Abstract:
A recording medium loading mechanism for use in a signal processing apparatus has a motor which operates uni-directionally, and a power transmission mechanism operative to convert the rotation of the motor output shaft into reciprocating movements of a recording medium carrier between a loading position and a recording-reproducing position. The power transmission mechanism includes a crank pin (18) connected to the motor output shaft, a lost-motion connection for converting the rotational motion of the motor output shaft into reciprocal movements to move a reciprocating member (19), and cams cooperative with cam followers to transmit the reciprocating movements to the recording medium carrier.

Description:
This application is a continuation of application Ser. No. 07/193,675 filed May 13, 1988 now abandoned. 
    
    
     BACKGROUND OF THE INVENTION 
     The present invention relates to a disk-type signal processing apparatus which makes use of a disk-type recording medium such as a video disk, audio disk, optical disk and so forth. More particularly, the present invention is concerned with a recording medium loading mechanism for use in the disk-type signal processing apparatus of the type mentioned above, which is improved to simplify the mechanism of the apparatus and the electric circuit thereof. 
     Automatic loading devices for loading a recording medium, such as a disk cartridge, in a signal processing apparatus have been known from Japanese Utility Model Unexamined Publication Nos. 61-90052 and 60-146951. In general, the known loading device includes a cartridge holder portion, a driving motor with gears, and a driving power transmission. In particular, the driving power transmission includes a lot of component parts such as a link mechanism, a gear train, a power transmission shaft and so forth. The loading and unloading operation for loading and unloading the disk cartridge on and from the signal processing apparatus is effected by controlling the driving motor in forward and backward directions. Therefore, the driving circuit for the driving motor is required to have a protection circuit for checking the reverse current which is produced when the direction of the driving electric current is changed to reverse the driving motor. Furthermore, the mechanism sections which operate during the loading and unloading operations are made from materials having a high degree of reliability for longer operation, because only limited elements of these sections, such as the motor and gears, are actually used repeatedly. 
     As pointed out above, the known loading device has a driving power transmission having a larger number of component parts. This requires a complicated driving circuit for the driving motor as well as mechanical parts that have to be made from highly reliable materials. Satisfying these requirements runs contrary to the demands for reduction in the cost and size and for improvement in the reliability of disk players. 
     SUMMARY OF THE INVENTION 
     Accordingly, it is an object of the present invention to provide a recording medium loading mechanism of a structure which contributes to simplification of the mechanical and electrical systems of an associated signal processing apparatus and, thus, to reduce the number of the component parts and the cost of manufacture while improving the reliability of operation, thereby overcoming the prior art problems pointed out above. 
     According to one feature of the invention, there is provided a recording medium loading mechanism intended for use in a signal processing apparatus having a housing with an opening serving as an entrance and exist for a recording medium. The mechanism comprises a recording medium carrier mounted in the housing for movement between a first position for loading a recording medium into the carrier adjacent to the opening and a second position for at least one of recording and reproduction on the recording medium that is spaced from the opening. A uni-directionally operative motor is secured to the housing. The rotation of the output shaft of the motor is converted into reciprocal movements so that the carrier is moved between the first and second positions. 
     According to another feature of the invention, there is provided a loading mechanism for a cartridge accommodating a recording medium. The mechanism comprises a carrier with an opening for insertion of the cartridge. The carrier is drivingly connected to a movable member reciprocally movable in a plane substantially parallel to the direction in which the cartridge is inserted into and removed out of the carrier. The reciprocally movable member is driven by a uni-directionally operative motor. When the movable member is moved in a direction, the carrier is moved between a first position for insertion and removal of the cartridge into and out of the carrier and a second position for at least one of recording and reproduction on the recording medium in the cartridge. 
     The above and other objects, features and advantages of the present invention will be made more apparent by the following description with reference to the accompanying drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a schematic cross-sectional view of an embodiment of the present invention; 
     FIG. 2 is similar to FIG. 1, but illustrates a recording medium carrier in a recording/reproducing position; 
     FIG. 3 is a sectional view taken along the line III--III in FIG. 1; 
     FIG. 4 is an exploded perspective view illustrating various structural elements in their disassembled positions; and 
     FIG. 5 is a perspective view of a modified driving mechanism. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     A first embodiment of the present invention will be described hereinunder with reference to FIGS. 1 to 4. A recording/reproducing apparatus has a housing 8 which is provided with an opening 9 serving as an entrance and exit for a cartridge 1 accommodating a recording medium and formed in one side of the housing. The recording medium is a disk (not shown) housed in a cassette to form the cartridge 1. The housing 8 accommodates a recording medium loading mechanism which is generally designated by numeral 10. As shown in FIG. 1, the loading mechanism 10 has a recording medium carrier 12 which is moveable within the housing 8 between a loading position aligned with the opening 9 and a recording/reproducing position that is spaced downwardly from the opening 9. A base 14 is fixed to the inner surface of the bottom of the housing 8. A guide member 16 which has a generally U-shaped configuration as viewed in front elevation (FIG. 3) is fixed to the upper surface of the base 14. The guide member 16 has a pair of side walls 16a and a bottom wall 16b which interconnects one end of one of the side walls 16a to the adjacent end of the other side wall. A motor 17 is secured to the upper side of the bottom wall 16b. The lower half part of the motor 17 extends into the space in the base 14 through a window 16c formed in the bottom wall 16b and a similar window (not shown) provided in the upper wall of the base 14. 
     The motor 17 is disposed in such a manner that the axis of the output shaft thereof extends vertically, the output shaft being connected to the lower end of a crank pin 18. The upper end of the crank pin 18 extends upwards in an eccentric relationship to the output shaft of the motor 17. 
     The guide member 16 extends in parallel with the recording medium carrier 12 and horizontally movably receives a reciprocating member 19 of a configuration similar to that of the guide member 16. Thus, the member 19 has a pair of parallel side walls 19a and an intermediate portion 19b which interconnects one ends of these side walls 19a and 19a. The side walls 19a of the member 19 are held in sliding contact with the side walls 16a of the guide member 16 so that the reciprocating member 19 is movable horizontally along the guide member side walls 16a. An elongated slot 19c is formed in the intermediate portion 19c of the member 19 and has a longitudinal axis which extends substantially perpendicularly to the side walls 19a. The elongated slot 19c and the upper end of the crank pin 19 engage with each other in such a manner as to provide a lost motion. When the crank pin 18 is rotated by the output shaft of the motor 17, the reciprocating member 19 is reciprocatingly moved along the side walls 16a of the guide member 16. 
     Referring to FIG. 4, the recording medium carrier 12 has a substantially quadrilateral configuration having a first side 12a adjacent to the opening 9 of the housing 8, a second side 12b opposite to the side 12a, and third and fourth sides 12c and 12d which extend between the first and second sides 12a and 12b. The carrier 12 has a central window 12e. The first side 12a is provided with an entrance 12f which communicates with the window 12e. The carrier 12 is so sized that the third side 12c and the fourth side 12d are received between and moveable in sliding contact with both side walls 19a and 19a of the reciprocating member 19. Each side wall 19a of the reciprocating member 19 is provided with two spaced apart slanted cam surfaces 19d inclined relative to the direction of the reciprocating motion of the member 19. Pins 12h are secured through brackets 12g to the lower edges of the third and fourth sides 12c and 12d and project horizontally therefrom. The pins 12h of the recording medium carrier 12 engage with the reciprocating member 19 adjacent to the slanted cam surfaces 19d and extend horizontally outwardly beyond these cam surfaces. Vertical guide slots 16d for receiving the outer ends of the pins 12h are formed in the side walls 16a of the guide member 16. 
     The guide member 16 and the reciprocating member 19 are also of substantially U-shaped configuration as viewed in plan, defining therein spaces 16e and 19e vertically aligned with the window 12e in the recording medium carrier 12. 
     The carrier 12 is resiliently biased downwards by means of tension springs 21a and 21b which extend between the carrier 12 and the top wall of the base 14. 
     A circuit board 20 carrying electric circuits for driving and controlling the motor 17 is secured to the inner surface of the top wall of the housing 8 so as to extend horizontally above the recording medium carrier 12. 
     In operation, when the recording medium carrier 12 is in the loading position shown in FIG. 1, the entrance 12f in the carrier 12 is disposed adjacent to and in alignment with the opening 9 in the housing 8. It is therefore possible to insert or eject the cartridge 1 into and out of the carrier 12 through the opening 9 in the housing 8. When the carrier 12 is in the position shown in FIG. 1, the pins 12h of the carrier 12 engage the portions of the reciprocating members 19 near the upper ends of the slanted cam surfaces 19d. When the cartridge 1 is inserted into the carrier 12 from the exterior of the housing 8, a sensor (not shown) detects the cartridge 1 as having been fully inserted into the carrier 12. Upon receipt of the detection signal, the electric circuit carried by the circuit board 20 operates to drive the motor 17. When the motor starts to operate, the eccentric crank pin 18 engaging with the elongated slot 19c in the reciprocating member 19 causes the reciprocating member 19 to move in the direction of the arrow B in FIG. 1. 
     Consequently, the pins 12h provided on the carrier 12 are moved along the guide slots 16d in the guide member 16 by the forces of the springs 21a and 21b in the direction of the arrow A and, accordingly, the carrier 12 moves in the direction of the arrow A to set a disk in the cartridge 1 in the recording/reproducing position shown in FIG. 2. 
     The completion of the setting of the cartridge 1 in the recording/reproducing position is detected by a sensor (not shown), so that the driving motor 17 stops to operate, and the recording/reproducing apparatus operates its recording/reproducing mechanism (not shown) for a recording or reproduction of a signal in the disc of the cartridge 1. 
     The loading of the cartridge 1 is thus completed. An unloading operation is carried out as follows: 
     The rotation of the disk is stopped in response to a command from a commanding system when the recording or reproduction is finished in the position shown in FIG. 2. Upon detection of the stoppage of the rotation of the disk, the circuit carried by the driving circuit board 20 operates to drive the driving motor 17. The direction of rotation of the driving motor 17 is the same as that in the loading operation. As the driving motor 17 rotates, the reciprocating member 19 driven by the crank pin 18 moves in the direction counter to the arrow B, i.e., in the direction reverse to that in the loading operation. In consequence, the pins 12h on the carrier 12 are lifted by the cam surfaces 19d against the forces of the springs 21a and 21b and are moved along the guide slots 16d in the guide member 16 in the direction opposite to the arrow A in FIG. 1, thereby to cause the carrier 12 to move in the direction counter to the arrow A. When a sensor (not shown) senses the arrival of the carrier 12 at the ejecting position which is the same as the cartridge loading position, the driving motor 17 is stopped, so that the cartridge 1 is ready for ejection. As described above, the pins 12h are driven by the cam surfaces 19d, thus serving as cam followers. 
     In the described embodiment, the reciprocating member 19 is driven by means of the crank pin 18 which is connected to the output shaft of the driving motor 17. This arrangement, however, is only illustrative. In another embodiment shown in FIG. 5, a worm 23 is connected to the output shaft of the driving motor 17 and a worm wheel 24 engages with worm 23. A crank pin 18a is secured to one end surface of the worm wheel 24. In this embodiment, the motor 17 is disposed such that its axis extends horizontally, i.e., in parallel with the bottom of the housing 8, so that the housing 8 can be designed to have a reduced height. The use of the worm 23 and the worm wheel 24 makes it possible to obtain a necessary driving torque even from a motor of a smaller capacity. 
     In the embodiment described hereinbefore, the guide slots 16d have linear configurations to guide the carrier 12 linearly and vertically. This arrangement, however, may be modified and the shapes of the guide slots 16d can be determined freely in accordance with the positional relationship between the loading/ejecting position and the recording/reproducing position of the cartridge 1. It is possible to design such that the guide slots 16 have arcuate configurations so as to enable the carrier 12 to move two-dimensionally such that the movement of the carrier 12 has horizontal and vertical components. 
     The connection between the crank pin 18 and the reciprocating member 19 is not limited to the use of the elongated slot 19c. For instance, the arrangement may be such that the reciprocating member 9 is biased in only one direction by means of, for example, return spring while the force produced by the crank pin 18 acts only in the opposite direction. 
     It is also to be understood that, although the disk as the recording medium is housed in the cartridge 1 in the described embodiment, the arrangement may be modified in such a manner that the carrier 12 is used as a disk support and the disk is directly inserted into the carrier 12. In this case, the disk support 12 instead of the cartridge 1 supports the disk and is reciprocatingly moved between the loading position and the recording position. 
     As will be understood from the foregoing description, according to the present invention, it is possible to obtain a simple recording medium loading mechanism which is operable by a uni-directional operation of the driving motor to carry out loading and unloading of a recording medium. This advantage of the invention is not impaired even when the driving motor 17 is reversed for the purpose of, for example, an error recovery. 
     Since the loading and unloading are effected by the operation of the driving motor in the same direction, it is possible to simplify the construction of the driving and control circuit for the motor and also the construction of the mechanism for transmitting the torque of the motor to the carrier, thereby to reduce the size and cost and to improve the reliability of the recording medium loading device.