JPH04276503A - Position-detection setting mechanism - Google Patents

Abstract

PURPOSE:To facilitate assembling and adjustment with a compact configuration and to make it possible to determine a position highly accurately. CONSTITUTION:An arm 4 is attached to a driving shaft 3 of an actuator 2. A head part 5 and a scale 7 are fixed to both ends of the arm 4, respectively. An optical sensor head 8 which is fixed to the main body of an apparatus is slidably engaged with the scale 7. The relative positions of the head part 5 which is moved with the actuator 2 and a recording medium 1 are precisely determined with the optical sensor head 8.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention relates to an apparatus for recording and reproducing information on a recording medium such as a floppy disk, hard disk, optical disk, magneto-optical disk, or optical card.
The present invention relates to a position detection and setting mechanism that detects and sets a relative position between a head unit for recording and reproducing information and the recording medium.

0002

2. Description of the Related Art In the above-mentioned recording and reproducing apparatus, a conventional position detection and setting mechanism mainly detects and determines the relative position between a tracking position formed on a recording medium and a head section. It consisted of a scale that moves relatively in conjunction with the movement of the scale and a scale reading sensor head. In other words, the amount of movement of the head unit or recording medium is converted into the amount of movement of the scale or scale reading sensor head, the relative position is detected by detecting this amount of movement, and the actuator unit is controlled to come to the target relative position. This determines the position.

0003

[Problems to be Solved by the Invention] In the above-mentioned recording/reproducing apparatus, the distance between the tracks is becoming narrower and narrower as the recording density of the recording medium becomes higher. On the other hand, there is a growing demand for smaller and thinner devices. However, conventional position detection and setting mechanisms have low detection accuracy and low resolution, so small position changes must be magnified by a lever mechanism or the like and then detected by a reading sensor head. For this reason, there was a problem in that the device became larger. Also,
In order to improve detection accuracy, the assembly precision of the mechanism must be increased, which also poses the problem of requiring time and effort to make adjustments.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a position detection and setting mechanism that is small in size, easy to assemble and adjust, and capable of highly accurate positioning.

[0005]

[Means for Solving the Problems] The position detection and setting mechanism of the present invention includes a recording medium for recording information, a head unit for recording/reproducing or erasing information on the recording medium, and a relative position between the recording medium and the head unit. In a position detection and setting mechanism that includes an actuator unit that controls position and a detection unit that detects relative position or relative movement amount, the detection unit includes a scale that displays the position of the head unit and an optical sensor that optically reads the scale. The present invention is characterized in that one of the scale and the optical sensor head is fixed to the apparatus main body, and the other is fixed to a moving member on which the head section is mounted and driven by an actuator section.

[0006] Furthermore, the scale and the optical sensor head are held in a slidably elastic contact state.

[0007]

[Operation] In the position detection and setting mechanism configured as described above, when the head section fixed to the movable member is moved by the actuator section, the scale fixed to either the movable member or the device body and the scale fixed to the other The optical sensor head moves relative to the optical sensor head. Therefore, by reading the scale with the optical sensor head, the position of the head can be detected and determined.

Furthermore, by bringing the scale and the optical sensor head into elastic contact, the distance between the scale and the optical sensor head can be kept extremely close and always constant without being affected by distortion or vibration of the scale. can. As a result, it is possible to downsize the device, facilitate assembly and adjustment, and improve positioning accuracy.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

A first embodiment of the present invention is shown in FIGS. 1 and 2. In FIG. 1, a recording medium 1 such as a floppy disk is placed and held on a rotating table (not shown). Further, the main body of the apparatus is provided with an actuator 2, and an arm 4, which is a moving member, is attached to a drive shaft 3 of the actuator 2. A head section 5 such as a magnetic head is mounted on one end of the arm 4.
The head portion 5 moves along a track 6 formed on the recording medium 1 by the rotation of the recording medium 1 and the rotation of the recording medium 1 . Then, the head section 5 records and reproduces information on the recording medium 1.

An arc-shaped scale 7 centered on the drive shaft 3 of the actuator 2 is fixed to the other end of the arm 4, and an optical sensor head 8 fixed to the main body of the device can slide on the scale 7. is engaged with. FIG. 2 shows the configuration of the optical sensor head 8. The optical sensor head 8 includes a light source 12 such as a light emitting diode in a casing 11 whose bottom surface is open.
and a built-in light receiving element 13 such as a phototransistor,
Index scale 14 on the bottom opening of the casing 11
is fixed. The index scale 14 is
For example, on the lower surface of the transparent plate 15 made of glass or synthetic resin,
Transparent portions 16 and non-transparent portions 17 are repeatedly formed at a constant pitch. The transparent portion 16 may be formed in the shape of a slit in the opaque plate by etching or the like.

[0012] On the upper surface of the casing 11, the lower surface of an upper elastic arm 19 of an elastic holding member 18 formed of, for example, synthetic resin into a substantially U-shape is fixed. Further, the elastic holding member 18 is fixed to the substrate of the main body of the apparatus via a support member (not shown). Further, an arm 4 is provided between the lower elastic arm 20 of the elastic holding member 18 and the optical sensor head 8.
A scale 7 fixed to is elastically held, and the scale 7, the index scale 14, and the lower elastic arm 20 are in slidable elastic contact with each other.

The scale 7 has a pattern layer 22 made of a highly reflective material formed on the surface of a plate 21 made of transparent glass or synthetic resin in an arc shape by a method such as vapor deposition or printing. The portion 23 and the opaque high reflectance portion 24 are repeated at a constant pitch. This pitch is equal to the pitch between the transparent part 16 and the non-transparent part 17 formed on the index scale 14.

Next, the operation of this embodiment will be explained. The arm 4 is rotated by the actuator 2, and the head portion 5 is rotated as shown in FIG.
When the drive shaft 3 is moved in the direction of arrow A-B as shown in
The scale 7 on the opposite side moves in the direction of arrow CD. At this time, if the transmitting section 16 of the index scale 14 and the high reflectance section 24 of the scale 7 match, the light emitted from the light source 12 passes through the transmitting section 16 and passes through the high reflectance section. 24 and enters the light receiving element 13. On the other hand, when the transmitting section 16 of the index scale 14 and the low reflectance section 23 of the scale 7 match, the light emitted from the light source 12 passes through the transmitting section 16 and the low reflectance section 23. However, almost no light enters the light receiving element 13.

Therefore, when the optical sensor head 8 and the scale 7 move relative to each other, the signal intensity output from the light receiving element 13 changes, for example, in the form of a triangular wave. The relative displacement of the optical sensor head 8 with respect to the scale 7 can be determined. When this amount of displacement reaches a predetermined amount, the rotation of the actuator 2 is stopped and positioning is performed.

At this time, the index scale 14 and the scale 7 are in contact with each other or are very close to each other, and the distance between the two scales 7 and 14 is kept constant, so the influence of interference is reduced and the light receiving element The waveform of the light reception signal outputted from 13 does not become dull or fluctuate unstablely, and the accuracy of displacement measurement can be improved. In addition, Thrale 7 and Index Scale 14
The pitch of the positioning mechanism can be reduced, and the resolution of the positioning mechanism can be increased to, for example, several tens of micrometers or less.

In the above embodiment, a case was explained in which the scale 7 was fixed to the arm 4 and the optical sensor head 8 was fixed to the main body of the apparatus, but conversely, the scale 7 was fixed to the main body of the apparatus and the optical sensor head 8 was fixed to the arm 4. It may be fixed to 4. According to this mechanism, the optical sensor head 8 can be made lightweight, so the load on the actuator 2 can be reduced, and high-speed positioning is possible.

Further, the shape of the scale 7 is not limited to an arc shape, but may be a straight shape.

FIG. 3 shows a second embodiment of the invention. Figure 3
In this embodiment, parts corresponding to those in the first embodiment shown in FIG. 1 are denoted by the same reference numerals, and the explanation thereof will be omitted as appropriate. In this embodiment, an actuator 31 that moves linearly is provided to the main body of the device, and a head portion 5 is provided at the tip of the actuator 31.
It is equipped with. The moving direction of the actuator 31 is a direction passing through the center of the recording medium 1, as shown by arrow EF, and the optical sensor head 8 is fixed to the actuator 31. Further, a linear scale 32 fixed to the device main body is provided along the actuator 31, and the optical sensor head 8 is slidably engaged with the scale 32 as in the case of the first embodiment. ing. Further, the configurations of the optical sensor head 8 and the scale 32 are similar to those shown in the first embodiment.

According to this embodiment as well, the same operational results as in the first embodiment can be obtained.

Alternatively, as shown in FIG. 4, the scale 32 may be fixed to the actuator 31 and the optical sensor head 8 may be fixed to the main body of the apparatus.

Furthermore, the actuator 31 may be fixed to the main body of the apparatus, and the head portion 5 may be mounted on a slider (not shown) driven by the actuator 31.

[0023]

[Effects of the Invention] As explained above, according to the position detection and setting mechanism of the present invention, the position of the head section driven by the actuator section is detected by the detection means consisting of the scale and the optical sensor head. Therefore, the relative position or relative movement amount between the recording medium and the head section can be detected with high precision. Further, by bringing the scale and the optical sensor head into slidable and elastic contact, the position detection and setting accuracy can be further improved.

[Brief explanation of the drawing]

FIG. 1 is a plan view showing a main part of the configuration of a first embodiment of a position detection and setting mechanism of the present invention.

FIG. 2 is a longitudinal cross-sectional view showing the configuration of the optical sensor head in FIG. 1;

FIG. 3 is a plan view showing a main part of the configuration of a second embodiment of the position detection and setting mechanism of the present invention.

FIG. 4 is a plan view showing a main part of a configuration of a modification of the second embodiment shown in FIG. 3;

[Explanation of symbols] 1 Recording medium 2,31 Actuator 5 Head part 7,32 scale 8 Optical sensor head (detection means)

Claims (2)

[Claims] 1. A recording medium for recording information, a head unit for recording/reproducing or erasing information on the recording medium, an actuator unit for controlling the relative position of the recording medium and the head unit, and a A position detection and setting mechanism equipped with a detection means for detecting a position or relative movement amount, wherein the detection means is composed of a scale for displaying the position of the head section, and an optical sensor head for optically reading the scale, and A position detection and setting mechanism, characterized in that one of the scale and the optical sensor head is fixed to an apparatus main body, and the other is fixed to a moving member on which the head section is mounted and driven by the actuator section. 2. The position detection and setting mechanism according to claim 1, wherein the scale and the optical sensor head are held in a slidably elastic contact state.