JP2720647B2 - Barcode detection device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bar code detecting device used in POS, physical distribution, production management and the like.

[0002]

2. Description of the Related Art A conventional bar code detecting device is composed of one He-Ne laser tube for emitting laser light and one set of spherical lenses for condensing the laser light and generating a laser beam. Scanning means for scanning the laser beam, one light receiving means for receiving reflected light from the bar code of the laser beam to be scanned and converting it into an electric signal, and processing the electric signal output from the light receiving means And a single signal processing means for recognizing the bar code.

FIG. 2 is a diagram showing a configuration of a conventional barcode detection device. Laser beam generator 1 composed of a He-Ne laser tube 11 and a three-element spherical lens group 12
3 emits a laser beam 4. The emitted laser beam 4 is reflected and guided by the reflection mirror group 14, passes through the central hole of the concave mirror 5 having a central hole, and is scanned by the polygon mirror 6. The laser beam 4 scans on the bar code 7, and the reflected light from the bar code 7 follows the same path as the emitted laser beam 4, is reflected by the polygon mirror 6, and reaches the concave mirror 5. Here, the reflected light is collected on the PIN photodiode 8 by the concave mirror 5. The PIN photodiode 8 converts a light receiving signal into an electric signal. The signal processing means 9 processes and decodes the electric signal to detect a bar code code. The detected result is sent to the communication means 10. The communication means 10 communicates the bar code detected based on the result sent from the signal processing means 9 to the host computer.

[0004]

Conventionally, most barcodes have a truncation (bar height) of 18 mm or more. However, barcode truncation has recently become smaller, and barcodes with a truncation of 11 mm have been standardized. I am trying to do. When the truncation of the barcode is reduced, there is a problem that the probability of the laser beam crossing the barcode while the barcode passes through the reading range of the barcode detection device is reduced, so that the barcode reading rate is reduced. In order to increase the probability that the laser beam crosses the bar code, it is necessary to increase the laser beam scanning speed (the number of times of scanning during a certain period of time) of the bar code detecting device. Due to processing speed limitations, 200
It was difficult to increase the scanning speed to 0 scans / second or more.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and has as its object to increase the scanning speed of a laser beam and increase the bar code reading rate.

[0006]

Means for Solving the Problems] barcode detection device of the present invention in order to achieve the above object, a plurality of laser light sources for emitting a laser beam, the condenser Then together the laser beam
Have focal points close to each other and at approximately the same distance from each other.
Comprising a plurality of focusing means for emitting a sea urchin laser beam, scanning means for scanning a laser beam, and a plurality of light receiving means for converting into an electric signal by receiving light reflected from the bar code of the laser beam scanning It is a thing.

[0007]

According to the above arrangement, by providing a plurality of laser beam generating sections and a plurality of sets of focusing means ,
A plurality of laser beams can be simultaneously scanned with respect to a bar code at a specific position, and the laser beam scanning speed of the bar code detection device can be drastically increased without increasing the response of the light receiving means. .

If the signal processing means comprises a plurality of signal processing means, the processing speed can be increased, and the scanning speed can be increased.

In the case where the bar code detecting device is composed of a plurality of laser beam generating units as described above and a plurality of signal processing units paired with the respective laser beam generating units, the scanning speed is reduced by the number of the signal processing units. I can give it in proportion.

[0010]

1 (a) and 1 (b) show an embodiment of a bar code detecting device according to the present invention. FIG. 1 (a) is a plan view showing the structure of the device, and FIG. ) Is a front view.

A laser beam generator 3 composed of a visible semiconductor laser 1a that emits laser light having a wavelength of 670 nm and a single-piece aspherical lens 2a having a focal length of 6.0 mm.
a emits a laser beam 4a. Laser beam 4
“a” passes through the central hole of the concave mirror 5 a having a central hole, and is scanned by the polygon mirror 6. The laser beam 4a scans over the bar code 7, and the reflected light from the bar code 7 follows the same path as the emitted laser beam 4a, is reflected by the polygon mirror 6, and reaches the concave mirror 5a. Here, the reflected light is focused on the PIN photodiode 8a by the concave mirror 5a. The PIN photodiode 8a converts a light receiving signal into an electric signal. A signal processing means 9a composed of a 16-bit one-chip CPU processes and decodes the electric signal to detect a bar code. The detected result is sent to the communication means 10 composed of an 8-bit one-chip CPU.

Similarly, a laser beam generating section 3b composed of a visible semiconductor laser 1b that emits a laser beam having a wavelength of 670 nm and an aspheric lens 2b having a focal length of 6.0 mm emits a laser beam 4b. The laser beam 4b passes through the central hole of the concave mirror 5b having a central hole, and is scanned by the polygon mirror 6. The laser beam 4b scans over the bar code 7, and the reflected light from the bar code 7 follows the same path as the emitted laser beam 4b, is reflected by the polygon mirror 6, and reaches the concave mirror 5b. Here, the reflected light is reflected by the concave mirror 5b.
The light is focused on the PIN photodiode 8b. The PIN photodiode 8b converts a light receiving signal into an electric signal.
Signal processing means 9 composed of a 16-bit one-chip CPU
b processes and decodes the electric signal to detect a bar code. The detected result is sent to the communication means 10 composed of an 8-bit one-chip CPU. The communication means 10 communicates the detected barcode code to the host computer based on the results sent from the signal processing means 9a and 9b.

As described above, the laser beam generator 13 is conventionally constituted by the He-Ne laser tube 11 and the three spherical lenses 12, but in the present invention, the visible semiconductor laser (wavelength: about 670 nm) 1a is used. , 1b and the single aspherical lens 2a, 2b, the laser beam generators 3a, 3b can be spatially constituted by one-fifth of the conventional example. Laser beam generators 3a and 3b can be provided. In addition, the laser beam generators 3a and 3b are one-tenth of conventional ones in terms of cost.

According to the bar code detecting apparatus of the present invention, the bar code reading rate with a scanning speed of 2000 scans / sec and a truncation of less than 18 mm is 90%.
However, the scanning speed can be increased to 4000 scans / sec, and the reading rate of a bar code having a truncation of 11 mm can be maintained at 90% or more.

[0015]

As is apparent from the above description, according to the bar code detecting apparatus of the present invention, the scanning speed of the laser beam for reading the bar code can be increased remarkably, and the bar code reading can be performed. As a result, the efficiency of barcode reading can be greatly improved.

[Brief description of the drawings]

FIG. 1A is a plan view showing an embodiment of a barcode detection device according to the present invention. FIG. 1B is a front view showing a barcode detection device according to an embodiment of the present invention.

FIG. 2 (a) is a plan view of a conventional barcode detection device. FIG. 2 (b) is a front view of a conventional barcode detection device.

[Explanation of symbols]

 1a, 1b Visible semiconductor laser (laser light source) 2a, 2b Aspheric lens (condensing means) 4a, 4b Laser beam 6 Polygon mirror (scanning means) 7 Barcode 8a, 8b PIN photodiode (light receiving means) 9a, 9b Signal Processing means

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Masahiro Dan 1006 Kazuma Kadoma, Osaka Prefecture Inside Matsushita Electric Industrial Co., Ltd. (56) References JP-A-2-83686 (JP, A) JP-A-2-297768 (JP, A) JP-A-2-178918 (JP, A) JP-A-1-133659 (JP, U)

Claims (4)

(57) [Claims] 1. A plurality of laser light sources for emitting a laser beam, in the vicinity to each other with the laser beam was focused and each other
A plurality of focusing means for emitting a laser beam so as to have a focal point at substantially the same distance, a scanning means for scanning the laser beam, and an electric signal for receiving reflected light from the bar code of the scanned laser beam. A bar code detection device comprising: a plurality of light receiving means for converting the light into a light. 2. The scanning means comprises a set of scanning means.
2. The barcode detection device according to 1. 3. An electric signal output from the light receiving means is processed.
Claims comprising a plurality of signal processing means for recognizing barcodes
Item 3. The barcode detection device according to item 1 or 2 . 4. The laser light source is between 600 nm and 700 nm.
Semiconductor laser that emits laser light of
The focusing means is an aspheric lens, and the light receiving means is
And the signal processing means is a CPU.
Item 3. The barcode detection device according to Item 3 .