JP2773438B2 - Barcode reader - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a POS (Point of Sal
e) Bar code readers used in terminals and the like.

[0002]

2. Description of the Related Art A stationary bar code reader emits a laser beam from a reading window, scans a bar code printed or affixed to a product moved by an operator on the reading window, and uses the reflected light as an electric signal. Convert to and read the barcode. Generally, in a bar code reading device for a POS terminal, the movement of a product is manually performed by an operator. Because of this, the time to pass over the reading window is limited, and the speed of the scanning beam is high, so that the demodulation processing for restoring the read barcode content is performed by hardware, and this hardware uses the barcode. And is configured to read only one type of barcode.

In recent years, there has been a demand for stationary bar code readers to read various types of bar codes.
This is because, in addition to superstores that require conventional reading speeds, department stores that use barcodes different from barcodes used for food etc. also require high reading speeds and hands-free, This is because a barcode reader has come to be used.

[0004]

For this reason, in order to read various types of bar codes and to demodulate the contents, it is sufficient to configure hardware for each type of bar codes. The size and cost increase. The present invention has been made in view of the above problems,
It is an object of the present invention to provide a barcode reading device that enables demodulation processing by firmware by extracting only a barcode data group from data read by a barcode detection unit by hardware.

[0005]

FIG. 1 is a diagram illustrating the principle of the present invention. In FIG. 1, reference numeral 101 denotes a bar code detection unit which scans a bar code and reads it. Reference numeral 102 denotes a first storage unit for storing data read by the barcode detection unit 101. Reference numeral 103 denotes a barcode recognition unit that recognizes barcode data from the data read by the barcode detection unit 101 and reads the barcode data from the first storage unit.
The bar code data is constituted by hardware, and the recognized bar code data is stored from the first storage unit 102 to the second storage unit 104. A bar code demodulation unit 105 reads out the bar code data stored in the second storage unit 104 and performs a demodulation process by firmware processing.

Further, the first storage unit 102 is constituted by a ring buffer, and is overwritten until a bar code portion is detected.

Further, a set of a barcode recognition unit 103 and a second storage unit 104 is provided for each type of barcode.

Further, of the pair of the barcode recognition unit 103 and the second storage unit 104 provided in this way, only the pair corresponding to the type of barcode desired to be read is made valid.

The bar code recognition section recognizes a bar code data group by detecting a start section and a stop section of a corresponding bar code type.

[0010]

With the above arrangement, the data read by the barcode detecting section 101 is stored in the first storage section 102, and the barcode recognition section 103 recognizes the barcode data. Only the second storage unit 10
Stored in 4. The barcode demodulation unit 105 reads out the barcode data from the second storage unit 104 and performs a demodulation process. As a result, only the barcode data needs to be demodulated, so that the processing amount is small and no problem occurs in terms of time even if the processing is performed by the firmware.

Further, by configuring the first storage unit 102 as a ring buffer, it is possible to overwrite data before bar code data not stored in the second storage unit 104, so that the storage capacity of the first storage unit 102 is reduced. can do.

Also, a set of a bar code recognition unit 103 and a second storage unit 104 is provided as hardware for each type of bar code, and the first storage unit 102 and the bar code demodulation unit 105 are provided by being commonly used. It is possible to perform the demodulation processing of the bar code types by the number of sets. In this case, if only a set of bar code types desired to be read is activated effectively, erroneous reading by other types of bar codes can be prevented.

The barcode recognition section recognizes a barcode data group by detecting a start portion and a stop portion corresponding to a barcode type.

[0014]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 2 is a diagram showing the configuration of the stationary scanner device of the present embodiment. This device comprises an optical system and a control system. In the optical system, 1 is a laser unit for generating a laser beam, 2 is a laser control circuit for controlling the laser unit 1, and 3 is a laser unit 1.
An optical unit that scans a bar code with a laser from a polygon mirror, 4 is a motor that rotates the polygon mirror,
5 is a photodetector for detecting the laser reflected by the barcode,
Reference numeral 6 denotes an amplifier circuit for amplifying the detected data, and reference numeral 7 denotes an A / D circuit for digitally converting the amplified data. Reference numeral 8 denotes an LED lamp for notifying the operator of the reading result, and reference numeral 9 denotes a speaker for generating a sound for notifying the operator that the reading of the barcode has been completed. The control system includes a scanner control circuit 10 for controlling the optical system, a demodulation circuit 11 for demodulating A / D converted data to restore the meaning represented by the barcode, and an I / F control for interfacing with the POS terminal. It is composed of a unit 12.

FIG. 3 is a block diagram showing the configuration of this embodiment. In FIG. 1, a CPU 13, a ROM 14, and a RAM 15 perform demodulation of a bar code, optical system interface control, POS interface control, and the like. Reference numeral 16 denotes an POS interface unit that interfaces with a POS terminal 18 via a driver / receiver 17. Reference numeral 19 denotes an optical system control unit which controls the optical system 21 via a driver / receiver 20 to perform an interface. A bar width counter 22 counts the bar width of the bar code data read by the optical system 21 to obtain the bar width. Reference numeral 23 denotes a buffer control unit which stores the bar width count data in a bar width count data primary storage buffer 24, and uses a built-in start / stop detection circuit to determine the start and stop portions of the bar code from the bar width count data. The barcode data is detected and recognized, and the recognized barcode data is stored in the bar width count data buffer 25 from the bar width count data primary storage buffer 24.

The operation will now be described with reference to FIGS. FIG. 4 shows a flow chart of the bar code demodulation, and FIG. 5 shows a situation where the laser beams A and B scan over the product on which the bar code is printed. The laser beam emitted from the laser unit 1 is reflected by the polygon mirror of the optical unit 3 and scans a bar code. By this scanning, not only bar codes but also peripheral print characters and the like (hereinafter referred to as dust data)
Is also detected by the photodetector 5 (step 40), converted to a white / black signal, amplified by the amplifier circuit 6, and converted to a digital signal by the A / D circuit 7 (step 41).
The bar width is counted by 22 and the bar width is obtained. (
Step 42).

The buffer control unit 23 stores the bar width count data counted by the bar width counter 22 in the bar width count data primary storage buffer 24. The bar width count data written in the buffer 24 includes not only a bar code portion but also dust data in which characters and the like printed around the bar code are black and white information. The buffer control unit 23 detects a bar code data group having a bar code start part and a bar code stop part from the data stored in the buffer 24, and reads the bar code count data from the bar width count data primary storage buffer 24. The data group is stored in the bar width count data buffer 25.

Buffer for primary storage of bar width count data
Since garbage data is also stored in 24 as described above,
If a lot of characters such as product descriptions are written around the barcode, the garbage data increases and the buffer often fills up quickly. For this reason, in this embodiment, the main buffer 24 is a ring buffer as shown in FIG. Since the time for transferring one data from the bar width count data primary storage buffer 24 to the bar width count data buffer 25 is earlier than the time for writing one data to the bar width count data primary storage buffer 24, the operation is started. The bar code data for which the portion and the stop portion are detected are transferred to the bar width count data buffer 25, so that overwriting can be performed, and the buffer 24 does not become full.
It is sufficient if the maximum number of barcodes to be read can be stored as the capacity, and the storage capacity can be reduced.

FIG. 7 is a diagram showing storage areas of the bar width count data primary storage buffer 24 and the bar width count data buffer 25. In this embodiment, the buffer control unit 23 has a start / stop detection circuit for each barcode type so that two types of barcodes can be read simultaneously, and the bar width count data corresponding to the start / stop detection circuit is provided. It has buffers 251,252. The two types of barcodes are called barcode 1 (for example, UPC barcode) and barcode 2 (for example, CODE128 barcode).
, The bar width count data primary storage buffer 24
Stores two bar codes 1 and 2 and dust data (step 43). When the buffer control unit 23 detects the start and stop portions of the bar code, the bar width count data is stored in the primary storage buffer 24. The data is transferred to the bar width count data buffer 25. That is, the bar code 1 is stored in the bar width count data buffer 251, and the bar code 2 is stored in the buffer 252 (step 44). The buffers 251, 252 are
A flag may be used, or the memory space may be divided and configured with the same buffer.

Next, data read from the bar width count data buffer 25 is subjected to final dust data deletion by a firmware filter (step 45). In the hardware of this embodiment, the start margin (start part), end margin (stop part), and the number of elements between
(Number of white and black bars) Since only check is performed, garbage data is also included. Therefore, various checks specified in the code are performed by the firmware, final filtering is performed, and all garbage data is deleted. In this manner, the B beam data and surrounding data in FIG. 5 are removed, and only the bar code portion of the A beam is extracted. One of the checks is a check of the adjacent character length of the barcode by the firmware.

After only the bar code portion is extracted in this way, the bar code is demodulated (step 46). When reading one barcode, the barcode data is input many times, so steps 40 to 46 are repeated many times. In this case, if the demodulated data is different from the previously input data and different data is demodulated, all the different data are buffered (step 47). Since the demodulated data may include misread data, various checks (such as those defined in the code)
For example, a check using a modulus 10 check code) is performed, and data that passes all the checks is adopted as a bar code read value (step 48).

As described above, according to the present embodiment, since the demodulation processing is performed by the firmware, the circuit scale of the hardware is reduced. Since the demodulation unit is configured by firmware, the demodulation logic can be easily changed. By making the buffer 24 for the bar width count data primary storage a ring buffer, the buffer 24
Can be prevented from becoming full. In the present embodiment, two types of bar code circuits are used. However, more types of bar code circuits are provided, so that various types of bar codes can be read. By operating only the bar code type circuit to be read, it is possible to prevent erroneous reading by a circuit that processes a code other than the code to be read. Since only the barcode data is transferred to the bar width counting buffer 25, the amount of dust data is reduced, and subsequent processing is facilitated. By employing the ring buffer described in (1), the capacity of the bar width count data primary storage buffer 24 can be reduced.

[0023]

As is apparent from the above description, according to the present invention, since only the barcode is extracted from the read data by the hardware, the demodulation processing by the firmware can be temporally performed, and various types of barcodes can be processed. Since processing can be performed by firmware, it is not necessary to configure all circuits corresponding to the types of barcodes with hardware, so that the circuit scale can be reduced and the cost can be reduced.

[Brief description of the drawings]

FIG. 1 is a principle diagram of the present invention.

FIG. 2 is a configuration diagram of a stationary scanner according to an embodiment of the present invention.

FIG. 3 is a block diagram illustrating a configuration of the present exemplary embodiment.

FIG. 4 is an operation flowchart of the present embodiment.

FIG. 5 is a diagram for explaining barcode scanning by a laser beam.

FIG. 6 is a diagram showing a ring buffer.

FIG. 7 is a diagram illustrating a storage area of a storage unit that stores barcode read data.

[Explanation of symbols]

 13 CPU 14 ROM 15 RAM 19 Optical system controller 20 Driver / receiver 21 Optical system 22 Bar width counter 23 Buffer controller 24 Bar width count data primary storage buffer 25 Bar width count data buffer

Claims (5)

(57) [Claims] 1. A bar code detection unit for reading a bar code, a first storage unit for storing data read by the bar code detection unit, and a bar code characteristic selected from the data read by the bar code detection unit. The bar code data group is recognized by detecting the portion, and the bar code data group is
A barcode recognition unit configured by hardware, read from a storage unit, a second storage unit storing barcode data read from the first storage unit by the barcode recognition unit, and the second storage A bar code reader comprising: a bar code demodulation unit that reads bar code data stored in a unit and performs demodulation processing by firmware processing. 2. The bar code reader according to claim 1, wherein said first storage section is constituted by a ring buffer. 3. The barcode reading device according to claim 1, wherein a set of the barcode recognition unit and the second storage unit is provided for each type of barcode. 4. A bar code recognition for each bar code type.
4. The method according to claim 3, wherein, of the pair of the recognition unit and the second storage unit , only the pair of the barcode recognition unit and the second storage unit corresponding to the type of the barcode desired to be read is made effective. Barcode reader. 5. The barcode reader according to claim 1, wherein the barcode recognition unit recognizes a barcode data group by detecting a start portion and a stop portion of a corresponding barcode type.