JPS62277673A - Disk position detector in disk recording and reproducing device - Google Patents

Abstract

PURPOSE:To improve both reliability and accuracy and to reduce the cost by detecting accurately the head reference position via a pressure sensor unified with a head and allowing a sensor element of conductive rubber to perform the switching operations in response to the change of pressure resistance. CONSTITUTION:A carriage 7 is moved toward a pressure sensor unit 13 and a part 7a of the carriage 7a comes into impact contact with a pressure element 17 of the unit 13. Thus an operating barrel part 17a of the element 17 is pressed by the part 7a and moved gradually into a housing 16 while compressing a coil spring S1. When the element 17 is pushed into the housing 16 up to a minute space (g) formed between the element 17 and the conductive rubber 15, an active cylinder part 17b of the element 17 starts pushing the rubber 15. This pressing force is increased in proportion to the shift value of the element 17 and the output voltage of the rubber 15 drops in a process where the addition of the compression force of the spring S1. As a result, the working voltage V drops and a control circuit 22 reacts.

Description

[Detailed Description of the Invention] 3. Detailed Description of the Invention (Field of Industrial Application) This invention relates to processing by recording or reproducing various information using disks of computers, word processors, electronic game machines, electronic musical instruments, etc. The present invention relates to a disc position detection device in a disc recording and reproducing device.

[Conventional technology]

Conventional disc position detection devices for this type of disc recording/playback equipment are (a) a method using a mechanical switch;
b) A method using an optical switch is mainly known.

By the way, in method (a), a disk is inserted into its insertion section, and a recording/reproducing element such as a head moves radially over the disk together with a carriage equipped with this element to a standby position. When the carriage is controlled, it is detected by a mechanical means such as a switch that the carriage has moved to the reference position, and the movement of the carriage is stopped by stopping the drive of the motor, so that the recording/reproducing element is always in an accurate standby state. can be regulated.

In the method (0), the means for detecting the reference position of the recording/reproducing element that can move in the radial direction on the disk inserted into the insertion section is a pair of phototransistors, LEDs, etc. It consists of a light-emitting body and a light-receiving body,
It is formed as an optical switch that always irradiates light in a certain direction, and a part of the carriage equipped with the recording/reproducing element detects the position by blocking the optical path of the optical switch, and the stiffness causes the recording/reproducing element to detect the position. By accurately detecting the reference position of the element and stopping the drive of the motor, movement of the carriage can be stopped and the standby state of the recording/reproducing element can be correctly regulated.

[Problem that the invention seeks to solve]

Among the conventional methods described above, method (a) has the advantage of being cheap and simple in structure, but it lacks reliability and accuracy, tends to cause chattering, and has the problem of adversely affecting the control circuit. However, the (II+) method has the advantage of relatively high reliability and accuracy;
They have drawbacks such as being expensive, consuming large amounts of power, and being easily influenced by external light, which can cause malfunctions.

[Means for solving problems]

This invention was made with attention to the above points, and the present invention is based on the fact that a pressure sensor made of conductive rubber material is inexpensive, has extremely high reliability and accuracy, does not cause chattering, and can be used for various types of recording and reproducing using a disk. Through repeated and detailed research, we confirmed that it is possible to accurately detect the moving position of a carriage equipped with a recording/reproducing element and driven by a motor in industrial equipment, and we also used this conductive rubber material as a type of switch mechanism. The pressure sensor unit is fixed on the carriage or at a position isolated from the carriage, and has a structure in which pressure is controlled by movement of the carriage driven by a motor, and position detection and reference position regulation are performed electrically. .

On the other hand, since the carriage requires precise positional movement,
The operating force of the pressure sensor unit is required to be very small.

The pressure sensor unit is also configured to connect to existing motor control circuits.

(Function) When a desired disc is inserted into the insertion section of a desired recording/reproducing device and start control is performed, the recording/reproducing element such as the head will start.
It moves in the radial direction on the disk together with the carriage, and when the carriage moves at the reference position, an external force acts on the pressure sensor unit, and the conductive rubber material used as the pressure sensor deforms, causing the output resistance value to change, and the resistance value to remain constant. When it detects that the value has been reached, the drive motor is stopped and the movement of the ridge is stopped with key. The stop position of this carriage is the first reference position of the recording/reproducing element.

This allows the recording/reproducing element to obtain an accurate standby state on the disk.

(Example) This invention will be described below with reference to FIGS. 1 and 2.
, D, D, that is, floppy disk drive device A
We will explain the case where it is implemented.

These FIGS. 1 and 2 show the basic schematic structure of F, D, and D, and first, the structure and basic operation will be explained.

Reference numeral 1 indicates a desired floppy disk, which is rotatably housed in a rectangular case 2. 3 is a pulse motor fixed to the main body 4, and a feed screw 6 is attached on the extension of the rotating shaft 5.
are directly connected. A carriage 7 is screwed onto the feed screw 6, and a magnetic head 8 is fixed to the tip of the carriage 7.

That is, when the pulse motor 3 rotates, the feed screw 6 rotates, and the carriage 7 can be moved back and forth along the feed screw 6.

Reference numeral 9 denotes an insertion section opened in the main body 4 into which the floppy disk 1 can be inserted together with the case 2, and a motor (not shown)
The rotation of the drive shaft 11, which engages with the center hole 10 of the floppy disk 1 in the case 2, causes the magnetic head 8 to come into contact with a regulated position (referred to as a track) #1 on the circumference. #2. Annular magnetic recording or magnetic reproduction can be performed in .

Reference numeral 12 indicates a guide for guiding the movement of the carriage 7, and reference numeral 13 indicates a pressure sensor unit provided at a location where the part 7a of the carriage 7 can approach and separate, and has the function of detecting the reference position of the carriage 7.

Next, the pressure sensor unit 13 will be explained in detail below.

First, to explain the configuration of FIG. 3, 14 is an electrode P
1, a circuit board with P2, and 15 is a conductive rubber as a pressure sensor attached on the substrate 14, and is a rubber material formed by uniformly dispersing desired conductive particles, such as carbon particles. When the carbon particles are compressed under a desired pressure, the distance between the carbon particles becomes closer, the electrical conductivity increases as the pressure increases, and the electrical resistance decreases. When the pressure is released, it returns to its original shape,
Electrical resistance also returns to its initial value.

Reference numeral 16 denotes a hollow casing formed by maintaining the laminated state of the substrate 14 and the conductive rubber 15, through which a double-structured presser 17 is inserted, and a coil spring S1 is inserted between the casing 16 and the presser 17. is interposed between the housing 1 and the presser 17 at all times.
6, it functions so that it can move outward. The presser 17 is formed by an operation cylinder part 17a that protrudes to the outside of the housing 16, and an operation cylinder part 17b that is inserted into the operation cylinder part 17a and comes into contact with and separates from the conductive rubber 15. A compression coil spring S2 is provided in the portions 17a and 17b.
The operating cylindrical portion 17a can be engaged with the housing 16 through the flange 18, and the operating cylindrical portion 17b can be engaged with the step 20 on the inner wall of the operating cylindrical portion 17a through the flange 19. ing.

Furthermore, the tip of the actuating cylindrical portion 17b of the presser 17 on the opposite side from the flange portion 19 is disposed so as to be able to come into contact with and separate from the conductive rubber 15 with a small distance g therebetween.

Note that in the pressure sensor unit 13, reference numeral 21 indicates a lead wire taken out from the circuit board 14.

Next, the operation will be explained based on the above configuration.

The carriage 7 moves to the pressure sensor unit 13 side, and a part 7a is pressed against the presser 17 of the pressure sensor unit 13.
When the pusher 17 collides with the pusher 17, its operation cylinder portion 17a is pressed by the part 7a of the carriage 7, and the pusher 17 is gradually pushed into the housing 16 while compressing the coil spring S.

Then, the minute distance g between the presser 17 and the conductive rubber 15
When the presser 17 is pushed into the housing 16 to a distance of
This conductive rubber 15 begins to be pressed.

By the way, the acting force P applied to the presser 17 by the part 7a of the carriage 7 and the movement ff1X of the presser 17
As shown in the graph in FIG. ) Position to start moving...
・・・・・・・・・・・・・・・・・・・・・A(b)
Position in contact with conductive rubber 15...
・B (8) Position where coil spring S2 starts operating...
-C, the acting force PC increases in proportion to the amount of movement of the presser 17, that is, the amount of displacement g, and as the compressive force of the coil spring S2 starts to be added, as shown in FIG. Since the upper voltage of VC decreases, a drop phenomenon of the working voltage (2) occurs, and the control circuit 22 reacts when the working voltage is at VC.

The point at which the presser 17 reaches this operating voltage VC is the reference position of the carriage 7, and at the same time corresponds to the reference position of the magnetic head 8.

Therefore, if the operating state of the pressure sensor unit 13 is electrically connected to the control circuit 22 shown in FIG. Rotate the feed screw 6 to
The magnetic head 8 of the carriage 7 is moved by this feed screw 6.
It can be moved along the radial direction on the floppy disk 1 to a predetermined position.

After the pressure sensor unit 13 detects the reference position, the compression on the conductive rubber 15 inside the pressure sensor unit 13 is released by the reverse control of the pulse motor 3, so that the initial Of course, it is possible to return to the original state.

Here, the control circuit 22 is for controlling the drive of the pulse motor 3 to move the carriage 7, and may have a conventionally known circuit configuration.

Similarly, for the movement mechanism of the carriage 7, a conventionally commonly used mechanism other than the one shown in FIG. 1 may be used.

Furthermore, if there is a small distance g between the tip of the actuating cylindrical portion 17b and the conductive rubber 15, the reference position of the carriage 7 can be controlled by adjusting g, so that a more accurate reference position can be achieved. If a pulse motor whose operation is digitally controlled by pulses, such as a stepping motor, is used as the drive motor 3, it is also possible to use the drive motor 3 with the tip of the actuating cylindrical portion 17b in contact with the surface of the conductive rubber 15. be.

Next, a pressure sensor unit 13A of another embodiment will be explained based on FIG.

Similarly to the pressure sensor unit 13 described above, the conductive rubber 15 and the electrode P1. A circuit board 14 having P2 is attached,
Opposing the conductive rubber 15, a shaft 23 is rotatably mounted at one end.
an operating pusher 24b attached to the operating pusher 24b;
The circuit board 1 is mounted on the shaft 23 so as to move independently of the circuit board 1.
4 and the operation pusher 24a with a coil spring S1 interposed therebetween.
are configured via a coil spring S2.

When the part 7a of the carriage 7 comes into contact with the operation pusher 24a and rotates about the shaft 23 against the coil spring S, the operation pusher 24b comes into contact with the conductive rubber 15, and the operation is repeated as in the embodiment described above. By a similar effect, the electrode P+ on the substrate 14
, P2, the reference position of the carriage 7, that is, the magnetic head 8 can be accurately regulated.

Next, another pressure sensor unit 13B will be further explained with reference to FIG.

In this embodiment, the conductive rubber 15 is pressed by the presser 25, and the electrode P1. Both electrodes ρ3. This shows a case in which p2 is kept energized and the configuration is opposite to that of the above embodiment, in which a pressing force is applied to the presser 25 by a pressing spring 27 that is supported by a shaft 26 and wound around the shaft 26. It is something that

Therefore, if the part 7a of the carriage 7 equipped with the magnetic head 8 comes into contact with the presser 25 and rotates it in the opposite direction about the shaft 26 against the pressure spring 27, the conductive rubber 15 The pressure acting on the conductive rubber 15 gradually decreases, and in the process of the conductive rubber 15 returning to its original shape, the output resistance value increases.
Finally, it becomes non-conductive, exhibiting a switching action, and as a result, the reference position of the carriage 7 can be detected, and the magnetic head 8 can be accurately stopped at the starting position to obtain a so-called standby state.

In the above-described embodiments, some of the pressure sensor units are illustrated, but as the simplest structure, the part 7a of the carriage 7 may be directly brought into contact with and separated from the conductive rubber 15. The pressure sensor unit may be attached directly to the

Broadly speaking, the relationship between the electrode and the conductive rubber is, of course, not only when they are adjacent to each other as in the above example, but also when different electrodes are placed on both sides of the conductive rubber, or when one electrode and the conductive rubber are placed next to each other. The rubber may be placed adjacent to each other and the other electrode may be included in a portion 7a of the carriage 7, and the structure does not need to be particularly specified.

Next, an example of the relationship between the output resistance value of the conductive rubber 15 for a pressure sensor with φ=3.4 mm and t=0.7 mm and the pressing force is shown in a graph in FIG. 10.

The electrodes used at this time were as follows.

According to the graph, all electrodes have a pressing force of 20 gr to 40 gr.
It can be seen that the output resistance value decreases in proportion to the pressure in the low pressure range of . can be adjusted using a coil spring.

In the above embodiments, only F, D, and D disks are targeted, but the present invention can be similarly applied to other disk types that can be recorded and reproduced by means other than magnetism, such as a laser.

〔Effect of the invention〕

According to this invention, the reference position of the head with respect to the disk is accurately determined by a pressure sensor unit that detects the position of the carriage integrated with the head, and the sensor element made of a conductive rubber material detects a change in pressure resistance. Since it performs a type of switching operation using a special electrical change, it is highly reliable, highly accurate, and inexpensive, making it highly useful in a wide range of disk drive devices.

[Brief explanation of the drawing]

FIG. 1 and FIG. 2 are an explanatory plan view of the main structure of an embodiment of a disk position detection device in a disk recording and reproducing device according to the present invention, and a plan view of a floppy disk;
FIG. 3 is a sectional view showing an example of the pressure sensor unit according to the present invention, FIG. 4 is a plan view showing an example of the electrode structure of the substrate used in the pressure sensor unit, and FIG. A graph showing the deformation state of the conductive rubber, Fig. 6 is a circuit diagram showing an example of the pressure sensor unit and the control circuit, and Fig. 7 also shows the correlation between the displacement amount of the presser and the resistance value of the conductive rubber. Graphs, Figures 8 and 9 are cross-sectional explanatory diagrams showing other embodiments of the pressure sensor unit, and Figure 1O is a graph showing the relationship between the resistance value of conductive rubber as a sensor element and the pressing force of the presser element. It is. A... Floppy disk drive device 1---- Floppy disk 2...
...Case 3---Pulse motor 6---Feed screw 7---Carriage 8 Magnetic heads 13, 13A, 13B--Pressure sensor unit 14...Substrate 15 with electrodes Pl, P2
--- Conductive rubber 17, 24, 25 --- Presser 22 --- Control circuit 27 --- Pressure spring S,, S, ---・・・・・・・・・・・・ Coil spring g -------------Minimum spacing To Figure 1 Figure 3 Figure 4 Figure 5 Figure 0 Presser/18 Motion □X''-8th Figure 9

Claims (4)

[Claims] (1) In a disk recording and reproducing device in which a disk having a desired plate shape is removably inserted into an insertion section and recorded and/or reproduced by means such as magnetic or laser, a recording and reproducing element is used. Changes in the position of the mounted carriage driven by a motor exert pressure on a pressure sensor unit, and an output signal from the pressure sensor unit controls the drive of the motor and regulates the stop position of the carriage. Disc position detection device for disc recording/playback equipment. (2) A disk position detection device in a disk recording and reproducing device according to claim 1, wherein the pressure sensor unit includes conductive rubber. (3) A disk position detecting device in a disk recording/reproducing device according to claim 1, wherein the pressure sensor unit is configured such that its output resistance value decreases in response to pressurizing force. (4) A disk position detecting device in a disk recording and reproducing device as set forth in claim 1, wherein the pressure sensor unit is configured such that an output resistance value increases with applied force.