JPH0823629B2 - Optical reader - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Outline] The present invention is an optical reading device used for reading a bar code in a POS system or the like, in which a bar code attached to a product faces a reading window, is parallel, and Not only when it is moved in a tilted manner, but also when it is moved vertically to the reading surface, it has a universal reading capability that allows the barcode to be read by the light beam, and the device is thin and low-priced. For the purpose of and for a multi-faceted rotating mirror which is located under the reading window and has a plurality of scanning mirrors each having a different inclination angle and which is rotated through a rotary shaft, from the lower side on the other side of the reading window. Is irradiated with the condensed substantially horizontal incident light beam, and the reflected light is received by the corresponding scanning line mirror, and the reflected light from the scanning line mirror passes through the reading windows to obtain different scanning patterns. In the optical reading device for forming a lens, the multifaceted rotating mirror is arranged on the incident light beam line obliquely outside the lower part of the reading window, the rotation axis is inclined in the incident light beam direction, and the horizontal scanning pattern mirror is used as the scanning mirror. In addition to the diagonal scanning pattern mirror, the vertical scanning pattern mirror is provided, and the horizontal scanning line mirror that receives the reflected light from the horizontal scanning pattern mirror and the diagonal scanning pattern mirror that accompanies the rotation of the polyhedral rotating mirror, and A diagonal scanning line mirror is arranged obliquely outside the lower part of the reading window, and its reflected light is made incident on the reading window obliquely from below, and two vertical scannings in which the reflected light from the vertical direction scanning pattern mirror is made incident. The line mirror (32c) allows the respective reflected lights to be incident on the reading window at a predetermined angle from diagonally below and to the reading window. So that a vertical scanning pattern is formed on the vertical surface on the side, and is arranged symmetrically with respect to the incident light beam and spaced apart from each other and obliquely outside the reading window between the reading window and the polygon mirror. To do.

[Industrial applications]

The present invention relates to an optical reader for generating a multi-directional scanning pattern by a light beam and generating a bar code in a POS (Point Of Sales) system.

The number of department stores and supermarkets that introduce POS systems is increasing in order to improve the efficiency of product sales management and checkout work.

This system is a bar code reader (optical reader) that reads a bar code attached to a product by scanning laser light and converts it into an information format convenient for calculation processing.
It is composed of a computer for processing this bar code information and a POS register for relaying information between them and outputting information to the customer.

Such an optical reader is generally a means for irradiating a product held by an operator and moving above a reading window with a laser beam, and scanning the laser beam across a bar code on the product, and a black and white bar. It includes means for detecting reflected light from a bar code having a corresponding light amount level, and means for converting the detected optical signal into an electric signal, decoding the electric signal and converting the electric signal into bar code information.

In order to improve the efficiency of the checkout work, the optical reader is required to have good operability.

Especially when the operator holds the product and reads the bar code by moving it on the device, the bar code label of the product does not need to be aligned in a specific direction, so that it can be read in any direction. It is desired to have a so-called universal reading performance that is possible.

In order to realize universal reading not only for standard symbols but also for truncate symbols that are actually used with the bar length reduced to about half, the scanning pattern emitted from the device is multidirectional scanning. It must consist of lines.

As an example, a horizontal scanning line capable of reading a bar code symbol inclined at or near the horizontal direction, a vertical scanning line effective for reading near the vertical direction,
And a diagonal scan line useful for reading angles in between.

Also, with the recent diversification of checkout systems in supermarkets, compact optical readers with a high degree of freedom in system configuration are desired, and especially in the European market, sitting operation is obligatory. There is a strong demand for a thin optical reader that can be operated while sitting.

[Conventional technology]

FIG. 3 is a side view of an optical reading device using a hologram disk.

A laser beam 2 emitted from a laser tube 1 is converted into a parallel beam 4 having an appropriate diameter by a collimator 3 and then deflected by small mirrors 5 and 6 to form an incident light beam 7 which horizontally travels above a hologram disk 10. Become.

The incident light beam 7 passes through the hole 81 of the perforated lens 8, is reflected by the large mirror 9, and is vertically incident on the hologram disk 10.

A large number of holograms annularly formed on the hologram disk 10 diffract the incident light beam 7 and emit it as a diffracted beam 11 below the hologram disk 10.

The diffracted beam 11 is reflected by a mirror 15 arranged below and directed to a final stage mirror 18.

Subsequently, this beam is reflected by the mirror 18 and passes through the window glass 20 and is emitted obliquely upward from the reading window 21.

When the hologram disk 10 is rotated by the motor 23, the emission beam 22 moves along a path determined by the characteristics of the hologram segment, and scans the bar code label on the article 24 moving in the direction of arrow A over the reading window 21. .

Signal scattered light 25 with a light intensity level according to the black and white of the bar
Radiate from the bar code label in all directions, but part of it travels in the opposite direction on the same path as at the time of ejection.

That is, a part of the signal scattered light 25 returns to the inside of the scanner through the reading window 21 and the window glass 20, is further reflected by the mirror 18, and then the mirror 15, and the hologram disk 10
Reach the hologram segment above.

A part of the signal scattered light 25 reaching the hologram segment is converted into a substantially parallel light beam 27 by the hologram, reflected by the large mirror 9, and then detected by the perforated lens 8 by the detector 28.
Is focused on the detection surface of.

This signal-focused light is converted into an electric signal by the detector 28, and decoded through an A / D converter and a demodulator (not shown).

When the hologram disk 10 rotates and the light beam 7 is incident on another hologram segment in the same manner as described above, the diffracted beam 11 is emitted in a different direction.

Such a case will be described with reference to the plan view of FIG. 3 shown in FIG.

The diffraction beam 11 described in FIG. 3 corresponds to the diffraction beam 111 in FIG. As described above, the diffracted beam 111 is reflected by the mirror 15 and the final stage mirror 18 and emitted from the reading window.

Also, the scanning locus on the mirror 15 is shown by a broken line 111a, and the scanning direction after being reflected by the mirror 18 is shown by a broken line 111b.

As shown by the broken line 111b, the scanning line by the diffraction beam 111 is
It becomes a horizontal scanning line (a substantially horizontal scanning line).

Then, when the segment changes, the diffraction beam moves to 112 or 113.

The diffracted beam 113 is reflected by the mirror 13 and goes to the final stage mirror 19.

 The scanning locus of the mirror 13 is as shown by the broken line 113a.

Then, the light is reflected by the mirror 19 and is emitted from the reading window as a vertical scanning line (described later) for scanning in a substantially vertical direction as shown by a broken line 113b.

The diffracted beam 112 is deflected and emitted on the mirror 16 so as to draw a scanning locus represented by a broken line 112a.

The diffracted beam 112 reflected by the mirror 16 is further reflected by the same final stage mirror 18 as in the case of the diffracted beam 111, and becomes an oblique scanning line (described later) as indicated by a broken line 112b, which is a reading window. Is ejected from.

In FIG. 4, only the diffraction beam on the right side is shown, but it is also symmetrically emitted to the left side.

The beam diffracted symmetrically with the diffracted beam 112 is the mirror 1
4 and the beam which is diffracted by the final stage mirror 18 common to the diffracted beams 111 and 112 and symmetrically with the diffracted beam 113 is
The light is reflected by the mirror 12 and the final stage mirror 17 and emitted from the reading window.

As a result, the scanning patterns in five directions as shown in FIGS. 5 and 6 are combined on the reading window.

That is, FIG. 5 shows the scanning patterns on the final stage mirrors 17, 18, 19 of the scanning pattern synthesizing mirror group and the reading window, and FIG. 6 shows the scanning pattern on the virtual vertical plane 24 ′ with respect to the reading window 21. Shows.

In FIG. 5, (A)-(A '), (B)-
(B '), (C)-(C') are reflected by the final stage mirror 18, and (D)-(D '), (E)-(E') are reflected by the final stage mirrors 17 and 19, respectively. Points are shown.

Then, the diffracted beam 11 reflected by (A)-(A ')
1 scans the reading window 21 shown in FIG. 6 in the horizontal direction aa '.

This becomes the horizontal scanning line indicated by a "-a on the virtual vertical plane 24 '.

Also, the diffraction beam 112 reflected by (B)-(B ')
Scans the reading window 21 in the oblique direction bb '.

This is the oblique scanning line shown by b'-b "on the virtual vertical plane 24 '.

Furthermore, the diffracted beam reflected by (D)-(D ')
113 scans d-d 'on the read window 21.

This becomes a vertical scanning line d'-d "on the virtual vertical plane 24 '.

Similarly, (C)-(C ') is an oblique scanning line of c-c' on the reading window 21, c'-c "on the virtual vertical plane 24 ', and (E)-(E') is Vertical scanning lines e-e 'on the reading window 21 and e'-e "on the virtual vertical surface 24'.

The bar code label surface provided on the article is fed in parallel to the attachment window 21, is vertically fed as shown in FIG. 6, or is fed at an intermediate angle. Therefore, the diffracted beam reflected by the mirror is emitted so as to be substantially perpendicular to a plane that bisects the reading window 21 and the vertical plane 24 ', that is, a plane having an inclination angle of 45 degrees.

As the optical reading device, there is a device using a rotating mirror 29 as shown in a perspective view of FIG. 7 in addition to a device using a hologram disk for deflecting a light beam as described above.

The figure shows a mirror 15 'that emits horizontal scanning lines in the mirror group.
And 18 'are shown, and in addition, a mirror group for oblique scanning lines and a mirror group for vertical scanning lines are provided, and the structure thereof is almost the same as the above description.

The rotating mirror 29 has a conical shape, and has two reflecting surfaces 29a formed at symmetrical positions on the inclined surface thereof, and is provided so that the reflecting surface faces downward.

The laser beam 2 emitted from the laser tube 1 is deflected by the small mirrors 5 ′ and 6 ′ and the large mirror 9 ′, passes through the hole of the perforated lens 8 and enters the rotating mirror 29.

The incident light beam is deflected by the reflecting surface 29a and is emitted to the mirror 15 'arranged below.

Then, it is reflected by the mirror 15 'and directed to the final stage mirror 18'.

Then, this light beam is reflected by the mirror 18 'and emitted obliquely upward from the reading window 21'.

When the rotating mirror 29 is rotated by a motor (not shown), the light beam deflected by the reflecting surface 29a and emitted is moved to another mirror group (not shown), and obliquely upward from the reading window 21 'in a predetermined oblique and vertical scanning pattern. Ejected on the reading window 2
Scan the bar code label on item 24 moving over 1 '.

A part of the signal scattered light having a light amount level corresponding to the black and white of the bar goes backward in the same path as when it was emitted, and the reading window
Return to the inside of Scyana through 21 ', then mirror 18',
Then, it is reflected by the mirror 15 'and reaches the reflecting surface 29a of the rotating mirror 29.

The signal scattered light reaching the reflecting surface 29a is the perforated lens 8 '.
After being focused by, and reflected by the large mirror 9 ', it is focused on the detection surface of the detector 28.

[Problems to be solved by the invention]

As described above, the optical reading apparatus has a mirror group composed of a large number of mirrors, which is extremely expensive including the optical adjustment work, and the final stage mirror is substantially upright in terms of its function. However, there is a problem in that the height of the device becomes high. For this reason, the present invention uses a multi-faceted rotating mirror and has universal reading performance capable of forming not only a horizontal scanning pattern and a diagonal scanning pattern but also a vertical scanning pattern, and the apparatus is thin and low-priced. It is an object of the present invention to realize an optical reading device that enables

[Means for solving problems]

According to the invention the above object is located at the bottom of the reading window,
For a multi-faceted rotating mirror that has a plurality of scanning mirrors each having a different tilt angle and is rotated through a rotating shaft, the incident light beam focused in a substantially horizontal direction from the lower side of the other side of the reading window is In the optical reading device in which the irradiated light is reflected and the reflected light is received by the corresponding scanning line mirror, and the reflected light from the scanning line mirror forms different scanning patterns through the reading window, the multifaceted rotating mirror reads It is placed on the incident light beam line diagonally outside the lower part of the window, and the rotation axis is tilted in the incident light beam direction, and the horizontal scanning pattern mirror, the diagonal scanning pattern mirror, and the vertical scanning pattern mirror are used as scanning mirrors. It is equipped with and receives the reflected light from the horizontal scanning pattern mirror and the diagonal scanning pattern mirror as the multi-faceted rotating mirror rotates. A horizontal scanning line mirror and a diagonal scanning line mirror are arranged obliquely outside the lower part of the reading window, and the reflected light is made incident on the reading window obliquely from below and the reflected light from the vertical direction scanning pattern mirror is made incident. Each of the two vertical scanning line mirrors (32c) has its respective reflected light incident on the reading window at a predetermined angle from below, and a vertical scanning pattern is formed on the vertical surface outside the reading window. As described above, the optical reader is characterized in that it is arranged symmetrically with respect to the incident light beam and spaced apart from each other and obliquely outside the reading window between the reading window and the polygon mirror.

[Action]

In the present invention, a polyhedral rotating mirror that is irradiated with an incident light beam is used. The polyhedral rotating mirror is provided with horizontal and oblique scanning pattern mirrors as well as vertical scanning pattern mirrors and is rotated by a rotary shaft. By using a mirror, it becomes easy to set the inclination angle of the reflecting surface.

The rotation axis of the polygon mirror is inclined in the direction of the incident light beam, and the polygon mirror is arranged obliquely outside the lower part of the reading window, and the scanning line mirror receives the reflected light from each scanning mirror of the polygon mirror. Is also arranged obliquely outside the lower part of the reading window and between the multifaceted rotating mirror and the reading window.

As a result, the reflected light from the scanning line mirror is incident on the reading window obliquely from below, and a scanning pattern is formed not only on the reading window surface as shown in FIG. 6 but also on the vertical surface with respect to the reading window. Also forms a vertical scan pattern.

Since the rotation axis of the multifaceted rotating mirror is tilted, when the incident light beam is incident on the vertical scanning pattern mirror, the incident light beam on the reflecting surface is combined with the tilt angle of the reflecting surface of this mirror. The scanning lines are diagonal.

Further, two vertical scanning line mirrors 32c form a set, and are arranged obliquely outside the lower part of the reading window between the reading window and the multifaceted rotating mirror, and are arranged symmetrically with respect to the incident light beam. ing.

Therefore, when the reflected light from the vertical scanning pattern mirror is incident, the reflected light enters the reading window obliquely from below and intersects with the reading window surface, but a vertical scanning pattern is formed on the surface perpendicular to the reading window. It

Therefore, it is possible to read the barcode even when the barcode of the product is moved vertically.

As described above, in the present invention, the multi-faceted rotating mirror is used, the rotation axis is inclined and rotated, and the vertical direction scanning pattern mirror and the vertical scanning line mirror corresponding thereto are combined in the vertical direction. It becomes possible to form a scanning pattern, and a universal scanning performance is provided together with a horizontal scanning pattern and an oblique scanning pattern by combining other scanning mirrors in the multi-faceted rotating mirror with the corresponding scanning line mirrors.

Further, the tilted arrangement of the rotation axis of the polygon mirror is not only necessary for forming the vertical scanning pattern, but also the substantial height of the polygon mirror is made small, and the arrangement of the polygon mirror makes it possible to scan all the scanning lines. Since the use mirror is arranged in the vicinity of the incident light beam, the optical reader can be made thin.

〔Example〕

1 and 2 show an embodiment of the present invention, and the scanning pattern formed through the reading window in this embodiment is similar to the conventional example and is shown in FIG.

 The same portions are denoted by the same reference numerals throughout the drawings.

In the present invention, the optical reader is shown in the side view of FIG. 1 and the plan view of FIG.

In the figure, 21 is a reading window, 30 is a multi-faceted rotating mirror, 31 is a reflecting surface of the scanning mirror, and the scanning mirrors have different inclination angles, namely, a horizontal scanning pattern mirror and an oblique scanning pattern mirror. In addition to this, it is composed of a vertical scanning pattern mirror.

The scanning mirror has a rotating shaft 33 driven by a motor 34.
The rotary shaft 33 is tilted in the direction of the incident light beam 7 and is arranged obliquely outside the lower portion of the reading window 21.

On the other hand, 32 is a scanning line mirror group, which includes a horizontal scanning line mirror 32a, an oblique scanning line mirror 32b, and a vertical scanning line mirror 32c, both of which are obliquely outside the reading window, and It is arranged between the polygon mirror and the reading window.

Here, as shown in FIG. 2, the laser beam 2 emitted from the laser tube 1 is converted into a parallel beam 4 having an appropriate diameter by a collimator 3 and then deflected by the small mirrors 5 and 6 so that the multifaceted rotating mirror 30 can be rotated. The incident light beam 7 travels in a substantially horizontal direction.

The incident light beam 7 passes through the hole 81 of the perforated lens 8 and enters the polygon mirror 30. Then, the incident light beam 7 incident on the multifaceted rotating mirror 30 is reflected by the reflecting surface 31, and is deflected in a direction determined by each reflecting surface 31 as the multifaceted rotating mirror 30 rotates.

That is, the reflected light from the horizontal scanning pattern mirror in the multifaceted rotating mirror 30 enters the horizontal scanning line mirror 32a,
The reflected light from it enters the reading window from diagonally below and exits from it, and (a-a ') on the reading window surface as shown in FIG.
Horizontal scanning pattern such as
A scanning pattern is formed as shown in FIG.

Further, the reflected light from the oblique scanning pattern mirror in the multi-sided rotating mirror 30 is symmetrical with respect to the incident light beam 7 and has a set of two oblique scanning line mirrors 32b whose ends are coupled to each other.
Is incident on the reading window from obliquely below, then exits from the reading window, and (bb ′) at the reading window surface,
(C-c '), (b'-b ") on the vertical plane, (c'-
An oblique scan pattern is formed as shown in FIG.

On the other hand, the vertical scanning pattern mirror in the multi-sided rotating mirror 30 is a reflecting surface inclined downward and outward with respect to the drive shaft 33, and the reflected light is incident on the vertical scanning line mirror 32c. 2 mirrors 32c as shown
A pair, which are arranged symmetrically with respect to the incident light beam and at a distance from each other, and the reflected light thereof enters the reading window from obliquely below and then exits from the reading window. And the sixth on the reading window surface
The scanning lines intersect with each other as shown in (e-e ') and (d-d') in the figure, but are vertical planes perpendicular to the reading window plane.
On 24 ', vertical scanning lines such as (d'-d ") and (e'-e") are formed.

As described above, in the present invention, the polygon mirror and the horizontal, diagonal and vertical scanning line mirrors are arranged obliquely outside the lower part of the reading window, and the reflected light from the scanning line mirror enters the reading window obliquely from below. , The scanning pattern is formed not only on the reading window surface but also on the vertical surface, and since the rotation axis of the multi-faced rotary mirror is inclined, the vertical scanning pattern is formed on the vertical surface, so that the bar code is Even if this bar code is attached to the side of the product and is moved vertically to the reading window, all the scanning patterns including the vertical scanning pattern formed on the vertical surface can be surely read. You can

These scanning line mirrors 32a, 32b, 32c can set the reflection angle of the reflected beam 77 by the multifaceted rotating mirror 30 horizontally or in a direction close to the horizontal direction. It is possible to project the reflected beam 77 in a desired scanning pattern directly from the reading window 21 only by the reflection of one mirror without need.

Further, since the deflection direction of the reflected beam deflected by the multi-faced rotary mirror 30 is horizontal or close to the horizontal direction for scanning as described above, the mirror is arranged horizontally.

Due to this structure, the light beam incident on the scanning line mirror group 32 and reflected by a predetermined mirror as shown in FIG. 1 is windowed twice with the same scanning pattern every time the multifaceted rotating mirror 30 rotates. It is emitted obliquely upward through the reading window 21 through the glass 20.

Then, the barcode label of the product 24 moving on the reading window 21 is scanned.

The system scattered light 25 having a light amount level corresponding to the black and white of the bar diverges from the bar code label in all directions, but a part of the system scattered light travels in the same path as that at the time of emission in the opposite direction.

That is, a part of the signal scattered light 25 returns to the inside of the scanner through the reading window 21 and the window glass 20, and further scan line mirror group.
It is reflected by 32 and reaches the polygon mirror 30.

A part of the signal scattered light 25 that reaches the multifaceted rotating mirror 30 and is reflected by the reflecting surface 31 is condensed by the perforated lens 8 on the detection surface of the detector 28.

〔The invention's effect〕

According to the present invention, since the reflected light is incident on the reading window obliquely from below depending on the mounting position of the multi-face rotation mirror and the scanning line mirror group, the scanning pattern is formed not only on the reading window surface but also on the vertical surface thereof. Since the vertical scanning pattern is also included, the degree of freedom of the barcode mounting position is increased, and the number of mirrors in the scanning line mirror group is significantly reduced. The arrangement of the scanning line mirrors adjacent to the beam has a horizontally long configuration.

For this reason, cost reduction and device thinning can be realized in combination with the reduction of the man-hours for adjusting the optical system, and a great effect is achieved economically and industrially.

[Brief description of drawings]

1 is a side view of the optical reading device of the present invention, FIG. 2 is a plan view of the optical reading device of the present invention, FIG. 3 is a side view of an optical reading device using a conventional hologram disk, and FIG. 3 is a plan view, FIG. 5 is an explanatory view showing a scanning pattern on a final stage mirror and a reading window surface of a conventional example, and FIG. 6 is a conventional example of FIG. 3 and FIGS. FIG. 7 is an explanatory view showing scanning patterns on a reading window surface and a vertical surface in the device of the present invention, and FIG. 7 is a perspective view of a conventional optical reading device using a rotating mirror. In the figure, 1 is a laser tube, 2 is a laser beam, 3 is a collimator,
4 is a parallel beam, 5 and 6 are small mirrors, 7 is an incident light beam,
8 is a perforated lens, 20 is a window glass, 21 is a reading window, 24 is a product, 25 is a signal scattered light, 28 is a detector, 30 is a multi-sided rotating mirror, 31 is a reflecting surface, 32 is a scanning line mirror, 32a Numerals 32c are respective scanning line mirrors, 33 is a rotating shaft, 34 is a motor, 77 is a reflected beam, and 81 is a hole.

Claims (1)

[Claims] 1. A multi-faceted rotating mirror, which is located under a reading window and has a plurality of scanning mirrors each having a different tilt angle, and which is rotated via a rotary shaft, from the lower side on the other side of the reading window. Is irradiated with the condensed light beam in the substantially horizontal direction, the reflected light is received by the corresponding scanning line mirrors, and the reflected light from the scanning line mirrors has different scanning patterns through the reading windows. In the optical reading device for forming the, the multi-faceted rotating mirror is arranged on the incident light beam line obliquely outside the lower part of the reading window, the rotation axis is inclined in the incident light beam direction, and the horizontal scanning pattern mirror is used as the scanning mirror.
In addition to the diagonal scan pattern mirror, the vertical scan pattern mirror is provided, and the horizontal scan line mirror receives the reflected light from the horizontal scan pattern mirror and the diagonal scan pattern mirror due to the rotation of the polygon mirror. A diagonal scanning line mirror is arranged obliquely outside the lower part of the reading window, and its reflected light is made incident on the reading window obliquely from below, and two vertical scannings in which the reflected light from the vertical direction scanning pattern mirror is made incident. The line mirror (32c) makes the incident light beams such that the respective reflected lights are made incident on the reading window at a predetermined angle from diagonally below and a vertical scanning pattern is formed on the vertical surface outside the reading window. Optics characterized by being arranged symmetrically with respect to each other and spaced apart from each other and obliquely outside the reading window between the reading window and the polygon mirror. Reader.