JPH0981664A - Postal code recognition method, postal code recognition device and sorting machine - Google Patents

Abstract

(57) [Abstract] [PROBLEMS] To provide a postal code recognition method, a postal code recognition device, and a sorting machine with high accuracy in postal code recognition. SOLUTION: An in-frame handwritten character, an in-frame printed character, and an in-address printed character evaluation value determination unit 15b, 15f, 15j refer to a zip code from a character detection unit 14 with data in a character dictionary unit, respectively. Decide the in-house handwritten character, the printed character in the frame, and the printed character evaluation value in the address. In-frame handwritten characters, in-frame printed characters and in-address printed character threshold value selection units 15c, 15g, 15k are in-frame handwritten characters, in-frame printed characters and addresses corresponding to the postal code from the character detection unit 14. Select the internal print character threshold. Handwritten characters in a frame, printed characters in a frame, and printed characters in an address Evaluation value determination unit 1
Each of 5d, 15h, and 15l determines whether or not the evaluation value is larger than a threshold value, and only when the evaluation value is larger, the regular zip code recognizing unit 15m recognizes the zip code from the character detecting unit 14 as a regular zip code. .

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a zip code recognizing method and a zip code recognizing device which optically recognizes a zip code written on a postal matter, and a zip code recognized by the zip code recognizing device. And a sorting machine that sorts mail according to.

[0002]

2. Description of the Related Art A conventional postal code recognizing method and postal code recognizing device are for recognizing image information obtained by optically reading a postal code written on a mail by referring to a character dictionary. .

[0003]

However, in the conventional zip code recognizing method and zip code recognizing device, the image information of the zip code is referred to the character dictionary according to a uniform standard even though there are different types of zip codes. Therefore, there is a problem that the accuracy of zip code recognition is low.

An object of the present invention is to provide a zip code recognizing method, a zip code recognizing device, and a sorting machine which have high accuracy in recognizing a zip code.

[0005]

In order to solve the above problems, the present invention should optically read a postal code written on a postal matter, and the read postal code should describe the postal code. Determine whether it is a handwritten number or print type in a frame that defines a certain area, or print within the address area that defines the area where the postal code should describe the address It is determined whether or not it is a print type, the character evaluation value is calculated with reference to the character dictionary based on these determination results, and the character threshold value is selected, and the character evaluation value is the character threshold value. It is characterized in that the read zip code is recognized as a regular zip code only when it is determined that the zip code is larger than the value.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 is an external view showing a sorting machine 1 according to the present invention. The sorting machine 1 has a large box-shaped sorting machine body 1a, reads an address and a zip code on the postal matter P, recognizes the address and the zip code from the read contents, and uses these addresses and the zip code. The mail P is classified. The sorting machine body 1a is provided with a supply unit 2, a scanner unit 3, a transport unit 4, a sorting unit 5, and a storage unit 6.

The supply unit 2 has a placing table 7 on which the postal matter P is placed, and an ejecting section 8 for taking out the postal matter P one by one from the placing table 7 and sending it to the scanner section 3 and the transport section 4. ing. The scanner unit 3 optically reads the entire image on the postal matter P supplied by the supply unit 2 one by one, and generates image information. The transport unit 4 transports the postal matter P passing through the scanner unit 3 to the sorting unit 5. The storage section 6 has a large number of storage pockets 6a for storing the postal matter P in sections. The sorting unit 6 sorts the postal matter P sent by the transport unit 4 into the storage pockets 6a based on the image information from the scanner unit 3.

FIG. 2 is a diagram showing a schematic configuration of the sorting machine 1 according to the present invention. As shown in FIG. 2, the sorting machine 1
Has a supply unit 2, a scanner unit 3, a conveyance unit 4, a sorting unit 5, and a recognition unit 10 and a control unit 11 connected to these. This control unit 11 is a sorting machine
Control the overall behavior of.

As shown in FIG. 3, the recognition section 10 includes an area detection section 12, a character line detection section 13, and a character detection section 14.
A postal code recognition unit 15, a character recognition unit 16, a block character recognition unit 17, an address recognition unit 18, and a character dictionary unit 19.
And the address dictionary unit 20.

The area detection unit 12 detects an area in which an address and a postal code are described from the image supplied from the scanner unit 3 by the shape and position of the area. The character line detection unit 13 detects a character line in which an address and a postal code in the area detected by the area detection unit 12 are described. The character detection unit 14 detects and cuts out the characters of the character line detected by the character line detection unit 13 one by one, that is, detects and cuts out the character information corresponding to the address (postal code).

The postal code recognizing unit 15 is a character detecting unit 1.
4, the detected and cut out characters (postal code) are collated with the character data stored in the character dictionary section 19 to recognize the postal code, and distinguish between handwritten and printed characters, address and The position and direction of the postal code are determined. The method and means for recognizing the postal code in the postal code recognizing unit 15 will be described in detail later.

The character recognition unit 16 recognizes a character by collating the character supplied from the character detection unit, that is, the detected and cut out character with the character data stored in the character dictionary unit 19.
Similarly, the block character recognizing unit 17 also recognizes a character by comparing the character supplied from the character detecting unit 14, that is, the detected and cut out character with the character data stored in the character dictionary unit 19.
The address recognition unit 18 recognizes the address by collating the characters supplied from the character detection unit 14, that is, the characters detected and cut out, with the address data stored in the address dictionary unit 20.

The character recognizing unit 16 and the city block character recognizing unit 17 are further arranged to discriminate between handwritten characters and printed characters, and to discriminate a writing direction of an address or a postal code.
As a method of distinguishing between handwritten characters and printed characters, for example, the method described in Japanese Patent Laid-Open No. 64-14682 is used. That is, the parameters that characterize the read characters are extracted,
By comparing this parameter with a reference value, it is possible to distinguish between handwritten characters and printed characters.

Next, a method and means for recognizing a zip code in the zip code recognizing section 15 will be described with reference to FIGS. 4 to 7.

As shown in FIG. 4, the postal code recognition unit 1
Reference numeral 5 denotes an in-frame handwritten character determination unit 15a, an in-frame handwritten character evaluation value determination unit 15b, an in-frame handwritten threshold value selection unit 15c, an in-frame handwritten character evaluation value determination unit 15d, In-frame print character determination unit 15
e, an in-frame printed character evaluation value determination unit 15f, an in-frame printed character threshold value selection unit 15g, and an in-frame printed character evaluation value determination unit 15h.
An in-address print character determining unit 15i, an in-address print character evaluation value determining unit 15j, and an in-address print character threshold selecting unit 15k.
And an in-address print character evaluation value determination unit 15l and a regular postal code recognition unit 15m.

The in-frame handwritten character determination unit 15a, the in-frame printed character determination unit 15e, and the in-address printed character determination unit 15i are connected to the character detection unit 14. The in-frame handwritten character evaluation value determination unit 15b, the in-frame printed character evaluation value determination unit 15f, and the in-address printed character evaluation value determination unit 15j are the character dictionary unit 1
9 is connected. The regular postal code recognition unit 15m
Are connected to the control unit 11.

Whether the handwritten character determination unit 15a in the frame is a handwritten number in the frame defining the area in which the postal code from the character detection unit 14 should describe the postal code. Determine no. Handwritten character evaluation value determination unit 15b in the frame
When the postal code from the character detection unit 14 is determined by the in-frame handwritten character determination unit 15a to be a handwritten number in the frame, the postal code from the character detection unit 14 is converted into a character. The in-frame handwriting evaluation value is determined with reference to the data in the dictionary section 19.

The in-frame handwriting threshold selection unit 15c is
If the postal code from the character detection unit 14 is determined by the in-frame handwriting determination unit 15a to be a handwritten number in the frame, the postal code corresponding to the postal code from the character detection unit 14 Select the handwriting threshold.

The in-frame handwriting evaluation value determination unit 15d determines whether the in-frame handwriting evaluation value is larger than the in-frame handwriting threshold value. The regular postal code recognition unit 15m determines the character detection unit only when the in-frame handwriting evaluation value determination unit 15d determines that the in-frame handwriting evaluation value is greater than the in-frame handwriting threshold value. Recognize the postal code from 14 as a legitimate postal code.

The in-frame print character determination 15e determines whether or not the zip code from the character detection unit 14 is a print character in a frame defining an area in which the zip code should be written. . The in-frame printed character evaluation value determination unit 15f determines the character detection unit when the in-frame printed character determination unit 15e determines that the postal code from the character detection unit 14 is a print type character in the frame. The postal code from 14 is referred to the data of the character dictionary section 19 to determine the print character evaluation value in the frame.

The in-frame print character threshold value selection unit 15g is
If the postal code from the character detection unit 14 is determined by the in-frame print character determination unit 15e to be a printed number in the frame, the postal code in the frame corresponding to the postal code from the character detection unit 14 Select the print character threshold.

The in-frame print character evaluation value determination unit 15h determines whether the in-frame print character evaluation value is larger than the in-frame print character threshold value. The regular zip code recognizing unit 15m outputs the character from the character detecting unit 14 only when the in-frame print character evaluation value determining unit 15h determines that the in-frame print character evaluation value is larger than the in-frame print character threshold value. Recognize postal codes as legitimate postal codes.

The in-address printing character determining unit 15i determines whether the postal code from the character detecting unit 14 is a print character in an address area defining an area in which an address should be written. To do. Printed character evaluation value determination unit 15 in the address
j is the postal code from the character detection unit 14 when the postal code from the character detection unit 14 is determined by the in-address print character determination unit 15i to be a print type character in the address area. The print character evaluation value in the address is determined with reference to the data in the dictionary section 19.

The printing character threshold selection unit 15k in the address
Corresponds to the postal code from the character detection unit 14 when the postal code from the character detection unit 14 is determined by the in-address printing character determination unit 15k to be a printed number in the address area. Select the print character threshold within the specified address.

The in-address printable character evaluation value determination unit 151 is
It is determined whether or not the print character evaluation value in the address is larger than the print character threshold value in the address. The regular postal code recognition unit 15m
Only when the in-address printing character evaluation value determining unit 151 determines that the in-address printing character evaluation value is larger than the in-address printing character threshold value, the postal code from the character detecting unit 14 is changed to a regular postal code. Recognize that.

In the zip code recognizing unit shown in FIG. 4, only the means related to any one of the in-frame handwritten character determination unit 15a, the in-frame printed character determination unit 15e, and the in-address printed character determination unit 15i is used. Alternatively, the handwritten character determination unit 15a in the frame, the printed character determination unit 15e in the frame, and the printed character determination unit 15i in the address may be configured by only two units.

The in-frame handwriting threshold selection unit 15c is
As shown in FIG. 5, the in-frame handwriting threshold input unit 2 for inputting the threshold value corresponding to the in-frame handwriting (0 to 9) in advance.
1, a data format conversion section 22 for converting the data of the handwriting threshold value input section 21 in the frame into a predetermined code (for example, ASCII code), and data from the data format conversion section 22 are stored. It has a data storage unit 23 and a threshold value selection unit 24 connected to the data storage unit 23, the character detection unit 14 and the in-frame handwritten character evaluation value determination unit 15d. The threshold selection unit 24 refers to the postal code from the character detection unit 14 with the data in the data storage unit 23 to select the in-frame handwriting threshold value. For example, when the postal code is “210”, the threshold selection unit 24
Selects the in-frame handwriting threshold value as "466".

The in-frame handwriting threshold selection unit 15g is
As shown in FIG. 6, the in-frame print character threshold value input unit 2 for inputting a threshold value corresponding to the in-frame print character (0 to 9) in advance.
5, a data format conversion unit 26 for converting the data of the print character threshold value input unit 25 into a predetermined code (for example, ASCII code), and data for storing the data from the data format conversion unit 26. The storage unit 27 has a threshold value selection unit 28 connected to the data storage unit 27, the character detection unit 14, and the in-frame print character evaluation value determination unit 15h. The threshold selection unit 28 refers to the postal code from the character detection unit 14 with the data in the data storage unit 27 to select the in-frame print character threshold value. For example, when the postal code is “210”, the threshold selection unit 28
Selects the in-frame print character threshold value as "333".

The in-frame handwriting threshold selection unit 15k is
As shown in FIG. 7, an in-address printing character threshold input unit 29 for pre-inputting a threshold value corresponding to the in-address printing character (0 to 9) and this in-address printing character threshold input unit 29. Format conversion section 30 for converting the data of the above into a predetermined code (for example, ASCII code), a data storage section 31 for storing the data from this data format conversion section 30, this data storage section 31, and the character detection. It has a threshold value selection unit 32 connected to the unit 14 and the in-address printing character evaluation value determination unit 151. The threshold selection unit 32 refers to the postal code from the character detection unit 14 with the data in the data storage unit 31 to select the in-frame print character threshold value. For example, when the postal code is “210”, the threshold selection unit 32 selects the in-frame print character threshold as “344”.

[0031]

According to the present invention, a zip code recognizing method, a zip code recognizing device, and a sorting machine having high zip code recognition accuracy can be obtained.

[Brief description of drawings]

FIG. 1 is an external view showing an external appearance of a sorting machine for explaining an embodiment of the present invention.

FIG. 2 is a diagram showing an outline of the sorting machine of FIG.

3 is a block diagram showing a recognition unit of the sorting machine of FIG. 2. FIG.

FIG. 4 is a block diagram showing a postal code recognition unit in the recognition unit of FIG.

5 is a block diagram showing an in-frame handwriting threshold value selecting unit in the postal code recognizing unit in FIG. 4;

6 is a block diagram showing an in-frame print character threshold value selection unit in the postal code recognition unit of FIG. 4;

FIG. 7 is a block diagram showing a print character threshold value selecting unit in the address in the postal code recognizing unit of FIG. 4;

[Explanation of symbols]

 1 Sorting machine 2 Supply section 3 Scanner section 4 Conveying section 5 Sorting section 10 Recognition section 11 Control section 14 Character detection section 15 Postal code recognition section 15a In-frame handwriting determination section 15b In-frame handwriting evaluation value determination section 15c In-frame handwriting Threshold selection unit 15d In-frame handwriting evaluation value determination unit 15e In-frame printed character evaluation unit 15f In-frame printed character evaluation value determination unit 15g In-frame printed character threshold value selection unit 15h In-frame printed character evaluation value determination unit 15i Address Inner print character determination unit 15j Address in-print character evaluation value determination unit 15k In-address print character threshold selection unit 15l Address in-print character evaluation value determination unit 15m Regular postal code recognition unit 19 Character dictionary unit

Claims (12)

[Claims] 1. A zip code reading step of optically reading a zip code written on a postal matter to generate image information, and the zip code read in this zip code reading step should describe a zip code. And an in-frame handwriting determination step for determining whether or not it is a handwritten number in a frame that defines an area, and the postal code read in the postal code reading step is the in-frame handwriting. In-frame handwriting for determining the in-frame handwriting evaluation value by referring to the postal code read when it is determined to be a handwritten number in the frame in the character determination step with the data in the character dictionary section A character evaluation value determining step; and the zip code read in the zip code reading step, when the zip code is determined to be a handwritten number in the frame in the in-frame handwriting determination step. An in-frame handwriting threshold value selecting step for selecting an in-frame handwriting threshold value corresponding to a postal code, and whether the in-frame handwriting character evaluation value is larger than the in-frame handwriting threshold value In-frame handwriting evaluation value determination step for determining, and only when the in-frame handwriting evaluation value is determined to be greater than the in-frame handwriting threshold value in this in-frame handwriting evaluation value determination step A postal code recognizing method, comprising: a postal code recognizing step of recognizing the postal code read in the postal code reading step as an authentic postal code. 2. A zip code reading step of optically reading a zip code written on a postal matter to generate image information, and the zip code read in this zip code reading step should describe a zip code. In the frame print character determination step of determining whether or not the print character is within the frame defining the area, the postal code read in the postal code reading step is performed in the frame print character determination step. An in-frame print character evaluation value determining step of determining an in-frame print character evaluation value by referring to the postal code read when the print type is in the frame and the data of the character dictionary section; The postal code read in the postal code reading step, when the postal code read in the frame is determined to be a printed number in the frame In-frame print threshold selection step of selecting an in-frame print character threshold value corresponding to the flight number, and in-frame determining whether the in-frame print character evaluation value is greater than the in-frame print character threshold value. Read in the postal code reading step only when the print character evaluation value determination step and the print character evaluation value determination step in the frame determine that the print character evaluation value in the frame is larger than the print character threshold value in the frame. A method for recognizing a zip code, comprising the step of recognizing the zip code as a regular zip code. 3. A zip code reading step of optically reading a zip code written on a postal matter to generate image information, and the zip code read in this zip code reading step should describe an address. In the in-address print character determination step of determining whether or not the print character is in the address area that defines a certain area, the postal code read in the postal code reading step is in the in-address print character determination step. An in-address print character evaluation value determining step of determining an in-address print character evaluation value by referring to the zip code read in the data dictionary of the character dictionary unit when it is determined that the print character is in the address area, It is determined that the postal code read in the postal code reading step is a printed number in the address area in the address print character determination step. In the case of selecting the print character threshold value in the address corresponding to the read zip code, the print character threshold value in the address selection step, and the print character evaluation value in the address is greater than the print character threshold value in the address. Whether or not it is determined whether the print character evaluation value in the address is larger than the print character threshold value in the address in the address print value evaluation value determination step A postal code recognizing method comprising a regular postal code recognizing step for recognizing the postal code read in the postal code reading step as a regular postal code. 4. A zip code reading means for optically reading a zip code written on a postal matter to generate image information, and the zip code read by the zip code reading means should describe a zip code. And an in-frame handwriting determination unit that determines whether the number is a handwritten number in a frame that defines the area, and the postal code read by the postal code reading unit is the in-frame handwriting. In-frame handwriting for determining the handwritten character evaluation value in the frame by referring to the postal code read in the case where it is determined by the character determination means that the postal code is a number in the frame Character evaluation value determining means, and the postal code read when the postal code read by the postal code reading means is determined by the in-frame handwriting determination means to be a handwritten number in the frame In-frame handwriting corresponding to An in-frame handwriting threshold selection unit for selecting a desired value, and an in-frame handwriting evaluation value determination for determining whether the in-frame handwriting evaluation value is greater than the in-frame handwriting threshold And the mail read by the postal code reading means only when the in-frame handwriting evaluation value determining means determines that the in-frame handwriting evaluation value is larger than the in-frame handwriting threshold value. A postal code recognizing device having a regular postal code recognizing means for recognizing the number as a regular postal code. 5. A zip code reading means for optically reading a zip code written on a postal matter to generate image information, and the zip code read by the zip code reading means should describe a zip code. In the frame print character determining means for determining whether or not the print character is within the frame defining the area, and the postal code read by the postal code reading means in the frame print character determining means. In-frame print character evaluation value determining means for determining an in-frame print character evaluation value by referring to the postal code read when the print character is in the frame and the data of the character dictionary section, When the postal code read by the postal code reading means determines that the postal code within the frame is a printed number within the frame, the in-frame print character threshold corresponding to the read postal code is read. An in-frame print character threshold value selecting means for selecting a value; an in-frame print character evaluation value determining means for determining whether or not the in-frame print character evaluation value is greater than the in-frame print character threshold value; The zip code read by the zip code reading means is a regular zip code only when the inner print character evaluation value determination means determines that the print character evaluation value in the frame is larger than the print character threshold value in the frame. A zip code recognizing device having a regular zip code recognizing means for recognizing the zip code. 6. The zip code recognizing device according to claim 5, wherein the zip code read by the zip code reading means is within a frame defining a region in which the zip code should be written. In-frame handwriting determination means for determining whether or not it is the number of a handwriting, and the postcode read by the postal code reading means is a handwritten number in the frame by the in-frame handwriting determination means In the postcode reading means, an in-frame handwritten character evaluation value determining means for determining an in-frame handwritten character evaluation value by referring to the postal code read in the case where it is determined that If the read postal code is determined to be a handwritten number in the frame by the in-frame handwriting determination means, the in-frame handwriting threshold value corresponding to the read postal code is selected. Handwriting threshold value selection hand An in-frame handwriting evaluation value determining means for determining whether or not the in-frame handwriting evaluation value is larger than an in-frame handwriting threshold value; Regular postal code recognition that recognizes the postal code read by the postal code reading means as a regular postal code only when it is determined that the in-frame handwriting evaluation value is larger than the in-frame handwriting threshold value. A zip code recognizing device having means. 7. A postal code reading means for optically reading a postal code written on a postal matter to generate image information, and the postal code read by the postal code reading means should describe an address. An in-address print character determining means for determining whether or not a print character is in the address area defining a certain area, and the postal code read by the postal code reading means in the in-address print character determining means. In-address print character evaluation value determining means for determining the in-address print character evaluation value by referring to the data in the character dictionary section for the postal code read when it is determined that the print character is in the address area. And the zip code read when the zip code read by the zip code reading means is determined to be a printed number in the address area by the in-address print character determining means. In-address printing character threshold selection means for selecting a corresponding in-address printing character threshold value, and in-address printing character determining whether or not the evaluation value in the address printing character is greater than the in-address printing character threshold value The mail read by the postal code reading means only when the evaluation value determining means and the in-address printing character evaluation value determining means determine that the in-address printing character evaluation value is larger than the in-address printing character threshold value. A postal code recognizing device having a regular postal code recognizing means for recognizing the number as a regular postal code. 8. The postal code recognizing device according to claim 7, further, wherein the postal code read by the postal code reading means is within a frame defining an area in which a postal code should be written. An in-frame handwriting determination unit that determines whether or not the number is a handwritten number, and the postal code read by the postal code reading unit is in the frame by the in-frame handwriting determination unit. An in-frame handwritten character evaluation value determining means for determining an in-frame handwritten character evaluation value by referring to the data of the character dictionary section for the postal code read when it is determined to be a number, and the postal code reading means When the postal code read in is determined by the in-frame handwriting determination means to be a handwritten number in the frame, an in-frame handwriting threshold value corresponding to the postal code read in Selection of handwriting threshold value within the selected frame Means for determining whether or not the in-frame handwritten character evaluation value is greater than an in-frame handwritten character threshold value; and an in-frame handwritten character evaluation value determination means A regular zip code that recognizes the zip code read by the zip code reading means as a regular zip code only when it is determined that the in-frame handwriting evaluation value is larger than the in-frame handwriting threshold value. A zip code recognizing device comprising: a recognizing means. 9. The postal code recognizing device according to claim 8, wherein the postal code read by the postal code reading means is within a frame defining an area in which a postal code should be written. In-frame print character determining means for determining whether or not it is a print type character, and the postal code read by the postal code reading means is determined by the in-frame print character determining means to be a print type character in the frame. In this case, the postal code read in the postal code is read by the postal code reading value determining means for determining the printable character evaluation value in the frame with reference to the postal code read in the character dictionary data. In-frame print threshold value selecting means for selecting an in-frame print character threshold value corresponding to the read zip code when the in-frame print character determining means determines that it is a printed number in the frame An in-frame print character evaluation value determining means for determining whether the in-frame print character evaluation value is greater than an in-frame print character threshold value, and the in-frame print character evaluation value determining means And a regular zip code recognizing unit that recognizes the zip code read by the zip code reading unit as a regular zip code only when it is determined that the evaluation value is larger than the print character threshold value in the frame. Characteristic postal code recognition device. 10. A postal code recognizing means for optically reading and recognizing a postal code written on a postal matter, and a sorting means for classifying the postal matter according to the postal code recognized by the postal code recognizing means. In the sorting machine having the postal code recognizing means, the postal code recognizing means optically reads a zip code described in a mail piece to generate image information, and the zip code read by the zip code reading means. An in-frame handwritten character determination means for determining whether or not the number is a handwritten number in a frame that defines an area in which a zip code should be written; When the postal code is judged by the in-frame handwritten character determination means to be a handwritten number in the frame, the read postal code is referred to the data in the character dictionary section to evaluate the in-frame handwritten character. Determine the value In-frame handwriting evaluation value determining means, and read when the zip code read by the zip code reading means is determined by the in-frame handwriting determining means to be a handwritten number in the frame An in-frame handwriting threshold value selecting means for selecting an in-frame handwriting threshold value corresponding to the specified postal code, and the in-frame handwriting evaluation value is larger than the in-frame handwriting threshold value. The in-frame handwriting evaluation value determining means for determining whether or not the in-frame handwriting evaluation value determining means determines that the in-frame handwriting evaluation value is larger than the in-frame handwriting threshold value. Only in this case, there is provided a regular postal code recognition means for recognizing the postal code read by the postal code reading means as a regular postal code. 11. A zip code recognizing means for optically reading and recognizing a zip code written on a postal matter, and a sorting means for classifying the postal matter according to the zip code recognized by the zip code recognizing means. In the sorting machine having the postal code recognizing means, the postal code recognizing means optically reads a zip code described in a mail piece to generate image information, and the zip code read by the zip code reading means. The in-frame print character determining means for determining whether or not the number is a print character in a frame defining the area where the postal code should be written, and the postal code read by the postal code reading means. The in-frame print character evaluation value is determined by referring to the postal code read when the in-frame print character determining means determines that the print character is within the frame and the data in the character dictionary section. In-frame print character evaluation value determining means, and the read in the case where the postal code read by the postal code reading means is determined by the in-frame print character determining means to be a printed number in the frame In-frame print threshold selection means for selecting an in-frame print character threshold value corresponding to a postal code, and in-frame determining whether the in-frame print character evaluation value is greater than the in-frame print character threshold value. The print character evaluation value determining unit and the print character evaluation value determining unit in the frame read the postal code reading unit only when it is determined that the print character evaluation value in the frame is greater than the print character threshold value in the frame. A sorting machine having a regular zip code recognizing means for recognizing the zip code as a regular zip code. 12. A zip code recognizing means for optically reading and recognizing a zip code written on the mail, and a sorting means for classifying the mail according to the zip code recognized by the zip code recognizing means. In the sorting machine having the postal code recognizing means, the postal code recognizing means optically reads a zip code described in a mail piece to generate image information, and the zip code read by the zip code reading means. The print number determination means in the addressee for determining whether the number is a print character in the address area that defines the area in which the address should be written, and the postal code read by the postal code reading means The printing character evaluation in the address is performed by referring to the postal code read when the printing character determining unit in the address determines that the printing character is in the address area with the data in the character dictionary section. In-address print character evaluation value determining means for determining a value, and the postal code read by the postal code reading means is determined by the in-address print character determining means to be a printed number in the address area. In-address printing character threshold value selecting means for selecting an in-address printing character threshold value corresponding to the read zip code, and whether the in-address printing character evaluation value is larger than the in-address printing character threshold value. The in-address printing character evaluation value determining means for determining whether or not the mail is performed only when the in-address printing character evaluation value determining means determines that the in-address printing character evaluation value is larger than the in-address printing character threshold value. A sorting machine having a regular zip code recognizing means for recognizing the zip code read by the number reading means as a regular zip code.