JPH01307885A - Code reader - Google Patents

Abstract

PURPOSE:To reduce the burden on an information processor and to read a code with a high precision by outputting a bar code in accordance with the number of times of continuous coincidence between present and preceding decoded bar codes and regarding equal bar codes different in position as different codes based on a bar space counted value. CONSTITUTION:Outputs of first and second data memories 62 and 64 are supplied to a first comparator 65, and this comparator 65 detects coincidence between present and preceding decoded bar codes. When the number of times of continuous coincidence counted by a data counter circuit 66 reaches a prescribed value, a signal (g) to supply the present decoded bar code to the information processor is outputted from a data counter comparator 68. When the ratio of the present bar space counted value to the preceding bar space counted value is a prescribed value or lower, a signal to regard equal bar codes different in position as different bar codes is outputted from a second comparator 77 to which outputs of a bar space counter memory 72, a preceding bar space counter memory 74, and a constant divider 76 are supplied; and thus, the burden on the information processor is reduced, and erroneous read is prevented to improve the bar code read precision.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention converts a barcode symbol displayed on a medium into an electrical signal using a photoelectric converter, and decodes it into data that can be processed by an information processing device. Reducing the amount of output data of a code reading device that uses a self-scanning photoelectric converter, in particular, reducing the burden on the information processing device that receives and receives this output data, The present invention relates to a code reading device that is capable of automatically distinguishing and reading barcode codes of the same configuration but at different display positions.

[Prior Art] As a means of inputting data into an information processing device such as a computer, a barcode code input method is used in which a barcode code is created using black bars and white spaces, and this barcode code is read by a photoelectric converter. Ka system is known. This type of barcode entry system significantly reduces data entry time compared to input using a keyboard, etc.
The field of application is expanding day by day because input operations are easy, there are few input errors, and there are no mechanical parts in the photoelectric converter that is the input device, so there are fewer failures.

For example, product type, price, number of sales, and sales region.

This barcode code is used for various information management using various data such as sales management mainly using data such as VTR program reservations and room cooler control, and for operating and checking the functions of various industrial and consumer equipment. Input systems are widely used.

The barcode code standard used in the barcode code input system is the Japanese Industrial Standard JIS, B9550-
1978, or July 1, 1984, published by CQ Publishing, Transistor Technology Special Issue “Sensors, Interfacing J”
N04. This is explained in detail on pages 179 to 199, ``Production of Barcode System.''

FIG. 3 is an explanatory diagram of this barcode symbol and its read waveform, where (a) is the displayed barcode symbol, (b)
) is a read waveform diagram obtained by scanning the barcode in (a) in the direction of the arrow with a photoelectric converter. In addition.

In (a), S is a start code or a stop code, and is the initial state set of the code reader or the bar/stop code.
Used for space criteria. And (a
), C is a message code indicating the information (message) of this barcode, and (a) shows an arrow and a code that can be read in the opposite direction to the arrow.

A code reading device that reads such a code uses an IT H signal as shown in FIG.
The width between adjacent changing points (edges) of the two-level waveforms n and u L II is counted as the number of clock signals, and information C of the barcode is decoded based on the count value (hereinafter referred to as decoding). For example, a self-scanning photoelectric converter is used as the photoelectric converter.
Binary data in which information C of the barcode is decoded is supplied from this code reading device to an information processing device. And code reading devices using self-scanning photoelectric converters.

One barcode symbol is scanned thousands to hundreds of times.

By decoding, the reading probability and accuracy are increased.

[Problems to be Solved by the Invention] This type of code reading device using the self-scanning photoelectric converter described above scans one barcode code many times, ranging from several thousand times to several hundred times, and then decodes it. ing. However, transmitting the same code after the read code has been correctly decoded unnecessarily places a burden on the information processing device and wastes the resources of the information processing device.

On the other hand, the barcode codes used in barcode code input systems are prone to code errors due to the adhesion of dirt, and the light reflectance of the white bar may decrease depending on the printing quality, or the clarity of the bar width may be affected. may change, or there may be voids within the black bars or spots within the white bars, which are also likely to cause code errors. In addition, code reading devices used in barcode code entry systems are unstable immediately after power is turned on, and this may cause malfunctions, or improper operation may cause the angle of incidence to fluctuate. This may cause malfunctions.

Therefore, in this type of code reading device, it is necessary to perform a reading operation with high reading accuracy and without decoding errors.

Furthermore, barcodes are used to create data tables such as product type, price, sales volume, sales destination, etc., and this data table is read and processed to analyze sales performance and formulate the next sales plan. etc.

In order to handle many types of information or for reasons of convenience, barcode codes with the same configuration but different information may be used for data processing. In such a case, barcode codes having the same structure and different types of information are arranged, for example, in the vertical direction of the data table, and the difference in information is distinguished and processed depending on the arrangement position.

In this case, if the code reading device itself could distinguish between the differences in information between barcode codes with the same structure located at different positions in the data table (for example, different row positions in the vertical direction), processing would be more efficient. It's convenient.

It is an object of the present invention to solve the problems of the prior art described above, to read barcode symbols with high reading accuracy, to reduce the burden on the information processing device side for processing decoded data, and to reduce the burden on information processing equipment that processes decoded data. An object of the present invention is to provide a code reading device configured to distinguish and process codes.

[Means for Solving the Problems] In order to achieve the above object, the present invention includes a first data memory for storing currently decoded data and a first data memory for storing previously decoded data on the output side of the decoding unit. 2 data memory, the data stored in the first data memory and the second data memory;
a first comparator that compares the data stored in the data memory of the data memory; a second comparator that detects that the number of bars and/or spaces is less than or equal to a certain ratio with respect to a predetermined value; When the comparison by the first comparator successively matches and reaches a predetermined number of times, the data stored in the first data memory is transferred to the information processing device as decoded data, and the data stored in the first data memory is transferred to the information processing device as decoded data. The present invention is characterized in that an output control unit is provided that includes means for transmitting the barcode symbol as separate information to the information processing device when the comparison is below the above-mentioned certain ratio.

[Operation] When the self-scanning photoelectric conversion section starts reading the barcode symbol displayed on the medium, the edge detection section and the counter section operate based on the output signal of this self-scanning photoelectric conversion section. The barcode symbol is decoded by the decoding section based on the output signals of the edge detection section and the counter section.

The data decoded by the decoding section is input to the output control section, the first data memory of the output control section stores the currently decoded data, and the second data memory stores the previously decoded data. .

In addition, the first comparator provided in the output control section allows
The data stored in the first data memory and the data stored in the second data memory are compared, and the number of bars and/or spaces is compared with a value based on a predetermined value set in advance by a second comparator. .

Then, the data stored in the first data memory and the data stored in the second data memory are compared by the first comparator.
When a predetermined number of consecutive matches is reached, the data stored in the first data memory is transferred to the information processing device as decoded data. Furthermore, when the comparison by the second comparator is less than or equal to a predetermined value, even if the barcode codes have the same structure, they are automatically distinguished as separate information and transferred.

In this way, in the present invention, even if barcodes have the same structure but have different arrangement positions, they are distinguished as separate information and read with high accuracy, and the obtained decoded data reduces the burden on the information processing device. In this way, the information is supplied to the information processing device.

[Embodiments] Nine embodiments of the present invention will be described below with reference to FIGS. 1 and 2.

FIG. 1 is a block diagram showing the configuration of an embodiment of a code reading device according to the present invention, and FIG. 2 is a block diagram showing the specific configuration of the output control section in FIG. 1.

In FIG. 1, 1 is a photoelectric conversion section, 2 is an edge detection section,
3 is a counter section, 4 is a start/stop determination section, 5 is a decoding section, 6 is an output control section, and 7 is a switch.

In the figure, a photoelectric conversion unit 1 is a self-scanning line sensor consisting of a photoelectric conversion element array such as a CCD.

Equipped with an imaging optical system, a digitizer, etc., it photoelectrically converts the barcode displayed on the medium into "H" or II L I
It is given to the edge detection section 2 as a binary signal a of I. This edge detection unit 2 detects that the binary bell signal a is “HI”.
A change point where T→(tL" or RL"→"H") is detected and this is applied as an edge detection signal to the counter section 3, start/stop determination section 4, and decoding section 5.

The counter section 3 is cleared to O by the input of this edge detection signal S, and counts the clock signal CL from a clock signal generation means (not shown) between two adjacent edge signals inputted from the edge detection section 2, A count signal C indicating a count value is given to the start/stop determining section 4 and the decoding section 5.

The start/stop determination unit 4 detects the start code S shown in FIG. 3 from the edge detection signal and the count signal C to perform a start determination. If the start determination is not satisfied, the signal give to Then, the stop code S following the message code C input after the start determination is detected, and when the stop condition is satisfied, a signal e is given to the decoding section 5.

Furthermore, upon receiving the edge detection signal S, the decoding section 5 takes in the count signal C from the counter section 3 and performs decoding processing, and when the decoding is performed correctly, outputs a signal i indicating success of the decoding to the control section. 6, and also supplies the decoding result data d to the output control section 6 and the switch 7. If decoding is not performed accurately in the decoding section 5, a signal r indicating decoding failure is given to the counter section 3 and the start/stop determining section 4 to reset them. Note that when the signal f is input from the start/stop determining section 4 to the decoding section 5, the count signal C taken in and stored from the counter section 3 is cleared.

Then, as will be described later, the output control unit 6 causes the first comparator 65 to compare the data so that the data stored in the first data memory 62 and the data stored in the second data memory 64 are consecutively stored at a predetermined level. If the decoded data matches the number of times, the data stored in the first data memory 62 is transferred to the information processing device as decoded data.

If the comparison by the first comparator 65 does not match a predetermined number of consecutive times, the data is not transferred to the information processing device.

The output control section 6 has a specific configuration as shown in FIG. In FIG. 2, 61 and 63 are switching devices, 62 is a first data memory that stores currently decoded data, and 6
4 is a second data memory for storing previously decoded data; 65 is a comparator for comparing the data stored in the first data memory 62 and the data stored in the second data memory 64; 6;
6 is a data counter circuit that counts the number of times that the comparison of the comparator 65 matches, 67 is a constant register that sets a predetermined number of times in advance, and 68 is a comparison between the output of the data counter 66 and the set number of times of the constant register 67. 69 is an OR circuit. Further, in FIG. 2, 71 is a bar/space counter circuit for counting edge signals, and 72 is a bar/space counter circuit 7.
73 is a switch, 74 is a previous bar/space counter memory that stores the count value of the previous bar/space counter memory 72, and 75 is a bar/space counter memory that stores a count value of 1. A constant register to be set; 76 is a divider that divides the count value of the previous bar/space counter memory 74 by a predetermined value set in the constant register 75; 77 is a bar/space counter memory 72;
The second step compares the stored count value of 76 with the calculated value of the division value 76.
It is a comparator.

As shown in FIG. 2, a first data memory 62 is connected to the switch 61, and this switch 61 is turned on by a signal i indicating successful decoding, and the data d resulting from the decoding is used as the input data d2. 1 data memory 62. The first data memory 62 stores input data d2 that is input, and provides this to a first comparator 65 and a switch 63 connected to the first data memory 62 as output data d3.

A second data memory 64 is connected to the switch 63,
An output terminal of the second data memory 64 and an output terminal of the first data memory 62 are connected to an input terminal of a comparator 65. One output terminal of the first comparator 65 is connected to one input terminal of the switch 63 and the OR circuit 69, and the signal apl is transmitted from this one output terminal to the switch 63.
When the switch 63 is turned on, the first
Data d4 corresponding to the output data d3 from the data memory 62 is input to the second data memory 64.

After data d4 (data d3 from the first data memory 62) is input to the second data memory 64 and stored as decoded data last time, this data d4 is changed to data d5.
is input to the comparator 65, and in the comparator 65,
This data d5 (previous decoded data) is compared with output data d3 (current decoded data) from the first data memory 62. As a result of this comparison, if data d3 and data d5 match, a signal cp2 is output from the other output terminal of the first comparator 65, and this signal cp2 is sent to a data counter circuit 66 connected to the comparator 65. If the comparison result is a mismatch, a signal apl is output from one output terminal of the first comparator 65.

As described above, one output terminal of the first comparator 65 is connected to one input terminal of the OR circuit 69, and the output terminal of this OR circuit 69 is connected to the data counter circuit 66. . For this purpose, the first comparator 65
If the comparison at O does not match and the signal apl is output, O
A signal j is applied from the R circuit 69 to the data counter circuit 66, and the data counter circuit 66 is reset by this signal j.

Furthermore, since the signal i indicating successful decoding is input to the data counter circuit 66, the data counter circuit 66
6 continuously counts the signal i indicating successful decoding while the signal cp2 is input, and outputs the count signal dc.
l is input to a data counter comparator 68 which is connected to a date counter circuit 66.

On the other hand, the data counter comparator 68 includes a constant register 6
A preset number of times signal r1 is input from 7,
The data counter comparator 68 compares the force, runt signal del and the number of times signal r, and turns OFF if del<rt.
If del≧r, it outputs the ○N signal g. This ON signal g turns on the switch 7 shown in FIG. 1, and the data d resulting from the decoding from the decoder 5 is transferred from the switch 7 to the information processing device as data d1. When the OFF signal 11 is applied to the switch 7, the switch 7 is turned off, so that no data is transferred from the decoder 5.

Since the data counter circuit 66 is reset when the comparison by the first comparator 65 does not match, the data counter comparator 68 selects the output data d3 of the first data memory 62.
When the data d5 in the second data memory 64 are the same data consecutively a predetermined number of times (for example, 10 times), an ON signal g is output.

On the other hand, the bar/space counter circuit 71 counts the edge signals from the edge detection section 2 shown in FIG. Counter circuit 71
The count value bcl is incremented and stored in a bar/space counter memory 72 connected to the bar/space counter memory 72. The bar/space counter memory 72 also includes a second comparator 77.
and a switch 73 are connected, and the bar/space counter memory 72 provides an output signal bc2 corresponding to the count value bcl to the second comparator 77 and the switch 73. This switch 73 is connected to the data counter comparator 68 described above.
When the ON signal g is applied, the switch 73 is turned on, and the output signal bc2 of the bar/space counter memory 72 is applied as the signal bc3 to the previous bar/space counter memory 74.

The output terminal of the previous bar/space counter memory 74 and the output terminal of the constant register 75.

The output terminal of this divider 76 is connected to the input terminal of a second comparator 77, and the second
The output terminal of the comparator 77 is connected to the input terminal of the aforementioned OR circuit 69.

Then, the output signal bc4 corresponding to the previous counter value of the bar/space counter memory 74 is divided by a predetermined value set in advance by the divider 76, and the calculated value rsl and the output signal bc of the bar/space counter memory 72 are divided by a predetermined value set in advance.
2. are compared by the second comparator 77. In this comparison, if the output signal bc2 corresponding to the counter value of the bar/space counter memory 72 is smaller than the calculated value rsl of the divider 76, the signal cp4 is output from the second comparator 77.
R circuit 69 and second data memory 64.

In response to this signal cp4, the signal j is applied from the OR circuit 69 to the data counter circuit 66, so that the data counter circuit 66 is reset and the second data memory 64 is cleared.

Since what is stored in the previous bar/space counter memory 74 is the bar and/or space count value at the time of successful decoding, the count value of the bar/space counter circuit 71 will decrease below a certain ratio of this count value. means that the number of bars and/or spaces is abnormally small.

This can occur, for example, by reading blank spaces between barcodes when sequentially scanning vertically spaced barcodes.

In this embodiment, in this case, the second data memory 64 is cleared, the data counter circuit 66 is reset, new stored data is taken in and a new operation is started, and the process that the barcode information has changed is performed. do. This results in
For example, even if barcode symbols have the same configuration, information can be clearly classified.

In this way, according to this embodiment, the data d of the decoding result output from the decoding section 5 is.

High-precision reading is performed without decoding errors under stable reading conditions in which the same data is continuously read a preset number of times (for example, 10 times), and the readings are placed at different positions with an interval maintained. Even if the barcode symbols have the same structure, the barcodes are processed separately and transferred to the information processing device as data d1.

Therefore, the data d1 is transferred so as to significantly reduce the burden on the information processing device, and the code reading is performed with high reading accuracy without decoding errors, and barcodes placed in different positions are automatically distinguished. It can be done.

Note that although the second comparator 77 is described above as counting the number of bars and/or spaces, the present invention is not limited to this, and may be configured to count bars or spaces.

[Effects of the Invention] As described above, the present invention provides a code reading device that has a self-scanning photoelectric conversion section and performs reading by scanning several thousand to several hundred times.

Data is transferred in such a way as to reduce the burden on the information processing device. In addition, barcode reading is performed under stable reading conditions in which data matches a predetermined number of times in a row, with high reading accuracy and highly reliable operation with no decoding errors. Even if the code structure is the same, the information is transferred as old information, so it is possible to efficiently aggregate and analyze information using barcodes.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of an embodiment of the code reading device according to the present invention, FIG. 2 is a block diagram showing the specific configuration of the output control section in FIG. 1, and FIG. It is an explanatory diagram of the read waveform. 1...Photoelectric conversion unit, 2...Edge detection unit, 3...Counter unit, 4...Start/stop determination unit, 5... ...Decoding section, 6.
...Output control unit, 62...First data memory, 64...Second data memory, 65...
...First comparator, 66... Data counter circuit, 67... Constant register, 68...
...Data counter comparator, 71...Bar...
Space counter circuit, 72...Bar/space counter memory, 74...Previous bar/space counter memory, 75...Constant register, 7
6...Divider, 77...Second comparator. Figure 3

Claims (1)

[Claims] A self-scanning photoelectric conversion section that converts the barcode symbol displayed on the medium into an electrical signal, and a signal indicating the edge of the bar/space of the barcode symbol is detected from the output signal of the self-scanning photoelectric conversion section. an edge detection section, a counter section that outputs the width between adjacent edges detected by the edge detection section as a count value of a clock signal, and information possessed by the barcode symbol based on the count value from this counter section. A code reading device having a decoding unit that decodes data into data that can be processed by an information processing device, the output side of the decoding unit having a first data memory that stores currently decoded data and a first data memory that stores previously decoded data. a second data memory for storing; a first comparator for comparing stored data in the first data memory and stored data in the second data memory; and a first comparator for comparing data stored in the first data memory and data stored in the second data memory; A bar that remembers the number of bars and/or spaces.
a space counter memory, a previous bar/space counter memory that stores the number of bars and/or spaces based on the edge signal used in the previous decoding, and a memory value of the bar/space counter memory that is stored in the previous bar/space counter memory; a second comparator that detects that the value is less than or equal to a predetermined ratio with respect to the value stored in the memory;
When the comparison by the comparator successively matches a predetermined number of times, the data stored in the first data memory is transferred to the information processing device as decoded data, and the comparison by the second comparator is performed. 1. A code reading device comprising: an output control section having means for transmitting the barcode symbol as separate information to the information processing device when the barcode symbol is equal to or less than the predetermined ratio.