Sheet classifying apparatus and method

Abstract: A sheet classifying apparatus includes a supply section, a detecting section, a plurality of classifying boxes, a convey route and feed-out mechanisms, an assignment adjusting section, and a control section. The convey route and feed-out mechanisms automatically reset the sheets in the classifying boxes in the supply section in accordance with a predetermined classifying box order, thereby preparing for a second and following classifying operations. The adjusting section adjusts, in the second and following classifying operations, a relationship between the sheets and the classifying boxes assigned as sheet stacking destinations based on the classification information of the sheets read in the first classifying operation. The control section determines the classifying boxes where the sheets are to be stacked based on the classification information and an adjustment result, thereby controlling a classifying operation. A sheet classifying method is also disclosed.

Description: The present invention relates to a sheet classifying apparatus and method that perform so-called rearrangement of mailpieces, i.e., rearrange a plurality of sheets, and in particular, mailpieces, in order based on classification information by classifying and stacking the sheets in classifying boxes corresponding to the classification information added to the surfaces of the sheets or mailpieces. In the mail delivery system, first, the mailpieces are classified in units of destination areas based on the recognition results of postal codes written/printed on the surfaces of the mailpieces to correspond to the destination areas (the first classifying operation). After the mailpieces are classified, they are rearranged, in accordance with the addresses and the like written/printed on the mailpieces, in the delivery route order with which the mailpieces are delivered (the second classifying operation). In the conventional mail delivery system, as disclosed in, e.g., AUTOMATION AND RETAIL EQUIPMENT, March 1992, the stage of classifying the mailpieces in units of destination areas as the first classifying operation is performed automatically by using, e.g., a bar code sorter. After the mailpieces are classified in units of destination areas, they are rearranged manually in the delivery order. With this method of rearranging the mailpieces manually, rearrangement is hard to eliminate errors, and is cumbersome and time-consuming. From these reasons, it is requested that the operation of classifying the mailpieces and rearranging them in the delivery order (to be referred to as rearrangement hereinafter) be performed entirely automatically. A sheet classifying apparatus that performs this rearrangement is proposed in Japanese Patent Laid-Open No. 8-66661. In this proposed sheet classifying apparatus, first, paper sheets sent one by one from a supply section are classified and stacked in accordance with classification information in a plurality of classifying boxes having feed-out mechanisms. After the first classifying operation is ended, the sheets that are fed out in the stacked state from the respective classifying boxes continuously in a predetermined classifying box order are reset in the supply section. The sheets set in the supply section are fed out again one by one, and are classified and stacked in the classifying boxes in accordance with classification information. These operations are repeated until rearrangement is completed. If a classifying box in which classified sheets are to be stacked is full, the sheets are classified and stacked in an overflow classifying box. In the sheet classifying apparatus described above, the pieces of classification information are assigned to the respective classifying boxes such that the sheets are classified and stacked in the corresponding classifying boxes in accordance with the pieces of classification information, without considering the numbers of sheets to be stacked in the respective classifying boxes. Therefore, in the second classifying operation, if the count of sheets to be classified in the first classifying box is 0 and the number of sheets to be classified in the second classifying box is large, despite that the first classifying box is empty, overflow occurs in the second classifying box. EP-0718049 discloses an apparatus for sorting sheets, which can form a delivery route by repeating sorting operations and preventing overflow of sheets. Auxillary sorting compartments are provided in the accumulating means in the sorting operation for the first time, and when an overflow occurs, the allocated sorting compartments are shifted each by one compartment to the side of the auxiliary sorting compartment. Unfortunately, the coded indicia of the sheets do not indicate particular boxes or bins in which the sheets are to be stacked. Instead, the coded indicia only indicate the order of stacking. Therefore, the operator does not known before the start of the stacking operation the relationship between the coded indicia on the sheets and the destination box numbers. It is an object of the present invention to provide a sheet classifying apparatus and method in which overflow from a classifying box is prevented. The object of the present invention is achieved with the features of the claims. There is provided a sheet classifying apparatus comprising supply means for supplying a plurality of sheets set in units of classifying operations to a convey route one by one, detection means for reading classification information added to the sheets, a plurality of classifying boxes in which a predetermined number of sheets conveyed on the convey route are stacked, reset means for automatically resetting the sheets in the classifying boxes in the supply means in accordance with a predetermined classifying box order, thereby preparing for a second and following classifying operations, adjusting means for adjusting, in the second and following classifying operations, a relationship between the sheets and the classifying boxes assigned as sheet stacking destinations based on the classification information read by the detection means in the first classifying operation, wherein said adjusting occurs if the number of sheets to be stacked in a particular box exceeds the capacity of that particular box and the number of sheets to be stacked in a particular box is zero, and control means for determining the classifying boxes where the sheets are to be stacked based on the classification information read by the detection means and an adjustment result of the adjusting means, thereby controlling a classifying operation. Brief Description of the Drawings Fig. 1 is a schematic diagram showing the arrangement of a sheet classifying apparatus according to an embodiment of the present invention; Fig. 2 is a block diagram showing the arrangement of the sheet classifying apparatus shown in Fig. 1; Fig. 3 is a table showing the relationship between the machine codes of a stacking order table shown in Fig. 2 and order information; Fig. 4 is a table showing the relationship between the order information of the first table of a classifying box assignment table shown in Fig. 2 and the classifying box numbers; Fig. 5A is a table showing the relationship between the order information of the second table of the classifying box assignment table shown in Fig. 2 and the classifying box numbers, and Fig. 5B is a table showing the relationship between the updated order information of the second table shown in Fig. 5A and the classifying box numbers; and Fig. 6 is a table showing the relationship between the order information stored in a memory shown in Fig. 2 and the number of sheets. Description of the Preferred Embodiment The present invention will be described in detail with reference to the accompanying drawings. Fig. 1 shows the arrangement of a sheet classifying apparatus according to an embodiment of the present invention. Pieces of classification information are added to the surfaces of a plurality of sheets 1 which are to be rearranged, and these sheets 1 are collectively set in a supply section 2. The pieces of classification information are, e.g., the postal code or address written/printed on the surface of the mailpiece, or a code (e.g., a bar code) indicating such information. More specifically, the classification information designates the destination area of the mailpiece and the delivery order (to be referred to as order information hereinafter) of the mailpiece in this designation area. The sheets 1 set in the supply section 2 are fed one by one with a supply means, e.g., a suction belt, to a convey route 3 (indicated by an alternate long and short dashed line in Fig. 1). The sheets 1 supplied one by one from the supply section 2 are supplied to a detecting section 6 through a switch-back section 4 and an aligning section 5. The switch-back section 4 switches the convey direction of the sheets 1 in order to align the direction of the sheets 1 when being fed out from the supply section 2 with the direction of the sheets 1 when being stacked in the supply section 2. The aligning section 5 eliminates a skew in the convey direction of the sheets 1 in the supply section 2 and the switch-back section 4. The detecting section 6 reads the classification information added to the surface of a sheet 1 under conveyance, and the classification information is sent to a control section 7 as a machine code. During reading, a sheet 1 detected as unreadable or a sheet 1 which has not a classifying target is classified in a rejection classifying box 8. The control section 7 refers to a classifying box assignment table (to be described later) in accordance with order information corresponding to the read classification information, thereby determining in which one of classifying boxes 9 the sheet 1 in question is to be classified. More specifically, the control section 7 transmits a switching control signal to a course selector 10 provided to the determined classifying box 9. The course selector 10 is turned on/off by this control signal to branch the sheet 1 in question from the convey route 3 and to drop it in the corresponding classifying box 9. When all the sheets 1 set in the supply section 2 are classified and stacked in the classifying boxes 9 corresponding to the classification information attached to them, the first classifying operation is ended. In the second classifying operation, first, feed-out mechanisms 11 are driven to feed the sheets 1 stacked in the respective classifying boxes 9 in the first classifying operation to the convey route 3 in a predetermined classifying box order. The fed sheets 1 are reset in the supply section 2 and are fed one by one to the convey route 3 in the second classifying operation. The fed sheets 1 are subjected to an operation identical to the first classifying operation described above, so that they are classified in the corresponding classifying boxes 9 again. The second classifying operation is identical to the first classifying operation, and a detailed description thereof will thus be omitted. When all the sheets 1 reset in the supply section 2 are classified and stacked in the corresponding classifying boxes 9 in this manner, the second classifying operation is ended. When the operation described as the second classifying operation is repeated, classification can be performed an arbitrary number of times in accordance with the number of sheets to be rearranged, i.e., in accordance with the number of digit positions of the order information. If an assigned classifying box 9 is already full, the sheet 1 is stacked in an overflow box 12. The characteristic feature of the present invention resides in assignment of the classifying boxes 9 by the control section 7, and in particular in assignment of the classifying boxes 9 in the second and following classifying operations. Fig. 2 shows the arrangement of the sheet classifying apparatus shown in Fig. 1, in which reference numeral 7a denotes an assignment adjusting section; 201, a stacking order table; 202, a classifying box assignment table; and 203, a memory. The assignment adjusting section 7a is provided to the control section 7 to adjust assignment of the classifying boxes 9. A relationship between machine codes and order information as the stacking order is set in the stacking order table 201. A relationship between the order information and the classifying box numbers is set in the classifying box assignment table 202. The number of sheets in units of classifying boxes is stored in the memory 203 in accordance with the detection result. The classifying box assignment table 202 has a first table 202a which is referred to in the first classifying operation, a second table 202b which is referred to in the second classifying operation, and a third table 202c which is referred to in the third classifying operation. The number of sheets is the number of sheets 1 to be classified in a classifying box 9 defined by the order information. In other words, the number of sheets is the number of sheets 1 to be stacked in one classifying box 9. Referring to Fig. 2, the classification information added to the sheet 1 is read by the detecting section 6, and a machine code as this detection result is sent to the control section 7. The control section 7 refers to the stacking order table 201 to obtain order information corresponding to the sent machine code. In the stacking order table 201, pieces of order information 22 are set to correspond to machine codes 21, as shown in Fig. 3. Subsequently, the control section 7 refers to the classifying box assignment table 202 to obtain a classifying box number corresponding to the order information 22 obtained from the stacking order table 201. As shown in Fig. 4, in the classifying box assignment table 202, the relationship between the order information 22 and a classifying box number 23 of a classifying box to which the sheet having this order information 22 should be classified is set in each of the first to third tables 202a, 202b, and 202c in units of classifying operations. Based on the registered contents of the stacking order table 201 and classifying box assignment table 202, the control section 7 determines the classifying box 9 to which a sheet 1 whose classification information is read by the detecting section 6 should be classified, as described above, and controls the course selector 10 provided to this classifying box 9 in accordance with this determination result. The sheet 1 under conveyance on the convey route 3 is then classified and stacked in one of the classifying boxes 9 determined by the control section 7. At this time, the control section 7 stores, in the memory 203, the numbers of sheets to be stacked in the respective classifying boxes 9 in accordance with the digits of the respective digit positions of the order information. In other words, the numbers of sheets 1 to be stacked in the respective classifying boxes 9 in units of classifying operations are stored in the memory 203. In the second and following classifying operations, the assignment adjusting section 7a of the control section 7 refers to the memory 203 to adjust assignment of the classifying boxes 9 in units of classifying operations. An operation will be described wherein the pieces of order information corresponding to the pieces of classification information added to the sheets 1 are defined as "000" to "999" and that these sheets 1 are to be rearranged in the order indicated by the order information by using ten classifying boxes 9 added with numbers 0 to 9. In the first classifying operation, the first table 202a of the classifying box assignment table 202 is referred to to obtain the number 23 of a classifying box corresponding to the order information 22 obtained from the stacking order table 201. In the first table 202a, as shown in Fig. 4, numbers equal to the digits of the unit's places of the pieces of order information 22 are assigned to the corresponding classifying boxes as their numbers 23. The control section 7 classifies and stacks each sheet 1 in the classifying box 9 corresponding to the digit of the unit's place of its order information 22 in accordance with the number 23 of the classifying box obtained from the first table 202a. Simultaneously, every time order information is obtained from the stacking order table 201, the control section 7 stores the obtained order information in the memory 203. When all the sheets 1 set in the supply section 2 are classified and stacked in the corresponding classifying boxes 9 in accordance with the digits of the unit's places of their order information 22, the first classifying operation is ended. Subsequently, the feed-out mechanisms 11 provided to the respective classifying boxes 9 are operated to automatically reset all the sheets 1 in the supply section 2 in a predetermined classifying box order, and thereafter the second classifying operation is started. For example, in the supply section 2, the sheets 1 are reset in the order of "0", "1", "2",..., and "9" from above. In the second classifying operation, pieces of classifying box assignment information are initially registered in the second table 202b of the classifying box assignment table 202, as shown in Fig. 5A. More specifically, numbers equal to the digits of the ten's places of the pieces of order information 22 are assigned to the corresponding classifying boxes 9 as their numbers 23. When, however, the numbers of sheets corresponding to the respective pieces of order information in the second classifying operation stored in the memory 203 shown in Fig. 6 are referred to, overflow occurs in sheets with pieces of order information whose digits in the ten's places are "2". More specifically, the number of sheets with pieces of order information whose digits in the ten's places are "0" is "XX", which is equal to or less than the capacity of the corresponding classifying box 9, and the number of sheets with pieces of order information whose digits in the ten's places are "1" is "0". Meanwhile, the number of sheets with pieces of order information whose digits in the ten's places are "2" is "YY", which exceeds the capacity of the corresponding classifying box 9. It is thus apparent that overflow occurs in a classifying box 9 with the number "2". Therefore, the assignment adjusting section 7a of the control section 7 updates the second table 202b shown in Fig. 5A to a second table 202b' as shown in Fig. 5B. More specifically, the second table 202b is updated such that sheets 1 with pieces of order information whose digits in the ten's places are "1" are not assigned to the original classifying box 9 but are assigned to two classifying boxes 9 designed to store the sheets 1 with pieces of order information whose digits in the ten's places are "2". In this case, the classifying boxes 9 whose numbers 23 are "1" and "2" are assigned as common classifying boxes to store sheets 1 with pieces of order information whose digits in the ten's places are "2". In Fig. 6, in place of the number of sheets with pieces of order information whose digits in the ten's places are "1", if the number of sheets with pieces of order information whose digits in the ten's places are "0" is "0", the sheets 1 with pieces of order information whose digits in the ten's places are "0" are not assigned to the original classifying box 9 in Fig. 5B, but the sheets 1 with pieces of order information whose digits in the ten's places are "1" may be assigned to the classifying box 9 whose number 23 is "0". When the classifying operation is performed in the same manner as described above by using the updated second table 202b', the sheets 1 with pieces of order information whose digits in the ten's places are "2" are stacked in the second classifying box 9 when the first classifying box 9 is full, so that overflow is prevented. In the third classifying operation, the third table 202c of the classifying box assignment table 202 is initialized so that the classifying boxes 9 are assigned in accordance with the digits in the hundred's places of the stacking order of the respective sheets. In the third classifying operation as well, the assignment adjusting section 7a of the control section 7 refers to the memory 203 to update the third table 202c. More specifically, the number of classifying boxes to be assigned is adjusted in accordance with the number of sheets, obtained by the first classifying operation, to be stacked in each classifying box 9, thereby preventing overflow. When the third classifying operation is ended, the sheets 1 have been classified in the corresponding classifying boxes 9 in accordance with the order of pieces of order information "000" to "999". As has been described above, with the sheet classifying apparatus and method according to the present invention, based on information obtained in the first classifying operation, the number of classifying boxes to be assigned to each order information is adjusted in the second and following classifying operations. As a result, overflow can be prevented, and efficient rearrangement can be performed.

Claims: A sheet classifying apparatus characterized by comprising: supply means (2) for supplying a plurality of sheets set in units of classifying operations to a convey route (3) one by one; detection means (6) for reading classification information added to the sheets; a plurality of classifying boxes (9) in which a predetermined number of sheets conveyed on said convey route are stacked; reset means (3, 11) for automatically resetting the sheets in said classifying boxes (9) in said supply means (2) in accordance with a predetermined classifying box order, thereby preparing for a second and following classifying operations; adjusting means (7a) for adjusting, in the second and following classifying operations, a relationship between the sheets and said classifying boxes (9) assigned as sheet stacking destinations based on the classification information read by said detection means (6) in the first classifying operation, wherein said adjusting occurs if the number of sheets to be stacked in a particular box exceeds the capacity of that particular box and the number of sheets to be stacked in a particular box is zero; and control means (7) for determining said classifying boxes (9) where the sheets are to be stacked based on the classification information read by said detection means (6) and an adjustment result of said adjusting means (7a), thereby controlling a classifying operation. An apparatus according to claim 1, wherein said control means (7) groups the sheets into a plurality of groups in accordance with the classification information read by said detection means (6), and determines said classifying boxes (9) as said sheet stacking destinations to correspond to the groups, and said adjusting means (7a) complimentarily increments/decrements the number of said classifying boxes (9) corresponding to each of the groups in the second and following classifying operations based on the classification information read by said detection means (6) in the first classifying operation, thereby adjusting the relationship between the sheets and said classifying boxes (9), and informs said control means (7) of an adjustment result. An apparatus according to claim 2, wherein said adjusting means (7a) increments/decrements the numbers of said classifying boxes (9) assigned to first and second ones of the groups to which said classifying boxes (9) have been initially assigned in a one-to-one correspondence in accordance with the numbers of said classifying boxes (9), and shifts by one a classifying box code assigned to a group sandwiched by the first and second groups, thereby adjusting the relationship between the sheets and said classifying boxes (9). An apparatus according to any of claims 1 to 3, further comprising storage means (203) for storing the number of sheets that are to be stacked in each of said classifying boxes (9) in each of the second and following classifying operations, the number of sheets being obtained from a read result of said detection means (6) in the first classifying operation, and wherein said adjusting means (7a) refers to said storage means (203) in the second and following classifying operations, thereby adjusting the relationship between the sheets and said classifying boxes. An apparatus according to any of claims 1 to 4, further comprising a stacking number table (201) in which a relationship between classification information of the sheets and a stacking order of the sheets is set, and a classifying box assignment table (202) in which a relationship between the stacking order and classifying box codes is set in units of classifying operations, and wherein said control means (7) refers to said stacking number table (201) based on the classification information read by said detection means, thereby reading out a stacking number, and refers to said classifying box assignment table based on the readout stacking number to read out classifying box numbers, thereby determining said classifying boxes as said sheet stacking destinations. An apparatus according to claim 5, wherein said adjusting means (7a) updates the relationship between the stacking order of said classifying box assignment table and the classifying box codes in the second and following classifying operations based on the classification information read by said detection means, and said control means (7) refers to said updated classifying box assignment table to read out the classifying box codes, thereby determining said classifying boxes (9) as said sheet stacking destinations. A sheet classifying method characterized by comprising the steps of: (a) setting a plurality of sheets (1) added with classification information; (b) sending out the sheets that are set onto a convey route (3) one by one; (c) reading the classification information of the sheet sent out to said convey route; (d) classifying the sheets into a plurality of classifying boxes (9) in accordance with the read classification information; (e) automatically resetting the sheets stacked in said classifying boxes (9) in a predetermined classifying box order; (f) sending out the sheets that are reset onto said convey route one by one; (g) adjusting a relationship between the sheets and said classifying boxes as classifying destinations in a second and following classifying operations based on the classification information read in a first classifying operation wherein said adjusting occurs if the number of sheets to be stacked in a particular box exceeds the capacity of that particular box and the number of sheets to be stacked in a particular box is zero; and (h) classifying again the sheets in said classifying boxes assigned thereto in accordance with an adjustment result. A method according to claim 7, wherein the step of adjusting the relationship between the sheets and said classifying boxes (9) comprises the step of adjusting the numbers of said classifying boxes (9) assigned as sheet classifying destinations that are grouped. An apparatus according to any of claims 3-6, wherein the box code comprises a box number. A method according to claim 7, further comprising the step of stacking some of the sheets in an overflow box (12) if, during the step (d) of classifying, the number of sheets stacked in any one classifying box exceeds the capacity of that classifying box. A method according to claim 7 wherein the step (g) of adjusting includes the step of updating a classifying box assignment table which specifies the assignments of the classifying boxes for all the sheets. A method according to claim 11, further comprising the step of revoking an assignment of a classifying box if the number of sheets to be stacked in that destination as determined in step (d) is zero.

Inventors: ITOH MINORU, YOSHITANI KAZUHITO, ITOH, MINORU, YOSHITANI, KAZUHITO
Applicants: NIPPON ELECTRIC CO, NEC CORPORATION
Application year: 1997
Main classification: B07C3
IPC codes: B07C3