JPH0652342A - Bar code detecting system - Google Patents

Abstract

PURPOSE:To easily change a program by making the detecting system a table registering system with a pitch between respective bar codes as a reference. CONSTITUTION:Mask data are prepared based on a detected start bit (102) and the start bit investigates pits from the head of input data. When the two bits of '1' are continued, the bit of this second '1' is defined as the start bit and with this start bit as a reference position, the mask data are prepared. Next, data retrieval is performed by referring to a table corresponding to these mask data (103,) this result is registered (104) and two bars are detected including the start bit on this stage. Then, it is investigated whether all the data are completely checked or not (105) and when all the data are completely checked, processing is finished. When the check is not completed, the preparation of the next mask data corresponding to the latest data (106) is started. When the mask data are '00111000', for example, a value '10H' of a position and presence '1' of the bar can be provided from the table.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a system for detecting a bar code by a signal input from an image input device in a postal automation device or the like.

[0002]

2. Description of the Related Art A bar code used in a postal automation device indicates information depending on whether or not bars having a uniform width are arranged at regular intervals (pitch).

In this type of bar code detection method, an input signal of a certain number of bits (hereinafter referred to as a new input signal) input by scanning the bar code from the image input device.
Is processed by the input signal (old input signal) input last time, and at the same time, the presence or absence of the bar code is determined.

A conventional technique will be described with reference to FIG. The new input signal input from the image input device is first divided into 9 types of jump destinations according to the contents of the upper 4 bits of the old input signal, and the new input signal is processed by each jump destination.
As a processing method, since the bar code interval is constant, when it is judged that the bar code is present, the position of the new input signal is masked to correct the sampling deviation and the signal disturbance due to the ink scattering.

FIG. 6 shows an example of the processing method. For example,
Forcibly sets the 0th and 7th bits to "0" according to the old input signal
(No data) and the new input signal is registered as it is for other bits. The 9 types of jump destinations divided by the upper 4 bits of the old input signal are then divided into the respective jump destinations (5 types of jump destinations per type) by the data of the lower 4 bits, and the new input signal is processed again. , The processed signal is registered as the old input signal and at the same time the presence / absence of the barcode is determined.

[0006]

In this conventional bar code detection method, the pitch of the bar code is printed because the program structure is complicated and a large number of branches are made in the program according to the input data. If it becomes longer or shorter due to problems on the transport path or because it is printed by another model, it is very difficult and complicated to read those bar codes because it requires a large change in the program. .

[0007]

According to the bar code detecting method of the present invention, even if the bar code pitch changes a little, the bar existing position is periodic. Therefore, the bar detected first is used as a reference. Input the data for detecting the next bar as, and convert this data to the information of the next reference position and the presence or absence of the bar by the preset table, and similarly detect the bar while shifting the reference position. Works like.

[0008]

Embodiments of the present invention will now be described with reference to the drawings. First, according to the flow of FIG. 1, a first embodiment will be described with reference to FIGS. 2 to 4.

First, the bar code is read by the bar code reader and input as binary data (101). As shown in FIG. 4, the bar code targeted by the present invention is such that bars having a single pitch are arranged in parallel, and information is shown by the intervals between the bars. This bar code is scanned in a direction perpendicular to the bar, and is input as binary data indicating "0" where the bar is not "1". In particular, in this embodiment, the timing is set so that three "1" s are input when one bar is scanned. By scanning the barcode, the input data as shown in FIG. 4 is obtained. This input data includes an error at the time of input, a slight variation occurs in the interval between the bars, and noise indicated by N due to dirt on the bar code is included.

Next, a start bit is detected, and mask data is created based on this start bit (10
2). For the start bit, the bit is examined from the beginning of the input data, and when two "1" s are consecutive, the second bit of "1" is used as the start bit. This start bit indicates the detection of the first bar of the bar code. In FIG. 4, the bit indicated by (1) is the start bit. Mask data is created using this start bit as a reference position. This mask data is intended for 8-bit input data from the input data of the 4th bit to the input data of the 11th bit counted from the start bit.
In FIG. 4, the input data in the range (2) is obtained as mask data. The number is displayed in octal and indicates the number of bits from the reference position. Next, a data search is performed by referring to the table using this master data (10
3). A specific example of this table is shown in FIG. This table has two numerical values for each value of the mask data. These two values are a value indicating the presence or absence of a bar (lower row) and a value indicating its position (upper row). The value indicating this position serves as a reference position for inputting the next mask data. The value at this position is shown in hexadecimal in FIG. 2, and this value is 8 when converted to binary.
Only one bit is indicated by a value of "1". This "1" bit indicates the position in the mask data.
FIG. 3 shows this correspondence. In FIG. 4, the mask data of (2) is “00011100”.
Referring to the table of FIG. 2 with this value, the position is “08H”
The presence / absence of a bar is "1", indicating that there is a bar.
That is, the presence of the bar is detected at the position where the number is "0".

Then, the result is registered (104). At this stage, two bars including the start bit are detected.

Then, it is checked whether the check of all the input data has been completed. If all the check of the input data have been completed, the processing is ended, and if not completed, the next mask data creation (106) is started.

The next mask data is similarly created based on the reference position obtained in the previous process (106).
Since the bar was detected at the number "0" in the previous processing, mask data is obtained from the input data of 8 bits from the fourth position from this position. This mask data falls within the range of (3) in FIG. This mask data is "00111000", and the position value "10H" and bar existence "1" are obtained from the table. This position corresponds to the position number 7. The same process is repeated thereafter. The mask data obtained next is the input data obtained in the range of (4) in the range from the 4th bit to the 8th bit after the number 7 in (3). This mask data is all 0s. The position of this all 0 is 08 according to the table of FIG.
H indicates no bar. In the mask data in the next range (5), "1000011" with noise N at the beginning is included.
0 "is obtained. This data has the position 0 in the table.
2H indicates that there is a bar. Noise N has been removed from the values in this table. With the above operation, the presence / absence of a bar is registered as 1, 1, 1, 0, 1, and it can be recognized that there are three bars in succession and one bar at an interval.

[0014]

As described above, according to the present invention, by adopting the table registration system with the pitch between the bar codes as a reference, it is possible to easily deal with the case where the bar code pitch is long or short. The effect is that the program can be changed easily.

[Brief description of drawings]

FIG. 1 is a flowchart of an embodiment of the present invention.

FIG. 2 is a table of an embodiment of the present invention.

FIG. 3 is a diagram showing mask data according to an embodiment of the present invention.

FIG. 4 is a schematic diagram illustrating an operation in the flowchart of FIG.

FIG. 5 is a flowchart of a conventional technique.

FIG. 6 is a schematic diagram of data processing of a conventional technique.

Claims (1)

[Claims] 1. A bar code reading device for scanning a paper sheet and detecting a printed bar code, wherein a binarized image obtained from an image input device for scanning the paper surface is input to convert the old binarized image. A bar code detecting method comprising means for detecting presence / absence of a bar code based on a data on / off table retrieved based on an image.