JPH01147783A - information reading device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an information reading device such as a barcode reader that reads barcodes that are printed binary information.

[Conventional technology]

This type of device reads barcodes affixed or printed on products, and is used in factory production lines, shipping lines, and supermarket cash registers.

Generally, in barcode leagues, since thin bars are read by optical means, a laser light source is used because it is easy to obtain a focused beam. As for laser light sources, there is a shift from gas lasers to semiconductor lasers due to market demands for smaller devices and longer lifespans.

In recent years, with advances in semiconductor technology, semiconductor lasers have become more reliable and cheaper year by year. In addition, it has the advantage of being compact and capable of direct modulation, and its field of use is rapidly expanding.

Despite the outstanding advantages of semiconductor lasers, barcode readers have the disadvantage that the light beam is not visible to the naked eye, so it takes time and effort to install and adjust the posture of the device. The disadvantage is that there is a high risk of damage to the (eyes). Currently, all semiconductor laser manufacturing companies are developing lasers with visible output, and commercially available products have near-infrared output (center wavelength is 780 nm or more).

Conventionally, in order to solve the above-mentioned drawbacks, a method of visually displaying the position of the light beam of a semiconductor laser has been proposed. The conventional method will be explained.

FIG. 3 shows the scanner section of the barcode league that displays the position of the light beam of the semiconductor laser. However, the decoder section is omitted here. In Fig. 3, 1 is a semiconductor laser, 2 is a collimating lens that obtains parallel light from the output light of semiconductor laser 1, 3 is a rotating polygon mirror that deflects the parallel light, and 4 is a receiver that receives reflected light from the rotating polygon mirror 3. 5.7 is a red (visible light) LED; 6, 8.9 are condenser lenses; and 10 is a light receiver that receives reflected light from the barcode 4 via the condenser lens 9.

The operation of the system in the barcode league configured as described above will be explained next.

First, for basic barcode reading, a light beam emitted from a semiconductor laser 1 is converted into parallel light by a collimator lens 2, and the parallel light enters a rotating polygon mirror 3. By rotating the rotating polygon mirror 3 in the direction indicated by the arrow in the figure, the light emitted from the rotating polygon mirror 3 scans the barcode 4 in the direction indicated by the arrow.

In synchronization with this scanning, reflected light from the barcode 4 is converted into an electrical signal by a condenser lens 9 and a light receiver 10.

The scanning position is indicated by the spots C and D shown. For this purpose, the scanning end of the parallel light beam from the rotating polygon mirror 3 on the barcode 4 is illuminated by two sets of light emitting elements, namely red (visible light) LEDs 5 and 7 and condensing lenses 6 and 8, as shown in the figure. Spots C and D are formed.

[Problem that the invention seeks to solve]

While the force is 1, in the above configuration, the position,
It takes a lot of time to adjust the alignment of the beams of the three light sources located in different spaces, that is, the semiconductor laser 1 and the red LBDs 5g and 7. Moreover, when the barcode 4 moves up and down in the depth direction, the above three Because the positional relationship of the light beam is disturbed, it is necessary to re-adjust it each time the installation conditions change.In addition, since both ends of the scanning light beam are displayed, it is possible to visually determine the positional relationship between the scanning beam and the barcode, which cannot be seen visually. I had to guess.

Therefore, it is impossible to judge whether or not the scanning light beam is reliably scanning the barcode surface, which poses a practical problem in that it takes a great deal of time to adjust the alignment between the device and the barcode. Therefore, the purpose of the present invention is to solve the above-mentioned drawbacks,
It is an object of the present invention to provide an information reading device that can easily and reliably display the scanning area of a light beam of a semiconductor laser by using a minimum number of additional optical means.

[Means for solving problems]

In order to achieve such an object, the present invention provides a first light source, a means for collimating a light beam emitted from the first light source, a second light source that emits visible light, and a light beam emitted from the second light source. means for converting the visible light beam into a parallel light beam; means for polarizing both the respective beams from the first light source and the second light source to scan the scanning object; and means for reading the reflected light obtained from the scanning object. , the respective light beams of the first light source and the second light source are incident on the same reflective surface of the scanning means at a specified interval from predetermined opposite directions, and are emitted from the scanning means at a constant angle to each other. The first light beam is synthesized so that the two light beams overlap with a time difference.
The scanning line of the light beam of the light source is a pseudo visualization of the light beam of the second light source.

[Effect]

In the present invention, the light from the semiconductor laser and the visible L1 are arranged in different directions in predetermined postures.
The light beam from imD is incident on the same reflecting surface of a rotating polygon mirror at a prescribed interval, and both the light beams of the semiconductor laser and the visible LED are deflected as the rotating polygon mirror rotates. Since the scanning lines are displayed in a pseudo-superimposed manner by overlapping the light beams, it is possible to install the information reading device or adjust the attitude of the scanning light beam and the barcode in a short time.

〔Example〕

Embodiments of the present invention will be described in detail below based on the drawings.

Figure 2g1 shows the scanner section (decoder section is omitted) of a barcode league in one embodiment of the present invention, where 1 is a semiconductor laser, 2 is a collimating lens, 3 is a rotating polygon mirror, 4 is a barcode, Reference numeral 9 represents a condenser lens, and 10 represents a light receiver, which are the same as the conventional example shown in FIG. 3 up to this point. Furthermore, 11 is a red (visible light) LED, 12 is a collimating lens (G'), the light from the LED II is made into parallel light by the collimating lens 12, the parallel light is made incident on the rotating polygon mirror 3, and the collimating lens 2 The light is superimposed on the light from the bar code 4 and is emitted from the bar code 4.

The operation of the barcode league of this embodiment configured as described above will be explained below based on FIG. 2. Regarding the barcode reading operation, please refer to 1 of each part in Figure 3.
4 and 9.10, so the explanation thereof will be omitted here.

Here, as shown in FIG. 2, the semiconductor laser and the red LED II are arranged at opposite positions P and Q while maintaining an equiangular angle θ1 with respect to the scanning central axis O, and the respective light beams are directed to the collimating lens 2. and 12, the light becomes parallel light, and is incident on R and 8 points on the same reflective surface of the rotating polygon mirror 3. Here, the points 1L and 8 maintain an equiangular angle θ2 with respect to the rotation axis of the rotating polygon mirror 3, and the angle θ2 is 1/4 of the dividing angle of the rotating polygon mirror 3.

Thus, the scanning width of the light beam formed by the rotation of the rotating polygon mirror 3 is defined by the following equation (1).

ψ=2X360/n (1
1n is the number of surfaces of the rotating polygon mirror 3.

Therefore, the two parallel light beams emitted from points P and Q in the figure have a time difference of 2θ1 and have scanning widths ψ1 and ψ2 equal to ψ.

At this time, θ1 is set to a value l defined by the following equation (2).

ψ=91=ψ2=12(θ1+202)l
+21 As a result, the two light beams completely overlap on the surface of the barcode 4, although they have a time difference ψ3. Of course, the light beams do not overlap in the parts equivalent to the line segments R and S at both ends outside of the rotating polygon mirror 3 (7) R point and point 8, but this is because the scanning area E is smaller than the line segments R and S. If it is made large, it will not be a practical problem.

As described above, the present invention combines the light beam from the invisible semiconductor laser 1 and the light beam from the visible LgDll using the rotating polygon mirror 3 so that they overlap on the scanning object 4, thereby scanning. Since the light beam can be visually observed, there is an advantage that alignment adjustment between the device and the barcode can be made in a short time.

C. Effects of the Invention] As is clear from the above, according to the present invention, a semiconductor laser that emits an invisible light beam and an LED that emits a visible light beam are arranged at opposing positions with respect to a rotating polygon mirror. By making each light beam incident on the same reflective surface of a rotating polygon mirror and combining the scanning lines on the barcode so that they overlap with each other with a time difference, the scanning (reading) status of the barcode can be seen at a glance. Positioning adjustment with the cord can be done in a short time.

Moreover, since the two scanning lines are on the same optical path, the combining position will not change even if the barcode moves up and down in the depth direction.Furthermore, if the combining position is perfectly adjusted at the time of shipment, the light beam in the field will be This has the effect of significantly improving usability by eliminating the need for position adjustment and placing no burden on the user.

[Brief explanation of the drawing]

Fig. 1 is a configuration diagram showing the scanner section of a semiconductor laser barcode reader in an embodiment of the present invention. - Fig. 2 explains the operation of scanning line display of a semiconductor laser barcode reader in an embodiment of the present invention. FIG. 3 is a configuration diagram showing a scanner section in an example of a conventional semiconductor laser barcode reader. 1...Semiconductor laser, 2.12...Collimator lens, 3...Rotating polygon mirror, 4...Barcode, 5,7°11-$ color LgD, 6,8,9. ,, condensing Li2s, 1
゜... Light receiver. Non-explosion date/month yXX Sera I/l lower LAf2 1st
figure

Claims (1)

[Claims] 1) means for converting a first light source and a light beam emitted from the first light source into parallel light beams; a second light source that emits visible light and means for converting the visible light emitted from the second light source into parallel light beams; , an information reading device comprising: a scanning means for polarizing each light beam from the first light source and the second light source to scan a scanning object; and a means for reading reflected light obtained from the scanning object; An information reading device characterized in that the light source and the second light source are arranged so that their respective light beams are incident on the same reflective surface of the scanning means from directions at different predetermined angles at a constant interval.