JPH03129582A - Bar code reader - Google Patents

Abstract

PURPOSE:To obtain a miniaturized and universally readable bar code reader by forming plural multi-directional scanning patterns by means of a drum type polygon mirror and dividing respective scanning patterns by a polygon reflecting mirror to form many multi-directional scanning patterns. CONSTITUTION:The drum type polygon mirror 6' for forming plural multi- directional scanning patterns is used for a scanning pattern forming means 6, plural multi-directional scanning patterns are generated by the polygon mirror 6' itself, and when the mirror 6' is used together with a polygon mirror 8', many multi-directional scanning patterns can be generated by the miniaturized configuration. Even in the case of using such a polygon mirror 8', plural multi- directional scanning patterns can be generated by means of the drum type polygon mirror 6'. Namely even when the number of faces of the polygon mirror 8 is small, many multi-directional scanning patterns can be generated and the device can be miniaturized.

Description

[Detailed Description of the Invention] [Table of Contents] Overview Industrial Application Fields Conventional Technology (Figures 10 and 11) Means for Solving the Problems to be Solved by the Invention (Figure 1) Working Examples (a) Description of one embodiment (Figures 2 to 8)
Description of another embodiment (FIG. 9) (C) Description of another embodiment Effects of the invention [Summary] Regarding a barcode reading device that optically scans a barcode symbol and receives reflected light from the barcode symbol, The purpose of the present invention is to realize a large number of multidirectional scanning patterns with a compact configuration, and includes a light source that emits a light beam, a scanning pattern forming means that forms a scanning pattern from the light beam, and a scanning pattern that reflects the scanning pattern. A reflective mirror that guides the barcode symbol,
A barcode reading device comprising a condensing means for condensing light reflected by the barcode symbol and a light receiving sensor for receiving the condensed light and converting it into an electrical signal, the scanning pattern forming means is constructed of a drum-shaped polygon mirror that has reflective surfaces on the upper and lower sides and forms a plurality of multidirectional scanning patterns, and the reflective mirror is constructed of a multifaceted mirror that further divides the scanning pattern into a plurality of scanning patterns. Intimidated.

[Industrial application field]

The present invention relates to a barcode reading device that optically scans a barcode symbol and receives reflected light from the barcode symbol.

PoS systems (point-of-sale systems) have been introduced in department stores, supermarkets, etc. for the purpose of streamlining product management and checkout operations.

In such systems, in order to automate product input, barcodes are attached to products and the barcodes are read by a barcode reading device.

Barcode reading devices include stationary devices that emit a plurality of scanning patterns and handheld devices that emit a single scanning beam.

Generally, large stores such as supermarkets use stationary devices, but small stores use small handheld devices because the devices are large and require a large installation space.

However, with a handheld device, the device must be held in the hand during scanning, and there is only one scanning beam, so the operability is not as good as that of a stationary device.

For this reason, there is a demand for a stationary device that is compact and capable of drawing scanning beams in more directions.

[Conventional technology]

FIGS. 10 and 11 are explanatory diagrams of the prior art.

Laser light from a laser light source 1 such as a semiconductor laser is emitted through a hole in a reflective roller 12 to a polygon mirror (scanning pattern forming means) 6 rotated by a polygon motor 7, and the rotation of the polygon mirror 6 forms a scanning pattern. formed,
The light is emitted to a barcode symbol BS via a reflection mirror 8.

The reflected light from the barcode symbol BS (dotted line in the figure) is
The light is reflected by a polygon mirror 6 via a reflection mirror 8, condensed by a condenser lens 9, received by a light receiving sensor 10 via a reflection mirror 12, and converted into an electrical signal. Note that 11 is a casing that accommodates these.

By the way, the polygon mirror 6 can only draw a scanning pattern S1 in one direction, as shown in FIG. 11(A).

For this reason, in the prior art, in order to draw a scanning pattern in multiple directions, the reflection mirror 8 is
A polygon mirror 8' having reflection surfaces 8a, 8b, 8C with different reflection angles is used to divide one scanning pattern of the polygon mirror 6 into a plurality of scanning patterns 81 to S3, and to perform scanning in multiple directions. I was getting a scanning pattern.

The number of scanning patterns to be divided is determined by the number of reflective surfaces of the polygon mirror 8'.
), two scanning patterns S1, S! In the case of a three-sided mirror 8', it is divided into three scanning patterns 81 to S3 as shown in FIG. 11(C).

[Problem to be solved by the invention]

By the way, the more the scanning pattern has multiple directions, the more versatile the readability becomes.

In the prior art, the number of scanning patterns is determined by the number of reflective surfaces of the polygonal mirror 8', so in order to obtain scanning patterns in more directions, it is necessary to increase the number of reflective surfaces of the polygonal mirror 8'.

For example, to obtain six multidirectional scanning patterns, the polygon mirror 8' must have six faces.

However, since the polygon-matching -6 scanning pattern is divided by the polygon mirror 8' and becomes a multidirectional scanning pattern, the larger the number of divisions, the more the scanning pattern as shown in FIGS. 11(B) and (C) , the scanning pattern length becomes shorter.

Therefore, in order to obtain the required scanning pattern length in multiple directions, it is necessary to provide a sufficient distance between the polygon mirror 6 and the polygon mirror 8', and the polygon mirror 8' must also be made large accordingly. However, there was a problem in that the device became larger.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a barcode reading device that can realize multiple multidirectional scanning patterns with a compact configuration.

[Means to solve the problem]

FIG. 1 is a diagram showing the principle of the present invention.

As shown in FIG. 1, the present invention includes a light source 1 that emits a light beam, a scanning pattern forming means 6 that forms a scanning pattern from the light beam, and reflects the scanning pattern to guide it to a barcode symbol. A barcode reading device that includes a reflecting mirror 8, a condensing means 9 that condenses the reflected light reflected by the barcode symbol, and a light receiving sensor 10 that receives the condensed light and converts it into an electrical signal. The scanning pattern forming means 6 is constituted by a drum-shaped polygon mirror 6' having upper and lower reflective surfaces 6a and 6b and forming a plurality of multidirectional scanning patterns, and the reflecting mirror 8 is configured to form a plurality of scanning patterns. A multifaceted mirror 8 further divides the image into multiple scanning patterns.
′.

[Effect]

In the present invention, a drum-shaped polygon mirror 6' that forms a plurality of multi-directional scanning patterns is used as the scanning pattern forming means 6 to generate a multi-directional scanning pattern of the polygon mirror b, and is used in combination with the polygon mirror 8'. This makes it possible to generate a large number of multidirectional scanning patterns with a compact configuration.

In this case, it is possible to form scanning patterns in as many directions as the number of surfaces of the drum-shaped polygon mirror 6'.

However, the polygon mirror surface requires a certain area in order to ensure a sufficient amount of returned light, and cannot be made too small.

Therefore, increasing the number of surfaces increases the size of the polygon mirror, making it impossible to miniaturize the device.

Therefore, without increasing the number of surfaces of the drum-shaped polygon mirror 6',
In order to generate more multi-directional scanning patterns, it was used in conjunction with a multi-sided A-ra 8'. Furthermore, since the multi-faceted mirror 8' also generates a plurality of multi-directional scanning patterns with the drum-shaped polygon mirror 6', even if the number of faces is small, a large number of multi-directional scanning patterns can be generated, making the device compact. can be converted into

〔Example〕

(a) Description of one embodiment FIG. 2 is a side view of one embodiment of the present invention, and FIG. 3 is a top view of one embodiment of the present invention.

At the bottom of the casing 11 are a laser light source 1 that emits a laser beam, a focus lens 2 that determines the focal length of the laser beam, and a first reflective reflector 3 that changes the direction of the laser beam that has passed through the focus lens 2 by 90''. , a second reflecting mirror 4 that changes the direction of the laser beam from the first reflecting mirror 3 by 90 degrees, and a drum-shaped polygon that changes the direction of the laser beam from the second reflecting mirror 4 by 90 degrees upward. A lower reflective surface 6a and a polygon motor 7 for rotating the polygon mirror 6' are arranged.

Further, on the right side of the reflecting mirror 4, a condensing lens 9 for condensing the reflected light from the reflecting mirror 5 and a light receiving sensor 10 for receiving the return light from the condensing lens 9 are provided.

On the other hand, on the upper stage of the casing 11, an upper reflective surface 6b of a drum-shaped polygon mirror 6' rotated by a polygon motor 7 and a multifaceted reflective mirror 8' are disposed opposite to the lower reflective surface 6a.
and is provided.

To explain the operation of this embodiment, a laser beam emitted from a laser light source 1 passes through a focus lens 2, is guided to a first reflection mirror 3, a second reflection mirror 4, and is directed to a drum-shaped polygon mirror 6'. This corresponds to the lower reflecting surface 6a.

The laser beam that hits the lower reflective surface 6a of the drum-shaped polygon mirror 6' is guided to the upper reflective surface 6b, is reflected, becomes a scanning beam, is reflected by the polygonal reflective mirror 8', and is reflected to form a barcode symbol. It is emitted to the BS.

After being emitted, the laser beam reflected from the barcode symbol BS returns in this order to the polygonal reflective mirror 8', the upper reflective surface 6b of the drum-shaped polygon mirror 6', and the lower reflective surface 6a, and is condensed by the condensing lens 9. The light is collected by the light receiving sensor 10 and converted into an electrical signal.

This scanning pattern is determined by an hourglass-shaped polygon mirror 6' and a multifaceted reflective mirror 8'.

FIG. 4 is a perspective view of the drum-shaped polygon mirror, FIG. 5 is a configuration diagram of the drum-shaped polygon mirror, and FIG. 6 is an explanatory diagram of a scanning pattern of the drum-shaped polygon mirror.

5<A) is a side view of FIG. 4, and FIG. 5(B) is a front view of FIG. 4.

The drum-shaped polygon mirror 6' is composed of an upper reflective surface 6b and a lower reflective surface 6a, as shown in FIG.
a intersect at an intersection angle θ2 as shown in the side view of FIG. 5(A), and are inclined at an inclination angle θ1 as shown in the front view of FIG. 5(B).

This intersection angle θ! The scanning pattern changes depending on the angle of inclination θ1.

When the intersecting angle θi is changed, scanning patterns S, -S are generated according to the intersecting angle θ2, as shown in FIG. 6(A).

shifts in parallel.

Also, when the inclination angle θ1 is changed, as shown in Fig. 6 (B),
The scanning patterns S□ to sty have different inclinations (directions) about one point depending on the inclination angle θl.

Furthermore, if both the intersection angle θ and the inclination angle θ1 are changed, as shown in FIG. Draw patterns SKI to Ss4.

Therefore, at least by changing the inclination angle θ1 on each surface, a plurality of multidirectional scanning patterns can be drawn.

Furthermore, if the intersection angle θ and the inclination angle θ1 between the upper reflective surface 6b and the lower reflective surface 6a of the drum-shaped polygon mirror 6' are varied on each surrounding surface, a variety of shapes as shown in FIG. 6(C) can be obtained. It is possible to create grooves in a scanning pattern, which increases the degree of freedom in reading the barcode in relation to the orientation of the barcode, which is effective for improving operability.

FIG. 7 is an explanatory diagram of a multifaceted reflective mirror according to an embodiment of the present invention.

As shown in FIG. 7(A), a multifaceted reflective mirror 8' is composed of two reflecting surfaces 8a and 8b.

Here, the generated scanning pattern of the drum-shaped polygon mirror 6' is set to S! of FIG. 7(B). There will be 3 pieces, 1 to sg3.

To generate such a scanning pattern, among the six peripheral drum-shaped polygon mirrors 6' shown in FIG. All you have to do is change it to .

These three scanning patterns SZ+ to S23 are shown in Figure 7(A).
When the light is irradiated onto the two-sided reflective mirror 8', each of the scanning patterns sg+ to S is divided into two as shown in FIG. 7(C).
Six scanning patterns si+-+~sg with different directions
Generate zz.

That is, the scanning pattern S□ is the scanning pattern S.

- In St□-2, scanning pattern S! ! is the scanning pattern S2 and 1.5tt-t, and the scanning pattern SZS is the scanning pattern 5tS-+, S! It is divided into 31 parts.

In this example, two of the six drum-shaped polygon mirrors 6' have the same inclination angle θ1, and the scanning pattern shown in FIG. 7(B) is generated twice in one rotation. This is done to prevent the pattern period from becoming too long.

Therefore, the six-sided drum-shaped polygon mirror 6' generates scanning patterns in three different directions, and the two-sided reflective mirror 8'
Each of these is divided into two to generate a total of six scanning patterns in different directions, and these six-tree scanning patterns are generated twice in one rotation.

Of course, by changing the inclination angle on each of the six surfaces of the drum-shaped polygon roller 6', six scanning patterns are generated, each of which is divided into two by the two-sided reflection mirror 8', for a total of 12 scanning patterns in different directions. Scanning patterns can also be generated.

In this case, 12 scanning patterns are generated once in one rotation of the polygon mirror 6', so if the period of the scanning pattern becomes a problem, it is necessary to increase the rotation speed of the polygon mirror 6'.

In this way, the drum-shaped polygon mirror 6' forms scanning patterns in a plurality of different directions, and this is divided by the polygonal reflection mirror 8' to form scanning patterns in a larger number of different directions. Even if the mirror 6' and the polygonal reflection mirror 8' are made small, scanning patterns in many different directions can be formed.

In this embodiment, a light emitting part (laser light source 1, focus lens 2, reflection mirror 3) and a light collecting part (light collecting lens 9) are used.
, the light receiving sensor 10) is arranged in the lower stage, the scanning pattern forming section (polygon mirror 6' reflecting mirror 8') is arranged in the upper stage, and the upper and lower optical paths are connected by the lower reflecting surface 6a of the polygon mirror 6'. Therefore, the entire upper stage can be used as a scanning pattern forming space, the device can be made smaller, and the condenser lens 9
can be brought closer to the polygon mirror 6', and the condenser lens 9 can be made smaller and thinner.

FIG. 8 is a detailed explanatory diagram of the present invention.

Since the barcode reading device according to the present invention can realize scanning patterns in many different directions with a small and thin configuration, as shown in FIG. Product AS placed vertically and held in hand
barcode BS can be read with a scanning pattern S in multiple directions.

Therefore, the exclusive occupation of the reading device RD is small, and it can be introduced even in small-sized stores.

(b) Description of another embodiment FIG. 9 is an explanatory diagram of a polygonal reflecting mirror according to another embodiment of the present invention.

In this embodiment, the multifaceted surface is also set as 8', as shown in FIG. 9(A).
As shown in the figure, it is composed of a three-sided mirror having three reflecting surfaces 8a, 8b, and 8C.

In this embodiment as well, the drum-shaped polygon mirror 6' is shown in FIG.
) to form three scanning patterns St+ to StS, the three-sided mirror 8' is configured to form three scanning patterns S, to S
0 is divided into three, and a total of nine scanning patterns S, -1 to 523-2 are formed as shown in FIG. 9(C).

That is, the scanning pattern SK+ is the scanning pattern S! I-4
~S tI4, scanning pattern S! ! is the scanning pattern S! The scanning pattern 5tJ3 is divided into scanning patterns 5g5-+-3z*-+ for 5x-3 to 5ix-3.

(C1 Description of Another Embodiment In the above-described embodiment, a six-sided polygon mirror is used, but the number of planes is not limited to this, and the number of multi-sided reflective mirrors is not limited to two or three sides.

Although the present invention has been described above using examples, the present invention can be modified in various ways according to the gist of the present invention, and these are not excluded from the present invention.

〔Effect of the invention〕

As explained above, according to the present invention, a plurality of scanning patterns in multiple directions are formed using an hourglass-shaped polygon mirror, and each of these scanning patterns is divided by a polygonal reflection mirror to form a large number of scanning patterns in multiple directions. Therefore, even if the hourglass-shaped polygon mirror and the multifaceted reflection mirror are small, many multidirectional scanning patterns can be formed, and a barcode reading device that is small and has versatile readability can be provided.

[Brief explanation of the drawing]

Fig. 1 is a diagram of the principle of the present invention, Fig. 2 is a side view of an embodiment of the invention, Fig. 3 is a top view of an embodiment of the invention, and Fig. 4 is the drum shape of Figs. 2 and 3. A perspective view of the polygon mirror, Fig. 5, Fig. 4, the constituent countries of the hourglass-shaped polygon mirror, Fig. 6, an explanatory diagram of the scanning pattern of the hourglass-shaped polygon mirror in Fig. 4, and Fig. 7, the multifaceted reflection of Fig. 2. FIG. 8 is a detailed illustration of the present invention; FIG. 9 is an illustration of a polygonal reflection mirror according to another embodiment of the present invention; FIGS. 10 and 11 are illustrations of the prior art. be. In the figure, 1... - light source (laser light source), 6 - scanning pattern forming means, 6' - drum-shaped polygon mirror 8... reflective mirror 8' - multifaceted reflective mirror 9... collection. Optical means (lens), 10... Light receiving sensor, BS... Barcode symbol.

Claims (1)

[Claims] A light source (1) that emits a light beam, a scanning pattern forming means (6) that forms a scanning pattern from the light beam, and a reflecting mirror that reflects the scanning pattern and guides it to a barcode symbol. (8), a light collecting means (9) that collects the reflected light reflected by the barcode symbol, and a light receiving sensor (10) that receives the collected light and converts it into an electrical signal. In the barcode reading device, the scanning pattern forming means (6) is provided with reflective surfaces (6a
, 6b), and is composed of a drum-shaped polygon mirror (6') forming a plurality of multidirectional scanning patterns, and the reflecting mirror (8) is a multifaceted polygon mirror that further divides the scanning pattern into a plurality of scanning patterns. A barcode reading device comprising a mirror (8').