JP2000283718A - Position detector and information recorder using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a position detector which can detect the positional information of an object with high accuracy and is suitable for hard disk drivers and an information recorder. SOLUTION: A position detector is provided with an interferometer, and a plate spring member which is firmly fixed to the interferometer and can come into contact with an object to be inspected. The detector detects the positional information of the object from interference signals obtained from the multiplexed luminous flux of signal light, based on the reflected light of the light emitted from the interferometer reflected from the plate spring member and reference light formed by means of the interferometer. The plate spring member has a plate-like shape and is firmly fixed to the interferometer at a fixed angle from the light emitting surface of the interferometer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a position detecting device for detecting a position change (position information) of a test object such as a magnetic head of a hard disk drive, and an information recording device using the same.

In particular, the present invention can be suitably applied to a hard disk drive (hereinafter referred to as an HDD) manufacturing apparatus used in a computer, among which an apparatus for writing a servo track signal to a hard disk in an HDD with high accuracy.

[0003]

2. Description of the Related Art FIG. 5 is an explanatory view of a conventional information recording apparatus for writing a servo track signal on a hard disk in an HDD.

In FIG. 5, HDD is a hard disk drive, HD is a hard disk, SLID is a slider, ARM1 is a magnetic head arm, VCM is a voice coil motor, and VCMD is a voice coil motor driver for driving and controlling the voice coil motor VCM. OH
D is a spindle that is the center of rotation of the hard disk HD,
O is a rotation axis of the magnetic head arm ARM1.

[0005] A magnetic recording medium is deposited on the surface of the hard disk HD. The hard disk HD always rotates at a high speed around the spindle OHD, and a magnetic head is arranged close to the surface of the hard disk HD.
The magnetic head has a rotation center O outside the hard disk HD.
Is installed in a substantially rectangular parallelepiped portion called a slider SLID attached to the tip of a magnetic head arm ARM1 having a magnetic head arm ARM1. It can be moved.

Accordingly, the rotating hard disk H
Magnetic information can be written or read at an arbitrary position (track) on the surface of the disk-shaped hard disk HD by the magnetic head moving in an arc with D.

In the magnetic recording system on the surface of the hard disk HD, first, the rotation center (spindle) OHD of the hard disk HD is divided into a plurality of annular tracks having different concentric circle radii, and each circle is further divided. The annular track is also divided into sub-several arcs, and is finally recorded and reproduced in the sub-several arc regions in a time series along the circumferential direction.

Meanwhile, as a recent trend, there is a demand for increasing the recording capacity of a hard disk, and there is a demand for increasing the density of information recorded on the hard disk. As a means for increasing the density of information recorded on a hard disk, it is effective to reduce the track width divided concentrically to improve the recording density in the radial direction.

The recording density in the radial direction is track density per one inch length (track pitch) TPI (track).
/ Inch), which is currently about 10,000 TPI. This means that the track spacing is about 3 microns. In order to determine such a fine track pitch, it is necessary to position the magnetic head in the radial direction of the hard disk HD at a resolution of about 1/50 of the track width (0.05 micron) and write a servo track signal in advance. There is. The key technology here is
This is to sequentially write servo track signals while performing high-resolution positioning in a short time.

FIG. 5 is a schematic view showing a conventional positioning device for writing a servo track signal. In FIG. 5, RTP is a rotary positioner. PROD
Is push rod, ARM2 is push rod PROD
Arm, MO is a positioning control motor, RE is a rotary encoder for detecting the amount of rotation of the rotating shaft of the motor MO, SP is a motor that analyzes the detection output from the rotary encoder RE, and writes the servo head signal to the servo track signal writing position of the magnetic head. A signal processor that issues a positioning command signal,
MD is a motor driver that drives the motor MO according to a command signal of the signal processor SP.

Conventionally, as shown in FIG. 5, a cylindrical surface of a push rod PROD is pressed against a side surface of a magnetic head arm ARM1, and feedback is provided by a system of a rotary encoder RE, a signal processor SP, and a motor driver MD (rotary positioner RTP). Under control, the arm ARM2 is rotated by the motor MO, and the magnetic head arm ARM1 is positioned while being minutely fed via the push rod PROD, and the servo track signal is sequentially written.

At this time, in order to secure the contact, usually, a slight current is applied to the voice coil motor VCM to push the push rod PROD also from the head arm ARM1 side. However, when vibrations due to rotation of the hard disk HD and the like are transmitted to the head arm ARM1 and further transmitted to the motor MO via the cylindrical surface of the push rod PROD, a limit is imposed on the high-precision positioning of the rotary positioner system RTP. In order to improve the ability to write information such as a servo track signal, further measures have been required.

[0013]

In the information recording apparatus shown in FIG. 5, recently, assuming highly accurate positioning,
Do not press the magnetic head arm mechanically,
A method for measuring and controlling the movement of the magnetic head arm with high precision by optical means has also been devised. FIG. 6 is an example of such an apparatus.

In FIG. 6, HeNe is a laser light source, M
Reference numerals 1 and M2 are mirrors, BS is a beam splitter, CC is a retroreflector such as a corner cube provided on the magnetic head arm ARM1, and PD is a light receiving element.

In this apparatus, the laser light source HeNe,
A Michelson-type interferometer is constituted by the mirrors M1 and M2, the beam splitter BS, and the retroreflector CC, and the retroreflector CC to the mirror M1 and the retroreflector C
The light receiving element PD detects interference light between the light beams L1 and L2 that have passed through the mirror C2 and the magnetic head arm A, respectively.
The position information of RM1 has been obtained.

Then, based on the obtained detection signal, the signal processor SP issues a command to control the current flowing from the voice coil motor driver VCMD to the voice coil motor VCM, thereby directly controlling the magnetic head arm ARM.
By moving 1, appropriate control is added.

However, in such an apparatus, it is necessary to mount a retro-reflector CC such as a corner cube on the magnetic head arm ARM1, and there is a problem that the space is troublesome, the mounting and dismounting is troublesome, and the control characteristics are deteriorated due to an increase in weight. Cheap.

According to the present invention, the position of an object can be determined with high reliability and high accuracy without the need to provide a special member on the object side.
An object of the present invention is to provide a position detection device capable of detecting a position with high resolution and positioning the object, and an information recording device using the same.

It is another object of the present invention to provide a position detecting device suitable for a manufacturing apparatus which outputs a stable signal for a long period of time with high mass productivity.

[0020]

According to a first aspect of the present invention, there is provided a position detecting apparatus comprising: an interferometer; and a leaf spring member fixed to the interferometer and capable of contacting the test object. Signal light emitted from the meter and based on the reflected light reflected by the leaf spring member;
An interference signal is obtained from a combined light beam with the reference light formed by the interferometer, the position information of the test object is detected from the interference signal, and the leaf spring member has a flat plate shape. It is characterized by being fixed to the interferometer at a fixed angle with respect to the light exit surface of the interferometer.

According to a second aspect of the present invention, in the first aspect of the present invention, a part of the leaf spring member is a reflection surface capable of contacting the test object, and the signal light is a light beam from the interferometer. The light is a light beam reflected by the reflecting surface.

According to a third aspect of the present invention, there is provided an information recording apparatus, wherein the position detecting device according to the first or second aspect is fixed to a rotary arm of a rotary positioner, and a magnetic head arm having a rotary axis of the rotary arm as a rotary axis; The leaf spring member is made contactable, the position information of the magnetic head arm is detected by the position detecting device, and a signal from the position detecting device is used.
The magnetic head arm is driven and controlled to record information on a hard disk and / or read information from the hard disk.

According to a fourth aspect of the present invention, a light beam from a light source is split into two light beams in a light transmitting member, and one of the light beams is reflected by a reflection surface outside the transmitting member facing the light transmitting member. An interference optical system that combines the reflected light with the other light beam in the transmitting member to obtain an interference light beam from the combined light beam, and a flat surface that is fixed to the interference optical system and that is not bent. Having a leaf spring-like member, and measuring the distance to the light reflecting surface provided on the leaf spring-like member with the interference optical system,
The method is characterized in that information on a distance to a test object in contact with the leaf spring-like member is measured.

According to a fifth aspect of the present invention, the position detecting device having the interferometer according to the fourth aspect of the present invention is attached to a rotary arm of a rotary positioner. The current of the voice coil of the hard disk drive is controlled so as to be constant, and the movement of the rotary positioner and the movement of the rotary arm are configured to interlock with each other. Each time the rotary positioner is positioned, a servo track signal is sent to the hard disk. Is written.

[0025]

FIG. 1 is a schematic block diagram of a first embodiment of an information recording apparatus having a servo track signal writing function according to the present invention. In the figure, the same members as those shown in FIG. 5 are denoted by the same reference numerals.

The hard disk drive HDD has a magnetic head arm ARM1 having a rotation axis O mounted outside the hard disk HD. Slider SLID attached to the tip of magnetic head arm ARM1
Is 0.5 μm facing the surface of the hard disk HD.
(Below), and moves in an arc by the rotation of the magnetic head arm ARM1.

The rotation of the magnetic head arm ARM1 is performed by applying a current to the voice coil motor VCM. As shown in FIG. 1, a position detection device NCPU, which will be described later, is spatially arranged at an appropriate position with respect to a hard disk drive HDD including a hard disk HD, a slider SLID, a magnetic head arm ARM1, a voice coil motor VCM, and the like.

SG is a signal generator for generating a servo track signal to be written to the hard disk HD.
This servo track signal is written to the hard disk HD via the magnetic head provided on the slider SLID.

Position detecting unit (position detecting device) NCP
U is provided on the support arm ARM2, the tip of the glass optical probe NCP is inserted into a slot-like opening (not shown) of the base plate of the hard disk drive HDD, and is disposed near the side surface of the magnetic head arm ARM1. It is shaped. The support arm ARM2 is arranged to be rotatable about a rotation axis coaxial with the rotation center O of the magnetic head arm ARM1.

The rotation position of the position detection unit NCPU is detected by a high-resolution rotary encoder RE attached to the rotation axis O of the support arm ARM2, and based on this detection data, a signal processor SP
1 rotationally drives the motor MO via the motor driver MD. With this form of feedback control, the position detection sensor unit NCPU is rotationally positioned.

Here, the position detecting unit NCPU is constituted by an optical sensor unit (interferometer) as described below.

FIG. 2 is an explanatory view of the configuration of an optical system for explaining an optical sensor unit (interferometer). The optical sensor unit includes a multi-mode laser diode LD, a non-polarizing beam splitter NBS, a probe-type polarizing prism PBS, a probe holder PHD, a reference reflecting surface M, and a 1/4.
It is composed of a wave plate QWP, a light beam diameter limiting aperture AP, a light beam amplitude dividing diffraction grating GBS, polarizing plates PP1 to PP4, photoelectric elements PD1 to PD4, and the like.

The divergent light from the multi-mode laser diode LD is converted into a gentle condensed light beam BEAM by a collimator lens COL, passes through a non-polarizing boom splitter NBS, and is then split by a probe-like polarizing prism PBS for each polarization component. The reflected S-polarized light beam is placed in a space about 300 μm away from the end face of the probe-like polarizing prism PBS, and is a leaf spring-like member SP fixed to the sensor unit.
Is irradiated near the beam waist.

The leaf spring-shaped member SP is in contact with the magnetic head arm ARM1 near the light beam irradiation point.
P is installed so as to have an appropriate spring property near the beam waist in the direction of the magnetic head arm ARM1. That is, when the leaf spring-like member SP approaches the magnetic head arm ARM1 and is pushed to the vicinity of the beam waist, the leaf spring-like member SP follows the movement of the magnetic head arm ARM1.

The reflected light returns to the original optical path as a diverging spherical wave, and returns to the probe-shaped polarizing prism PBS. On the other hand, the P-polarized light flux transmitted through the probe-shaped polarizing prism PBS is condensed and illuminated on the reflective evaporation film on the end surface at a position shifted from the beam waist, and the reflected light returns to the original optical path and returns to the probe-shaped polarizing prism PBS. It is. The wave optical path lengths of the two light beams are set to be substantially equal within the coherence distance of the light source.

For example, the shapes are given as follows. Probe-shaped polarizing prism PBS made of glass
Is about 2 mm, the light beam reflected by the polarizing prism PBS travels 1 mm in the glass, travels about 0.3 mm in the air from the light beam exit surface of the polarizing prism PBS, and the plate spring-shaped member SP Is illuminated on the reflective surface SPR.
Therefore, the reciprocating wave optical optical path length L1 from the polarizing prism PBS to the reflection surface SPR = (1 × 1.5 + 0.3) × 2
= 3.6. On the other hand, the light beam transmitted by the polarizing prism PBS travels 1.2 mm through the glass, and is illuminated on the glass end face. Therefore, the reciprocating wave optical optical path length L2 =
(1.2 × 1.5) × 2 = 3.6. Here, the refractive index of glass was set to 1.5.

Next, the focus position of the light beam (beam waist)
Is set at a position of 0.3 mm from the exit surface of the polarizing prism PBS. Then, the position of the wave source of the divergent spherical wave reflected from the leaf spring-shaped member SP and the reference reflection surface SPR appears to be shifted in the optical axis direction. Assuming that the inside of the probe-shaped polarizing prism PBS is viewed from the light source side, the leaf spring-shaped member SP
Is a focal point (wave source) of L1 ′
= (1 + 0.3 × 1.5) = 1.45.

The position of the diverging spherical wave source from the reference reflecting surface SPR is L2 '= 1.2 × 2-
It appears at the position of 1.45 = 0.95. However, both positions are visible in the glass. Therefore, the two divergent spherical wave sources are shifted by 0.5 mm in the glass, and when the two light beams are superimposed, the wavefronts do not completely match. Core-shaped interference fringes are obtained. In that case, if the phase of the wavefronts of both fluctuates due to the relative movement of the leaf spring-shaped member SP, concentric interference fringes appear to spring up or down from the center.

However, in this concentric circular interference fringe, since the amount of displacement of the two divergent spherical waves in the optical axis direction is as small as about 0.5 mm, a substantially one-color interference fringe portion at the center can be obtained widely. Therefore, an opening AP having an appropriate shape is provided so as to take out only one color part, and a part of the light beam is taken out. Thereafter, it can be treated as a substantially plane wave.

Now, the two light beams synthesized by the probe-shaped polarizing prism PBS are linearly polarized light beams orthogonal to each other, so that they do not actually interfere with each other to produce a bright / dark signal.
When the two light beams are reflected by the non-polarizing beam splitter NBS and pass through the quarter-wave plate QWP, the linearly polarized light that is orthogonal to each other is converted into circularly polarized light that is opposite to each other. The light is converted into one linearly polarized light that rotates due to a change in the phase difference between the two.

The rotating linearly polarized light is amplitude-divided into four light beams by a phase diffraction grating having a staggered grating structure. In other words, all light beams are completely equally divided in shape, intensity unevenness, defects, and other properties by amplitude division, so that even if the interference fringes are not one-color or the contrast is reduced for some reason, the effects of all are equal. .
In particular, the reflected light from the leaf spring-shaped member SP is disturbed in the wavefront due to the minute uneven structure, and the intensity unevenness is strong. However, the wavefronts of the four light fluxes have the same disorder and the intensity unevenness is equal.

The luminous fluxes divided into four are arranged such that the polarization directions thereof are shifted from each other by 45 degrees.
By passing through PP1 to PP4, the light / dark timing is converted into interference light having a phase shifted by 90 degrees. The lowering of the contrast due to the influence of wavefront disturbance and intensity unevenness is all equally affected. Each light and dark luminous flux is transmitted to each light receiving element P
Light is received by D1, PD2, PD3, and PD4.

The signals of the light receiving element PD1 and the light receiving element PD2 having a phase difference of 180 degrees are differentially detected, and the DC component (contrast reduction due to wavefront disturbance or the like) is almost removed to obtain an A-phase signal.

Similarly, the signals of the light receiving elements PD3 and PD4 having a phase difference of 180 degrees from each other are differentially detected.
DC component (contrast reduction due to wavefront disturbance, etc.)
Is substantially removed, and the signal is regarded as a B-phase signal. The A and B phase signals have a phase difference of 90 degrees from each other, and the Lissajous waveform observed by the oscilloscope is circular. The amplitude (the size of the circle) of the waveform of the Lissajous fluctuates due to the minute unevenness of the leaf spring-shaped member SP, but the center position does not fluctuate. Therefore, essentially no error occurs in phase detection (measurement of relative distance).

Further, by condensing and illuminating the leaf spring-shaped member SP, the influence of a change in the interference state (one-color deviation) due to a relative angle deviation (alignment deviation) of the leaf spring-shaped member SP is avoided. In other words, by condensing illumination, even if there is a misalignment, the main emission direction of the divergent spherical wave is only slightly shifted, and the vignetting of the spherical wave itself is avoided,
Further, since the overlapping state of the wavefronts of the two divergent spherical waves does not change, the interference state can be stably obtained.

Therefore, it operates as an interference-type position detection sensor that does not require adjustment between the head arm side surface ARM1 and the illumination light beam and is very easy to handle.

Although the illumination position shift (parallel shift) does not contribute to the phase shift of the divergent spherical wave, the interference signal amplitude fluctuates due to a minute change in the unevenness of the leaf spring-like member according to the illumination position.

However, since the center position of the Lissajous waveform does not fluctuate, essentially no error occurs in phase detection.

Head arm ARM1 and position detection sensor N
The positional relationship of the CPU changes with the deformation of the leaf spring-shaped member SP, and an angular shift and a parallel shift occur. Light source L
Assuming that D is a multimode laser, the coherence length is about 100 μm. That is, the possible range of the position detection is about 50 μm. However, as described above, if the reflected light from the leaf spring-shaped member SP of the subject is guided to the sensor, even if an alignment shift or a parallel shift occurs, essentially no problem occurs.

The signal finally detected is a sinusoidal signal whose period is half the wavelength of the light source, since the principle of the measurement is the interference length measurement using the reciprocating optical path. Wavelength 0.78μ
When a laser diode that emits a light beam of m is used, a sine wave signal having a cycle of 0.39 μm is obtained, and the relative distance fluctuation can be detected by counting the wave number. Furthermore, since two phases of a sine wave signal having a phase difference of 90 degrees are obtained, the relative position shift with finer resolution can be detected by electrically dividing the signal with a known electric phase dividing device.

If it is electrically divided into 4,096, the relative positional deviation can be detected with a minimum of 0.095 nm. If a current is applied to the head arm drive motor (voice coil) VCM with an appropriate control device so that the relative position shift becomes zero, the relative position can be stably maintained at about several times of ± 0.095 nm (servo control). Call).

A high-precision rotary positioner RTP which has a built-in rotary encoder RE for generating a signal of 81000 sine waves / rotation and can be divided into 2048 positions.
Is used, the position detection sensor NCPU attached near the side surface of the head arm ARM1 having a radius of 30 mm is ±
Positioning can be performed with a resolution several times that of 1.4 nm.

Since the relative position stabilization of the position detection sensor itself is about several times of ± 0.095 nm as described above, the positioning resolution combining the two is about the performance of the high-precision rotary positioner RTP itself.

As described above, the position detection sensor NC
Servo that keeps the position of the end surface of the head arm ARM1 constant through PU, a high-precision rotary positioner RTP
By adding to the above, stable positioning accuracy could be obtained without adding disturbance to the high-precision positioner.

Here, the leaf spring-like member SP, which is a feature of the present invention, will be described with reference to FIGS. As described above, the plate spring-shaped member SP is provided with the light reflecting surface SPR, and the light beam is condensed at a position where the measurement light and the reference light have the same optical path length as described above.

FIGS. 3 and 4 are views for explaining how the leaf spring-shaped member SP used in the present invention contacts the subject (ARM1 in this embodiment). Glass optical probe N in the figure
The CP is provided with an inclined portion such as a hatched portion, and a flat leaf spring member SP that is not bent is fixed to the inclined portion as a mounting surface of the leaf spring-shaped member SP. FIG. 4A shows a state in which the magnetic head arm ARM1 is not in contact with the leaf spring-shaped member SP. At this time, the leaf spring SP is inclined with respect to the contact surface of the head arm ARM1 by the angle of the inclined portion. FIG. 4B shows a state in which the head arm ARM1 has hit the leaf spring-shaped member SP, and FIG. 4C shows a state in which the leaf spring SP abuts and deforms.

When the measurement light and the reference light have the same optical path length, that is, at the position where the maximum interference signal can be obtained,
The leaf spring SP is perpendicular to the measurement light beam.
Assuming that the deformed portion of the spring is a leaf spring having the same width, FIG.
As shown in (C), the deformation of the spring is formed as a fan shape at a point B, with the spring mounting surface having an angle provided on the glass optical probe NCP being tangent.

In the present embodiment, when the leaf spring-shaped member SP is deformed to the optimum measurement position, a tangent line is formed at points B and A in the direction perpendicular to the mounting surface of the leaf spring-shaped member SP and the measurement light beam, respectively. I have it. If a leaf spring-like member having a bent process is used, the optical reflection surface of the leaf spring-like member is perpendicular to the measurement light beam at the optimum measurement position due to processing tolerance and settling of the bent portion of the spring. However, by providing the spring mounting surface and the spring shape as described above, stable measurement can be performed even when a plate spring-like member having low processing shape stability is used as the test surface. .

Further, since there is no bent portion of the spring, there is very little change in the diameter of the spring shape and little set, and stable measurement can be performed.

As described above, in the present embodiment, the position measuring device NCPU is fixed to the support arm ARM2 of the rotary positioner RTP, and the leaf spring-like member SP which makes elastic contact with the side surface of the magnetic head arm ARM1 is attached to the position measuring device NCP.
U to the glass optical probe NCP, and the position measuring device N is attached to the light reflecting portion SPR provided on the leaf spring-shaped portion SP.
By irradiating a light beam from the CPU, taking out the reflected light and making it interfere with other light beams, the position information of the leaf spring-shaped member SP is measured. , The relative distance to the position measurement device NCPU provided in the magnetic head arm ARM1 is controlled and driven so that the measured value becomes constant.

Thus, a position detecting device having high productivity and suitable for a manufacturing apparatus is provided. In addition, the fixed surface of the leaf spring-like member of the position detection device has a certain angle,
A flat spring-shaped member without bending or the like is fixed there, and position information is measured with high accuracy.

In the present embodiment, the position detecting unit NCPU which receives the interference light and detects the relative displacement between the magnetic head arm ARM1 and a part of the interferometer of the position detecting unit (position detecting device) NCPU is rotated and positioned. Rotary arm (support arm) AR of device (rotary positioner)
M2, the current of the head arm drive motor (voice coil) VCM of the hard disk drive HDD is adjusted so that the output from the position detection unit NCPU becomes constant with respect to the fluctuation of the position of the rotary positioning device (rotary positioner) RTP. Control, the movement of the rotary positioner RTP and the movement of the magnetic head arm ARM1 are linked to each other.
The servo track signal is stably written to the hard disk HD every time the positioning is performed.

In the present embodiment, the interference system is fixed to the interference system.
The leaf spring-like member is a flat plate (flat plane) without bending, and is fixed to a fixed surface provided at a fixed angle in the position detection unit. Then, the distance from the interferometer to the light reflecting surface SPR provided on the leaf spring-like member SP is measured, and the distance from the magnetic head arm ARM1 in contact with the leaf spring-like member or the plate-like member is measured.
Thus, the servo signal of the hard disk drive is written.

The following effects are obtained in the above embodiment.

(A-1) Since the side surface of the head arm is measured in contact with a leaf spring-like member, the versatility is higher than the interferometric length measurement method using a corner cube, and a special optical element or the like is provided on the hard disk side. No need to add.

(A-2) Since an equal optical path length interference system is used, the accuracy is relatively high even under temperature fluctuations as compared with the interferometric length measurement method using a corner cube.

(A-3) Most of the interference light path is a common light path, and most of the light path after division is also in the glass, so that the accuracy is less reduced due to environmental fluctuation.

(A-4) Since the leaf-spring-like member is not bent, a stable position detecting device can be mass-produced with extremely little variation in shape error due to processing accuracy.

(A-5) A stable signal can be obtained for a long period of time without any change in the shape of the leaf spring-shaped member with time or settling.

In particular, according to the above arrangement, the leaf spring-like member is brought into contact with the magnetic head arm, and the distance between the reflection surfaces provided on the leaf spring-like member is measured by an interference system, so that the magnetic head is indirectly measured. The distance between the arm and the sensor probe can be measured indirectly. At this time, the NCP probe is provided with a spring fixing surface with a certain angle, and by using a flat leaf spring without bending, the processing accuracy does not affect the measurement signal output, and the shape change over time can be prevented. Since there is no signal, it is possible to obtain a stable signal for a long time.

This makes it possible to easily mass-produce a high-precision position measuring device irrespective of the surface to be inspected, and to guarantee the output of the sensor for a long period of time.

[0072]

According to the present invention, by setting each element as described above, it is not necessary to provide a special member on the object side, and the position of the object can be determined with high reliability and high accuracy. Thus, it is possible to achieve a position detecting device, an interferometer, and an information recording device using the same, which can detect the position of the object and position the object.

Further, according to the present invention, it is possible to achieve a position detecting device and an interferometer suitable for a manufacturing device which has high productivity and outputs a stable signal for a long time.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram illustrating a servo track signal writing device according to a first embodiment of the present invention.

FIG. 2 is an explanatory view of an optical non-contact distance sensor unit of the servo track signal writing device shown in FIG. 1 and a detailed view of a probe holder.

FIG. 3 is a schematic configuration diagram of a glass probe portion of a characteristic sensor of the servo track signal writing device according to the embodiment of the present invention.

FIG. 4 is a detailed explanatory view of a leaf spring-like member of the servo track signal writing device according to the embodiment of the present invention.

FIG. 5 is an explanatory diagram of a conventional hard disk drive device and a servo track signal writing device using a push rod.

FIG. 6 is an explanatory diagram of a conventional servo track signal writing device using a hard disk drive device and a retroreflector interferometer.

[Explanation of symbols]

NCPU Optical non-contact sensor unit NCP Optical probe (Light guide member) NBS Non-polarized beam splitter PBS Polarized prism film M Reflective film LGT Light source LD Laser diode COL Collimator lens PD Light receiving element PP Polarizing plate G Transparent substrate QWP quarter wave plate SLID Magnetic Head Slider ARM1 Magnetic Head Arm (Rotating Member) ARM2 Rotary Positioner Arm (Rotating Member) RTP Rotary Positioner RE Rotary Encoder MO Motor MOD Motor Driver VCM Magnetic Head Arm Rotating Motor (Voice Coil) VCMD Voice Coil Motor Driver HD Hard disk (recording medium)

Claims (5)

[Claims] 1. An interferometer, and a leaf spring member fixed to the interferometer and capable of contacting the object to be inspected, emits light from the interferometer and reflects light reflected by the leaf spring member. Signal light, and an interference signal is obtained from a combined light beam of the reference light formed by the interferometer, and the position information of the object to be detected is detected from the interference signal. A position detection device fixed to the interferometer at a fixed angle with respect to the light emission surface of the interferometer. 2. A method according to claim 1, wherein a part of said leaf spring member is a reflecting surface capable of contacting said test object, and said signal light is a light beam from said interferometer reflected by said reflecting surface. The position detecting device according to claim 1, wherein: 3. The position detecting device according to claim 1, which is fixed to a rotating arm of a rotary positioner, so that a magnetic head arm having a rotating shaft of the rotating arm as a rotating shaft can contact the leaf spring member. The position detection device detects the position information of the magnetic head arm, and uses the signal from the position detection device to drive and control the magnetic head arm to record information on a hard disk and / or An information recording device for reading information from a device. 4. A light beam from a light source is split into two light beams in a light transmitting member, and one of the light beams is reflected by a reflection surface outside the transmitting member facing the light transmitting member, and the reflected light is reflected by the light transmitting member. The plate has an interference optical system that multiplexes the other light beam in the transmission member and obtains an interference light beam from the combined light beam, and a plate spring-shaped member fixed to the interference optical system and that is a flat plate. An interferometer, wherein a distance to a light reflecting surface provided on a spring-like member is measured by the interference optical system, and distance information to a test object in contact with the leaf spring-like member is measured. 5. A hard disk drive having a position detecting device having the interferometer according to claim 4 attached to a rotary arm of a rotary positioner so that the output from the position detecting device becomes constant with respect to a change in the position of the rotary positioner. The current of the voice coil of the apparatus is controlled so that the movement of the rotary positioner and the movement of the rotary arm are linked, and a servo track signal is written to the hard disk every time the rotary positioner is positioned. Information recording device.