JP3112867B2 - Optical information reader - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention reduces the movable range of focus correction control with respect to a warp of a disk, and makes it possible to make the configuration of an optical pickup small and simple. And an optical information reading device. 2. Description of the Related Art FIG. 1 is a side view of a part of a transfer device of a conventional optical information reading apparatus, and shows a case where there is no warp in the disk and a distance A between the disk 1 and the optical pickup 3 is constant. Is shown. In FIG. 1, a disk 1 is driven to rotate by a spindle motor 2.
An optical pickup 3 is arranged below the disk 1, and the optical pickup 3 is attached to a moving base 4 by a rotating shaft 5.
The disk 1 is held so as to be rotatable in the radial direction of the disk 1. The moving base 4 can be moved in the radial direction of the disc 1 along a guide rail 6 by a moving mechanism (not shown), and constitutes a feed mechanism. Further, an objective lens 7 is mounted on the optical pickup 3, and the light beam 8 condensed by the objective lens 7 irradiates the disk 1 to read information described on the disk 1. ing. FIG. 2 shows that the disk 1 warps upward,
FIG. 2 shows a case where the distance between the disk 1 and the optical pickup 3 is B. As shown in FIG. 2, when the disk 1 warps upward, the optical pickup 3 rotates around the rotation axis 5. The facing angle between the disk 1 and the optical pickup 3 is kept constant. However, according to the configuration shown in FIGS. 1 and 2, the slant component of the disk 1 follows the inclination component, but the vertical displacement component of the disk 1 follows. Does not follow, the only option is to rely on the tracking of the auto-focusing device in the optical pickup 3 such as the objective lens 7. As a result, the movable range of the auto-focusing device needs to have a tracking range enough to correspond to every disk 1. turn into. That is, in the example of FIG. 1, the distance A between the disk 1 and the optical pickup 3 is shown in FIG.
The distance becomes B, and in such a tilt correction mechanism, (B−A)
Is left uncorrected. SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and in an optical information reading apparatus, a light beam is focused on an information track on a disc-shaped information recording carrier. An optical pickup for detecting the reflected light from the information track to read the information; and an optical pickup for holding the optical pickup so as to be able to reciprocate in the radial direction of the disc-shaped information recording carrier, and at the middle of the disc-shaped information recording carrier in the radial direction. A holding means rotatably supported by the base at an appropriate position, and an angle of an optical axis of the optical pickup with respect to the surface of the disc-shaped information recording carrier by rotating the holding means with respect to the base. And a drive mechanism that enables the optical pickup to reciprocate in the radial direction of the disc-shaped information recording carrier. , A motor fixed to the holding means, a rotating member driven to rotate by the motor, and an engaging member fixed to the optical pickup and meshing with the rotating member. According to the optical information reading apparatus of the present invention, the angle of the optical axis of the optical pickup with respect to the surface of the disk-shaped information recording carrier is substantially constant with respect to the warped disk-shaped information recording carrier. Even if such control is performed, the change in the distance between the objective lens and the disc-shaped information recording carrier can be kept small, so that the operating range of the focus correction control can be reduced. Also,
Since the motor for reciprocating the optical pickup is fixed to the holding means, a driving mechanism for reciprocating the optical pickup even if the holding means holding the optical pickup rotates with respect to the base. It will be simple. Also, since the motor for reciprocating the optical pickup is fixed to the holding means, the position of the optical pickup in the radial direction of the disc-shaped information recording carrier is adjusted with respect to the surface of the disc-shaped information recording carrier. The angle adjustment of the optical axis of all the optical pickups and the adjustment of the distance between the objective lens and the disc-shaped information recording carrier can be accurately performed. An embodiment of an optical information reading apparatus according to the present invention will be described below with reference to the drawings. FIG. 3 is an exploded perspective view showing the configuration of the embodiment, FIG. 4 is a front view thereof, and FIG. 5 is a sectional view taken along line IV-IV in FIG. In FIGS. 3 to 5, reference numeral 10 denotes an optical pickup. On the front surface of the optical pickup 10, a pair of short cylindrical support portions 10a and 10b are integrally formed near the upper end edge. Support part 10
A guide rail 15 is inserted into each of a and 10b.
Optical pickup 10 in the radial direction of the disk
Is going to move. An L-shaped support plate 10C is formed at a lower portion near the front surface of the optical pickup 10, and a roller 13 is mounted on the support plate 10C by a roller mounting plate 14. ing. This roller 1
3. A rack mounting plate 12 is mounted on the optical pickup 10 together with the roller mounting plate 14, and the rack 11 is mounted on the rack mounting plate 12. The rack 11 is for moving the optical pickup 10 in the radial direction of the disk. As shown in FIG. 4, the rack 11 meshes with a pinion 19a provided in the radial transfer motor unit 19, and the rack 11 is actuated by the operation of the radial transfer motor unit 19. Move in the left-right direction (radial direction), whereby the guide rail 15
The optical pickup 10 can be moved in the radial direction along the axis. The radial transfer motor unit 19 is mounted on the mounting plate 17. The guide rail 15 is supported by the mounting plate 17. The mounting plate 17 is the rotating shaft 1
It is mounted on a base 16 so as to be rotatable around 8. The rotation shaft 18 is provided within a radial transfer range of the optical pickup 10. That is, the mounting plate 17
Has a role as a holding means for holding the guide rail 15 and swingably holding the guide rail 15 around the rotation shaft 18. The base 16 is fixed to a spindle motor (not shown). A tilt motor unit 20 is fixed near the left end of the base 16. An external thread is engraved on the shaft tip 22 of the tilt motor unit 20. A screw 17a is attached near the left end of the mounting plate 17.
Is screwed with the shaft tip 22. Reference numeral 21 denotes a tilt detecting unit for the disk 7 provided on the optical pickup 10. Next, the operation of the optical information reading apparatus of the present invention configured as described above will be described. When the tilt motor unit 20 is operated, the mounting plate 17
Rotate around 8. Accordingly, the guide rail 15, the optical pickup 10 and the like are tilted with respect to the disk. On the other hand, the disk inclination detecting section 21 can obtain information on the disk warpage. The disk warp information can also be obtained by the viewer adjusting the variable resistor by looking at the screen. When a correction signal is applied to the tilt motor unit 20 based on the warp information, the guide rail 15, the optical pickup 10 and the like rotate together with the mounting plate 17 about the rotation shaft 18, and the optical pickup 10 and the disc are rotated. Can be kept constant. The rack 11 is moved in the left-right direction via the pinion 19a by the operation of the radial transfer motor unit 19. Thus, the optical pickup 10 is transported along the guide rail 15 in the radial direction of the disk. FIGS. 6 and 7 are side views for clarifying the principle of the present invention. FIG. 6 shows a case where the disk is not warped, and FIG. 7 is a case where the disk is warped. Shows the case. FIGS. 6 and 7 correspond to the conventional FIGS. 1 and 2, respectively. In FIGS. 6 and 7, the disk 1, spindle motor 2, objective lens 7, and light beam 8 have the same reference numerals as those in FIGS. The optical pickup 10, the guide rail 15, and the rotating shaft 18 are denoted by the same reference numerals as those in FIGS. As shown in FIG. 6, when the disk 1 is not warped and the distance C between the disk 1 and the optical pickup 10 is maintained, as shown in FIG. As already mentioned, the tilt motor unit 2
When the guide rail 15 is rotated together with the mounting plate 17 about the rotation shaft 18 by operating the rotation of the optical pickup 10, the optical pickup 10 approaches the disk 1 while tilting. As a result, even after the inclination of the optical pickup 10 is corrected, the distance between the disk 1 and the optical pickup 10 is kept substantially equal to the distance D when there is no warp. Then, as shown in FIG. 7, the position of the rotating shaft 18 is selected at an appropriate intermediate position in the radial direction of the disk-shaped information recording medium, and by swinging, the angle and interval between the disk 1 and the optical pickup 10 are made substantially constant. Can be kept. As described above, the optical information reading apparatus according to the present invention can be used for a disk-shaped information recording carrier with a warp and an optical pickup for the optical pickup with respect to the surface of the disk-shaped information recording carrier. Even if the control is performed so that the angle of the axis becomes substantially constant, the change in the distance between the objective lens and the disc-shaped information recording carrier can be suppressed to a small value, so that the operating range of the focus correction control can be reduced. Also, since the motor for reciprocating the optical pickup is fixed to the holding means, even if the holding means holding the optical pickup rotates with respect to the base, the driving for reciprocating the optical pickup is performed. The mechanism becomes simple. Also, since the motor for reciprocating the optical pickup is fixed to the holding means, the position of the optical pickup in the radial direction of the disc-shaped information recording carrier is adjusted with respect to the surface of the disc-shaped information recording carrier. The angle adjustment of the optical axis of all the optical pickups and the adjustment of the distance between the objective lens and the disc-shaped information recording carrier can be accurately performed. [0018]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side view showing the principle of operation of a conventional transfer device of an optical information reading device when a disk-shaped information recording carrier is not warped. FIG. 2 is a side view showing the principle of operation of the transfer device of the conventional optical information reading device when the disk-shaped information recording carrier is warped. FIG. 3 is an exploded perspective view showing a configuration of one embodiment of a transfer device of the optical information reading device of the present invention. FIG. 4 is a front view of a transfer device of the optical information reading device. FIG. 5 is a sectional view taken along the line IV-IV in FIG. 4; FIG. 6 is a side view showing the principle of operation of the transfer device of the optical information reading apparatus of the present invention when the disk-shaped information recording carrier is not warped. FIG. 7 is a side view showing the operation principle of the transfer device of the optical information reading device of the present invention when the disk-shaped information recording carrier is warped. [Description of Signs] 1 ... Disk 2 ... Spindle motor 7 ... Objective lens 8 ... Light flux 10 ... Optical pickup 11 ... Rack 15G / Guide rail 16 ... Base 17 ... Mounting plate 18 ... Rotary shaft 19 ... Motor unit 20 for radial transfer ... Tilt motor unit 21 ... Tilt detector 22 ... Shaft tip

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-60-164936 (JP, A) JP-A-60-160034 (JP, A) Fully open sho 59-42571 (JP, U) Really open sho 58- 159644 (JP, U) (58) Field surveyed (Int. Cl. ⁷ , DB name) G11B ^7/ 08-7/10

Claims (1)

(57) [Claims] An optical pickup for converging a light beam on an information track on the disc-shaped information recording carrier and detecting reflected light from the information track to read information; and moving the optical pickup in a radial direction of the disc-shaped information recording carrier. Holding means rotatably supported by a base at an appropriate position in the radial direction of the disc-shaped information recording carrier so as to be reciprocally movable, and by rotating the holding means with respect to the base. Control means for controlling the angle of the optical axis of the optical pickup with respect to the surface of the disc-shaped information recording carrier to be substantially constant; and a drive mechanism for causing the optical pickup to reciprocate, The drive mechanism, a motor fixed to the holding means,
An optical information reading device comprising: a rotating member driven to rotate by the motor; and a meshing member fixed to the optical pickup and meshing with the rotating member.