JP2002221684A - Method for driving and rotating rotator and air bearing device for rotator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an air bearing device for a rotator capable of stably rotating a rotator without damaging a rotary shaft. SOLUTION: This air bearing device 20 for the rotator air-supports and drives and rotates the rotator consisting of a polygon mirror constituting body 21 where a mirror surface is formed on a side surface 29, the rotary shaft 24 is inserted and fit in its center part and also an insertion barrel 27 in which a magnet ring 31 is inserted is integrally formed at its lower part, and has an air supply path constituting body 33 having an air supply path 37 for supplying air toward the inner peripheral wall of the barrel 27 and an air discharge path constituting body 34 where an air discharge port 50 communicating with the path 37, facing to the inner peripheral wall of the barrel 27 and discharging the air toward the inner peripheral wall in order to rotate the rotator in a fixed direction while supporting the rotator is formed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is used for testing the performance of a rotor used as an optical deflector (polygon mirror scanner) for an image forming apparatus such as a copying machine, a printer, a facsimile machine, and an image reading apparatus. The present invention relates to an improvement in a rotor bearing device to be used.

[0002]

2. Description of the Related Art Hitherto, there has been known a polygon mirror structure 1 which constitutes a part of the polygon mirror scanner shown in FIG. In FIG. 1, reference numeral 2 denotes a polygon mirror plate, and reference numeral 3 denotes a cylindrical body as an insertion cylinder into which a ring-shaped multipolar magnet described later is inserted.

The polygon mirror plate 2 has a circular fitting hole 2a formed in the center thereof, and a mirror surface formed on a side surface 2b. The cylindrical body 3 has a circular fitting protrusion 3a formed at the center thereof to be fitted into the fitting hole 2a. The upper surface of the cylindrical body 3 is a reference mounting surface 3b for the polygon mirror plate 2. A shaft hole 3c into which the rotating shaft 4 is press-fitted is formed at the center of the fitting protrusion 3a.

A ring-shaped multipolar magnet 5 is fitted in the cylinder of the cylindrical body 3. The polygon mirror plate 2 presses the rotation shaft 4 into the shaft hole 3 c of the cylindrical body 3,
The retaining ring 7 is attached to the cylindrical body 3, thereby forming a rotor as the polygon mirror constituting body 1.

[0005] A winding coil (not shown) constituting a part of the stator is disposed on the multipole magnet 4 so as to be opposed from the inner peripheral side. The motor is driven to rotate, and a driving motor is roughly constituted by the winding coil and the multipole magnet 4.

In this type of rotor, if the surface accuracy of the mounting reference surface 3b of the cylindrical body 3 is not good, when the polygon mirror plate 2 is assembled to the cylindrical body 3, the polygon mirror plate 2
Is distorted and the side surface 2b functioning as a mirror surface of the polygon mirror plate 2 is distorted and its optical characteristics are degraded. The side surface functioning as a mirror surface when the polygon mirror assembly 1 is rotationally driven. The dynamic surface tilt of 2b occurs, the optical characteristics thereof deteriorate, and the image quality deteriorates.

For example, as shown in FIG. 2, if the surface inclination angle δ between the side surface 2b functioning as a mirror surface and the mounting reference surface 3b is not within the design standard, as shown in FIG. When writing is performed, there is a problem that the line spacing L becomes uneven.

Therefore, conventionally, before assembling the polygon mirror plate 2 to the cylindrical body 3, the rotary shaft 4 is press-fitted into the cylindrical body 3 in order to inspect the surface accuracy of the mounting reference surface 3b of the cylindrical body 3 in advance. To form a rotor 1A shown in FIG.
A is rotated, and the mounting reference surface 3b is used as a measurement surface of the rotor 1A to inspect the runout characteristics of the measurement surface.

FIG. 4 is a plan view showing a bearing device 8A used for inspecting the surface runout characteristics of the cylindrical body 3 of the rotor 1A.

In the bearing device 8A, a pair of upright walls 10, 10 are formed on a base 9. Bearing walls 11, 11 for supporting the rotor 1 </ b> A are provided on the pair of upright walls 10, 10. One of the bearing walls 11, 11 is slidable in the direction of the arrow XX along the guide shafts 12, 12.

On the upper surfaces of the bearing walls 11, 11, V-shaped grooves 13, 13 are formed with high precision. After press-fitting the rotary shaft 4 into the cylindrical body 3, the V-shaped groove portions 1 of the pair of bearing walls 11, 11 are formed.
It is rotatably supported on 3 and 13.

When measuring the surface run-out, for example, the sensor portion 14A of the capacitance type measuring probe 14 is placed on the mounting reference surface 3b, and the cylindrical body 3 of the rotor 1A is placed on the cylindrical body 3 by hand. 3 is turned by hand, and the surface deflection is measured by a change in the detection output of the measurement probe 14.

[0013]

However, in the conventional bearing device, since the rotor 1A is rotated by hand, the rotation may be unstable, resulting in a variation in measurement accuracy.

Further, since the rotation shaft 4 is supported by the V-shaped grooves 13 and 13 to perform the measurement while rotating, the rotation shaft 4 may be damaged during the measurement.

In particular, as shown in FIG. 5, in the case of a rotor 1A in which the polygon mirror plate 2 and the cylindrical body 3 are formed of an integral polygon mirror structure 1, the center of gravity is shifted from the center in the axial direction. , The rotation of the rotor 1A is likely to be unstable.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a method of driving a rotor to rotate stably without damaging a rotating shaft, and a method of rotating the rotor. An object of the present invention is to provide an air bearing device for a rotor.

[0017]

According to a first aspect of the present invention, there is provided a method for rotating a rotor, the method comprising: rotating a rotor having a rotary shaft mounted on a cylindrical body by air; After floating by air pressure, air is blown onto the inner peripheral wall of the cylindrical body to rotate the rotor.

According to a second aspect of the present invention, there is provided a rotation driving method for a rotor, wherein a mounting surface is formed integrally with a mirror surface formed on a side surface, a rotation shaft being inserted at a center portion, and a magnet ring being inserted at a lower portion. A rotating drive method of rotating while supporting a rotor composed of a polygon mirror structure by air, after floating by air pressure of the rotating shaft, blowing air to the inner peripheral wall of the insertion cylinder, The rotor is driven to rotate.

An air bearing device for a rotor according to claim 3 is an air bearing device for rotating a rotor having a rotary shaft mounted on a cylindrical body by air, wherein the air bearing device includes a cylindrical member. An air supply path structure having an air supply path for supplying air toward the peripheral wall, and in a certain direction while supporting the rotor facing the inner peripheral wall of the cylindrical body and communicating with the air supply path. And an air discharge path structure having an air discharge port for discharging air toward the inner peripheral wall for rotation.

According to a fourth aspect of the present invention, the air bearing device for a rotor has a column-shaped thrust bearing in which the air supply path structure faces the lower end of the rotary shaft and supports the rotary shaft so as to be rotatable in the axial direction. It is characterized by the following.

According to a fifth aspect of the present invention, in the rotor air bearing device, the column-shaped thrust bearing is made of a material having a large number of pores, and air is supplied to the lower end of the rotating shaft through the porous material. And

According to a sixth aspect of the present invention, in the rotor air bearing device, the column-shaped thrust bearing has a curved surface corresponding to a lower end of the rotary shaft, the upper end facing the lower end of the rotary shaft. Features.

According to a seventh aspect of the present invention, in the air bearing device for a rotor, the air discharge path structure is provided with a cylindrical radial bearing that rotatably supports the rotating shaft in a radial direction. And

The air bearing device for a rotor according to claim 8, wherein the cylindrical radial bearing is made of a material having a large number of porous materials, and air is supplied to the peripheral surface of the rotary shaft through the porous materials. Features.

According to a ninth aspect of the present invention, in the rotor air bearing device, the air discharge path constituting member has a cylindrical air pressure holding member for holding air pressure therein, and the cylindrical radial bearing is formed of the cylindrical air bearing. It is characterized by being provided on the air pressure holding body.

According to a tenth aspect of the present invention, in the air bearing device for a rotor, a cylindrical setting portion for setting the cylindrical air pressure holding member is formed in the air discharge path constituting body, and the air discharge port is provided with the air discharge port. It is formed on the peripheral wall of the cylindrical setting portion at a predetermined interval in the circumferential direction thereof, and between the cylindrical air pressure holding member and the cylindrical setting portion, the inside of the cylindrical air pressure holding member and the air discharge are formed. An air communication passage communicating with the outlet is formed.

12. The air bearing device for a rotor according to claim 11, wherein the air supply path structure includes a branch passage for thrust bearing, wherein the air supply path supplies air toward the cylindrical thrust bearing. And a branch passage for holding air pressure for supplying air to the inside of the air pressure holding body.

According to a twelfth aspect of the present invention, in the rotor air bearing device, the air is supplied from the thrust bearing branch passage to the lower end portion of the rotary shaft via the cylindrical thrust bearing porous. The air is supplied to the peripheral surface of the rotary shaft from the branch passage for holding air pressure via the porous portion of the cylindrical radial bearing.

According to a thirteenth aspect of the present invention, a part of the air supplied to the inside of the cylindrical air pressure holding member is guided along the axial direction through the porous portion of the cylindrical radial bearing. Thus, the rotor is supplied to the inside of the tubular body, and the rotor is levitated.

According to a fourteenth aspect of the present invention, there is provided an air bearing device for a rotor, wherein the cylindrical body is provided with a polygon mirror structure having a mirror surface on a side surface and a ring-shaped magnet mounted on an inner peripheral wall thereof. It is a sleeve.

According to a fifteenth aspect of the present invention, there is provided an air bearing device for a rotor, in which a mounting cylinder having a mirror surface formed on a side surface, a rotary shaft inserted into a central portion, and a magnet ring inserted into a lower portion is integrally formed. An air bearing device for a rotor that rotates while supporting a rotor composed of a polygon mirror assembly with air, and has an air supply path for supplying air toward an inner peripheral wall of the insertion tube. An air supply path component, and air that is communicated with the air supply path and discharges air toward the inner peripheral wall to rotate in a certain direction while supporting the rotor while facing the inner peripheral wall of the insertion tube. And an air discharge path structure having a discharge port formed therein.

The air bearing device for a rotor according to claim 16 has a columnar thrust bearing in which the air supply path structure faces the lower end of the rotating shaft and supports the rotating shaft so as to be rotatable in the axial direction. The air bearing device for a rotor according to claim 15, wherein:

[0033] The air bearing device for a rotor according to claim 17, wherein the columnar thrust bearing is made of a material having a large number of porous materials, and air is supplied to the lower end of the rotating shaft through the porous materials. And

An air bearing device for a rotor according to claim 18, wherein the columnar thrust bearing has a curved upper surface facing the lower end of the rotating shaft, the upper end facing the lower end of the rotating shaft. .

The air bearing device for a rotor according to the nineteenth aspect is characterized in that the air discharge path member is provided with a cylindrical radial bearing that supports the rotating shaft so as to be rotatable in a radial direction. And

According to a twentieth aspect of the present invention, in the rotor air bearing device, the cylindrical radial bearing is made of a material having a large number of porous materials, and air is supplied to the peripheral surface of the rotary shaft through the porous materials. Features.

22. The air bearing device for a rotor according to claim 21, wherein the air discharge path constituting member has a cylindrical air pressure holding member for holding air pressure therein, and the cylindrical radial bearing is formed of the cylindrical air bearing. It is characterized by being provided on the air pressure holding body.

[0038] In the air bearing device for a rotor according to claim 22, the air discharge path constituting body is formed with a cylindrical set portion in which the cylindrical air pressure holding member is set, and the air discharge port is formed. The cylindrical wall portion of the cylindrical set portion is formed at a predetermined interval in the circumferential direction thereof, between the cylindrical air pressure holder and the cylindrical set portion, the inside of the cylindrical air pressure holder and the air An air communication passage communicating with the discharge port is formed.

24. The air bearing device for a rotor according to claim 23, wherein the air supply path constituting member includes a thrust bearing branch passage for supplying air toward the cylindrical thrust bearing and the thrust bearing branch path. And a branch passage for holding air pressure for supplying air to the inside of the air pressure holding body.

The air bearing device for a rotor according to claim 24, wherein the air is supplied from the thrust bearing branch passage to the lower end portion of the rotating shaft via the porous portion of the cylindrical thrust bearing. The air is supplied to the peripheral surface of the rotating shaft from the branch passage for holding air pressure via the porous portion of the cylindrical radial bearing.

In the air bearing device for a rotor according to the twenty-fifth aspect, a part of the air supplied to the inside of the cylindrical air pressure holding member is guided along the axial direction through the porous portion of the cylindrical radial bearing. Thus, the rotor is supplied to the inside of the insertion tube and levitated.

In the air bearing device for a rotor according to the twenty-sixth aspect, an insertion cylinder in which a mirror surface is formed on a side surface, a rotation shaft is mounted on a central portion, and a magnet ring is mounted on a lower portion is integrally formed. An air bearing device for a rotor that rotates while supporting a rotor composed of a polygon mirror structure with air, and has an air supply path for supplying air toward an inner peripheral wall of the insertion tube. A path component, and an air discharge path communicating with the air supply path and discharging air toward the inner peripheral wall to rotate in a certain direction while supporting the rotor facing the inner peripheral wall of the insertion tube. And a column-shaped thrust bearing having a large number of porous bodies and supporting the rotating shaft so as to be rotatable in the axial direction facing the lower end of the rotating shaft. Vignetting, the air discharge path structure has a tubular air pressure holder for holding the air pressure therein,
The air pressure holding body is provided with a cylindrical radial bearing having a large number of porous bodies and rotatably supporting the rotating shaft in a radial direction, and the air pressure holding body is set in the air discharge path structure. A cylindrical set part is formed,
The air outlet is formed on the peripheral wall of the cylindrical setting portion at a predetermined interval in a circumferential direction thereof, and the cylindrical air pressure holding member is provided between the cylindrical air pressure holding member and the cylindrical setting portion. An air communication passage communicating between the inside of the thrust bearing and the air discharge port is formed, and the air supply passage structure includes a branch passage for a thrust bearing in which the air supply passage supplies air toward the cylindrical thrust bearing. And an air pressure holding branch passage for supplying air into the cylindrical air pressure holding body.

In the air bearing device for a rotor according to the twenty-seventh aspect, a part of the air supplied to the inside of the cylindrical air pressure holding member is guided along the axial direction through the porous portion of the cylindrical radial bearing. Thus, the rotor is supplied to the inside of the insertion tube and levitated.

According to the invention of the air bearing device according to the first and second aspects of the invention, the method of rotating the rotor after floating the rotating shaft is used. Can be prevented from being damaged.

According to the third, fourth, fifteenth, and sixteenth aspects of the invention, the rotor can be rotated while being supported by air, so that damage to the rotating shaft can be prevented.

According to the fifth and seventeenth aspects of the present invention, the columnar thrust bearing is formed of a material having a large number of pores, and air is supplied to the lower end of the rotary shaft through the porous material to lift the rotary shaft. With this configuration, the rotating shaft can be reliably levitated.

According to the sixth and eighteenth aspects of the present invention, since the upper end of the columnar thrust bearing facing the lower end of the rotary shaft has a curved surface corresponding to the shape of the lower end of the rotary shaft. The rotating shaft can be stably levitated.

According to the seventh and nineteenth aspects of the present invention, since the cylindrical radial bearing for supporting the rotary shaft rotatably in the radial direction is provided, the rotary shaft can be stably rotated. It is possible.

According to the eighth and twentieth aspects of the present invention, since the cylindrical radial bearing is made of a material having a large number of porous bodies, air is blown to the peripheral surface of the rotary shaft to be rotatable by the air. The shaft can be rotatably supported, so that it is possible to reliably prevent the peripheral surface of the rotation shaft from being damaged, and to further stably rotate the rotation shaft.

According to the ninth and twenty-first aspects of the present invention, since the cylindrical radial bearing is provided on the air pressure holding body for holding the air pressure therein, the air pressure is supplied to the rotary shaft via the porous material. Air stabilization.

According to the tenth and twenty-second aspects of the invention, the air stabilized by the cylindrical air pressure holding member is supplied to the rotor from the air discharge port, so that the rotor can be rotated more stably. It is possible to do.

According to the present invention, air from the same air supply source can be supplied to the cylindrical thrust bearing and the cylindrical air pressure holder. is there.

According to the thirteenth and twenty-fifth aspects of the invention, the air guided along the axial direction via the porous portion of the cylindrical radial bearing contributes to the floating of the rotor. The levitation force can be obtained stably.

According to the twenty-sixth aspect of the present invention, the rotor can be rotated after the rotor is levitated, and the rotating shaft is levitated by air while the rotor is rotating. Since the peripheral surface is protected by the air layer, damage to the rotating shaft can be prevented.

Further, since the air stabilized by the cylindrical air pressure holding member is supplied to the rotor from the air discharge port, the rotor can be rotated stably.

Further, since a cylindrical thrust bearing and a cylindrical radial bearing are provided and air is supplied to the rotating shaft through the porous member, the rotation of the rotating shaft can be stabilized.

According to the twenty-seventh aspect, the air guided in the axial direction through the porosity of the cylindrical radial bearing contributes to the floating force of the rotor, so that the floating force can be stably obtained. .

[0058]

FIG. 6 is a sectional view showing the entire structure of an air bearing device for a rotor according to the present invention.

In FIG. 6, reference numeral 20 denotes an air bearing device, and reference numeral 21 denotes a polygon mirror structure. The polygon mirror structure 21 has a polygon mirror plate 22 as shown in FIG. A columnar fitting projection 23 is formed on the upper surface of the center of the polygon mirror plate 22. A shaft hole 25 into which the rotating shaft 24 is press-fitted is formed in the columnar fitting protrusion 23. The polygon mirror plate 22
An annular groove 26 for balancing rotation is formed in the peripheral portion of.

On the lower surface of the polygon mirror plate 22,
A thin-walled insertion tube 27 into which a multipolar magnet as a magnet ring described later is inserted is formed. At the lower end of the insertion tube 27, an annular flange 28 for balancing rotation is formed. The side surface 29 of the polygon mirror plate 22 is a mirror surface.

A multipolar magnet 31 is loosely fitted and inserted into the inner peripheral wall 30 of the insertion tube 27. After the insertion, the multipolar magnet 31 is fixed to the insertion tube 27 with an adhesive.

In the polygon mirror structure 21, the lower end surface 32 of the insertion tube 27 is used as a measurement surface for measuring the surface runout characteristic during rotation of the rotor 1A. The polygon mirror assembly 21 has the multipole magnet 31
Before fixing to 7, the surface runout characteristics are measured. Here, “′” is added to the meaning that the multipolar magnet 31 is not inserted into the rotor 1A.

The air bearing device 20 has an air supply channel component 33 and an air discharge channel component 34. As shown in FIG. 8, the air supply path constituting body 33 is
And a mounting plate portion 36. Base part 3
5 has an air supply passage 37 formed at the center thereof.
The air supply path 37 is connected to an air supply source (not shown).

The mounting plate 36 has a positioning annular groove 38 for positioning the air discharge path constituting member 34.
Are formed, and a fastening hole 39 is formed. A fitting hole 40 into which a thrust bearing described later is fitted is formed on the upper surface of the base portion 35, and the fitting hole 40 is connected to the air supply passage 37 through a passage 41 serving as a branch passage for a thrust bearing. I understand.

The base 35 has an air supply passage 37
Is formed with an air discharge passage 42 communicating with. A passage 44 communicating with the inside of a cylindrical air pressure holding body 43 as an air pressure holding branch passage is formed in the air discharge passage 42.

As shown in FIG. 9, the air discharge path constituting member 34 has an attached plate portion 45. A fastening hole 46 is formed in the attached plate portion 45 at a position corresponding to the fastening hole 39. The attached plate portion 45 has a cylindrical set portion 47 for setting the cylindrical air pressure holding member 43 formed on the upper surface thereof, and the lower surface thereof is fitted in the positioning annular groove 38 to form the air discharge path constituting member 34. Annular projection 48 for positioning
Are formed. The air discharge path component 34 is fastened and fixed to the air supply path component 34 by a fastening screw (not shown).

At the upper end of the cylindrical setting portion 47, a cylindrical air pressure holding member 43 is attached to the base portion 34 of the air supply path constituting member 33.
An annular inner flange portion 49 that presses toward the inner surface is formed. An air outlet 50 for discharging air at predetermined intervals in the circumferential direction is formed in the peripheral wall of the cylindrical set portion 47. This air outlet 50 is shown in FIG.
As shown in FIG.
The air is discharged toward the inner peripheral wall 30 in a direction substantially along the wall surface.

As shown in FIG. 11, the cylindrical air pressure holding body 43 has a fitting step 5 into which the cylindrical radial bearing 51 is fitted.
2, and a passage 53 facing the passage 44 for supplying air to the inside of the cylindrical air pressure holding member 43 is formed. Annular flanges 54 and 55 are formed at the lower end and the upper end of the cylindrical air pressure holder 43. The inner peripheral wall of the cylindrical set portion 47 and the outer peripheral walls of the annular flange portions 54 and 55 are fixed with an adhesive.

The fitting step 52 has a small diameter fitting hole 56 and a large diameter fitting hole 57 formed therein. Cylindrical radial bearing 51
As shown in an enlarged view in FIG.
8 is set. The small-diameter portion 58 is fitted in the small-diameter fitting hole 56, and the large-diameter portion 59 is fitted in the large-diameter fitting hole 57, and is fixed inside the cylindrical air pressure holding body 43 by bonding with an adhesive. Is done. The lower end of the cylindrical radial bearing 51 is also fitted in the large-diameter fitting hole 57 'and is fixed by an adhesive. As a result, it is possible to prevent unintended air leakage in design.

The cylindrical radial bearing 51 is made of a material (sintered body) having a large number of porous layers 60. The cylindrical radial bearing 51 has an insertion hole 6 extending in the axial direction.
One.

A thrust bearing 62 having a shape shown in an enlarged manner in FIG. 13 is fitted in the fitting hole 40 of the base portion 35. The upper end of the thrust bearing 62 is a curved surface 63 corresponding to the shape of the lower end of the rotary shaft 24.
4 (sintered body).

The rotating shaft 24 of the rotor 1A 'is inserted into the insertion hole 61 of the cylindrical radial bearing 51, and is rotatably supported by the cylindrical radial bearing 51. Thrust bearing 6
The curved surface 63 plays the role of supporting the rotating shaft 24 rotatably in the axial direction with the curved surface 63 facing the lower end portion 24A of the rotating shaft 24.

As shown in FIG. 14, distribution grooves 66 are formed in the bottom wall 65 and the peripheral wall of the annular flange 55 in the cylindrical air pressure holder 43. Outer peripheral wall 43a of cylindrical air pressure holder 43 and inner peripheral wall 47a of cylindrical set portion 47
A gap 67 is formed between the air passage and the air outlet 50. The gap 67 is an air communication passage that communicates the inside of the cylindrical air pressure holder 43 with the air discharge port 50.

The lower end surface 32 of the insertion tube 27 is
The sensor portion of the capacitance type measurement probe 68 shown in FIG. 1 is exposed, and the surface runout characteristic of the rotor 1A is measured by a change in the detection output of the measurement probe 68 during rotation of the rotor 1A. As shown in FIG. 7, a mark "." 28A indicating the reference position in the rotation direction is attached to the peripheral wall 28B of the annular flange portion 55 of the insertion tube 27.

The measuring probe 65 is connected via a probe holder 71 to a measuring device main body 70 installed on a base plate 69 shown in FIG. The measuring device body 70
Is configured to reciprocate in the Z-axis direction, and 70A is a handle of the measuring device main body 70. A fitting hole 72 is formed in the base plate 69, and the air bearing device 20
Is set on the base plate 69 by fitting the base portion 35 into the fitting hole 72.

A part of the air supplied from the air supply source is supplied to the air supply passage 37 and the passage 41 as shown by an arrow A in FIG.
Is supplied to the thrust bearing 62 as shown by the arrow B, and is supplied to the lower end portion 24A of the rotating shaft 24 through the porous 64 of the thrust bearing 62, so that a floating force is applied to the rotating shaft 24. The air is uniformly supplied to the lower end of the rotating shaft 24 by the porous portion 64.

The remaining air flows toward the air discharge path 42 as shown by the arrow C, a part of the air is discharged to the outside as shown by the arrow D, and the remaining air passes through the passage 44 as shown by the arrow E. Is led to the inside of the air pressure holding body 43.

The pressure inside the air pressure holder 43 is increased by the air supplied through the passages 42 and 44. The air supplied to the inside is supplied to the peripheral surface of the rotary shaft 24 as shown by an arrow F through a number of porous members 60 interposed in the radial direction of the cylindrical radial bearing 51, and the rotary shaft 24 is rotatably held by air pressure. Is done. This porous 6
By 0, air is evenly supplied to the peripheral surface of the rotating shaft 24.

A part of the air supplied to the cylindrical radial bearing 51 is guided to the inside of the insertion cylinder 27 as shown by an arrow G through a number of porous members 60 interposed in the axial direction, thereby rotating. A levitation force is given to the child 1A '.

The internal pressure of the cylindrical air pressure holding member 43 reaches a substantially stable state by the supply of air, and the air in the cylindrical air pressure holding member 43 passes through the distribution groove 66 to be in a gap as shown by an arrow H. Guided to 67. Accordingly, the pressure difference between the internal pressure of the gap 67 and the external pressure (atmospheric pressure) increases, and the amount of air discharged from the air discharge port 50 increases as indicated by the arrow I. Thereby, the rotor 1A '
Starts low-speed rotation.

Thereafter, the measuring apparatus main body 70 is moved in the Z-axis direction by turning the handle 70A shown in FIG. Then, when the start button (not shown) is pressed when the mark “·” 28A passes right above the measurement probe 68, the measurement of the surface runout characteristic is executed. The detection output is amplified by an amplifier 73 shown in FIG. 16, then converted into a digital signal by an analog-to-digital converter 74 and input to a shake calculating device 75.

The shake calculating device 75 sets the mark “•” 2
Assuming that the position of 8A is the angle “0 °”, as shown in the angle development diagram of FIG. 17, the maximum shake amount Y _max , the minimum shake amount Y _min , the angular position θ1 of the maximum shake amount Y _max , and the angle of the minimum shake amount Y _min The position θ2 is obtained. The angular position θ1 of the maximum shake amount and the angular position θ2 of the minimum shake amount are shifted by 180 degrees in principle.

As shown in FIG. 18, when the polygon mirror plate portion 22 is inclined with respect to the rotation shaft 24, an inclination angle δ 'occurs between the rotation shaft 24 and the side surface 29.

This inclination angle δ ′ is determined by the polygon mirror plate 2
Since the diameter φ of the second lower end face 30 is known, it can be calculated by obtaining the inclination angle θ'and a diameter φ of maximum deflection amount Y difference between the _max and the minimum deflection amount Y _min and the polygon mirror plate portion 22 .

After calculating the tilt angle θ ′, the deflection angle calculating device 75 calculates the angle δ ′ formed by the side surface 29 with respect to the rotating shaft 24 from the tilt angle θ ′, and calculates the cutting amount for each predetermined angle. I do.

The result of the calculation of the cutting amount is input to a control device 77 constituting a part of a processing device 76 for mirror-finishing the side surface 29 of the polygon mirror plate portion 22. The mirror processing device 76 includes an angle indexing plate 78 and a setting mechanism 79 as shown in FIG. The setting mechanism 79 includes a setting jig 80 and an annular column mounting plate 81.

The angle indexing plate 78 has a columnar projection 78A. The set jig 80 has an engagement hole 82, and the set jig 80 is fixed to the angle indexing plate 78 by fitting the engagement hole 82 to the columnar projection 78A.

The annular support plate 81 is connected to the connection fixing plate 8.
3 is connected and fixed to the angle indexing plate 78. At least two columns 84 are provided on the annular column mounting plate 81.
Is upright. A support plate 86 that supports the holding jig plate 85 is fixed to the upper end of the support column 84.

The holding jig plate 85 has guide bars 87 and 8
7. The load member 88 is provided integrally. Support plate 86
Has a guide hole 8 for guiding the guide rods 87, 87 vertically.
9, 89, through-hole 9 through which shaft portion 90 of load member 88 passes
1 is formed.

At the lower end of the load member 88, a pressing portion mounting member 92 is provided. The pressing member 92 is provided with a pressing member 93. Pressing member 9
3, a holding hole 94 for holding the rotating shaft 24 is provided as shown in an enlarged manner in FIG.

The set jig 80 has a set portion 95 at the upper end thereof on which the polygon mirror structure 21 before the magnet ring is inserted is set. The upper end surface of the set section 95 is used as a set reference plane 96 of the polygon mirror structure 21.

An escape hole 97 for the rotating shaft 24 is formed at the center of the upper end of the set portion 95. Set reference plane 9
6 has a mark "." 28A of the polygon mirror structure 21.
The mark “•” 96A corresponding to is attached. When the load member 88 shown in FIG. 19 is lifted, the polygon mirror assembly 21 aligns the marks “•” 28A and 96A, and places the insertion tube 27 on the lower side and the polygon mirror plate 22 on the upper side. Is set in the setting unit 95.

The pressing member 93 is provided with an annular pressing portion 98 around its periphery, and a ring-shaped elastic body 99 is interposed between the polygon mirror plate portion 22 and the annular pressing portion 98.

The polygon mirror structure 21 includes the load member 8
By lowering 8, as shown in FIG. 21, the ring-shaped elastic body 99 and the set jig 80 pinch and fix it from above and below. Since the ring-shaped elastic body 99 is located almost directly above the insertion tube 27 and presses the polygon mirror structure 21, deformation due to the sandwiching and fixing of the polygon mirror plate portion 22 is prevented. In addition, since the configuration is such that the polygon mirror constituting body 21 is sandwiched via the ring-shaped elastic body 99,
It is possible to prevent the pressing force from locally concentrating on the polygon mirror plate portion 22, and therefore, the polygon mirror structure 2 can be further improved.
Distortion and deformation of the polygon mirror plate 22 due to the pinching and fixing of 1 can be reduced.

The polygon mirror structure 21 has a side surface 2
9 is mirror-finished by a cutting tool (not shown). At that time, the control device 77 corrects and controls the cutting amount of the side surface 29 for each angle based on the measurement result.
8, each side surface 29 is cut so as to be parallel to the axis of the rotating shaft 24 as indicated by reference numeral 29 '.

After the mirror finishing, the multi-pole magnet 31 is inserted into the polygon mirror structure 21. And
It is incorporated in a polygon scanner unit as shown in FIG. In FIG. 22, reference numeral 100 denotes a stator. The stator 100 has a circuit board 101. The circuit board 101 is provided with a stator yoke 102.

[0097] The stator yoke 102 is
03 is fixed to the circuit board 101. A winding coil 104 is provided on the outer periphery of the stator yoke 102. A thrust bearing 105 and a radial bearing 106 are provided inside the stator yoke 102, and the rotating shaft 24 of the polygon mirror assembly 21 is rotatably supported by the thrust bearing 105 and the radial bearing 106.

The winding coil 104 is opposed to the multi-pole magnet 31 from the inner peripheral side, and by controlling the energization of the winding coil 104, the polygon mirror 2
1 is driven to rotate, the multipolar magnet 31, the winding coil 104, the stator yoke 102, the control circuit element 107,
The circuit board 100 forms a brushless motor.

Although the embodiment of the present invention has been described above, the bearing device according to the present invention can also be applied to the conventional rotor 1A shown in FIG.

That is, the rotor 1A shown in FIG. 4 is set on the bearing device 20 as shown in FIG.
It is also possible to measure the amount of shake. In this case, the lower end face 3d of the rotor 1A is used as a measurement reference plane.

[0101]

According to the invention of the air bearing device according to the invention of the rotation driving method according to the first and second aspects, since the method is a method of rotating the rotor after floating the rotation shaft, Damage to the rotating shaft can be prevented.

According to the third, fourth, fifteenth, and sixteenth aspects of the present invention, the rotor can be rotated while being supported by air, so that damage to the rotating shaft can be prevented.

According to the fifth and seventeenth aspects of the present invention, the columnar thrust bearing is formed of a material having a large number of porous members, and air is supplied to the lower end of the rotating shaft through the porous members to lift the rotating shaft. With this configuration, the rotating shaft can be reliably levitated.

According to the sixth and eighteenth aspects of the invention, since the upper end of the columnar thrust bearing facing the lower end of the rotary shaft has a curved surface corresponding to the shape of the lower end of the rotary shaft. The rotating shaft can be stably levitated.

According to the seventh and nineteenth aspects of the present invention, since the cylindrical radial bearing for supporting the rotary shaft rotatably in the radial direction is provided, the rotary shaft can be stably rotated. It is possible.

According to the eighth and twentieth aspects of the present invention, since the cylindrical radial bearing is made of a material having a large number of porous bodies, air is blown to the peripheral surface of the rotary shaft to be rotatable by the air. The shaft can be rotatably supported, so that it is possible to reliably prevent the peripheral surface of the rotation shaft from being damaged, and to further stably rotate the rotation shaft.

According to the ninth and twenty-first aspects of the present invention, since the cylindrical radial bearing is provided on the air pressure holding body for holding the air pressure inside, the air pressure is supplied to the rotary shaft via the porous material. Air stabilization.

According to the tenth and twenty-second aspects of the present invention, the air stabilized by the cylindrical air pressure holding member is supplied to the rotor from the air outlet, so that the rotor can be rotated more stably. It is possible to do.

According to the present invention, air from the same air supply source can be supplied to the cylindrical thrust bearing and the cylindrical air pressure holder. is there.

According to the thirteenth and twenty-fifth aspects of the invention, the air guided along the axial direction via the porous portion of the cylindrical radial bearing contributes to the floating of the rotor. The levitation force can be obtained stably.

According to the twenty-sixth aspect of the present invention, the rotor can be rotated after the rotor is levitated, and the rotating shaft is levitated by air while the rotor is rotating. Since the peripheral surface is protected by the air layer, damage to the rotating shaft can be prevented.

Further, since the air stabilized by the cylindrical air pressure holding member is supplied to the rotor from the air outlet, the rotor can be rotated stably.

Further, since a cylindrical thrust bearing and a cylindrical radial bearing are provided and air is supplied to the rotating shaft through the porous member, the rotation of the rotating shaft can be stabilized.

According to the twenty-seventh aspect, the air guided in the axial direction through the porosity of the cylindrical radial bearing contributes to the floating force of the rotor, so that the floating force can be stably obtained. .

[Brief description of the drawings]

FIG. 1 is an exploded perspective view of a conventional polygon mirror structure.

FIG. 2 is a schematic diagram showing a tilt angle of a mirror surface of a polygon mirror plate.

FIG. 3 is an explanatory diagram showing an example of deterioration of writing quality when a polygon mirror plate has a problem of surface tilt.

FIG. 4 is a plan view showing an example of a bearing device used for inspecting a surface runout characteristic of a cylindrical body constituting a part of a polygon mirror structure.

FIG. 5 is an exploded perspective view showing another example of a conventional polygon mirror structure.

FIG. 6 is a longitudinal sectional view of the air bearing device according to the present invention.

FIG. 7 is a sectional view of the polygon mirror structure shown in FIG. 5;

FIG. 8 is a cross-sectional view of the air supply path structure shown in FIG.

FIG. 9 is a cross-sectional view of the air discharge path structure shown in FIG. 6;

FIG. 10 is a cross-sectional view of the air discharge path structure shown in FIG. 9 and is an explanatory view of an air discharge port.

FIG. 11 is a cross-sectional view of the cylindrical air pressure holder shown in FIG.

12 is an enlarged sectional view of the cylindrical radial bearing shown in FIG.

FIG. 13 is an enlarged sectional view of the cylindrical thrust bearing shown in FIG.

FIG. 14 is a sectional view of the cylindrical air pressure holding member shown in FIG.

15 is a partial cross-sectional view showing a state where the air bearing device shown in FIG. 6 is set in a measuring device.

16 is a diagram showing a state where the measuring device shown in FIG. 15 is connected to a processing device.

17 is an angle development diagram for explaining a relationship between a shake amount obtained by a shake calculation device shown in FIG. 16 and a rotation angle of a rotor.

FIG. 18 is an explanatory diagram exaggeratingly showing the inclination between the rotation axis and the polygon mirror plate.

FIG. 19 is a partially enlarged view showing an example of the processing apparatus shown in FIG.

20 is a partially enlarged view of a setting mechanism of the processing apparatus shown in FIG. 19, and shows a state before pressing and holding the polygon mirror structure.

21 is a partially enlarged view of a setting mechanism of the processing apparatus shown in FIG. 19, and shows a state after the polygon mirror structure has been pressed and clamped;

FIG. 22 is a cross-sectional view of a main part of a polygon mirror scanner configured using the polygon mirror structure shown in FIG.

23 is a cross-sectional view showing a state where the rotor shown in FIG. 4 is supported on an air bearing device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 20 ... Air bearing device 21 ... Polygon mirror structure 24 ... Rotating shaft 27 ... Insertion cylinder 29 ... Side surface 31 ... Multipolar magnet (magnet ring) 33 ... Air supply path structure 34 ... Air discharge path structure 37 ... Air supply Road 50… Air outlet

Continued on the front page F-term (reference) 2H045 AA13 AA24 AA27 3J102 AA02 AA07 BA03 BA13 BA17 BA18 CA10 CA31 EA02 EA08 EA18 GA02 5C072 AA03 BA13 HA02 HA12 XA01 XA05

Claims (27)

[Claims] 1. A rotary driving method for rotating a rotor having a rotary shaft mounted on a cylindrical body by air, wherein after floating by the air pressure of the rotary shaft, air is blown on an inner peripheral wall of the cylindrical body. A method for driving the rotation of a rotor, wherein the rotation is performed by spraying. 2. A rotor composed of a polygon mirror having a mirror surface formed on a side surface and a rotation shaft inserted into a central portion, and a lower part into which a magnet ring is inserted is integrally formed with a rotor composed of a polygon mirror. A rotation driving method of rotating the rotation shaft while supporting the rotation shaft by air pressure, and then blowing air on an inner peripheral wall of the insertion cylinder to rotate the rotor. The child's rotation drive method. 3. An air bearing device for rotationally driving a rotor having a rotating shaft mounted on a cylindrical body by air, the air supplying device supplying air to an inner peripheral wall of the cylindrical body. An air supply path structure having a passage, and air directed toward the inner peripheral wall to rotate in a certain direction while supporting the rotor facing the inner peripheral wall of the tubular body and communicating with the air supply path. An air bearing device for a rotor of a rotor, comprising: an air discharge path constituting member formed with an air discharge port for discharging. 4. The rotating device according to claim 3, wherein the air supply path structure has a columnar thrust bearing which faces the lower end of the rotating shaft and rotatably supports the rotating shaft in the axial direction. Child air bearing device. 5. The rotor air according to claim 4, wherein the columnar thrust bearing is made of a material having a large number of pores, and air is supplied to the lower end of the rotary shaft through the pores. Bearing device. 6. The rotor according to claim 5, wherein the columnar thrust bearing has a curved upper surface facing a lower end of the rotating shaft, the upper end facing the lower end of the rotating shaft. Air bearing device. 7. The air discharge path constituting body is provided with a cylindrical radial bearing that rotatably supports the rotating shaft in a radial direction. Item 2. An air bearing device for a rotor according to item 1. 8. The rotor according to claim 7, wherein the cylindrical radial bearing is made of a material having a large number of pores, and air is supplied to a peripheral surface of the rotating shaft through the porous material. Air bearing device. 9. The air discharge path component has a cylindrical air pressure holding member for holding air pressure therein, and the cylindrical radial bearing is provided on the cylindrical air pressure holding member. The air bearing device for a rotor according to claim 8, wherein 10. The air discharge path constituting body is formed with a cylindrical setting portion for setting the cylindrical air pressure holding member, and the air discharge port is formed on a peripheral wall of the cylindrical setting portion in a circumferential direction thereof. An air communication passage formed between the cylindrical air pressure holding member and the cylindrical set portion is formed at a predetermined interval to communicate the inside of the cylindrical air pressure holding member and the air discharge port. The air bearing device for a rotor according to claim 9, wherein: 11. The air supply path structure, wherein the air supply path supplies air to the cylindrical thrust bearing and a thrust bearing branch path for supplying air to the cylindrical thrust bearing. The air bearing device for a rotor according to claim 10, further comprising a branch passage for holding air pressure. 12. The air is supplied from the thrust bearing branch passage through a porous portion of the cylindrical thrust bearing to a lower end portion of the rotary shaft, and is supplied from the air pressure holding branch passage to the cylindrical radial passage. The air bearing device for a rotor according to claim 11, wherein the air is supplied to a peripheral surface of the rotating shaft via a porous portion of the bearing. 13. A part of the air supplied to the inside of the cylindrical air pressure holding body is supplied to the inside of the cylindrical body by being guided along the axial direction through the porosity of the cylindrical radial bearing. The air bearing device for a rotor according to claim 12, wherein the rotor is levitated. 14. The cylindrical body according to claim 13, wherein a polygon mirror structure having a mirror surface on a side surface is inserted and a ring-shaped magnet is mounted on an inner peripheral wall thereof. The air bearing device for a rotor according to Item 1. 15. A rotor composed of a polygon mirror structure having a mirror surface formed on a side surface and a rotation shaft inserted into a central portion, and a lower portion into which a magnet ring is inserted is integrally formed with a rotor. An air bearing device of a rotor that is driven to rotate while being supported by an air supply path having an air supply path for supplying air toward an inner peripheral wall of the insertion tube; An air discharge path structure that is communicated and has an air discharge port formed to discharge air toward the inner peripheral wall to rotate in a certain direction while supporting the rotor facing the inner peripheral wall of the insertion cylinder; An air bearing device for a rotor, comprising: 16. The rotation according to claim 15, wherein the air supply path structure has a columnar thrust bearing which faces the lower end of the rotation shaft and rotatably supports the rotation shaft in the axial direction. Child air bearing device. 17. The rotor air according to claim 16, wherein the columnar thrust bearing is made of a material having a large number of porosity, and air is supplied to a lower end portion of the rotating shaft through the porous material. Bearing device. 18. The rotor according to claim 17, wherein the columnar thrust bearing has a curved upper surface facing a lower end of the rotating shaft corresponding to a lower end of the rotating shaft. Air bearing device. 19. The air discharge path constituting body is provided with a cylindrical radial bearing that rotatably supports the rotating shaft in a radial direction. Item 2. An air bearing device for a rotor according to item 1. 20. The rotor according to claim 19, wherein the cylindrical radial bearing is made of a material having a large number of pores, and air is supplied to the peripheral surface of the rotating shaft through the porous pieces. Air bearing device. 21. The air discharge path member has a cylindrical air pressure holding member for holding air pressure therein, and the cylindrical radial bearing is provided on the cylindrical air pressure holding member. The air bearing device for a rotor according to claim 20, wherein: 22. The air discharge path constituting body is formed with a cylindrical set portion in which the cylindrical air pressure holding member is set, and the air discharge port is formed on a peripheral wall of the cylindrical set portion in a circumferential direction thereof. An air communication path is formed between the cylindrical air pressure holding member and the cylindrical set portion to communicate the inside of the cylindrical air pressure holding member and the air discharge port. The air bearing device for a rotor according to claim 21, wherein: 23. The air supply path structure, wherein the air supply path supplies air to the thrust bearing branch passage for supplying air toward the cylindrical thrust bearing and the inside of the cylindrical air pressure holding body. 23. The air bearing device for a rotor according to claim 22, further comprising a branch passage for holding air pressure. 24. The air is supplied from the thrust bearing branch passage to the lower end of the rotary shaft via the porous of the cylindrical thrust bearing, and is also supplied from the air pressure holding branch passage to the cylindrical radial. 24. The air bearing device for a rotor according to claim 23, wherein the air is supplied to a peripheral surface of the rotating shaft via a porous portion of the bearing. 25. A part of the air supplied to the inside of the cylindrical air pressure holding member is guided along the axial direction through the porous portion of the cylindrical radial bearing, and is supplied to the inside of the insertion tube. The air bearing device for a rotor according to claim 24, wherein the rotor is levitated. 26. A rotor comprising a polygon mirror structure having a mirror surface formed on a side surface, a rotating shaft mounted at a central portion, and a lower part on which a magnet ring is mounted integrally formed with a rotor having a polygon mirror structure. An air bearing device of a rotor that rotates while being driven, and is connected to an air supply path structure having an air supply path for supplying air toward an inner peripheral wall of the insertion tube, and is connected to the air supply path. And an air discharge path component that discharges air toward the inner peripheral wall to rotate in a certain direction while supporting the rotor facing the inner peripheral wall of the insertion cylinder, and the air supply path configuration The body is provided with a columnar thrust bearing having a large number of porous bodies and facing the lower end of the rotary shaft so as to rotatably support the rotary shaft in the axial direction. A cylindrical radial bearing that holds a plurality of porous bodies and supports the rotating shaft so as to be rotatable in a radial direction; The discharge path constituting body is formed with a cylindrical set portion on which the air pressure holding member is set, and the air discharge port is formed on a peripheral wall of the cylindrical set portion at predetermined intervals in a circumferential direction thereof, An air communication path communicating between the inside of the cylindrical air pressure holder and the air discharge port is formed between the cylindrical air pressure holder and the cylindrical set portion, and the air supply path structure includes:
The air supply path includes a thrust bearing branch passage for supplying air toward the cylindrical thrust bearing and an air pressure holding branch passage for supplying air to the inside of the cylindrical air pressure holder. An air bearing device for a rotor, characterized in that: 27. A part of the air supplied to the inside of the cylindrical air pressure holding member is guided to the inside of the insertion tube by being guided along the axial direction through the porous portion of the cylindrical radial bearing. The air bearing device for a rotor according to claim 26, wherein the rotor is levitated.