JPH04114122A - Optical scanner - Google Patents

Abstract

PURPOSE:To provide a bar code label with a free elevation angle or rotational angle by providing one or plural 2nd fixed mirrors which changes the direction of a scanning beam by further changing the reflection direction of the projection beam of a light source from 1st fixed mirrors. CONSTITUTION:The light beam from the light source 1 is made incident on a single-surface rotary mirror 2 and the reflected light from the rotary mirror 2 is reflected toward the 1st fixed mirrors 3a-3k which are arranged concentrically as the rotary mirror 2 rotates. The 2nd fixed mirrors 4c which change the scanning direction are provided corresponding to some of the 1st fixed mirrors 3a-3k. Therefore, the reflected light from the 2nd fixed mirror group 4c comes to a scanning beam 7 which is rotated by nearly 90 deg. from the original beam 6. Further, the scanning beam is reflected by the bar code label to come to scattered light, which is reflected by a holed reflecting mirror 10 having a hole so as to pass only the beam from the light source 1, so that the light is photodetected by a photodetection sensor 12 through a condenser lens 11. Consequently, the light is provided with a rotational angle in an optional scanning direction, not to mention the scanning direction rotated by nearly 90 deg. from the scanning direction.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an optical scanning device, and more particularly to a scanning device using a laser beam for a barcode reader.

[Conventional technology]

As shown in FIG. 2, this type of conventional optical scanning device has a fixed mirror group 102 arranged around the rotation axis of a rotating reflecting mirror 101, and rotates and reflects a light beam from a light source 100 through an optical system. A light beam that is incident on the mirror 101 along the rotational axis and reflected from the rotating reflecting mirror 101 is sequentially projected onto the fixed mirror group 102, and a scanning beam 110 of the reflected light is transmitted to the price tag reading unit 106 provided on the reference plane 105. (For example, Japanese Patent Application No. 49-25422).

In this conventional optical scanning device, the scanning beam 110 has an average radiation direction set approximately in the normal direction of the window of the reference plane 105. Therefore, in this optical scanning device, when reading a barcode label 120, for example, the best method is to flow the label 120 across the beam 110 in order to reliably capture the reflected light.

[Problem to be solved by the invention]

This conventional optical scanning device uses, for example, a POS (Point
When trying to apply this method to a point-of-sale information management system, there were the following drawbacks.

In other words, as shown in Figure 3, the product is PO8 optical scanning device 3
00 reading surface 301, the barcode label on the product can be read even if the label is given a free angle of attack 310 or rotation angle 311 between the parallel surface 301 and the vertical surface 303, which improves the efficiency of cash register work. Therefore, it is required.

However, in conventional optical scanning devices, even if the scanning optical system is tilted so that the average radiation direction is about 45 degrees with respect to the reading surface in the configuration shown in Figure 2, for example, if the label is in a vertical plane, the barcode symbol will not be visible. It becomes unreadable if the orientation is in a ladder-like position. This is due to the scanning pattern shown in FIG.

Figure 4(a) is a basic example in which the average radiation direction is chosen to be the normal direction of the reading surface, and Figure 4(b) is a basic example in which the average radiation direction is selected to be approximately 45° to the normal to the reading surface. The scanning pattern on the reading surface (horizontal plane) when
4(d) shows the desired scanning pattern with scanning lines 507, 50.
8 is the product, as the label on the vertical plane moves,
The interval is widened → narrowed → matched → widened again. This is sometimes called dynamic scanning, and is obtained when the normal direction of the label surface moves approximately parallel to the scanning beam radiation direction. In FIG. 4(c), even if this effect is expected for the scanning lines 505 and 506, the angle is approximately 135°, resulting in an incomplete dynamic scan. Therefore, the orientation of the barcode label 312 in FIG. Even if the data is sent to 313, it may become unreadable.

[Means to solve the problem]

The present invention includes a light source, a single-plane rotating mirror, and a plurality of first fixed mirrors arranged concentrically around the rotating mirror and for forming a scanning pattern to reflect the emitted beam of the light source as a scanning beam. In the optical scanning device, an optical scanning device is provided corresponding to one or more of the first fixed mirrors, and further reflects the reflected direction of the emitted beam of the light source from the first fixed mirror to convert the direction of the scanning beam. The present invention is characterized in that one or more second fixed mirrors are provided.

〔Example〕

Next, the present invention will be explained with reference to the drawings.

FIG. 1(a) is a perspective view of the main parts of an embodiment of the present invention. As shown in FIG. 1(a), a light beam from a light source 1 is incident on a single-sided rotating mirror 2, and as the rotating mirror 2 rotates, the light beam reflected from the rotating mirror 2 is reflected by a plurality of concentrically arranged light beams. are reflected toward the first fixed mirrors 3a to 3k. A plurality of second fixed mirrors are provided to change the scanning direction corresponding to some of the plurality of first fixed mirrors 3a to 3.

FIG. 1(a) shows a second fixed mirror 4 corresponding to the first fixed mirror 3c.
Fig. 1(b) shows the state in which the first fixed mirror 3c is installed.
FIG. 1C is a side view of the second fixed mirror 4c, and FIG. 1C is a side view showing the positional relationship between the scanning beam reflected by the second fixed mirror 4c and the reading window 9, and FIG. shows a scanning pattern 8 in the vertical plane.

The reflected lights from the second fixed mirror group 4c each become scanning beams (reflected beams from the first fixed Wi 3c).
6, resulting in a scanning beam rotated approximately 90 degrees. The angle of direction conversion of the scanning beam by the second fixed light is not limited to approximately 90 degrees, but any conversion angle can be obtained by appropriately selecting the angle formed by the fixed mirrors 3c and 4c.

However, as shown in FIG. 1(c), if the rotation axis of the fixed mirror 2 is tilted with respect to the barcode reading window 9 and the second fixed mirror is not provided, the scanning beam reflected only by the first fixed mirror will be Both the average radiation direction and the average radiation direction of the scanning beam reflected from the second fixed mirror when the second fixed mirror is provided are tilted at 45 degrees with respect to the normal direction of the reading window 9, and both pass through the reading window 9. It is designed to be emitted.

Note that a prism may be used instead of a mirror as the second fixed mirror, and FIG. 1(c) shows a state in which a second fixed mirror 5C of a prism is provided corresponding to the first fixed mirror 3c.

The scanning beam is reflected by the barcode label and becomes scattered light, and in the area where the second fixed mirror is provided, it is reflected from the second fixed mirror to the first fixed mirror, and further reflected by the rotating mirror 2, so that only the beam from the light source 1 is reflected. Perforated reflector 1 provided with a hole to pass through
0 and is received by the light receiving sensor 12 via the condensing lens 11.

〔Effect of the invention〕

As explained above, in the present invention, not only can the scanning direction be rotated by approximately 90 degrees, but also any rotation angle in the scanning direction can be provided by selecting the angle formed by the first fixed mirror and the second fixed mirror.

[Brief explanation of drawings]

FIG. 1(a) is a perspective view of one embodiment of the present invention, and FIG. 1(b) is a perspective view of an embodiment of the present invention.
) is a side view of the first fixed mirror 3c and second fixed mirror 4c shown in FIG. 1, and FIG. 1(c) shows the positional relationship between the scanning beam reflected by the second fixed mirror 4C and the reading window 9. Side view, Figure 1 (
d) is a side view of another embodiment of the invention provided with a second fixed prism mirror 5c, FIG. 1(e) is a diagram of the scanning pattern 8 in the vertical plane, and FIG. 2 is a conventional optical scanning device. and perspective view, 3rd
The figure shows the barcode reading range of a conventional optical scanning device, and FIGS. 4(a) to 4(d) show the scanning patterns of the optical scanning device. A diagram in the case of a linear direction, a diagram in the case of approximately 45 degrees to the normal direction of the reading surface, a diagram in the case of the direction of the reading surface,
FIG. 3 illustrates a desirable scanning pattern. DESCRIPTION OF SYMBOLS 1...Light source, 2...Single surface rotating mirror, 3a-3k...First fixed mirror, 4C...Second fixed mirror, 5c...Prism, 8...Vertical plane Scanning pattern, 9...reading window, 12...light receiving sensor. Patent attorney Shindai Uchihara ノ P ball q cd> ne9 now;

Claims (1)

[Scope of Claims] 1. A light source, a single-sided rotating mirror, and a plurality of first fixed sheets arranged concentrically around the rotating mirror for forming a scanning pattern that reflects the emitted beam of the light source as a scanning beam. In the optical scanning device, the mirror is provided corresponding to one or more of the first fixed mirrors, and further reflects the emitted beam of the light source in the direction of reflection of the first fixed mirror to form a scanning beam. An optical scanning device comprising one or more second fixed mirrors that change direction. 2. The optical scanning device according to claim 1, wherein the scanning direction of the scanning beam reflected by the corresponding second fixed mirror is substantially orthogonal to the scanning direction of the scanning beam reflected by the first fixed mirror. 3. The average radiation direction of the scanning beam reflected by the second fixed mirror is approximately 45° with respect to the normal direction of the reading window of the barcode label.
The optical scanning device according to claim 1 or 2. 4. Claim 1, 2 or 3, wherein the second fixed mirror is a prism.
The optical scanning device described. 5. The optical scanning device according to claim 1, 2 or 3, wherein the second fixed mirror is a reflection hologram.