JPH03250381A - Bar code detector - Google Patents

Abstract

PURPOSE:To read a bar code without contacting and to expand a using range as a bar code detector by using a laser beam as a light source to illuminate the bar code. CONSTITUTION:This detector is provided with laser beam sources 12 and 13 to illuminate the bar code 14, a light receiving lens 15 to image-form a reflected light from the bar code 14 and a one-dimensional image sensor 16 to light- receive an optical signal image-formed by the light receiving lens 15 and to convert it into an electric signal. Thus, since the bar code is illuminated with a laser beam with high energy density, illuminating intensity is high, the bar code 14 can be detected even in a condition in which the bar code detector is apart from the bar code 14 and a using range can be expanded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a barcode detection device used in POS, logistics, production management, and the like.

Conventional technology Conventionally, a barcode detection device whose light receiving section is composed of a one-dimensional image sensor uses a light source with a peak wavelength of 660 nm.
It consisted of an LED array in which LEDs were arranged in a bar shape.

FIG. 2 shows an example of a conventional barcode detection device. 1 is the case of the barcode detector, 2 is an LED array consisting of six LEDs arranged in a bar shape that generates visible light for reading the barcode detector, 3 is the barcode, and 4 is the light reflected on the barcode 3. 5 is a one-dimensional CCD image sensor that converts the image formed by the light-receiving lens 4 into an electrical signal. 6 is a barcode signal amplification device that amplifies the output signal of the one-dimensional CCD image sensor 5. Section 7 is a decoding section that detects and decodes the barcode signal output from the barcode signal amplification section 7.

The barcode 3 is illuminated by the LED array 2, and the reflected light enters the light-receiving lens 4 to form an image of the barcode 3 on the one-dimensional CCD image sensor 5. The black and white signal of the barcode 3 is converted into an electric signal by a one-dimensional CCD image sensor 5, amplified by a barcode signal amplifier 6, and decoded by a decoder 7.

Problems to be Solved by the Invention However, with conventional devices of this type, it is difficult to use the output of the LED array 2 efficiently, and the usage efficiency is as low as about 10%, and the irradiation intensity of the barcode irradiation surface is low. Since the aperture of the light-receiving lens 4 is weak, the amount of light reaching the one-dimensional image sensor 5 decreases when the aperture of the light-receiving lens 4 is narrowed down. 2, the range in which the light receiving lens can focus an image on the one-dimensional image sensor 5, that is, the reading depth is shallow (the minimum bar width is 0.19 mm).
The readable depth of barcodes is 11, 5III.
The readable depth of a barcode with an IL minimum bar width of 0.33 mm was approximately 34.2 mIm.

As shown in 2, the conventional barcode detection device whose light receiving section is composed of a one-dimensional image sensor can only be configured as a contact type barcode detection device that reads the barcode by touching the tip of the case of the barcode detection device to the barcode. There were restrictions on how it could be used.

The present invention solves these conventional problems, and aims to provide a barcode detection device that can be used in a wider range of applications.

Means for Solving the Problems In order to achieve the above object, the present invention provides a laser light source for illuminating a barcode, a light receiving lens for forming an image of reflected light from the barcode, and this light receiving lens. The sensor is equipped with a one-dimensional image sensor that receives an optical signal formed by an image and converts it into an electrical signal.

Effect of the Invention According to the present invention, since the barcode is illuminated with a laser beam having high energy density, the irradiation intensity is high and the barcode can be detected even when the barcode detection device is separated from the barcode. The range can be expanded.

Example FIG. 1 shows the configuration of an embodiment of the present invention.

11 is the case of the barcode detection device, and 12 is a semiconductor laser (Toshiba TOLDQ21) that generates visible light from 600 nm to 700 nm for reading the barcode detection device.
1), 13 is a condensing lens that condenses the light of the semiconductor laser 12, 14 is a bar code, and 15 is a light receiving lens that receives the light reflected on the bar code 14 and forms an image (focal length f-36 mTI, F number 73.5), 16 is a one-dimensional CCD image sensor (PvI N manufactured by Matsushita Electronics Co., Ltd.) that converts the image formed by the light receiving lens 15 into an electrical signal.
3644'), 17 is a barcode signal amplification unit that amplifies the output signal of the one-dimensional CCD image sensor 16, 18
is a decoding section that detects and decodes the barcode signal output from the barcode signal amplification section 17.

Next, the operation of the above embodiment will be explained. The laser beam emitted from the semiconductor laser 12 passes through the light receiving lens 13.
1m in the direction parallel to the barcode of barcode 14
The barcode 14 is illuminated with a convergence of m and condensed in a width of 110 mm in the direction perpendicular to the barcode. Barcode 14
The light reflected from the barcode is received by a light receiving lens 15 and an image of the barcode 14 is formed on a one-dimensional CCD image sensor 16. -dimensional CCD image sensor-16,
The black and white signal of the barcode 14 is converted into an electrical signal, which is amplified by the barcode signal amplifier 17 and decoded by the decoder 18.
decipher it.

Table 1 compares the specifications of the light receiving lens of the conventional barcode detection device and the barcode detection device of this embodiment.

Table 1 Conventional lens specifications Loss 1μ Focal length f 30. Omm 36
．． 0mIIF number FNo8.3 73
．． 5 path length L 130.0+n+n 225. Reading convergence at Omi focal position 1 65. Oim 11
0. oIll[lReading Depth Minimum Parvergence 0.45m1
S 11.5ii 101. On+m minimum bar radiation 0.33+u+ 3 34.2u++
301.0mm As shown in Table 1 above, if the light-receiving lens of this example is used, the reading depth of a barcode with a minimum bar radius of 0.19 300m1
You can take more than that.

However, on the other hand, the F-number of the light-receiving lens in this embodiment is approximately 88 times larger than that of the light-receiving lens of a conventional barcode detection device, and the amount of light reaching the dimensional image sensor is inversely proportional to the square of the F-number. This is a decrease of approximately 1/78.

On the other hand, Table 2 compares the irradiation intensity of the laser beam on the barcode surface of the LED array that is the light source of the conventional barcode detection device and the laser beam of this embodiment. Compared to the irradiation intensity of the LED array, which is the light source of a conventional barcode detection device, the irradiation intensity of the laser beam, which is the light source of this embodiment, is about 88 times. As a result, the amount of light received by increasing the F number of the light receiving lens is
Since the ED light source can be supplemented by using a laser beam, a non-contact barcode detection device with a deep reading depth can be constructed.

Table 2 Irradiation intensity Conventional example-Example 660nn 670nm 6 pieces 1 piece 2, 4nIf 3. On+W(0,4mWX
61) Usage efficiency 10% 80% irradiation area
9751u111. on+m” (15 circles x 651
11m) (1, OrIJnXIIO-m) Irradiation intensity 0.246 u W/rM? 21.8u
W/M irradiation intensity ratio: 188 In the above embodiments, the laser beam used was 600 to 700 nm, but laser beams in other wavelength ranges may also be used as appropriate.

Effects of the Invention As described above, according to the present invention, since a laser beam is used as a light source to illuminate the barcode, barcodes can be read without contact, and the range of use as a barcode detection device is expanded. The number of peak wavelengths used is high, and its industrial value is extremely large.

[Brief explanation of drawings]

FIG. 1 is a schematic configuration diagram of a barcode detection device showing an embodiment of the present invention, and FIG. 2 is a schematic configuration diagram showing an example of a conventional barcode detection device. DESCRIPTION OF SYMBOLS 11... Case of barcode detection device, 12... Semiconductor laser 13... Condensing lens, 14... ノ)-
code, 15...light receiving lens, 16...-dimensional CC
D image sensor-17...barcode signal amplification section,
18...Decoding section.

Claims (1)

[Claims] A laser light source for illuminating the barcode, a light receiving lens for imaging the reflected light from the barcode, and a one-dimensional light receiving lens for receiving the optical signal imaged by the light receiving lens and converting it into an electrical signal. Barcode detection device equipped with an image sensor.