JP4578503B2 - Polygon mirror manufacturing method - Google Patents

Description

The present invention relates to a method for manufacturing a polygon mirror, and more particularly to a method for manufacturing a balance weight attachment zone on the upper surface of a polygon mirror.

Japanese Patent Laid-Open No. 5-273488 discloses a polygon mirror motor in which an annular groove, which is a recess for attaching a balance weight, is cut and formed on the upper surface of the polygon mirror in order to suppress vibration at the time of high-speed rotation of the polygon mirror. . As the balance weight, a viscous material such as an adhesive mixed with metal powder is used, and this is adhered to the annular groove to eliminate the unbalance, thereby correcting the surface blur of the polygon mirror.
JP-A-5-273488 (FIG. 6)

However, in the process of attaching the balance weight, if the groove width of the annular groove is narrow, the work of sticking the balance weight to the groove bottom requires carefulness. When the balance weight adheres to the groove edge, the balance is left unbalanced, and the balance weight is easily peeled off by centrifugal force or wind pressure due to high-speed rotation. On the other hand, if the groove width of the annular groove is wide, the workability of sticking the balance weight to the groove bottom becomes relatively rough, but the groove bottom width is wide, so that the positioning performance is poor.
Here, although the annular groove can be a groove having a V-shaped cross section, the adhesion area is reduced, so that the balance weight is easily peeled off. Although it is conceivable to increase the adhesion area by roughening the groove bottom, it is considerably difficult to roughen the groove bottom in the annular groove because the upper surface of the polygon mirror is formed by cutting.

  Accordingly, in view of the above problems, a first object of the present invention is to provide a polygon mirror capable of facilitating the work of attaching a balance weight. A second object of the present invention is to provide a polygon mirror that can improve the peeling strength of the balance weight. A third object of the present invention is to provide a polygon mirror that does not require an additional step and is easy to manufacture.

The present invention relates to a polygon mirror having a central hole and having a lower surface as an attachment reference surface. The upper surface has a mirror-like plane on the upper surface, and a roughness peak of the mirror-like plane is included in the mirror-like plane. A polygonal mirror manufacturing method in which an annular roughness region formed by repeating deeper roughness peaks in the radial direction is formed as a cloudy surface with the naked eye, and a cutting tool is sent at a constant speed in the radial direction of the upper surface. In the middle of cutting the mirror-like plane, an annular roughness region is formed by interpolating a rapid feed period in which the feed speed of the cutting tool is made faster than a certain speed . Here, the cloudy surface is not a reflective surface that displays an image like a mirror-like plane, but a diffusely reflective surface that is non-image quality.

An annular roughness region can be identified as a cloudy surface in a mirror-like plane by the naked eye, and can therefore be used as a balance weight attachment zone. Even if this annular roughness area is in the mirror-like plane, there are no obstacles such as groove walls in the vicinity, so in effect the annular roughness area and the mirror-like surface on the inner and outer peripheral sides Since the flat surface can be handled as a flat surface, the mounting work is facilitated compared to mounting the balance weight in the annular groove. In addition, since the annular roughness region is formed by repeating the roughness peak deeper than the roughness peak of the mirror-like plane in the radial direction, the balance weight lump that adheres to this has a plurality of roughness peaks. In this state, the adhesion area is increased and the peel strength of the balance weight is remarkably improved . Furthermore, without adding a rating another process, just because it is a surface machining including the fast-forward period, it can be expected reduction in cost and easy to manufacture.

  In addition, in order to form a suitable annular | circular shaped roughness area | region, it is desirable to make the rapid feed period of the feed speed of a cutting tool into about 7 times the said fixed speed.

  The first stack annular protrusion is integrally formed on the outer peripheral side of the mirror-like plane of the upper surface, and the protrusion height of the annular roughness region is lower than the height of the first stack annular protrusion. The depth of the roughness peak in the annular roughness region may be such that it becomes a cloudy surface with the naked eye. After manufacturing the polygon mirror, the projection of the annular roughness area does not collapse between the time when another polygon mirror is stacked on the first stack annular protrusion, the polygon mirror is assembled to the motor, and the balance weight is attached. It will end.

  Since it is sufficient that the annular roughness region can be identified as a cloudy surface, the roughness peak depth may be 2 μm or more. The depth of the roughness peak can be molded up to about 100 μm, but it is desirable to form in the range of 3 μm to 25 μm. When the particle size is 3 μm or more, the cloudy surface can be easily identified, and the surface of the annular roughness region can be easily cut up to about 25 μm.

Since the lower surface of the polygon mirror is an attachment reference surface that is combined with the receiving surface, in order to prevent damage and contamination of the lower surface, it is desirable to integrally have the second annular protrusion for stacking on the lower surface.
It is desirable to form it so as to match the position directly below the first stack annular projection.

  If such a polygon mirror is used, a polygon mirror motor having a rotating disk in which the central hole is fitted and the lower surface is seated on the receiving surface can be obtained.

  In the present invention, the balance weight mounting zone is not an annular groove, but an annular roughness region formed by repeating a roughness peak deeper than the roughness peak of the mirror-like plane in the radial direction in the upper mirror-like plane. Since it is formed as a cloudy surface with the naked eye, it is possible to provide a polygon mirror that facilitates the work of attaching the balance weight and improves the peel strength of the balance weight. Moreover, it is possible to provide a polygon mirror that is easy to manufacture without requiring an additional step.

  Next, embodiments of the present invention will be described with reference to the accompanying drawings. 1 is an external perspective view showing a polygon mirror motor according to an embodiment of the present invention, FIG. 2 is a front view thereof, FIG. 3 is an external perspective view showing a polygon mirror in the polygon mirror motor, and FIG. Sectional drawing which shows the state cut | disconnected by the AA line of FIG. 5, FIG. 5 is an enlarged view of the Z section in FIG.

  The polygon mirror motor 1 of this example is mounted in an upright posture using mounting holes (not shown) of a printed wiring board 2 on which an electrolytic capacitor 2a, a connector 2b, and the like are mounted. The rotor of the polygon mirror motor 1 has a rotating disk 3 fixed to a rotating shaft (illustrated), and a polygon mirror 10 is mounted on the rotating disk 3.

  The regular hexagonal polygon mirror 10 has a central hole H that fits into the central protrusion of the rotating disk 3, and the lower surface B of the polygon mirror 10 is seated on the receiving surface 3 a of the rotating disk 3. For this reason, the lower surface B is an attachment reference surface. A central portion of the mirror pressing member 5 is sandwiched between an upper end portion T of a rotating shaft (shown) and a fixing screw 4 screwed to the upper end portion T, and a plurality of pressing springs 5a projecting from the central portion are used. The polygon mirror 10 is pressed down.

The center hole H side of the upper surface F of the polygon mirror 10 is an annular low step surface 11, which is a non-pressure contact surface to which the plurality of presser springs 5 a are pressed. On the outer peripheral side of the upper surface F, a first stacking annular protrusion 12 is integrally formed. Between the first stacking annular protrusion 12 and the annular lower step surface 11, a mirror-like flat surface (reflective surface) 14 is formed with the naked eye. An annular roughness region 16 formed by repeatedly repeating a roughness peak deeper than the roughness peak of the mirror-like plane 14 in the mirror-like plane 14 in the radial direction is a cloudy surface (a diffusely reflective surface). Is formed.
For this reason, the mirror-like plane 14 is composed of an inner peripheral side mirror-like plane 14a and an outer peripheral side mirror-like plane 14b.

  A second stacking annular protrusion 18 is integrally formed on the lower surface B of the polygon mirror 10 at a position directly below the first stacking annular protrusion 12. The outer peripheral surface of the polygon mirror 10 is a reflection surface R for reflecting the laser beam.

The thickness of the polygon mirror 10 of this example is about 2 mm, and the heights of the first stacking annular protrusion 12 and the second stacking annular protrusion 18 are both 10 μm. As shown in FIG. 5, the roughness peaks of the inner-side mirror-like plane 14a and the outer-side mirror-like plane 14b are 0.2 μm or less.
Even if these are set as the baseline L, the roughness peak of the annular roughness region 16 is about 2 μm or more, the repetition spatial wavelength of the roughness peak is about 80 μm, and 14 roughness peaks are included.

  In order to obtain the repeated roughness peak in this annular roughness region 16, the cutting tool is sent at a constant speed of 10 μm per rotation of the polygon mirror 10 in the radial direction of the upper surface F, and the mirror-like plane 14 is being cut. The annular roughness region 16 is formed by interpolating a rapid feed period in which the feed speed of the cutting tool is about 7 times faster than the above constant speed (advanced by 70 μm per rotation of the polygon mirror 10). In the rapid feed of the cutting tool, a spiral trough M is formed by vibrations of the elastic escape action and the elastic return action from the workpiece at the cutting edge. Due to the elastic escape action, it protrudes slightly higher than the base line L, the peak portion V is at a position exclusively higher than the base line L, and the annular roughness region 16 is formed to protrude upward from the mirror-like plane 14. .

  In this way, the annular roughness region 16 can be identified as a cloudy surface in the mirror-like plane 14 with the naked eye, and thus can be used as a balance weight attachment zone. Even if the annular roughness region 16 is in the mirror-like flat surface 14, there is no obstacle such as a groove wall in the vicinity thereof, and the projection is formed microscopically. Installation work is easier than attaching weights. Further, since the annular roughness region 16 is formed by repeating a roughness peak deeper than the roughness peak of the mirror-like plane 14 in the radial direction, the balance weight lump adhering thereto has a plurality of valley portions M. Is in a state of being bitten or skewered, and the adhesion area is also enlarged, so that the peel strength of the balance weight is significantly improved. In order to obtain a repeated roughness peak in the annular roughness region, it is only necessary to interpolate a rapid feed period in the cutting of the mirror-like flat surface 14, so that it is easy to manufacture and cost reduction can be expected.

  Since the projecting height of the annular roughness region 16 is lower than the height of the first stacking annular protrusion 12, another polygon mirror 10 is formed on the first stacking annular protrusion 12 after the polygon mirror 10 is manufactured. The protrusion of the annular roughness region 16 does not have to be crushed from when the polygon mirror 10 is assembled to the motor 1 until the balance weight is attached.

  In addition, since the lower surface B of the polygon mirror 10 includes the second stacking annular protrusion 18, damage and contamination of the attachment reference surface of the lower surface B can be prevented.

1 is an external perspective view showing a polygon mirror motor according to an embodiment of the present invention. It is a front view which shows the same polygon mirror motor. It is an external appearance perspective view which shows the polygon mirror in the same polygon mirror motor. It is sectional drawing which shows the state cut | disconnected by the AA line in FIG. It is an enlarged view of the Z section in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Polygon mirror motor 2 ... Printed wiring board 2a ... Electrolytic capacitor 2b ... Connector 3 ... Rotating disk 3a ... Receiving surface 4 ... Fixing screw 5 ... Mirror pressing member 5a ... Pressing spring 10 ... Polygon mirror 11 ... Annular low step surface 12 ... 1st stack annular projection 14 ... mirror-like plane 14a ... inner peripheral side mirror-like plane 14b ... outer peripheral side mirror-like plane 16 ... annular roughness region 18 ... second stack annular projection B ... lower surface F ... Upper surface H ... Center hole L ... Base line M ... Valley portion R ... Reflecting surface T ... Upper end portion V ... Mountain portion

Claims (4)

A polygon mirror having a central hole and having a lower surface as an attachment reference surface, and has a mirror-like flat surface on the upper surface, and a rough surface deeper than the roughness peak of the mirror-like flat surface in the mirror-like plane. A method of manufacturing a polygon mirror in which an annular roughness region formed by repeating a thickness peak in a radial direction is formed as a cloudy surface with the naked eye ,
In the middle of cutting the mirror-like plane by feeding the cutting tool at a constant speed in the radial direction of the upper surface, the annular roughness is inserted by inserting a rapid feed period in which the feed speed of the cutting tool is faster than the constant speed. A method of manufacturing a polygon mirror, characterized in that a region is formed. 2. The polygon mirror manufacturing method according to claim 1, wherein the polygon mirror integrally has a first stacking annular protrusion on an outer peripheral side of the mirror-like plane in the upper surface, and the annular roughness region. The protrusion height of the polygon mirror is lower than the height of the first stacking annular protrusion. 2. The method of manufacturing a polygon mirror according to claim 1, wherein the depth of the roughness peak in the annular roughness region is 3 μm or more and 25 μm or less. The polygon mirror manufacturing method as defined in any one of claims 1 to 3 , wherein a rapid feed period of the feed speed of the cutting tool is about seven times the constant speed. Production method.