JPS63146186A - Bar code reader - Google Patents

Abstract

PURPOSE:To stabilize the output of an amplifier and to improve a read rate by allowing an automatic gain control circuit to control the amplification factor of an amplifier which amplifies an electric signal from a sensor which reads a bar code and converts it into an electric signal. CONSTITUTION:A sensor 1 consists of a light emission part and a light reception part and a light beam emitted by the light emission part is reflected by a part where a bar code is printed and inputted to the light reception part, but the input light varies in intensity in this case owing to a difference in reflection rate. The photodetection part converts the variation of the light into the variation of the electric signal and the converted electric signal is amplified by the amplifier 2. In this case, the automatic gain control circuit 7 controls the amplification factor of the amplifier so that the amplified signal has a prescribed amplitude. Consequently, a stable output is obtained and the read rate is increased even when the characteristics of the sensor and the printing method for the bar code have variance.

Description

[Detailed Description of the Invention] Industrial Application Field The present invention is capable of inputting information such as timer start and end times and reserved channels into devices such as video tape recorders using bar codes. The present invention relates to a barcode reading device.

BACKGROUND OF THE INVENTION In recent years, barcode reading devices have been widely used in consumer devices such as video tape recorders due to their ease of operation.

An example of the above-mentioned conventional barcode reading device will be described below with reference to the drawings.

FIG. 2 shows a block diagram of a conventional barcode reading device.

11 is an optical sensor for reading barcodes, 12 is an amplifier, and 13 is a digitizer that has a certain threshold and converts an analog signal into a digital (binary) signal. 1
4 is a barcode decoder, 16 is a memory for storing information of the decoded barcode, 16 is a memory 16
This is an output device for converting the information into a signal and outputting the signal.

The operation of the conventional barcode reading device configured as described above will be described below.

First, the sensor 11 consists of a light emitting part and a light receiving part, and the light rays emitted from the light emitting part are reflected by the part on which the bar code is printed and input to the light receiving part. In this case, the intensity of the input light changes due to the difference in reflectance. The light receiving section converts changes in the light into changes in electrical signals. The converted electrical signal is amplified by the next stage amplifier 12. The amplification degree of this amplifier 12 is constant. The analog signal amplified here is binarized into high level and low level by a digitizer 13 having a certain threshold value. This signal is converted into a binary number by a decoder 14. The converted barcode information is stored in memory 15. When it is desired to output barcode information, the information in the memory 15 is outputted by the output device 16 wirelessly or by wire to the device to be controlled.

Problems to be Solved by the Invention However, in the above configuration, the output variation of the sensor is large, so it is necessary to adjust the amplification degree depending on the sensor. The variation in sensor output is due to the light emission level of the light emitting element and the output of the light receiving element.

This is due to variations in the optical system (lenses, etc.) and is extremely large. Therefore, when the output increases, the amplifier saturates,
Correct waveforms cannot be obtained. Also, if the output becomes small, the digitizer will not be able to operate properly. Conventionally, the degree of amplification was adjusted according to the sensor, which was an obstacle to improving productivity. In addition, the output of the sensor depends on the reflectance of the barcode sheet, so there are also restrictions on the sheet.

In view of the above problems, the present invention provides a bar code reading device that automatically adjusts the amplification degree, eliminates the need for circuit adjustment, and improves the reading rate.

Means for Solving the Problems In order to solve the above problems, the barcode reading device of the present invention includes a sensor that reads a barcode and converts it into an electrical signal, and a sensor that amplifies the electrical signal from the sensor and converts it into an electrical signal. An amplifier whose amplification degree can be varied, an automatic gain control circuit which controls the amplification degree of the amplifier so that the amplitude of the signal amplified by the amplifier becomes a specified value, and an output analog signal of the amplifier is converted into a digital signal. A digitizer to
It is equipped with a barcode decoder that decodes the digital signal from the digitizer, a memory that stores the data decoded by the barcode decoder, and an output device that can output the data in the memory.

Effects The present invention achieves a barcode reading device with the above-described configuration, which can provide stable output and has a high reading rate even if there are variations in sensor characteristics and barcode printing methods on barcode sheets. obtain.

Embodiments Hereinafter, barcode reading devices according to embodiments of the present invention will be described with reference to the drawings.

FIG. 1 shows a block diagram of essential parts of a barcode reading device according to an embodiment of the present invention. In Figure 1,
1 is a sensor that optically reads barcodes, 2 is an amplifier that amplifies the output, and 3 is connected to the output side and has a certain threshold, and converts analog signals into digital (
This is a digitizer that converts the signal into a binary (binary) signal. 4 is a barcode decoder that follows the digitizer 3; 5 is a memory for storing barcode information decoded by the barcode decoder 4; and 6 is a memory 6.
This is an output device for converting the information into a signal and outputting the signal. 7
is an automatic gain control circuit that automatically controls the gain of the amplifier 2.

The operation of the barcode reading device of this embodiment configured as described above will be described below. As explained in FIG. 1, the sensor 1 consists of a light emitting part and a light receiving part, and the light rays emitted from the light emitting part are reflected by the part on which the bar code is printed and input to the light receiving part. In this case, the intensity of the input light changes due to the difference in reflectance. The light receiving section converts changes in the light into changes in electrical signals. The converted electrical signal is amplified by an amplifier 2. In this case, the amplification degree of the amplifier 2 is controlled by the automatic gain control circuit 7 so that the amplitude of the amplified signal becomes a specified value.

The amplified analog signal is binarized into a high level and a low level by a digitizer 3 having a fixed threshold value at the next stage. The signal output here is encoded based on the length of the time axis. This signal is converted to 2 by barcode decoder 4.
Convert to base number. The converted barcode information is stored in the memory 6.

Here, if it is desired to output the barcode information to a device such as a video tape recorder, the information in the memory 5 is converted into a signal and outputted to the output device 6.

As described above, in this embodiment, the amplification degree of the amplifier that amplifies the electrical signal from the sensor that reads the barcode and converts it into an electrical signal is controlled by the automatic gain control circuit, so the output of the amplifier is stabilized. As a result, even if there are variations in the barcode printing method on the barcode sheet or in the characteristics of the sensor, stable output can be obtained, productivity in the factory is high, and the reading rate can be significantly improved. It becomes possible.

Effects of the Invention As described above, the present invention provides an extremely easy-to-use bar that provides stable output even if there are variations in the characteristics of barcode sheets and sensors, has high productivity in factories, and has a high reading rate. This makes it possible to realize a code reading device.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of the main parts of a barcode reading device according to an embodiment of the present invention, and FIG. 2 is a block diagram of the main parts of a conventional barcode reading device. 1...Sensor, 2...Amplifier, 3.
... Digitizer, 4 ... Barcode decoder, 5 ... Memory, 6 ... Output device, 7 ... Automatic gain control circuit.

Claims (1)

[Claims] A sensor that reads barcodes and converts them into electrical signals,
An amplifier that amplifies the electrical signal from the sensor and can vary the amplification degree, and an automatic gain control circuit that controls the amplification degree of the amplifier so that the amplitude of the signal amplified by the amplifier becomes a specified value. , a digitizer that converts the output analog signal of the amplifier into a digital signal, a barcode decoder that decodes the digital signal from the digitizer, a memory that stores the data decoded by the barcode decoder, and a memory that stores the data decoded by the barcode decoder. A barcode reading device comprising an output device capable of outputting data.