# Patent

## Title
Optical recording medium having substrate of dual transparent layers

## Abstract

Provision of a disc loading apparatus for a disc player, which permits a disc being inserted to be safely pulled out without being held between a turntable and a clamper. A clamper supporting member having an engagement portion carries the clamper, and a stopper is disposed on the line of movement of the engagement portion. The stopper is normally at a preventing position of being in contact with the engagement portion to prevent the clamper from approaching the turntable. When a disc has been inserted up to a position that it can be held on the turntable, it pushes the stopper to an approach allowable position to allow the clamper to approach the turntable. When the clamper approaches the turntable, the stopper is pushed by the engagement portion of the clamper supporting member to a retreated position, at which the stopper is out of contact with the disc.

## Background
1. Field of the Invention

This invention relates to a disc loading apparatus for a disc player, in which an imperfectly inserted disc is not clamped between a turntable and a clamper.

2. Description of the Prior Art

In a usual disc loading apparatus for a disc player, in response to the sending of a disc from the outside, a clamper is automatically caused to approach a turntable, thus holding the disc on the turntable with the clamper to be ready for playing the disc.

In such an apparatus, sometimes the user may intend in fluster to pull out a disc which is being inserted. In such a case, the disc may not be completely pulled out but be held on the turntable by the clamper automatically caused to approach the turntable. If it is intended to pull out the disc irrationally in such a case, it is possible to cause damage to the disc and also to the internal mechanism.

The present invention seeks to solve the above problem, and its specific object is to provide a disc loading apparatus for a disc player in which, in response to the sensing of insertion of a disc, a clamper is caused to approach a turntable and hold the disc on the turntable, and pulling out the disc after the start of approach of the turntable by the clamper, brings about an operation of preventing the clamper from approaching the turntable, thus preventing otherwise possible damage to the disc and the internal mechanism of the disc player.

Another object of the invention is to prohibit, when a disc is held on the turntable, double insertion of other disc by mistake, thus preventing otherwise possible damage to the discs and the internal mechanism.

According to the invention, the clamper is carried by a clamper supporting member having an engagement portion, and a stopper is disposed on the line of movement of the engagement portion. The stopper is normally at a preventing position of being in contact with the engagement portion to prevent the clamper from approaching the turntable. When a disc has been inserted up to a position that it can be held on the turntable, the stopper is pushed by the disc to an approach allowable position to allow the clamper to approach the turntable. When the clamper approaches the turntable, the stopper is pushed by the engagement portion from the approach allowable position to a retreated position, at which the stopper is out of contact with the disc.

Thus, when a disc being inserted is pulled out in fluster, the stopper prevents the clamper from approaching the turntable, thus preventing damage to the disc and the internal mechanism. When the disc is normally inserted, it pushes the stopper to the approach allowable position, thus permitting normal operation of the clamper. Besides, since the stopper is separated from the disc by the engagement portion while the clamper approaches the turntable, the disc can be turned without possibility of being obstructed by the stopper.

With this arrangement, since the stopper is separated from the disc with sliding of the engagement portion along a sliding contact portion which is provided on the stopper, the stopper can be separated form the disc with a simple construction.

The same effects are also obtainable with a converse arrangement that the sliding contact portion is provided on the engagement portion and caused to slide along the stopper.

Furthermore, a double insertion prohibiting member may be provided, which is interlocked to the stopper such that it is normally out of the passage of the disc and, when stopper is pushed by the engagement portion of the clamper supporting member to the retreated position, it appears on the passage of the disc and prohibits the insertion of the disc. With this arrangement, the double insertion of disc can be prohibited with a simple construction.

The invention will become more apparent upon a reading of the following detailed specification with reference to the accompanying drawings, in which:

FIG. 1 is a perspective view showing an embodiment of the disc player according to the invention;

FIG. 2 is a plan view showing the internal construction of a playing unit in the disc player:

FIG. 3 is a plan view showing the playing unit;

FIG. 4 is a left side view showing the internal construction of the playing unit;

FIG. 5 is a right side view showing the same;

FIG. 6 is a front view, partly in section, showing the playing unit;

FIG. 7 is a front view showing the same with a disc loaded therein;

FIG. 8 is a plan view showing a transfer apparatus;

FIG. 9 is a view for describing the shapes of end portions of a push-forth and a push-back member and an elastic holding mechanism;

FIG. 10 is a perspective view showing the relation between the push-back member and a turntable;

FIG. 11 is a plan view showing the transfer apparatus;

FIG. 12 is a view similar to FIG. 11 but showing the transfer apparatus in a different state;

FIG. 13 is a view similar to FIG. 11 but showing the transfer apparatus in a further state;

FIG. 14 is a perspective view showing the relation between a rotation member and an idler gear;

FIGS. 15A, 15B, 15C, 15D, and 15E are plan views showing the relation between the push-back member and a holding member;

FIG. 16 is a side view showing the relationship among the rotation member, the push-back member and a switch;

FIG. 17 is a fragmentary perspective view showing an elastic holding mechanism;

FIG. 18 is a view for describing the range of disc, in which the disc can be held by the elastic holding mechanism;

FIG. 19 is a sectional view showing the relation between the turntable and a clamper;

FIG. 20 is a perspective view showing a stopper;

FIGS. 21A, 21B and 21C are elevational views showing the relation between the stopper and a clamper supporting member;

FIG. 22 is a front view showing the relation between a slide and a double insertion prohibit member;

FIG. 23 is a front view showing the relation between the slide and the double insertion prohibit member;

FIG. 24 is a view for describing the timings of the start and stop of a one-direction motor;

FIG. 25 is a plan view showing the disc player with a disc taken out during transfer thereof;

FIG. 26 is a plan view showing the relation among the push-forth and push-back members and the stopper;

FIG. 27 is also a plan view showing the relationship among the push-forth and push-back members and the stopper; and

FIG. 28 is a plan view showing the relationship among the rotation member, the idler gear and the push-forth and push-back members.

FIG. 1 is a perspective view showing a car-mounted disc player. The disc player has a cabinet 1, which accommodates a playing unit 2 mounted in it via a clamper (not shown). The cabinet 1 has a disc insertion slot 3 formed in its front surface.

FIG. 2 is a plan view showing the playing unit in an initial state thereof when a disc D is inserted from the disc insertion slot 3 or in a state when the disc D is pushed back from a playing portion P of the playing unit 2 toward the disc insertion slot 3. FIG. 3 is a plan view showing the playing unit in a state when the disc D is loaded in the playing portion P. As shown in FIGS. 1 and 3, the top of the playing unit 2 is covered by a ceiling plate 2a and a clamper supporting member 4. In FIG. 2, the ceiling member 2a and the clamper supporting member are not shown.

FIGS. 4 and 5 are a left side and a right side view, respectively, showing the internal construction of the playing unit 2. The playing portion P is disposed in a central part of the playing unit 2, and includes a turntable 5, a clamper 6, a motor 7 and a pick-up 8 (see FIG. 2). In the playing unit P, the disc D is held on the turntable 5 by the clamper 6, and the turntable 5, the clamper 6 and the disc D are driven to be rotated in unison with one another by a motor 7 for playing back data recorded in the disc D with the pick-up 8.

The playing portion P is disposed near the disc insertion slot 3 for playback with the disc D at a position, which is assumed when the entirety of the disc D is inserted slightly from the disc insertion slot 3 (see FIG. 3).

FIGS. 6 and 7 are front views, partly broken away, of the playing unit 2, which show a state that the disc D is not loaded and also show an initial state that the disc D is inserted, respectively. A passage 9 of disc D continuing from the disc insertion slot 3, is formed in a synthetic resin portion constituting a front end portion of the playing unit 2. The upper wall surface of the passage 9 has upward inclined surface portions 9a adjacent to and extending from the opposite edges of the passage 9. The lower wall surface of the passage 9, on the other hand, has downward inclined surface portions 9b in the like locality.

As shown in FIGS. 2 and 8, a transfer means 10 is disposed on one side of the passage 9 of the disc D (i.e., left side of the playing unit 2). The transfer means 10 includes a push-forth member 11 disposed near the disc insertion slot 3, a push-back member 12 disposed rearwardly thereto, and a connecting member 13 connecting the push-forth and push-back members 11 and 12 to each other. The push-forth member 11 and the connecting member 13 are elastically made integral by the spring 14 with their facing portions 11a and 13a in contact with each other. The facing portions 11a and 13a can be separated from each other against the force of the spring 14. The push-forth member 11, the connecting member 13 and the spring 14 together constitute a main push member 15.

A driving means 16 is disposed on the left side in the playing unit 2 and rearwardly of the push-back member 12. The driving means 16 includes a rotation member 17, an idler gear 18 and a one-direction motor 19 as a drive source, and can reciprocally drive the push-back member 12.

The push-back member 11 and the connecting member 13 are rockably mounted on a common shaft 20a, and the push-back member 12 is rockably mounted on another shaft 20b.

As shown in FIG. 9, rockable ends of the push-forth and push-back members 11 and 12 have a disc push portion 21, in a V-shaped form when viewed sidewise, and a first disc receiving portion 22a, respectively. As shown in FIG. 8, the push-back member 12 has another disc receiving portion, i.e., a second disc receiving portion 22b, also having a V-shaped form, between the center of its rocking and the first disc receiving member 11 is at a receiving position to receive the insertion of the disc, the disc push portion 21 is at a position near the left end of the disc insertion slot 3, the push-back member 12 is at a waiting position for being in contact with the edge of the disc D inserted from the disc insertion slot 3, and the first and second disc receiving portions 22a and 22b are located above the turntable 5 (FIGS. 8 and 10).

As shown in FIG. 8, the push-back member 12 has a cam groove 23 formed spirally around the center of its rocking. The connecting member 13 has a cam pin 24, which is received in the cam groove 23, the cam groove 23 and the cam pin 24 thus constituting a cam mechanism 25. The cam groove 23 has an inclined groove portion formed as a separating portion 23a adjacent its end closer to the center of rocking. When the disc D is not inserted, the cam pin 24 is at its position as shown in FIG. 8, near the end of the cam groove 23 closer to the center of rocking of the push-back member 12. When the disc D is inserted to cause rocking of the push-back member 12 rearwardly of the playing unit 2, the cam pin 24 is moved along the cam groove 23 toward the other end thereof, as shown in FIGS. 11 and 12, thereby causing the connecting member 13 to follow the push-back member 12 and rock. When the cam pin 24 is moved to the separating portion 23a, as shown in FIG. 13, the connecting member 13 is slightly pushed back. When the connecting member 13 rocks about the shaft 20a, the push-forth member 11 also rocks about the shaft 20a in unison with the connecting member 13.

Reference numeral 26 in FIG. 2 designates a disc guide, which is formed such that it is integral with a synthetic resin portion constituting a front end portion of the playing unit 2. An orbit of transfer of the disc D is set with the edge thereof in contact with the disc guide 26.

As shown in FIG. 8, the push-back member 12 has a gear portion 27, a contact portion 28 and a spiral pressure receiving portion 29, these portions being formed around the center of its rocking.

As shown in FIG. 14, the rotation member 17 has a spur gear 30 formed in its lower portion and a partial gear 31 formed in its upper or remaining portion and having teeth formed only in an angular range of about 100 degrees. The torque of the motor 19 is transmitted via a worm gear 19a mounted on the motor shaft, a worn wheel 32 and a first and a second speed reduction gear 33a and 33b to the spur gear 30. The partial gear 31 can be selectively meshed with the idler gear 18, which in turn is always in mesh with the gear portion 27 of the push-back member 12. The worm wheel 32 and the first and second speed reduction gears 33a and 33b constitute the driving means 16 together with the rotation member 17 and the idler gear 18.

As also shown in FIG. 14, from the top surface of the rotation member 17 is projected a push member 35, which has a clamper control cam 34 formed by recessing a portion of its top surface. The rotation member 17 also has a first and a second angular hole 36a and 36b which is formed to penetrate the rotation member 17. The push member 35 has a push portion 37 coincident with the radial direction of the rotation member 17 and also a first and a second arcuate surface 38 and 39 continuous in succession from the push portion 37. When the disc D is not inserted, the contact portion 28 of the push-back member 12 is out of the orbit of rocking of the push portion 37, but when the push-back member 12 is pushed by the disc D and caused to rock, it is brought to the orbit of rocking of the push portion 37, as shown in FIG. 11.

With clockwise rotation of the rotation member 17 caused in this state, the push portion 37 pushes the contact portion 28 of the push-back member 12 and causes rocking thereof rearwardly of the playing unit 2, i.e., in the counterclockwise direction. As the rotation of the rotation member 17 proceeds, the push portion 37 is eventually separated from the contact portion 28, and subsequently the first arcuate surface 38 is brought into contact with the contact portion 28, as shown in FIG. 12. During this time, the push-back member 12 is held at a fixed position. As the rotation of the rotation member 17 further proceeds, the second arcuate surface 39 replaces the first arcuate surface 38 and is brought into contact with the contact portion 28. At this time, the push-back member 12 is again pushed rearwardly. While the second arcuate surface 39 is in contact with the contact portion 28, the push-back member 12 is held at a fixed position.

As shown in FIG. 8, a push member 40 is rockably mounted by a shaft 40a to the underside of the push-back member 12. The push member 40 has a push pin 40b provided at its rockable end, and it is always pushed by a spring 41 against the outer periphery of the pressure receiving portion 29 of the push-back member 12.

As shown in FIGS. 15A to 15E, the pressure receiving portion 29 has a locking portion 29a for being in contact with the push pin 40b and thus locking the push-back member 12 at the end position of clockwise rocking, a first pressure receiving surface 29b progressively more distant from the center of rocking in the clockwise direction from the locking portion 29a, a second pressure receiving surface 29c for being progressively closer to the center of rocking from the first pressure receiving surface 29b, and an arcuate surface 29e spaced apart from the second pressure receiving surface 29c by a step 29d.

When the push pin 40b is held pushed against the first pressure receiving surface 29b, its pushing force acts to cause clockwise rocking of the push-back member 12. Before the disc insertion, as shown in FIG. 15A, the locking portion 29a is in contact with the push pin 40b and thus prohibiting clockwise rocking of the push-back member 12, and the push-back member 12 is held at its initial position by the pushing force of the push pin 40b received by the locking portion 29a.

When the disc D is inserted form the disc insertion slot 3, the push-back member 12 is pushed by the disc D and, as shown in FIG. 15B, rocks in the counterclockwise direction while pushing back the push pin 40b with the first pressure receiving surface 29b.

When the second pressure receiving surface 29c replaces and is brought into contact with the push pin 40b, as shown in FIG. 15C, the pushing force of the push pin 40b exerted to the second pressure receiving surface 29c acts to cause counterclockwise rocking of the push-back member 12.

When the push pin 40b is brought from the second pressure receiving surface 29c via the step 29d as shown in FIG. 15D to the arcuate surface 29e, as shown in FIG. 15E, the pushing force of the push pin 40b exerts no rocking force to the push-back member 12 in either direction.

As shown in FIG. 16, a first switch 42a is disposed below the push-back member 12, and a second switch 42b is disposed below the rotation member 17. In FIG. 16, reference numeral 42 designate a printed circuit board. Although not shown, an ejection switch is further provided, which is operated by the disc unloading operation. These switches are provided for controlling the one-direction motor 19. The first switch 42a is turned on when it is pushed by the pressure receiving portion 29 of the push-back member 12. The second switch 42b is held "off" when it is in the first or second angular hole 36a or 36b, and is turned on when it is detached from the angular hole 36a and 36b and pushed by the bottom surface of the rotation member 17.

As shown in FIGS. 2, 3, 6 and 7, an elastic holding mechanism 43 is provided in the front end portion of the playing unit 2. The elastic holding mechanism 43 is constituted by a pair of elastic retainers 44 disposed symmetrically above and on the opposite sides of the passage 9, auxiliary springs 44a (see FIG. 17) for downwardly biasing the retainers 44, and the inclined surfaces 9a of the bottom wall surface of the passage 9. The pair elastic retainers 44 are formed to be integral with a synthetic resin portion as a front end portion of the playing unit 2. As shown in FIG. 17, each inclined surface 9a has a recess 45 (only left side one being shown) formed at a position corresponding to the free end of each elastic retainer 44 to increase the flexing extent thereof.

The pair elastic retainers 44 are held within the passage 9 of the disc D with their lower surfaces inclined relative to the plane of the disc D. When the disc D is inserted from the disc insertion slot 3, the elastic retainers 44 have their lower surfaces raised by the edge of the disc D, thus permitting the disc D to enter the space between them and the inclined surface portions 9a. When the disc D reaches a playing position, as shown in FIG. 3, it is spaced apart form the elastic retainers 44 and the inclined surfaces 9a.

As shown in FIG. 2, the elastic holding mechanism 43 serves to elastically hold a portion of the disc D on the outer side of the recording area lest the disc D so that the disc D does not get out from the disc insertion slot 3 to the outside when the disc D is pushed back by the transfer means 10 from the playing portion P toward the disc insertion slot 3.

In order that the disc D can be readily taken out with a hand, the extent of push-back of the disc D by the push-back member 12 is desirably set to be as great as possible. When the disc D is pushed back by the push-back member 12 to a position, at which the center hole of the disc D at least partly projects from the disc insertion hole 3, the disc D can be readily taken out by holding its portion on the inner side of the recording area from both the upper and lower sides with fingers. As shown in FIG. 2, with an arrangement that the disc D is pushed back up to a position, at which the center hole of the disc D fully projects from the disc insertion slot 3, the disc D can be readily taken out by inserting fingers into the center hole.

The disposing position of the elastic holding mechanism 43 is restricted. That is, the elastic holding mechanism 43 should be disposed at a position that the disc D can be held at the position thereof reached when pushed back by the transfer means 10, while being out of contact with the disc during playback and also out of contact with the recording area of the disc during the disc transfer. Referring to FIG. 18, shown coarsely shaded is passage of the recording area of the disc D, and the range of the disc that can be held is on the outside of the coarsely shaded area as finely shaded. Thus, with the elastic retainers 44 formed such that their lower surfaces are inclined relative to the plane of the disc D for holding the edge of the disc D pushed back by the transfer means, the scope be increased, thus increasing the degree of freedom of design. As shown in FIG. 2 to FIG. 7, a lower guide piece 46 is provided on the lower wall surface of the passage 9 of the disc D, and a left and a right upper guide pieces 47 are provided on the ceiling plate 2a between the disc insertion slot 3 and the turntable 5. The disc D inserted form the disc insertion slot 3 is thus led through the space between the lower guide piece 46 and the upper guide piece 47 to the space between the turntable 5 and the clamper 6.

As shown in FIGS. 4 and 5, the clamper supporting member 4 is mounted by a horizontal shaft 48 in the rearmost portion of the playing unit 2. The clamper 6 can be moved vertically by causing vertical rocking of the clamper supporting member 4. The clamper supporting member 4 has a cam contact portion 49 depending from its lower surface. As shown in FIG. 3, the cam contact portion 49 is always biased by a pair of springs 50 to be in contact with the top surface of the rotation member 17.

When the cam contact portion 49 is brought into contact with the clamper control cam 34 with rotation of the rotation member 17, the clamper supporting member 4 is caused to rock downward. As a result, the clamper 6 is lowered and comes to hold the disc D on the turntable 5. In this state, the turntable 5 can be rotated for playing back data with the pick-up 8.

As shown in FIG. 19, the turntable 5 has a center boss 51 having a center hole, in which the shaft of the motor 7 is fitted, an annular projection 52 formed around the boss 51, and a disc holding surface 53 formed on the outer periphery of the top surface. The boss 51 and the annular projection 52 do not project upward from the disc holding surface 53. Thus, the disc D can be transferred from the disc insertion slot 3 to the playing portion without being obstructed by the boss 51 or annular projection 52. That is, the disc D can be transferred horizontally at a level very close to the disc holding surface 53. After the disc D has been transferred to its set position on the turntable 5, it can be held on the disc supporting surface 53 by merely lowering the clamper 6.

The clamper 6 has a flange portion 54 for pushing the disc D on the disc holding surface 53 and an annular projection 55 for being fitted on the boss 51. The annular projection 55 has a circular small recess 56, in which the annular projection 52 is to be fitted. The turntable 5 and the clamper 6 are centered to each other by the engagement between the outer periphery of the boss 51 and the inner periphery of the annular projection 55. In addition, the turntable 5, the clamper 6 and the disc D are centered to one another by fitting the annular projection 55 in the center hole of the disc D.

As shown in FIG. 2, in a right side part of the playing unit 2 a stopper 57 is mounted on a shaft 58 for horizontal rocking thereabout. As shown in FIG. 20, the stopper 57 has a disc receiving portion 59 provided at one end, having a V-shaped form, and also an engagement pin 60 provided at the other end, and it is biased for rocking in the counterclockwise direction by a torsion spring 61. The stopper 57 has an upwardly projecting preventing portion 62 formed between the disc receiving portion 59 and the center of rocking. The preventing portion 62 terminates in a downwardly inclined surface, which serves as a sliding contact portion 63.

As shown in FIG. 5, the clamper supporting member 4 has a downwardly extending engagement portion 64 provided on one side. The engagement portion 64 is movable along a line of movement as the clamper supporting member 4 rocks. The stopper 57 is located beneath the engagement portion 64 so as to be selectively positioned on the line of movement of the engagement portion 64. The stopper 57 is normally at a position as shown in FIG. 2. In this state, the preventing portion 62 is located under the engagement portion 64 as shown in FIG. 21A and prohibiting downward rocking of the clamper supporting member 4. When the disc D is inserted and reaches the position to be held on the turntable 5, the disc receiving portion 59 is pushed by the edge of the disc D, thus causing rocking of the stopper 57 to an approach allowable position. As shown in FIG. 21B, the preventing portion 62 is caused to depart from its position under the engagement portion 64, and the sliding contact portion 63 replaces the preventing portion 62 and is brought to the position under the engagement portion 64, so that the clamper supporting member 4 becomes ready to rock downward. When the clamper supporting member 4 rocks downward, the engagement portion 64 is brought into contact with the sliding contact portion 63 and causes further clockwise rocking of the stopper 57, thus bringing the disc receiving portion 59 to a retreated position spaced apart from the edge of the disc D, as shown in FIG. 21C.

As shown in FIGS. 2 and 22, in the playing unit 2 at a position thereof near the disc insertion slot 3, a slide 65 is mounted for movement in transversal directions. The slide 65 has a rack 66 provided at the top surface, and is always pulled by a spring 67 toward a rightward direction. A double insertion prohibit member 68 is mounted through a shaft 69 between the slide 65 and the disc insertion slot 3. The member 68 had a gear portion 70 in mesh with the rack 66.

The double insertion prohibit member 68 is normally at a position spaced apart from the passage 9 of the disc D. When the slide 65 is moved to the right, the member 68 is caused to rock by substantially 90 degrees to an upright state at a front position of the passage 9 of the disc D, as shown in FIG. 23, and thus prohibits insertion of the disc D from the disc insertion slot 3. As shown in FIG. 2, the stopper 57 and the slide 65 are coupled to each other via an intermediate member 71. The intermediate member 71 is capable of rocking horizontally about a shaft 72, and has an end portion having an elongate hole 73, in which the engagement pin 60 of the stopper 57 is received, and has the other end rockably coupled to the slide 65. The engagement pin 60 is held at the right end of the elongate slot 73 by the elastic force of the spring 67.

In the disc player having the construction as described above, the disc D is transferred as follows.

Before the disc insertion, the push member 40 is holding the push-back member 12 at the position as shown in FIG. 8, with its first and second disc receiving portions 22a and 22b found above the turntable 5. In this state, the cam pin 24 of the connecting member 13 is located in the cam groove 23 in the end portion thereof remote form the center of rocking, and is holding the disc push portion 21 of the push-forth member 11 at the left end of the disc insertion slot 3. Also, as shown in FIG. 15A, the first switch 42a is held pushed and "on" by the pressure receiving portion 29 of the push-back member 12, and the second switch 42b is found in the first angular hole 36a of the rotation member 17 and "off". Furthermore, the one-direction motor 19 is held stationary.

In this state, the edge of disc D inserted from the disc insertion slot 3 passes by the disc pushing portion 21 of the push-forth member 11 and, as shown in FIG. 7, comes to intervene between the elastic retainers 44 and the inclined surface portions 9a.

As shown in FIG. 2, after the edge tip of the disc D has been brought into contact with the first disc receiving portion 22a of the push-back member 12, the disc D pushes forth the push-back member 12 (toward the rear of the playing unit 2). At this time, the push-back member 12 rocks to cause movement of the cam pin 24 of the connecting member 13 along the cam groove 23. The connecting member 13 and the push-forth member 11 thus follow the push-back member 12, and the disc push portion 21 of the push-forth member 11 is brought to be ready for pushing forth the edge of the disc D.

The rocking of the push-back member 12 eventually also brings the second disc receiving portion 22b of the push-back member 12 into contact with the edge of the disc D. Eventually, however, as shown in FIG. 11, the first disc receiving portion 22a is separated from the edge of the disc D, and the disc D consequently pushes the sole second disc receiving portion 22b.

As shown in FIG. 15C, when the push-back member 12 has rocked to the position shown in FIG. 11 and the contact portion 28 enters the orbit of rocking of the push portion 37, the first switch 42a is released from the pressure receiving portion 29 and turned off, whereupon the one-direction motor 19 (at position a in FIG. 24) is started.

The rotation member 17 receives the torque from the motor 19 thus started, and is rotated in the clockwise direction, thus pushing the contact portion 28 with the push portion 37 and causing counterclockwise rocking of the push-back member 12. The connecting member 13 and the push-forth member 11 follow the push-back member 12, and rock in the counterclockwise direction. The disc push portion 21 of the push-forth member 11 thus quickly pushes forth the disc D.

At this time, the connecting member 13 and the push-forth member 11 are held to be integral with each other merely elastically by the spring 14. Thus, the elastic force of the spring 14 neither affects the engagement relation between the cam groove 23 and the cam pin 24 nor constitutes any load on the one-direction motor 19. The push-back member 12, the connecting member 13 and the push-forth member 11 are thus smoothly moved.

Sometimes, the user may intend in fluster to pull out the disc D which is being brought forth by the driving force of the motor 19. In such a case, it is undesired if the disc can not be pulled out due to surpassing mechanical force or if the internal mechanism is damaged due to excessively strong pulling force.

In the disc player as described above, the push-forth member 11 and the connecting member 13 are held integrally by the spring 14. Thus, when the user intends to pull out the disc D being brought forth toward the playing portion P by the diving force of the motor 19, the push-forth member 11 is pushed by the edge of the disc D and, as shown in FIG. 25, rocks away from the connecting member 13 while elongating the spring 14. The disc D thus can be pulled out safely without possibility of damaging the internal mechanism.

Besides, since the stopper 57 prohibits the descent of the clamper 6 until the disc D has been set in the play position, it is not possible the clamper which may otherwise be lowered makes it difficult to take out the disc D being inserted.

Right after the start of the one-direction motor 14, the second switch 42b is detached from the first angular hole 36a, and is pushed and turned on by the bottom surface of the rotation member 17. At this time, the one-direction motor 19 continues its rotation. (at position b in FIG. 24) In the meantime, the push pin 40b of the push member 40 is shifted from the first pressure receiving surface 29b of the pressure receiving portion 29 to the second pressure receiving surface 29c thereof, and applies counterclockwise torque to the push-back member 12.

When the disc D comes to a position to be concentric with the turntable 5, as shown in FIG. 12, the push portion 37 of the rotation member 17 is separated from the contact portion 28 of the push-back member 12, and the first arcuate surface 38 is in turn brought into contact with the contact surface 28. At this time, the push-back member 12 suspends its rocking for a while. Also, the push pin 40b of the push member 40 is on the shoulder 29d of the pressure receiving member 13, and provides no torque to the push-back member 12. Furthermore, the cam pin 24 of the connecting member 13 is at a position in the cam groove 23 of the push-back member 12 near the end closer to the center of rocking.

When the disc D comes to a position to be capable of being held on the turntable 5, the edge of the disc D pushes the disc receiving portion 59 of the stopper 7. As a result, the preventing portion 62 of the stopper 57 departs from its position below the engagement portion 64, and this position is in turn assumed by the sliding contact portion 63. As shown in FIG. 26, the edge of the disc D is consequently held at three points by the disc push portion 21 of the push member 11, the second disc receiving portion 22b of the push-back member 12 and the disc receiving portion 59 of the stopper 57.

While the first arcuate surface 38 is in contact with the contact portion 38, the push-back member 12 is suspending its rocking. During this time, the rotation member 17 is still continually rotated. The cam contact portion of the clamper supporting member 4 is thus eventually brought into contact with the clamper control cam 34 of the rotation member 17. As a result, the clamper supporting member 4 is caused to rock down to lower the clamper 6. The clamper 6 thus comes to hold the disc D on the turntable 5 with its flange portion 54. During the downward rocking of the clamper supporting member 4, as shown in FIG. 21C, the engagement portion 64 slides on the sliding contact portion 63, thus causing movement of the stopper 57 to the retreated position to be out of contact with the edge of the disc D.

With further rotation of the one-direction motor 19, the contact point of the contact portion 28 is eventually shifted from the first arcuate portion 38 to the second arcuate portion 39. As a result, the push-back member 12 is caused to slightly rock again in the counterclockwise direction.

As shown in FIG. 13, the counterclockwise rocking of the push-back member 12 causes the cam pin 24 of the connecting member 13 to be moved to the separating portion of the cam groove 23, causing slight clockwise rocking of the push-forth member 11. As shown in FIG. 27, the disc push portion 21 of the push-forth member 11 and the disc receiving portion 22b of the push-back member 12, following the disc receiving portion 59 of the stopper 57, are separated from the edge of the disc D. While the cam pin 24 is moved along the cam groove 23, the elastic force of the spring 14 neither affects the engagement relation between the cam pin 24 and the cam groove 23 nor constitutes any load on the one-direction motor 19.

At the time of separation of the disc receiving portion 59 from the edge of the disc D with the downward rocking of the clamper supporting member 4, the stopper 59 is caused to rock, thus causing the engagement pin 60 to move along the elongate hole 73 in the intermediate member 71 and eventually come to push the other end of the elongate hole 73. As a result, the intermediate member 71 is caused to rock in the clockwise direction, thus causing rightward movement of the slide 65 against the force of the spring 67. As shown in FIG. 23, the double insertion prohibit member 68 is thus brought to its upright position.

When the second angular hole 36b of the rotation member 17 comes to the position of the second switch 42b, the second switch 42b is released from the rotation member 17 and turned off, thus stopping the one-direction motor 19 (at position c in FIG. 24).

Then, the motor 7 of the playing portion P is started to cause rotation of the turntable 5, the clamper 6 and the disc D in unison with one another, while the pick-up 8 is also operated. Data recorded in the disc D is thus played back.

There may occur a circumstance when the user intends by mistake to insert other disc during the above playback operation. In such a case, the other disc being inserted may be brought into contact with and damage the inner disc D under rotation or cause damage to the internal mechanism. In the disc player of the present invention as described herein, the double insertion prohibit member 68 is held upright on the passage 9 of the disc D and prohibits the insertion of other disc during the playback operation. It is thus possible to eliminate the possibility of doubly inserting a disc and causing damage to the disk and the internal mechanism due to otherwise possible double insertion.

When the operation of unloading the disc D is caused by stopping the playback operation, an ejection switch (not shown) is turned on to start the one-direction motor 19 (at position d in FIG. 24) again.

The re-start of the one-direction motor 19 causes the clamper control cam 34 to be separated downward from the cam contact portion 49. As a result, the clamper supporting member 4 is caused to rock upward and raise the clamper 6. At this time, the stopper 57 is released from the engagement portion 64 and restored to the initial position by the torsion spring 61, thus bringing its disc receiving portion 59 into contact with the edge of the disc D. Also, the slide 65 is restored by the spring 67, causing rocking of the double insertion prohibit member 68 to a position beneath the passage 9 of the disc D.

Right after the re-start of the one-direction motor 19, the second switch 42b is detached from the second angular hole 36 of and turned on by the rotation member 17. At this time, the motor 19 (at position e in FIG. 24) is continually rotated. In the meantime, the partial gear 31 of the rotation member 17 is brought into mesh with the idler gear 18. Since the idler gear 18 is normally in mesh with the gear portion 27 of the push-back member 12, the torque of the motor 19 is thus the gear portion 27 of the push-back member 12, thus causing clockwise rocking thereof and bringing the second disc receiving portion 22b into contact with the edge of the disc D. At the same time, the cam pin 24 of the connecting member 13 leaves the separating portion 23a and causes slight counterclockwise rocking of the push-forth member 11, thus also bringing the disc push portion 21 of the push-forth member 11 into contact with the edge of the disc D.

As the clockwise rocking of the push-forth member 11 proceeds in this state, as shown in FIG. 28, the disc D is pushed back from the playing portion P toward the disc insertion slot 3 by the second disc receiving portion 22b and subsequently by the first disc receiving portion 22a replacing the second one. In this operation, the disc is transferred relatively slowly compared to the speed in the disc loading operation although the rotation speed of the motor 19 is constant. This is so because in the disc unloading operation the disc is transferred via the train of the partial gear 31, the idler gear 18 and the gear portion 27 meshed with one another, while in the disc loading operation it is transferred with the contact portion 28 of the push-back member 12 pushed by the push portion 37 of the rotation member 17.

When the pressure receiving portion 29 of the push-back member 12 comes to the position above the first switch 42a again, the switch 42a is turned on (at position f in FIG. 24).

When the disc D has been pushed back by the first disc receiving portion 22a of the push-back member 12 up to a position with its center hole fully exposed on the outside of the disc insertion slot 3, the cam pin 24 of the connecting member 13 is caused to move along the cam groove 23 from a position thereof close to the rocking center to a position near the end remote from the rocking center. As a result, the disc push portion 21 of the push-forth member 11 is restored to a position in the neighborhood of the left end of the disc insertion slot 3.

Also, the first angular hole 36a of the rotation member 12a comes again to be above and turns on the second switch 42b, thus stopping the one-direction motor 19 (at position g in FIG. 24).

The edge of the disc D is pushed back by the push-back member 12 while being elastically held between the elastic retainers 44 and the inclined surface portions 9a, so that it does not get out or down from the disc player although it is brought to a position that more than one half of it projects from the disc player to the outside. The disc D at this position can be readily taken out by inserting fingers into its center hole.

In the above embodiment, the sliding contact portion 63 having a downwardly inclined surface is provided on the stopper 57 for being in sliding contact with the engagement portion 64 of the clamper supporting member 4 to separate the stopper 57 from the disc D. However, the same effects are obtainable by providing the sliding contact portion on the side of the engagement portion 64 for being in contact with the stopper 57 to separate the same from the disc D. The sliding contact portion may not have the inclined surface, for instance, it may have an arcuately convex shape.

As has been described in the foregoing, the disc loading apparatus according to the invention has the clamper supporting member 4, which carries the clamper 6 and has the engagement portion 64, and the stopper 57 located underneath the engagement portion 64 movable along the line of movement. The stopper 57 is normally at its preventing position of being in contact with the engagement portion 64 to prevent the clamper 6 from approaching the turntable 5 and, when the disc D has been inserted up to a position that the disc D can be held on the turntable 5, it is pushed by the disc D and moved to the approach allowable position to allow the clamper 6 to approach the turntable 5. When the clamper 6 approaches the turntable 5, the stopper 57 is pushed by the engagement portion 64 of the clamper supporting member 4 to the retreat position, at which the stopper is out of contact with the disc D.

With this construction, the disc D being inserted can be pulled out without possibility of causing damage to the disc D or the internal mechanism, because in this case the stopper 57 prevents the clamper 6 from approaching the turntable 5. When the disc D is normally inserted, it pushes the stopper 57 to the approach allowable position. Thus, the provision of the stopper 57 has no adverse effects on the operation of the clamper 6. Besides, since the stopper 57 is separated from the disc D by the engagement portion 64 while the clamper 6 approaches the turntable 5, the disc D can be turned without possibility of being obstructed by the stopper 57.

With the arrangement that the stopper 57 is separated from the disc D with sliding of the engagement portion 64 along the sliding contact portion 63 provided on the stopper 57, the stopper 57 can be separated from the disc D with a simple construction. The same effects are also obtainable with a converse arrangement that the sliding contact portion is provided on the engagement portion 64 and caused to slide along the stopper 57.

Furthermore, the double insertion prohibiting member 68 is provided such that it is interlocked to the stopper 57 such as to appear on the passage 9 of the disc D from a different position from the position of the passage when the stopper 57 is moved to the playback preparation completion position by the engagement portion 64 of the clamper supporting member 4 pushing the stopper. It is thus possible to reliably prohibit the double insertion, i.e., insertion of other disc by mistake during playback, with a simple construction.

## Claims

1. A disc loading apparatus for a disc player in which a clamper can be moved toward a turntable to hold the disc on the turntable, said disc loading apparatus comprising: engagement portion: stopper is in contact with said engagement portion to prevent said clamper from approaching said turntable; ready to be held on said turntable, by being pushed by the edge of said disc to an approach allowable position, which allows said clamper to approach said turntable; turntable, by being pushed by said engagement portion, from said approach allowable position to a retreated position, which is out of contact with said disc on said turntable; and movement of said engagement portion when it is held at said preventing position, and a sliding contact portion located in said line of movement of said engagement portion when it is positioned at said approach allowable position, said engagement portion being brought, when said clamper supporting member approaches said turntable, into sliding contact with said sliding contact portion, thereby causing said stopper to be moved from said approach allowable position to said retreated position.

2. The disc loading apparatus for a disc player according to claim 1, further comprising a double insertion prohibit member interlocked with said stopper such as to move, with the movement of said stopper from said approach allowable position to said retreated position, in the passage of said disc, thereby prohibiting the insertion of said disc.

3. A disc loading apparatus for a disc player in which a clamper can be moved toward a turntable to hold the disc on the turntable, said disc loading apparatus comprising: engagement portion; stopper is in contact with said engagement portion to prevent said clamper from approaching said turntable; ready to be held on said turntable, by being Pushed by the edge of said disc to an approach allowable position, which allows said clamper to approach said turntable; turntable, by being pushed by said engagement portion, from said approach allowable position to a retreated position, which is out of contact with said disc on said turntable; and stopper is located in a line of movement of said sliding contact portion when said stopper is positioned at said approach allowable position, and when said clamper supporting member approaches said turntable, said sliding contact portion is brought into contact with said stopper, thereby causing said stopper to be moved from said approach allowable position to said retreated position.

4. The disc loading apparatus for a disc player according to claim 3, further comprising a double insertion prohibit member interlocked with said stopper such as to move, with the movement of said stopper from said approach allowable position to said retreated position, in the passage of said disc, thereby prohibiting the insertion of said disc.