JP2746977B2 - Scanning pattern forming device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Summary] In a distribution and sales department, a scanning pattern forming apparatus that can be used for a bar code reader that reads a bar code attached to a product is disclosed. An object of the present invention is to provide an inexpensive scanning pattern forming apparatus capable of forming a scanning pattern in a desired direction by using the same in combination with a scanning pattern forming apparatus. A hollow window in which holograms are arranged in a cross shape and a light transmitting region is provided, and a rotating polygon mirror having a mirror surface for reflecting a laser beam in one direction and a mirror surface for reflecting the laser beam in another direction. And the laser beam reflected in the one direction is diffracted by a hollow hologram, To form a scanning pattern, the other laser beam reflected in a direction is transmitted through straight through the light-transmitting region of the holo window, configured to respectively form a horizontal direction and the oblique direction of the scan pattern.

[Industrial applications]

The present invention relates to a scanning pattern forming device that can be used in a barcode reader that reads a barcode printed on a product in a sales and distribution department.

[Conventional technology]

Bar code readers are widely used in various departments such as supermarkets, retail stores, factories, distribution and the like. A scanning pattern forming apparatus constituting the bar code reader will be described with reference to FIG. A rotating polygon mirror 1, a three-sided reflecting mirror 2, and a bottom reflecting mirror 3 for reflecting a laser beam are arranged. The beams reflected by the rotating polygonal mirror 1, the reflecting mirrors 2, 3 are diffracted by a hologram indicated by reference numeral 4. , A scanning pattern for reading a bar code is formed.

Then, in order to manufacture the conventional hologram 4 shown in FIG. 8A, FIG. 8B, FIG. 8C, and FIG.
As shown in the figure, five types of holograms 7a are placed on three glass plates 6 as shown in FIG.
7e were formed and the respective glass plates 6 were bonded to produce the hologram 4 shown in FIG. 8 (a).

Further, the above apparatus is of a hollow window type, and a scanning pattern forming apparatus of a mirror type which forms a scanning pattern by using only a reflecting mirror has been proposed.

[Problems to be solved by the invention]

However, in the above-mentioned hollow window type bar code reader, when producing a hologram, five kinds of holograms are formed on three glass plates and adhered to each other. It has been pointed out that when one type of hologram becomes defective, other holograms are wasted, resulting in a low yield and an increase in cost.

Further, in a scanning pattern forming apparatus using a mirror system, a vertical direction (hereinafter, for convenience, “vertical”
It is difficult to form a scanning pattern in which “horizontal” and “oblique” are determined based on the reading surface, and the vertical direction refers to a direction perpendicular to the reading surface. It has been pointed out that when applied to a barcode reader, the reading rate is reduced.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an inexpensive scan pattern forming apparatus capable of forming a scan pattern in a desired direction by using a hollow window system and a mirror system together. That is the purpose.

[Means for Solving the Problems] According to the present invention, the object is to provide a hologram in which two substrates on which one kind of hologram is formed are laminated and bonded, and the holograms are arranged in a cross shape and provided with a light transmitting area A window and a rotating polygonal mirror having a mirror surface for reflecting the laser beam in one direction and a mirror surface for reflecting the laser beam in another direction, wherein the laser beam reflected in the one direction is formed by a hollow hologram. While being diffracted to form a scanning pattern in a predetermined direction, the laser beam reflected in the other direction travels straight through the light transmitting area of the hollow window and scans the laser beam reflected in the one direction. Achieved by providing a scanning pattern device characterized in that a scanning pattern whose trajectory is orthogonal and intersects a straight line drawn in a predetermined plane is formed. Is done.

Under the above configuration, in the present invention, a hologram and a mirror system are used in combination, so that a vertical scanning pattern, which is difficult to form with the mirror system, can be formed if necessary. Thus, the number of holograms and the number of substrates can be reduced as compared with the case where a scanning pattern is formed by using.

〔Example〕

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 and 2 show a glass plate 11 as a substrate on which a hologram 10 is formed. In FIG. 1, a laser beam incident on the hologram 10 from a reflector (not shown) is indicated by an arrow. 2 shows that the laser beam is diffracted at an acute angle and forms a vertical scanning pattern 12 on the left side in the figure. In FIG. 2, the laser beam incident from a reflecting mirror (not shown) is also shown. This time, the hologram 10 diffracts the beam at an obtuse angle to form a vertical scanning beam 13 on the right side in the figure.

A feature of the present invention is to form a scanning pattern in the vertical direction using the hologram shown in FIGS. 1 and 2, and to form a scanning pattern in a horizontal and diagonal direction using a mirror system. .

Next, a first embodiment of the present invention shown in FIGS. 3 and 4 will be described.

This is an embodiment using a hologram for diffracting a laser beam at an acute angle shown in FIG. 1, and shows a case of a bar code reader. As shown in the drawing, a rotating polygon mirror 15 is disposed so as to face a light source 14 for irradiating a laser beam at a distance, and a planar reflecting mirror 16 is disposed between the rotating polygon mirror 15 and three surfaces disposed in front thereof. It comprises a reflecting mirror 17, a reflecting mirror 18 installed above the rotating polygon mirror 15 facing the rotating polygon mirror 15, and a hollow window 19 installed horizontally above the reflecting mirror 18.

The hollow window 19 is formed by bonding two glass plates 11 on each of which the hologram 10 shown in FIG. 1 is formed so that the holograms 10 have a cross shape shown in FIG.

Since the bar code reader according to the present embodiment is configured as described above, a part of the laser beam emitted from the laser beam light source 14 is incident on the rotating polygon mirror 15 and reflected at a predetermined angle as indicated by a solid arrow. Thereafter, the light is reflected by the reflecting mirrors 18 and 16 and is diffracted by the hologram 10 to form a vertical scanning pattern 12 on the left side in the figure.

The other laser beam is reflected at a predetermined angle by the rotating polygon mirror 15 as shown by the dashed arrow, then reflected by the reflecting mirror 17, passes straight through the glass plate 11 without passing through the hologram 10, and moves horizontally. Each scanning pattern 12 in the direction and diagonal direction
Form H, 12C.

As described above, the reflection path of the laser beam after reflection by the rotating polygon mirror 15 is different, as shown by a broken line and a solid line in FIG. This is because the other mirror surface is configured to have an inclination angle with respect to the one mirror surface shown.

As described above, it is a feature of the present invention that the scanning pattern formation by the hollow window method indicated by the solid arrow and the scanning pattern formation by the mirror method indicated by the broken arrow are used together.

Next, in the second embodiment shown in FIGS. 5 and 6, the hologram 10 shown in FIG. 2 is used to diffract the laser beam into an obtuse angle, and the scanning pattern is turned to the side of the rotary polygon mirror 15 (in the drawing). Right direction)
FIG.

Also in this case, the laser beam emitted from the light source 14 is reflected by the rotating polygon mirror 15 at a predetermined angle, as in the above-described embodiment,
The light is reflected by the reflecting mirror 18 and the bottom reflecting mirror 16 and is diffracted by the hologram 10 as shown by a solid line arrow to form a vertical scanning pattern 13, while those shown by a broken line arrow do not pass through the hologram 10. The scanning patterns 13H and 13C in the horizontal and oblique directions are formed directly from the glass plate 11.

〔The invention's effect〕

As described above, since the scanning pattern forming apparatus according to the present invention only forms two types of holograms on two substrates, the number of manufacturing steps can be greatly reduced as compared with the conventional hollow window type scanning pattern forming apparatus.

Further, it has been difficult to form a vertical scanning pattern with a mirror-type scanning pattern forming apparatus, but it becomes easier to form a vertical scanning pattern.

As described above, according to the present invention, a scanning pattern forming apparatus that can form a scanning pattern in a desired direction at low cost can be obtained by using the hollow window method and the mirror method together.

[Brief description of the drawings]

1 and 2 are perspective views showing a hologram used in the pattern forming apparatus according to the present invention. FIGS. 3 and 4 are side and plan views showing a first embodiment of the present invention. 6, FIG. 6 is a side view and a plan view showing a second embodiment of the present invention, FIG. 7 is an explanatory view showing a configuration of a conventional scanning pattern forming apparatus, and FIG. 8 is an explanatory view showing a process of forming a conventional hologram. FIG. In the figure, 10 is a hologram, 11 is a glass plate, 12 and 13 are vertical scanning patterns, 15 is a rotary polygon mirror, and 16, 17, and 18 are reflection mirrors.

Claims (1)

(57) [Claims] 1. A hollow window comprising two substrates having one type of hologram formed thereon, which are laminated and bonded, and the holograms are arranged in an intersecting manner and provided with a light transmitting region, and a mirror surface for reflecting a laser beam in one direction. And a rotating polygonal mirror having a mirror surface for reflecting the laser beam in another direction, and the laser beam reflected in the one direction is diffracted by a hologram of a hollow window to form a scanning pattern in a predetermined direction, The laser beam reflected in the other direction travels straight through the light transmitting region of the hollow window, and the scanning trajectory of the laser beam reflected in the one direction is orthogonal to a straight line drawn in a predetermined plane, and A scanning pattern apparatus, wherein each of the scanning patterns crosses each other.