JPS6239458B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a character line direction determining circuit for an optical character reading device that reads a postal code from a conveyed mail piece, for example in an automatic postal code reading and sorting machine.

Generally, in the case of an optical character reading device that reads a postal code from a transported mail item, the mail items to be read include handwritten mail items and printed mail items. For handwritten mail, a prescribed frame for recording the postal code is printed on a predetermined part of the mail, so that the direction in which the postal code is recorded is fixed. However, for printed mail, the direction in which the postal code is recorded is not constant; for example, in Figure 1 a.
There are two types of postal items, such as the one where the postal code N is recorded vertically and horizontally, and the other where the postal code N is recorded horizontally and horizontally, as shown in Figure 1b, and if these two types of postal items coexist, it becomes unreadable. I become confused. For this reason, conventionally, an operator visually determines whether the postal code on a mail piece is written vertically and horizontally or horizontally, and based on this, the operator selects a mode designation switch for the character recording direction to perform reading. That's what I do. However, such reading based on visual judgment by an operator is very troublesome and has the problem of lacking reliability.

This invention was made in view of the above-mentioned circumstances, and its purpose is to be able to automatically determine the direction of character lines on an inherited object, thereby increasing the processing speed for character reading. The present invention also provides a character line direction determination circuit that can improve the reading rate.

An embodiment of the present invention will be described below with reference to the drawings.

First, an optical character reading device using the character line direction determining circuit of the present invention will be explained with reference to FIG. 1 is an object to be read to be conveyed, for example, mail P
A first reading section provided along the conveyance direction a,
Imager such as line array 2, imaging lens 3,
It consists of an irradiation lamp 4, a reflecting mirror 5, and condensing lenses 6 and 7, and is adapted to optically read and scan the above-mentioned mail P. In this case, the line array 2 is of a self-scanning type formed by arranging a plurality of solid-state image sensors, and is arranged in a direction perpendicular to the transport direction a of the mail P. Therefore, when the mail P is conveyed in the direction of the arrow a and corresponds to the first reading section 1, the light emitted from the irradiation lamp 4 passes through the reflector 5 and the condensing lenses 6 and 7 to the mail P. The reflected light is guided to the line array 2 via the imaging lens 3. In this way, the mail P by the line array 2
The upper part is line-scanned in a direction perpendicular to the conveyance direction a, and the line scan appears to sequentially move in the opposite direction to the conveyance direction a as the mail P moves.

Line array 2 outputs a black block signal (logic "1" signal) corresponding to the character (black block) and a white block signal (logic "0" signal) corresponding to the blank area (white block). It's becoming like that. Further, reference numeral 11 denotes a second reading section provided along the transport direction a of the mail P along with the first reading section 1, and includes an imager such as a line array 12, an imaging lens 13, an irradiation lamp 14, and a reflecting mirror 15. , condensing lenses 16 and 17, and is adapted to optically read and scan the mail P. In this case, line array 12 is similar to line array 2 described above. Reference numeral 20 denotes a character line direction determining circuit according to the present invention, which determines the character line direction on the mail P based on the output of the first reading section 1, that is, the output of the line array 2.
Furthermore, 30 is a character recognition section, and the second reading section 1
1, that is, the output of the line array 12, is supplied as a read signal, and the read character (zip code) based on the read signal is recognized according to the determination result of the character line direction determination circuit 20. It is.

Here, FIG. 3 shows an example of an object to be read, that is, a postal object P used in the above-mentioned optical character reading device, and a postage mark E is printed on the upper right corner of the illustration of the postal object P. Along with this, the postal code N, destination C, etc. are type-printed in horizontal position and horizontal writing. In this case, generally when the postal code N and address C are type-printed on the postal item P, the printing direction is made to correspond to the shape of the separate fee mark E as shown in the figure. In this way, the mail P is conveyed in the direction of arrow a in an upright position.

FIG. 4 shows a character line direction determining circuit 20 of the present invention.
This shows the details. That is, the character line direction determination circuit 20 includes a postage mark detection unit 20 ₁ that detects the postage payment mark E on the postal item P based on the output of the first reading unit 1; a shape determination unit 20 ₂ that determines the shape of the separate payment mark E in a certain direction;
It also includes a gate circuit, for example, an AND circuit ₂₀₃ , which determines the direction of character lines on the mail P based on the output of the fee-based payment mark detection section ₂₀₁ and the output of the shape determination section ₂₀₂ .

First, in the separate payment mark detection unit ₂₀₁ ,
50 is a counter which counts the scanning clock signal _S1 output from the control section (not shown) corresponding to each bit within one scan of the line array 2 in the first reading section 1. Ori...
The count contents are supplied to latch circuits 51 and 52, respectively. Further, 53 is a flip-flop circuit (hereinafter abbreviated as FF circuit) to which the output L of the line array 2 is supplied. The FF circuit 53 is set when a black block signal is output from the line array 2, and remains in a reset state unless a black block signal is output, and is reset prior to one scan.

In this way, the output of the FF circuit 53 is supplied to the latch circuit 51, and the FF
When the circuit 53 enters the set state, the counter 5
The count content of 0 is latched in the latch circuit 51. In other words, the content of the latch circuit 51 is the coordinate y _o1 in the Y direction of the black block of the toll payment mark E that first appears within one scan, as shown in FIG. Further, the output L of the line array 2 is supplied to the latch circuit 52, and each time a black block signal is output from the line array 2, the count contents of the counter 50 are sequentially latched to the latch circuit 52. It is becoming more and more common.

In other words, the content of the latch circuit 52 is the coordinate y _o2 in the Y direction of the black block of the toll payment mark E that appears last within one scan. The contents of the latch circuits 51 and 52 are then supplied to a subtracter 54, respectively. This subtracter 54 subtracts the value of y _o1 in the latch circuit 51 from the value of y _o2 in the latch circuit 52, and the subtraction result [Y _o = y _o2 − _{y o1} ] is stored in the memory 55. It's getting old. in this case,
The memory 55 stores the subtraction results of the subtracter 54 for each scan in response to a 1-scan end clock signal S2 outputted from a control section (not shown) for each scan of the line array ₂ in the first reading section 1. I'm starting to remember things.

Further, 60 is a counter which counts the one-scanning end clock signal _S2 .
The count contents are supplied to latch circuits 61 and 62, respectively. Also, 63 is
The output of the FF circuit 53 is supplied to the FF circuit. The FF circuit 63 is set in conjunction with the setting of the FF circuit 53, and continues to maintain its set state regardless of the end of one scan. In this way, the output of the FF circuit 63 is supplied to the latch circuit 61, and when the FF circuit 63 enters the set state, the count contents of the counter 60 are supplied to the latch circuit 61.
It is now latched to 1. That is, the content of the latch circuit 61 is the coordinate _x1 in the X direction of the black block of the toll payment mark E that first appears in FIG. Also, the above FF
The output of the circuit 53 is supplied to the latch circuit 62, and each time the FF circuit 53 is set, the count contents of the counter 60 are sequentially latched into the latch circuit 62. In other words, the content of the latch circuit 62 is the coordinate x _l in the X direction of the black block of the toll payment mark E that appears last. The contents of the latch circuits 61 and 62 are the subtracters 64 and 62, respectively.
It is now being supplied to This subtractor 64
is to subtract the value of x ₁ in the latch circuit 61 from the value of x _l in the latch circuit 62, and the subtraction result [A=x _l −x ₁ ] is supplied to the arithmetic circuit 70. .

Therefore, the arithmetic circuit 70 calculates the circle formula [x ²
+y ² = r ² (r is the radius)], the right side of [Y _o /2 = √(2) ² − ( _o −2) ² ] is determined by the subtraction result A supplied from the subtractor 64. It is now calculated. in this case,
x _o is a coordinate indicating the scanning position in the X direction with the coordinate x ₁ as the reference position, and is obtained by the subtraction result A. Furthermore, the arithmetic circuit 70 reads the subtraction result _Yo stored in the memory 55 in response to the read command J, and uses the subtraction result _Yo and the above calculation result to obtain [Y _o /2=√(2) ² −( _o −2) ² ] is satisfied, and if it is satisfied, an output H (logic “1”) indicating that the separate postage mark E is present in the upper right corner of the postal item P is output. signal) is supplied to one input terminal of the AND circuit ₂₀₃ .

On the other hand, in the shape determination section ₂₀₂ , 80 is a connection circuit that connects the line array 2 in the first reading section 1.
The output L of is supplied. This connection circuit 80 is connected to one
By sequentially holding the coordinate positions of the black blocks that appear in each scan and sequentially connecting the black blocks that appear in each of the held scans, the coordinate positions of the black blocks that appear in each scan are successively connected, so that the coordinates of the black blocks that appear in each scan are sequentially connected. The upper outer circumference line E ₁ , the inner straight line E ₂ and the lower outer circumference line E ₃ of the toll payment mark E are electrically formed. In FIG. 6, the number of black blocks in the direction of the arrow shown by the two-dot chain line with respect to the charge payment mark E formed by the connecting circuit 80 is calculated by the counter 8.
It is now counted as 1. In other words,
In this case, the upper line of the outer periphery at the separate payment mark E
The counter 81 counts the black blocks of E ₁ , the inner straight line E ₂ , and the lower outer circumference line E ₃ , so that the count value of the counter 81 becomes "3". The count contents of this counter 81 are supplied to a matching circuit 82. This matching circuit 82 determines whether or not the information corresponding to the numerical value "3" supplied from a control circuit (not shown) matches the content of the counter 81, for example, and if they match, An operation command is issued to the counter 83. This counter 83 operates in response to an operation command from the coincidence circuit 82, and calculates the length of each line E ₁ , E ₂ , E ₃ in FIG. It is detected by counting the clock signal _S2 at the end of one run, and the content of the count is sent to the comparator 8.
4. This comparator 84 is supplied with numerical information "A/2" corresponding to the radius of the separate payment mark E from the arithmetic circuit 70 in the separate payment mark detection section ₂₀₁ . When the count content of the counter 83 becomes larger than 2'', that is, when the shape of the toll payment mark E in a certain direction corresponds to a predetermined size, a logic ``1'' signal is output. ing. The output of this comparator 84 is supplied to the other input terminal of the AND circuit ₂₀₃ . Therefore, the AND circuit 20
₃ , when the shape determination unit ₂₀₂ determines that a shape that is considered to be a postage mark E in a certain direction is present on the postal item P, the postal payment mark detection unit ₂₀₁ determines that the postage mark E exists on the postal item P. When it is detected that the toll payment mark E is definitely present on the top, a logic "1" signal is output. That is, the logic "1" signal output from the AND circuit ₂₀₃ indicates that the character line direction (recording direction of the postal code N) on the postal item P is in the horizontal position horizontal writing state. Furthermore, in this case, if the AND circuit ₂₀₃ does not output a logic "1" signal, this indicates that the character line direction (recording direction of the postal code N) on the postal item P is vertical and horizontal writing. be.

Therefore, now, when the mail P is conveyed in the direction of the arrow a and corresponds to the first reading section 1, the first reading section 1 scans the top of the mail P, and the output is in the character line direction. The signal is supplied to the discrimination circuit 20. Then, the character line direction determination circuit 20 determines the character line direction of the mail P. In other words,
It is determined that the recording direction of the postal code N on the postal item P is horizontal writing. On the other hand, when the mail P corresponds to the second reading unit 11, the postal code N on the mail P is read. Then, in the recognition section 30, the read postal code N is recognized according to the determination result of the character line direction determination circuit 20. Therefore, there is no need for the operator to visually judge the recording direction of the postal code N, and it is possible to improve not only the processing speed for character reading but also the reading rate.

Note that this invention is not limited to the above-mentioned embodiments, and it goes without saying that various modifications can be made without departing from the gist of the invention.

As described above, according to the present invention, the above-described configuration utilizes the fact that the character line direction on the postal item P corresponds to the shape of the separate postage mark, and detects the separate postage mark on the postal item. , the length of the inner straight line is detected by determining the shape of the separate charge mark by determining the number of times that the outer circle of the separate charge mark and the inner straight line are detected simultaneously, and the detected length is calculated by the separate charge mark detection unit. Since the direction of the separate fee payment mark is determined from the radius of the detected outer circle, even if the separate fee payment mark is affixed at a slight angle to the mail item, the separate fee payment mark will not appear on the mail piece. It is possible to determine in which direction the mail is attached with respect to the transport direction, and it is possible to provide a character line direction determination circuit that can improve the processing ability of mail.

[Brief explanation of the drawing]

Figures 1a and 1b are diagrams showing an example of printed mail, Figure 2 is a block diagram of an optical character reading device using the character line direction discrimination circuit of the present invention, and Figures 3 to 6 are diagrams showing this example. Fig. 3 shows an example of a mail item, Fig. 4 shows an overall configuration, Fig. 5 shows a scanning state for a postage mark, and Fig. 6 shows an example of the invention. It is a figure which shows the separate payment mark formed in a shape determination part. 20...Character line direction determination circuit, ₂₀₁ ...Charge payment mark detection unit, ₂₀₂ ...Shape determination unit, ₂₀₃ ...Gate circuit, P...Postal item, E...Charge payment mark,
E ₁ ... Upper outer circumference line, E ₂ ... Inner straight line, E ₃ ... Lower outer circumference line.

Claims (1)

[Claims] 1. An optical character reading device that has first and second reading sections that are sequentially provided along the transport direction of the mail and reads and scans the transported mail, and uses the output of the second reading section as a reading signal. A postage mark detection unit that determines the diameter of the postage mark on the postal item based on the output of the first reading unit and detects the presence of the postage mark based on the diameter; a forming part that forms the shape of an outer circumferential circle and an inner straight line of a separate postage mark on the postal item;
A length detection unit detects the length of the inner straight line by determining the number of times the formed outer circle and inner straight line are detected simultaneously, and a direction of the separate payment mark from the detected length and the radius of the outer circle. and a gate circuit that determines the direction of character lines on a mail piece based on the output of the postage mark detection unit and the output of the shape determination unit. .