Information reproduction apparatus

Abstract: This invention relates to an information reproduction apparatus, and more particularly to an actuator locking mechanism for locking the linear actuator to the base portion of the apparatus in order to prevent the damage due to mechanical shock at non-operation time. Linking with load/unload mechanism, the locking mechanism engages with the actuator at a predetermined position. The locking mechanism has magnetic means for enhancing the engagement of the actuator and the locking mechanism.

Description: This invention relates to an information reproduction apparatus such as an optical disk storage apparatus, and more particularly to a locking mechanism for locking an actuator within the information reproduction apparatus in order to protect the actuator from being damaged due to vibration or mechanical shock during non-operation or transport. A linear actuator of an optical disk storage apparatus has precision optical instruments or electronic circuits, and can move at a high speed in the radial direction of a disk. Therefore, if the actuator moves freely, it is apt to receive a mechanical shock at the time of transport. To avoid this, a mechanism has been proposed for locking the actuator when a recording medium is removed from the information reproduction apparatus. Such a locking mechanism having the features defined in the preamble of appended claim 1 is disclosed in US-A- 4574372. However, locking means for locking the actuator must usually be accommodated in a narrow space and thus the allowed range within which said locking means can move is very restricted. In addition, tolerance in each component of the locking means brings about looseness in said locking means. For the above reason, the conventional locking means cannot ensure that the actuator is locked. According to the present invention as defined in appended claim 1, there is provided an information reproduction apparatus having means supported by an actuator for reading information from a recording medium, said actuator being movable to access the surface of the recording medium, loading and unloading means for transferring the recording medium between an initial insertion position and a reproduction position, and locking means linked with said loading and unloading means for locking said actuator, said locking means having engagement means which engage with said actuator in order to restrict the movement of the actuator, linking means for linking said engagement means with said loading and unloading means, and magnetic means for enhancing the engagement of said engagement means with said actuator. In the Drawings: FIG. 1A and FIG. 1B are enlarged front views showing operations different from each other with respect to the principal part of an embodiment of an information reproduction apparatus constructed in accordance with the present invention. FIG. 2 is an exploded perspective view showing the whole construction of said embodiment. FIG. 3A to FIG. 3C are side views showing operations different from one another with respect to loading and unloading means of said embodiment. FIG. 4 is an enlarged perspective view showing a drive source and motive power transmitting means of said embodiment. FIG. 5 is an exploded perspective view showing an actuator and locking means, of said embodiment. FIG. 6 is a exploded perspective side view showing an enlarged carriage assembly and a motor part of an actuator of said embodiment. FIG. 7A and FIG. 7B are enlarged and exploded perspective views showing operations different from each other with respect to a slider bracket and locking means of said embodiment. FIG. 8A to FIG. 8C are enlarged side views showing operations from one another with respect to engagement pins and engagement of said embodiment. FIG. 2 shows an embodiment of an information reproduction apparatus constructed in accordance with the present invention. In the figure, loading and unloading means 100 comprises a pair of guide plates 13, a slider bracket 15, and an upper bracket 17 fixed to a base 11. The base 11 is a nearly square tray, with slightly raised edges, whose longitudinal axis is in the direction of insertion of, for example, a recording medium 200 (such as disk cartridge, etc.) and a spindle motor 21 is mounted on the bottom surface of the base 11. As shown later, a position in the state where the recording medium 200 has been mounted on the spindle motor 21 indicates the reproduction position of the recording medium 200. On each of the outsides of both side walls of the base 11, the guide plate 13 is fixed by screws 23. Both guide plates 13 are parallel to each other and are fixed perpendicular to the bottom surface of the base 11. In each guide plate 13, two reversed L-shaped slots 25 are arranged horizontally at a predetermined distance. Moreover, at a rear end of the guide plate 13, a latch releasing block 27 is fixed by screws 29. Between both guide plates 13, the slider bracket 15 is arranged. The slider bracket 15 is supported so that it can slide on the upper surface of the base 11. In the bottom surface 34 of the slider bracket 15, multiple long and slender holes 31 are made and, on the other hand, from the upper surface of the base 11, multiple guide bosses 33 which penetrate the long and slender holes 31, protrude. The holes 31 are elongated in the direction of insertion of the recording medium 200 and the slider bracket 15 is guided by the guide bosses 33 so that it can slide in said direction of insertion. The slider bracket 15 includes raised sections 35, which are parallel to the guide plates 13 and arranged adjacently along the insides of both guide plates 13, at its two ends. In each of the raised sections 35, multiple oblique slots 37 are made. The oblique slots 37 are inclined slightly upwards from the front (an insert slot 260) of the information reproduction apparatus to the rear in the direction of insertion. To the bottom surface 34 of the slider bracket 15, a rack body 39 is fixed by screws 39B at its predetermined positions and on the rear side of the rack body 39, as shown in the figure, a rack gear 39A is formed. The upper bracket 17 is formed as a nearly square plate and its two sides are folded downward with the surfaces outside in a U shape. The U-shaped sections 41 of said both sides face each other and hold the recording medium 200 on the bottom surface of the upper bracket 17. From the outside surface of the U-shaped section 41, pins 43 protrude and penetrate both the oblique slots 37 and the reversed L-shaped slots 25. Therefore, if the slider bracket 15 slides forward and backward in the direction of insertion of the recording medium 200, the upper bracket 17 moves accordingly in a reversed L-path along the reversed L-shaped slots 25. The upper bracket 17 is provided with a shutter driving arm 45, which is attached to a flat section 42 of the upper bracket 17 so that it can turn. At the turning end of the shutter driving arm 45, a shutter driving pin 47 protrudes downward and moves in an arc-shaped slot 49 in a state where it protrudes downward from the arc-shaped slot 49 in the flat section 42 as the shutter driving arm 45 turns. The shutter driving arm 45 is attached so that its turning end pushes and removes the recording medium 200 by means of a spring 51. If the recording medium 200 is inserted into the upper bracket 17 (U-shaped sections 41), the shutter driving pin 47 contacts the tip (rightmost part in the figure) of a shutter 63 of the recording medium 200 at a predetermined depth of insertion. As the depth of insertion of the recording medium 200 into the slider bracket 17 becomes greater, the shutter 63 slides left in the figure by means of the shutter driving pin 47 and if the recording medium 200 is inserted into the innermost part, the shutter 63 is fully opened. Each of the U-shaped sections 41 of the upper bracket 17 is provided with a latch spring 53 fixed by screws 55 at predetermined positions of its farthest end and the latch spring 53 has a latch projection 57 formed at its end. The latch spring 53 and the latch projection 57 constructs a latch assembly 59 for latching the recording medium 200. The recording medium 200 has notches 61 formed on both sides toward its rightmost end, and if the recording medium 200 is inserted at a predetermined depth into the upper bracket 17, each latch projection 57 enters each notch 61 and thus the recording medium 200 is latched (held), with the shutter 63 opened, by the upper bracket 17. Moreover, the flat section 42 of the upper bracket 17 has multiple attached leaf springs 71, which push the recording medium 200 held by the U-shaped sections 41 downward so that the recording medium 200 does not rattle within the upper bracket 17. In a front panel 250, the insert slot 260 from which the recording medium 200 is inserted into the information reproduction apparatus, that is, into the upper bracket 17, is made. The front panel 250 is provided with an eject button 270. If the eject button 270 is operated, a drive source 300 described later drives the slider bracket 15 to eject the recording medium 200. In the following, the operations of the loading and unloading means 100 are described by reference to FIG. 3 in addition to FIG. 2. As shown in FIG. 3A, at an initial state (where the recording medium 200 is not inserted in the information reproduction apparatus), the upper bracket 17 of the loading and unloading means 100 is arranged most closely to the insert slot 260 of the front panel 250. In this case, each of the pins 43 of the upper bracket 17 is located at the leftmost end (closest to the insert slot 260) of the horizontal part of each reversed L-shaped slot 25 and the slider bracket 15 is arranged most closely to the insert slot 260 in all strokes. If the recording medium 200 is inserted into the upper bracket 17 at the position closest to the insert slot 260, a position at which the recording medium 200 is present is referred to as an insertion position. If the upper bracket 17 is present at the above position, the tip of each latch spring 53 gets on each latch releasing block 27, and bends and leaves the recording medium 200. Therefore, the latch projections 57 at the tips of the latch springs 53 do not enter the notches 61 of the recording medium 200 and thus the recording medium 200 is placed in a state where it is released from the latch assemblies 59. Therefore, if the upper bracket 17 remains not moved from the above position as in a case where the electric power source is turned off and the drive source 300 is at the non-operation time, the recording medium 200 is ejected from the insert slot 260 by means of a spring 51 by removing a hand from the recording medium 200 even though the recording medium 200 is inserted into the innermost part of the upper bracket 17. If the recording medium 200 is deeply inserted into the upper bracket 17 in a state shown in FIG. 3A, the tip of the recording medium 200 operates a micro switch not shown, thereby the drive source 300 described later starts, its driving force is transmitted, through transmitting means described later, to the slider bracket 15, and then the slider bracket 15 starts to move to the inner part (move left in the figure). In the state (at the recording medium latch position) shown in FIG. 3B, the slider bracket 15 slides toward the inner part by a predetermined distance and the upper bracket 17 remains unchanged at the same horizontal position as in FIG. 3A and moves toward the inner part by a predetermined distance. As a result, the tip of each latch spring 53 removes from each latch releasing block 27, the latch projections 57 at the tips of the latch springs 53 enter the notches 61 of the recording medium 200, and thus the recording medium 200 is latched, by means of the latch assemblies 59, in the upper bracket 17. The shutter 63 of the recording medium 200 is released by the shutter driving pin 47 according to the insertion of the recording medium 200 and if a hand is removed from the recording medium 200 before the latch assemblies 59 latch the recording medium 200, the recording medium 200 is returned toward the insert slot 260 by means of the spring 51. On the other hand, once the latch assemblies 59 latch the recording medium 200, the shutter 63 of the recording medium 200 will remain fully opened and be held by the upper bracket 17. FIG. 3C shows the state where the recording medium 200 has reached the reproduction position. If the slider bracket 15 slides toward the inner part from the recording medium latch position shown in FIG. 3B and reaches the innermost position in all strokes, the pins 43 of the upper bracket 17 reach the bottom ends of the vertical sections of the reversed L-shaped slots 25 and a disk (not shown) within the recording medium 200 is mounted accordingly, on the spindle motor 21 so that information can be read from or written to the disk. FIG. 4 shows the drive source 300 and the transmitting means 400 which drive the loading and unloading means 100. In the figure, the drive source 300 such as a motor, etc. is fixed to a base 410 for the transmitting means, a worm gear 310 is attached to an output shaft of the drive source 300, and the worm gear 310 is engaged with a large gear wheel 320A of a first gear 320. A small gear wheel 320B of the first gear 320 engages with a large gear wheel 330A of a second gear 330, a small gear wheel 330B of the second gear 330 engages with a large gear wheel 340A of a third gear 340, and a small gear wheel 340B of the third gear 340 engages with the rack gear 39A of the rack body 39 fixed to the slider bracket 15. From the base 410 for the transmitting means, relational shafts 420, 430, and 440 of the first, the second, and the third gears 320, 330, and 340 protrude, respectively. The worm gear 310, the first gear 320, the second gear 330, the third gear 340, and the rack gear 39A are arranged in a sequence of gears 455 for transmitting the driving force of the drive source 300. The relational shafts 420, 430, and 440 of the first, the second, and the third gears have washers 420A, 430A, and 440A, respectively, at their ends. FIG. 5 shows an actuator 700 and locking means 800 of the embodiment. The actuator 700 is referred to as a linear actuator on which a rotary actuator 702 is mounted. The rotary actuator 702 supports an objective lens 704 so that it can move freely. The actuator 700 includes a carriage assembly 708 with a plurality of bearings 710. To the base 11, a guide rail 712 which supports the bearings 710 is fixed. The actuator 700 is supported by the rail 712 so that it can move freely in the radial direction of the disk of the recording medium 200. The carriage assembly 708 includes a linear-type voice coil motor 714 which drives the actuator 700 in said radial direction. The base 11 is provided with a crash stopper 750 which contacts the actuator 700 to restrict the range of its movement. FIG. 6 is an enlarged perspective view of the carriage assembly 708 and the voice coil motor 714. The voice coil motor 714 comprises a coil 716, a magnet 760, a yoke 718, a counter yoke 720, and a bracket 722. The coil 716 is fixed to the carriage assembly 708. The counter yoke 720 is loosely inserted into the coil 716. The counter yoke 720 remains connected to the yoke 718, and is fixed, by a bracket 722, to the base 11. In the figure, the leakage flux from a magnet 760 is shown. FIG. 7A and FIG. 7B are enlarged perspective views of locking means 800 comprising engagement means 802 which engage with the actuator 700 to restrict the movement of the actuator 700, linking means 804 for linking the engagement means 802 with the loading and unloading means 100, and magnetic means 806 for enhancing the engagement of the engagement means 802 and the actuator 700. The engagement means 802 comprises a plate-shaped lifting member 812 a longitudinal axis of which is in the direction of the movement of the actuator 700, with its part wavily crooked, an arm member 814 which contacts both ends of the lifting member 812, a base member 816, and engagement pins 822 (refer to FIG. 8), being a rectangle-shaped frame. The tips of the arm members 814 on the side of the base member are supported, through shafts 818, to fixed plates 820 fastened to the base 11 so that it can be turned. Thus the lifting member 812 is supported so that it can turn freely up and down in the figure about the shafts 818. The engagement pins 822 protrude from the bottom surface of the carriage assembly 708 (Refer to FIG. 8). On the other hand, the lifting member 812 has an engagement hole 824 made in the valley of its wavy part. When the lifting member 802 is raised and the engagement pins 822 engage with the engagement hole 824, the actuator 700 is fixed to the base 11. In the lifting member 812, in addition to the engagement hole 824 a long and slender hole 826 elongated in the direction of the movement of the actuator 700 is made and the engagement pins 822 are loosely inserted and can move freely in the long and slender hole 826. Except that the engagement pins 822 engage with the engagement hole 824, the lifting member 812 is not an obstacle to the movement of the actuator 700. The linking means 804 comprises a cam plate 832 fixed, as a single piece, to the base member 816, a cam hole 834 made in the cam plate 832, and a cam body 836 engaged with the cam hole 834. The cam body 836 protrudes downward from the back surface of the slider bracket 15 of the loading and unloading means 100. The cam hole 834 inclines in the direction of the movement of the slider bracket 15, that is, in the direction of the movement of the cam body 836 and, as shown in FIG. 7A, if the slider bracket 15 is at the reproduction position of the disk, the cam body 836 is present in the innermost part (the leftmost end in the figure) of the cam hole 834 and thus the lifting member 812 is placed at the lowered position. On the other hand, as shown in FIG. 7B, if the slider bracket 15 is at the disk ejection (insertion) position, the cam body 836 is in the outermost part (the rightmost end in the figure) of the cam hole 834 and thus the lifting member 812 is placed at the raised position. That is, if the slider bracket 15 moves forward and backward, the actuator 700 is locked by the engagement means 802 or removed from the engagement means 802. Magnetic means 806 comprise a magnetic substance 840 and the magnet 760 (Refer to FIG. 6) and the magnetic substance 840, which is attached to the base member 816. The magnetic substance 840 is arranged downward perpendicularly to the magnet 760, receives the upward force of the leakage flux from the magnet 760 and the lifting member 812 always receives the upward force accordingly so that the lifting member 812 does not rattle. In the following, the operations of the embodiment are described by reference to FIG. 1A and FIG. 1B as well as FIG. 8A to FIG. 8C. If the eject button 270 is pushed in a state where the recording medium 200 is inserted in the apparatus, the carriage assembly 708 moves toward the innermost part of said apparatus until it contacts one crash stopper 750 (rightmost stopper shown in FIG. 5) and then stops. If the carriage assembly 708 contacts the crash stopper 750 and stops, then the drive source 300 starts and the slider bracket 15 moves from the state shown in FIG. 7A to the state shown in FIG. 7B to eject the recording medium 200 from the apparatus. In this case, the locking means 800 operates through linking with the slider bracket 15. If the slider bracket 15 is at the disk reproduction position (shown in FIG. 7A), the engagement means 802 of the locking means 800 is lowered and the locking means 800 unlocks the actuator 700. On the other hand, if the slider bracket 15 shifts to the disk ejection position (shown in FIG. 7B), then the engagement means 802 is raised to lock the actuator 700. FIG. 1A and FIG. 1B show that the raising and the lowering of the lifting member 812 of the engagement means 802 locks and unlocks the carriage assembly 708, respectively. The raising and lowering of the lifting member 812 causes a rattle based on tolerance in parts. However, since the magnetic substance 840 on the base member 816 of the engagement means 802 is almost under the magnet 760 and the lifting member 812 always receives the upward force, a rattle is removed, the engagement pin 822 just engages with the engagement hole 824 and thus the carriage assembly 708 is just locked. FIG. 8A to FIG. 8C show the state where the actuator 700 (carriage assembly 708) stops and then the lifting member 812 is raised to lock the carriage assembly 708, seen from an angle different from FIG. 1A and FIG. 1B. As shown in the figures, since the engagement hole 824 of the engagement means 802 is made in the valley of the wavily crooked portion 812A in the lifting member 812, the engagement pin 822 just engages with the engagement hole 824 even if the engagement pin 822 is not just above the engagement hole 824. According to the embodiment, even if the range (stroke) within which the lifting member 812 moves is reduced due to accommodation in narrow space and the lifting member 812 rattles due to tolerance in parts, the actuator 700 can be just locked since the magnetic means 806 for enhancing the engagement of the actuator 700 and the engagement means 800 are provided. The magnetic means 806 are constructed so that the leakage flux from the magnet 760 of the voice coil motor 714 is operated on the magnetic substance 840 of the lifting material 812. Therefore, it is unnecessary to provide a certain magnet for the magnetic means 806 and thus the apparatus simple in construction can be put in practice. The locking means 800 linking with the slider bracket 15, the locking means 800 can be easily arranged under the slider bracket 15. Under the slider bracket 15, there is a certain degree original space. If the locking means 800 is accommodated in the space, the small-sized apparatus can be put in practice. Further, if an attempt to link the locking means 800 with the upper bracket 17 is made, the linking means will become complex in construction, and it is particularly difficult to reduce the width of the apparatus. However, the embodiment facilitates putting a small-sized apparatus into practice even in the above case. The magnetic means is not restricted to the use of the leakage flux of the voice coil motor. However, if the leakage flux from the voice coil motor is used, the effect described above can be obtained. Further, the construction of the locking means are not restricted to the case of said embodiment. It will be appreciated that pins may protrude from the locking means and the pins may engage with holes made in the actuator. The actuator can be locked through a concave or a convex sections. However, it will be appreciated that the actuator may be locked due to frictional force of compressing force, etc.

Claims: An information reproduction apparatus having means supported by an actuator (700) for reading information from a recording medium (200), said actuator (700) being movable to access the surface of the recording medium, loading and unloading means (100) for transferring the recording medium between an initial insertion position and a reproduction position, and locking means (800) linked with said loading and unloading means for locking said actuator, said locking means having engagement means (802) which engage with said actuator in order to restrict the movement of the actuator, and linking means (804) for linking said engagement means with said loading and unloading means, characterised by magnetic (806) means for enhancing the engagement of said engagement means (802) with said actuator (700). An information reproduction apparatus according to claim 1, wherein said magnetic means use the leakage flux generated in a driving motor of the actuator and magnetic material provided to said engagement means. An information reproduction apparatus according to claims 1 and 2, wherein said loading and unloading means have an upper bracket which holds a recording medium and moves up and down and a slider bracket which moves in the direction of insertion/ejection of the recording medium in order to move the upper bracket, said engagement means being linked with said slider bracket. An information reproduction apparatus according to claim 3, wherein said engagement means have a lifting member which moves up and down to lock or unlock an actuator and said linking means have a cam mechanism for converting the movement of a slider bracket in the direction of insertion or ejection into the vertical movement of said lifting member. An information reproduction apparatus according to claim 1, wherein the recording medium is an optical disk or a cartridge containing the optical disk and the actuator is a linear actuator which can move in the radial direction of an optical disk, having a motor for driving said actuator, said loading and unloading means having an upper bracket which holds the optical disk or the cartridge containing the optical disk and moves up and down and a slider bracket which moves in the direction of insertion or ejection of the optical disk in order to move the upper bracket, said locking means being linked with said slider bracket and said linking means for linking said engagement means being linked with said slider bracket, whereby said magnetic means enhance the engagement of said engagement means with said actuator by using the leakage flux from said motor.

Inventors: NANKE KOICHIRO, NANKE, KOICHIRO
Applicants: IBM, INTERNATIONAL BUSINESS MACHINES CORPORATION
Application year: 1991
Main classification: G11B17
IPC codes: G11B21, G11B33, G11B17