Disk loading apparatus

Abstract: The rotary motion of a driving cam (3) driven by a driving motor (1) is converted into both the upward and downward movement of a deck member (7) and the forward and backward movement of a tray (5), so that the deck memger (7) and the tray (5) can be driven by a single motor. Further, the conversion into the upward and downward movement of the deck member (7) and the forward and backward movement of the tray (5) is performed by the engagement of a pin (3b) of the driving cam (3) with a straight groove (4c) and a circular groove (4d) of a driving lever (4). Since the straight groove (4c) is extended in the tangential direction of the driving cam (3), when the pin (3b) engages with the straight groove (4c), the driving lever (4) receive a force to slow down the opening and closing speed of the tray (5) at the beginning and end of the movement, thereby improving the quality of the loading operation.

Description: FIELD OF THE INVENTION This invention relates to a disk loading apparatus for use in an optical disk player, such as a CD player, to bring a disk to a playing position of the disk player for playing the same. BACKGROUND OF THE INVENTION A conventional disk loading apparatus will be described with reference to the accompaying drawings. Figure 1 is a plan view of a mechanism for opening and closing a tray of the conventional disk loading apparatus. Reference numeral 9 denotes a tray driving motor and 5 denotes a tray. A rack 5b of the tray 5 is in mesh with a pinion 9a of the tray driving motor 9. Reference numerals 5c and 5d denote protrusions formed on the side surface of the tray 5 for serving to operate a tray position detector switch 10. Figure 2 is a side view of a mechanism for moving up and down a deck member 7. Reference numeral 6 denotes a base. Grooves 6a formed on both sides of the base 6 serve as a guide of movement of the tray 5 by slidably supporting projections 5g of the tray 5. On the other hand, a pin 7a provided on the deck member 7 for reading signals from a compact disk (referred to as CD, hereinafter) is put in a groove 6b so that the deck member 7 pivots about the pin 7a. Reference numeral 5e denotes a concave portion on which the CD is to be placed, and 5h denotes a hole for serving to prevent a turntable 7c from interfering with the tray 5 when the deck member 7 is moved upwards. Reference numeral 11 denotes a lifting motor the driving force of which is transmitted through a belt 2 to a lifting cam 12. The lifting cam 12 is formed in its side face with an inclined groove 12a with which a pin 7b provided on the deck member 7 is brought into engagement. Reference numeral 13 denotes a lift detector switch which serves to detect whether or not the deck member 7 has been raised to a predetermined position. With the above construction, when it is intended to load and play a CD, by putting the CD on the concave portion 5e of the tray in the first place and then driving the motor 9, the tray 5 is made to move in the direction of an arrow a shown in Figure 1. Therefore, the protrusion 5d operates the position detector switch 10 to thereby stop the motor 9. Subsequently, the motor 11 is driven to rotate the lifting cam 12 so that the pin 7b is caused to run up the inclined groove 12a and, hence, the deck member 7 is caused to pivot in the direction of an arrow g shown in Figure 2. When the turntable 7c of the deck member 7 is positioned in the hole 5h and the CD is lifted from the tray concave portion 5e until the upper end portion of the deck member 7 comes into contact with the detector switch 13, the detector switch 13 operates to stop the motor 11 and then the turntable 7c is rotated to play the disk. When it is intended to remove the CD which has finished playing, the lifting cam 12 is rotated in the direction reverse to the direction in which the cam 12 is rotated at the time of starting to play the CD, so that the deck member 7 is caused to pivot in the direction of arrow h shown in Figure 2. The motor 9 is also rotated in the direction reverse to the direction in which the motor 9 is rotated at the time of starting to play so as to make the tray 5 move in the direction of an arrow b shown in Figure 1, thereby permitting removal of the CD. However, with such conventional construction, it is necessary to use two motors since the movement of the tray and the upward and downward movement of the deck member depend on the independent separate driving systems, resulting in the problems of cost and reduction of size of the mechanism. Further, since it is necessary in connecting the respective movements to adjust timing delicately in consideration of the difference in mechanical loads, in order to reduce the speed of the tray as low as possible at each end of the opening and closing operation of the tray so as to improve the quality of the movement, it is also necessary to take measures in respect of the electric circuit so as to keep the rotational frequency of the motor under complicated servocontrol. EP-A-0 416 797, being state of the art according to Article 54(3) EPC, discloses a disk loading apparatus in which a driving motor drives a driving cam which drives a pinion. The disk tray is provided with a groove, a first segment of it being rectilinear and a second segment of it being circular and formed continuously to the first segment, the two segments together forming a J-shaped groove. The tray has also a toothed rack of the same J-shape cooperating with the pinion. When the tray is in its fully retracted position the rotation axis of the cam coincides with the center of the circular segment of the groove in the tray. This arrangement makes it possible that the cam and the pinion form a planetary gear with the cam as the sun wheel. SUMMARY OF THE INVENTION The present invention aims at solving the above problems, and an object thereof is to provide a disk loading apparatus which is capable of performing the movement of a tray and the upward and downward movement of a deck member at good timing with accuracy so as to assure a loading operation of high quality. To this end, there is provided according to the present invention a disk loading apparatus which comprises a driving motor, a driving cam rotatably connected with said driving motor through a transmission member and having an engaging portion, a driving lever formed therein with a groove for engagement with said engaging portion of said driving cam and associated with a movement of said driving cam about a center of rotation thereof which is offset from a center of rotation of said driving cam, a tray associated with the movement of said driving lever and moveable back and forth with a disk carried thereon, and a deck member associated with the movement of said driving cam and moveable up and down and reading signals from said disk, and in which said groove comprises a first rectilinear groove segment extending in the tangential direction of said driving cam and a second circular groove segment formed continuously to said first groove segment and extending in the direction of rotation of said driving cam, the first and second groove segments together forming a J-shaped groove. In accordance with such construction, the rotary motion of the driving cam driven by the driving motor is converted into both the upward and downward movement of the deck member and the forward and backward movement of the tray, and furthermore, the conversion into the forward and backward movement is performed by the engagement of the pin of the driving cam with the first and second groove segments of the driving lever. By the engagement of the pin with the first groove segment, the opening and closing speed of the tray can be slowed down at the end of the opening and closing movement of the tray, thereby making it possible to improve the quality of the loading operation by this simple mechanical construction. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a plan view of a conventional disk loading apparatus; Figure 2 is a side view of the conventional disk loading apparatus; Figure 3 is a plan view of a disk loading apparatus according to an embodiment of the present invention; Figures 4A, 4B, and 4C are plan views showing the operating states of a driving lever of the disk loading apparatus; and Figure 5 is a side view of the disk loading apparatus. DESCRIPTION OF THE PREFERRED EMBODIMENT Description will be given below of a disk loading apparatus according to an embodiment of the present invention. Figure 3 is a plan view of a tray opening and closing mechanism of the disk loading apparatus of the invention, Figure 4 illustrates the principle of the movement of a driving lever of the apparatus, and Figure 5 is a side view of a deck member lifting mechanism of the disk loading apparatus of the invention. Reference numeral 1 denotes a driving motor, 2 denotes a belt serving to transmit the turning force from the driving motor 1, and 3 denotes a driving cam to which the turning force from the driving motor 1 is transmitted through the belt 2. The driving cam 3 has an inclined groove 3a, a pin 3b and a projection 3c formed respectively in its side surface, on its top surface and on its upper side surface. Reference numeral 4 denotes a driving lever having an axis of rotation 4b located in a position different from a position of a center of rotation 3d of the driving cam 3. The driving lever 4 is formed with a J-shaped groove 4a in a position facing the top surface of the driving cam 3 so that the pin 3b of the driving cam 3 is made to slidably engage with the J-shaped groove 4a. The J-shaped groove 4a consists of a straight groove 4c extended in the tangential direction of the driving cam 3 and of a circular groove 4d formed continuously with the straight groove 4c so as to extend in the direction of rotation of the driving cam 3. A pin 4e is provided at one end of the driving lever 4. Reference numeral 5 denotes a tray which reciprocates with a disk carried thereon. The tray 5 is formed at one end thereof with a slot 5a for slidable engagement with the pin 4e of the driving lever 4, and a hole 5i is formed in a part of the tray 5. Reference numeral 6 denotes a base. Grooves 6a formed on both sides of the base 6 serve as a guide for movement of the tray 5 by slidably supporting projections 5g of the tray 5. Reference numeral 7 denotes a deck member one end of which is rotatably pivotted to an end portion of the base 6 and the other end of which is formed with an engaging piece 7d for engagement with the inclined groove 3a of the driving cam 3. A turntable 7c is formed in an upper part of the deck member 7 so as to be positioned in the hole 5i of the tray when the deck member 7 is moved upwards. Reference numeral 8 denotes a position detector switch provided on the base 6. The position detector switch 8 has a switch piece 8a which comes into contact with the projection 3c of the driving cam 3 when the driving cam 3 is rotated to a predetermined position. Operation of the disk loading apparatus according to an embodiment of the present invention which has the above-described construction will be described below. First, as the motor 1 is rotated counterclockwise for moving the tray 5 in the direction of arrow b of Figure 3 in order to bring the tray 5 into its fully opened state, the driving cam 3 is rotated in the direction of arrow f through the driving belt 2 and the pin 3b is also rotated in the same direction as the driving cam 3. Therefore, the state of engagement between the pin 3b and the J-shaped groove 4a of the driving lever 4 is changed from a state of Figure 4(B) to a state of Figure 4(A). In this case, the pin 3b is rotated about the axis of rotation 3d of the driving cam 3. However, once the pin 3b passes along the circular groove 4d and enters the straight groove 4c, and on further movement of the pin 3b in the direction of rotation of the driving cam 3 the pin 3b exerts a force on the driving lever 4, which force causes the lever 4 to pivot about axis 4b, thus causing the radial center of the circular groove 4d and the center of rotation of the driving cam 3 to become offset. Consequently, the tray 5 is moved in the direction of arrow b of Figure 3 due to engagement between the pin 4e and the slot 5a and the speed at which the tray 5 is opened is firstly accelerated and then continuously slowed down as the tray 5 is brought to its opened state (see Figure 4(A)). Subsequently, as the motor 1 is rotated clockwise with the tray 5 carrying a CD thereon, the driving cam 3 is rotated clockwise. However, since the pin 3b is moving in the straight groove 4c the pin 3b exerts a force on the driving lever 4. Consequently, the tray 5 is moved in the direction of arrow a of Figure 3 due to engagement between the pin 4e and the slot 5a and the speed at which the tray 5 is closed is continuously slowed down as the tray 5 is brought to its closed state (see Figure 4(B)). Further rotation of the driving cam 3 from the state of Figure 4(B) causes the pin 3b to rotate clockwise along the circular groove 4d of the J-shaped groove 4a. When the radial center of the circular groove 4d and the center of rotation 3d of the driving cam 3 coincide with each other again, the driving lever 4 no longer receives a force. Rotation of the pin 3b along the circular groove 4d causes the deck member 7 to move upwards in the direction of arrow g of Figure 5 due to engagement between the inclined groove 3a of the driving cam 3 and the engaging piece 7d of the deck number 7. When the pin 3b arrives at the forward end of the circular groove 4d as shown in Figure 4(C), the projection 3c of the driving cam 3 comes into contact with the switch piece 8a of the position detector switch 8, so that the rotation of the driving cam 3 is stopped. In this state, the deck member 7 is fully lifted and the turntable 7c is positioned in the hole 5i of the tray 5 with the CD held thereon, thus completing the loading operation. Next, when it is intended to remove the CD, counterclockwise rotation of the motor 1 causes the driving cam 3 to rotate in the same direction, so that the pin 3b is rotated from the position of Figure 4(C) to the position of Figure 4(B). During this rotation, since the radial center of the circular groove 4d and the center of rotation 3d of the driving cam 3 coincide with each other as described above, only the deck member 7 is moved downwards in the direction of arrow h of Figure 5 without any force being applied to the driving lever 4. As the pin 3b is further rotated from the position of Figure 4(B), the pin 3b again engages with the straight groove 4c, so that the pin 3b exerts a force on the driving lever 4, whereby the radial center of the circular groove 4d and the center rotation of the driving cam 3 become offset. Consequently, the tray 5 is moved in the direction of arrow b of Figure 3 with the speed being slowed down at the end of the movement thereof until it is brought to its opened state. Thereafter, the CD can be removed from the tray 5. As described hereinabove, according to the disk loading apparatus of this embodiment it is possible to drive both the deck member 7 and the tray 5 by the driving motor 1 alone. In particular, the rotary motion of the driving cam 3 is divided to provide the forward and backward movement of the tray 5 and the upward and downward movement of the deck member 7. That is to say, when the pin 3b of the driving cam 3 is engaged with the straight groove 4c of the J-shaped groove 4a, the tray 5 only is moved and when the pin 3b is engaged with the circular groove 4d, the deck member 7 only is moved. Further, when the pin 3b engages with the straight groove 4c, and therefore, the driving lever 4 receives a force, the speed of the opening and closing movement of the tray 5 is accelerated at the beginning of said movement and it is slowed down at the end thereof, thereby improving the quality of the loading operation.

Claims: A disk loading apparatus comprising: a driving motor (1); a driving cam (3) rotatably connected with said driving motor (1) through a transmission member (2) and having an engaging portion (3b); a driving lever (4) formed therein with a groove (4a) for engagement with said engaging portion (3b) of said driving cam (3) and associated with a movement of said driving cam (3) about a center of rotation (4b) thereof which is offset from a center of rotation (3d) of said driving cam (3); a tray (5) associated with the movement of said driving lever (4) and moveable back and forth with a disk carried thereon; and a deck member (7) associated with the movement of said driving cam (3) and moveable up and down and reading signals from said disk, wherein said groove (4a) comprises a first rectilinear groove segment (4c) extending in the tangential direction of said driving cam (3) and a second circular groove segment (4d) formed continuously to said first groove segment (4c) and extending in the direction of rotation of said driving cam (3), the first and second groove segments together forming a J-shaped groove. A disk loading apparatus according to Claim 1, wherein said driving cam (3) has an inclined groove (3a) in a side surface thereof and said deck member (7) has a pin (7b) for engagement with said inclined groove (3a). A disk loading apparatus according to Claim 1 or 2, further comprising a switch (8) which serves to detect completion of the upward movement of said deck member (7) so as to stop the driving cam (3).

Inventors: KANEO TOSHIHIRO, KIMURA SOICHI, MORIMOTO YOSHITSUGU, SUGAHARA SHINYA, KANEO, TOSHIHIRO, KIMURA, SOICHI, MORIMOTO, YOSHITSUGU, SUGAHARA, SHINYA
Applicants: MATSUSHITA ELECTRIC IND CO LTD, MATSUSHITA ELECTRIC INDUSTRIAL CO., LTD.
Application year: 1991
Main classification: G11B17
IPC codes: G11B17