JP2749973B2 - Barcode reader for engraved barcode - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a bar code reader for an engraved bar code.

[Conventional technology]

The engraved barcode is a recently developed technology and has a convexity of nλ ₀ (n is an appropriate integer) so as to correspond to data to be displayed on the iron plate 1 as shown in FIG. The bar code 3 formed by engraving a plurality of stripes 2 at predetermined intervals is read by the bar code reader 4, and has the advantage that stable reading is possible even if the bar code surface becomes dirty.

The bar code reader 4 is, as shown in FIG.
And the magnetoresistive sensor 6. The influence of the ridge 2 on the magnetic circuit of the magnet 5 is determined by the magnetoresistive sensor 6.
The width and arrangement interval of the ridges 2 are read based on a clock while scanning along the bar code 3 in the direction indicated by the arrow X.

[Problems to be solved by the invention]

However, when the arrangement interval of the ridges 2 is read based on the clock as described above, if the bar code reader 4 stops even momentarily in the middle of scanning, erroneous information about the width or the arrangement interval of the ridges 2 is obtained. Read, and the accuracy of the reading is lost.

Therefore, an object of the present invention is to provide a bar code reader that can maintain reading accuracy even when the bar code reader stops during scanning.

[Means for solving the problem]

These objects, bar a pair of magnetoresistive sensors are arranged in parallel at intervals in the scanning direction for lambda _0/2, it becomes so as to determine a stop in the middle scan by comparing the output of both magnetoresistive sensor Achieved by a code reader.

(Operation)

That is, in this bar code reader, but both the magnetoresistive sensor is to read the same ridges pattern with a deviation of lambda _0/2, a pulse corresponding to the convex strip from the two magnetoresistive sensors to the rising portion Λ ₀ /
You will have a gap corresponding to 2. This shift appears for a certain period of time as long as the bar code reader is scanning at a constant speed, but if the scanning is stopped halfway, the time for the shift to appear becomes longer. Therefore, the stop can be determined based on the time when the deviation appears, and erroneous reading due to the stop during scanning can be prevented.

〔Example〕

Hereinafter, an embodiment of the present invention will be described. In the following description, the same reference numerals are used for the same parts as those of the conventional example described above, and the overlapping description will be omitted as appropriate.

The invention bar code reader 10 by, as shown in FIG. 1, and are arranged in parallel with a pair of magnetoresistive sensor 11a, the interval of lambda _0/2 for scanning direction 11b. Therefore, as shown in FIG. 2, each output pulse of the two magnetoresistive sensors 11 (11a, 11b) has a λ ₀ /
It has a displacement L corresponding to 2. The deviation L appears for a certain period of time as long as the bar code reader 10 is scanning at a constant speed, that is, for a scanning time of a distance corresponding to the width of the deviation L, and appears when scanning is stopped halfway. The time gets longer. Therefore, the stop of scanning can be determined based on the length of time during which the deviation L appears, and erroneous reading due to the stop during scanning can be prevented.

However, such a stop determination is made only at a stop at a position where the deviation L appears, so that it is determined with a certain probability. However, it is determined based on the width or arrangement interval of the ridges 2 in a normal bar code. If there is, it is in the range where the effectiveness can be fully demonstrated.

〔The invention's effect〕

Bar code reader according to the present invention, or as came explained, since the determination as to stop in the middle of scanning by parallel pair of the magnetoresistive sensor at intervals of lambda _0/2, errors reading by stopping in the middle scan And reading can be performed with higher stability.

[Brief description of the drawings]

1 is a schematic configuration diagram of a bar code reader according to the present invention, FIG. 2 is an output pulse diagram of a magnetoresistive sensor, FIG. 3 is a schematic side view of a bar code, and FIG. It is a schematic structure figure of a code reader. 10 …… Bar code reader 11 …… Magnetic resistance sensor

Claims (1)

(57) [Claims] 1. A becomes a combination of a magnet and a magnetoresistive sensor, read the ridge is an integral multiple of ₀ width metal plate λ scans multiple stamped and formed by stamping bar code at a predetermined interval in the bar code reader used for the pair of magneto-resistive sensor for scanning direction is parallel with lambda _0/2 intervals, to determine a stop in the middle scan by comparing the output of both magnetoresistive sensor A bar code reader for an engraved bar code.