JPH0833905B2 - Bar code reader - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention scans a light beam using a rotating polygon mirror,
The present invention relates to a bar code reading device that receives reflected light from a bar code symbol on an object to be scanned and reads bar code information.

[Prior Art] As a barcode reading device, a rotary polygon mirror and a plurality of fixed plane mirrors are arranged in a housing with a height of 120 mm or less and a width of 210 mm or less, and the scanning pattern on the surface to be scanned is as shown in FIG. As shown in, a plurality of X-shaped scanning patterns having different crossing angles 33 across the product moving direction 32, and a plurality of parallel linear shapes intersecting most or all of the plurality of X-shaped scanning patterns. There is a scan pattern which is a combination of the scan patterns 34, 35 and 36.

In the conventional barcode reader of this type, the third
As shown in the figure, after the reflected light 48 from the bar code symbol on the object to be scanned is condensed by the condenser lens 46 or the like, the fixed plane mirror is arranged in front of the rotary polygon mirror 42 (the traveling direction of the received light).
The light is reflected by 41 or the like to change the direction, and received by the photoelectric conversion element 47 arranged in the lateral direction or the vertical direction of the condenser lens 46. In addition, 44 is a light emitting source and 50 is a light beam.

[Problems to be Solved by the Invention] In the conventional barcode reading apparatus as described above, after the reflected light from the barcode symbol on the scanned object is condensed by the condenser lens or the like, Since the fixed plane mirror 41 is arranged to change the direction in the horizontal direction or the vertical direction, the fixed plane mirror obstructs the light receiving optical path of the reflected light from the bar code symbol on the object to be scanned. There is a drawback that the performance is deteriorated, and the arrangement of parts is complicated, and the apparatus is expensive.

[Means for Solving the Problems] In order to solve the above-mentioned problems, a barcode reading apparatus of the present invention includes a light source, a perforated condenser lens, a rotating polygon mirror, a plurality of fixed plane mirrors, and photoelectric conversion. In a bar code reading device comprising an element and scanning the light beam from the light source by reflecting the light on the rotating polygon mirror and receiving reflected light from a bar code symbol on a scanned object to read bar code information. A light beam from the light source passes through a light passage portion provided in at least one of the fixed plane mirrors and a hole portion of the perforated condenser lens, is reflected by the rotary polygon mirror, and is scanned. The plurality of fixed plane mirrors are arranged so that the scanning pattern on the surface to be scanned by the light beam to be scanned includes at least a plurality of X-shaped scanning patterns having different intersecting angles, and a bar on the surface to be scanned is arranged. -Reflected light from the code symbol is reflected in the order of the fixed plane mirror and the rotary polygon mirror, and after being condensed by the perforated condenser lens arranged in front of the reflective surface of the rotary polygon mirror, the light is passed therethrough. The photoelectric conversion element arranged in front of the light passage portion receives light.

[Embodiment] An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows a bar code reader 30 according to an embodiment of the present invention.
Shows the configuration of. Further, FIG. 2 shows a sectional view when the central portion of the barcode reading device 30 is cut along a vertical plane.

The rotary axis of the rotary polygon mirror 7 is arranged so as to be tilted upward with respect to the bottom surface of the device, and five fixed plane mirrors 8 are arranged in the lateral direction of the rotary polygon mirror 7.
~ 12 and three fixed plane mirrors 13 to 15 are arranged in front of the rotary polygon mirror 7. In this case, these fixed plane mirrors 8 to 15 are provided with a plurality of X-shaped scanning patterns having different crossing angles, including an X-shaped scanning pattern having an intersection angle of 50 degrees or less in the product movement direction. Most of the scanning pattern groups,
Alternatively, it is arranged so as to form a scanning pattern on the scanning surface, which is a combination of linear scanning patterns that intersect with all the scanning patterns. Further, as well shown in FIG. 2, in front of the reflecting surface of the rotary polygonal mirror 7 (the received light Condensing lens 16 in the direction of travel
And the photoelectric conversion element 17 is arranged in front of the condenser lens 16 (in the traveling direction of the received light).

Here, the scanned object may be in contact with the reading window 29 or may be in the space above it. First
In FIG. 2 and FIG. 2, the scanned object exists in the space above. Therefore, the scanning surface 21 also exists in the space above the reading window 29. Further, in FIG. 2, the fixed plane mirrors 8, 9 and 15 are omitted.

In this configuration, the light beam 20 emitted from the light source 1
Is reflected by the fixed plane mirror 2, transmitted through the convex lens 3 and the convex lens 4, then reflected by the fixed plane mirror 5, passes through the concave portion of the fixed plane mirror 14, and passes through the hole of the perforated condenser lens 6 to rotate. It is incident on the polygon mirror 7. The light beam 20 incident on the rotary polygon mirror 7 is scanned in the order of the fixed plane mirror 8, the fixed plane mirror 9, the fixed plane mirror 10, the fixed plane mirror 11, and the fixed plane mirror 12 as the rotary polygon mirror 7 rotates.

The light beam 20 scanned onto the fixed plane mirror 8 is
It is reflected to the scanning plane 21 from this fixed plane mirror 13.
Reflected in. Then, this light beam 20 is X-rayed on the scanning surface 21.
Form scanning pattern 22.

Further, the light beam 20 scanned by the fixed plane mirror 9 is reflected by the fixed plane mirror 14 and further reflected by the scanning plane 21 from the fixed plane mirror 14. This light beam 20 becomes an X-shaped scanning pattern 23 on the scanning surface 21 where the intersection angle across the product moving direction is within 50 degrees.

Further, the light beam 20 scanned on the fixed plane mirror 10 is reflected by the fixed plane mirror 15, the fixed plane mirror 14, and the fixed plane mirror 13. Then, the light is reflected from the fixed plane mirror 15 to the scanning surface 21. Then, an X-shaped scanning pattern 24 is formed on the scanning surface 21.
Further, the light is reflected from the fixed plane mirror 14 to the scanning surface 21. Then, a linear scanning pattern 25 is formed on the scanning surface 21. Further, the light is reflected from the fixed plane mirror 13 to the scanning surface 21. Then, an X-shaped scanning pattern 26 is formed on the scanning surface 21.

Next, the light beam 20 scanned on the fixed plane mirror 11 is reflected by the fixed plane mirror 14 and further reflected by the scanning plane 21 from the fixed plane mirror 14. The light beam 20 forms an X-shaped scanning pattern 27 on the scanning surface 21 where the intersection angle across the product movement direction is within 50 degrees.

Next, the light beam 20 scanned to the fixed plane mirror 12 is reflected by the fixed plane mirror 15, and further, the scanning plane 21 from the fixed plane mirror 15.
Is reflected to. Then, the light beam 20 is transmitted to the scanning surface 21.
The above becomes the X-shaped scanning pattern 28.

Further, the reflected light 18 from the bar code symbol 19 on the scanned object returns to the rotary polygon mirror 7 in the route opposite to the light beam 20. Then, the reflected light 18 is returned from the rotary polygon mirror 7 to the perforated condenser lens 6 arranged in front of the reflection surface of the rotary polygon mirror 7 (the traveling direction of the received light), and is further condensed. After being condensed again by the condenser lens 16 arranged in front of 6 (the traveling direction of the received light), it is returned to the photoelectric conversion element 17 arranged in front of the condenser lens 16 (the traveling direction of the received light) to receive light, It is read as barcode information.

The linear scanning pattern 25 described above may be a plurality of linear scanning patterns that are parallel to each other.

In this embodiment, two lenses, that is, the perforated condenser lens 6 and the condenser lens 16 are used, but it is possible to receive light even if only the perforated condenser lens 6 is used. Further, although the rotary polygon mirror is used to scan the light beam in this embodiment, a hologram disk may be used instead of the rotary polygon mirror to scan the light beam.

[Effects of the Invention] As described above, according to the present invention, after collecting the reflected light from the barcode symbol on the scanned object, the photoelectric conversion element receives the reflected light without changing the direction of the light. Therefore, it becomes possible to receive the reflected light from the barcode symbol on the scanned object without loss. As a result, the reading performance of the barcode reading device is improved. Further, since one fixed plane mirror is not necessary, the arrangement of parts can be simplified and an inexpensive bar code reading device can be provided.

[Brief description of drawings]

1 is a partially cutaway perspective view of an embodiment of the present invention, FIG. 2 is a vertical sectional view of FIG. 1, FIG. 3 is a plan view showing a conventional technique, and FIG. 4 is a product moving direction and scanning. It is a partial top view which showed the intersection angle of a pattern. DESCRIPTION OF SYMBOLS 1 ... Light source 6 ... Condensing lens with a hole 7 ... Rotating polygon mirror 8-15 ... Fixed plane mirror 17 ... Photoelectric conversion element 18 ... Reflected light from a bar code symbol 19 ... Bar code symbol 20 on a scanned object ... Light beam 21 ... Scanning surface 22, 23, 24, 26, 27, 28 ... X-shaped scanning pattern 30 ... Bar code reader 33 ... Crossing angle

Claims (1)

[Claims] 1. A light source, a perforated condenser lens, a rotary polygonal mirror, a plurality of fixed plane mirrors, and a photoelectric conversion element. The light beam from the light source is reflected by the rotary polygonal mirror to scan. A bar code reading device that receives reflected light from a bar code symbol on an object to be scanned and reads bar code information, wherein a light beam from the light source is passed through at least one fixed plane mirror; The scanning pattern on the surface to be scanned by the light beam scanned by the rotary polygon mirror that passes through the hole portion of the perforated condenser lens and is scanned by the rotary polygon mirror has a plurality of crossing angles different from each other. The plurality of fixed plane mirrors are arranged so as to include the X-shaped scanning pattern, and the reflected light from the barcode symbol on the surface to be scanned is reflected in the order of the fixed plane mirror and the rotary polygon mirror. After the light is condensed by the perforated condenser lens arranged in front of the reflecting surface of the rotary polygon mirror, the light is passed through the light passing portion, and by the photoelectric conversion element arranged in front of the light passing portion. A bar code reader characterized by receiving light.