JPH01253075A - Optical reader for bar code reader - Google Patents

Abstract

PURPOSE:To speedily, accurately and easily read a bar code label by equipping a polygon mirror with reflecting surfaces which slant at different angles to the direction of its rotary shaft core. CONSTITUTION:The polygon mirror 3 while rotating around its shaft core 3c at a high speed vibrates incident laser light 8 in an X-Y plane direction to make a main scan and this polygon mirror is in a nearly hexagonal prism shape and provided with 1st and 2nd reflecting surfaces on flank sides. First reflecting surfaces 3a1-3a3 are provided at a constant angle theta to the direction of the axial line l so as to project the laser light 8 on a 1st bar code label 7a stuck on a box 5. Then 2nd reflecting surfaces 3b1-3b2 are provided in parallel to the direction of the axial line l so as to project the laser light 8 on a 2nd bar code label 7b stuck on the box 5. Consequently, the laser light can be split into plural components to radiate the bar code label surfaces, and the bar code labels at plural positions can be read extremely easily at a high speed.

Description

[Detailed Description of the Invention] [Field of Industrial Application] This invention is an optical reading device for a barcode reader that reads information while scanning the surface of a barcode label on which various information is recorded with a laser beam using a polygon mirror. Let's look at things related to equipment.

[Conventional technology]

In recent years, barcode readers have come to be widely used in automated warehouses, distribution centers, factories, shops, etc. for automatically collecting product information, automatically sorting, giving work instructions, etc. This barcode reader usually irradiates a laser beam onto the surface of a barcode label affixed to a product, and reads the information recorded on the barcode label based on the light reflected from the label surface. It is configured.

By the way, when reading a barcode label using such a barcode reader, for example, the barcode label is scanned in a predetermined direction with respect to the surface of the barcode label, that is, in a direction that crosses each bar recorded on the barcode label. Various types of optical reading means (hereinafter referred to as optical reading devices) have been proposed and developed for this purpose. That is, as shown in FIG. 6, for example, this optical reading device includes a semiconductor laser (LD) 100 and a converging lens 102 that converges a laser beam 101 emitted from the semiconductor laser 100.

It is equipped with a polygon mirror 103 that vibrates in a certain direction, for example, in the horizontal direction α, and scans by irradiating the barcode label 106 of a box 105 packed with products moved and conveyed by a conveyor belt 104 with the laser light. There are known devices configured to do this.

By the way, in an optical reading device with such a configuration,
The laser beam 101 reflected on each reflective surface 103a of the polygon mirror 103 is irradiated onto the surface of the barcode label 106, making it possible to read barcodes at high speed. As shown in Figure 7, dust 10 happens to be in the area on the label surface that is irradiated with the laser beam.
If 7 etc. is attached, there is a risk that information may not be read correctly.

Therefore, as shown in FIG. 8, a galvanometer 108 is provided on the optical path of the laser beam 101 in addition to a polygon mirror 105 that performs scanning (main scanning) while rotating at high speed. There is also known a type configured to also perform scanning (sub-scanning) along the line.

In this type of optical reading device,
Even if a certain amount of dust or dust IO7 is attached to the surface of the barcode label 106, accurate information can be read, and the reliability is accordingly high, which is advantageous.

[Try to solve it! I topic]

However, in recent years there has been an increasing demand for rapid and detailed processing of products with barcode labels attached, and as a result, a large amount of unique information is required for each product. As a result, it is no longer sufficient to use only one barcode label as in the past, and products with multiple barcode labels attached have also been proposed.

Therefore, in order to read multiple barcode labels at high speed, for example, it would be possible to prepare as many reading means as there are barcode labels, but this would increase the cost and increase the size. There are drawbacks such as:

Therefore, the present invention provides an optical reading device for a barcode reader with a simple configuration that can quickly and accurately read information even when barcode labels are attached to multiple locations on one product. The purpose is to provide

[Means to solve the problem]

That is, the present invention provides an optical reading device for a barcode reader that reads information while scanning a barcode label surface on which various information is recorded with a laser beam using a polygon mirror. It is equipped with a plurality of reflective surfaces inclined at different angles relative to the reflector.

[Effect]

The optical reading device of the barcode reader of the present invention is provided with the reflective surface of the polygon mirror inclined at a plurality of different angles with respect to the direction of its rotation axis, thereby dividing the laser beam into a plurality of beams. The barcode label can be irradiated onto the surface of the code label, and by rotating the polygon mirror at high speed, barcode labels can be read at multiple locations extremely easily and at high speed.

〔Example〕

An embodiment of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 shows an optical reading device for a barcode reader according to the present invention, and this optical reading device includes a semiconductor laser 1, a converging lens 2, a polygon mirror 3, and a galvanometer 4.

In addition, the reference numeral 5 in the figure indicates that the specified product is packed and the first
．． The box 6 to which the second barcode labels 7a and 7b are attached is a conveyor belt that moves the box 5 in a predetermined direction.

The semiconductor laser 1 is designed to emit near-infrared light, that is, light with a wavelength of about 7800 nm (hereinafter referred to as laser light 8), and is the same as a conventional one.

The converging lens 2 is for converging the laser beam 8 emitted in a diffused state from the semiconductor laser 1, and is the same as the conventional one.

The polygon mirror 3 is for performing main scanning by vibrating the incident laser beam 8 in the X-Y plane direction while rotating at high speed around the zero core 3C. 1st. A device provided with a second reflective surface is used. The first reflective surface is for irradiating the laser beam 8 toward the first barcode label 7a attached to the box 5, and is provided so as to be inclined by a certain angle θ with respect to the axial direction. As shown in Figure 2, 6f[! Three mirrors provided on three adjacent side surfaces of the side surfaces ~3a1
．． It is composed of 3az, 3a:+. The second reflective surface is
It is for irradiating a laser beam 8 toward the second barcode label 7b attached to the box 5, and is provided parallel to the axial direction, and as shown in FIG. Three mirrors 3b+ provided on three adjacent side surfaces
,3b,.

It is composed of 3b3. Note that the polygon mirror of this invention is not particularly limited to that of this embodiment (for example, as shown in FIGS. 3 and 4, the axial direction of the rotation axis 9a of this polygon mirror 9 +Wul even if the first and second reflecting surfaces 9b and 9c having different inclination angles from each other are arranged alternately. It is not limited to a hexagonal columnar shape having a surface, and the inclination angle of the reflective surface is not limited to two types. For example, when reading a barcode label at 3w1, there are three types of inclination angles. It suffices if the configuration includes a reflective surface or the like.

The galvanometer 4 is for performing sub-scanning by vibrating the laser beam 8 in the direction of the core, in other words, it is for performing rusk scanning, and the same type as the conventional one is used. The mirror 4a is designed to reciprocate within a certain angle range at a sufficiently slow speed compared to the polygon mirror 3.

Therefore, according to this embodiment, the laser beam reflected on the first reflecting surface 3a1 of the polygon mirror 3 is reflected by the mirror 4a rotated by the galvanometer 4 and is sub-scanned while being sub-scanned. In figure 5,
The upper side of the first barcode label 7a is scanned. below,
Similarly, the laser beams reflected by the second 3az and third 3ax of the ff11 reflective surfaces scan the center and lower sides of the first barcode label 7a, respectively.

Next, the laser beam reflected by the first one 3b+ of the second reflecting surfaces of the polygon mirror 3 is reflected by the mirror 4a rotated by the galvanometer 4 and is sub-scanned, while being sub-scanned by the second reflecting surface 3b+ of the polygon mirror 3. Scan the upper side of the code label 7b. Similarly, the second one of the second reflective surfaces 3b2. The laser beam reflected by the third barcode label 3b scans the center and bottom sides of the second barcode label 7b, respectively.

〔effect〕

As explained above, according to the optical reading device for a barcode reader according to the present invention, the reflective surface of the polygon mirror is tilted at a plurality of different angles with respect to the direction of its rotation axis. can be divided into multiple parts and irradiated, in other words, it is possible to read multiple barcode labels at the same time, allowing more information to be read for each product and performing various detailed processing operations. Okawakami is extremely effective because it can be done.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an optical reading device for a barcode reader according to the present invention, FIG. 2 is a plan view showing a polygon mirror of the optical reading device according to the present invention, and FIG. 3 is a diagram showing the optical reading device according to the present invention. 4 is a plan view of the polygon mirror shown in FIG. 3, and FIG. 5 shows the scanning operation of the laser beam of the optical reading device according to the present invention for each barcode label. FIG. 6 is a configuration diagram showing an optical reading device of a conventional barcode reader. FIG. 7 is an explanatory diagram showing a laser beam scanning operation of the optical reading device shown in FIG. 6. FIG. 9 is a configuration diagram showing another conventional optical reading device, and FIG. 9 is an explanatory diagram showing the scanning operation in the optical reading device of FIG. 8. 7a, 7b...Barcode labels. 3.9・・・・・・・・・Polygon mirror. ８・・・・・・・・・・・・Laser light. 3a+t 3az, 3ai+3b++ 3bz. 3 t) 1, 9 b, 9 c...Reflecting surface. 4・・・・・・・・・・・・・・・ Galvanometer.

Claims (1)

[Scope of Claims] 1. In an optical reading device for a barcode reader that reads information while scanning a surface of a barcode label on which various information is recorded with a laser beam using a polygon mirror, the polygon mirror is arranged on a rotation axis. An optical reading device for a barcode reader characterized by comprising a plurality of reflecting surfaces inclined at different angles with respect to a core direction. 2. The optical reading device for a barcode reader according to claim 1, further comprising a mirror rotated by a galvanometer for sub-scanning by vibrating the laser beam in a direction different from the scanning direction of the polygon mirror.