originals mounted on the original-mounting tray 1 are fed, or until an instruction to stop the original-conveying operation is provided. 
     FIG. 2 is a block diagram of a control circuit for controlling the automatic original-feeding device (RDF) shown in FIG. 1. 
     This control circuit controls various kinds of automatic original-feeding operations while exchanging signals with a controller C of the main body of the copier principally by the function of a single-chip microprocessor M. 
     That is, an original-feeding signal, an original-discharging signal, an operational-mode signal and a stampdepressing signal from the controller C of the main body of the copier are input to input ports I1-I3 and I14, respectively, of the microprocessor M via a line receiver 56. Signals from the registration sensor 22, the original-detection sensor 23, the first discharged-sheet sensor 21, the reversal sensor 24, the second discharged-sheet sensor 25, an RDF open/close sensor 35 (omitted in FIG. 1), the recycle-lever-reference-position detection sensor 20b, the original-size-in-conveying-direction detection sensor 27, the discharged-original-partitioning-lever-reference-position sensor 26 and the separation sensor 31 are input to input ports I4-I13, respectively, of the microprocessor M. 
     Respective encoder pulse signals from the belt-motor-clock-signal sensor 14d and the sheet-feeding-motor-clock-signal sensor 10c are input to interrupt terminals INT1 and INT2, respectively, of the microprocessor M. These encoder pulse signals serve as reference clock signals for the amount of movement of the fed sheet, and are counted by an internal counter of the microprocessor M. 
     A copying request signal, an original-detection signal, an original-size signal and an original-precount value are output from output ports O1-O3 and O14, respectively, to the controller C of the main body of the copier via corresponding drivers D. Operation signals for the separation motor 5, the belt motor 14a, the electromagnetic brake 14b, the sheet feeding motor 10a, the recycle-lever driving motor 20a, the electromagnetic clutch 32 (see FIG. 1), the stamp solenoid 28, the discharged-original-partitioning-lever driving motor 29 and the pickup-roller driving solenoid 4a are output from output ports O4-O12, respectively, of the microprocessor M via corresponding drivers D. 
     The operational-mode signal comprises three kinds of signals, i.e., a mode signal indicating upper-sheet separation or lower-sheet separation, a mode signal indicating one of a simplex original, a duplex original and 2-in-1, and a mode signal indicating whether or not the number of originals mounted on the original-mounting tray 1 is to be counted. 
     A ROM (read-only memory) 51 stores control programs represented by flowcharts shown in FIGS. 9 and 10, discussed later, and the like. A RAM (random access memory) 52 is utilized, for example, as operation areas for calculation. 
     An EEPROM (electrically erasable and programmable read-only memory 53) is provided as a nonvolatile memory. An A/D (analog-to-digital) converter 54 is provided for reading voltage values, and a D/A (digital-to-analog) converter 55 serves as output-voltage changing means. Each of these is connected to the microprocessor M as shown. An original-width-detection variable resistor 34, linked with the original-regulating platen provided on the original-tray 1, is connected to the A/D converter 54. By detecting the voltage value associated with the variable resistor 34, the width of the mounted original can be detected. 
     Next, a description will be provided of the original-conveying operation in each operational mode with respect to FIGS. 3(A) through 8(F). 
     FIGS. 3(A)-3(E) are diagrams illustrating the original-conveying operation in a simplex-original/lower-separation mode set mainly during copying processing. 
     Referring to FIG. 1, in a simplex-original/lower-sheet separation mode, originals mounted on the original-mounting tray 1 are sequentially fed from the lowermost original (the last page of the originals), and the fed original is mounted on the platen glass (original-glass) 15. After the image of the original on the platen glass 15 is read, the original is conveyed and discharged onto the original-mounting tray 1. FIGS. 3(A), 3(B), 3(C), 3(D) and 3(E) illustrate a state when an operation of feeding the original is started, a state during the original-feeding operation, a state in which an operation of mounting the original has been completed and an operation of reading the original is performed, a state in which an operation of discharging the original is started, and a state in which the original is being discharged, respectively. 
     In the simplex-original/lower-sheet separation mode, the number of originals mounted on the original-mounting tray 1 is, in some cases, counted. The counting of the number of the originals is performed by executing the original-conveying operation except the reading processing shown in FIG. 3(C) for all of the originals mounted on the original-mounting tray 1 before starting actual conveyance for the reading processing (the same holds in any other mode). 
     FIGS. 4(A)-4(H) are diagrams illustrating the original-conveying operation in a duplex-original/lower-sheet separation mode set mainly during copying processing. 
     As shown in FIGS. 4(A)-4(H), in the duplex-original/lower-sheet separation mode, originals mounted on the original-mounting tray 1 are sequentially fed from the lowermost original (the last page of the originals). In order to read both a first surface and a second surface of the fed original, the original whose first surface has been read is automatically reversed and then the second surface is read. 
     The originals mounted on the original-mounting tray 1 are sequentially fed from the lowermost original (the last page of the originals) (FIGS. 4(A) and 4(B)), the fed original is then reversed (FIGS. 4(C) and 4(D)) and is set so that the second surface can be read, and the second surface is read by the main body of the copier (FIG. 4(E)). After reading the second surface, the original is again reversed (FIG. 4(F)), and the first surface is set, and read by the main body of the copier (FIG. 4(G)). After reading the second surface, the original is discharged onto the original-mounting tray 1 (FIG. 4(H)). As shown in FIGS. 4(C) and 4(D), when reversing the original, a flapper 40 is set to the upper side. As shown in FIG. 4(H), when discharging the original, the flapper 40 is set to the lower side. 
     In the duplex-original/lower-sheet separation mode, number of the originals mounted on the original-mounting tray 1 is not subjected to precounting. As can be seen from FIG. 4(D) and the like, the state of the original in the longitudinal direction is not reversed from the state in which the original is mounted on the original-mounting tray 1. Here, the word &#34;reversed&#34; does not indicate a reversal of the state of the original in the longitudinal direction, but indicates a situation in which the original already conveyed onto the original-reading mount 15 is conveyed again onto the original-reading mount 15 while reversing the surface of the original which is exposed to the original-reading mount 15. 
     FIGS. 5(A)-5(G) are diagrams illustrating the original-conveying operation in a 2-in-1/lower-sheet separation mode set mainly during copying processing. 
     In the 2-in-1/lower-sheet separation mode, originals mounted on the original-mounting tray 1 are sequentially fed from the lowermost original, and two originals are simultaneously read. In order to perform the simultaneous reading operation, the first original P1 is reversed (FIGS. 5(A), 5(B) and 5(C)). In order to reverse again the placed first sheet, the first original is conveyed through a reversal path (the path of the first discharging roller 13a), and the second original P2 is also conveyed through another path (an ordinary path where reversal is not performed: the path of the feeding roller 11) (FIG. 5(D)). In this case, device is configured so that there is no interval between the leading edge of the first original P1 and the trailing edge of the second original P2 at the confluence of the two paths. 
     The first and second originals P1, P2 joined in the above-described manner are simultaneously read (FIGS. 5(E) and 5(F)), and are then returned onto the original-reading tray 1 in the sequence of the first original P1 and the second original P2 (FIG. 5(G)). 
     In the 2-in-1/lower-sheet separation mode, the number of the originals mounted on the original-mounting tray 1 is, in some cases, counted. 
     FIGS. 6(A)-6(E) are diagrams illustrating the original-conveying operation in a simplex-original/upper-sheet separation mode set mainly during facsimile transmission processing. 
     In the simplex-original/upper-sheet separation mode, originals mounted on the original-mounting tray 1 are sequentially fed from the uppermost original (the first page of the originals) (FIGS. 6(A) and 6(B)), and the fed sheet is mounted onto the platen glass (original-glass) 15 (FIG. 6(C)). After the image on the original has been read, the original on the original-glass 15 is conveyed (FIG. 6(D)), and is discharged onto the discharged-original tray 33 (FIG. 6(E)). 
     In the simplex-original/upper-sheet separation mode, the number of the originals mounted on the original-mounting tray 1 is not subjected to precounting. 
     FIGS. 7(A)-7(I) are diagrams illustrating the original-conveying operation in a duplex-original/upper-sheet separation mode set mainly during facsimile transmission processing. 
     In the duplex-original/upper-sheet separation mode, originals mounted on the original-mounting tray 1 are sequentially fed from the uppermost original (the first page of the originals), and a first surface of the first original is set (FIGS. 7(A), 7(B) and 7(C)), and is read (FIG. 7(C)). Then, the original is reversed and set (FIGS. 7(D) and 7(F)), and a second surface of the original is read (FIG. 7(E)). Then, the original is again reversed (FIGS. 7(F) and 7(G)), and is discharged onto the discharged-original tray 33 (FIGS. 7(H) and 7(I)). 
     In the duplex-original/upper-sleet separation mode, the number of the originals mounted on the original-mounting tray 1 is not subjected to precounting. 
     FIGS. 8(A)-8(F) are diagrams illustrating the original conveying operation in a 2-in-1/upper-sheet separation mode set mainly during facsimile transmission processing. 
     In the 2-in-1/upper-sheet separation mode, originals mounted on the original-mounting tray 1 are sequentially fed from the uppermost original (the first page of the originals), and the first fed original P1 is mounted (FIGS. 8(A) and 8(B)) and is then conveyed in a reverse direction by a predetermined amount to such a degree that the original does not reach the roller 12 (FIG. 8(C)). Then, the second original P2 is fed, and is stopped before the full-face belt 18, and a state in which no spacing is present between the trailing edge of the first original P1 and the leading edge of the second original P2 is provided (FIG. 8D)). Thereafter, by simultaneously driving the roller 12 and the full-face belt 18, the first and second originals are simultaneously conveyed onto and set on the original-glass 15 (FIG. 8(E)). The first and second originals P1, P2 are simultaneously read (FIG. 8(E)), and the two originals are then discharged onto the discharged-original tray 33 (FIG. 8(F)). 
     In the 2-in-1/upper-sheet separation mode, the number of the originals mounted on the original-mounting tray 1 is not subjected to precounting. 
     Next, a description will be provided of the original-conveying operation in the embodiment with reference to the flowcharts shown in FIGS. 9 and 10. 
     The microprocessor M first checks an operational-mode signal input from the controller C of the main body of the copier according to a program preset in the ROM 51, and determines if the lower-sheet separation mode is set (step S1). If the result of the determination in step S1 is affirmative, it is then determined if an original-feeding signal input from the controller C is &#34;on&#34; (step S2). If the result of the determination in step S2 is affirmative, the microprocessor M checks an operational-mode signal input from the controller C, and determines if the simplex-original mode is set (step S3). 
     If the result of the determination in step S3 is affirmative, the microprocessor M checks an operational-mode signal input from the controller C, and determines if a count mode is set (step S4). In a mode of performing copying on both surfaces of a recording sheet by the main body of the copier and automatically controlling the device so that no blank page is present before the page, the main body of the copier outputs a signal indicating that the count mode is set. If the result of the determination in step S4 is affirmative, the number of the originals mounted on the original-mounting tray 1 is counted by performing the conveyance control shown in FIGS. 3(A)-3(E) (the reading processing shown in FIG. 3(C) is not performed) (step S5). 
     In step S6, the microprocessor M determines if the counting of the number of the originals has been completed. If the result of the determination in step S6 is affirmative, the conveying processing in the simplex-original/lower-sheet separation mode shown in FIGS. 3(A)-3(E) is performed (step S7), and the process returns to step S1. If the result of the determination in step S4 is negative, the process proceeds to step S7 by skipping steps S5 and S6. In step S7, the conveying processing in the simplex-original/lower-sheet separation mode shown in FIGS. 3(A)-3(E) is performed. (However, the processing of discharging the read original onto the original-mounting tray 1 or the discharged-original tray 33 is not performed in this processing. The same holds for steps S9, S14, S19, S21 and S23 (to be described later)). 
     If the result of the determination in step S3 is negative, the microprocessor M then determines if the duplex-original mode is set (step S8). If the result of the determination in step S8 is affirmative, i.e., if the duplex-original/lower-sheet separation mode is set, the conveying processing in the duplex-original/lower-sheet separation mode shown in FIGS. 4(A)-4(H) is performed (step S9), and the process returns to step S1. That is, in the duplex-original/lower-sheet separation mode, it is unnecessary to know the number of the originals in advance because both surfaces of the original are read. Hence, the counting of the number of the originals is not performed irrespective of lower-sheet separation. 
     If the result of the determination in step S8 is negative, the microprocessor M then determines if the 2-in-1 mode is set (step S10). If the result of the determination in step S10 is affirmative, i.e., if the 2-in-1/lower-sheet separation mode is set, the microprocessor M checks an operational-mode signal input from the controller C, and determines if the count mode is set (step S11). In a mode of performing automatic control so that no blank page is formed before the first page, the main body of the copier outputs a signal indicating that the count mode is set. If the result of the determination in step S11 is affirmative, the number of the originals mounted on the original-mounting tray 1 is counted by performing the conveyance control shown in FIGS. 3(A)-3(E) (the reading processing shown in FIG. 3(C) is not performed) (step S12). 
     In step S13, the microprocessor M determines if the counting of the number of the originals has been completed. If the result of the determination in step S13 is affirmative, the count value is output to the controller C of the main body of the copier as a part of an original-detection signal, and the conveying processing in the 2-in-1/lower-sheet separation mode shown in FIGS. 5(A)-5(G) is performed (step S14), and the process returns to step S1. If the result of the determination in step S11 is negative, the process proceeds to step S14 by skipping steps S12 and S13. In step S14, the conveying processing in the 2-in-1/lower-sheet separation mode shown in FIGS. 5(A)-5(G) is performed. 
     Every time an original-feeding signal from the controller C is &#34;on&#34; in step S2, the above-described series of sheet feeding/discharging operations are repeated. The main body of the copier turns on an original-discharging signal when all of the originals have been fed from the original-mounting tray 1 of the RDF, or when the operation is interrupted by depression of a stop key. If an original-discharging signal is &#34;on&#34;, all read originals mounted on the platen glass 15 are discharged onto the original-mounting tray 1 (step S16), and the process returns to step S1. On the other hand, if an original-discharging signal is &#34;off&#34;, the process returns to step S2. 
     If the result of the determination in step S1 is negative, i.e., if the microprocessor M has determined that the upper-sheet separation mode is set, the microprocessor M then determines if an original-feeding signal input from the controller C is &#34;on&#34; (step S17). If the result of the determination in step S17 is affirmative, the microprocessor checks an operational-mode signal input from the controller C, and determines if the simplex-original mode is set (step S18). 
     If the result of the determination in step S18 is affirmative, i.e., if the simplex-original/upper-sheet separation mode is set, the conveying processing in the simplex-original/upper-sheet separation mode shown in FIGS. 6(A)-6(E) is performed (step S19), and the process returns to step S1. That is, the counting of the number of the originals is not performed in the simplex-original/upper-sheet separation mode. 
     If the result of the determination in step S18 is negative, the microprocessor M then determines if the duplex-original mode is set (step S20). If the result of the determination in step S20 is affirmative, i.e., if the duplex-original/upper-sheet separation mode is set, the conveying processing in the duplex-original/upper-sheet separation mode shown in FIGS. 7(A)-7(I) is performed (step S21), and the process returns to step S1. That is, the counting of the number of the originals is not performed in the duplex-original/upper-sheet separation mode. 
     If the result or the determination in step S20 is negative, the microprocessor M then determines if the 2-in-1 mode is set (step S22). If the result of the determination in step S22 is affirmative, i.e., if the 2-in-1/upper-sheet separation mode is set, the conveying processing in the 2-in-1/upper-sheet separation mode shown in FIGS. 8(A)-8(F) is performed, and the process returns to step S1. 
     Every time an original-feeding signal from the controller C is &#34;on&#34; in step S17, the series of sheet feeding/discharging operations are repeated. The main body or the copier turns on an original-discharging signal when all of the originals have been fed from the original-mounting tray 1 of the RDF, or when the operation is interrupted by depression of the stop key. If an original-discharging signal is &#34;on&#34;, all read originals mounted on the platen glass 15 are discharged onto the discharged-original tray 33 (step S25), and the process returns to step S1. On the other hand, if an original-discharging signal is &#34;off&#34;, the process returns to step S17. 
     As described above, in the present embodiment, by providing an original-reversal mechanism, it is possible to perform an original-conveying operation in the duplex-original/lower-sheet separation mode and in the 2-in-1/lower-sheet separation mode. When performing upper-sheet separation mainly in order to perform facsimile transmission processing, the counting of the number of originals is not performed at all. Even when performing lower-sheet separation in order to perform copying processing, the counting of the number of originals is not performed in the duplex-original mode. The counting of the number of originals is performed only in the simplex-original mode and in the 2-in-1 mode. That is, by counting the number of originals only when it is necessary to do the counting, the original-processing time period is shortened. 
     The individual components shown in outline or designated by blocks are all well known in the original-feeding device arts and their specific construction and operation are not critical to the operation or the best mode for carrying out the invention. 
     While the present invention has been described with respect to what is presently considered to be the preferred embodiment, it is to be understood that the invention is not limited to the disclosed embodiment. To the contrary, the present invention is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims. The scope of the following claims is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures and functions.