JP3695532B2 - Shaft tilt angle measuring apparatus and measuring method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a shaft tilt angle measuring device standing on an act base of an optical pickup objective lens unit used for, for example, a CD, a DVD, and the like, and a measuring method thereof.
[0002]
[Prior art]
One example of the objective lens unit is shown in FIGS. This is because the act base 2 with the shaft 1 standing at the center and the boss 3a formed at the center can slide on the shaft 1 along the axis O direction of the shaft 1 and swing around the axis O. The act base 2 with the lens holder 3 interposed therebetween, the focus coil 4 fitted around the boss 3a, a pair of tracking coils 5 disposed on both side surfaces of the lens holder 3, and the lens holder 3 therebetween. A pair of magnets 6 arranged on an upright plate 2 a erected from both sides of the lens, a pair of yokes 9 fixed to the act base 2 by screws 8 and having both ends inserted into the through holes 3 b of the lens holder 3, and an act base 2 and a printed circuit board 10 disposed on an upright plate 2b that is erected from the end of the printed circuit board 10. Lead wires 10a extending from the printed circuit board 10 are in contact with the tracking coils 5 and the focus coil 4. The focus coil 4 is energized to slide the lens holder 3 along the axis O in the focusing directions a and b, thereby focusing the objective lens 7 provided on the lens holder 3 with a disc (not shown). ), The tracking coil 5 is energized and the lens holder 3 is swung around the axis O in the tracking directions c and d to follow a predetermined track of the disk.
[0003]
In the above configuration, in order to stabilize the focus servo characteristic and the tracking servo characteristic, the shaft 1 needs to be accurately upright with respect to the act base 2.
[0004]
Therefore, conventionally, an example of a technique for measuring the inclination angle of the shaft 1 and measuring whether or not the upright state is within an allowable range is disclosed in Japanese Utility Model Laid-Open No. 2-128908. As shown in FIG. 9 and FIG. 10, it is composed of a surface plate 13 in which a pair of support columns 12 are erected, and a plurality of projectors 14 and light receivers 15 arranged at predetermined intervals on each support column 12, The act base 2 is placed on the surface plate 13 so that the side edge of the shaft 1 is positioned between each projector 14 and each light receiver 15, and the act base is centered on the axis O of the shaft 1. 2 is intermittently rotated every predetermined angle, and while the rotation is stopped, a light beam projected from each light projector 14 and half blocked at the side edge of the shaft 1 is received by each light receiver 15, and received by each light receiver 15. It is conceivable to measure the inclination angle α of the shaft 1 from the change in quantity.
[0005]
[Problems to be solved by the invention]
In the conventional configuration, the change in the amount of light received by each light receiver 15 is extremely small.
An error is likely to occur in the inclination angle α of the shaft 1 measured based on the change. Further, when the act base 2 is intermittently rotated every predetermined angle, the axis O of the shaft 1 may be displaced, and precise measurement is difficult.
[0006]
An object of the present invention is to provide a shaft tilt angle measuring apparatus and a measuring method thereof capable of accurately measuring the tilt angle of the shaft without causing an error in view of the above-described conventional drawbacks.
[0007]
[Means for Solving the Problems]
In order to achieve the above object, the invention according to claim 1 is an apparatus for measuring a tilt angle of a shaft erected on an act base of an objective lens unit, and comprises a measuring table and an auto placed above the measuring table. An intermediate frame having a collimator, a measuring jig with a mirror, and a mirror for mounting on an act base, the measuring table being supported by the base so as to be swingable around a horizontal horizontal axis; The intermediate frame is provided with a center base supported so as to be swingable about a horizontal longitudinal axis, and the measuring jig is integrally extended on the lower surface of the jig main body with the mirror disposed on the upper surface. The act base is placed on the upper surface of the center base, and a light beam is projected from the autocollimator onto a mirror placed on the act base, and the light is projected on the basis of the inclination angle of the reflected light. Adjust the level of the intermediate frame and the center platform. Then, the act base is placed in a horizontal state, and then the sleeve of the measuring jig is fitted to the shaft, the jig body is intermittently rotated around the axis of the shaft at predetermined angles, and the rotation is stopped. The light beam is projected from the autocollimator to the mirror of the measuring jig, and the tilt angle of the shaft is measured a plurality of times.
[0008]
According to the above configuration, the act base is placed on the upper surface of the center base, the light beam is projected from the autocollimator to the mirror placed on the act base, and the center base is horizontally and vertically based on the tilt angle of the reflected light. The act base can be accurately placed in a horizontal state only by swinging around the axis and swinging the intermediate frame around the horizontal horizontal axis.
[0009]
In addition, the measuring jig with a mirror fitted on the shaft is intermittently rotated around the axis of the shaft, and while the rotation is stopped, a light beam is projected from the autocollimator to the mirror, and the tilt angle of the shaft is adjusted several times. By simply averaging the measured values, it is possible to accurately determine the tilt angle of the shaft and easily check whether the tilt angle of the shaft is within the allowable range. In the measurement, since it is not necessary to move the act base as in the prior art, it is possible to measure accurately so as not to cause an error. Also, since the structure of the measuring jig is simple,
Production costs are cheap.
[0010]
The invention according to claim 2 is an apparatus for measuring a tilt angle of a shaft erected on an act base , wherein a jig body having a mirror disposed on an upper surface, and a sleeve integrally extending on the lower surface of the jig body, The act base is placed on a measurement table, the sleeve is fitted to the shaft, the jig body is intermittently rotated around the axis of the shaft every predetermined angle, While the rotation is stopped, a light beam is projected onto a mirror from an autocollimator arranged above the measurement table, and the tilt angle of the shaft is measured a plurality of times .
[0011]
According to the above configuration, the measuring jig is fitted on the shaft, the light beam is projected from the autocollimator onto the mirror of the measuring jig, and the tilt angle of the shaft is measured from the tilt angle of the reflected light. In the measurement, since it is not necessary to move the act base as in the prior art, the tilt angle of the shaft can be determined very precisely.
[0012]
Since the structure of the measuring jig is simple, the production cost is low. Further, the mirror is intermittently rotated around the axis of the shaft, and while the rotation is stopped, a light beam is projected from the autocollimator to the mirror, and the tilt angle of the shaft is measured a plurality of times. By simply averaging the measured values, it is possible to accurately determine the tilt angle of the shaft and easily check whether the tilt angle of the shaft is within an allowable range.
[0013]
The invention according to claim 3 is a method for measuring an inclination angle of a shaft erected on an act base, wherein the horizontal vertical axis is provided on a base of the measurement table via an intermediate frame that can swing around the horizontal horizontal axis. The act base is placed on the upper surface of a center platform supported so as to be swingable around the center,
By projecting a light beam from an autocollimator placed above the measurement table onto a mirror placed on the act base, and adjusting the horizontality of the intermediate frame and the center table based on the inclination angle of the reflected light, the act The base is in a horizontal state, and then the sleeve of a measuring jig having a jig body with a mirror disposed on the upper surface and a sleeve integrally extended on the lower surface of the jig body is fitted to the shaft, The jig body is intermittently rotated around the axis of the shaft by a predetermined angle, and while the rotation is stopped, a beam is projected from the autocollimator to the mirror of the measuring jig, and the tilt angle of the shaft is measured multiple times. It is characterized by that.
[0014]
According to the above configuration, the tilt accuracy of the shaft erected on the act base is measured multiple times by combining the measurement table and autocollimator with the mirror placed on the act base and the measurement jig with the mirror fitted to the shaft. Because it is not necessary to move the act base as before, when measuring it,
The tilt angle of the shaft can be determined very precisely.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
1 and 2 show a state in which the tilt angle α of the shaft 1 standing on the act base 2 of the objective lens unit is measured by the shaft tilt angle measuring apparatus according to one embodiment of the present invention. The measuring table 17, the autocollimator 18 disposed above the measuring table 17, the measuring jig 20 with the mirror 19, and the mirror 21 for mounting on the act base 2 are provided. Since the configuration of the objective lens unit is the same as that shown in FIGS. 6 to 8, the description thereof is omitted.
[0016]
As shown in FIGS. 1 and 2, the measurement table 17 includes an intermediate frame 17b supported on a base 17a so as to be swingable about a horizontal horizontal axis X, and a horizontal vertical axis Y centered on the intermediate frame 17b. And an arcuate rack 23 is formed at the front edge of the intermediate frame 17b, and an operation handle 25 is fixed to a support shaft of a pinion 24 that meshes with the rack 23. Further, an arc-shaped rack 26 is formed on the side edge of the center base 17c, and an operation handle 28 is fixed to a support shaft of a pinion 27 that meshes with the rack 26.
[0017]
According to the above configuration, when the act base 2 is placed on the center base 17c, the operation handle 25 is rotated in the forward and reverse directions, whereby the intermediate frame 17b is rotated about the horizontal horizontal axis X via the pinion 24 and the rack 23. By swinging and rotating the operation handle 27 forward and backward, the act base 2 can be precisely leveled simply by swinging the center base 17c about the horizontal longitudinal axis Y via the pinion 27 and the rack 26. be able to.
[0018]
As shown in FIG. 1, the autocollimator 18 is fixed to the tip of a horizontal arm 30a extending in the horizontal direction from the upper end of a rotating support column 30 that is erected on the side of the base 17a. By rotating the moving column 30 back and forth by a small angle, the autocollimator 18 is alternately arranged with respect to the mirror 21 placed on the act base 2 and the mirror 19 of the measuring jig 20 fitted to the shaft 1. (See FIG. 3).
[0019]
As shown in FIGS. 3 and 4, the measuring jig 20 includes a jig body 20a having a mirror 19 disposed on the upper surface, a sleeve 20b integrally extending on the lower surface of the jig body 20a, and a jig body 20a. And an operating rod 20c extending horizontally from the shaft 1, the sleeve 20b is fitted to the shaft 1, the operating rod 20c is manually operated, and the jig body 20a is rotated around the axis O of the shaft 1 by a predetermined angle (this implementation). In this mode, the light is intermittently rotated every 90 ° (see FIG. 5), and light is projected from the autocollimator 18 to the mirror 19 while the rotation is stopped. From the inclination angles θ1 to θ4 of the reflected light, the shaft 1 Is measured a plurality of times.
[0020]
According to the above configuration, since the structure of the measuring jig 20 is simple, the manufacturing cost is low. Further, the mirror 19 is intermittently rotated around the axis O of the shaft 1, and light is projected from the autocollimator 18 to the mirror 19 while the rotation is stopped, and the inclination angle α of the shaft 1 is measured a plurality of times. Therefore, the inclination angle α of the shaft 1 can be accurately determined only by averaging the measured values.
[0021]
The method of measuring the tilt angle of the shaft 1 will be described. As shown in FIGS. 2 and 3, the act base 2 is placed on the center base 17 c, and the mirror 21 is placed on the act base 2. A light beam is projected onto the mirror 21, and the act base 2 is brought into a horizontal state by adjusting the horizontality (X, Y) of the intermediate frame 17b and the center base 17c based on the inclination angle θ5 of the reflected light.
[0022]
Next, as shown in FIGS. 3 and 4, the sleeve 20b of the measuring jig 20 is fitted to the shaft 1, the operating rod 20c is manually operated, and the jig main body 20a is rotated around the axis O of the shaft 1, for example. While rotating intermittently approximately every 90 °, light is projected from the autocollimator 18 to the mirror 19 while the rotation is stopped, and the tilt angle α of the shaft 1 is measured a plurality of times from the tilt angles θ1 to θ4 of the reflected light. However, the inclination angle α of the shaft 1 is determined by averaging the measured values.
[0023]
According to the above configuration, the measurement table 17 and the autocollimator 18 are combined with the mirror 21 placed on the act base 2 and the measurement jig 20 with the mirror 19 fitted to the shaft 1 to stand on the act base 2. The tilt angle α of the shaft 1 is measured a plurality of times, and since the act base 2 does not need to be moved as in the prior art, the tilt angle α of the shaft 1 is extremely precise. Can be determined.
[0024]
In the above-described embodiment, the case where the inclination angle α of the shaft standing on the act base of the optical pickup objective lens unit is measured has been described as an example. The present invention can also be applied to the case where the inclination angle α of the shaft 1 used for the measurement is measured.
[0025]
【The invention's effect】
According to the first aspect of the present invention, the act base is placed on the upper surface of the center base, the light beam is projected from the autocollimator onto the mirror placed on the act base, and the inclination angle of the reflected light is The act base can be precisely leveled by merely swinging the center platform about the horizontal vertical axis and swinging the intermediate frame about the horizontal horizontal axis.
[0026]
In addition, the measuring jig with a mirror fitted on the shaft is intermittently rotated around the axis of the shaft, and while the rotation is stopped, a light beam is projected from the autocollimator to the mirror, and the tilt angle of the shaft is adjusted several times. By simply averaging the measured values, it is possible to accurately determine the tilt angle of the shaft and easily check whether the tilt angle of the shaft is within the allowable range. In the measurement, since it is not necessary to move the act base as in the prior art, it is possible to measure accurately so as not to cause an error. Also, since the structure of the measuring jig is simple,
Production costs are cheap.
[0027]
According to the invention described in claim 2, a measuring jig is fitted on the shaft, a light beam is projected from the autocollimator onto the mirror of the measuring jig, and the tilt angle of the shaft is measured from the tilt angle of the reflected light. In the measurement, since it is not necessary to move the act base as in the prior art, the tilt angle of the shaft can be determined very precisely.
[0028]
Since the structure of the measuring jig is simple, the production cost is low. Further, the mirror is intermittently rotated around the axis of the shaft, and while the rotation is stopped, a light beam is projected from the autocollimator to the mirror, and the tilt angle of the shaft is measured a plurality of times. By simply averaging the measured values, it is possible to accurately determine the tilt angle of the shaft and easily check whether the tilt angle of the shaft is within an allowable range.
[0029]
According to the invention described in claim 3, the shaft of the shaft erected on the act base is combined by combining the measuring table and the autocollimator with the mirror mounted on the act base and the measuring jig with the mirror fitted to the shaft. Inclination accuracy is measured a plurality of times. Moreover, since it is not necessary to move the act base as in the prior art, the inclination angle of the shaft can be determined very precisely.
[Brief description of the drawings]
FIG. 1 is a perspective view showing a shaft tilt angle measuring apparatus according to an embodiment of the present invention.
FIG. 2 is a plan view of the same part cut out.
3 is an AA arrow view of FIG.
4 is a BB arrow view of FIG. 2;
FIG. 5 is a schematic plan view showing the measurement procedure.
FIG. 6 is a plan view of an objective lens unit.
7 is a view taken along the line CC in FIG. 6;
8 is a DD arrow view of FIG. 6;
FIG. 9 is a side view showing a conventional example.
FIG. 10 is a cross-sectional view of the same.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Shaft 2 Act base 17 Measurement stand 17a Base 17b Intermediate frame 17c Center stand 18 Autocollimator 19 Mirror 20 Measurement jig 20a Jig body 20b Sleeve 21 Mirror α Shaft inclination angle X Horizontal horizontal axis Y Horizontal vertical axis

Claims (3)

  An apparatus for measuring the tilt angle of a shaft erected on an act base of an objective lens unit, which is placed on the act base, an autocollimator disposed above the measurement stand, a measuring jig with a mirror, and the act base The measuring table is supported by the base so as to be swingable about a horizontal horizontal axis, and supported by the intermediate frame so as to be swingable about a horizontal vertical axis. And the measuring jig includes a jig main body having a mirror disposed on the upper surface, and a sleeve integrally extending on the lower surface of the jig main body. A base is placed, a light beam is projected from the autocollimator onto a mirror placed on the act base, and the level of the intermediate frame and the center base is adjusted on the basis of the inclination angle of the reflected light. Level the base, then The measurement jig sleeve is fitted to the shaft, the jig body is rotated intermittently around the axis of the shaft at a predetermined angle, and light is projected from the autocollimator to the measurement jig mirror while the rotation is stopped. Then, a shaft tilt angle measuring device that measures the tilt angle of the shaft a plurality of times. An apparatus for measuring a tilt angle of a shaft erected on an act base , comprising a jig body having a mirror disposed on the upper surface and a sleeve integrally extending on the lower surface of the jig body The act base is placed on the measuring table, the sleeve is fitted to the shaft, the jig body is intermittently rotated around the axis of the shaft at a predetermined angle, and the rotation of the measuring table is stopped while the rotation is stopped. A shaft tilt angle measuring apparatus which projects a light beam from an autocollimator disposed above to a mirror and measures the tilt angle of the shaft a plurality of times .   This is a method for measuring the tilt angle of a shaft erected on an act base, and is supported on the base of the measuring table so as to be swingable about the horizontal vertical axis through an intermediate frame that can swing about the horizontal horizontal axis. The act base is placed on the upper surface of the central base, a light beam is projected from the autocollimator placed above the measurement stand to the mirror placed on the act base, and the intermediate frame is based on the tilt angle of the reflected light. And adjusting the level of the central base to bring the act base into a horizontal state. Next, the mirror has a jig body disposed on the upper surface and a sleeve integrally extending on the lower surface of the jig body. The sleeve of the measuring jig is fitted to the shaft, the jig body is intermittently rotated around the axis of the shaft at a predetermined angle, and light is projected from the autocollimator to the mirror of the measuring jig while the rotation is stopped. And that sha Shaft inclination angle measuring method and measuring the inclination angle of the bets multiple times.

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