JPH03218588A - Optical symbol reader - Google Patents

Abstract

PURPOSE:To realize the simplification of the configuration of an optical system and the miniaturization and the cost reduction of a device by arranging a photoelectric detector at the convergent point of a concave mirror which reflects a light beam reflected by a fixed plane mirror and a rotary mirror and converges it to one point. CONSTITUTION:By revolving the rotary mirror 4 by a motor 5, the light beam 14 is projected to the circumferential outside as a circular scanning pattern around the center of the axis of rotation. This light beam 14 is reflected by plural sheets of the fixed plane mirrors 6 arranged in the circumference successively toward a window 12, and is projected on the bar code 11 of an article positioned on the window 12. At that time, the light beam 14 is constituted as an octagonal scanning pattern group in a horizontal direction whose size is different in accordance with the difference of distance between the window 12 and the bar code 11 by the mutual action of the rotation of the rotary mirror 4 and plural sheets of the fixed plane mirrors 6. Then, this reflected light is reflected by the fixed plane mirrors 6 through the window 12, and after being reflected by the rotary mirror 4 and the cancave mirror 3, it is con verged to the photoelectric detector 7, and is converted into an electric signal, and bar code information is read by a recognition circuit. Thus, a mechanism can be simplified.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an optical symbol reading device for reading optical symbols such as parcodes.

[Conventional technology]

FIG. 3 shows the external configuration of a conventional general optical symbol reading device. This optical symbol reader has a light source, optical deflector,
It is equipped with a fixed plane mirror, a photoelectric detector, and one recognition path, and a light beam from a light source is deflected by an optical deflector, reflected by a fixed plane mirror, and irradiated to the outside through a window 12. Then, light reflected from an optical symbol provided on the article 10, in this case a barcode 1l, is not reflected by a fixed plane mirror, but is detected by a photoelectric detector, converted into an electrical signal, and then recognized by a recognition circuit. It is composed of

In a reading operation using this optical symbol reading device, while the barcode l1 displayed on the article 10 is facing the window 12, the article 10 is moved along the article conveyance surface along the arrow 1.
light beam 14 on the barcode ll.
This is done by scanning the

[Problem to be solved by the invention]

In the conventional optical symbol reading device described above, in order to increase the barcode reading rate, it is necessary for the operator to ensure that the barcode crosses the scanning line of the light beam 14. This requires the generation of multiple scan lines from the device in multiple directions. FIG. 4 shows an example of a scanning pattern for this purpose, in which the light beam 14 is directed to windows 12 at A and B.
, C, and D, scanning is performed in various X-shaped directions, and a plurality of scans are performed in each direction.

However, configuring the device to scan the light beam 14 in various directions and in a plurality of directions,
The optical system of the device has become complicated, which is a major obstacle in reducing the size and cost of the device.

An object of the present invention is to provide an optical symbol reading device with a simplified optical system configuration.

[Means for Solving the Problems] The optical symbol reading device of the present invention includes a light source that emits a light beam, a rotating mirror that scans the light beam in a circumferential direction, and a rotating mirror arranged circumferentially around the rotating mirror. A plurality of fixed plane mirrors each reflect a light beam scanned in the circumferential direction toward the optical symbol to be read, and a light beam reflected from the surface of the optical symbol and reflected by the fixed plane mirror and the rotating mirror is reflected. It consists of a concave mirror that converges the light to a single point, and a photoelectric detector placed at the convergence point of the concave mirror.

[Effect]

According to the present invention, a plurality of square light beam scanning patterns can be formed using a rotating mirror and a plurality of fixed plane mirrors, and the light beam can reliably scan an optical symbol regardless of the direction of the optical symbol, thereby making it possible to read the optical symbol. Realize.

〔Example〕

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

FIG. 1 shows an embodiment of the optical system in the optical symbol reading device of the present invention, in which FIG. 1(a) is a plan view and FIG. 1(b) is a plan view.
is a vertical sectional view. In the figure, a reflecting mirror 2 and a concave mirror 3 are fixed to the lower part of a window 12 inside the optical symbol reading device, and are tilted at 45 degrees with respect to the vertical axis so as to face the light source 1. Directly below this reflecting mirror 2, a rotating mirror 4 made of a plane mirror is arranged, and this rotating mirror 4 is configured to be rotated around its axis by a motor 5. This rotating mirror 4 is supported in a state inclined at 45 degrees with respect to the rotation axis of the motor 5. Further, around the rotating mirror 4, a plurality of fixed plane mirrors 6, eight in this case, are arranged in a circumferential shape (octagonal shape). These fixed plane mirrors 6 are 4
Beveled at an angle greater than 5 degrees.

A photoelectric detector 7 connected to a symbol recognition circuit (not shown) is disposed at the focal point of the concave mirror 3.

According to this configuration, the light beam 14 emitted from the light source 1
is reflected by the reflecting mirror 2, and hits the rotating mirror 4 from vertically above along the center of the rotation axis of the motor 5, where it is reflected in the horizontal direction. Then, by rotating the rotary mirror 4 with the motor 5, the light beam 14 is projected outward in a circular scanning pattern centered on the rotation axis. This light beam 14 is sequentially reflected toward the window 12 by a plurality of fixed plane mirrors 6 disposed around the window 12, and is projected onto the barcode 1l of the article 10 positioned above the window 12. At this time, due to the rotation of the rotary mirror 4 and the interaction with the plurality of fixed plane mirrors 6, the light beam 14 moves in the plane direction according to the difference in distance between the window l2 and the barcode 1l, as shown in FIG. As a result, the same scanning pattern as shown in FIG. 4 can be obtained, and the bar code 11 is scanned by this scanning pattern. .

The reflected light from the barcode 11 passes through the window 12 and is reflected by the fixed plane mirror 6, further reflected by the rotating mirror 4, reflected by the concave mirror 3, and then converged by the photoelectric detector 7, where it is converted into an electrical signal. It will be done. Using this electrical signal, barcode information is read by a recognition circuit (not shown).

Therefore, with this optical system configuration, it is possible to form an X-shaped scanning pattern in the plane direction by using only a small number of plane mirrors and concave mirrors, and it is possible to read the parcode 11 regardless of its direction. It becomes possible.

[Effects of the Invention] As explained above, the present invention uses a rotating mirror that scans a light beam in the circumferential direction and a plurality of fixed plane mirrors arranged on the circumference of this rotating mirror to scan a light beam on an optical symbol. , the light beam can be easily scanned in a multigonal scanning pattern, increasing the possibility that one scanning line will reliably cross an optical symbol such as a harcode, and as a result, the optical While ensuring complete reading of symbols, the configuration of the optical system for generating the scanning pattern can be simplified, and the device can be downsized and cost reduced.

[Brief explanation of drawings]

FIG. 1 shows an embodiment of the optical symbol reading device of the present invention,
Figure (a) is a plan view, Figure (b) is a vertical cross-sectional view, Figure 2 is a diagram showing the scanning pattern of the light beam in the reading device of Figure 1, and Figure 3 is a general optical symbol reading device. FIG. 4 is a perspective view of the external appearance of the device, and FIG. 4 is a diagram showing its light beam scanning pattern. 1...Light source, 2...Reflector, 3...Concave mirror, 4...
...Rotating mirror, 5...Motor, 6...Fixed plane mirror, 7
... Charge detector, 10... Article, 11... Barcode, 12... Window, 1 3... Movement direction, l 4... Light beam. Figure ■ (a) Figure 3 Figure 10 Figure 4

Claims (1)

[Claims] 1. A light source that emits a light beam, a rotating mirror that scans the light beam in the circumferential direction, and a rotating mirror that is arranged circumferentially around the rotating mirror to read each of the light beams scanned in the circumferential direction. a plurality of fixed plane mirrors that reflect light toward the optical symbol; a concave mirror that reflects and converges the light beam reflected on the surface of the optical symbol and reflected by the fixed plane mirror and the rotating mirror; and a convergence point of the concave mirror. 1. An optical symbol reading device comprising: a photoelectric detector disposed in a photoelectric detector;