JPH03215814A - Polygon mirror - Google Patents

Abstract

PURPOSE:To facilitate the exchange of reflecting mirrors by crimping the reflecting mirrors by means of pawls, thereby fixing the reflecting mirror to a polygon blank. CONSTITUTION:The polygon mirror 10 is constituted by using the polygon blank 11 as a base body and mounting the reflecting mirrors 14 on the respective side faces 12 thereof. The reflecting mirrors 14 are pried into the spacings between reference surface parts 13 and the pawls 15 along guide rails 16 from the rotating direction of the polygon mirror 10 and are pushed in until the mirrors abut against stoppers 17, by which the reflecting mirrors 14 are inserted and positioned. Workability is improved and oscillations are more effectively suppressed if the pawls 15 at two points; the upper and lower parts, on the side faces 12 of the polygon blank 11 are so formed as to be set with the feel of a click in the prescribed positions with respect to the mounting and dismounting of the reflecting mirrors 14.

Description

[Detailed Description of the Invention] [Summary] Regarding a new structure of a polygon mirror used in barcode reading devices, etc., the present invention relates to a polygon mirror that is easy to assemble and does not reduce the accuracy and flatness of the reflector's surface tilt angle. For the purpose of providing, each side of a prismatic polygon blank is used as a reference surface,
In a polygon mirror consisting of a reflecting mirror fixed to each side, the polygon blank has claws extending in opposite directions above and below each side and forming a guide rail for inserting the reflecting mirror between the polygon blank and the reference plane. and a stopper for positioning the reflecting mirror provided on the rear end edge in the rotational direction of each side surface, and the reflecting mirror is inserted into each side of the polygon blank from the front side in the rotational direction. It is held between guide rails.

[Industrial application field]

The present invention relates to a new structure of a polygon mirror used in hard code reading devices and the like.

In the distribution industry such as supermarkets, with the spread of POS (Point of Sales) systems in recent years, barcode reading devices are becoming more sophisticated and smaller.
Demand for lower prices is increasing. In a stationary barcode reading device, a laser scanning type barcode scanner is usually used, and a polygon mirror for scanning the laser beam is required as a main part thereof.

[Conventional technology]

FIG. 3 is a diagram showing the basic structure of a stationary barcode reading device RD.

The laser beam emitted from the laser tube 2 is reflected and deflected by the reflective surfaces 1a on each side of the polygon mirror 1, as shown by the solid line outward path a in the figure, and then reflected by the reflective mirror 3 and directed toward the condensing glass 4. It passes through and scans the barcode BC printed on the product's label.

The laser beam that scanned the barcode BC is reflected at the same time as scanning, passes through the condensing glass 4, and is reflected by the reflecting mirror 3 and the reflecting surface 1a of the polygon mirror 1, as shown by the return path b of the broken line in the figure. However, the photosensor 5 outputs a signal according to the barcode BC.

Here, the angle of inclination of the reflecting surface 1a of the polygon mirror 1 is slightly different for each reflecting surface 1a, and the light is reflected by each reflecting surface 1a at a slightly different angle.

Reflecting mirrors 3 are provided at positions corresponding to respective reflection angles, and laser beams scanned in various different directions are output from a condensing glass 4.In the above-mentioned Harcode reader RD, , the reflective surface 1 of the polygon mirror 1 in order to ensure that the laser beam correctly passes through the predetermined outward path a and return path b and that the diameter of the laser beam is not distorted.
It is necessary to improve the accuracy of the angle of inclination of the surface a and the flatness of the reflecting surface 1a.

In addition, since the reflected light from barcode BC is weak,
It is important to make the area of the reflective surface 1a of the polygon mirror 1 as large as possible and to make the reflectance high.
This is preferable for increasing the C reading sensitivity.

Therefore, as this type of polygon mirror 1, one in which the reflecting surface 1a is integrally formed by silver vapor deposition is not suitable in terms of reflectance and cost, and it is not suitable for each surface of a polygonal columnar polygon blank. A reflector with a reflective mirror glued to it is used.

[Problem that the invention seeks to solve]

However, conventional polygon mirrors employ a configuration in which a reflecting mirror is adhesively fixed to the side surface of a prismatic polygon blank made of synthetic resin or the like using a rubber adhesive.

For this reason, an adhesive layer is formed between each side of the polygon blank and the reflecting mirror with a thickness that cannot be ignored in view of the accuracy of the reflecting mirror.

Therefore, due to variations in the thickness of the adhesive layer on each side surface, the precision and flatness of the angle of inclination of the surface of the reflecting mirror deteriorate, resulting in a problem of poor yield of polygon mirrors. In order to minimize the variation in the thickness of the adhesive layer mentioned above, it is necessary to assemble the polygon mirror using a jig that evenly presses the entire surface of the reflecting mirror, which requires a lot of time and effort. ing.

Furthermore, since the use of such a jig may damage the surface of the reflecting mirror, it is not easy to improve the yield. SUMMARY OF THE INVENTION In view of the above-mentioned problems, an object of the present invention is to provide a polygon mirror that is easy to assemble and that does not reduce the precision of the angle of inclination and flatness of the reflecting mirror.

[Means for solving problems]

In order to solve the above-mentioned problems, in the present invention, as shown in FIG. is provided with claws that extend in opposite directions above and below each side surface and form guide rails for inserting the reflector between the reference surface section and on the rear end edge of each side surface in the rotational direction. A polygon mirror has been proposed, which has a stopper for positioning the reflecting mirror, and the reflecting mirror is inserted into each side of a polygon blank from the front side in the direction of rotation, and is held between the guide rails. Ru.

[For production]

According to the configuration of the present invention as described above, the reflecting mirror is inserted along the guide rail from the rotation direction of the polygon mirror,
Assembly is completed by simply pushing the reflector until it hits the stopper and deciding where to insert the reflector, making work extremely easy. In addition, the back surface of the reflector comes into contact with the reference plane provided on each side of the polygon blank, which automatically determines the angle of inclination of the reflector's surface, making it possible to manufacture polygon mirrors of stable quality with a high yield. I can do it.

Furthermore, since the reflecting mirror is fixed to the polygon blank by being held by claws, the reflecting mirror can be easily replaced if necessary.

〔Example〕

Examples will be described below with reference to the drawings.

FIG. 1 is a perspective view of a polygon mirror 10 according to the present invention, showing an upper base surface 18, a lower base surface 19, and five side surfaces 12a.
, 1 2 b-・-1 2 e.

This polygon mirror 10 has a polygon blank 11 as a base body as shown in the sectional view of FIG. 2, and has a reflecting mirror 14 attached to each side surface 12 of the polygon blank 11. More specifically, each side surface l2 of the polygon blank 11 is formed smoothly so as to serve as a reference surface portion 13. The reference surface portion 13 is in contact with the back surface 14a of the reflecting mirror to determine the angle of inclination of the surface of the reflecting mirror 14. A claw 15 is provided at the top and bottom of each side surface 12, and a guide rail 16 for inserting the reflector 14 from the front side in the rotational direction between the claw 15 and the reference surface portion 13.
is formed. The width of the groove of the guide rail 16 is equal to or less than the thickness of the reflecting mirror 14, and there is almost no gap.

Further, the interval between the upper and lower guide rails 16 is equal to or less than the vertical width of the reflecting mirror 14, and there is almost no gap. Further, one stopper 17 is provided at the rear end edge of each side surface 12 of the polygon blank in the rotational direction. Such a polygon blank 11 is integrally molded from a synthetic resin material by various molding methods. The reflecting mirror 14 is a glass surface having approximately the same size as the side surface 12 of the polygon blank 11, and a vapor-deposited film of, for example, aluminum is formed on the surface of the glass. Next, a method of assembling the polygon mirror 10 by attaching the reflecting mirrors 14 to each side of the polygon blank 11 described above will be described. First, the reflector 14 is inserted along the guide rail 16 from the rotating direction of the polygon mirror 10 into the gap between the reference surface part I3 and the claw I5, and the stopper 1
7 to determine the insertion position of the reflector 14. According to the polygon mirror 10 of the above-described embodiment, the reference surface portion 1 provided on each side surface 12 of the polygon blank 11
The back surface 14a of the reflecting mirror abuts on the reflecting mirror 1.
4 can be determined.

For attaching and removing the reflector 14, use the two claws 15 at the top and bottom of the side surface 12 of the polygon blank 11 on the side surface 12.
It is more preferable for workability and vibration suppression to be set in a predetermined position with a click feeling.

The reflector 14 is integrally formed with the claw 1 on the reference surface portion 13.
It is pressed down and fixed with an elastic force of 5. Further, according to the above-described embodiment, the angle of surface inclination of the reflecting mirror 14 is maintained with high precision by the claw 15 and the reference surface portion 13. Since the insertion position is determined simply by pressing against the stopper 17, assembly can be easily performed without using any special jig.

Therefore, the assembly work of the polygon mirror 10 is easy, and the time and labor required for manufacturing the polygon mirror 10 can be significantly reduced, thereby reducing manufacturing costs. Further, by automating the mounting process of the reflecting mirror J4, it is possible to automate the assembly of the polygon mirrors 10(7) & [1].

In the above-described embodiment, the polygon blank 11 has a substantially regular pentagonal prism shape, but it may be any other prism shape or a truncated polygonal pyramid, and the number of claws and the number and position of the stoppers may vary. It is not limited to the above 10.

〔Effect of the invention〕

According to the present invention, a polygon mirror that is easy to assemble, does not reduce the precision of the angle of inclination of the face of the reflector, and does not reduce the flatness of the reflector because the reference plane on the side surface indicates the back surface of the reflector is provided at a low price. It can be manufactured in

[Brief explanation of drawings]

FIG. 1 is a perspective view of a polygon mirror according to the present invention. FIG. 2 is a sectional view taken along the line AA in FIG. 1. FIG. 3 is a diagram showing the principle of a stationary barcode reading device. In the figure, 10 is a polygon mirror l1 is a polygon blank, 12 is a side surface, 13 is a reference surface part, 11 is a reflecting mirror, a is the back of the reflecting mirror, is a claw, is a guide rail, is a stopper is an upper bottom surface, is a lower bottom surface, is the shaft hole. ■ 2

Claims (1)

[Claims] A polygon mirror (10) formed by fixing each side surface (12) of a prismatic polygon blank (11) as a reference surface portion (13) and a reflecting mirror (14) fixed to each side surface (12). In the polygon blank (11), each side face (12) of the polygon blank (11) is
The reference plane portion (1
3) and a claw (15) that forms a guide rail (16) for inserting the reflector between them, and a claw (15) for positioning the reflector (14) provided at the rear end edge in the rotational direction of each side surface. It has a stopper (17), and the reflector (14) has a polygon blank (
11) A polygon mirror characterized in that it is inserted into each side surface from the front side in the direction of rotation and is held between guide rails (16).