JPH07220016A - Code reader - Google Patents

Abstract

PURPOSE:To provide the code reader which is capable of accurately reading and is easy to adjust. CONSTITUTION:The reflection face of a polygon mirror 20J for light reception is provided at a prescribed angle alpha to that of a polygon mirror 20T1 for light throwing in the rotating direction, and the polygon mirror 20T1 for light throwing is so fixed that its center 20TC forms a prescribed angle B to a revolving shaft 20C. Irradiating light 10L from a light throwing device 10 strikes to the polygon mirror 20T1 for light throwing and is raster-scanned on a bar code 45 in the direction of an arrow 350 by the rotation of a polygon mirror 20 in the direction of an arrow 300. Reflected light 10R from the bar code 45 strikces to the reflection face of the rotating polygon mirror 20J for light reception while dispersing and is surely made incident on a light reception device 30 by the angular difference alpha between this polygon mirror and the polygon mirror 20T1 for light throwing. Consequently, the bar code is accurately read.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a code reading device, and more particularly, to reading accuracy and facilitating adjustment.

[0002]

2. Description of the Related Art In recent years, barcodes have been added to many products for the purpose of product management and the like, so that barcode reading devices are used in factories and distribution processes. In general, a bar code reading device refers to a device that illuminates (scans light) an original bar code attached to a product or the like and determines the type of the product or the like based on the reflected light.

There are various scanning methods of light in such a bar code reading apparatus, and the raster scanning method is widely used. The raster scan method is a method in which a bar code to be read is scanned with a plurality of beams. FIG. 7A is a perspective view of a raster scan type bar code reader 200.
The bar code reading device 200 includes a semiconductor laser 10, a collimator lens 15, a mirror 17, and a polygon mirror 2.
0, a condenser lens 25, and a light receiving unit 30. In addition, each reflecting surface of the polygon mirror 20 has a rotary shaft 2
Different angles α degrees and the like (here, −1.
It is formed at 5 degrees to about 1.5 degrees (FIG. 7B).

The operation of the raster scan type bar code reader 200 will be described. Irradiation light 10L emitted from the semiconductor laser 10 in the vertical direction is
After being converged by the collimator lens 15, it is converted into substantially parallel light by the mirror 17, and the polygon mirror 20
It is irradiated on the reflective surface of.

Here, the polygon mirror 20 is indicated by an arrow 300.
The polygon mirror 20 is rotated at a high speed in this direction, and the angle of each reflecting surface of the polygon mirror 20 with respect to the mirror 17 is sequentially changed. Irradiation light 1 applied to the reflecting surface of the polygon mirror 20
0L is scanned at a high speed on the barcode 45 in the direction of arrow 350 by the rotation of the polygon mirror 20 in the direction of arrow 300. That is, different scanning (raster scanning) is performed on the bar code 45 for each reflecting surface (FIG. 7A).
reference).

Irradiation light 10 scanned on the bar code 45
L is reflected including the shade of the code (such as the interval between black and white portions). The reflected light (reflected light 10R) reaches the polygon mirror 20 while being diffused, and is given to the condenser lens 25 by being rotated in the direction of the arrow 300. Condensing lens 2
The reflected light 10R collected by 5 is narrowed down and given to the light receiving unit 30.

The light receiving section 30 receives the reflected light 10R from the condenser lens 25, and identifies the product with the bar code 45 based on the shading included in the reflected light 10R. In this way, the bar code can be reliably read.

In order to perform the raster scan, in the above, the respective reflecting surfaces of the polygon mirror 20 are different from the rotating shaft 20C by different angles α degrees (for example, -1.5 degrees to 1.5 degrees).
The degree is about). On the other hand, there is also a method in which each reflecting surface of the polygon mirror 20 is formed parallel to the central axis 20d, and the central axis 20d is inclined by β degrees (for example, about 1 degree) with respect to the rotation axis 20C and fixed. (FIG. 7C).

[0009]

However, the above raster scan type bar code reader has the following problems.

In the raster scan type bar code reader 200, a mirror 17 is provided on the optical path of the reflected light 10R given to the condenser lens 25 (FIG. 7A). Therefore, the reflected light 10R is blocked by the mirror 17 before being condensed by the condenser lens 25. That is, a shadow of the mirror 17 is formed on the condenser lens 25, and the reflected light 10R is not condensed at the shadow portion. Particularly, the portion blocked by the mirror 17 is reflected light 1
Since there is the strongest signal in 0R, there is a problem that the accurate reading cannot be performed due to the blocking of such a part.

Further, as described above, in the raster scan type bar code reader 200, the semiconductor laser 1 is used.
0, the collimator lens 15 and the mirror 17 are provided in the vertical direction. Therefore, the irradiation light 10L is reflected by the polygon mirror 20, and the barcode 45 is scanned,
Further, in order to accurately read the bar code 45 included in the reflected light, each of the semiconductor laser 10, the collimator lens 15, and the mirror 17 has to be adjusted accurately, which is troublesome. In particular, the above-mentioned mirror 17
The mirror 17 is formed to be small in order to minimize the shadow caused by the light. For this reason, there is a problem that it takes a lot of time to accurately adjust each of the above parts.

Further, as shown in FIG. 7B, it is not easy to process the respective reflecting surfaces of the polygon mirror 20 at different angles with respect to the rotary shaft 20C, which causes an increase in processing cost. In addition, as shown in FIG. 7C, the polygon mirror 2
When the center axis of 0 is fixed to the rotating shaft 20C at a predetermined angle, the center of gravity of the polygon mirror 20 and the rotating shaft 20C are fixed.
Is difficult to match. For this reason, there is a problem that an excessive load is applied to the motor due to the weight of the polygon mirror 20 in the rotation after being fixed.

Therefore, an object of the present invention is to provide a code reading device which can perform accurate reading and which can be easily adjusted.

[0014]

A code reading device according to a first aspect of the present invention has an irradiation means for emitting irradiation light and a plurality of reflecting surfaces, each reflecting surface being formed at a different angle with respect to a rotation axis. The irradiation light reflecting means for irradiating the reading object while scanning the irradiation light by the rotation about the rotation axis, and the deviation from the reflection surface of the irradiation term reflection means by a predetermined angle in the rotation direction and the rotation axis. It has a plurality of reflecting surfaces parallel to each other, and is configured so as to reflect the read reflected light from the reading object toward the light receiving means by rotating about the rotation axis as compared with the irradiation light reflecting means. And a sufficiently large read reflected light reflecting means, and a light receiving means provided at a position different from the irradiating means on a plane perpendicular to the rotation axis.

A code reading device according to a second aspect is the code reading device according to the first aspect, wherein the irradiation light reflecting means is formed as a prism, and a central axis of the prism is fixed to the rotating shaft at a predetermined angle. And each side surface of the prism is substantially parallel to the central axis.

A code reading apparatus according to a third aspect of the present invention is the code reading apparatus according to the first aspect, wherein the reading reflected light reflecting means is separated into an upper reading reflected light reflecting means and a lower reading reflected light reflecting means, and the upper reading reflection is provided. The irradiation light reflection means is provided between the light reflection means and the lower reading reflection light reflection means,
Is characterized by.

According to a fourth aspect of the present invention, there is provided the code reading device according to the second or third aspect, wherein the facing surface of the reading / reflecting light reflecting means is formed perpendicular to the rotation axis, and the irradiation light reflecting means is provided. The facing surface of the means is formed perpendicular to the central axis, and a spacer is provided between the facing surface of the reading reflected light reflecting means and the facing surface of the irradiation light reflecting means.

According to a fifth aspect of the code reading device of the first aspect, the irradiation light reflecting means is formed as a prism, and the central axis of the prism is aligned with the center of the rotation axis. It is fixed, and each side surface of the prism has a different angle with respect to the central axis.

According to a sixth aspect of the present invention, there is provided a code reading apparatus having an irradiation means for emitting irradiation light and a plurality of reflecting surfaces, and having a certain reflecting surface having a predetermined basic angle with respect to the rotation axis.
Each of the other reflecting surfaces is formed at a different angle with respect to the certain reflecting surface, and irradiating light reflecting means for irradiating the reading object while scanning the irradiating light by rotating about the rotating shaft, with respect to the rotating shaft. And a plurality of reflecting surfaces that are substantially parallel to each other, and is configured to reflect the read reflected light from the reading object toward the light receiving means by rotating about the rotation axis, and to the irradiation light reflecting means. It is characterized in that it is provided with a reading / reflecting light reflecting means which is sufficiently heavier than the above, and a light receiving means provided at a position different from that of the irradiation means on a plane including the rotation axis.

[0020]

In the code reading device according to the first to third and fifth aspects, in addition to the reading / reflecting light reflecting means, the irradiation light reflecting means has reflecting surfaces formed at different angles with respect to the rotation axis. Is provided, and the reflection surface of the irradiation light reflection means and the reflection surface of the reading reflection light reflection means are displaced by a predetermined angle. Therefore,
It is possible to make the positions of the irradiation unit and the light receiving unit different from each other without providing a reflecting mirror in the optical path of the reading reflected light while making the optical paths of the irradiation light and the reading reflected light substantially the same.

Further, the reading reflected light reflecting means is formed sufficiently heavier than the irradiation light reflecting means. Therefore, it is easy to match the position of the center of gravity of both reflecting means and the rotation axis.

According to a fourth aspect of the present invention, there is provided a code reading device in which an opposed surface of the read reflected light reflecting means is formed perpendicular to the rotation axis and an opposed surface of the irradiation light reflecting means is perpendicular to the central axis. And a spacer is provided between the facing surface of the reading reflected light reflecting means and the facing surface of the irradiation light reflecting means. Therefore, the irradiation light reflecting means can be fixed to the central axis at a predetermined angle, and the reading reflected light reflecting means can be easily formed.

According to a sixth aspect of the present invention, in addition to the reading / reflecting light reflecting means, the code reading device has a reflecting surface having a predetermined basic angle with respect to the rotation axis, and each of the other reflecting surfaces has the reflecting surface. Irradiation light reflecting means having different angles with respect to the surface are provided. Therefore, it is possible to make the positions of the irradiation means and the light receiving means different without providing a reflecting mirror in the optical path of the reading reflected light while making the optical paths of the irradiation light and the reading reflected light substantially the same.

Further, the reading reflected light reflecting means is formed sufficiently heavier than the irradiation light reflecting means. Therefore, it is easy to match the position of the center of gravity of both reflecting means and the rotation axis.

[0025]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the code reading device according to the present invention will be described below. FIG. 1A is a perspective view showing a bar code reading device 400 of this embodiment. Bar code reader 4
Reference numeral 00 designates a projector 10 and a polygon mirror 2 which are irradiation means.
0 and a light receiver 30 as a light receiving means.

In the present embodiment, the semiconductor laser and the collimator lens are integrally formed in the light projector 10, and the polygon mirror 20 includes the projection polygon mirror 20T1 as the irradiation light reflection means and the read reflection light reflection means. The polygon mirror 20J for light reception as described above is used, and both polygon mirrors are fixed to the rotary shaft 20C. Further, in the light receiver 30, a condenser lens and a light receiving unit are integrally formed.

A plurality of reflecting surfaces are formed on the polygon mirror 20, and the reflecting surface of the projecting polygon mirror 20T1 is formed as small as possible (for example, about the same as the laser spot of the irradiation light, for example, about 3 mm). The reflecting surface of the light-receiving polygon mirror 20J is formed as large as possible.

The reflecting surfaces of the light receiving polygon mirror 20J and the light projecting polygon mirror 20T1 are all formed parallel to the central axis thereof. The light-receiving polygon mirror 20J is fixed so that its central axis coincides with the rotation axis 20C. On the other hand, the projection polygon mirror 20T1
Has its central axis 20TC fixed at a predetermined angle β with respect to the rotary shaft 20C (FIG. 1B). The light-receiving polygon mirror 20J is a light-projecting polygon mirror 20T.
It is formed to be sufficiently heavier than 1.

A plan view of such a bar code reader 400 is shown in FIG. 2A. As is clear from FIG. 2A,
The reflecting surface of the light-receiving polygon mirror 20J is rotated by a predetermined angle α with respect to the reflecting surface of the light-projecting polygon mirror 20T1.
(In the present embodiment, they are provided with a shift of about 25 degrees).

Next, the operation of the bar code reader 400 will be described. First, the irradiation light 10L emitted from the light projector 10 strikes the reflection surface of the projection polygon mirror 20T1 (FIGS. 1A and 2A). The polygon mirror 20 rotates in the direction of arrow 300 about the central axis 20C (see FIGS. 1A and 2A). Therefore, the irradiation light 10L that hits the reflecting surface of the projection polygon mirror 20T is read by the rotation of the polygon mirror 20 and is the barcode 4 to be read.
5 is scanned at high speed in the direction of arrow 350.

Here, the central axis 20TC of the projecting polygon mirror 20T1 is at a predetermined angle β with respect to the rotation axis 20C.
It is fixed (for example, about 1 degree) (Fig. 1
B). Therefore, the irradiation light 10L is subjected to a plurality of different scans (raster scans) on the barcode 45 for each reflection surface of the projection polygon mirror 20T1 (FIG. 1).
(See A). The light receiving polygon mirror 20J is formed sufficiently heavier than the light projecting polygon mirror 20T1. Therefore, the central axis 20TC of the light projecting polygon mirror 20T1 is fixed at a predetermined angle β with respect to the rotation axis 20C, and the motor (not shown) will not be loaded even if it is rotated at a high speed.

On the other hand, the reflected light 10R from the bar code 45
Hits the reflecting surface of the light-receiving polygon mirror 20J while diffusing. As described above, the reflecting surface of the light-receiving polygon mirror 20J is formed to be larger than the reflecting surface of the light-projecting polygon mirror 20T1, and the angle difference (angle α) is maintained between it and the light-projecting polygon mirror 20T1. It is rotating while doing.

As a result, the optical paths of the irradiation light 10L and the reflected light 10R between the polygon mirror 20 and the bar code 45 can be made the same. Therefore, the reflected light 10R
Is reliably incident on the light receiver 30, and the shade of the bar code 45 can be accurately read. As a result, the barcode can be accurately read even when used in a place where the external light is strong.

Depending on the change in the position of the bar code 45 to be read, it is necessary to adjust each part for accurate reading. At this time, the projecting side (projector 1
0 and the projecting polygon mirror 20T1) require adjustment in order to accurately reflect the irradiation light 10L to the reflecting surface of the projecting polygon mirror 20T1 and scan the bar code. On the other hand, the light receiving side (light receiving polygon mirror 2
0J and the light receiver 30) as well, the reflected light 10R is reflected on the reflecting surface of the light-receiving polygon mirror 20J, and the light receiver 3
Adjustment is required to make the incident 0.

For example, the angle adjustment of the reflecting surface of the light projecting polygon mirror 20T1 with respect to the projector 10 and the angle adjustment of the light receiver 30 with respect to the reflecting surface of the light receiving polygon mirror 20J correspond to this. That is, the adjustment in the bar code reading device 400 is performed on the light projecting side (light projector 10 and light projecting polygon mirror 20T1) and the light receiving side (light receiving polygon mirror 20).
J and the light receiver 30) respectively.

Therefore, by using the bar code reading device 400, it is possible to read the bar code without being affected by the external light, easy to adjust, and more accurate.

Further, in this embodiment, the reflecting surface of the projecting polygon mirror 20T1 is formed parallel to the central axis thereof. Therefore, it is possible to easily form the projection polygon mirror 20T1 during processing.

In the above embodiment, the reflecting surface of the projecting polygon mirror 20T1 is β with respect to the rotation axis 20C.
It is formed so that the lower surface, which is the facing surface of the light-receiving polygon mirror 20J, is in contact with the upper surface, which is the facing surface, of the light-projecting polygon mirror 20T1 when fixed by tilting. However, another method may be used as long as the reflecting surface of the light projecting polygon mirror 20T1 can be securely tilted by β degrees with respect to the rotation axis 20C and fixed, for example, as shown in FIG. The lower surface BJ20 may be formed perpendicularly to the rotary shaft 20C, and the spacer SP20 may be sandwiched between the lower surface BJ20 and the upper surface of the projection polygon mirror 20T1. Here, the spacer SP20 is preferably made of a material that does not reflect the irradiation light 10L.

By thus sandwiching the spacer SP20 between the lower surface BJ20 of the light receiving polygon mirror 20J and the upper surface of the light projecting polygon mirror 20T1, it is not necessary to form the lower surface BJ20 of the light receiving polygon mirror 20J obliquely. , Processing becomes easier.

In the above embodiment, the light projecting polygon mirror 20T1 is positioned below the light receiving polygon mirror 20J. However, if the barcode 45 can be reliably read, the light projecting polygon mirror 20T1 may be located above the light receiving polygon mirror 20J.

Next, another embodiment of the bar code reader according to the present invention will be described. FIG. 3A shows a side view of the polygon mirror 20 used in this embodiment. Also in this embodiment, the light-receiving polygon mirror 20J and the light-projecting polygon mirror 20T2 are fixed to the rotary shaft 20C as in the above-described embodiments. In this embodiment as well, the reflecting surface of the light-receiving polygon mirror 20J is the light-projecting polygon mirror 20.
It is provided so as to be offset from the reflecting surface of T2 by a predetermined angle α in the rotation direction.

However, in the bar code reader according to the present embodiment, the central axis 20TC of the light projecting polygon mirror 20T2 is fixed so as to coincide with the center of the rotating shaft 20C, and each side surface of the light projecting polygon mirror 20T2 is fixed. Center axis 2
They were formed at different angles with respect to 0TC.

FIG. 3B shows a projection polygon mirror 20T2.
A side view showing the relationship between one reflection surface and its central axis 20TC is shown. Here, one reflecting surface of the projecting polygon mirror 20T2 is formed at an angle γ with respect to the central axis 20TC. The other reflecting surface of the light projecting polygon mirror 20T2 is formed so as to have an angle slightly different from the central axis 20TC.

The operation of the bar code reader of this embodiment is as follows.
The operation is similar to that of the barcode reading device 400 described above.

A polygon mirror 2 for projecting light as in this embodiment
When 0T2 is formed, the lower surface BJ of the light-receiving polygon mirror
It is not necessary to form 20 obliquely (see FIG. 2B), and processing is easy.

In this embodiment, the light projecting polygon mirror 20T2 is located below the light receiving polygon mirror 20J. But surely barcode 4
5 can be read, the light projecting polygon mirror 20T2 may be located above the light receiving polygon mirror 20J.

Next, a perspective view showing another embodiment of the bar code reading apparatus according to the present invention is shown in FIG. 4A. The bar code reading device 600 according to this embodiment also includes a light projector 10, a polygon mirror 20, and a light receiver 30. Further, in the projector 10, a semiconductor laser and a collimator lens are integrally formed, and in the light receiver 30, a condenser lens and a light receiving unit are integrally formed.

However, the polygon mirror 20 of this embodiment
Has a structure in which the light-receiving polygon mirror is provided separately to the first light-receiving polygon mirror 20J1 and the second light-receiving polygon mirror 20J2, and the light-projecting polygon mirror 20T3 is sandwiched between the both light-receiving polygon mirrors. Has become. Here, the light projecting polygon mirror 20T3 is fixed to the rotary shaft 20C with β degrees with respect to the central axis thereof.

A side view of such a polygon mirror 20 is shown in FIG. 4B. Also in this embodiment, the light projecting polygon mirror 20T3 is formed as small as possible, and the first light receiving polygon mirror 20J1 and the second light receiving polygon mirror 20J2 are formed as large as possible. Also,
The light-projecting polygon mirror 20T3, the first light-receiving polygon mirror 20J1, and the second light-receiving polygon mirror 20J2 have a predetermined angle α with respect to the rotation direction (in the present embodiment,
They are offset by about 25 degrees (see FIG. 2A).

Further, in this embodiment, the lower surface of the first light receiving polygon mirror 20J1 is provided on the light projecting polygon mirror 20T3.
Second light receiving polygon mirror 20 so as to contact the upper surface of the
The upper surface of J2 is formed so as to contact the lower surface of the projecting polygon mirror 20T3.

However, another method may be used as long as the reflecting surface of the projecting polygon mirror 20T3 can be securely tilted by β degrees with respect to the rotation axis 20C and fixed, for example, as shown in FIG. 4C. Lower surface BJ20N, which is the facing surface of the second polygon mirror 20J1 and the second light receiving polygon mirror 2
The lower surface BJ20M as the facing surface of 0J2 is attached to the rotary shaft 20C.
And a spacer SP20N between the upper surface and the lower surface as opposed surfaces of the projection polygon mirror 20T3.
Alternatively, the spacer SP20M may be sandwiched. Here, the spacer SP20N and the spacer SP
20M is preferably a material that does not reflect the irradiation light 10L.

In this way, the spacer SP20N is sandwiched between the lower surface BJ20N of the first light receiving polygon mirror 20J1 and the upper surface of the light projecting polygon mirror 20T3, and the spacer SP20M is used for projecting with the upper surface BJ20M of the second light receiving polygon mirror 20J2. If sandwiched between the lower surfaces of the polygon mirror 20T3, it is not necessary to form the lower surface and the upper surface of both light-receiving polygon mirrors obliquely, and the processing becomes easier.

The operation of the bar code reading apparatus 600 of this embodiment is similar to the operation of the bar code reading apparatus 400 described above.

In this embodiment, the first light receiving polygon mirror 20 is used to supply the reflected light 10R to the light receiver 30.
Two of J1 and the second light receiving polygon mirror 20J2 are used. Therefore, the reflected light 10R can be applied to the light receiver 30 more accurately. That is, the barcode can be more accurately read even when used in a place where the external light is strong.

Further, the adjustment of each part in this embodiment is also
Projecting side (projector 10 and projecting polygon mirror 20T
3) and the light receiving side (first light receiving polygon mirror 20J1, second light receiving polygon mirror 20J2, and light receiver 30), respectively. That is, when the bar code reading device 600 is used, the bar code is not affected by external light, the adjustment is easy, and the bar code can be read more accurately.

Further, the projection polygon mirror 2 of this embodiment is used.
Instead of 0T3, the projection polygon mirror 2 shown in FIG.
The polygon mirror 20 may be formed by inserting 0T2 between the first light receiving polygon mirror 20J1 and the second light receiving polygon mirror 20J2.

Next, another embodiment of the bar code reader according to the present invention will be described. FIG. 5A is a side view showing the configuration of the barcode reading apparatus 700 according to this embodiment. For convenience of description, the bar code is not shown here. Also in this embodiment, the bar code reading device 700 includes the projector 1.
0, a polygon mirror 20, and a light receiver 30. The light projector 10 is integrally formed with a semiconductor laser and a collimator lens, and the light receiver 30 is integrally formed with a condenser lens and a light receiving unit. . The polygon mirror 20 is formed with a light projecting polygon mirror 20T4 and a light receiving polygon mirror 20J, each of which has a plurality of reflecting surfaces.

In the embodiment shown in FIG. 2, the reflecting surface of the light-receiving polygon mirror 20J is a light-projecting polygon mirror 20.
It is provided with a predetermined angle α (in this embodiment, about 25 degrees) shifted in the rotational direction with respect to the reflecting surface of T1. As a result, the positions of the light projector 10 and the light receiver 30 on the plane perpendicular to the rotation axis 20C are displaced. On the other hand, in this embodiment, the light-receiving polygon mirror 20J and the light-projecting polygon mirror 20T1 are not displaced in the rotational direction. Figure 5
As shown in A, each reflecting surface of the projecting polygon mirror 20T4 is inclined by a basic angle ε with respect to the rotation axis 20C. Thereby, the rotating shaft 20 of the projector 10 and the light receiver 30
The position in the plane including C is shifted (see FIG. 5A).

That is, the optical path as shown in FIG. 7A can be formed without using the mirror 17. Therefore, the portion of the reflected light 10R having the strongest signal is reliably received by the light receiver 30. As a result, accurate reading can be performed and adjustment is easy.

Further, in the present embodiment, each reflecting surface of the light projecting polygon mirror 20T4 is formed at a slightly different angle based on the above basic angle ε. That is, as shown in FIGS. 6A and 6B, the angle of each reflecting surface is ε.
It is represented by + Δε, and Δε is different for each reflecting surface.
This realizes raster scan. In addition,
Also in this embodiment, the same effect as that of each of the above embodiments can be obtained.

In the above embodiment, the light projecting polygon mirror 2 is used.
Each reflecting surface of 0T4 is formed at a slightly different angle based on the basic angle ε to realize the raster scan. However, the angles of the respective reflecting surfaces are all set to the basic angle ε, and as shown in FIG.
By forming the lower surface of J in a slanted manner, the projection polygon mirror 20T4 may be tilted to realize raster scanning. Further, as shown in FIG. 2B, the light projecting polygon mirror 20T4 may be tilted by the spacer SP20 to realize the raster scan. By doing so, it is not necessary to form the lower surface of the light-receiving polygon mirror 20J obliquely, and processing is easy.

[0062]

In the code reading device according to the first to third and fifth aspects, in addition to the reading reflected light reflecting means, there is provided a reflecting surface having a predetermined basic angle with respect to the rotation axis. However, each of the other reflecting surfaces is provided with irradiation light reflecting means having a different angle with respect to the certain reflecting surface. Therefore, it is possible to make the positions of the irradiation means and the light receiving means different without providing a reflecting mirror in the optical path of the reading reflected light while making the optical paths of the irradiation light and the reading reflected light substantially the same.

Further, the reading reflected light reflecting means is formed sufficiently heavier than the irradiation light reflecting means. Therefore, it is easy to match the position of the center of gravity of both reflecting means and the rotation axis. In other words, it is possible to perform reliable reading that is not affected by outside light and that is easy to adjust.

According to a fourth aspect of the present invention, in the code reading device, the facing surface of the read reflected light reflecting means is formed perpendicular to the rotation axis and the facing surface of the irradiation light reflecting means is perpendicular to the central axis. And a spacer is provided between the facing surface of the reading reflected light reflecting means and the facing surface of the irradiation light reflecting means. That is, the irradiation light reflecting means can be fixed to the central axis at a predetermined angle, and the reading reflected light reflecting means can be easily formed. Therefore, the adjustment is easy and the reliable reading can be performed.

According to a sixth aspect of the present invention, in addition to the reading / reflecting light reflecting means, the code reading device has a certain reflecting surface having a predetermined basic angle with respect to the rotation axis, and each of the other reflecting surfaces has the certain reflecting surface. Irradiation light reflecting means having different angles with respect to the surface are provided. Therefore, it is possible to make the positions of the irradiation means and the light receiving means different without providing a reflecting mirror in the optical path of the reading reflected light while making the optical paths of the irradiation light and the reading reflected light substantially the same.

Further, the reading reflected light reflecting means is formed sufficiently heavier than the irradiation light reflecting means. Therefore, it is easy to match the position of the center of gravity of both reflecting means and the rotation axis. In other words, it is possible to perform reliable reading that is not affected by outside light and that is easy to adjust.

[Brief description of drawings]

FIG. 1 is a side view showing a configuration of a bar code reading apparatus according to the present invention and a side view showing a configuration of a polygon mirror.

2A and 2B are a side view showing a configuration of the bar code reading apparatus shown in FIG. 1 and a side view showing another embodiment of a polygon mirror.

3A and 3B are a side view of a polygon mirror 20 used in another embodiment of the bar code reading apparatus according to the present invention and a side view showing a relationship between a reflecting surface and a central axis 20.

FIG. 4 is a perspective view showing another embodiment of the bar code reader according to the present invention and a side view of a polygon mirror 20 used in the embodiment.

5A and 5B are a side view and a plan view showing the configuration of another embodiment of the barcode reading apparatus according to the present invention.

FIG. 6 is a side view showing an angle of a reflecting surface of a projecting polygon mirror used in another embodiment of the bar code reading device according to the present invention.

FIG. 7 is a perspective view showing a configuration of a conventional barcode reading device 200 and a side view of a polygon mirror 20 used therein.

[Explanation of symbols]

 10: Light projector 20: Polygon mirror 30: Light receiver 45: Bar code 10L: Irradiation light 10R: Reflected light 20C ...・ ・ ・ Rotation axis 20J ・ ・ ・ Receiving polygon mirror 20T1 ・ ・ ・ ・ Projecting polygon mirror

Claims (6)

[Claims] 1. An irradiation means for emitting irradiation light, comprising a plurality of reflecting surfaces, each reflecting surface being formed at a different angle with respect to a rotation axis, and the object to be read by rotation about the rotation axis. Irradiation light reflecting means for irradiating while irradiating irradiation light, having a plurality of reflecting surfaces parallel to the rotation axis while being displaced by a predetermined angle in the rotation direction with respect to the reflecting surface of the irradiation light reflecting means, The reading reflected light reflecting means from the object to be read is reflected toward the light receiving means by rotating about the rotation axis, and the reading reflected light reflecting means is heavier than the irradiation light reflecting means. A light receiving means provided at a position different from the irradiating means in a plane perpendicular to the code reading device. 2. The code reading device according to claim 1, wherein the irradiation light reflecting means is formed as a prism, and the central axis of the prism is fixed to the rotation axis at a predetermined angle, A code reader characterized in that each side surface is substantially parallel to the central axis. 3. The code reading device according to claim 1, wherein the reading reflected light reflecting means is separated into an upper reading reflected light reflecting means and a lower reading reflected light reflecting means, and the upper reading reflected light reflecting means and the lower portion. The code reading device, wherein the irradiation light reflecting means is provided between the reading reflected light reflecting means. 4. The code reading device according to claim 2 or 3, wherein the facing surface of the reading reflected light reflecting means is formed perpendicular to the rotation axis, and the facing surface of the irradiation light reflecting means is formed into the opposite surface. A code reading device, which is formed perpendicularly to a central axis, and a spacer is provided between a facing surface of the reading reflected light reflecting means and a facing surface of the irradiation light reflecting means. 5. The code reading device according to claim 1, wherein the irradiation light reflecting means is formed as a prism, and the central axis of the prism is fixed so as to coincide with the center of the rotation axis. A code reading device characterized in that each side surface of the prism has a different angle with respect to a central axis. 6. Irradiating means for emitting irradiation light, having a plurality of reflecting surfaces, having a certain reflecting surface having a predetermined basic angle with respect to a rotation axis, and each of the other reflecting surfaces being the same. Irradiation light reflecting means that is formed at different angles with respect to the reflection surface and that irradiates the reading means while scanning the irradiation light by rotating about the rotation axis, and a plurality of reflection surfaces that are substantially parallel to the rotation axis. And is configured to reflect the read reflected light from the read object toward the light receiving means by rotating about the rotation axis, and the read reflected light sufficiently heavier than the irradiation light reflecting means. A code reading device comprising: a reflection unit; and a light receiving unit provided at a position different from the irradiation unit on a plane including the rotation axis.