KR19990075298A - Disc storage cartridge having disc recognition device - Google Patents

Abstract

The present invention relates to a disc housing cartridge having a disc recognition device, comprising a cartridge having accommodation holes on its upper and lower surfaces so that a disc can be accommodated, and a shutter for opening and closing the accommodation hole is mounted on the cartridge front side. The cover which prevents the disc from coming off is hinged, and the cover is provided with a rotary arm for checking the state of the disc and a lock rib for locking and / or releasing the disc, thereby confirming the operation according to the state of the disc exchanged and received in the cartridge. When the disc is stored in the cartridge case, the recording and reproducing apparatus can recognize the state of the disc, thereby reducing the recording time.

Description

Disc storage cartridge having disc recognition device

The present invention relates to a disc housing cartridge having a disc recognizing device, and more particularly, a disc recognizing device for adjusting a recognizing device for checking the state of a disc according to a disc housed in a cartridge case to shorten a recording time. A disk storage cartridge having a device.

In general, the cartridge is to prevent dust, fingerprints, or scratches on the surface of the disc for DVD-RAM having a diameter of 12 cm stored therein to record desired information without errors and to protect the recorded information. As shown in Fig. 1, the cartridge of the cartridge comprises a cartridge case 2 in which a disk D having a diameter of 12 cm is accommodated by molding a synthetic resin or the like and a shutter 4 mounted on the front side thereof.

The cartridge case 2 is composed of an upper case 6 having a size of 137.5x124.5 mm and a lower case 8 coupled thereto. The upper and lower cases 6 and 8 are provided with seating and chucking disks. To the turntable (ø28 to 30 mm) constituting the recording and reproducing apparatus and the accommodating holes 6a and 8a having a diameter of 34 mm to enter the chucking clamper, and the opening hole 6b which serves as a transfer path of the optical pickup apparatus. ) 8b are formed respectively.

The cartridge case 2 is formed with a pair of positioning pin holes 2a, a plurality of recognition holes 2b, 2c, 2d and long holes 2f positioned diagonally. The long hole 2f is formed at a position corresponding to the protector hole 2e.

Recognition holes (2b) (2c) and (2d) are holes (A1) (2b) for checking whether the disc is replaced or not for the cartridge case (2), holes (A2) (2c) for checking the single side or both sides of the disc, and Preliminary holes A3 and 2d provided for additional functions, and protector holes 2e for preventing information from being recorded on the disc.

Here, among the recognition holes, the A1 hole 2b is shipped in the closed state for the first time, and is opened when the disc is taken out. The A2 hole 2c is deleted when the disc housed in the cartridge case 2 cannot be replaced, when the disc has a cross section, and when the disc case 2 can be replaced.

On the rear side of the cartridge case 2, the cover 10 is hinged so that the disc can be taken out or accommodated with respect to the cartridge case 2. The cover 10 has a lock lever 12 fitted into the lock hole 2g formed in the cartridge case 2 and a protector arm 14 inserted into the protector hole 2e and a locking rib caught by the protector arm 14 ( 16) is injection molded integrally.

Between the lock lever 12 and the protector arm 14, a plurality of through holes 2b ', 2c' and 2e correspond to the positions of the positioning pin holes 2a and the recognition holes 2b, 2c and 2e. ') Is formed.

The conventional cartridge configured as described above opens a hinged cover 10 for recording and / or reproducing information on the disc, and then stores the 12 cm disc in the cartridge case 2.

That is, the lock lever 12 formed on the cover 10 is pressed to release it from the lock hole 2g of the cartridge case 2, and then the disc is stored while the cover 10 is pulled out.

Then, when the cartridge case is seated on the tray, for example, a seating member which is taken out and retracted from the recording / reproducing apparatus, and then retracted, the shutter 4 mounted on the cartridge case 2 is a shutter opening and closing means (not shown). Is moved in one direction to open the accommodation holes 6a, 8a and the opening holes 6b, 8b.

At this time, as the deck base (not shown) of the recording / playback apparatus is raised at a predetermined angle, the turntable and the chucking clamper provided on the deck base enter the accommodation holes 6a and 8a to seat and chuck the disk.

Then, an unshown positioning pin provided on the deck base is inserted into the positioning pin hole 2a to determine the position of the cartridge case 2 with respect to the recording / playback apparatus, and the switch terminals are provided with recognition holes 2b and 2c ( 2e) and the through-holes 2b ', 2c', and 2e 'formed at positions corresponding thereto, respectively, to recognize the state of the disc.

For example, if the switch terminal is not inserted into the A1 hole (2b), it is recognized as a disc in the shipped state. If it is inserted, the switch terminal is recognized as the ejected state of the disc. If it is recognized and not inserted, it is recognized as a disk having a single-sided recording surface.

When the switch terminal is inserted into the protector hole 2e, it is recognized as a state for preventing the recording or erasing on the disc accommodated in the cartridge case 2.

However, in the above disc recognizing apparatus, when the cartridge containing the disc is inserted into the recording / reproducing apparatus, the state of the disc is unconditionally checked by the recording / reproducing apparatus irrespective of the state of the disc by the switch terminal inserted into the A1 hole. As a result, even when the disc is stored in the cartridge case, the disc recording time is delayed as the operation of checking the disc state is executed.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to carry out a check operation according to the state of a disc that is exchanged and stored in a cartridge case, thereby recording and reproducing at the time of storing a single disc whose state of the disc is confirmed. An apparatus for storing a disc having a disc recognition device capable of recognizing a state of a disc in a device and shortening a recording time is provided.

1 is a perspective view showing a cartridge in which a conventional 12 cm disc is accommodated;

2 is a plan view of a state in which the disc is accommodated in the cartridge shown in FIG.

3 is an exploded perspective view showing a disc storage cartridge having a disc recognition device according to the present invention;

4 is a perspective view of the combination of the disk storage cartridge shown in FIG.

5A, 5B, 5C, and 5D are enlarged views illustrating main parts of an operation state of the disc recognizing apparatus according to the present invention;

6 is a cross-sectional view taken along line A-A of FIG. 5B, showing a disc recognition device and a switch;

7 is a perspective view showing another embodiment of the disc recognizing apparatus in the disc storage cartridge according to the present invention;

8A, 8B, 8C, 8D, and 8E are operation diagrams of the disc recognition device shown in FIG. 7,

FIG. 9 is a sectional view taken along line B-B in FIG. 8C, illustrating a disc recognition device and a switch; FIG.

10 is a perspective view showing another embodiment of the disc recognition device according to the present invention;

11A is an operation diagram of the disc recognition device shown in FIG. 10;

FIG. 11B is a cross-sectional view taken along line C-C of the disc recognition device shown in FIG. 11A.

Explanation of symbols on the main parts of the drawings

20: cartridge case 20a: positioning pin hole

20b, 20c, 20d: Recognition hole 20b ', 20c', 20d ': Through hole

20e: Protector hole 20f, 20g: 1st and 2nd hole

20h: Lock hole 22, 24: Upper and lower cases

22a: boss 24a: fitting

22b, 24b: receiving hole 22c, 24c: opening hole

30: shutter 40,70,110: cover

42,72,112: Lock lever 42a, 128: Contact protrusion

44: protector arm 46: jamming rib

48: open rib 50,74,116: rotary arm

50a, 50b: first and second protrusions 52,76,114: tension ribs

54,90: lock rib 54a, 90a: latch portion

56: transfer rib 60: deck base

62: switch terminal 78,120: lock projection

80,120: Extended rib 100: Secondary rib

102: return protrusion 104: inclined rib

120a: taper portion 122: lock portion

124: variable rib 126: lock holder

126a: opening

Features of the present invention for achieving the above object, the cartridge having a receiving hole on the upper and lower surfaces so that the disk is accommodated; A shutter mounted to the front side of the cartridge to open and close the accommodation hole; A cover coupled to the cartridge to prevent separation of the disk; It is achieved by being provided in the cover and composed of disk recognition means for checking the state of the disk.

The cartridge according to the present invention is achieved by having a cartridge case consisting of a plurality of recognition holes located in a diagonal direction behind each other and an upper and lower case in which first and second holes are formed.

The disc recognition means according to the present invention is achieved by being provided with a rotary arm for opening and closing the recognition hole and a lock rib for locking and releasing the rotary arm while moving along the first long hole.

The disc recognition means according to the present invention is achieved by being provided with a lock portion for locking and releasing the rotary arm.

Best Modes for Carrying Out the Invention Preferred embodiments of a disc storage cartridge having a disc recognition device according to the present invention will be described in detail with reference to the accompanying drawings.

3 and 4 illustrate a first embodiment of a disc housing cartridge according to the present invention, wherein the cartridge is a cartridge case 20 in which the disc D is accommodated and a shutter 30 mounted on the front side thereof. Then, the cover 40 is hinged to the rear side of the cartridge case 20 and the cover 40 is provided with a disk recognition means for checking the state of the disk.

The cartridge case 20 is formed by coupling the upper case 22 having a plurality of bosses 22a protruding from the inner case of the cartridge case 20 and a lower case 24 having fitting protrusions 24a to be fitted to the boss 22a. The upper and lower cases 22 and 24 are provided with accommodation holes 22b and 24b into which the turntable and the chucking clamper enter, and opening holes 22c and 24c serving as transfer paths of the optical pickup device.

In the cartridge case 20, a positioning pin hole 20a is formed to insert the positioning pin 62 protruding from the deck base 60. The rear of the cartridge case 20 is positioned diagonally to each other to check the state of the disk. A plurality of recognition holes 20b, 20c, 20d and 20e and first and second long holes 20f and 20g are formed.

Recognition holes include an A1 hole 20b for checking whether the disc first contained in the cartridge case 20 is replaced, an A2 hole 20c for confirming whether the disc is single-sided or double-sided, and an A3 spare hole for checking the state of the disc. 20d) and a protector hole 20e for recording or erasing information on the disc.

Here, the first and second long holes 20f and 20g are formed at positions corresponding to the A3 reserve holes 20d and the protector holes 20e, and the first and second long holes 20f and 20g are fixed. It becomes an elliptical shape with a radius of curvature.

The cover 40 has a protector arm having one end inserted into the lock lever 42 and the protector hole 20e in which the contact protrusion 42a protrudes to the inner surface thereof so as to be inserted into the lock hole 20h formed in the cartridge case 20. The locking rib 46 on which the 44 and the protector arm 44 are integrally injection molded, and the through holes 20b ', 20c', 20d 'and 20e' are positioned at positions corresponding to the recognition holes. Is formed.

Reference numeral 48 is an open rib for finely opening the cover 40 with respect to the cartridge case 20 when the lock lever 42 is pressed.

The disc recognizing means inserts the switch terminal 62 into the through hole 20d 'and the A3 spare hole 20d according to the state of the disc accommodated in the cartridge case 20 or prevents the switch terminal 62 from being inserted. It consists of a rotary arm 50 for operating the lock arm 54 and the locking and releasing it during operation of the rotary arm 50.

The rotary arm 50 is integrally formed with a tension rib 52 so that the rotary arm 50 can be returned to its initial position when the cover 40 is opened with respect to the cartridge case 20. On the outer circumferential surface, the first protrusion 50a in contact with the contact protrusion 42a and the second protrusion 50b spaced at an obtuse angle and locked to the lock rib 54 protrude.

At one end of the lock rib 52, a latch portion 54a for locking and releasing the second protrusion 50b is bent, and the lock lever 42 and the lock rib 54 are operated when the lock lever 42 is operated. In order to transfer the generated pressing force to the lock ribs 54, one end of the transfer ribs 56 having a semicircular shape at the center thereof is connected to each other.

The operation of the disc storage cartridge according to the present invention configured as described above will be described in detail with reference to FIGS. 5A to 5D and FIG. 6.

When the cover 40 is closed after storing the disk in the cartridge case 20 to record and / or reproduce the information on the disk, the lock lever 42 injection-molded in the cover 40 is locked as shown in FIG. 5A. It is possible to prevent the disk from being detached from the cartridge case 20 in accordance with the jammed in 20h.

At this time, among the recognition holes 20b, 20c, and 20d formed in the cartridge case 20, the A3 spare hole 20d and the protector hole 20e are blocked by the rotation arm 50 and the protector arm 44. Insertion of the switch terminal 62 is prevented, and another switch terminal is inserted into the A2 hole 20c and the through hole 20c '.

Here, the disc housed in the cartridge case 20 is in a state of being shipped for the first time, and the A1 hole 20b is in a closed state.

In other words, when the cartridge case 20 is inserted into the recording / playback apparatus, the A3 spare hole 20d is irrespective of whether the switch terminal 62 attached on the deck base 60 is inserted into the A1 hole 20b. If not inserted into the recording / playback apparatus, the recording / playback apparatus checks the state of the disk.

In this way, the function of checking the state of the disk depending on whether the A3 reserve hole 20d is opened or closed is designed by the microcomputer and can be given a role thereof.

In the embodiments of the present invention, the description of the protector hole 20e for preventing rewriting or erasing of information on the disc is omitted.

On the other hand, when replacing the disc accommodated in the cartridge case 20 with a single disc whose state of the disc is checked, when the rotary arm 50 is pulled forward using a ballpoint pen or a pointed object, the rotary arm 50 is The first long hole 20f formed in the cartridge case 20 is moved as shown in FIGS. 5B and 6.

At this time, the lock rib 54 is opened by the rotary arm 50 in an outward direction and simultaneously retracted so that the latch portion 54a locks the second protrusion 50b of the rotary arm 50. The tension rib 52 formed on the rotary arm 50 maintains a curved state.

Thereafter, when the cartridge case 20 is inserted into the recording and reproducing apparatus as described above, the operation of checking the disc state as the switch terminal 62 is inserted into the A3 spare hole 20d and the through hole 20d '. You can shorten the recording time by not running.

When the disc housed in the cartridge case is replaced or taken out by another disc, as shown in FIGS. 5C and 5D, when the lock lever 42 locked in the lock hole 20h is pressed, the lock lever 42 is pressed. The contact protrusion 42a protruding into the thrust pushes the first protrusion 50a of the rotary arm 50, and the pressing force is transmitted to the lock rib 54 by the transfer rib 56, so that the lock rib 54 is moved outward. The second protrusion 50b is released and the locking is released with respect to the latch portion 54a.

Then, the rotary arm 50 is returned to the initial position by the restoring force of the tension rib 52 integrally formed therein to block the A3 spare hole 20d again.

At the same time, the cover 40 is opened slightly with respect to the cartridge case 40 by the opening rib 48.

On the other hand, Figure 7 is a view showing a second embodiment of the disc recognition device in the disc storage cartridge according to the present invention, the cartridge is the upper and lower cases 22, 24, the shutter 30 is mounted on the front side thereof; A cartridge case (20) is formed, and a rear cover of the cartridge case (20) is hinged to a cover (70) provided with a disc recognition means to prevent the disc from being detached and check the state of the disc.

The cartridge case 20 has a plurality of positioning holes 20b, 20c, 20d and 20e positioned in diagonal directions with the positioning pin hole 20a and the rear of the positioning pin hole 20a and the first and second long holes 20f having an elliptical shape. (20 g) is formed.

The auxiliary rib 100 is integrally injected into the inner circumferential surface of the upper case 22, and the return protrusion 102 for protruding the disc recognition means to the initial position protrudes from the auxiliary rib 82.

Here, the first long hole 20f is for operating the disc recognition means, and the second long hole 20g opens and closes the protector hole 20e in order to prevent writing or erasing information on the disc. ) To operate.

Recognition holes are used to check the state of the disc and the A1 hole (20b) for confirming whether the disc first exchanged in the cartridge case 20, as described above, the A2 hole (20c) for confirming whether the disc is single-sided or double-sided. A3 spare hole 20d and a protector hole 20e for preventing information from being written to or erased from the disc.

The cover 70 is injection molded with a lock lever 72 that locks and releases the lock hole 20h formed in the cartridge case 20, and corresponds to the recognition holes 20b, 20c, 20d and 20e. Through holes 20b ', 20c', 20d ', and 20e' are formed at the positions.

The disc recognizing means inserts the switch terminal 62 into the A3 spare hole 20d according to the state of the disc or prevents the insertion of the rotary arm 74 and the rotary arm 74 to operate the switch terminal 62. It consists of a lock rib 90 extending to the lock lever 72 to lock and release it in operation.

The rotary arm 74 has a tension rib 76 and a lock protrusion 78 protruding from one end thereof so that the rotary arm 74 can be returned to its initial position when the cover 70 is opened with respect to the cartridge case 20. The extension rib 80 is integrally formed, and at one end of the lock rib 90, a latch portion 90a for locking and releasing the lock protrusion 78 is bent.

The operation of the second embodiment of the present invention will be described in detail with reference to FIGS. 8A to 8E and 9.

In the embodiment of the present invention, only the case where the disc accommodated in the cartridge case is replaced with the disc whose state is confirmed is described.

In the case where the disc accommodated in the cartridge case is replaced with a single disc in which the state of the disc is checked, as shown in FIG. 8, the rotary arm 74 is pulled forward by using a ballpoint pen or a pointed object. The lock projection 78 of the extension rib 80 formed on the rotary arm 74 moves along the first long hole 20f formed in the cartridge case 20 as shown in FIGS. 8B, 8C and 9. It is locked to the latch portion 90a of the lock rib 90.

That is, when the rotary arm 74 moves, the latch portion 90a opens outward and simultaneously retracts to lock the lock protrusion 78. At this time, the tension rib 76 formed on the rotary arm 74 maintains the curved state.

Thereafter, when the cartridge case is inserted into the recording / playback apparatus as described above, the recording / playback apparatus checks the state of the disc as the switch terminal 62 is inserted into the A3 spare hole 20d and the through-hole 20d '. You can shorten the recording time by not running the job.

When the disc accommodated in the cartridge case is checked for a disc state or replaced with a disc whose state is confirmed, the cover 70 is released by pressing the lock lever 72 to release the lock in the lock hole 20h. ) Is slightly opened with respect to the cartridge case 20 by the restoring force of the open rib 48.

Thereafter, when the cover 70 is pulled out, the latch portion 90a is in contact with the return protrusion 102 protruding inwardly to the upper case 22 and at the same time maintains an outwardly extended state.

Accordingly, the lock projection 78 locked to the latch portion 90a is returned to its initial position by the restoring force of the tension rib 76 to again block the A3 spare hole 20d so that the disk of the disc in the recording and reproducing apparatus can be restored in the above-described manner. The user can adjust whether or not to check the status.

Fig. 10 shows a third embodiment of the disc recognizing apparatus according to the present invention, wherein the cartridge is a cartridge case 20 consisting of upper and lower cases 22 and 24 on which a shutter 30 is mounted on its front side. The cover 110, which is provided with a disc recognition means, is hingedly coupled to the rear side of the cartridge case 20 to prevent the disc from being detached and to check the state of the disc.

The upper and lower cases 22 and 24 are receiving holes 22b and 24b for entering the turntable and the chucking clamper of the recording and reproducing apparatus, and opening holes 22c and 24c for securing the transfer path of the optical pickup apparatus. It is formed to communicate with each other.

The cartridge case 20 has a plurality of positioning holes 20b, 20c, 20d and 20e positioned in diagonal directions with the positioning pin hole 20a and the rear of the positioning pin hole 20a and the first and second long holes 20f having an elliptical shape. (20 g) is formed.

An inclined rib 104 inclined at a predetermined angle protrudes from the bottom surface of the lower case 24 to return the disc recognition means to the initial position.

The recognition holes are A1 and A2 holes 20b and 20c, A3 spare holes 20d and protector holes 20e as described above.

The cover 110 is injection molded with a lock lever 112 that is locked and released with respect to the lock hole 20h formed in the cartridge case 20, and corresponds to the recognition holes 20b, 20c, 20d, and 20e. Through holes 20b ', 20c', 20d ', and 20e' are formed at the positions.

The disc recognizing means inserts the switch terminal 62 into the A3 spare hole 20d according to the state of the disc, or the rotation arm 116 to which the tension rib 114 is connected so that the switch terminal 62 can be operated by preventing the insertion. ) And a lock portion 122 for locking and releasing the rotary arm 116.

An extension rib 118 extends on an outer circumferential surface of the rotary arm 116, and a lock protrusion 120 having a tapered portion 120a protrudes from an upper end thereof.

The lock portion 122 has a lock holder having a variable rib 124 integrally injection-molded to the cover 110 and an opening 126a protruding downward from the front end thereof to lock and / or release the lock protrusion 120. 126 and the lock holder 126 is provided with a contact projection 128 protruding toward one side thereof and one end thereof in contact with the inclined rib 104.

The operation of the third embodiment of the present invention will be described in detail with reference to FIGS. 11 and 12.

In the embodiment of the present invention, as in the second embodiment, only the case where the disc accommodated in the cartridge case is replaced with the disc whose condition is confirmed is described.

When storing the disc of which the disc state has been checked in the cartridge case and not performing the operation of checking the disc state, the rotary arm 116 along the first hole 20f formed in the cartridge case 20 is carried out. Move forward

Then, a portion of the lock protrusion 120a including the tapered portion 120a protruding on the extension rib 118 of the rotary arm 116 passes through the opening 126a as shown in FIG. Locked. At this time, the tension rib 114 formed on the rotary arm 116 maintains a curved state.

Thereafter, when the cartridge case is inserted into the recording and reproducing apparatus as in the first and second embodiments, the state of the disc as the switch terminal 62 is inserted into the A3 spare hole 20d and the through hole 20d '. It is possible to reduce the recording time by not performing the operation of checking tracks and sectors).

In addition, when replacing the disc housed in the cartridge case with another disc, when the lock lever 112 locked in the lock hole 20h is pressed and released, the variable rib 124 pulls on the cover 110. Since the protruding contact protrusion 128 moves along the inclined rib 104 of the lower case 24, the protruding contact protrusion 128 is bent upward.

Accordingly, only the taper portion 120a of the lock protrusion 120 is maintained in the lock holder 126 so that the locking is easily released from the lock holder 126. That is, the diameter of the tapered portion 120a is smaller than the inner diameter of the lock holder 126 so that the tapered portion 120a easily exits through the opening 126a of the lock holder 126.

Although the present invention applies the disc recognition device to a cartridge accommodating a 12 cm disc, the disc recognition device can be applied to an adapter combining a small cartridge containing a disc with a diameter of less than 12 cm and a small cartridge.

As described above, according to the disc storage cartridge having the recognition apparatus according to the present invention, the disc is stored in the cartridge case in which the disc state is checked by executing the checking operation according to the state of the disc exchanged and stored in the cartridge case. In this case, the recording / playback apparatus can recognize the state of the disc, thereby reducing the recording time.

The present invention is not limited to the above-described specific preferred embodiments, and various modifications can be made by any person having ordinary skill in the art without departing from the gist of the present invention claimed in the claims. Of course, such changes will fall within the scope of the claims.

Claims (11)

A cartridge having receiving holes on the upper and lower surfaces thereof so that the disk is accommodated; A shutter mounted to the front side of the cartridge to open and close the accommodation hole; A cover coupled to the cartridge to prevent separation of the disk; And a disc recognizing device provided in the cover and having a disc recognizing device for checking a state of the disc. The disk recognition apparatus according to claim 1, wherein the cartridge includes a cartridge case including a plurality of recognition holes positioned diagonally behind each other and upper and lower cases formed with first and second holes. Having a disk storage cartridge. 3. The disc storage cartridge according to claim 2, wherein the upper case includes a return protrusion for returning the disc recognition means to an initial position. 3. The disc storage cartridge according to claim 2, wherein the lower case includes an inclined rib to return the disc recognition means to an initial position. The disk having a disk recognition apparatus according to claim 1, wherein the disk recognition means comprises a rotary arm for opening and closing the recognition hole while moving along the first hole, and a lock rib for locking and releasing the rotary arm. Storage cartridge. 6. The disc storage cartridge according to claim 5, wherein a projection protrudes from an outer circumferential surface of the rotary arm so as to be locked to the lock rib. 4. The disc storage cartridge according to claim 3, wherein the rotary arm is provided with an extension rib having a lock protrusion at one end thereof so as to be locked to the lock rib. 4. The disc storage cartridge according to claim 3, wherein the rotary arm is provided with an extension rib having a lock protrusion having a tapered portion protruding from the end thereof so as to be locked to the lock rib. 4. The disc recognition according to claim 3, wherein the lock rib is bent and a latch portion for locking and releasing the protrusion is connected to a semi-circular transfer rib for transmitting a pressing force generated when the cover is opened to the lock rib. A disc housing cartridge having a device. The disc storage cartridge according to claim 1, wherein the disc recognition means includes a lock portion for locking and releasing the rotary arm. The lock part of claim 10, wherein the lock part comprises a lock holder having a variable rib integrally injection-molded in the cover and an opening protruding from a tip of the variable rib, and a contact protrusion protruding to one side of the lock holder. A disc storage cartridge having a disc recognition device.