JPH06337951A - Bar code reader - Google Patents

Abstract

PURPOSE:To provide a bar code reader capable of continuously and accurately reading out plural bar codes in mutually different directions only by one beam light scanner. CONSTITUTION:The bar code reader is provided with a polygon mirror 24 to be rotated at a prescribed speed to receive laser beams from a semiconductor laser 26 and generate light scanning lines by laser beams extended in the prescribed direction, plural reflection mirrors 32a, 32b for dividing light scanning lines generated by polygon mirrors fixed at mutually different angles into plural groups and successively projecting respective divided scanning lines to mutually different directions, a condensor mirror 36 for converging reflected light obtained by reflecting plural divided light scanning lines successively projected in the mutually different directions by the mirrors 32a, 32b by a bar code on plural objects, and a light receiving element 38 for receiving the reflected light converged by the mirror 36.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bar code reading apparatus capable of emitting light beams in a plurality of directions and scanning a bar code on an object arranged in a plurality of directions to read the information contained in the bar code. Regarding

[0002]

2. Description of the Related Art A bar code reader of the type described above is already known, for example, from Japanese Patent Laid-Open No. 3-218587. In the conventional bar code reading device of the type described above disclosed in this publication, as shown in FIG. 7A, a first bar code reading window 10a is formed on the upper surface of the main body case 10. A second bar code reading window 10b is formed downward at a bent end portion of an upward extending column 12 that is bent substantially horizontally above the upper surface after extending upward from the upper surface.

One laser scanner 14 is housed in the main body case 10. The laser scanner 14 includes a polygon mirror 14a that rotates at a predetermined speed and a polygon mirror 14a, as shown in FIG. 7B. The laser tube 14b arranged so as to face the polygonal peripheral surface, and the laser beam 16 emitted from the laser tube 14b toward the peripheral surface of the rotating polygon mirror 14a and reflected by the peripheral surface are further reflected in a predetermined direction. Reflecting mirror 14c and reflecting mirror 14
and a prism 14d that splits the laser light 16 reflected by c into two.

A part of the laser beam 16a emitted from the prism 14d is further guided to the reflecting mirror 14e and emitted upward from the first bar code reading window 10a, and in the meantime, the laser beam 16a is emitted in a predetermined direction of the polygon mirror 14a. Scanning is performed in a predetermined direction according to the rotation. The remaining laser beam 16b emitted from the prism 14d is guided to the second bar code reading window 10b by a plurality of mirrors 18 provided inside the upward extending column 12, as shown in FIG. 7A. , Second
The light is emitted downward from the barcode reading window 10b, and during this period, the polygon mirror 14a is scanned in a predetermined direction as the polygon mirror 14a rotates in a predetermined direction.

In the conventional bar code reading apparatus having such a structure, the object having the bar code on the upper surface or the lower surface is the first bar code reading window 10a on the upper surface of the main body case 10 and the upward extending column 12. If it is inserted between the bent bar and the second bar code reading window 10b, the bar code on the upper surface or the lower surface of the object will be the laser beam 16b or the first bar from the second bar code reading window 10b. Scanning is performed by the laser beam 16a from the code reading window 10a. The reflected light from the bar code follows the same optical path as the laser beam 16a or 16b scanning the bar code, returns to the laser scanner 14, and is provided with a reflected light condensing optical system (not shown) provided in the vicinity of the laser tube 14b. The information contained in the barcode is read.

[0006]

In the conventional bar code reading apparatus constructed as described above, the scanning lines are irradiated to the same object from two directions, and one scanning line scans the bar code. By doing so, the barcode information is read, but there is a problem in that the barcodes attached to the objects existing in multiple directions cannot be read.

The reason is that in the conventional bar code reading apparatus constructed as described above, two laser beams 16a and 16b, which are simultaneously separated from one laser beam 16, are used to make barcodes in mutually different directions. To scan the code,
When each of the two laser beams 16a and 16b simultaneously scans two bar codes, the reflected light from the two bar codes is mixed in the prism 14d, and both of the two bar codes can be read. Because there is no.

Further, even when only one of the two laser beams 16a and 16b scans one bar code, the remaining one laser beam is, for example, the first bar on the upper surface of the main body case 10. Code reading window 10a and upward extending pillar 1
Since the reflected light is generated from the surface of the above-mentioned object, which is inserted between the second barcode reading window 10b and the second barcode reading window 10b, on which the barcode is not provided, the reflected light from one barcode is generated. The reflected light is affected by the reflected light from the surface of the object where the barcode is not provided by the prism 14d, and the reading accuracy of the barcode inevitably decreases.

The present invention has been made under the above circumstances, and an object of the present invention is to accurately scan a plurality of bar codes in a plurality of mutually different directions in succession even though there is only one beam optical scanner. It is to provide a bar code reading device capable of reading a bar code.

[0010]

In order to solve the above-mentioned object, a bar code reader according to the present invention comprises: a beam light source for generating a beam of light; a beam light source for rotating at a predetermined speed,
A rotating mirror that receives a light beam from a beam light source and generates a light scanning line by a light beam that extends in a predetermined direction; a plurality of light scanning lines generated by the rotation mirror that are attached at mutually different angles A plurality of reflective mirrors that are continuously divided and sequentially emit in different directions; and a plurality of divided optical scanning lines that are sequentially emitted in different directions by a plurality of reflective mirrors are barcodes on multiple objects. It is characterized by comprising: a reflected light condensing optical system for condensing the reflected light reflected; and a light receiving element for receiving the reflected light condensed by the reflected light condensing optical system.

[0011]

The rotating mirror that rotates at a predetermined speed receives the light beam from the beam light source and generates an optical scanning line extending in a predetermined direction. The optical scanning line generated by the rotating mirror is continuously divided into a plurality of parts by a plurality of reflecting mirrors attached at different angles, and the plurality of divided optical scanning lines are sequentially emitted in mutually different directions. To be done. The reflected light obtained by the plurality of divided light scanning lines being reflected by the bar codes on the plurality of objects is condensed by the reflected light condensing optical system and received by the light receiving element.

Here, since one optical scanning line generated by the rotating mirror is continuously (that is, with a time difference) divided into a plurality of divided light scanning lines by a plurality of reflecting mirrors, a plurality of divided light beams are obtained. Reflected light generated by sequentially irradiating barcodes on a plurality of objects in which scanning lines are present in mutually different directions is also received by the light receiving element via the reflected light condensing optical system with a time difference. As a result, the reflected lights from the barcodes on the objects existing in mutually different directions are not mixed, and the barcodes on the objects can be accurately and continuously read from the barcodes. Can read code information.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Various embodiments of the present invention will be described in detail below with reference to FIGS. [First Embodiment] FIG. 1 schematically shows the entire structure of a first embodiment of the bar code reading apparatus of the present invention, and FIG. 2 (A) shows the bar code reading apparatus of FIG. 2 discloses a static mechanical structure excluding the electrical structure, and FIG. 2B shows an enlarged optical structure of the barcode reading apparatus of FIG.

As shown in FIG. 1, in the main body case 20,
A polygon mirror 24 is arranged which is rotated clockwise by a motor 22 at a predetermined speed. A semiconductor laser 26 is arranged at a predetermined position in the vicinity of the polygon mirror 24. In this embodiment, the semiconductor laser 26 is driven by a laser drive 27 to emit a visible laser beam having a wavelength of about 670 nm, for example.
The light is emitted toward the peripheral surface composed of a plurality of mirrors.

The laser beam emitted from the semiconductor laser 26 is the semiconductor laser 26 as indicated by the chain line.
And the polygon mirror 24 are arranged between the polygon mirror 24 and the polygon mirror 24 to reach the peripheral surface of the polygon mirror 24, and the peripheral surface of the rotating polygon mirror 24 causes the opening angle A to fall within a predetermined range. With a polygon mirror 24 almost horizontally
Optical scanning lines are generated which are scanned in the rotational direction of.

A pair of reflecting mirrors 32a and 32b are further arranged in the main body case 20 within the range of the optical scanning line having the opening angle A by the laser beam. The pair of reflecting mirrors 32a and 32b are combined in a V shape with their reflecting surfaces facing outward, and are directed to the polygon mirror 24 with their apexes located at substantially the center of the optical scanning line.

Such a pair of reflecting mirrors 32a, 32
b continuously divides the optical scanning line into two, and sequentially reflects the two divided optical scanning lines (hereinafter referred to as divided optical scanning lines) in mutually different directions.

As shown in FIG. 1 and FIG. 2A, the main body case 20 is composed of a pair of reflecting mirrors 32a and 32b.
A pair of bar code reading windows 20a, 20b for irradiating two divided light scanning lines toward the outside of the main body case 20.
have. A pair of bar code reading windows 20a, 2
Each width of 0b is slightly narrower than the scanning range of the corresponding divided light scanning line, and the optical sensor 34a or 34b is arranged at the edge of the corresponding divided light scanning line on the scanning start end side.

As shown in FIGS. 1 and 2B, a condenser mirror 36 is arranged between the polygon mirror 24 and the diaphragm 30, and the semiconductor laser 26 is provided at the center of the condenser mirror 36. An opening 36a for transmitting the laser beam directed to the polygon mirror 24 is formed.

The condensing mirror 36 has a pair of bar code reading windows in which the above-mentioned two divided light scanning lines irradiated toward the outside from the pair of bar code reading windows 20a and 20b of the main body case 20 are reflected by an object. The reflected light returning to the polygon mirror 24 via 20a, 20b and the pair of reflecting mirrors 32a, 32b is condensed to form a condensing mirror 36.
Light is received by the light receiving element 38 near. The light receiving element 3
Immediately in front of the light-receiving surface 8 is an optical filter 40 that transmits only light having the same wavelength as the laser beam emitted from the semiconductor laser 26.

As shown in FIG. 1, the light-receiving element 38 is an amplifier section 42 for amplifying an electric signal transmitted corresponding to the intensity of the light received by the light-receiving element 38 and a digital electric signal from the analog electric signal from the amplifier section 42. It is electrically connected to the data processing circuit unit 46 via the binarization circuit unit 44 for converting into a signal, and the two photosensors 34a and 34b are electrically connected to the data processing circuit unit 46 via the pulse circuit unit 48. Connected to each other.

In FIG. 2B, the divided optical scanning line reflected by the reflecting mirror 32b toward the corresponding bar code reading window 20b is located at the scanning start position and the bar code reading window 2 is displayed.
The bar code on the surface of the object which is received by the corresponding optical sensor 34b of 0b and is then irradiated to the outside through the corresponding bar code reading window 20b and is opposed to the bar code reading window 20b in the vicinity of the bar code reading window 20b. Scanning 50 is shown.

In the above-described first embodiment of the bar code reading apparatus, two mutually different bar code reading windows 20a and 20b arranged in the main body case 20 are provided.
A pair of barcode reading windows 20a, 20 on one object
From the amplifier section 42 in the case where the divided light scanning lines, in which two not-shown barcodes provided at positions opposite to b are successively and sequentially irradiated from the pair of barcode reading windows 20a and 20b, are scanned once. The output waveform is shown in Figure 3 (A).
3B, the output waveform from the binarization circuit unit 44 in the above case is shown in FIG.
In (C), the optical sensor 34 of the bar code reading window 20a corresponding to the first divided light scanning line in the above case.
The output waveform from a is shown, and FIG. 3D shows the output waveform from the optical sensor 34b of the bar code reading window 20b corresponding to the divided light scanning line in the latter half of the above case. 3E shows output waveforms from the data processing circuit unit 46 in the above case, and these output waveforms form a timing chart in FIG.

In FIGS. 3A and 3B, the first appearing waveform is the result of scanning the bar code by the first half divided optical scanning line irradiated from one bar code reading window 20a, and the next appearing waveform. Is the other barcode reading window 2
This is the result of scanning the barcode by the divided light scanning lines in the latter half irradiated from 0b.

In FIG. 3C, one waveform that appears before the first appearing waveform in FIGS. 3A and 3B shows that the optical sensor 34a near one bar code reading window 20a divides the first half. It shows that the scanning start of the optical scanning line is detected, and one waveform that appears between the first appearing waveform and the next appearing waveform in (A) and (B) of FIG. 3 in (D) of FIG. Indicates that the optical sensor 34b near the other barcode reading window 20b has detected the scanning start of the divided optical scanning lines in the latter half.

The output waveforms shown in FIGS. 3C and 3D from the photosensors 34a and 34b are, in the data processing circuit section 46, the first half divided light scanning lines irradiated from one bar code reading window 20a. To prevent the output of the result of scanning the bar code from being confused with the output of the result of scanning the bar code of the divided light scanning line in the latter half irradiated from the other bar code reading window 20b. Used.

As described above in detail, in this embodiment, a pair of reflecting mirrors 32a and 32b, in which one optical scanning line generated by the polygon mirror 24 is combined with each other, are divided into two divided optical scannings with a time difference. Since the two divided light scanning lines are divided into lines and are sequentially irradiated in two directions different from each other, they are located in two directions different from each other.
Two bar codes facing the two bar code reading windows 20a and 20b are provided on two different objects located near the one bar code reading windows 20a and 20b.
Sequential scanning can be performed with a time difference by one divided light scanning line, and the reflected light from the two bar codes is also received by the light receiving element 38 near the condenser mirror 36 with a time difference and is not mixed. Despite having only one beam light scanner, two bar codes can be read accurately in succession in two different directions.

Although the semiconductor laser 26 which emits a visible light laser beam having a wavelength of about 670 nm is used as the beam light source in the above-mentioned embodiment, a semiconductor laser which emits a laser beam having a different wavelength or, for example, H
Other types of lasers can be used, such as e-Ne lasers.

It goes without saying that the number of mirrors arranged on the peripheral surface of the polygon mirror 24, the rotation direction and the rotation frequency of the polygon mirror 24 can be changed as appropriate, and a plurality of mirrors on the peripheral surface of the polygon mirror 24 can be changed. By slightly changing the respective tilt angles in the vertical direction, one bar code is changed in the vertical position while the polygon mirror 24 is rotating, and the same divided optical scanning line is repeatedly scanned. You can also do it. [Second Embodiment] A static mechanical structure of a second embodiment of the barcode reading apparatus of the present invention is disclosed in FIG. 4 (A), and FIG. 4 (B) shows (A). ), The optical structure of the bar code reader of FIG.

The electrical structure of this embodiment is the same as the electrical structure of the first embodiment described above, and therefore is omitted, and the static mechanical structure and optical structure of this embodiment are also described above. The structure is basically the same as those of the first embodiment. Therefore, the same members as those of the first embodiment described above are designated by the same reference numerals, and detailed description thereof will be omitted.

The second embodiment differs from the above-mentioned first embodiment in that a pair of reflecting mirrors 32a 'and 32b' has an optical scanning line with an opening angle A by a laser beam from a polygon mirror 24 in a main body case 20. Within this range, the reflecting surface is directed outward and the vertices are separated, and the separated vertices are located in the approximate center of the optical scanning line.

Such a pair of reflection mirrors 32a ', 3
Reference numeral 2b 'continuously divides the optical scanning line into three, and makes the optical scanning lines divided into three (hereinafter, referred to as divided optical scanning lines) sequentially directed in mutually different directions.

As shown in FIG. 4A, the main body case 20 is a pair for irradiating the two divided optical scanning lines from the pair of reflection mirrors 32a 'and 32b' toward the outside of the main body case 20. In addition to the bar code reading windows 20a and 20b, another horizontal split light scanning line passing between the pair of reflection mirrors 32a 'and 32b' is directed to the outside of the main body case 20 to irradiate it. It has a bar code reading window 20c facing the direction.

The width of the other bar code reading window 20c is slightly narrower than the scanning range of the corresponding divided light scanning line, and the optical sensor 34c is arranged at the edge of the corresponding divided light scanning line on the scanning start end side. ing.

In this embodiment, one optical scanning line generated by the polygon mirror 24 is separated by a pair of reflecting mirrors 32a ', 32b', and a time difference of 3 is generated.
Since it is divided into one divided light scanning line and each of the three divided light scanning lines is sequentially irradiated in three different directions, as shown in FIG. Three bar code reading windows 20a, 20 located
Three bar code reading windows 20a, 20c, 20b on three different objects located near c, 20b.
The three bar codes 60a, 60c, 60b facing each other can be scanned in this order by the three divided light scanning lines with a time difference, and the reflected light from the three bar codes can also be scanned with a time difference. Since the light is not received by the light receiving element 38 in the vicinity and is not mixed, it is possible to accurately read three bar codes continuously in three mutually different directions even though only one beam light scanner is provided. Can be done.

Also in this embodiment, as in the case of the above-mentioned first embodiment, the optical sensor 34a in the vicinity of the one bar code reading window 20a detects the start of scanning of the first divided light scanning line, and the other one. The optical sensor 34c near one barcode reading window 20c detects the start of scanning of the second divided optical scanning line, and the optical sensor 34a near the other barcode reading window 20b scans the third divided optical scanning line. Detect the start.

The outputs from the optical sensors 34a, 34c, 34b are sent to the data processing circuit section 46 via the pulse circuit section 48 shown in FIG. 1, and in the data processing circuit section 46, one of the bar code reading windows is read. Output of the result of scanning the barcode by the first divided light scanning line irradiated from 20a and output of the result of scanning the barcode by the second divided light scanning line irradiated from the other barcode reading window 20c. Is used to prevent the third divided light scanning line emitted from the other barcode reading window 20b from being confused with the output resulting from scanning the barcode and processed. [Third Embodiment] FIG. 5 shows an enlarged optical structure of a third embodiment of the barcode reading apparatus of the present invention.

The electrical structure in this embodiment is omitted because it is the same as the electrical structure in the first embodiment described above, and the static mechanical structure and optical structure in this embodiment are the same as those described above. The structure is basically the same as those of the second embodiment. Therefore, the same members as those in the second embodiment described above are designated by the same reference numerals, and detailed description thereof will be omitted.

The third embodiment differs from the above-mentioned second embodiment in that a pair of reflecting mirrors 3 arranged in an inverted V shape.
That is, another reflecting mirror 32c inclined obliquely rearward is arranged between 2a 'and 32b'.

One optical scanning line generated by the polygon mirror 24 by the pair of reflecting mirrors 32a ', 32b' is divided into three optical scanning lines (hereinafter referred to as divided optical scanning lines). Among them, a pair of reflection mirrors 32a ', 32b'
The second split light scanning line passing between the two is reflected by the other reflecting mirror 32c so as to be directed upward.

A body case (not shown) is a pair of bars of the second embodiment for irradiating the two divided light scanning lines from the pair of reflection mirrors 32a 'and 32b' toward the outside of the body case 20. In addition to the pair of bar code reading windows similar to the code reading windows 20a and 20b, the remaining one reflected between the pair of reflecting mirrors 32a 'and 32b' and reflected upward by another reflecting mirror 32c. It has another upward bar code reading window (not shown) for irradiating one divided light scanning line to the outside of the main body case.

The width of the other upward bar code reading window is slightly narrower than the scanning range of the corresponding divided optical scanning line, and the optical sensor is arranged at the edge of the scanning start end side of the corresponding divided optical scanning line. ing.

In this embodiment, the same effect as in the case of the second embodiment described above can be obtained except that the scanning direction of the second divided light scanning line is upward. In FIG. 5, a pair of reflecting mirrors 32a 'and 32b separated from each other from one optical scanning line created by the polygon mirror 24.
The three divided light scanning lines divided with the time difference by the ‘′’ are three bar codes 70a, 70 on three objects different from each other in three different directions.
The state of scanning the c and 70b in this order with a time difference is also shown. [Fourth Embodiment] FIG. 6A shows an enlarged optical structure of a fourth embodiment of the barcode reading apparatus of the present invention.

The electrical structure in this embodiment is omitted because it is the same as the electrical structure of the first embodiment described above, and the static mechanical structure of this embodiment is the same as that of the first embodiment described above. It is basically the same as the static and mechanical structure. Therefore, the same members as those of the first embodiment described above are designated by the same reference numerals, and detailed description thereof will be omitted.

The fourth embodiment differs from the first embodiment described above in that the galvano mirror 80 is used instead of the polygon mirror 24.
Is using. As shown in FIG. 6B, the galvanometer mirror 80 is a plane mirror 80a that scans the laser light from the semiconductor laser 26 in a predetermined direction substantially horizontally within a predetermined opening angle A to generate a light scanning line. And a plane mirror 8
A pair of reflection mirrors 32 are arranged so as to surround the periphery of 0a.
Concave mirror 80b that collects the reflected light returning from a and 32b and causes the light receiving element 38 near the galvanometer mirror 80 to receive it.
And is rotated by a motor 82 in a predetermined direction, in the clockwise direction in the fourth embodiment, at a predetermined speed. The operation and effect in this embodiment are the same as those in the above-mentioned first embodiment.

[0046]

As described in detail above, in the bar code reading apparatus of the present invention, a plurality of bar codes can be continuously and accurately read in a plurality of mutually different directions, although only one beam optical scanner is provided. Can be read.

[Brief description of drawings]

FIG. 1 is a plan view schematically showing the overall structure of a first embodiment of a bar code reading device of the present invention.

2A is a perspective view showing a static and mechanical structure of the barcode reading apparatus of FIG. 1 from which an electrical structure is removed, and FIG. 2B is an optical diagram of the barcode reading apparatus of FIG. It is a perspective view which expands and shows a traditional structure.

3A is a diagram showing an output waveform from the amplifier unit in FIG. 1, FIG. 3B is a diagram showing an output waveform from the binarization circuit unit in FIG. 1, and FIG. FIG. 7D is a diagram showing an output waveform from the optical sensor having the above-mentioned electrical structure of the bar code reading window corresponding to the line, and (D) shows light of the above-mentioned electrical structure of the bar code reading window corresponding to the divided optical scanning line in the latter half. FIG. 3 is a diagram showing an output waveform from the sensor, and FIG. 3E is a diagram showing an output waveform from the data processing circuit section having the above-mentioned electrical structure in the above case.

FIG. 4A is a perspective view showing a static and mechanical structure of the bar code reading apparatus according to the second embodiment of the present invention, excluding the electrical structure, and FIG. 4B is the second embodiment. It is a perspective view which expands and shows an optical structure in an example.

FIG. 5 is an enlarged perspective view showing an optical structure in a third embodiment of the barcode reading apparatus of the present invention.

6A is an enlarged perspective view showing an optical structure of a fourth embodiment of the bar code reading device of the present invention, and FIG. 6B is a galvanometer mirror used in the fourth embodiment. It is a perspective view which expands and shows.

FIG. 7A shows a conventional bar code reading device which emits light beams in a plurality of directions and scans a bar code on an object arranged in a plurality of directions to read information contained in the bar code. It is a figure which shows the whole structure roughly, and (B) is a figure which shows the internal structure of the laser scanner in (A) schematically.

[Explanation of symbols]

20 ... Main body case, 20a, 20b, 20c ... Bar code reading window, 22 ... Motor, 24 ... Polygon mirror,
26 ... Semiconductor laser, 27 ... Laser drive, 28 ... Condensing lens, 30 ... Aperture, 32a, 32b, 32c, 32
a ', 32b' ... Reflective mirrors, 34a, 34b, 34c
... Optical sensor, 36 ... Condensing mirror, 36a ... Aperture, 38
... light receiving element, 40 ... optical filter, 42 ... amplifier section, 44
... Binarization circuit section, 46 ... Data processing circuit section, 48 ... Pulse circuit section, 50 ... Bar code, 60a, 60b, 60c
... bar code, 70a, 70b, 70c ... bar code,
80 ... Galvano mirror, 80a ... Plane mirror, 80b ... Concave mirror, 82 ... Motor.

Claims (2)

[Claims] 1. A beam light source for generating a beam light; a rotating mirror which rotates at a predetermined speed, receives a light beam from the beam light source, and generates an optical scanning line by the light beam extending in a predetermined direction; Mounted at different angles from each other,
A plurality of reflecting mirrors that sequentially divide the optical scanning line generated by the rotating mirror into a plurality of beams and sequentially emit the light beams in different directions; and a plurality of dividing beams that sequentially emit light beams in different directions by the plurality of reflecting mirrors. A reflected light condensing optical system that condenses the reflected light reflected by the bar code on the plurality of objects, and a light receiving element that receives the reflected light condensed by the reflected light condensing optical system; A bar code reading device characterized by being provided. 2. The bar code reading device includes a main body case that houses the beam light source, a rotating mirror, a reflection mirror, a reflected light condensing optical system, and a light receiving element, and the main body case includes a plurality of reflection mirrors. It includes a plurality of bar code reading windows for guiding a plurality of divided light scanning lines sequentially emitted in mutually different directions to the outside of the main body case, and corresponds to the vicinity of each of the plurality of bar code reading windows. The bar code reading device according to claim 1, further comprising an optical sensor that detects emission of the corresponding divided light scanning line from the bar code reading window to the outside.