KR900000858Y1 - Circuit for distinguishing goods using fixing scanner - Google Patents

Abstract

No content.

Description

Product detection circuit of stationary scanner

1 is a block diagram of the present invention.

2 is a detailed circuit diagram of FIG.

3 is a pattern diagram when barcode scanning.

* Explanation of symbols for main parts of the drawings

10: first detection unit 20: second detection unit

30: product judgment 40: counter

The present invention relates to the (SCANNER) product detection circuit of the stationary scanner, in particular, when the product passes on the scanner to determine the valid and invalid data in consideration of the time and the passing position, and after a predetermined time elapses the laser beam It is about a circuit which can be cut off.

In general, in order to read the information of the barcode displayed on the product, the laser beam is scanned in multiple directions to read the information written on the barcode.

A political scanner is a device that reads a bar code attached to a product by a laser beam as it passes over it, and must detect when the product came in and out.

In this case, when a stationary scanner is used, a problem may occur in that a product is recognized as two items or a product that is not a product as the product enters the product. Through this, there was a problem that the laser beam continues to be reflected even after a long time of reading the product.

Therefore, an object of the present invention is to provide a circuit that can determine that the entry of the product is valid and invalid in consideration of the time when the product is detected.

Still another object of the present invention is to provide a circuit that scans a laser beam upon entry of a product and blocks the laser beam after a predetermined time if there is no entry of another product.

Hereinafter, with reference to the drawings will be described in detail.

1 is a block diagram according to the present invention, the first and second detection unit (10.20) and is installed at the start and end position of the product entry in the stationary scanner to generate the first and second detection signals, respectively, when entering the product; And a product determination unit 30 which is driven when the first detection signal is generated and latches the count enable signal and a shutter open signal, and which is driven when the second detection signal is generated to generate a count reset signal and to clear the latched shutter open signal. And a counter unit which counts from the count enable signal generation time to the count reset signal generation time and generates a shutter close signal and a signal for ignoring the scanned product information when the product detection time exceeds a predetermined time ( 40).

Based on the above-described configuration will be described the present invention in detail.

The first detection unit 10 and the second detection unit 20, which are highlighted in the stationary scanner, are installed at a predetermined interval, and the first detection unit 10 detects the start of entry of the product and detects the second detection. The unit 20 detects the end of entry of the product, and when the product passes through the scanner, the first and second detection units 10.20 recognize the product with a predetermined time difference.

At this time, the product determination unit 30 for inputting the output of the first detection unit 10 and the second detection unit 20, the control signal for determining the valid data when the two outputs are generated at a predetermined time interval Occurs.

Then, the counter unit 40 is enabled by the control signal of the product determining unit 30 to count the entry time of the product.

At this time, the time for which the counter 40 is enabled becomes the generation place of the second detection signal from the first detection signal.

However, if the enable time exceeds a predetermined time, the counter unit 40 generates a shutterclose signal.

Accordingly, when the product detection signal is generated, the product determination unit 30 generates an enable signal to the counter unit 40 and generates a shutter open signal (a signal for scanning a laser beam). The unit 40 generates a shutter close signal to prevent scanning of the laser beam when the enable signal is continuously generated for a predetermined time or more.

FIG. 2 is a specific circuit diagram of FIG. 1 and includes a second sensing unit 10 including photodiode PD1, resistors Rl-R3 and transistor Ql, photodiode PD2, resistors R4-R6, and FIG. The second sensing unit 20 composed of the transistor Q2 and the end gates Gl-C3. Oagate (G4). Inverter (lGl). Capacitors (C1-C2). It consists of the goods determination part 30 comprised from the resistors R7-R8 and the latches F1-F2, and the counter part 40 comprised from the counter CNT and the oragate G5.

3 is a pattern diagram when bar code scanning, and (3A) is a pattern diagram when detecting a normal product. 3B is a case where the photodiode PD2 detects the photodiode PDl before the start of the entry of the single product. In this case, the product is invalidated, and 3C is applied to the photodiode PD1. The photodiode PD2 detects a product in the state of not detecting the entry of the product. In this case, the corresponding product is invalidated. In this case, the 3D detects the entry of the product from the photodiode PDl. Afterwards, when the product is detected twice in the photodiode PD2, the product is charged as a fee.

Based on the above-described configuration, the present invention will be described in detail with reference to the drawings and FIG.

When barcode scanning, the time to read the bar code of the product in the stationary scanner is very short, and the photodiodes PD1-PD2 are installed at regular intervals on the set to detect the entry and end of the entry of the product, respectively.

At this time, if the merchandise is not displayed in the stationary scanner, the photodiodes PD1 and PD2 receive light and are turned on, so that the anode ends of the photodiodes PD1 and PD2 are in a "high" state. Q1 and Q2) are turned on.

However, when the product enters, the photodiode PD1.PD2 cannot receive light, which causes the anode of the photodiode PDl.PD2 to be "low" and the transistor Q1.Q2 is turned off. It becomes a state.

First, a description will be given of a process in which entry and exit of a product are normally read.

When the goods enter the stationary scanner. First, the photodiode PDl detects this and the anode end is "low".

This causes the transistor Q1 to be turned off, thereby outputting a "high" signal to the selector terminal.

At this time, since the photodiode PD2 does not recognize the end of product entry, the transistor Q2 outputs a "low" signal. This causes the inverter I⊂U to output a "high" signal.

Therefore, the output of the AND gate Gl becomes "high" state. This signal is supplied to the clock of the latch Fl through the differential circuit C1.R7.

Therefore, the latch FD outputs a "high" signal, which is applied to the AND gate G3 and the AND gate G2 again.

The AND gate G3, which inputs the output of the latch Fl and the inverted output of the latch F2, outputs a “high” signal for enabling the centrifugal CNT at the start of product entry.

At this point, the counter CNT starts counting from the rising edge of the transistor Ql to the rising edge of the transistor Q2.

In addition, the output of the AND gate G3 enables the counter CNT and outputs a shutter open signal.

Afterwards, when the end of product entry is detected by the photodiode PD2 within a predetermined time Tl, the laser beam is blocked and the photodiode PD2 cannot receive light, which causes the anode end of the photodiode PD2. Becomes " low " and transistor Q2 is turned off.

At this time, the AND gate C2 inputs the collector of the transistor Q2 and the output of the latch F1. When both inputs are " high " relative, the AND gate C2 resets the counter CNT through the oragate G5. Let's do it.

In this case, the detected product information is determined to be valid.

In addition, the output of the AND (G2) is applied as a clock signal of the latch (F2), thereby outputting the "high" signal of the latch (F2) to the ora gate (G4) and differential circuits (C2, R8) Clear the latch (Fl).

The control unit then generates a clear signal with the latch F2.

At this time, the counter CNT starts counting at the time of commencement of entry through the AND gate G3. If the commodity entry end signal is not generated within T1 hours as shown in (3A) of FIG. 3, the counter CNT is connected to terminal 01. Generates a data ignore signal to ignore the product information.

The counter CNT2 then generates a shutter close signal for stopping the firing of the laser beam through the 02 terminal.

The above processes will be described with reference to FIG.

In this case, it is assumed that the product detection cycle from the start of the product entry to the end of the product entry is T1, and that a shutter close signal is generated when T1 <1 second is normal, and when 1 second <T1 <30 seconds, T1> 30 seconds. do.

When first detecting the entry of the product into the photodiode PDl, the transistor Q1 outputs a "high" signal as shown in (3A). As a result, the AND gate Gl outputs a "high" signal so that the latch Fl is It will latch the "high" signal.

At this time, the photodiode PD2 has not detected a product yet.

Therefore, the AND gate G3 outputs a "high" signal to generate a shutter open signal and at the same time enables the counter CNT.

At this time, if the photodiode PD2 detects the end of product entry within 1 second, the transistor Q2 outputs a "high" signal as shown in (3A), and the gate G2 normally latches F1 and the transistor. The collector output of (Q2) generates a "high" signal to clear the counter CNT.

In addition, the output of the AND gate G2 is applied as a clock signal of the latch F2, which causes the latch F2 to output a "high" signal, thereby clearing the latch Fl.

The latch Fl thus outputs a " low " signal to stop scanning of the laser beam.

However, when the photo diode PD2 fails to detect the product, the counter CNT is in the enabled state and continues to count the period by the clock applied.

At this time, if the period of T1 exceeds 1 second or more, the counter CNTl outputs a signal for disregarding the currently read commodity information to the controller through the 01 terminal.

Then, when the period of T1 exceeds 30 seconds, the shutter close signal is generated through terminal 02 and the counter CNT is reset to the oragate G5.

Secondly, when the photodiode PD2 detects a product before the photodiode PD1, the transistors Ql and Q2 may be output as shown by 3B.

In this case, since the output of the AND gate G1.G2 becomes "low" relative, the shutter remains closed and the laser beam is not scanned.

That is, the product detection signal is ignored.

In the case where the entry of the goods is detected by the photodiode PD2 in the state where the entry of the third photodiode PDl is not detected, the transistors Q1 and Q2 generate an output such as (3C).

In this case, since the AND gate G1 is maintained at the "low" state, the output of the latch F1 is also at the "low" state, thereby ignoring the output of the photodiode PD2 applied to the AND gate G2.

Thus, the shutter remains closed so that the laser beam is not scanned.

Fourth, when the outputs of the transistors Q1 and Q2 are equal to (3D), the start and end of product entry are sensed at about the same time. When the first photodiode PDl detects product entry, the latch F1 is detected. Outputs a " high " signal, thereby enabling the counter CNT via the AND gate G3 and simultaneously generating a shutter open signal.

Thus, the laser beam is scanned.

Since the photodiode PD2 detects the end of the product entry immediately afterwards, the AND gate G2 generates the reset signal of the counter CNT.

In addition, the latch F2 clears the latch F1 by outputting the "high" signal by the output of the AND gate G2.

Then, the output of the flip-flop Fl becomes "low" to close the shutter and stop scanning of the laser beam.

Then, the second signal sensed by the photodiode PD2 is ignored by the AND gate C2.

At this time, if the time when the scanner recognizes the barcode on the product in a pattern such as (3D) is quite short, the product information can be recognized even if the start and end of the product entry are detected at about the same time.

Therefore, in Fig. 3, patterns such as 3A and 3D are determined to be valid to scan the laser beam. Patterns such as 3B and 3C are invalid and are not scanned to scan the laser beam.

As described above, after detecting the start and end of the entry of the product in the stationary scanner, the corresponding detection time is counted to scan the laser beam only when the product detection state is valid, and the product detection time and the product entry interval When exceeding, the laser beam is blocked so that the operator can operate the scanner accurately and at the same time improve the safety of the laser beam.

Claims (1)

A product detection circuit of a stationary scanner that scans a laser beam by a shutter open signal and cuts off the laser beam by a shutter close signal, wherein the product is installed at a start and end position of a product entry in a stationary scanner to be first And first and second sensing units 10 and 20 for generating a second sensing signal, and are driven when the first sensing signal is generated to latch and output a count enable and shutter open signal, and are driven when the second sensing signal is generated. A product determination unit 30 for generating a count reset signal and clearing the latched shutter open signal; and counting from the time of the count enable signal generation to the time of the reset signal generation, and the product detection time exceeds a predetermined time. The counter unit 40 generates a signal for ignoring the scanned product information and a shutter close signal. A second detection signal in case of a normal item entry considered, and the detection time exceeds a predetermined time, or a second detection signal when the first result in products of the stationary scanner according to claim, wherein the operation to prevent the laser beam scan sensing circuit within.