JPH0390978A - Bar code reader - Google Patents

Abstract

PURPOSE:To lead reflected light received from a bar code label to a photoelectric transducer with a small attenuation quantity by providing the photoelectric transducer at the fringe of a dust-proof window glass to receive the beams scattered by the bar codes and to transduce these scattered beams into electric signals. CONSTITUTION:A photoelectric transducer 8 is provided at the periphery of a dust-proof window glass 9 set on the upper surface of a device box. The laser light produced by a laser oscillator 1 is deflected by a rotaty polyhedral mirror 4, and the optical path of the laser light is changed by a fixed plane mirror 6. Then the laser light scans the bar codes on a bar code label 7, and plural transducers 8 receive the scattered beams reflected by the bar codes and transduce them into electric signals. Thus the scattered beams reflected by the bar codes are directly received by the transducer 8. Then it is possible to reduce the attenuation quantity of the beams scattered by the bar codes and reaching the transducer 8.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention is characterized in that one character consists of a plurality of black and white vertical lines (bars).
The present invention relates to a barcode reading device that reads a barcode on a barcode label represented by .

(Prior Art) Barcodes are pasted or printed on products as price tags at POS.
ales) systems. This barcode is read by a barcode reading device as shown in FIG. 4 in the following manner. Laser light generated by the laser oscillator 1 is converged into a narrow beam by a concave lens 12 and a convex lens 13. ! ! [The laser beam that has become an ugly beam is sent to the barcode label 7 by the rotating polygon mirror 4.
Changed to scan the barcode above. This rotating polygon 5! 4 has a pyramidal shape, and is rotated at high speed in the direction of arrow X by a motor 5. Then, the optical path is changed by a fixed plane mirror 6, passes through a dustproof window glass 9, and illuminates the barcode label 7. The scattered light reflected by the barcode on the barcode label 7 passes through the opposite path to that described above. That is, the light enters the condenser lens 3 through the path of the fixed plane mirror 6 and the rotating polygon mirror 4, and is condensed by the condenser lens 3. Then, the optical path is further changed by the direction changing mirror 2, and the light is received by the photoelectric conversion element 8. The photoelectric conversion element 8 converts this scattered light into an electrical signal. A predetermined process is applied to this electrical signal to decode the barcode information.

In this way, in a barcode reading device using a laser beam, in order to increase the recognition rate of the barcode label 7, it is necessary to increase the amount of scattered reflected light received from the barcode label 7.
This can be achieved by increasing the SN ratio of the output of the photoelectric transducer. As a means of increasing the amount of light received, it is conceivable to increase the output power of the laser oscillator 1, which is the light source. However, increasing the output power of the laser oscillator 1 is not preferable from the viewpoints of cost, miniaturization, safety standards, etc. of the barcode reading device.

Therefore, it is necessary to improve the efficiency of the optical system of the barcode reading device. In order to improve the efficiency of the optical system of the barcode reading device, it is necessary to increase the amount of scattered reflected light from the barcode label 7 that is reflected by the rotating polygon mirror 4 and the fixed plane mirror 6. In order to do this, it is necessary to improve the diffraction efficiency of the rotating polygon mirror 4 and the fixed plane mirror 6, or to improve the diffraction efficiency of the rotating polygon mirror 4 and the fixed plane mirror 6.
This can be achieved by increasing the light-receiving area of the

Rotating polygon mirror 4 and fixed plane! The diffraction efficiency of i6 can also be improved by increasing the surface area of the rotating polygon mirror 4 and the fixed plane mirror 6. However, by increasing the light-receiving areas of the rotating polygon mirror 4 and the fixed plane mirror 6 rather than doing this, the amount of scattered reflected light received from the barcode label 7 can be relatively easily increased. The laser beam generated by the laser oscillator 1 is focused into a narrower beam by a lens system, and the laser beam deflected by the 6-rotation polygon mirror 4 is irradiated onto the rotating polygon mirror 4. The optical path of the laser beam is changed by the fixed plane mirror 6, and the beam is turned into a narrow beam. Scan the code label 7. The scattered reflected light from the barcode label 7 follows the same optical path as the light transmission optical path to the rotating polygon mirror 4, is focused by the condensing lens 3, and is then converted into an electrical signal by the photoelectric conversion element 8. In other words, a rotating polygon mirror 4 with a large light-receiving area and a fixed plane! ! In order to obtain the effect of 6, it is necessary to increase the size of the condensing lens 3 and the like related thereto, as necessary, which increases the size of the entire barcode reading device.

(Problem to be solved by the invention) As mentioned above, in the conventional barcode reading device,
Since the light transmission optical path of the laser beam from the laser oscillator to the barcode label and the light reception optical path of the reflected light from the barcode label to the photoelectric conversion element coincide in the main part, the light amount of the reflected light from the barcode label can be reduced. The attenuation is large. In this way, conventional barcode reading devices have nine problems that need to be solved.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a barcode reading device that can guide reflected light from a barcode label to a photoelectric conversion element with a small amount of attenuation. .

(Means for Solving the Problems) In order to achieve the above object, the barcode reading device of the present invention deflects laser light generated by a light source using a deflector, and uses the light modified by the deflector for dust-proofing purposes. The laser beam is guided to a barcode label through a window glass, the barcode on the barcode label is scanned with a laser beam, the scattered light scattered by the barcode is received by a photoelectric conversion element, and the photoelectric conversion element absorbs the scattered light. In a barcode reading device that converts light into an electrical signal and processes the electrical signal to read information on the barcode, the photoelectric conversion element is disposed at the periphery of the dustproof window glass.

In addition, in order to achieve the above object, the laser beam generated by the light source is deflected by a deflector, and the light changed by the deflector is guided to the barcode label through a dustproof window glass, and Scan the barcode with a laser beam,
receiving the scattered light scattered by the barcode with a photoelectric conversion element, converting the scattered light into an electrical signal with the photoelectric conversion element,
In the barcode reading device that processes the electrical signal and reads the information of the barcode, a condensing lens is incorporated in a part of the dustproof window glass, and the photoelectric conversion element passes through the condensing lens. The scattered light is received.

Furthermore, in order to achieve the above object, the laser light generated by the light source is deflected by a deflector, the light modified by the deflector is guided to the barcode label through a dustproof window glass, and the light is directed onto the barcode label. Scan the barcode with a laser beam,
receiving the scattered light scattered by the barcode with a photoelectric conversion element, converting the scattered light into an electrical signal with the photoelectric conversion element,
A barcode reading device that processes the electric signal to read information on the barcode, further comprising a lens that directly receives and converges the scattered light that has passed through the dustproof window glass, and the photoelectric conversion element is connected to the lens. directly receives the scattered light converged at

(Example) Next, an example of the present invention will be described in detail with reference to the drawings.

FIG. 1(a) is a cross-sectional view of a barcode reading device according to a first embodiment of the present invention, and FIG. 1(b) is a plan view of the embodiment. Note that the same reference numerals as in FIG. 4 indicate the same parts. As shown in FIG. 1(b), in the first embodiment, the photoelectric conversion element 8 is arranged around the dustproof window glass 9 on the top surface of the device box 10. As shown in FIG.

A laser beam generated by a laser oscillator 1 is deflected by a rotating polygon mirror 4, and its optical path is changed by a fixed plane mirror 6. Then, the barcode on the barcode label 7 is scanned. A plurality of photoelectric conversion elements 8 receive the scattered light reflected by the barcode and convert it into an electrical signal. In this way, the scattered light reflected by the barcode is directly received by the photoelectric conversion element 8. Therefore, the amount by which the light scattered by the barcode is attenuated before reaching the photoelectric conversion element 8 is The amount can be significantly reduced compared to the conventional example shown in FIG.

FIG. 2<a) is a cross-sectional view of a barcode reading device of a second embodiment, and FIG. 2(b) is a plan view of the second embodiment. The difference from the first embodiment is that a condensing lens is incorporated into the dustproof window glass to form the window glass 11, and one photoelectric conversion element 8 is provided on the bottom surface of the device box 10.

FIG. 3 is a cross-sectional view of a barcode reading device according to a third embodiment, and FIG. 3(b) is a plan view of the third embodiment. The difference from the first embodiment is that a photoelectric conversion element 8 is disposed on the open surface of the apparatus box 10 on the left side in the figure, and a condenser lens 3 is provided in front of this photoelectric conversion element 8.

(Effects of the Invention) As described above, in the barcode reading device of the present invention, since the photoelectric conversion element directly receives the scattered light from the barcode, the attenuation of the amount of scattered light can be significantly reduced. Therefore, if the barcode reading device of the present invention is used, there is no need for the rotating polygon mirror 4, fixed plane mirror 6, and condensing lens 3, which have large light-receiving areas, so the barcode reading device can be easily miniaturized and costs can be kept low. It will be done.

Furthermore, since the light-receiving optical path does not include the rotating polygon mirror 4, fixed plane mirror 6, etc., it is possible to use the rotating polygon mirror 4, fixed plane mirror 6, etc. that do not require reflectance accuracy.

[Brief explanation of drawings]

FIG. 1(a) is a cross-sectional view of the first embodiment of the present invention.
FIG. 2(b) is a plan view of the first embodiment, FIG. 2(a) is a cross-sectional view of the second embodiment of the present invention, and FIG. 2(b) is a plan view of the second embodiment. 3(a) is a cross-sectional view of a third embodiment of the present invention, FIG. 3(b) is a plan view of the third embodiment, and FIG. 4 is a diagram of a conventional barcode reading device. FIG. 3 is a diagram showing the configuration. 1... Laser oscillator, 2... Direction conversion mirror, 3...
Condensing lens, 4... Rotating polygon mirror, 5... Motor, 6
...Fixed plane mirror, 7...Barcode label, 8...
- Photoelectric conversion element, 9... Dustproof window glass, O... Equipment box,... Window glass, 2... Concave lens, 3... Convex lens.

Claims (3)

[Claims] (1) The laser light generated by the light source is deflected by a deflector, the light changed by the deflector is guided to the barcode label through the dustproof window glass, and the barcode on the barcode label is illuminated with the laser light. A bar that scans, receives scattered light scattered by the barcode with a photoelectric conversion element, converts the scattered light into an electrical signal with the photoelectric conversion element, processes the electrical signal, and reads information on the barcode. A barcode reading device, characterized in that the photoelectric conversion element is arranged around the periphery of the dustproof window glass. (2) The laser light generated by the light source is deflected by a deflector, the light changed by the deflector is guided to the barcode label through the dustproof window glass, and the barcode on the barcode label is illuminated with the laser light. A bar that scans, receives scattered light scattered by the barcode with a photoelectric conversion element, converts the scattered light into an electrical signal with the photoelectric conversion element, processes the electrical signal, and reads information on the barcode. A bar code reading device, wherein a condenser lens is incorporated in a part of the dustproof window glass, and the photoelectric conversion element receives the scattered light transmitted through the condenser lens. (3) Deflect the laser light generated by the light source with a deflector, guide the modified light with the deflector to the barcode label through the dustproof window glass, and write the barcode on the barcode label with the laser light. A bar that scans, receives scattered light scattered by the barcode with a photoelectric conversion element, converts the scattered light into an electrical signal with the photoelectric conversion element, processes the electrical signal, and reads information on the barcode. The code reading device includes a lens that directly receives and converges the scattered light that has passed through the dustproof window glass, and the photoelectric conversion element directly receives the scattered light that has been converged by the lens. barcode reader.