Disc player for player discs disposed in cassettes defining a window opening and closeable by a sliding element

A combination includes a plurality of disc assemblies, each having: a disc; a cassette having a window and a sliding element adapted to open and close the window, the disc being disposed in the cassette so as to be accessible by a playback unit of a disc player through the window. The combination further includes a disc player having: a playback unit; a disk magazine including a plurality of disc compartments disposed to form a stack, each of the compartments being adapted to receive a corresponding one of the disc assemblies therein; a transport device travelling toward and away from the stack for transferring a pre-selected disc assembly between a corresponding receiving compartment and the playback unit; and a plurality of cassette holders, each holding a corresponding one of the disc assemblies therein and further being adapted to be gripped by the transport device for being transferred between a receiving compartment and the playback unit. Each of the cassette holders further have: a frame; a catch fixed to the frame for moving the sliding element of the cassette into an open position when the corresponding one of the disc assemblies is inserted into the cassette holder; and an elastic projection distinct from the catch fixed to the frame for moving the sliding element into a closed position when the corresponding one of the disc assemblies is removed from the cassette holder.

FIELD OF THE INVENTION 
The invention relates to a disc player having at least one disc magazine 
which contains a plurality of discs lying in receiving compartments one on 
top of the other, and further having a transport device which can travel 
in the direction of the stack of the disc magazine for transferring a 
desired disc between the receiving compartment and a playback unit. 
BACKGROUND OF THE INVENTION 
Disc players of the above type are known in a wide variety of embodiments. 
For example, EP 0 439 483 B1 shows a disc player having two disc magazines 
which are located opposite each other and include a plurality of disc 
holders which are seated in receiving compartments one above the other and 
each receive one disc, the device further including a transport device 
which can be moved in the direction of the stack of the disc magazines for 
conveying a disc, with the associated disc holder, back and forth between 
the disc magazines and a playback unit. The discs are therefore first 
placed into the disc holders, and the disc holders respectively occupied 
by a disc are subsequently inserted into the receiving compartments of the 
disc magazines. Usually, so-called CDs (compact discs) are involved, which 
have a long playing time, but nevertheless a small diameter of up to 8 cm, 
which permits the use of a playback unit and disc magazines of compact 
construction, so that the disc playback device has a relatively small 
overall size. 
Moreover, in the interim a disc player has become known which plays a disc 
while it is held in a flat cassette serving to protect it. The cassette is 
provided on one hand with an access opening, through which the disc is 
gripped by the playback unit and rotated, and on the other hand with a 
window, through which the disc can be scanned while it rotates in the 
cassette by the playback head of the playback unit. In the unused state of 
the cassette, the window is closed by a sliding element integrated into 
the cassette, and is opened by a suitable mechanism when the cassette is 
inserted into the disc player and closed again when the cassette is 
withdrawn after the disc has been played. The discs accommodated in the 
protective cassettes are typically so-called mini-compact discs, which 
have an extremely long playing time but nevertheless a small diameter of 
up to 6 cm. The type of discs which are received in protective cassettes 
cannot be played in the disc players known up to now that include a large 
number of disc magazines which receive discs, particularly because these 
disc players do not possess any of the complex mechanisms disposed 
upstream of the playback unit for the purpose of operating the sliding 
element of the cassette. 
SUMMARY OF THE INVENTION 
The object of the invention is to create a disc player of the type 
mentioned at the outset with which discs received in flat protective 
cassettes can be played without a large structural outlay. 
In accordance with the invention, this object is accomplished in that 
--each disc is accommodated so as to rotate in a manner known per se in a 
cassette having at least one window which is associated with the playback 
head of the playback unit and can be closed by a sliding element, 
--each cassette is inserted into a cassette holder which is seated in the 
receiving compartment of the disc magazine and can be gripped by the 
transport device, and 
--each cassette holder is provided on the one hand with a catch which 
transfers the sliding element into the open position when the cassette is 
inserted into the cassette holder, and on the other hand with an elastic 
projection which transfers the sliding element into the closed position 
when the cassette is withdrawn from the cassette holder. 
The result of these measures is a structurally simple and compact disc 
player which permits the playback of discs accommodated in special 
cassettes. The cassette holder assures, on the one hand, a narrow stack 
spacing of the cassette holders with respect to each other and, on the 
other hand, reliable opening and closing of the sliding element. In the 
working position of the cassette, that is, in the state of the cassette 
being inserted into the cassette holder, the window of the cassette is 
kept open, making the disc available for playback, while in the 
non-working state of the cassette, that is, when the cassette is removed 
from the cassette holder, the window of the cassette is closed, protecting 
the disc completely protected against the effects of dirt. 
In an advantageous embodiment of the invention, the sliding element of the 
cassette is fixed in the closed position by a spring-loaded locking 
device, and the catch of the cassette holder does not release the locking 
device until the cassette is inserted into the cassette holder. In this 
way, a sliding element of the cassette which is locked in the closed 
position is reliably released from its locked position when the cassette 
is inserted into the cassette holder. 
To assure secure holding of the cassette in the cassette holder, in 
accordance with a preferred modification of the invention, the cassette 
holder, which encompasses a frame, has at least two holding ribs located 
opposite one another in the rear region, when seen in the direction of 
insertion of the cassette, which extend into corresponding lateral slots 
of the cassette. 
Furthermore, it is preferably provided that the catch is formed on the 
inside of the side wall of the frame facing the window of the cassette 
and, when the cassette is inserted into the cassette holder, extends into 
the corresponding lateral slot of the cassette, pushes down a 
spring-loaded lever of the locking device, which lever protrudes into this 
slot, and comes to rest bent segment of the sliding element located in the 
closed position, which bent segment partly covers the slot. As a result, 
the window of the cassette can always be opened without problems. 
For the implementation of a reliable closing process of the window of the 
cassette, in accordance with a further advantageous embodiment of the 
invention, the elastic projection disposed on the inside of the side wall 
of the frame facing the window of the cassette extends into an associated 
opening of the bent segment of the sliding element in the state of the 
cassette being inserted into the cassette holder. When the cassette is 
pushed out of the cassette holder, the projection carries the sliding 
element along until the sliding element has assumed its closed position, 
and the projection subsequently moves out of the opening of the sliding 
element. The projection is purposefully formed on a resilient tongue swung 
out of the side wall of the frame. This is simple to execute with respect 
to production technology. In an alternative embodiment, the projection is 
configured as a spring-loaded latching pin inserted into the side wall of 
the frame. 
So that an information image applied to the associated cassette can be 
viewed in the correct, or readable, orientation during playback of a disc, 
in accordance with a further modification of the subject of the invention, 
the frame of the cassette holder is provided with a cover wall, into which 
a recess is cut that corresponds to the size of an information image that 
is applied to the top side of the cassette and is to be viewed in the 
correct position during playback of the disc located in the cassette. 
For secure seating and shifting of the cassette holder, the frame of the 
cassette holder preferably has two sliding rails located opposite each 
other on the outside, transversely to the direction of insertion of the 
cassette, for support in the receiving compartment of the disc magazine 
and in the carrier arm of the transport device. 
So that, in the case of two oppositely-located disc magazines, the cassette 
holder can be gripped in a simple manner by the transport device, a 
gripping pocket for a gripper arm of the transport device preferably 
adjoins the end of the front sliding rail of the frame, seen in the 
direction of insertion of the cassette. When the cassette is inserted in 
the cassette holder, the front sliding rail purposefully extends beyond 
the outer wall of the cassette facing the sliding rail at a specific 
height. This reduces a sliding of the cassette back out of the cassette 
holder, with the front sliding rail serving as a latch for the cassette. 
In order to achieve exact positioning of the cassette holder in the disc 
magazine and in the transport device, in a modification of the invention, 
a detent notch into which a detent spring of the disc magazine or a detent 
spring of the carrier arm of the transport device extends is cut into the 
center of the rear sliding rail of the frame when seen in the direction of 
insertion of the cassette in the cassette holder. 
Of course, the features cited above and those explained below can be used 
not only in the described combination, but also in other combinations or 
by themselves, without leaving the scope of the present invention.

DETAILED DESCRIPTION OF THE INVENTION 
As seen in FIG. 1, the disc player equipped with a central control unit, 
not shown, with which disc player information stored on the discs 1 can be 
read out and played back, includes a housing 2 having an associated 
operating panel, not shown, which has different keys, for example, a disc 
selection key, a disc playback key and a stop key. Disc magazines 3 
located opposite each other are disposed laterally in the housing 2. 
Disposed in the space between the disc magazines 3 is a transport device 4 
which can travel up and down and has a carrier arm 5 for a cassette holder 
6, into which a cassette 7 which rotatably receives a disc 1 is inserted 
(FIG. 2). A playback unit 38 having a turntable, not shown in detail, a 
motor for rotating the turntable, and a playback head, is fixedly disposed 
between and beneath the two disc magazines 3 located opposite each other. 
The disc magazines 3 are of identical construction, and respectively 
include a plurality of receiving compartments 8 disposed one above the 
other for storage of a corresponding number of cassette holders 6, each of 
which receives a corresponding disc assembly including cassette 7 with a 
disc 1 lying therein it. The cassette holder 6 is secured in its position 
in the receiving compartment 8 by at least one detent spring disposed on 
the disc magazine 3. In this position the cassette holder 6 protrudes so 
far beyond the two sides of the disc magazine 3 from which withdrawal is 
possible that it can be gripped by a gripper arm 52 of a withdrawal device 
44 of the transport device 4 (see FIGS. 6a and 6b). Each disc magazine 3 
is inserted into the housing 2 in drawer fashion so as to be exchangeable 
from the front side of the housing 2. The housing 2 comprises a 
rectangular floor plate 9 and a rectangular cover plate 10, which is at a 
specific distance from the floor plate; these plates can be connected to 
one another by connecting elements 11 configured as rods and disposed at 
the corners. The cover plate 10 is removable, and the connecting elements 
11 are exchangeable in length, so that disc magazines 3 of different 
heights can be used. Located opposite each other on the inside of the 
floor plate 9 and the inside of the cover plate 10 are guide rails 12 for 
each disc magazine 3 which correspond to a groove in the wall of the floor 
or in the wall of the cover of the disc magazine 3. 
As seen in FIGS. 2 and 3a, rectangular cassette 7 shown in a partially 
cut-away bottom plan view is closed on all sides and serves to protect the 
freely-movable disc 1 lying inside it. Cassette 7 is provided on its 
underside with a central access opening 13, through which the disc 1 can 
be set into rotation by the turntable of the playback unit 38. A window 14 
is located next to the access opening 13 in the underside of the cassette 
7; the disc 1 can be scanned through this window by the playback head of 
the playback unit 38 as it is rotated in the cassette 7. Associated with 
the window 14 is a sliding element 15 which is integrated into the 
cassette 7 and by means of which the window 14 can be opened and closed. 
The sliding element has a bent segment 24 which extends into a first 
lateral slot 16 of the cassette 7 and cooperates with a locking device 17, 
shown in a partially cut-away view of the cassette and not in detail, 
which has a spring-loaded lever 18 that dips into the slot 16 of the 
cassette 7. To open the window 14, first the locking device 17 must be 
released; only then can the sliding element be moved into its open 
position. Located opposite the slot 16 in the one side wall of the 
cassette 7 is a second lateral slot 19 in the other side wall. 
As seen in FIG. 3b, the cassette holder 6 encompasses a frame 20 that 
receives the cassette 7 and on whose side wall 21 facing the window of the 
cassette 7 a catch 22 which extends into the slot 16 of the cassette 7 is 
formed in a position in which it first releases the locking device 17 for 
the sliding element 15 when the cassette 7 is inserted into the cassette 
holder 6 from the front side 23 of the cassette holder 6, and then, by 
virtue of the insertion of the cassette toward the back side 30 moves the 
sliding element 15 into the open position by means of contact with the 
bent segment 24 of the sliding element 15. In the open position of the 
sliding element 15, an elastic projection 25 disposed at an inside region 
of the side wall 21 of the frame 20 latches into an associated opening 26 
of the bent segment 24 of the sliding element 15, and thus holds the 
sliding element 15 fixedly in its open position. When the cassette 7 is 
pushed out of the cassette holder 6 in the direction of the front side 23 
of the cassette holder 6, the sliding element 15 is transported by the 
projection 25 into the closed position, in which it is fixed by the 
locking device 17, and the projection 25 subsequently slides out of the 
opening 26. The projection 25 is formed on a resilient tongue 27 adapted 
to swing in and out of the side wall 21 of the frame 20. 
A holding rib 28 formed on the side wall 21 and extending into the slot 16 
of the cassette 7 extends in front of the catch 22 of the side wall 21 of 
the frame 20. Two further holding ribs 28, which are spaced from each 
other and extend into the slot 19 of the cassette 7, are formed on the 
side wall 29 of the frame 20 located opposite the side wall 21. Located on 
both the front side 23 and the rear side 30 of the frame 20 is a sliding 
rail 31, which serves as a support in the receiving compartment 8 of the 
disc magazines 3 and in the carrier arm 5 of the transport device 4. 
Adjoining the end of the front sliding rail 31 when seen in the direction 
of insertion of the cassette 7 in the cassette holder 6 is a gripping 
pocket 32, into which a gripper arm of a withdrawal device of the 
transport device 4 can extend in order to convey the cassette holder 6. In 
the state of the cassette 7 being inserted into the cassette holder 6, at 
a specific height the front sliding rail 31 extends beyond the outside 
wall of the cassette 7 facing the sliding rail 31. The rear sliding rail 
31 when seen in the direction of insertion of the cassette 7 into the 
cassette holder 6 is provided in the center with a detent notch 33. In the 
end position of the cassette holder 6 in the disc magazine 3, a detent 
spring correspondingly fixed on the disc magazine extends into the detent 
notch 33. Likewise, a detent spring 54 fixed on the carrier arm 5 extends 
into the detent notch 33 in the end position of the cassette holder 6 in 
the carrier arm 5 of the transport device 4. As seen in FIGS. 4a and 4b, 
frame 20 of the cassette holder 6 is provided with a cover wall 34, into 
which a recess 35 is cut which corresponds to the size of an information 
image 36 applied to the top side of the cassette 7. Moreover, an arrow 37 
which indicates the direction of insertion of the cassette 7 into the 
cassette holder 6 is located on the top side of the cassette 7. The 
information image 36 of the cassette 7 can therefore be viewed in the 
correct position during playback of the disc 1 contained in the cassette 
7. 
FIG. 5 shows a perspective view of a conventional playback unit 38 which 
may be used in the disc player of FIG. 1. The playback unit 38 includes a 
playback head 40 and a rotating turntable 42. 
FIG. 6a shows a perspective view of conventional features of a transport 
device 4 which may be used in the disc player of FIG. 1. The transport 
device includes the carrier arm 5 and a withdrawal device 44 which 
includes a bottom portion 46 and a belt drive 48. 
FIG. 6b is a top view of a rear portion of the transport device of FIG. 6a 
equipped with gripper arms shown in schematic form. As seen in FIG. 6b, 
bottom portion 46 includes a conventional actuation control mechanism 50 
for actuating gripper arms 52 shown in schematic form. As seen in FIG. 6b, 
gripper arms 52 can engage gripping pockets 32 of cassette holder 6 for 
holding the cassette holder on the transport device as previously 
described. 
FIG. 6c is a top view of detent notch 33 of cassette holder 6 into which a 
detent spring 52 (shown in schematic form) of either disc magazine 3 or 
carrier arm 5 extends by means of a conventional actuation control 
mechanism 56. 
FIG. 7a is a side elevational view of the cassette of FIG. 3a seen in the 
direction of arrow A, and shows the lateral slot 16 of the cassette 7. 
Bent segment of 24 of sliding element 15 extends into slot 16 and includes 
the opening 26 therein as shown. 
FIG. 7b is a side elevational view of the cassette of FIG. 3a seen in the 
direction of arrow B, and shows the slot 19 therein. 
FIG. 8a shows a detail of side wall 21 including the resilient portion 27 
which swings in and out of the plane of the side wall 21 as shown by arrow 
"C", and which has the elastic tongue 25 thereon. FIG. 8a further shows 
both the catch 22 and holding rib 28 adapted to extend into slot 16. 
FIG. 8b shows a detail of side wall 29 including holding ribs 28 also 
adapted to extend into slot 16. 
It is noted that at least FIGS. 7a, 7b, 8a and 8b are not necessarily to 
scale.