JPH03245371A - Optical information recording and reproducing device - Google Patents

Abstract

PURPOSE:To make an optical information recording and reproducing device compact and thin, to enlarge thrust and to enable high-accuracy and high-speed access by driving the both sides of an optical head by a linear motor while rolling and engaging five fixed rollers fitted to the optical head and one pre- loading roller on two guide shafts with no contact passing through the optical head. CONSTITUTION:An optical head 4 is engaged with five fixed rollers 29 and 52 fitted to the optical head 4 and one pre-loading roller 30 on first and second guide shafts 27 and 28 arranged on a sub base, and the optical head is supported and guided. For the first and second guide shafts 27 and 28, a through-hole is bored on the optical head 4 and those guide shafts are fixed by a screw 37 while using a guide shaft presser 36 onto the sub base without any contact to the optical head 4. The optical head 4 can be moved in the radial (X axis) direction of an information recording disk by two tracking linear servo motors 5 arranged on the sub base. Thus, the device can be made compact and thin as a whole and the optical head can be stably positioned with high accuracy.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an optical information recording/reproducing device, and particularly to an optical information recording/reproducing device that is small, thin, highly rigid, and excellent in high-precision, high-speed positioning. Regarding.

[Conventional technology]

Conventionally, in optical information recording/reproducing devices such as optical disk file devices and CD-ROMs, various drive mechanisms and guide mechanisms have been devised for positioning optical heads at high speed and with high precision. In order to position the optical head at high speed and with high precision, it is necessary to have a highly rigid optical head structure and guide mechanism structure that prevent pitching and yawing of the optical head even in high frequency ranges. Not only that, but there is now a strong tendency to make devices lighter, thinner, and smaller, and there is a strong demand for particularly thin optical head drive devices.

Related devices of this type include, for example, Japanese Utility Model Application No. 58-109860 and Japanese Patent Application Laid-Open No. 62-46471. In Japanese Utility Model Application Publication No. 58-109860, the optical head is disposed below or driven by a near motor. In addition, a total of four rollers are attached to the optical head housing.
One grooved roller and one cylindrical roller above and below the first guide shaft, and above the second guide shaft.

By arranging one cylindrical roller below each, the optical head is driven and positioned.

3 In Japanese Patent Application Laid-Open No. 62-46471, left and right integrated drive coils formed to surround the optical head casing are provided in the optical head casing, and a guide shaft for linearly reciprocating the optical head and the driving coil is provided. are provided between the optical head housing and the center yoke of the magnetic circuit arranged on both sides of the optical head housing. Three rollers are placed on both sides of the optical head housing, each touching the guide shaft at a required angle to support the optical head and prevent displacement in the upward, downward, left, and right directions. It has a structure that allows for regulated linear reciprocating motion.

[Problem to be solved by the invention]

The above-mentioned conventional technology does not take into account the need to make the linear motor for driving the optical head with sufficient thrust and the guide mechanism for guiding the head smaller and thinner, and requires a larger linear motor because the head is heavy. In addition to this, it was not sufficient to improve the efficiency of linear motors. Another problem was that the arrangement of the linear motor and optical head guide mechanism was not appropriate for making the device smaller and thinner. Furthermore, since the center of gravity of the optical head and the center of thrust of the linear motor that drives the optical head are misaligned, pitching motion of the optical head tends to occur when the optical head moves, which hinders high-speed positioning of the optical head. There was a problem that there were cases where Furthermore, in order to ensure a wide bandwidth for the speed control system in order to perform high-speed access, it is necessary to increase the rigidity of the mechanical structure of the optical head by increasing the sub-resonant frequency of the mechanical structure. There was no mention of whether it would be possible to

An object of the present invention is to provide an optical information recording/reproducing device that is small, thin, has a large thrust, and is excellent in high-precision, high-speed access.

[Means for Solving the Problems] In order to achieve the above object, the present invention provides five guide shafts that pass through the optical head and are attached to the optical head on two guide shafts that are arranged without contacting the optical head. A fixed roller and one preload roller are rollingly engaged to enable stable and highly accurate positioning movement of the optical head, and both sides of the optical head are driven at high speed by linear motors. In order to increase the rigidity, the reinforcing partition wall of the optical spatula 1- was arranged in the axial direction of the drive coil fastening screw. A high-strength aluminum alloy is used for the drive coil bobbin, and the gap between the drive coils is reinforced with adhesive.

In addition, in order to increase the thrust as much as possible and make it thinner, magnetic circuits are installed above and below the drive coil to improve efficiency, and the width of the outer yoke that makes up the linear motor is wider than the width of the center yoke. The cross-sectional area of the outer yoke is made thinner by making the total thickness of the outer yoke smaller than the total thickness of the center yoke to the extent that it does not become smaller than the cross-sectional area of the outer yoke. Furthermore, by adjusting the width of the outer yoke in the two upper and lower magnetic circuits of the optical head, each thrust is changed, and the center of gravity of the optical head and the center of thrust are aligned, causing a pitching operation that interferes with high-speed positioning of the optical head. We aimed to reduce the

[Effect]

The reinforced bulkhead structure of the optical head, the high-strength aluminum alloy of the drive coil bobbin, and the adhesive reinforcement of the gap between the drive coils make it possible to increase the rigidity of the optical head, ensuring a wide speed control system band and 2-position control system band, resulting in high-speed operation. access becomes possible. In addition, magnetic circuits are provided above and below the drive coil, two sets of linear tracking servo motors are placed on the left and right sides of the optical head, and the outer yoke is widened, and
By making the device thinner, the entire device can be made smaller and thinner, and at the same time, a lightweight and efficient optical head access mechanism can be constructed. Also, the center of gravity of the optical head is above the magnetic circuit placed above and below the optical head.

When the position is above the midpoint of the distance between the two bottom thrust generating surfaces, the outer yoke width of the magnetic circuit placed below the optical head is made smaller than the outer yoke width of the upper magnetic circuit. When the center of gravity is below the midpoint of the distance between the upper and lower thrust generating surfaces of the optical head, the outer yoke width of the magnetic circuit placed above the optical head is smaller than the outer yoke width of the lower magnetic circuit. Also smaller and above the optical head.

Since the thrust generated by the lower two magnetic circuits is changed according to the position of the center of gravity of the optical head, the difference between the center of gravity of the optical head and the center of thrust can be reduced, and as a result, high-speed positioning of the optical head is possible. Disturbing pitching motion can be reduced.

Furthermore, since the optical head guide mechanism is configured with five fixed rollers and one preload roller, it is thin and can perform stable and highly accurate positioning of the optical head.

〔Example〕

Before going into a specific explanation of the optical head drive device, which is a characteristic part of the optical information recording and reproducing device according to the present invention, we would like to explain how this optical head drive device is positioned in the overall optical information recording device. Explain what you are doing.

FIG. I3 is a perspective view including a partial cross section of an optical information recording/reproducing apparatus which is an embodiment of the present invention. In FIG. 13, 1 is an information recording disk (an optical disk in this embodiment), and the material is 1, for example, polycarbonate (PC).
A transparent material such as resin) is used. The lower part of the information recording disk is covered with a transparent protective layer, on which pits representing digital information are carved, and a reflective surface is created by aluminum vapor deposition, and above the pit row is a transparent protective layer. is coated. The information recording disk may have, for example, tracks formed in a spiral or concentric pattern, or may or may not have grooves. The information recording disk 1 is rotationally driven by a disk drive motor 3 mounted on a sub-base 2. The disk drive motor 3 is driven by a disk motor driver 16.

4 is an optical head, which is an optical means for recording and reproducing.

The objective lens 7 has a built-in objective lens actuator 8 that focuses the objective lens on the recording surface of the information recording disk 1 and precisely drives the objective lens 7 in the disk vertical direction and radial direction. The semiconductor laser is always driven by the semiconductor laser driver 17 to obtain stable output. The optical head 4 is movable in the radial direction of the information recording disk 1 by a tracking linear servo motor 5 disposed on the sub-base 2, and performs a rough access operation to determine the approximate track position by moving the entire optical head □. In this embodiment, one tracking linear servo motor 5 is arranged on one side of the optical head 4, but one tracking linear servo motor 5 may be arranged on each side of the optical head 4. The tracking linear servo motor 5 is operated by a servo control circuit 10 based on commands from a system controller 1-roll microprocessor 9. It is driven via a tracking servo motor driver 11. At this time, the speed of the optical head is controlled by the output of the optical head speed sensor 6.

Similarly, when the objective lens actuator 8 is driven by the objective lens actuator focus coil driver 14 and the objective lens actuator track coil driver 15, the objective lens 7 focuses on the recording surface of the information recording disk 1. Tracked precisely in the tracking direction. The focusing operation and precision tracking operation of the objective lens are performed by amplifying the output of the photodetector built into the optical head 4 using a preamplifier 12 and a signal processing circuit 13, and calculating and creating a control signal. This is done by driving the .

FIG. 14 is a system diagram of the recording/reproducing optical system built into the optical head 4 of FIG. 13. In FIG. 14, the information recording disc 1 has pits 23 representing digital information.
is engraved. The light 26 emitted from the semiconductor laser 18 is
It passes through the diffraction grating 19, is bent at a right angle by a half mirror 20, passes through a collimating lens 21, is further bent at a right angle by a reflection prism 22, passes through an objective lens 7, and reaches the surface of the pit 23 of the information recording disk 1. Connect your focus. The light reflected from the pit surface passes through the objective lens 7 again.
, is bent at a right angle by a reflecting prism 22 , and collimated by a collimating lens 21 . Half mirror 20, plano-convex lens 2
4 and transfers the image onto a photodetector 25. The objective lens actuator 8 drives the objective lens 7 vertically to focus on the surface of the information recording disk 1, and also drives the objective lens 7 in the radial direction of the information recording disk 1 for precise tracking. do. The photodetector 25 is an element that converts the return light from the information recording disk 1 into an electrical signal, and detects a focusing error and a racking error based on the magnitude of the output of the electrical signal obtained here. death,
Performs focusing and tracking operations. The photodetector 25 also detects digital signals on the information recording disk surface at the same time.

Now, Figure ↓ is a plan view of an optical head drive device of an embodiment of the optical information recording/reproducing apparatus according to the present invention, Figure 2 is a front view of Figure 1 viewed from the X-axis direction, and Figure 3 is a FIG. 2 is a side view of FIG. 1 viewed from the y-axis direction.

In FIG. 1, the optical head 4 is a sub-base (not shown).
Two tracking linear servo motors 5 placed above
The optical head is movable in the radial direction (X-axis direction) of an information recording disk (not shown), and performs a rough access operation that determines the approximate track position by moving the entire optical head. The optical head 4 engages six rollers attached to the optical head 42- on a first guide shaft 27 and a second guide shaft 28 arranged on a sub-base (not shown) to support the optical head. ,
Guide. First guide shaft 27 and second guide shaft 2
8 has a through hole in the optical head 4, and a guide shaft holder 3 is mounted on the sub-base (not shown) without contacting the optical head 4.
6 and fix with screws 37. Four of the six rollers are fixed rollers 29, and the fixed rollers 29 are attached to the optical head 4. FIG. 10 is an enlarged view of the fixed roller 29. The fixed roller shown in FIG. 10 is of an integrated type with an inner ring and a shaft shown at 53, but it may also be one in which a straight shaft is press-fitted into a general rolling bearing.

The fixed roller 29 is attached by press-fitting or gluing the shaft 53 side to the optical head 4. One of the six rollers is the fifth fixed roller 52 and engages with the second guide shaft 28 at an angle. Preload roller 30 shown in FIG.
is disposed on the optical head 4 side at a position to clamp the second guide shaft 28, and cooperates with the fixed roller by spring pressure to clamp the second guide shaft with a predetermined pressure. FIG. 11 is a detailed diagram of the preload roller.

It is shown in FIG.

FIG. 11 is a diagram including a partial cross section of the preload roller mechanism section, and is a diagram viewed from the X-axis direction of FIG. 1.

The mounting state of each component constituting the preload roller mechanism is shown in more detail in FIG. I2. The preload roller mechanism is
Preload roller 30. Preload roller shaft 59° preload spring 54. A washer 55 with a trapezoidal cross section for fixing the preload spring
, and from the mounting screw 56. When the preload roller 30 is engaged with the second guide shaft (not shown), the preload spring 54
is in a slightly bent state. Then, the preload roller applies preload to the second guide shaft due to the spring reaction force. Preload spring 54
For example, laser beam welding is performed on the surface 58 of the preload roller shaft. Although screws may be used as a joining method, welding was used because using screws would increase the size of the device. Preload roller 3
0 is press-fitted or adhered to the preload roller shaft 59. The mounting portion of the preload spring 54 is made in a figure 9 shape following the shape of the preload spring mounting portion 60 of the optical head 4, and is mounted on the optical head 4 by a mounting screw 56 via a washer 55 having a trapezoidal cross section. Attach to 661. With this configuration, as shown in FIG. 11, it is possible to reduce the protrusion height dimension α of the preload mechanism section from the lower surface of the optical head housing, and as a result, the thickness t of the optical head 4 can be reduced, resulting in a thin design. equipment can be provided.

The rolling engagement between the guide shaft, fixed roller, and preload roller will be explained using FIG. 18. FIG. 8 is an enlarged view of the engaging portions of the guide shaft, fixed roller, and preload roller of the optical information recording/reproducing apparatus of the present invention shown in FIG. 2. The fixed roller 52 that rolls into engagement with the second guide shaft 28 has a second guide shaft center 64 and a contact point 66 between the guide shaft and the fixed roller.
The optical head 4 is arranged so that a line connecting the two lines forms an angle of approximately β (in this embodiment, W@45 degrees) with respect to the y-axis.

Further, the preload roller 30 is arranged on the optical head 4 so that the line connecting the second guide shaft center 64 and the contact point 67 of the guide shaft and the preload roller forms an angle of approximately −β with respect to the y-axis. There are four fixed rollers 29 that roll and engage with the first guide shaft 27. For the two fixed rollers 29 located above the X-y plane, the line connecting the first guide shaft center 63 and the contact point 65 between the guide shaft and the fixed roller 15- is approximately (πβ) with respect to the y-axis. are arranged on the optical head 4 so as to form an angle of .

The two fixed rollers 29 below the xy plane are arranged on the optical head 4 so that the angle is approximately (π+β).

Next, we will consider what angle is appropriate for the angle β. Second
FIG. 0 is an enlarged view of the fixed roller 29 that engages with the first guide shaft 27 in FIG. In Fig. 20, β is set to 45°, but Fig. 19 shows the case where β is set to 30”, and Fig. 21 shows the case where β is set to 60°.As shown in Fig. 19, β is small. If the angle β is smaller than 30°, the length α of the shaft 53 of the fixed roller 29 cannot be made sufficiently large. Firm fixation of the roller 29 to the optical head 4 cannot be expected.A must be at least as large as the diameter of the shaft 53.On the other hand, even if β is made small and h is made as thin as possible, the drive coil The thickness of
Since a dimension of about h shown in the figure is required, β is smaller than 30°, 4'7', and even if it is reduced to A6-, it cannot contribute to thinning. If β is increased as shown in FIG. 21, the thickness h of the device will increase, which goes against the desire to make the device thinner. On the other hand, if the thickness h of the device is given the dimension shown in FIG. High rigidity can be achieved. Considering the above points, it is desirable to set β to a value of approximately 45°,
It is practical to select the angle within the range of at least 30° to 30°.

The tracking linear servo motor 5 has a drive coil 31
．． Center yoke 32. Outer yoke 33 and magnet 3
Consists of 1. In order for the optical head access mechanism to generate a large thrust, it is better that the effective coil length of the tracking linear servo motor, that is, the length over which the drive coil is subjected to magnetic action, is long. The greater the ratio of the effective coil length to the total length of the drive coil, the more lightweight and large the thrust the tracking linear servo motor can be.

In consideration of the above points, and in order to further reduce the thickness of the optical head access mechanism, as shown in FIG. 2, two pairs of outer yokes 33. A magnet 34 is arranged, a center yoke 32 is passed through the drive coil without contact, and both ends of the outer yoke and center yoke are fixed to the sub-base 2 using bolts 38 to form a magnetic circuit. The surfaces that generate thrust are the upper and lower surfaces of the drive coil 39, and the ratio of the effective coil length to the total length of the drive coil is 0.6 in this embodiment, making it possible to create a lightweight, efficient tracking linear servo motor with large thrust. can be configured. Two sets of magnetic circuits are arranged on both sides of the optical head 4 to cope with large thrust.

In order to further reduce the thickness of the device without lowering the gap magnetic flux density or thrust of the tracking linear servo motor, the center yoke 32 shown with diagonal lines in Fig. 2 is used.
The cross-sectional shape of the yoke is selected so that its cross-sectional area is approximately equal to the sum of the cross-sectional areas of the two outer yokes placed above and below the center yoke. The width of the outer yoke 33 is made wider than the width a of the center yoke 32, and at the same time, the width is made thinner so that the entire device can be made thinner. The cross-sectional shape of the yoke was chosen so that the sum of the cross-sectional area of the center yoke and the cross-sectional area of the upper and lower two outer yokes is approximately equal, so even if the outer yoke is made thinner, the magnetic flux will not be saturated, and the necessary gap will be maintained. Magnetic flux density can be ensured.

FIG. 4 is a plan view of the optical head 4. A state in which the drive coil bobbin 31 and the drive coil bobbin mounting screw 35 are attached is shown by a two-dot chain line. The optical head 4 has reinforcing partition walls 42, 43.4-4. indicated by diagonal lines on the axis of the drive coil bobbin mounting screw 35. .

Place 45. Since the plate structure has higher rigidity in tension than in bending, by placing the reinforcing bulkheads mentioned above,
A structure that is strong against out-of-plane damage in the xy plane can be obtained.

FIG. 5 is a sectional view of FIG. 4 viewed from the X-axis direction, and represents a sectional view of the optical head structure.

FIG. 6 is a back view of the optical head 4. Similarly, here, the state in which the drive coil bobbin 31 and the drive coil bobbin mounting screw 35 are attached is shown by the two-dot chain line 19-. The back side of the optical head 4 is similar to the front side.

By arranging reinforcing partition walls 46, 47, and 48 indicated by diagonal lines on the axis of the drive coil bobbin mounting screw 35, the effect of increasing rigidity is significant.

FIG. 16 is an enlarged view of the reinforcing partition wall portion explained using FIG. 4 above. The reinforcing partition wall 47 is configured in the yz plane. The drive coil bobbin 31 is fastened to the optical head 4 using the drive coil bobbin mounting screw 35. The reinforcing wall 47 is
As shown in FIG. 16, the drive coil bobbin mounting screw 35
By arranging it on the extension of the axis 62, the effect of improving the rigidity against out-of-plane marks in the xy plane is large.

FIG. 17 is an enlarged view of another embodiment of the reinforcing partition wall.

In this example, high rigidity is achieved by arranging the reinforcing partition walls 62 and 63 from an extension of the axis 62 of the drive coil bobbin mounting screw 35 at a certain angle to the yz plane. By increasing the rigidity of the optical head by arranging reinforcing partition walls at such positions, it is possible to obtain a structure in which the sub-resonance point does not appear even in a high frequency range. As a result, a wide band can be secured for the 20-degree speed control system and the position control system, allowing high-speed access of the optical head.

7 is a front view of the drive coil 39 and drive coil bobbin 31 in FIG. 1, FIG. 8 is a plan view, and FIG. 9 is a side view. The drive coil bobbin 31 is fixed to the through hole 50 using four drive coil mounting screws (not shown). In order to increase the rigidity of the drive coil part, the drive coil bobbin 31 is
uses high strength aluminum alloy. However, since this material is a conductor and generates eddy currents during driving, resulting in a decrease in driving force, a slit is made in the drive coil bobbin 31 to open the eddy current path. A plastic material 49, which is a thin insulator, is inserted into the slit and bonded to ensure strength. The starting wire of the drive coil 39 is taken out from the hole 51 of the bobbin 31 and wound on the bobbin 31 in multiple layers.

In order to further increase the rigidity of the optical head 4, if a plastic plate (not shown) is inserted and bonded into the gap 40 shown in FIG. 1, the amount of deformation of the drive coil portion will be reduced and the effect of increasing the rigidity will be high.

In FIG. 2, guide shafts 27 and 28 that support and guide the optical head 4 may have circular cross-sections, as shown in the figure. However, in order to further increase the restraining force of the fixed roller 29° 52 and the preload roller 30 and increase the rigidity of the optical head support system, the cross-sectional shape of the guide shafts 27 and 28 may be made as shown in FIG. . FIG. 15 shows another embodiment of the optical information recording/reproducing apparatus shown in FIG. 2, in which fixed rollers 29, 52 protrude from the optical head 4, and a guide shaft 27 with a flat surface of a preload roller 30. Rolling contact with 28. In this way, the restraining force of the fixed roller and preload roller increases, the rigidity of the optical head support system increases, and a structure suitable for high-speed access can be obtained.

If there is a deviation between the center of gravity of the optical head and the center of thrust, a pitching motion may occur in the optical head, which may impede high-speed positioning.

FIG. 22 is an explanatory diagram of how the width of the outer yoke should be selected in order to suppress the rigid pitching motion of the optical head, and compared to FIG.

Preload rollers, guide shafts, etc. are omitted. FIG. 22 shows the case where the center of gravity G of the optical head 4 is above the midpoint of the distance between the thrust generating surfaces 71 and 72, that is, the vertical direction from the thrust generating surface 70 to the center of gravity G of the optical head 4. Q the distance
x, and the vertical distance from the thrust generating surface 71 to the center of gravity G of the optical head 4 is 2. This is an example for reducing the pitching operation when Ql<Qz. If the thrust generated at the thrust generating surface 70 is Ft, and the thrust generated at the thrust generating surface 71 is F2, then in order to suppress the rigid pitching motion around the center of gravity 0 of the optical head 4, Fl・Flood 1=F2
・Q2...F so that (1)
You can choose l, F2. Thrust generation surface 7 of drive coil 39
The gap magnetic flux densities on the 0 side and 71 side are respectively Btt
+Bg2, and the effective coil lengths at which the drive coils on the thrust generating surface 70 side and 71 side of the drive coil 39 are subjected to the magnetic field action are Ll and Ll, respectively, then the relationship between Fl and F2 is as follows.

23- Substituting equation (1) into the above equation gives It is possible to reduce pitching motion that hinders high-speed positioning of the head.

〔Effect of the invention〕

The present invention has a reinforced bulkhead structure for the optical head, a high-strength aluminum alloy for the drive coil bobbin, and adhesive reinforcement for the gap between the drive coils, making it possible to increase the rigidity of the optical head. This allows for high-speed access.

In addition, magnetic circuits are provided above and below the drive coil, two sets of linear tracking servo motors are placed on the left and right sides of the optical head, and the outer yoke is made wider and thinner, making the entire device more compact.

24- A thin, lightweight and efficient optical head access mechanism can be constructed. Also, the center of gravity of the optical head is above the magnetic circuit placed above and below the optical head.

When it is above the midpoint of the distance between the two lower thrust generating surfaces,
The outer yoke width of the magnetic circuit placed below the optical head should be smaller than the outer yoke width of the upper magnetic low circuit. When the magnetic circuit is located at the bottom, the outer yoke width of the magnetic circuit placed above the optical head is made smaller than the outer yoke width of the lower magnetic circuit, and the thrust generated by the two magnetic circuits above and below the optical head is transferred to the optical head. Since each is changed according to the position of the center of gravity, it is possible to reduce the deviation between the center of gravity of the optical head and the center of thrust, and as a result,
Pitching that hinders high-speed positioning of the optical head can be reduced. Furthermore, since the optical head guide mechanism is configured with five fixed rollers and one preload roller, it is thin and can perform stable and highly accurate positioning of the optical head.

[Brief explanation of drawings]

FIG. 1 is a plan view of an optical head drive device in an optical information recording/reproducing apparatus according to an embodiment of the present invention, FIG. 2 is a front view of FIG. 1 viewed from the X direction, and FIG. 3 is a view similar to FIG. 4 is a plan view of the optical head housing portion in FIG. 1, FIG. 5 is a sectional view of FIG. 4, FIG. 6 is a back view of FIG. 4, and FIG. 7 is a side view seen from the y direction. is a front view of the drive coil and drive coil bobbin in FIG. 1, FIG. 8 is a plan view of FIG. 7, FIG. 9 is a side view of FIG. 7, and FIG. 10 is an enlarged view of the fixed roller in FIG. 1. 11 is a partial sectional view of the preload roller mechanism shown in FIG. 1, and FIG. 12 is a perspective view of the components of the preload roller mechanism shown in FIG. 11. FIG. 13 is a perspective view including a partial cross section of an optical information recording/reproducing device which is an embodiment of the present invention, and FIG. 14 is a system of a recording/reproducing optical system built into the optical head of FIG. 13. 15 is a sectional view of another embodiment of the guide shaft, FIG. 16 is an enlarged view of the reinforcing partition shown in FIG. 4, and FIG. 17 is an enlarged view of another embodiment of the reinforcing partition, Fig. 18 is an enlarged view of the engaging part of the guide shaft, fixed roller, and preload roller; Figs. 19 to 21 are enlarged views of the fixed roller and the first guide shaft engaging part; Fig. 22 is the center of gravity of the optical head. FIG. 6 is an explanatory diagram showing the relationship between the position and the outer yoke width of the magnetic circuit. l...information recording disk, 2...sub-base, 3.
...Disk drive motor, 4...Optical head, 5...
- Tracking linear servo motor, 6... Optical head speed sensor, 7... Objective lens, 8... Objective lens actuator, 9... System control microprocessor, 10... Servo control circuit, 1
1...Tracking linear servo motor driver, 1
2... Preamplifier, 13... Signal processing circuit, 14.
・Objective lens naft unita focus coil driver, 15... Objective lens actuator track coil driver, 16... Disk motor, 17... Semiconductor laser driver, 18... Semiconductor laser, 19...
・Diffraction grating, 20...half mirror 121...co=
66 Straw 7 Fuzuzu Tomizu No. 1ρ Figure 6 /d Figure JP-A-3 245371 (12) Arithmetic/7 Figure abuse 9 Ward 7CU Wa

Claims (1)

[Scope of Claims] 1. An optical device equipped with a disk for recording information, a rotary drive device for the disk, and an optical means for recording or reading information in a recording area on the surface of the disk. In an optical information recording/reproducing device including a head, a course actuator for moving and positioning the optical head in a radial direction of the disk, and a guide mechanism, the coarse actuator is disposed on one or both sides of the optical head. , the coarse actuator includes a drive coil attached to the optical head, a center yoke disposed in a non-contact manner in the drive coil, and a center yoke arranged in parallel with a surface parallel to the surface of the disk among the surfaces of the center yoke. The guide mechanism, which is composed of one or two pairs of magnets and an outer yoke arranged without contacting the outer surface of the drive coil and supports and guides the optical head, has a first guide shaft disposed in the moving direction of the optical head. a second guide shaft parallel to the first guide shaft and spaced apart from the first guide shaft; five fixed rollers and one preload roller; One fixed roller and one preload roller installed on the optical head roll and engage with each other, and the plane including the center lines of the first guide shaft and the second guide shaft is defined as an xy plane, and the plane extends in the optical head feeding direction. If we take the x-axis, the y-axis perpendicularly to the x-axis, and the z-axis vertically, the fixed roller that rolls and engages the second guide shaft is centered between the center of the second guide shaft and the second guide shaft and the z-axis. The optical head is arranged so that a line connecting the contact point of the fixed roller forms an angle of approximately β with the y-axis, and the angle β is 30° to 30°.
60°, and the preload roller is arranged such that a line connecting the center of the second guide shaft and a contact point of the second guide shaft and the preload roller forms an angle of approximately -β with the y-axis. are arranged on the optical head, and four fixed rollers installed on the optical head roll and engage with the first guide shaft,
The two fixed rollers located above the x-y plane are such that a line connecting the center of the first guide shaft and the contact point of the first guide shaft and the fixed roller is approximately () with respect to the y-axis. π−β)
The two fixed rollers below the x-y plane are arranged on the optical head 4 so that the angle is approximately (π+β), and the preload is An optical information recording/reproducing device characterized in that the optical head is provided with a preload mechanism using a preload spring for pressing a roller against the second guide shaft with a predetermined pressure and clamping the optical head.