Locking mechanism of disk device

1. A locking mechanism of a disk device, mounted in between a tray for holding and conveying a disk as an information recording medium and a casing for housing the tray to be capable of being inserted and ejected, comprising:

a locking pin mounted on either one of members out of the casing or the tray; a locking lever with a locking part on the tip to be engaged with the locking pin, which is held to be capable of oscillating by the other member out of the casing or the tray; and

an ejection lever mounted to be capable of oscillating for keeping or releasing the engagement between the locking pin and the locking part by energizing a prescribed oscillation movement to the locking lever; and a holding unit for keeping the engagement between the locking pin and the locking part through holding one end of the ejection lever against the energizing force in the opposite direction which is normally set beforehand; wherein

a balance weight is mounted on the opposite side to the ejection lever with respect to the oscillation center of the ejection lever.

2. The locking mechanism of a disk device as claimed in claim 1 , further comprising a reset lever, wherein:

the reset lever oscillates the ejection lever by being pressed by the locking pin when the tray is ejected from the casing, and moves one end of the ejection lever to a position to be held by the holding unit.

3. A locking mechanism of a disk device for housing a tray inside a casing, which is provided in the tray for holding a disk to be an information recording medium and the casing for housing the tray to be capable of being inserted and ejected, comprising:

a locking pin mounted on either one of members out of the casing or the tray; while comprising:

on the other member out of the casing or the tray, a locking lever having a locking part on the tip to be engaged with the locking pin, which is supported to be capable of oscillating; an ejection lever supported to be capable of oscillating for pressing a prescribed part of the locking lever so as to oscillate the locking lever in such a direction that the locking part is detached from the locking pin; and a holding unit for holding a movable piece provided on one end of the ejection lever so as to set aside the ejection lever to such a position that the ejection lever does not press the locking lever; wherein

a balance weight having a prescribed weight is provided on the opposite side to the center of the gravity of the ejection lever with respect to the oscillation center of the ejection lever.

4. The locking mechanism of a disk device as claimed in claim 3 , wherein the balance weight is a balancer provided to the ejection lever for setting the center of the gravity of the ejection lever to be in the oscillation center of the ejection lever or the vicinity.

5. The locking mechanism of a disk device as claimed in claim 3 , wherein a balance weight having a prescribed weight is provided on the opposite side to the center of the gravity of the locking lever with respect to the oscillation center of the locking lever.

6. The locking mechanism of a disk device as claimed in claim 5 , wherein the balance weight is a balancer provided to the locking lever for setting the center of the gravity of the locking lever to be in the oscillation center of the locking lever or the vicinity.

7. The locking mechanism of a disk device as claimed in any one of claims 3 , further comprising a reset lever being supported to be capable of oscillating while a part of which is being linked with the ejection lever, which comes to be in slide-contact with the locking pin due to a position shift generated between the tray and the casing by the inserting and ejecting action of the tray, and thereby receives pressuring force from the locking pin to oscillate the ejection lever so that the movable piece comes to be in contact with the holding unit.

8. The locking mechanism of a disk device as claimed in claim 7 , wherein a balance weight having a prescribed weight is provided on the opposite side to the center of the gravity of the reset lever with respect to the oscillation center of the reset lever.

9. The locking mechanism of a disk device as claimed in claim 8 , wherein the balance weight is a balancer provided in the reset lever for setting the center of the gravity of the reset lever to be in the oscillation center of the reset lever or the vicinity.

10. The locking mechanism of a disk device as claimed in claim 3 , further comprising an emergency ejection lever being supported to be capable of oscillating while a part of which is being linked with the locking lever, which is oscillated by an external manual operation while energizing a torque to the locking lever, and thereby oscillates the locking lever in such a direction that the locking part of the locking lever is detached from the locking pin.

11. The locking mechanism of a disk device as claimed in claim 10 , wherein a balance weight having a prescribed weight is provided on the opposite side to the center of the gravity of the emergency ejection lever with respect to the oscillation center of the emergency ejection lever.

12. The locking mechanism of a disk device as claimed in claim 11 , wherein the balance weight is a balancer provided in the emergency ejection lever for setting the center of the gravity of the emergency ejection lever to be in the oscillation center of the emergency ejection lever or the vicinity.

13. A locking mechanism of a disk device for housing a tray inside a casing, which is provided in the tray for holding a disk to be an information recording medium and the casing for housing the tray to be capable of being inserted and ejected, comprising:

a locking pin mounted on either one of members out of the casing or the tray; while comprising:

on the other member out of the casing or the tray, a locking lever having a locking part on the tip to be engaged with the locking pin, which is supported to be capable of oscillating; an ejection lever supported to be capable of oscillating for pressing a prescribed part of the locking lever so as to oscillate the locking lever in such a direction that the locking part is detached from the locking pin; and a holding unit for holding a movable piece provided on one end of the ejection lever so as to set aside the ejection lever to such a position that the ejection lever does not press the locking lever; wherein

a balance weight having a prescribed weight is provided on the opposite side to the center of the gravity of the locking lever with respect to the oscillation center of the locking lever.

14. A locking mechanism of a disk device for housing a tray inside a casing, which is provided in the tray for holding a disk to be an information recording medium and the casing for housing the tray to be capable of being inserted and ejected, comprising:

a locking pin mounted on either one of members out of the casing or the tray; while comprising

on the other member out of the casing or the tray, a locking lever having a locking part on the tip to be engaged with the locking pin, which is supported to be capable of oscillating; an ejection lever supported to be capable of oscillating for pressing a prescribed part of the locking lever so as to oscillate the locking lever in such a direction that the locking part is detached from the locking pin; a holding unit for holding a movable piece provided on one end of the ejection lever so as to set aside the ejection lever to such a position that the ejection lever does not press the locking lever; and a reset lever being supported to be capable of oscillating while a part of which is being linked with the ejection lever, which comes to be in slide-contact with the locking pin due to a position shift generated between the tray and the casing by the inserting and ejecting action of the tray, and thereby receives pressuring force from the locking pin to oscillate the ejection lever so that the movable piece comes to be in contact with the holding unit, wherein

a balance weight having a prescribed weight is provided on the opposite side to the center of the gravity of the reset lever with respect to the oscillation center of the reset lever.

15. A locking mechanism of a disk device for housing a tray inside a casing, which is provided in the tray for holding a disk to be an information recording medium and the casing for housing the tray to be capable of being inserted and ejected, comprising:

a locking pin mounted on either one of members out of the casing or the tray; while comprising:

on the other member out of the casing or the tray, a locking lever having a locking part on the tip to be engaged with the locking pin, which is supported to be capable of oscillating; an ejection lever supported to be capable of oscillating for pressing a prescribed part of the locking lever so as to oscillate the locking lever in such a direction that the locking part is detached from the locking pin; a holding unit for holding a movable piece provided on one end of the ejection lever so as to set aside the ejection lever to such a position that the ejection lever does not press the locking lever; and an emergency ejection lever being supported to be capable of oscillating while a part of which is being linked with the locking lever, which is oscillated by an external manual operation while energizing a torque to the locking lever, and thereby oscillates the locking lever in such a direction that the locking part of the locking lever is detached from the locking pin, wherein

a balance weight having a prescribed weight is provided on the opposite side to the center of the gravity of the emergency ejection lever with respect to the oscillation center of the emergency ejection lever.

16. A locking mechanism of a disk device for housing a tray inside a casing, which is provided in the tray for holding a disk to be an information recording medium and the casing for housing the tray to be capable of being inserted and ejected, comprising:

a locking pin mounted on either one of members out of the casing or the tray; while comprising:

on the other member out of the casing or the tray, a locking lever having a locking part on the tip to be engaged with the locking pin, which is supported to be capable of oscillating; a locking lever movable unit to be engaged with the other end portion of the locking lever for oscillating the locking lever in such a direction that the locking part is detached from the locking pin; wherein

a balance weight having a prescribed weight is provided on the opposite side to the center of the gravity of the locking lever with respect to the oscillation center of the locking lever.

17. The locking mechanism of a disk device as claimed in claim 16 , wherein the balance weight is a balancer provided in the locking lever for setting the center of the gravity of the locking lever to be in the oscillation center of the locking lever or the vicinity.