Sorting apparatus

1. A sorting apparatus which sorts packages that are carried on a main conveyor, said sorting apparatus comprising:

a characteristic information obtaining unit configured to obtain characteristic information of each of the packages;

a branching unit configured to perform a branching operation for forwarding a predetermined package among the packages to a branch conveyor branching from the main conveyor;

an interval adjusting unit configured to adjust an interval between two of the packages, the two packages being a preceding package and a succeeding package which are sequentially forwarded to the main conveyor;

a branch control unit configured to cause said branching unit to change a speed of the branching operation for forwarding the preceding package to the branch conveyor according to the characteristic information of the preceding package obtained by said characteristic information obtaining unit, and to cause said branching unit to change a speed of the branching operation for forwarding the succeeding package to the branch conveyor according to the characteristic information of the succeeding package obtained by said characteristic information obtaining unit; and

an interval control unit configured to obtain a time required for the branching operation for the proceeding package, and cause said interval adjusting unit to increase the interval between the two packages in proportion to the obtained time required for the branching operation for the preceding package.

2. The sorting apparatus according to claim 1 , wherein the characteristic information indicates a fall possibility of a corresponding one of the packages which is associated with the characteristic information,

wherein the branch control unit is configured to cause said branching unit to perform the branching operation at a first speed if the fall possibility is equal to or less than a predetermined threshold, and

wherein the branch control unit is configured to cause said branching unit to reduce a speed of the branching operation below the first speed if the fall possibility is higher than the predetermined threshold.

3. The sorting apparatus according to claim 1 , wherein the characteristic information indicates a fall possibility of a corresponding one of the predetermined packages, and

wherein said branch control unit is configured to cause said branching unit to reduce a speed of the branching operation for the corresponding one of the predetermined packages in proportion to a degree of the fall possibility of the corresponding one of the predetermined packages.

4. The sorting apparatus according to claim 1 , wherein said interval adjusting unit is a sub conveyor which is disposed upstream with respect to the branch conveyor and can change a carriage speed independently of the main conveyor, and

wherein said interval control unit is configured to increase the interval between the two packages by reducing the carriage speed of the sub conveyor.

5. The sorting apparatus according to claim 1 , wherein the characteristic information indicates a fall possibility of a corresponding one of the packages which is associated with the characteristic information,

wherein the branch control unit is configured to cause said branching unit to perform the branching operation at a first speed if the fall possibility is equal to or less than a predetermined threshold, and

wherein the branch control unit is configured to cause said branching unit to reduce a speed of the branching operation to a second speed if the fall possibility is higher than the predetermined threshold, the second speed being half of the first speed.

6. A sorting apparatus which sorts packages that are carried on a main conveyor, said sorting apparatus comprising:

a characteristic information obtaining unit configured to obtain characteristic information of each of the packages;

a plurality of branching units configured to perform a branching operation for forwarding the packages to a plurality of branch conveyors branching from the main conveyor;

an interval adjusting unit configured to adjust an interval between two of the packages, the two packages being a preceding package and a succeeding package which are sequentially forwarded to the main conveyor;

a branch control unit configured to cause one of the branching units to change a speed of the branching operation for forwarding the preceding package to a corresponding one of the branch conveyors according to the characteristic information of the preceding package obtained by said characteristic information obtaining unit, and to cause another of the branching units to change a speed of the branching operation for forwarding the succeeding package to a corresponding one of the branch conveyors according to the characteristic information of the succeeding package obtained by said characteristic information obtaining unit; and

an interval control unit configured to obtain a time required for the branching operation for the proceeding package, and cause said interval adjusting unit to increase the interval between the two packages in proportion to the obtained time required for the branching operation for the preceding package.

7. The sorting apparatus according to claim 6 , wherein the characteristic information indicates a fall possibility of a corresponding one of the packages which is associated with the characteristic information,

wherein the branch control unit is configured to cause said branching units to perform the branching operations at a first speed if the fall possibility is equal to or less than a predetermined threshold, and

wherein the branch control unit is configured to cause said branching units to reduce a speed of the branching operations below the first speed if the fall possibility is higher than the predetermined threshold.

8. The sorting apparatus according to claim 6 , wherein the characteristic information indicates a fall possibility of a corresponding one of the packages, and

wherein said branch control unit is configured to cause said branching units to reduce a speed of the branching operations for the corresponding one of the packages in proportion to a degree of the fall possibility of the corresponding one of the packages.

9. The sorting apparatus according to claim 6 , wherein said interval adjusting unit is a sub conveyor which is disposed upstream with respect to the branch conveyors and can change a carriage speed independently of the main conveyor, and

wherein said interval control unit is configured to increase the interval between the two packages by reducing the carriage speed of the sub conveyor.

10. The sorting apparatus according to claim 6 , wherein the characteristic information indicates a fall possibility of a corresponding one of the packages which is associated with the characteristic information,

wherein the branch control unit is configured to cause said branching units to perform the branching operations at a first speed if the fall possibility is equal to or less than a predetermined threshold, and

wherein the branch control unit is configured to cause said branching units to reduce a speed of the branching operations to a second speed if the fall possibility is higher than the predetermined threshold, the second speed being half of the first speed.

11. The sorting apparatus according to claim 6 , wherein the interval control unit causes the interval adjusting unit to increase the interval between the two packages if a branching position of the succeeding package is not upstream of a branching position of the preceding package, and

wherein the interval control unit causes the interval adjusting unit not to increase the interval between the two packages if the branching position of the succeeding package is upstream of the branching position of the preceding package.

12. A sorting apparatus which sorts packages that are carried on a main conveyor, said sorting apparatus comprising:

a characteristic information obtaining unit configured to obtain characteristic information of each of the packages;

a plurality of branching units configured to perform a branching operation for forwarding the packages to a plurality of branch conveyors branching from the main conveyor;

an interval adjusting unit configured to adjust an interval between two of the packages, the two packages being a preceding package and a succeeding package which are sequentially forwarded to the main conveyor;

branch control means for causing one of the branching units to change a speed of the branching operation for forwarding the preceding package to a corresponding one of the branch conveyors according to the characteristic information of the preceding package obtained by said characteristic information obtaining unit, and causing another of the branching units to change a speed of the branching operation for forwarding the succeeding package to a corresponding one of the branch conveyors according to the characteristic information of the succeeding package obtained by said characteristic information obtaining unit; and

interval control means for obtaining a time required for the branching operation for the proceeding package, and causing said interval adjusting unit to increase the interval between the two packages in proportion to the obtained time required for the branching operation for the preceding package.

13. The sorting apparatus according to claim 12 , wherein the characteristic information indicates a fall possibility of a corresponding one of the packages which is associated with the characteristic information,

wherein the branch control means causes said branching units to perform the branching operations at a first speed if the fall possibility is equal to or less than a predetermined threshold, and

wherein the branch control means causes said branching units to reduce a speed of the branching operations below the first speed if the fall possibility is higher than the predetermined threshold.

14. The sorting apparatus according to claim 12 , wherein the characteristic information indicates a fall possibility of a corresponding one of the packages, and

wherein said branch control means causes said branching units to reduce a speed of the branching operations for the corresponding one of the packages in proportion to a degree of the fall possibility of the corresponding one of the packages.

15. The sorting apparatus according to claim 12 , wherein said interval adjusting unit is a sub conveyor which is disposed upstream with respect to the branch conveyors and can change a carriage speed independently of the main conveyor, and

wherein said interval control means increases the interval between the two packages by reducing the carriage speed of the sub conveyor.

16. The sorting apparatus according to claim 12 , wherein the characteristic information indicates a fall possibility of a corresponding one of the packages which is associated with the characteristic information,

wherein the branch control means causes said branching units to perform the branching operations at a first speed if the fall possibility is equal to or less than a predetermined threshold, and

wherein the branch control means causes said branching units to reduce a speed of the branching operations to a second speed if the fall possibility is higher than the predetermined threshold, the second speed being half of the first speed.

17. The sorting apparatus according to claim 12 , wherein the interval control means causes the interval adjusting unit to increase the interval between the two packages if a branching position of the succeeding package is not upstream of a branching position of the preceding package, and

wherein the interval control means causes the interval adjusting unit not to increase the interval between the two packages if the branching position of the succeeding package is upstream of the branching position of the preceding package.