JPH03150685A - Stationary bar code scanner - Google Patents

Abstract

PURPOSE:To prevent double registration by restricting the reading range of a bar code symbol attached to an article when a basket is placed on the non- placing part of a sacker desk. CONSTITUTION:When the basket 18 is placed on the non-placing part of the sacker desk 13, the signal of the presence of the basket is introduced from a basket sensor 31 to a parameter selection control means 32. Here, the parame ter selection control means 32 selects a gain parameter for restriction and a pass-band frequency parameter stored beforehand in a memory on the basis of the basket presence signal so as to make the gain of an amplifier 24 small. Besides, the pass-band frequency of a filter 26 is restricted so as to restrict the reading range of the bar code symbol attached to a commodity in the basket 18. Thus, the double registration is surely prevented.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a stationary barcode scanner, which is widely used in POS, etc., and particularly relates to a stationary barcode scanner that has a function of restricting the reading area. Regarding.

[Prior Art] As shown in Fig. 6, this type of stationary barcode scanner scans a barcode symbol attached to a product with a laser beam, and uses reflected and diffused light obtained from the barcode symbol at that time. After the sensor 1 collects the light and converts it into a weak electrical signal, the sensor 1 and the preamplifier 2 are directly connected to amplify the weak electrical signal to an appropriate signal level without introducing noise. Thereafter, the output of the preamplifier 2 is amplified by a subsequent amplifier 3 to a signal level necessary for binarization and introduced into a binarization circuit 4. In this binarization circuit 4, the output of the amplifier 3 is converted into a binary digital signal "1" at a predetermined threshold value.
' and leads it to a decoder circuit (not shown), where the digital signal is decoded to decipher the barcode information.

A scanner with a built-in barcode reading function as described above has a configuration as shown in FIG. 7, for example. In addition to a keyboard 11 for inputting data, a display section 12 for displaying, for example, product-specific price data and total price data is arranged on the top surface of the vertical scanner body 10, and a laser beam 14 is placed on the surface near the soccer table 13. A reading window 15 is provided for reading barcode symbols attached to products etc. by illumination. 16 is a power switch. A cutting line 17 is attached to the soccer table 13.

By the way, when paying for the products placed in the basket 18, the basket 18 containing the products is usually placed on the A side of the soccer table 13, and the products are taken out one by one and passed through the reading window 15, so that the reading can be done. The laser beam from the window 15 scans the barcode symbol of the product, and the reflected light from this barcode symbol is detected by the sensor 1 shown in FIG. The digital signal obtained here is decoded by a decoder circuit.

[Problem to be solved by the invention] Therefore, when checking out a product, the basket 18 containing the product
It is common practice to scan by placing the basket 18 on the outside of the basket setting line 17 clearly marked on the soccer table 13, that is, on the A side. It may be placed on the B side of the soccer table 13. In this case, if the operator is still
The scanner itself reads the bar code symbol of the product in the basket 18 before scanning the product in the basket 18.

At this time, if the operator knows that the barcode is being read, the necessary measures such as cancellation or initialization will be taken and the problem will disappear; however, if the operator does not know at all, the customer or the operator An accident of double registration occurs because the person moves the basket 18 from the B side to the A side and scans the product again without taking appropriate measures.

Such incidents of double registration not only damage the store's credibility, but also cause trouble as they often occur especially when the checkout area is crowded, causing harm not only to those involved but also to subsequent customers. There are also problems that cause a lot of trouble.

The present invention has been made in view of the above circumstances, and it is possible to reliably restrict barcode reading when a basket is placed on the non-placement part of the soccer table, thereby preventing double registration and increasing customer satisfaction. The purpose of the present invention is to provide a stationary barcode scanner that prevents troubles with barcodes.

[Means for Solving the Problem] First, in order to solve the above problem, the corresponding invention of claim 1 emits light from a reading window of a scanner body provided so as to face the direction of the non-placement part on the soccer table. The barcode symbol is scanned with a laser beam, and the reflected light from the barcode symbol is received by a sensor and converted into an electrical signal.
In a stationary barcode scanner that obtains barcode information by amplifying this electrical signal with an amplifier and then converting it into a binary value with a binarization circuit, a bandpass filter is provided between at least the amplifier and the binarization circuit. and a cage sensing means for detecting the presence or absence of a cage on the non-resting part of the soccer table; gain parameters and passband frequency parameters that are set in advance depending on the presence or absence of a cage on the non-resting part; When a car presence signal is input from the car sensing means, a limiting gain parameter and a passband frequency parameter are selected and set in the amplifier and filter.
This configuration includes a lame/dark selection control means.

Next, the invention corresponding to claim 2 is a configuration in which a parameter setting means for setting a plurality of different gain parameters and bandpass frequency parameters manually or from a card is added to the invention corresponding to claim 1.

[Operation] Accordingly, the present invention takes the above measures, so that when a basket is placed on the non-placing part of the soccer table, a signal indicating that there is a basket is sent from the basket sensing means to the parameter selection control means. will be introduced in Here, the parameter selection control means selects a limiting gain parameter and a passband frequency parameter stored in the memory in advance based on the cage presence signal to reduce the gain of the amplifier and reduce the passband frequency of the filter. to limit the reading range of barcode symbols attached to products in the cart.

In addition, when the parameter selection control means receives a car-less signal from the car sensing means, it selects a large gain from the memory and sets it in the amplifier, while the filter has a passband that cuts out high-frequency noise. By setting the frequency and reading the original code symbol, double registration is reliably prevented even if the basket is placed on a non-placement part of the soccer table. be able to.

[Embodiments] Hereinafter, embodiments of the invention according to claim 1 will be described with reference to the drawings. FIG. 1 is a block diagram of a stationary barcode scanner according to the present invention.

First, the basic configuration of a scanner is a sensor 21 that detects reflected light reflected from a barcode symbol attached to an article by scanning with a laser beam through a reading window of the scanner body and converts it into an electrical signal, and a preamplifier 22. , an analog bandpass filter 23, and the output of this filter 23 as 2
An amplifier 24 amplifies the signal to a signal level necessary for conversion into a value, and converts it into a digital signal of "1°" and "0°" using the average value of the maximum value vH and minimum value V of the output of this amplifier 24 or a predetermined threshold value. The digital filter 26 includes a binarization circuit 25 and a digital filter 26.

The preamplifier 22 has a configuration in which gain parameters can be set externally, and the sensor 2
The weak electrical signal from 1 is amplified to the required signal level without any Zen sound being mixed in. The analog bandpass filter 23 has a configuration in which a band frequency parameter can be set from the outside, and has a function of limiting the band frequency and flattening the output, especially when a cage is placed on the non-mounting part.

This consists in limiting the signal by providing a certain range of reading resolution. Further, the digital filter 26 also has a configuration in which the band frequency parameter can be set from the outside in the same way as the analog band filter 23.
It has a function that measures the digital signal width obtained from the value conversion circuit 25 using a reference clock and does not output the signal when the width is below a certain value, above a certain value, or even outside a certain range, thereby eliminating voids included in the digital signal. Only normal digital signals are sent to a decoder circuit (not shown), where the digital signals output from the filter 26 are decoded. These filters 23 and 26 remove noise generated from the preamplifier 22.

There it is.

Furthermore, in addition to the basic configuration described above, crab sensing means 31 and parameter selection control means 3 are provided. This basket sensing means 31 outputs a signal indicating that a basket is present when a basket containing products is placed on the non-placing side of the → picker table, that is, on the B side. Pressure switches, touch switches, etc. may be placed on the non-1148 side of the stand at appropriate n intervals, or optical means or ultra-I sensing may be used.

On the other hand, the parameter selection control means 32 is composed of one microcomputer, a memory, an input/output capo, etc., and the memory contains gay parameters and passbands that differ between the non-mounting section with the cage and the case without the cage. Frequency parameters are stored, and when a car presence signal is inputted from the pug sensing means 31, a gain parameter smaller than that used when reading a normal barcode symbol is read out from the memory and set in the free amplifier 22, and at the same time the analog bandpass filter 2
3 and the digital filter 26 as well, parameters are set to limit the passband frequencies.

On the other hand, when a car-less signal is input from the car sensing means 31, a large gain parameter is similarly read out from the memory and set in the preamplifier 22, and the desired passband frequency parameter is also set in the analog band filter 23 and the digital filter 26. Read and set.

Next, the operation of the scanner configured as described above will be explained with reference to FIG. 2. First, based on the start command, the parameter selection control means 32 selects the car sensing means 31.
A sensing signal indicating the presence or absence of a car is captured and stored in the memory (step 51). After that, in step S2, the contents of the memory are read to determine whether or not there is a car. If it is determined that there is a car, the gain parameter stored in the memory is read out and the gain of the preamplifier 22 is reduced (step S3 ). The gain at this time is set, for example, to a value that allows the operator to read the barcode symbol of the product when the operator holds the product in his hand and approaches the reading window.

Further, the parameter selection control means 32 sets a passband frequency parameter for flattening the output in the analog bandpass filter 23 (step 34). After setting each parameter, the scanner starts a reading operation (step S5).

As a result, by setting the parameters as described above, waveforms as shown in FIG. 3 can be obtained from each component of the scanner. That is, when a barcode symbol is scanned using a laser beam along the scanning line shown in FIG. 2(a), a sensor output as shown in FIG. 2(b) is obtained from the sensor 21. Therefore, when the preamplifier 22 amplifies the sensor output based on a small set gain (for example, a gain of about 1), an output as shown in FIG. 2(c) is obtained. Therefore, this amplified output is passed through an analog bandpass filter 23 and an amplifier 24, and is binarized by a binarization circuit 25 based on a threshold value which is the average value of the maximum value 1ifI VH and the minimum value vL of the amplifier output. A digital signal like d) is obtained. By passing this digital signal through the digital filter 26, spot noise (see figure a) as shown in figure (e) is eliminated, and the barcode portion corresponding to figure (a) is also eliminated.
The barcode symbol no longer has any meaning and cannot be read as a barcode symbol.

Note that the digital filter 26 calculates the digital signal width shown in FIG. 3(d) by a total of 811 times using a reference clock, and does not output the signal when the width is less than a certain value.

Next, if it is determined in step S2 that there is no car, the large gain parameter stored in the memory is read out and set in the preamplifier 22, as described above (step S6). The gain at this time is set to a value that is sufficient to read even barcode symbols on products located far away from the reading window.

Furthermore, the parameter selection control means 32 sets a pass band frequency parameter for the analog band filter 23 that cuts high frequency noise almost simultaneously with setting the gain parameter (step S7). After setting each parameter as described above, a reading operation is started (step S5).

In this case, waveforms as shown in FIG. 4 are obtained from each component of the scanner. That is, when a barcode symbol is scanned along a scanning line using a laser beam as shown in FIG. 2(a), a sensor output as shown in FIG. 2(b) is obtained from the sensor 21. Therefore, in the preamplifier 22, the sensor output is amplified by increasing the gain.
) will give you an output like this. Therefore, this amplified output is passed through an analog bandpass filter 23 and an amplifier 24, and a binarization circuit 25 converts the amplifier output into a maximum value V and a minimum value V.
When binarized using a threshold value that is the average value of As shown, a digital signal similar to a barcode symbol can be obtained.

Next, an embodiment of the invention corresponding to claim 2 will be described with reference to FIG. In this figure, the same parts as in FIG. 1 are given the same reference numerals, and detailed explanation thereof will be omitted.

That is, the present invention adds parameter setting means to the configuration shown in FIG. 1 for setting a plurality of different gain parameters and one passband frequency parameter manually or from a card. This parameter setting means sets the passband frequency in two stages by manually inputting an on/off signal. The manual setting switch 41 gives a command for the automatic setting, the car presence/absence detection signal from the car sensing means 31 and the signal obtained from the manual setting switch 33 are converted into appropriate data and sent to the parameter selection control means 32. It is composed of a setting circuit 42 that provides a setting circuit 42, and an IC card, magnetic card, barcode card, etc. (hereinafter simply referred to as a card) 43 that inputs a parameter program of an arbitrary gain and passband frequency to this setting circuit 42. has been done.

Therefore, according to the configuration of this embodiment, by manually operating the manual setting switch 41 based on, for example, the surrounding environment, the parameters of the passband frequencies of the filters 23 and 26 can be set within a two-step range, for example. It can be changed with . In this case, the parameter selection control means 32 uses the car presence detection signal from the car sensing means 31 and the manual setting switch 4.
The preamplifier 22 and filters 23 and 26 read out the gain parameters and passband frequency parameters stored in memory in advance based on the on/off signals of
It is set to .

On the other hand, the card 43 can be used by preparing a plurality of cards 43 with different gains and passband frequencies programmed in advance, and selecting an appropriate card 43 according to various environmental conditions such as brightness, temperature, etc. Setting circuit 42
By storing the gain parameter and the passband frequency parameter in the memory of the parameter selection control means 32 through the gain parameter, the gain parameter and the passband frequency parameter can be freely varied.

Furthermore, it goes without saying that the present invention can be implemented with various modifications without departing from the spirit thereof. For example, when a large number of gain parameters are stored in the memory of the parameter selection control means 32, by providing a new gain correction means, the gain can be corrected stepwise or continuously depending on the surrounding brightness. . Specifically, this gain correction means includes an ambient light sensor 51 that detects ambient brightness, an amplifier 52 that amplifies the output of this ambient light sensor 51, and an A/D converter that converts the output of this amplifier 52 into a digital signal. The parameter selection M1 means 32 consists of a circuit 53, etc.
Then, the gain parameter is varied little by little in response to a digital signal corresponding to the brightness obtained from this A/D conversion circuit 53.

[Effects of the Invention] As explained above, the present invention provides the following various effects.

First, in claim 1, since the gain of the preamplifier and the passband frequency of the filter can be varied depending on the presence or absence of the basket on the non-placing part of the salator table, it is possible to vary the gain of the preamplifier and the passband frequency of the filter, especially when the basket is placed on the non-placing part. By setting the gain of the preamplifier to a small value and flattening the output of the filter, the reading range is limited, which makes it difficult to decipher the barcode attached to the product. 2
Multiple registrations can be prevented and troubles with customers can be prevented.

Next, in claim 2, it is possible to appropriately input and set the gain and passband frequency according to the surrounding environment, etc., to set appropriate gains and passband frequencies for the amplifier and filter, and similarly, it is possible to set the gain and passband frequency appropriately in accordance with the surrounding environment etc. It is possible to reliably prevent double registration even if a card is placed, and troubles with customers can be prevented.

[Brief explanation of the drawing]

1 to 4 are shown to explain an embodiment of the invention corresponding to claim 1, FIG. 1 is a block diagram of the stationary barcode scanner of the present invention, and FIG. FIG. 3 is a flowchart illustrating an example of the operation of the parameter control means shown in FIG.
The figure is a waveform diagram of each part of the scanner when no basket is placed on the soccer table, FIG. 5 is a block configuration diagram illustrating an embodiment of the invention corresponding to claim 2, and FIG. The figure is a block diagram of a conventional stationary barcode scanner.
Diagram N7 is a state diagram when the basket is placed on the non-grIt part of the soccer table. 13... Soccer table, 14... Laser beam, 15.
...reading window, 18...basket, 21...sensor, 22
...Preamplifier, 23...Analog band filter,
24...Amplifier, 25...Binarization circuit, 26...
Digital filter, 31... Car detection means, 32.
. . . Parameter selection control means, 41 . . . Manual setting switch, 42 . . . Setting circuit, 43 . . . Card.

Claims (2)

[Claims] (1) A barcode symbol is scanned with a laser beam emitted from the reading window of the scanner body, which is provided so as to face the non-placement area on the soccer table, and the reflected light from this barcode symbol is received by a sensor. After converting it into an electrical signal,
In a stationary barcode scanner that obtains barcode information by amplifying this electrical signal with an amplifier and then converting it into a binary value with a binarization circuit, a bandpass filter is provided between at least the amplifier and the binarization circuit. and a cage sensing means for detecting the presence or absence of a cage on the non-resting part of the soccer table; gain parameters and passband frequency parameters that are set in advance depending on the presence or absence of a cage on the non-resting part; parameter selection control means for selecting a limiting gain parameter and a passband frequency parameter and setting them in the amplifier and filter when a signal indicating that a cage is present is inputted from the cage sensing means; A stationary barcode scanner that limits the reading range of a barcode symbol attached to an item when a basket is placed thereon. (2) A barcode symbol is scanned with a laser beam emitted from the reading window of the scanner body, which is provided so as to face the non-placement area on the soccer table, and the reflected light from this barcode symbol is received by a sensor. After converting it into an electrical signal,
In a stationary barcode scanner that obtains barcode information by amplifying this electrical signal with an amplifier and then converting it into a binary value with a binarization circuit, a bandpass filter is provided between at least the amplifier and the binarization circuit. a basket sensing means for sensing the presence or absence of a basket on the non-resting part of the soccer table; a parameter setting means for setting a plurality of different gain and bandpass frequency parameters manually or from a card; and parameter selection control means for selecting a gain parameter and a pass band frequency parameter for restriction in the case of a car being set by the parameter setting means and setting the same in the amplifier and filter when a car presence signal is input. . A stationary barcode scanner, characterized in that when a basket is placed on a non-placement part of the soccer table, a reading range of a barcode symbol attached to the article is limited.