JPH08305787A - Polygon mirror motor - Google Patents

Abstract

PURPOSE: To omit relative positioning adjusting work for a polygon mirror body in a code generating part for generating electric signals corresponding to respective reflection faces of the polygon mirror body in a polygon mirror motor. CONSTITUTION: The polygon mirror motor to be used for a bar code reader for reading out a bar code by laser light is provided with a polygon mirror body 1 obtained by integrally molding plural reflection faces 1a, 1c formed on the side face parts of a polygon body in order to reflect laser light continously radiated in one direction to a range more than the outside size of a bar code and a code generating part 2 for generating electric signals corresponding to the reflection faces 1a, 1c, high speed rotational driving means 5, 11, 7, 9 for continuously rotating the body 1 at a high speed and a detection means for contactlessly detecting the code generation part 2 and outputting a generated electric signal to the bar code reader.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polygon mirror motor used in a bar code reader for reading a bar code by using a laser beam.

[0002]

2. Description of the Related Art Conventionally, a bar code reading device for reading a bar code using a laser beam has been widely used with the spread of POS (point of system) devices. A polygon mirror motor is used for the type installed in.

In this polygon mirror motor, laser light continuously emitted in one direction from a laser oscillator connected to a bar code reader is reflected in a range larger than the size of a bar code printed on the exterior surface of a product in advance. A typical example is a polygon mirror body having a reflection surface formed by attaching mirrors to four side surfaces of a substantially quadrangular pyramid-shaped body and continuously rotating at high speed. The one in which a laser beam continuously emitted from one direction is irradiated to a reflecting surface and reflected in a range larger than the outer dimension of the barcode is mainly put into practical use.

In this way, when the laser light is applied to the reflecting surface of the polygon mirror motor and reflected in a range larger than the outer dimension of the bar code, information on all the reflected light including the joints of the respective reflecting surfaces is obtained. After inputting to the barcode reader side, the technology of processing by software to determine which of the four reflecting surfaces the accurate reading was performed by the laser reflected light was put into practical use. There is.

However, according to this method, even diffused reflection light generated at the joints of the respective reflection surfaces is input at the same time, and therefore, a black coating that makes the joints non-reflective is applied, which is necessary. In any case, the load of software processing increases.

Therefore, in recent years, an encoder for detecting the position of each reflecting surface of the polygon mirror body, a slit plate, and the like are aligned with the reflecting surface of the polygon mirror body and then attached, so that at least the irregular reflection light There is a mainstream technique of cutting the information of (1) and determining which of the four reflective surfaces has been accurately read by the laser reflected light by software.

For this reason, a part of the polygon mirror motor provided with a code generating portion including an encoder for generating an electric signal corresponding to each reflecting surface of the polygon mirror body of the polygon mirror motor, a slit plate and the like has been put into practical use. Has been done.

[0008]

However, the code generating section composed of an encoder, a slit plate, etc. for generating an electric signal corresponding to each reflecting surface of the polygon mirror body of the polygon mirror motor is a polygon mirror body. Since it is configured separately from, the adjustment work such as actually irradiating the reflection surface with laser light and reflecting the laser light in a range larger than the outer dimension of the barcode was always required. As for the polygon mirror body, four mirrors are prepared in advance, and after being attached to each side surface of the polygon mirror body, black coating is applied to each seam to make it non-reflective. This has caused a considerable increase in cost.

Therefore, the present invention has been made in view of the above problems, and an object thereof is a code for generating an electric signal corresponding to each reflecting surface of a polygon mirror body of a polygon mirror motor. Another object of the present invention is to provide a polygon mirror motor capable of omitting the relative positioning adjustment work of the generator with respect to the polygon mirror body.

Another object of the present invention is to provide a polygon mirror motor capable of inexpensively manufacturing a polygon mirror body.

[0011]

In order to solve the above-mentioned problems and achieve the object, a polygon mirror motor of the present invention is a polygon mirror used in a bar code reading device for reading a bar code by using a laser beam. A motor,
A plurality of reflecting surfaces formed on the side surface portion of the polygonal body for reflecting the laser light continuously emitted from one direction to the range of the outer dimension of the barcode or more, and an electric signal corresponding to the reflecting surfaces are generated. A polygon mirror body integrally formed with a code generating section for rotating the polygon mirror body, a high-speed rotation driving means for continuously rotating the polygon mirror body at a high speed, and the electric signal generated by detecting the code generating section in a non-contact manner. It is characterized by comprising a detection means for outputting to a barcode reading device.

A polygon mirror motor used in a bar code reading device for reading a bar code by using a laser beam, wherein the laser beam continuously emitted from one direction is reflected within a range larger than the outer dimension of the bar code. For this purpose, a polygon mirror body is formed by resin-molding four reflecting surfaces formed on the side surface of the substantially quadrangular pyramid-shaped body and a code generating portion for generating an electric signal corresponding to the reflecting surfaces, High speed rotation driving means for continuously rotating the polygon mirror body at high speed, and detection means for outputting an electric signal generated by detecting the code generating portion in a non-contact manner to the bar code reading device. Is characterized by.

Further, the high-speed rotation driving means and the detection means are arranged on a common component mounting board.

Further, the detecting means is of a light transmitting or light reflecting type and has a notch formed in the code generating portion,
The feature is that the concave portion and the reflecting portion are detected without contact.

[0015]

With the above structure, the polygon mirror body is integrally formed with a plurality of reflecting surfaces formed on the side surfaces of the polygonal body and the code generating portions for generating the electric signals corresponding to these reflecting surfaces. The continuous rotation at a high speed is performed by the detecting means and the detecting means detects the contact portion in a non-contact manner, and the generated electric signal is output to the barcode reading device, thereby improving the efficiency of the data memory for reading the barcode. Work to enable use.

[0016]

Embodiments of the present invention will be described below. FIG. 1 is a central cross-sectional view of a polygon mirror motor which is substantially common to each embodiment. In this figure, a bush 6 is fitted and fixed as shown in the drawing at a substantially central portion of a circuit board 4 made of glass-filled epoxy resin or the like.
The shaft body 7 press-fitted into the circuit board 4 is held so as to be orthogonal to the circuit board 4. Further, the coil 5 is mounted on the circuit board 4 in the radial direction with the shaft body 7 as the center, and constitutes a stator portion that receives a power supply from an electric circuit component (not shown) to generate a rotating magnetic field. . Further, a light transmission type sensor 3 shown in the figure or a light reflection type sensor 31 described later is mounted on the circuit board 4 at a predetermined position, and is a code integrally formed with the polygon mirror body 1 described later. It is configured to detect the slit portion 2a of the generation unit 2.

On the other hand, the shaft 7 rotates at a high speed (for example, 60
(00 rpm) to support the polygon mirror body 1 so that the inner ring sides of the pair of radial ball bearings 9 are press-fitted in the upper and lower portions of the shaft body 7, and each bearing 9
The outer race side is held by the spring-equipped washer 13 and the screw 14 in a state in which the stepped portion of the through hole inside the main hub body 8 is press-fitted as illustrated. Also,
A hub body 12 is fixed to an upper end portion of the main hub body 8, and a balancer desk 17 is sandwiched with an O-ring 15 on the hub body 12 and a polingon mirror body 1 is illustrated by using screws 16. As shown in the figure, they are supported together.

A flange portion 8f is integrally formed on the main hub body 8 as shown in the figure. The roller flange 10 is fixed on the flange portion 8f, and a multi-pole magnetized circular ring is formed below the roller flange 10. The permanent magnet 11 is fixed in such a position that it faces the coil 5 to form the rotor portion of the motor.

Further, in order to reflect the laser light continuously emitted in one direction from the laser oscillator of the bar code reading device to a range larger than the outer size of the bar code, a reflecting surface is formed on the side surface portion of the substantially quadrangular pyramidal body shown in the figure. In the polygon mirror body 1 in which 1a to 1d are formed, since the inclination angles of the reflecting surfaces are not uniform, it is not possible to obtain a dynamic balance simply by assembling the respective parts as shown. Therefore, after obtaining the finished product shown in the figure, the resin is set on a dynamic balancer to identify the vibration source, and then a relatively heavy resin material is used for a part of the edge portion of the roller flange 10 and a part of the balancer desk 17. Weight balance consisting of W1 and W2
Each is adhered to ensure the balance at high speed rotation.

On the other hand, the polygon mirror 1 is formed, for example, by injection resin molding so as to be integrated with the code generating portion 2 having the slit portion 2a, and then a mirror surface is formed in an apparatus for sputtering an aluminum film. , Reflective surface 1
a to 1d are formed.

FIG. 2A is a perspective view of the appearance of FIG. 1 according to the first embodiment, and FIG.
FIG. 4 is an output waveform diagram of FIG. In this figure, when the polygon mirror 1 is rotated at a high speed in the direction of the arrow in the figure, the sensor 3 is provided with one, two, three, and four slits 2 of the cord generator 2.
When "a" passes, an electric signal that becomes "high" is obtained, and at other times, a "low" signal is obtained.

Therefore, as described above, each of the reflecting surfaces 1a ...
Since the sensor output corresponding to the start bit and the end bit can be obtained according to 1d as shown in (b), this electric signal is input to the barcode device side to reduce the load of software processing. In this way, it is possible to softly process which of the four reflecting surfaces has been accurately read by the laser reflected light.

Next, FIG. 3 (a) is a plan view of the polygon mirror motor according to the second embodiment, taken along a plane along the cord generating portion 2, and shown in FIG. 3 (b). It is an output waveform diagram from.

In the figure, the same reference numerals are given to the already described components, and the description will be omitted to describe only the different parts. The sensor 31 shown by the alternate long and short dash line in the figure is a reflection type sensor. . The outer peripheral surface of the cord generating portion 2 of the polygon mirror 1 is mirror-finished so as to reflect the output light from the sensor 31. Further, the code generating portion 2 is provided with one, two, three, and four recesses 2b at positions corresponding to the reflecting surfaces 1a to 1d, respectively. Sensor 3
When the output light from No. 1 cannot reach the normal reflection, the output waveform of the sensor 31 becomes "low",
The output waveform from the sensor 31 shown in FIG. 3B can be obtained.

The sensor output corresponding to the start bit and the end bit thus obtained is input to the bar code device side so as to reduce the load of software processing, and thus, of the four reflection surfaces. It becomes possible to perform processing by software on which surface the laser reflected light accurately read.

Finally, FIG. 4 is a schematic block diagram of a polygon mirror motor and bar code reader according to the third embodiment. In the figure, the code generating section 2 is configured to stick a reflection surface 2c printed on a belt-shaped black background.

With this configuration, while an output substantially similar to the output waveform shown in FIG. 2 (b) is obtained and sent to the main body 100, it is reflected so that it is irradiated in the range R which is the width dimension of the bar code B or more. The reflected lights L1 to L reflected by the surfaces 1a to 1d
Among the four, the accurate reading of the bar code is performed by determining which of the reflection surfaces has been normally read by the signal from the sensor 31.

The polygon mirror body described above is not limited to the above-described quadrangular pyramid, but may be formed of a triangular pyramid, a pentagonal pyramid or the like. Further, according to the above description, only the configuration in which the motor is substantially built in the polygon mirror body 1 is described, but the present invention is not limited to this, and the polygon mirror body may be directly fixed to the output shaft of the motor having a general shape.

[0029]

As described above, according to the present invention, the relative positioning adjustment work of the code generating portion for generating the electric signal corresponding to each reflecting surface of the polygon mirror body of the polygon mirror motor with respect to the polygon mirror body. It is possible to provide a polygon mirror motor that can eliminate the above.

Further, it is possible to provide a polygon mirror motor which can inexpensively manufacture a polygon mirror body.

[0031]

[Brief description of drawings]

FIG. 1 is a central cross-sectional view of a polygon mirror motor that is substantially common to each embodiment.

FIG. 2A is a perspective view of the appearance of FIG. 1 according to the first embodiment. (B) is an output waveform diagram of the sensor 3.

FIG. 3A is a plan view showing a polygonal mirror motor according to a second embodiment by breaking along a surface along a cord generating portion 2. (B) is an output waveform diagram from the sensor 31.

FIG. 4 is a schematic configuration diagram of a polygon mirror motor and a bar code reading device according to a third embodiment.

[Explanation of symbols]

 1 Polygon mirror body 2 Code generation part 3 Sensor 4 Circuit board 5 Coil 7 Shaft body 11 Permanent magnet

Claims (4)

[Claims] 1. A polygon mirror motor used in a bar code reading device for reading a bar code using a laser beam, wherein the laser beam continuously emitted from one direction is reflected within a range equal to or larger than the outer dimension of the bar code. For this purpose, a polygon mirror body in which a plurality of reflecting surfaces formed on the side surface of the polygonal body and a code generating section for generating an electric signal corresponding to the reflecting surfaces are integrally formed, and the polygon mirror body is continuous. High-speed rotation driving means for high-speed rotation, and detection means for outputting the electric signal generated by detecting the code generator in a non-contact manner to the bar code reader. Polygon mirror motor. 2. A polygon mirror motor used in a bar code reading device for reading a bar code using a laser beam, wherein the laser beam continuously emitted from one direction is reflected within a range larger than the outer dimension of the bar code. For this purpose, a polygon mirror body is formed by resin-molding four reflecting surfaces formed on the side surface of the substantially quadrangular pyramid-shaped body and a code generating portion for generating an electric signal corresponding to the reflecting surfaces, High-speed rotation driving means for continuously rotating the polygon mirror body at high speed; and detection means for outputting an electric signal generated by detecting the code generating portion in a non-contact manner to the bar code reading device. A polygon mirror motor characterized in that 3. The polygon mirror motor according to claim 2, wherein the high-speed rotation drive means and the detection means are arranged on a common substrate for mounting components. 4. The detection means is of a light transmission or light reflection type, and detects the cutout portion, the concave portion, and the reflection portion formed in the code generating portion in a non-contact manner. The polygon mirror motor according to claim 3.