JPH01133184A - barcode reader - Google Patents

Abstract

PURPOSE:To remove the influence of a change in speed or the variance of printing by setting a storage setting value to a threshold level at the time of rapid scanning, and at the time of slow scanning, executing prescribed operational processing to set the threshold level and to decide data. CONSTITUTION:A scanning speed detecting circuit 9H checks a scanning speed. In the slow scanning less than a prescribed value, the threshold level for deciding to '0'/'1' of a black bar 7P following a white bar 7B right of a black bar 7A as data O is processed and set by a threshold setting circuit 9J on the basis of the width value of the black bar 7A stored in a width register in a width counting circuit 1B. A trailing edge signal is generated when the black bar 7P appears after the white 7B and the white 7B width count value is stored in the width register. The circuit 1B starts the counting of the black bar 7P. Then, a threshold for deciding a white 7Q is similarly calculated and set up by a threshold setting circuit 9M on the basis of the width value of the white 7B. In the rapid scanning more than the prescribed value, previously stored corresponding data are fetched from a threshold memory 9R on the basis of the value of the width register and respective values are set as threshold levels.

Description

[Detailed description of the invention] Industrial applications The present invention relates to a barcode reading device.

BACKGROUND OF THE INVENTION In recent years, barcode reading devices have been used in combination with wireless remote control transmitters (hereinafter referred to as remote control transmitters) in home appliances, such as video tape recorders (hereinafter referred to as VTRs).
It is used to simplify various switch operations when reserving television programs. Barcode tables used for reservation operations are supplied by VTR manufacturers and magazines that carry TV program information, but barcode printing formats, printing accuracy, printing requirements, etc. vary, and barcode reading operations are difficult. At this time, reading errors and malfunctions may occur depending on the scanning start position and scanning speed at the time of input.

For this reason, the conventional remote control transmitter has a barcode input section 1, for example, as shown in FIG. Barcode decoding section 2. It has a remote control signal output section 3, a remote control transmission switch input section 4, and a buzzer output section 5, and the display surface is scanned while irradiating visible light etc. from the bar code input section 1 onto the bar code display surface 6, and the reflected light is emitted from the bar code input section 1. Read the barcode array as shown in Figure 5. The barcode display surface 6 has two types of black (bar) widths: narrow and wide. A and white (space) 7B having the two types of widths are arranged alternately according to the display content and are arranged as a barcode group 7 to represent a predetermined meaning. Of the 2 barcode groups 7, 7C is a start code section indicating the start of the barcode, 7D is a data code section, and the first data 7H is represented using five black (bars), and the next data 7
■ is represented using five white (space) lines. In Figure 5, there are two types of data, 7H and 71, but if necessary, 2X
It can be arranged to represent n types of data.

Further, 7E is a stop code section indicating the end of the barcode.

This type of barcode display method is interleaved 2-
It is called a 5-method barcode. In this method, black (bar) and white (space) are repeated alternately in the data code section 7D, and black (bar) has a meaning only with black (bar), and Father's Day (space) has a meaning with only white (space). It is a code.

Furthermore, this barcode always starts with a black bar and ends with a black bar. In addition, before the first black (bar) begins, there is always a scan start point 8 indicating the scan start position for barcode input and a start margin 7F, and at the same time, after the last black (bar) there is always a stop margin 7G. There is. Usually, this barcode is displayed on paper, a synthetic resin sheet, or other displayable surface by printing, transferring, painting, or other displayable means.

Then, in FIG. 4, the barcode decoding unit 2 uses the data stored in the barcode input unit 1 to which black (bars) and white spaces are alternately input, and performs a pass/fail check on the start code section and the data code section. The data in the data code section is separated, decoded, and stored into black bars (black bars) and white (spaces).

The remote control signal output section 3 outputs the barcode decoding section 2 when the transmission switch is input at the remote control transmission switch input section 4.
It extracts the data that has been decoded and stored, converts the data into a remote control transmission format, and sequentially outputs it as an infrared remote control signal.

The buzzer output section 5 outputs a predetermined buzzer sound when determining whether the data decoded by the barcode decoding section 2 is acceptable or when the remote control transmission switch is input.

Further, to explain the barcode input unit 1 in detail, the barcode reading circuit IA irradiates the barcode display surface 6 with visible light, converts the reflected light into an electrical signal, checks whether there is a change in the input, and reads the barcode. is read as an electrical signal, the pulse width of the electrical signal that has started reading is counted by the counting circuit IB, and the margin detection circuit IC detects the margin. Width counting circuit I
If the width value of the white (space) counted in B is a predetermined value [8 times 1 or more of the black (bar) width input immediately before, that is, when the start margin 7F (Figure 5) is recognized. , starts barcode reading, and further captures the next input signal. In the threshold setting circuit ID, the first black (bar) data input after the detection of the start margin 7F is set to 0°, the next white (space) data is set to "1", and the 0/
A value for 1 judgment, that is, a threshold for adjacent black or white data is set. When the input signal is a falling signal, the black/white data detection circuit IE detects the immediately preceding data as white data, and when it is a rising signal, the immediately preceding data is detected as black data.

The data (0/1) judgment/registration circuit IF compares the input data with the already set threshold, and when the input data is greater than the threshold, it is judged as data "1", and when it is smaller than the threshold, the data “It was determined as Oo,
register. The threshold update setting circuit IG sets a new threshold for judging the next input barcode signal based on the data judged by the data (0/1) judgment/registration circuit IF.The threshold is updated. After being set, the barcode signal that is subsequently input passes through the barcode reading circuit IA and the width counting circuit IB, and then is checked by the margin detection circuit IC to see if it is a stop margin of 7G, and the stop margin of 7G is detected. Black/white data detection circuit IE, data (0/1) I
The data is registered via the f-setting/registration circuit IF, and then returns to the barcode reading circuit IA via the threshold update setting circuit IG, whereupon the above-mentioned operation is continued. Note that the first input data passes through the threshold setting circuit ID only when the margin detection circuit IC detects the start margin 7F. The threshold setting circuit ID and the threshold update setting circuit IG set the threshold for O/1 judgment of the next data based on the input data, but since the barcodes alternate between black and white, black The data is used to set a threshold for the next white data determination, and the white data is further used to set the next black data determination piece threshold. That is, the threshold for determining the next adjacent black or white data is calculated and set based on the immediately preceding white or black data. Now, while repeating data detection and judgment,
Next, when the stop margin 7G is detected by the margin detection circuit IC, it is assumed that the barcode input has been completed, and the operation in the barcode decoding section 2 starts.

Both the start margin 7F and the stop margin 7G are
A white space (space) that is eight times or more wider than the width of the previously input black bar will be detected as a margin the next time it is input.

Problems to be Solved by the Invention Barcodes are usually provided on paper or synthetic resin sheets by printing or transfer, but when looking at an enlarged model of the display surface, as shown in Figure 6, barcodes are The black bar (formed with paint, paint, etc.) has a standard width of 7J, but its actual width is 7L, which tends to swell slightly.

On the other hand, the white (space) sandwiched between black (bars) on both sides has an actual width of 7M, which is narrower than the normal width of 7K due to the influence of the black (bars) on both sides. If adjacent black and white data are the same, their widths should not be the same.However, on a practical level, as mentioned above, there is a tendency for the widths to become wider in the printing and transfer sections, so the widths of the adjacent If you set the O/1 judgment threshold for the next data based on the immediately preceding data, depending on variations in print quality, the data may not be read correctly, leading to malfunctions. In the detection circuit IC, black (
When the white space (after the bar) is 8 or more black, it is considered to be a blank space, and this is often seen in magazines that publish TV programs, as shown in Figure 7. In the case of such a barcode display example, if the scanning speed when inputting the barcode is increased, it may not be possible to read the barcode correctly. In Figure 7, 8 is when inputting a barcode;
This is a scan start mark for a scanner (not shown). However, if you are not familiar with the input operation, you may end up scanning from a point 8N that is slightly to the left of the scan start mark 8 instead of scanning from within the scan start mark 8, and the scanning speed may also be low.
It becomes faster, slower, or unstable. Normally, when scanning starts from scan start mark 8, the input part of the reflected light is placed on scan start mark 8 (so that the next start margin 7F
is more than 8 times black, and this scanning start mark 8 and start margin 7F will not be judged as part of the data of barcode 7, but the start margin will be scanned at an increased scanning speed from X-marked point 8N, which is off the mark. Since the width count value of 7F is less than 8 times the width count value of scan start mark 8, even scan start mark 8 and start margin 7F may be determined to be part of barcode group 7 as the object. Correct data cannot be read.

As mentioned above, when inputting a barcode, conventional barcode reading devices often cause reading errors or malfunctions due to variations in the display quality of the barcode display section and the handling of the scanner, resulting in errors after the remote control is sent. As a result, the operation of the machine on the receiving side was often contrary to the user's expectations, so there was a need for a highly reliable barcode reading device that could read barcodes reliably and quickly.

The present invention takes into account the above-mentioned conventional problems and provides a highly reliable barcode reading device that is free from barcode reading errors and malfunctions.

Means for Solving the Problems The present invention has a scanning speed detection circuit, and when the scanning speed is above a predetermined value, data is detected by comparing the input data with a threshold stored in advance according to the speed. O
/1 judgment is made, and when the speed is below a predetermined value, the threshold is set after calculation in the threshold setting circuit for black or white data based on the output from the width counting circuit, and compared with the black or white input data, respectively. This is a barcode reading device that performs data O/1 determination by doing this.

Effect With the above configuration, when the scanning speed exceeds a predetermined value during high-speed scanning, the calculation process for setting the threshold is not performed.
A pre-memorized value can be immediately retrieved and used as the extraction threshold, and during low-speed scanning, the threshold setting circuit performs predetermined arithmetic processing to set the threshold and performs data O/1 judgment, making barcode reading scanning easier. It is possible to supply a highly reliable barcode reader that is not affected by variations in barcode display printing because it can respond to changes in speed and judges black or white data as 0/1 using a black or self-esteem threshold. Became.

Embodiment An embodiment of the present invention will be described with reference to FIGS. 1 to 3 of the accompanying drawings.

FIG. 1 is a block diagram of the circuit configuration of the device according to the embodiment. In the figure, the main part of the embodiment is located in the barcode input section 9, and the other blocks that are the same as those in the conventional example are given the same numbers. Grant and explain (.

The barcode input section 9 irradiates the barcode pattern (FIG. 2(A)) on the barcode display surface 6 with visible light, etc., converts the reflected light into an electrical signal, and further converts the reflected light into an electrical signal as shown in FIG. 2(B). The part that shapes the waveform into a rectangular wave signal and reads the barcode has the following configuration.

First, the width counting circuit IB counts the pulse width of the electrical signal that is started to be read by the barcode reading circuit IA, and when the input signal receives a rising signal 21 or a falling signal 20 as shown in FIG. , is a width counting circuit that stores the count value up to that point in a width register (not shown) as a black or white width value, and after storing, the count is sequentially cleared and starts counting anew from zero. .

Start margin detection circuit 9 for detecting start margin 7F
J means that the width count value of the first input white (space) data is 8 of the width count value of the black (bar) data input immediately after that.
If it is more than double, it is determined that the start margin is 7F.

Next, the threshold setting circuit 9L for the black bar) is as follows.
This circuit part uses the value of the current black bar 7A to determine the O/1 of the black bar 7P after the next white space 7B. The bar code scanning speed detection circuit 9H performs a speed check based on the bar code width, and if the width count value is less than a predetermined value (i.e., high-speed scanning), the bar code is registered in advance according to the value. The extraction threshold is immediately set from the threshold memory 9R during high-speed scanning without calculation.
When the width count value is greater than or equal to a predetermined value (ie, low speed scanning), a threshold is calculated and set by arithmetic processing based on the width count value. The threshold setting circuit 9M for white (space) uses the value of the next input white (space) 7B to set O/1 of the white (space) 7Q after the next black (bar) 7P. The scanning speed detection circuit 9H performs a speed check based on the width register value (currently a white space) and the width count value, and if the width count value is less than a predetermined value (i.e., high-speed scanning). >, the extraction threshold is immediately set from the pre-registered high-speed scanning threshold memory 9R without any calculations, according to the value.In addition, when the width count value is greater than or equal to a predetermined value (i.e., low-speed scanning scan), based on the width count value,
Calculate and set the threshold by calculation.

If the width of the white (space) that continues to enter after the last black (bar) 72 of the barcode is input to the barcode end margin detection circuit 9 is more than 8 times the width of the black 7Z, it is regarded as a stop margin 7G and the barcode is After inputting the code, the barcode decoding section 2 operates as in the conventional example.

In the black/white data detection circuit IE, the input signal is
As shown in Figure (B), when the falling signal 20 occurs, the data immediately before the falling signal 20 is detected as white (space) data, and when the rising signal 21, the immediately preceding data is detected as black (bar) data.

In the data (0/1) judgment/registration circuit, the input black or white data (width count value) has already been set by the black (bar) threshold setting circuit 9L or the white (space) threshold setting circuit 9M. When the input data is larger than the threshold (that is, when it is a wide value), it is determined as data "1" and the input data is stored as 1°. When the input data is smaller than the threshold (that is, when it is a narrow value), it is determined that the data is "0", and the input data is stored as "O".

The black (bar) threshold update setting circuit 9P sequentially updates and sets the black data for O/1 judgment of every other black data, based on the black data input immediately before, and repeats this process. When updating, like the black (bar) threshold setting circuit 9L, the scanning speed detection 9H performs a speed check based on the value of the width register, and when the width count value is less than a predetermined value (that is, high-speed scanning). is the pre-registered threshold memory 9R for high-speed scanning according to its value.
, and set the threshold immediately without any calculation processing. When the width count value is greater than or equal to a predetermined value (ie, low speed scanning), a threshold is calculated and set by arithmetic processing based on the width count value.

The threshold update setting circuit 9Q for white (space) is
The operation of the black threshold update setting circuit 9P is changed to white (
It is the same as replacing it with a space).

FIG. 3 shows the above configuration as shown in the microcomputer 10.
FIG. 2 is a circuit diagram of an example formed using 0. When a power switch 104 connected to a DC power source 111 is turned on, current is passed to the light emitting element 101 via the microcomputer 100, and it emits visible light or the like. This light emitting element 101
When the light emitted by the barcode display surface 6 is scanned,
When the light receiving element 102 receives the reflected light from the barcode display surface 6, converts the light into an electrical signal, and inputs it to the microcomputer 100 via the A/D converter, the microcomputer 100 reads and decodes the barcode. , drives the transistor 113 and outputs an output to the buzzer 105 to indicate whether the data is good or bad, and if it is "good", the data is stored. Also, when the transfer key 106 for remote control transmission is pressed,
The microcomputer 100 takes out the data, converts the data into a remote control transmission format, and drives the transistor 115 to turn on the light emitting element 1 such as an infrared light emitting diode.
The remote control signals are transmitted sequentially from 07 onwards. Note that 108, 109, 110, 112, and 114 in FIG. 3 are resistors, and 116 is a coil.

When the power switch 104 is turned on and the barcode display surface 6 is scanned with the light emitted from the barcode reading circuit IA, the reflected light from the barcode display surface 6 is converted into an electrical signal and the barcode reading begins. .

For example, in FIG. 2(A), inside the scanning start mark 8
Start scanning from mark 8A to the right side, and at the same time start counting the width.
When it enters the black bar section, a falling signal 22 shown in Fig. 2 (B) is generated, and the white (space) width count value that was counted by the width counter circuit IB until then is stored in the width register. The width is newly counted from zero. Furthermore, when scanning continues as it is and exits the black (bar) area, the rising signal 2
3 is generated, this black bar) width count value is stored in the width register, and counting of the width of the starting margin 7F is newly started from zero. Also, a falling signal 22 which is the start of black data
The space register value, which is the immediately preceding data, and the width register value storing the black width value are compared in the barcode start margin detection circuit 9J, and here, the space register value is 8 times the black width value. , it is not considered the beginning of a barcode and this data is ignored. As scanning continues, when it passes through the start margin 7F and enters the first black (bar) part of the barcode, a falling signal 2 is generated.
After the width count value of the start margin 7F is stored in the width register, it is further transferred to the white (space) width register, and counting of the width of the black 7A is newly started. When the scanning continues further and the black portion is exited, a rising signal 21 is generated and the oven width count value is stored in the width register. Additionally, counting of the width of the white (space) 7B on the right is newly started from zero. The white space (white space) width register value storing the width value of the start margin 7F and the kiln width register value storing the black 7A width value are compared in the barcode start margin detection circuit 9J, and the start margin 7F is Since it is more than 8 times the width of black 7A, it recognizes the beginning of the barcode.

Furthermore, the scanning speed is checked by the scanning speed detection circuit 9H, and based on the width value of black 7A stored in the width register during low speed scanning (approximately 50 c+m/sec or less), the threshold setting circuit 9J for black (bar) is performed. Therefore, black 7A calculates and sets the threshold for determining the O/1 of black (bar) 7P next to white (space) 7B on the right as "Dara da O".Continue scanning and set white 7B. out black 7
When entering P, it produces a falling signal and the white 7B width count is stored in the width register. Also, the width counting circuit IB newly starts counting the width of black 7P from zero. Next, based on the width value of white 7B stored in the width register, make a white space)
In the threshold setting circuit 9M, white 7B is data “0”.
- Calculate and set the threshold to determine O/1 of White 7Q next to Black 7P on the right. However,
When setting each of the thresholds, the scanning speed detection circuit 9
Check the speed with H, and if the speed is high (for example, about 50c)
+a / sec or more), based on the width register value, extracts a plurality of pre-stored data from the threshold memory 9R during high-speed scanning according to the width register value,
Let it be the black or white threshold.

In other words, during high-speed scanning, R is immediately calculated without complicated calculation processing.
Since data is retrieved from OM and set, processing time is extremely short and high-speed reading is possible.

Next, check the barcode end margin detection circuit 9 to confirm that the stop margin 7G has not been reached, and continue scanning.
When it exits and enters white 7Q, a rising signal is generated and black 7P
The width count value is stored in the width register. Also, the width counting circuit IB starts counting the width of white 7Q from zero. Since the signal that entered first was a rising signal in the black/white data detection circuit IE, the data immediately before entering white 7Q is detected as black data.

Furthermore, the data (0/1) judgment/registration circuit compares the previously detected black data 7P with the threshold already set by the black (bar) threshold setting circuit 9, and the data (0/1) is determined as 0/1.
Make 1 judgment. Since this black data 7P has a narrow width as shown in FIG. 2(A), it is determined and registered as 10''.

Next, based on the black data 7P, a new threshold is set in the threshold update setting circuit 9P for black bars, and the process returns to barcode reading, and the above operation is repeated until the stop margin 7G is detected. However, the threshold I/threshold value for 0/1 determination is one that is updated and set sequentially, and the one set by the threshold setting circuits 9L and 9M is not used.

In addition, since the data that comes in after black 7P is white 7Q, the data O/1 judgment is made by comparing the white data 7Q with the threshold setting circuit 9L for white space), and for updating the new threshold, white is used. (space) threshold update setting circuit 9Q is used. In this way, the thresholds for black and white are set separately, and O/1
Since it is used for determination, the quality of read data is not influenced by variations in finish (printing, etc.) on the barcode display surface.

Also, a black/white threshold update setting circuit 9P.

The threshold setting operation of both circuits 9Q and 9Q during high-speed scanning is similar to that of the threshold setting circuits 9L and 9M described above.

As the barcode reading progresses and the stop margin 7G is detected, the barcode reading ends and the captured data is transferred to the barcode decoding section 2. From then on, the operations of each section are the same as in the conventional example and will be omitted. .

Furthermore, according to the configuration of this embodiment, since the margin detection circuit is divided into two parts, one for start and one for stop, and the detection method is changed, the barcode pattern shown in the conventional example in FIG.
Therefore, even if reading scanning is started by mistake, the white width value from the × mark 8N, which is the data immediately before the scanning start mark 8, will be 8 of black 8.
Since the scanning start mark 8 and the start margin 7F are not judged as barcode data, the start margin 7F is a black bar) 7A of 8.
Since there are more than twice as many barcodes, the start of the barcode can be correctly recognized and reading errors or malfunctions will not occur. The margin to the left of the scan start mark 8 (the margin with the cross mark 8N) displays many barcode patterns in magazines that publish TV programs, so there is actually little margin in this area. Moreover, since the barcode pattern including the scanning start mark is enclosed in a single frame to distinguish it from other patterns, there are no scanning errors.

As described above, according to this embodiment, there are dedicated threshold setting circuits for black and white, and the threshold setting circuits are set individually, and data O/1'! Since the I4 setting uses an individually set threshold for black or self-respect, it has become possible to eliminate reading errors and malfunctions caused by variations in barcode printing specifications.

In addition, the margin detection circuit is divided into one for the start margin and one for the stop margin (one circuit in the conventional example), and when detecting the start margin, the white data immediately before the input black data is compared with the black data. Therefore, even if the scanning start position deviates from the scanning start mark, the barcode pattern can be read correctly and there is no fear of malfunction.

In addition, even if a barcode is input by scanning the barcode display surface at high speed, a scanning speed detection circuit is set up to detect the speed, and if the speed exceeds a predetermined speed, multiple scanners for high speeds prepared in advance are used. Since the threshold corresponding to the speed is immediately extracted and set from the threshold of

As described above, this embodiment makes it possible to provide a highly practical and highly reliable barcode input type remote control transmitter.

Effects of the Invention As is clear from the description of the embodiments above, it is possible to reliably read barcodes from low to high scanning speeds, and there are dedicated Since the threshold is provided, it is possible to provide a highly reliable barcode reading device that is not affected by variations in barcode display printing, and its practicality is extremely excellent.

[Brief explanation of the drawing]

FIG. 1 is a circuit configuration block diagram of an embodiment of the present invention;
Figure 2 (A) is a typical barcode pattern diagram, Figure 2 (B) is a signal waveform diagram when the barcode is read, Figure 3 is a circuit diagram of the same example, and Figure 4. 5 is a block diagram of a circuit configuration of a conventional device, FIG. 5 is a bar code pattern diagram, FIG. 6 is an enlarged model diagram of the same bar code, and FIG. 7 is a display example of the bar code pattern. IA...Barcode reading circuit, IB...
・Width counting circuit, IE...Black/white data detection circuit, 6...Barcode display surface, 9L...
Threshold setting circuit for black (bar), 9M...
・Threshold setting circuit for white (space), 9P...
・・・・Threshold update setting circuit for (black bar), 9
Q...Threshold update setting circuit for white (space), 9N...Data (0/1) judgment/registration circuit, 9H...Scanning speed detection circuit, 9R...・
...Threshold memory during high-speed scanning. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1 Ichiichi Utsuri--■-----Ichiichi Kochu" Figure 2 Figure 3 Figure 4 [--□--Hibiki-j l Figure 6 Figure 7

Claims (1)

[Claims] a barcode reading means for converting a barcode display into an electrical signal; a counting means for counting the pulse width of the electrical signal;
a scanning speed detection means, and when the scanning speed is equal to or higher than a predetermined value;
A predetermined threshold setting value for black (bar) or white (space) is set according to the scanning speed, and when the scanning speed is below the predetermined value, a threshold setting means for black is set based on the output from the counting means. , white threshold setting means, respective threshold update setting means, black/white data detection means for detecting black or white based on changes in input signals, read black or white data and the black or white threshold. A barcode reading device comprising data determination means for individually comparing data with set values, determining data 0 or 1, and storing the data.