JPS6039273A - Optical reader - Google Patents

Abstract

PURPOSE:To attain ease of assembling and adjustment of an optical system by providing a black target to a prescribed position where a 0-order light made incident to a hologram disc reaches. CONSTITUTION:A part of a laser light R made incident vertically to the hologram disc 9 has a property that a part of the light penetrates the disc and rectilinear propagates. The rectilinear propagating laser light is called the 0-order light and the target 12 receiving said 0-order light is set to a prescribed part of a housing 11 specified by a design. Then the optical system has only to be adjusted so that the 0-order light is made coincident with the target 12 by visual observation without using a jig or the like with high accuracy. As the target 12, anything causing a black region is used. The target 12 is made black because the amount of the 0-order light is maximum other than the 1st order light used for actual reading, the other spectrum quantity of light is too weak not to be considered and no fault is caused by only preventing the reflection of the 0-order light.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field of the Invention The present invention relates to a reading device for reading a Herco 15 printed on a medium used in a PO3 (Point Of 5ales) system, and particularly to the structure of an optical part.

(bl Technology background) Recently, with the spread of computer network systems, electronic registers and stationary readers have been used as POS terminals in department stores, supermarkets, etc. These terminals are used at payment counters. It has been installed,
An operator such as a store clerk creates a barcode, and a barcode printed on a product label or the like is read by a reader. The barcode displays the product number, product name, and product price. When the barcode is read, the prices are sequentially displayed on the display of the electronic register, and finally the total price is displayed according to the push button instruction. In addition to the register function, this terminal also functions as a data input device for an information management system that sends sales information for each product online to a computer center for sales aggregation, and performs comprehensive product management such as inventory management and purchase management. It's one wing.

tc+ Prior Art and Problems A stationary reader used in a POS system will be described below with reference to FIGS. 1 to 3 as an example. FIG. 1 is a perspective view illustrating the usage state of an optical reading device to which the present invention is applied, FIG. 2 is a side sectional view illustrating the outline of the structure of the device, and FIG. 3 is a diagram showing the laser beam incident on the hologram disk. It is a side view explaining a state.

As shown in FIG. 1, a checkout operator 1 at a supermarket moves the products 2 of Herko 1-3 (-1) one by one in the direction of the arrow ■ without stopping from basket to basket at the counter. It is necessary for the product to pass over the transparent window 5 of the reading device 4 within a predetermined dimension.Then, the light (arrow R) emitted from the reading device 4 through the transparent window 5 is transmitted to the half-light given to the product 2. (The reading device 4 is configured to scan -3 and take the reflected light as alt.

FIG. 2 shows an outline of the structure of the reading device. A laser beam J is emitted from a laser tube 6, is reflected by a mirror 7 as shown by a dotted line, and enters a hologram disk 9 which is being rotated at high speed by a motor 8. Then, the light is polarized by the diffraction phenomenon of the borocrum disk, enters the mirror 10, and is emitted from the reading device 4 through the transparent window 5. At this time, the emitted beam is swung in a plurality of predetermined directions due to the rotation of the hologram disk 9.

Since the configuration is as follows, the precision of the optical system must be extremely high. Therefore, high-precision jigs are used to assemble the optical system, and a large number of man-hours are required to assemble the optical system. Here, as shown in FIG. 3, the laser beam arrow R incident on the hologram disk is diffracted by the hologram disk 9 as shown by the dashed line, reflected by the mirror 11, and emitted as shown by the arrow a. This arrow a is called primary light and accounts for 60 to 70% of the amount of incident light (arrow R) of the laser light.

Then, reading is performed using this primary light. However, in addition to the primary light, about 3% of the light amount of the incident laser beam arrow R is emitted through the vologram disk 9 as indicated by the arrow 0 indicated by the two-dot chain line. This is called 0th order light. In addition, it separates into countless light beams, such as the 1st-order light with a weak amount of light indicated by the dotted arrow a', the 2nd-order light (arrow b), and the -2nd order light (arrow b').

Therefore, valid I/j? , light other than the light (arrow a) is unnecessary light, and the inside of the casing 11 of the reading device 4 is made black to prevent troubles caused by diffused reflection from these non-velocity points.

(dl) OBJECTS OF THE INVENTION It is an object of the present invention to provide an optical reading device that solves the above-mentioned drawbacks, allows easy assembly and adjustment of the optical system, and eliminates the need for blackening the device housing.

(e) Structure of the Invention In order to achieve the above object, in the present invention, a code or image outside the device is irradiated with Radhe light emitted from a light source inside the device using a bologram disk, and its reflection is This is an optical reading device for reading light, in which a black body region is provided at a predetermined portion where a laser beam incident on a hologram disk in the device passes straight through the hologram disk.

Embodiment of the Invention An embodiment of the present invention will be described below with reference to FIG. 4. FIG. 4 is a side view illustrating a state in which a black area according to the present invention is provided.

In the diagram, 10 is Mira and 12 is the target.

Items with the same reference numerals throughout the plan are the same.

In the present invention, we focus on the fact that a part of the laser light (arrow R) that is perpendicularly incident on the hologram disk 9 passes straight through the hologram disk 9 as zero-order light, and we use this zero-order light to This is an attempt to relatively easily assemble and adjust the optical system, which has been difficult.

That is, the most important thing in this optical reading device 4 is to emit the laser beam from the transparent window 5 in an accurate direction. For this purpose, it is an absolute condition that the laser beam (arrow R) be perpendicularly incident on a predetermined position of the hologram disk 9. In the conventional technology, there is no way to detect this, so the reflected light (arrow a) from the mirror 10 is measured, and a jig is used to determine the emission direction of the laser beam from the laser tube 6, the position of the mirror, the angle of inclination, etc. adjustments were being made.

However, since a part of the vertically incident laser light, which is called 0th order light, has the property of penetrating the bologram disk 9 and traveling straight, the housing 11 can limit the target 12 that receives this 0th order light by design. Set it in the specified section. Then, the optical system can be adjusted so that the zero-order light coincides with the target 12 visually, without using a high-precision jig or the like.

The target 12 may be, for example, black and circular with a diameter of 5 to 5 mm, and any material that produces a black area in the target 12 may be used, such as pasted with a black sole, painted black, or made of a black material such as rubber. anything is fine.

The reason why the surface target 12 is made black is that it is actually used for reading.
Other than the order light, the 0th order light has the largest amount of light, and the other spectral light amounts are weak and do not pose a problem, so 0/p? This is because if only the reflection of light is prevented by providing a black area, no trouble will occur.

Therefore, it is no longer necessary to blacken the inside of the casing 11 as in the prior art.

tel As described in detail, by providing a black target at a predetermined position where the zero-order light incident on the porogram disk reaches as in the present invention, assembly and adjustment of the optical system is facilitated, and the casing of the optical reading device is Black treatment inside the body is no longer necessary.

[Brief explanation of the drawing]

Fig. 1 is a perspective view illustrating the usage state of an optical reading device to which the present invention is applied, Fig. 2 is a side sectional view illustrating the outline of the structure of the device, and Fig. 3 is a laser beam incident on a vologram disk. FIG. 4 is a side view illustrating a state in which a black area is provided according to the present invention. In the figure, 2 is the product, 3 is the Herko F-14 reader,
5 is the store window, 6 is the laser tube, 7.10.10゛ is Mira,
9 is a bologram disk, 11 is a housing, and 12 is a target. 1st day $ 3 f 1,000 4 Figure) 7 0

Claims (1)

[Claims] An optical reading device that uses laser light emitted from a light source inside the device to illuminate a code or image outside the device using a hologram disk, and reads the reflected light. An optical reading device characterized in that a black body region is provided at a predetermined portion where the hologram disk passes straight through the hologram disk.