Tray moving mechanism for disk drive
The present invention relates to a spring driven tray moving mechanism for a disk drive, e.g. an optical disk drive, and to a disk drive using such tray moving mechanism.
Current disk drives with a tray need an electric motor for moving the tray out of the player and for moving the tray back into the player. In order to save the cost for this electric motor it has been proposed to use a compression or tension spring to drive the tray.
For example, US 5,699,338 discloses a disk drive having a tray which is driven by a tension spring. For moving the tray out of the player, the user pushes a door open knob and thus releases the spring. The spring then pulls the tray through an opening of the player. In order to slow down the movement of the tray, the tray is provided with a tooth rack, which interacts with a damping mechanism. For moving the tray into the player the user pushes the tray through the opening completely into the player and thus loads the tension spring.
The solution according to the prior art has the disadvantage that the movement caused by the loaded spring is not constant. It starts quickly after release of the spring, reaches a high speed and then slows down at a nearly constant rate. Such an abrupt or uneven movement is not pleasant for the user and might even cause damages For example, the disk might move due to the high acceleration and collide with other elements.
It is, therefore, an object of the invention to propose a spring driven tray moving mechanism which achieves a similar speed characteristic as a tray moving mechanism employing an electric motor.
According to the invention, this object is achieved by a method for moving a tray of a disk drive with a spring, including the steps of:
- - moving a level adaptor with the spring for lowering a disk module without moving the tray during an initial phase,
- moving the tray into a position where the tray interacts with the spring by further moving the level adaptor with the spring, the movement of the tray being caused by an interaction with the level adaptor, and - moving the tray with the spring.
According to a further aspect of the invention, this object is also achieved by a mechanism for moving a tray of a disk drive, including: - a spring for moving the tray, and
- a level adaptor for lowering a disk module during an initial phase, and for bringing the tray into a position where the tray interacts with the spring, the level adaptor being moved by the spring.
The movement of the level adaptor is used for performing a variety of actions. During an initial movement phase the level adaptor is moved without causing any movement of the tray. However, during this initial movement phase a disk module is lowered by the level adaptor. After the initial movement phase the level adaptor moves the tray outward into a position where it can interact with the spring. The tray is then directly moved smoothly outward by the spring.
Favorably the interaction of the tray with the level adaptor is realized by a pin of the level adaptor cooperating with a recess of the tray. By suitably designing the recess the desired speed profile is achieved. Preferably the recess has a first part running parallel to the movement direction of the level adaptor, and a second part which is inclined relative to both the movement direction of the level adaptor and the
movement direction of the tray. During the initial movement phase the pin moves within the first part of the recess without causing any movement of the tray. During this phase a further pin located at the front of a disk module interacts with a further recess of the level adaptor for lowering the disk module. When the pin arrives at the second, inclined part of the recess, the tray is moved outward by the pin due to the interaction with the second part of the recess.
Advantageously the spring is a torsion spring. Compared to the solution known from the prior art this type of spring has the advantage that less space is required for mounting the spring. Preferably, when using a torsion spring the level adaptor has a gear rack portion, the tray has a gear rack, and the movement of the level adaptor and the tray is driven by a gear powered by the spring. Since a torsion spring is most suitable for powering a rotational movement gear racks are necessary for transforming this rotational movement into linear movements of the tray and the level adaptor.
Favorably a further spring is provided for reducing the tolerance between the gear rack portion of the level adaptor and the gear. In this way a smoother and more reproducible initial movement of the level adaptor is achieved.
Advantageously, a lever arm is provided for locking the level adaptor in its rest position. As the spring is strained when the tray is retracted in the disk drive, this measure prevents an unintentional extraction of the tray.
According to a further refinement of the invention, a speed regulating means is provided for ensuring an essentially constant movement speed. Examples for such a speed regulating means are known from mechanical watches, e.g. the balance of a watch or a clock.
For a better understanding the invention shall now be explained in more detail in the following description with reference to the figures. It is understood that the invention is not limited to this exemplary embodiment and that specified features can also expediently be combined and/or modified without departing from the scope of the present invention. In the figures:
Fig. 1 shows an optical disk drive having a spring driven tray moving mechanism according to the invention,
Fig. 2 depicts an operating sequence of the tray moving mechanism,
Fig. 3 shows further views of the operating sequence of the tray moving mechanism, and
Fig. 4 illustrates the different forces acting in the tray moving mechanism.
Though in the following the invention is described for an optical disk drive, it is likewise applicable to other types of drives having a tray, e.g. drives for magnetic disks or tapes.
Fig. 1 shows an exploded view of an optical disk drive having a spring driven tray moving mechanism according to the invention. A disk module 9 for reading from and/or writing to a disk (not shown) is mounted on a support bracket 8. A tray 13 is provided for receiving a disk for playback or recording. On one side the tray has a gear rack (not shown) . Attached to the front of the tray 13 is a faceplate 14 (door) for sealing an opening for the tray in a disk player or recorder when the tray 14 is in a playback or recording position. In order to secure a disk, which is placed on a turntable portion of the disk module 9, during playback or recording, the support bracket is further provided with a magnet holder 2. The tray moving mechanism mainly includes a main gear 3 driven by a torsion spring 6,
which is mounted with a mounting screw 1 to a main gear base 7 fixed on the support bracket 8, and a level adaptor 5. The level adaptor 5 has a gear rack portion 18, which interacts with the main gear 3. A tension spring 4 is provided for reducing the tolerance between the gear rack portion 18 of the level adaptor 5 and the main gear 3. The tray moving mechanism is initiated by a door open knob 12, which cooperates with a door lever 11 and is kept in a rest position by a plurality of compression springs 10. Located at the front of the disk module 9 is a pin 22, which interacts with a corresponding recess (not shown) of the level adaptor 5 for lowering the disk module 9 during an initial phase of operation of the tray moving mechanism.
An operating sequence of the tray moving mechanism is depicted in Figs. 2a) to d) . When the door open knob 12 is pressed (see Fig. 2a) ) , an arm lever 15 of the door lever 11 is moved and releases the level adaptor 5, thereby also releasing the torsion spring 6. This causes the main gear 3 to rotate, whereby the level adaptor 5 is moved in a direction perpendicular to a movement direction of the tray 13 (see Fig. 2b) ) . A pin 17 attached to the level adaptor 5 interacts with a corresponding recess 19 of the tray 13, which leads to an effective outward movement of the tray 13. The recess 19 has a first part 20 running parallel to the movement direction of the level adaptor 5, which does not cause any movement of the tray 13, and a second part 21 that is inclined relative to both the movement direction of the level adaptor 5 and the movement direction of the tray 13, which causes an initial outward movement of the tray 13. At the end of this initial outward movement the gear rack 16 of the tray 13 comes into contact with the main gear 3 (see Fig. 2c)) . The further rotation of the main gear 3 causes the tray 13 to be fully extracted of the player or recorder until a stopper (not shown) of the tray 13 comes into contact with a counterpart (not shown) of the support bracket 8 (see Fig. 2d) ) . The recess 19 of the tray 13
is designed such that there is no further interaction with the pin 17 of the level adaptor 5 once the interaction between the gear rack 16 and the main gear 3 has started. For moving the tray 13 back into the player or recorder, the user has to push the tray 13. Through the interaction between the gear rack 16 and the main gear 3 the torsion spring 6 is strained again. When the gear rack 16 loses the contact to the main gear 3, the recess 19 of the tray 13 starts to interact with the pin 17 of the level adaptor 5 and the level adaptor 5 is moved back into its rest position. At the same time through the interaction between the gear rack part 18 of the level adaptor 5 and the main gear 3 the torsion spring 6 is further strained. Finally the arm lever 15 locks the level adaptor 5 in the rest position. By carefully designing the diameter and center dimensions of the main gear base 7, the diameter and spring force of the torsion spring 6, and the dimension of the level adaptor 5 and the recess 19 of the tray 13 a motorized movement of the tray 13 is simulated. Of course, the gear ratio and a potential lubrication have to be taken into account as well.
As can be seen from the operating sequence, during the initial rotation of the main gear 3 by the spring 6 the pin 17 of the level adaptor 5 moves within the first part 20 of the recess 19 without causing any movement of the tray 13. In this phase the pin 22 of the disk module 9 interacts with the further recess (not shown) of the level adaptor 5 and the disk module 9 is lowered. When the pin 17 arrives at the second part 21 of the recess 19, the tray 13 is moved outward due to the inclination of the second part 21 of the recess 19. When the gear rack 16 of the tray 13 comes into contact with the main gear 3, the main gear 3 has already reached a constant speed and the tray 13 is moved smoothly outward.
In Figs. 3a) to c) some further views of the operating sequence of the tray moving mechanism are shown. When the tray 13 is locked in the player or recorder, the arm lever 15 locks the
level adaptor 5 in its rest position (see Fig. 3a) ) and the faceplate 14 (door) is closed. By pushing the door knob 12 the door lever 11 is moved a couple of millimeters and presses down the arm lever 15, thereby unlocking the level adaptor 5 (see left and right side of the bottom view of the mechanism in Fig. 3b)) . The faceplate 14 (door) is now open and the level adaptor 5 is moved by the rotation of the main gear 3 (see Fig. 3c) ) . Due to the interaction between the pin 17 of the level adaptor 5 and the corresponding recess 19 of the tray 13 the tray 13 is driven outward.
Fig. 4 illustrates the different forces acting in the tray moving mechanism. Fig. 4a) depicts the compression force exerted by the torsion spring 6, Fig. 4b) the tension force generated by the tension spring 4, Fig. 4c) the load weight of the disk module 9, Fig. 4d) the damping force applied to the system, and Fig. 4e) the friction force of the tray 13.