A disc cartridge

Abstract: A disk cartridge for double sided magnetic optical and magneto-optical recording medium. The cartridge case has a reinforcement portion along the edge of the head insertion window of reduced thickness. The shutter is mounted on a slider which has a rear portion at each end for engaging guide means either side of the reinforcement portion.

Description: The present invention relates to a disc cartridge for holding a double-sided recording type disc-like recording medium An image file system in which an optical disc (including both writable type and rewritable type) is used as a file memory has been noted because its recording density is much larger than that of other information recording medium. Thus, a variety of disc drive devices and disc cartridges suitable have been proposed for that system. Fig. 15 is a perspective view schematically showing an example of a disc drive apparatus of this type. A cartridge holder 3 is formed into a frame shape into a disc cartridge is insertable and has an opening 2, at is bottom, through which a turntable is inserted. Opening/closing arms 4 and 5 are pivotally provided at their ends to side portions on a disc cartridge stop side of the cartridge holder 3. Pins 4a and 5a coupled to these ends of the opening/closing arms 4 and 5 are disposed in a cartridge insertion path within the cartridge holder 3. The opening/closing arms 4 and 5 are normally biased by springs (not shown) in a direction in which the disc cartridge 6 is discharged from the cartridge holder 3. The opening/closing arms 4 and 5 are rotated inwardly (in the directions indicated by arrows A and B) by the insertion of the disc cartridge 6. When the disc cartridge 6 is discharged from the cartridge holder 3, the arms 5 and 6 are automatically returned back to the original positions. On the other hand, in the disc cartridge 6 adapted to this optical disc drive apparatus, as shown in Figs. 16 and 17, a window 10 for insertion of the head and the turntable are formed in a portion from a central portion to a front edge 9 of a cartridge half 8 which rotatably receives a both-sided recording type optical disc 7. A shutter 11 is slidably mounted for closing/opening the window 10 along the front edge 9. The both-sided recording type optical disc 7 is formed by bonding two optical disc elements with their recording layers facing each other. In the front edge 9 of the disc cartridge 6, a sliding portion 12 is recessed for sliding movement of the above-described pins 4a and 5a. Further, a recessed portion 13 contiguous with the sliding portion 12 is formed so that the recessed portion 13 may come into contact with the pin 4a or 5a. Cutouts 14 are formed in sides of the disc cartridge 6 for positioning the disc relative to the cartridge holder 3. At corner portions close to a rear edges 15 of the upper and lower halves 8a and 8b, erroneously erasing proof mechanisms 16 and 17 are formed in a symmentrical manner with respect to a center line C-C of the window 10. As shown in Fig. 16, the window 10 is closed by the shutter 11 in the non-use condition of the disc cartridge 6, i.e., the condition in which the disc cartridge 6 is not inserted into the cartridge holder 3. Thus, foreign matters may be prevented from entering through the window to protect the optical disc 7. When the disc cartridge 6 is inserted into the cartridge holder 3 up to a predetermined position, as shown in Fig. 17, the shutter 11 is moved by a predetermined distance in the direction D to thereby open the window 10. At this time, the pin 4a falls in the recess 13 formed in the front edge 9 to thereby position the shutter 11 at the predetermined position. Simultaneously therewith, a sensor (not shown) provided in the cartridge holder 3 will detect the insertion of the disc cartridge 6 at the predetermined position. The cartridge holder 3 is lowered and the optical disc 7 is clamped on the turntable 1 to thereby complete the loading of the disc cartridge 6. It should be noted that an example of a conventional cartridges is used in which a cutout 19 is formed in a front face of a shutter 11, and a pin 5a or 5b is engaged with the cutout to thereby open and close the shutter as shown in Figs. 18a and 18b. It is also to be noted that, since a width W of the window 10 of an optical disc cartridge is larger than that of a magnetic disc cartridge (for a floppy disc), the amount of movement of the shutter 11 for opening/closing the window 10 becomes larger. In order to increase the amount of movement of the shutter 11, it is necessary to increase a length L of the arms 4 and 5 and to decrease an angle  defined between a line E-E connecting the pivot 4b, 5b and the pin 4a, 5a to each other and a line F-F in conformity with the disc cartridge insertion direction (which angle will be referred to as an initial set angle). However, if the length L of the arms 4 and 5 is increased, there is a disadvantage such that the disc drive apparatus is made large in size. On the other hand, if the initial set angle  is decreased, a collision force generated when the front edge 9 of the disc cartridge 6 is brought into abutment with the pin 4a, 5a is increased, and at the same time, the opening/closing operation of the shutter 11 needs a large force, resulting in degradation in operational feeling. If the initial set angle  is increased, then it is possible to avoid or suppress the foregoing disadvantage. However, inversely, the amount of movement of the shutter 11 will become small. It is therefore difficult to apply this to the optical disc drive apparatus. Incidentally, in the magnetic disc drive apparatus, there has been provided a structure in which the arms are mounted on an upper surface of the cartridge holder 3 to thereby miniaturize the apparatus as in, for example, Japanese Patent Unexamined Publication 59-2269. However, in this magnetic disc drive apparatus, there is no means for mounting the disc cartridge in a reversible manner. It is impossible to apply this to the optical disc drive apparatus for driving the both-sided recording type optical disc. Turning to the apparatus for the disc shown in Figs. 18a and 18b, since the opening/closing arms 4 and 5 must be crossed in the midway of the shutter opening/closing operation, it is difficult to increase a size of the cutout 19. As a result, the engagement between the cutout 19 and the pin 4a, 5a would be insufficient, so that the engagement therebetween is likely to be released. In particular, in a small size disc cartridge in which the size of the cutout is restricted, such a disadvantage is remarkable. It is impossible to put this system into practical use. A similar device is disclosed in US 4,811,137. EP 0 218 231 discloses a disc cartridge according to the pre-characterising portion of claim 1. The present invention provides a disc cartridge with an improved slider arrangement. According to the present invention, there is provided a disk cartridge adapted to be loaded between two opposed heads of a disk drive the cartridge comprising: a cartridge case having a space therein for receiving a disk rotatably, a shutter plate-receiving recess in either side thereof for allowing a shutter-plate means to slide therein, the shutter plate-receiving recess extending rearward from a front edge of the cartridge case, a head insertion window formed in each of the shutter plate-receiving recesses, a front end of each window being defined a reinforcement portion constituting a part of the front edge of the cartridge case, the reinforcement portion having a stepped cut-out portion, of a thickness smaller than a thickness of the cartridge case at the shutter plate-receiving recess, in at least a part thereof and in at least one side of the cartridge case so that the stepped cut-out portion can be passed through a spacing between the two heads of the disk drive upon loading the disk cartridge into the disk drive, and guide means, for guiding a sliding motion of a slider, formed in the front edge of the cartridge case at either side of the reinforcement portion; a slider mounted to the front edge of the cartridge case; and the shutter-plate means, mounted on the slider, for covering and uncovering each of the windows upon sliding movement of the slider relative to the cartridge case, said disc cartridge characterised in that the slider includes: a front portion situated at a fronted position, in a loading direction of the disk cartridge, of the slider and having a head insertion portion adapted to be situated at the front end of the window when the shutter-plate means is moved to an uncovering position for fully uncovering the window and having a thickness small enough to be passed through the spacing between the two heads upon loading the disk cartridge into the disk drive, a shutter-moulting portion situated at one end side of the head insertion portion and having a thickness greater than the thickness of the head insertion portion, the shutter-plate means being fixed to the slider at the shutter-mounting portion of the slider, and a pin-engagement portion situated at the other end of the head insertion portion and having a thickness greater than the thickness of the head insertion portion; and a pair of rear portions situated at a rear position, in the loading direction, of the slider relative to the front portion, and connected respectively to said pin-engagement portion of the front portion and a part, of the shutter-mounting portion of the front portion remote from the pin engagement portion, through a respective one of a pair of connection portions, so that each of the pair of rear portions and the respective one of the connecting portions can move within respective ones of the guide means, upon sliding movement of the slider associated with covering and uncovering motion of the shutter-plate means, each of the connecting portions having a thickness smaller than a thickness of the associated rear portions thereby defining at either side thereof a guide step to be engaged with the respective guide means so that the sliding movement of the slider (22) can be guided. The present invention will be further described hereinafter within reference to the following description of an exemplary embodiment and the accompanying drawings in which : Figs. 1 to 10 are illustrations of a disc cartridge which is described for reference purposes, Fig. 1 is a perspective view showing the disc cartridge; Fig. 2 is a plan view showing a lower half; Fig. 3 is a cross-sectional view showing the lower half; Fig. 4 is frontal view of the lower half; Fig. 5A is a front view showing the cartridge case; Fig. 5B is a front view showing the disc cartridge; Fig. 6 is a perspective view showing the shutter; Fig.7 is a side elevational view showing the shutter; Fig.8 is a side elevational view showing a slider; Fig.9 is a front view showing the slider; and Fig.10 is a plan view showing the slider; Fig. 11 is a plan view showing a slider of a cartridge case according to the invention; Fig. 12 is a front view showing the cartridge case of the invention; Figs. 13 and 14 are plan views showing the engagement condition between the slider and the cartridge case; Figs. 15 to 18A and 18B are illustrations of the prior art; Fig. 15 is a perspective view showing a cartridge holder; Figs.16 and 17 are views showing the operation; and Figs.18A and 18B are plan views showing the other disc cartridge. Before explaining the present invention, one example of a disc cartridge for use in a disc drive apparatus will now be explained with reference to Figs. 1 to 10, in which the members and components shown in Figs. 15 to 16 are designated by the same reference numerals or characters. As shown in Fig. 1 , the disc cartridge 6 is composed essentially of a cartridge case 21 made of hard plastic, an optical disc 7 of both-sided recording type rotatably received within the cartridge case 21, a slider 22 slidably mounted along a front edge 9 of the cartridge case 21, a shutter 11 fixed to the slider 22 for sliding in one direction from a closed position to open/close a window 10 formed in the cartridge case 21, and a shutter holding plate 18 holding the edge portion of the shutter 11. As shown in Fig. 1 , the cartridge case 21 is composed of an upper half 8a and a lower half 8b. The two halves 8a and 8b are bonded together by using a plurality of screws (not shown) to thereby define a space for receiving the optical disc 7 and the other structural members. As shown in Fig. 2 , in the lower half 8b, there is formed the elongated window 10 extending from a central portion corresponding to the center P of rotation of the optical disc 7 to the front edge 9 (i.e., a side edge facing the insertion side toward the disc drive apparatus). The openings 16a, 17a for an erroneous erasure preventing mechanism are symmetrically provided on the both sides in the lower half 8b near the rear end portion 9a. A width W of the window 10 is determined such that the turntable for drivingly rotating the optical disc 7 and the head for recording/ reproducing informations for the optical disc may be inserted into the window 10. As shown in Figs. 2 and 3, a coupling wall 23 having a constant height is formed along an outer peripheral edge other than the front edge 9 of the lower half 8b. In addition, partitioning walls 24 having the same height as that of the coupling wall 23 are formed in a ring on a circumference about the rotational center P of the optical disc 7. Thus, receiving space 24a for the optical disc 7 is formed. Further, on a circumference about the rotational center P of the window 10 is formed in a ring an annular projection 10a for a disc, having a lower height than the heights of the coupling wall 23 and the partitioning walls 24. A guide rail 25 having a height somewhat lower than that of the coupling wall 23 and the partitioning walls 24 is linearly formed in the front edge 9 of the lower half 8b. A stepped portion 25a for stopping the shutter is formed at an end portion of the guide rail 25 on the shutter closed side. Another coupling wall 26 having the same height as that of the walls 23 and 24 is formed in parallel with the guide rail 25 inside of the guide rail 25. As shown in Fig. 4 in confronted relation to the window 10 of the front edge of the lower half 8b, a reinforcement portion 27 recessed from the surface of the lower half 8b is formed integrally to be flush with the end portion of the guide rail 25. As shown in Fig. 4 at an outer portion of the lower half 8b where the shutter 11 is sliding moved, there is formed a recess 28 for retracting the surface of the shutter 11 within the surface of the lower half 8b. On the other hand, the upper half 8a is formed in the same shape as that of the lower half 8b except that the respective components of the upper half 8a are formed in symmentrical positions with those of the lower half 8b. Accordingly, if these halves 8a and 8b are coupled to each other, as shown in Figs. 5(a) and 5(b) , a slider insertion hole 29 are linearly formed in the coupling portion of the front edge 9. A structure of the shutter 11 will now be explained. As shown in Figs. 6 and 7, by bending a thin plate made of stainless steel or the like into a U-shape, the shutter 11 has an upper portion 11a and a lower portion 11b having such a length that the portions 11a and 11b may simultaneously cover the entire portion of the window 10, and a front portion 11c having substantially the same width as a thickness S of the shutter setting portion of the cartridge case 8. Retaining claws 30 are bendingly formed in wardly in the portions of the upper portion 11a and the lower portion 11b close to the front portion 11c. As shown in Fig. 8 the slider 22 is composed of a front face portion 31 having a large width, a rear face portion 32 having a small width, and a connecting portion 33 coupling the front and rear face portions 31 and 32 to each other. The slider 22 embraces the guide rails 25 within concave grooves 34a and 34b formed by these portions. As shown in Figs. 9 and 10 the front face portion 31 is composed of a head insertion portion 35 having a length ℓ which is somewhat larger than the width W of the window 10 and a width T 2 which is equal to or narrower than a thickness T 1 of the reinforcement portion 27, a shutter mounting portion 36 having substantially the same width as an inner width of the shutter 11, a tapered portion 37 formed at an end portion of the shutter mounting portion 36, and a pin engagement portion 37a formed opposite the shutter mounting portion 36 through the head insertion portion 35. The pin engagement portion 37a has substantially the same as that of the shutter mounting portion 36. A recessed portion 38 for mounting the shutter 11 is formed over the front face and upper and lower surfaces of the shutter mounting portion 36. Further, recessed portions 39 are formed in the central portions of the upper and lower surfaces of the shutter mounting portion 36 for facilitating the engagement with the retainer claws 30 formed in the shutter 11 by bending. Furthermore, recessed portions 40 for receiving the retainer claws are formed in the bottoms of the recessed portions 39 for engagement with the retainer claws of the shutter mounting portion 36. The rear face portion 32 has a constant width over its overall length as viewed from the rear side of the slider 22, and a spring retainer portion 32b projects from the end of the rear face portion 32 on the side of the tapered portion 37 as best shown in Fig. 10. The slider 22 is integrally formed of synthetic resin which is superior in sliding property, such as nylon or polyacetal. The shutter 11 is mounted on the slider 22 by the engagement of the retainer claws 30 with the shutter mounting portion 36. The slider 22 is slidably mounted on the cartridge case 21 with the tapered portion 37 being directed in the moving direction of the shutter 11 for opening and with the recessed grooves 34a and 34b being engaged with the rails 25. In this case, the upper portion 11a and the lower portion 11b of the shutter 11 are laid on the upper and lower surfaces of the cartridge case 21, respectively so as to close the respective windows 10 formed in the upper and lower halves 8a and 8b. The edge portions of the shutter 11 are held in intimate contact with the cartridge case 21 by elongated holding plates 42 attached to the cartridge case 21. The stepped portion 25a for stopping the shutter 11 is formed in such a positional relation that the side portion of the shutter 11 is not contacted with the end face of the recessed portion 28 when the end face of the slider 22 is contacted with the stepped portion 25a. With such an arrangement, it is possible to reduce an amount of debris generated upon the abutment between the shutter 11 and the cartridge case 21. In the above described cartridge the rear face portion 32 and the connecting portion 33 of the slider 22 are formed over the almost full length of the slider. In the invention, the rear face portions 32 and the connecting portions 33 are formed only at the two-end portions of the slider 22, as shown in Fig. 11. With such a slider it is possible to use a cartridge case 21 where slider insertion holes 29 are formed only on the both-end portions through the reinforcement portion 27 as shown in Fig. 12. In some embodiments, as shown in Fig. 13 , a stopper 103 and a guide portion 104 are formed in the longitudinal direction of the slider 22 from each end portion, and the end portion of the stopper 103 is brought into contract with the connecting wall 23 formed in the cartridge case 21, whereby it is possible to limit the set position of the shutter 11 when the window 10 is closed. In other embodiments, as shown in Fig. 14, the slider 22 is not brought into contact with the connecting wall 23 of the cartridge case 21 but with a projection 105 formed at an inner surface of the cartridge case 21 whereby it is possible to limit the set position of the shutter 11 when the window 10 is closed. The present invention may be applied to magnetic disc cartridges as well as the optical disc cartridges

Claims: A disk cartridge adapted to be loaded between two opposed heads of a disk drive, the cartridge comprising: a cartridge case (8a,8b) having :- a space therein for receiving a disk rotatably, a shutter plate-receiving recess in either side thereof for allowing a shutter-plate means (11) to slide therein, the shutter plate-receiving recess extending rearward from a front edge of the cartridge case (8a,8b), a head insertion window (10) formed in each of the shutter plate-receiving recesses, a front end of each window (10) being defined by a reinforcement portion (27) constituting a part of the front edge of the cartridge case (8a,8b), the reinforcement portion (27) having a stepped cut-out portion, of a thickness smaller than a thickness of the cartridge case (8a,8b) at the shutter plate-receiving recess, in at least a part thereof and in at least one side of the cartridge case (8a,8b) so that the stepped cut-out portion can be passed through a spacing between the two heads of the disk drive upon loading the disk cartridge into the disk drive, and guide means, for guiding a sliding motion of a slider (22), formed in the front edge of the cartridge case (8a,8b) at either side of the reinforcement portion (27); a slider (22) slidably mounted on the front edge of the cartridge case (8a,8b); and the shutter-plate means (11), mounted on the slider (22), for covering and uncovering each of the windows (10) upon sliding movement of the slider (22) relative to the cartridge case (8a, 8b), said disk cartridge characterised in that the slider (22) includes: a front portion (31) situated at a front position, in a loading direction of the disk cartridge (6), of the slider (22) and having a head insertion portion (35) adapted to be situated at the front end of the window (10) when the shutter-plate means (11) is moved to an uncovering position for fully uncovering the window (10) and having a thickness (T2) small enough to be passed through the spacing between the two heads upon loading the disk cartridge into the disk drive, a shutter-mounting portion (36) situated at one end side of the head insertion portion (35) and having a thickness greater than the thickness (T2) of the head insertion portion (35), the shutter-plate means (11) being fixed to the slider (22) at the shutter-mounting portion (36) of the slider (22), and a pin-engagement portion (37a) situated at the other end of the head insertion portion (35) and having a thickness greater than the thickness (T2) of the head insertion portion (35); and a pair of rear portions (32; 103,104) situated at a rear position, in the loading direction, of the slider (22) relative to the front portion (31), and connected respectively to said pin-engagement portion (37a) of the front portion (31) and a part of the shutter-mounting portion (36) of the front portion (31) remote from the pin engagement portion (37a), through a respective one of a pair of connection portions (33), so that each of the pair of rear portions (32) and the respective one of the connecting portions (33) can move within respective ones of the guide means upon sliding movement of the slider (22) associated with covering and uncovering motion of the shutter-plate means, each of the connecting portions (33) having a thickness smaller than a thickness of the associated rear portions (32) thereby defining at either side thereof a guide step to be engaged with the respective guide means so that the sliding movement of the slider (22) can be guided. A disk cartridge according to claim 1, wherein at least one (103,104; 104) of the two rear portions projects longitudinally further than the corresponding longitudinal end of the front portion (31) so as to stop a sliding motion, of the shutter-plate means (11), in the direction of the projected end by abutment thereof with a part of cartridge case (8a, 8b). A disk cartridge according to claim 1, wherein both of the rear portions (103, 104) project longitudinally further than the corresponding longitudinal ends of the front portion (31) so as to stop a sliding motion, of the shutter-plate means (11), the direction of each of the respective projected end of the rear portions (103,104) by abutment thereof with an associated part of cartridge case (8a,8b). A disk cartridge according to claim 1, 2 or 3, wherein the thickness (T2) of the head insertion portion (35) of the slider (22) is not greater than a thickness (T1) of the reinforcement portion (27), the thickness of the pin-engagement portion is not greater than a thickness (S) of the cartridge case (8a,8b) outside of the shutter-receiving recess, and the shutter-mounting portion (36) has a recessed portion for mounting the shutter-plate means (11), the recessed portion being formed of at least one surface selected from a front face, an upper surface and a lower surface. A disk cartridge according to any one of claims 1 to 4 further comprising a disk-shaped magnetic recording medium A disk cartridge according to any one of claims 1 to 4 further comprising a disk-shaped optical recording medium

Inventors: SUGIYAMA TOSHINORI, TANAKA YOSHITO, TSUBURAYA YOSHITANE, SUGIYAMA, TOSHINORI, TANAKA, YOSHITO, TSUBURAYA, YOSHITANE
Applicants: HITACHI MAXELL, HITACHI MAXELL LTD.
Application year: 1990
Main classification: G11B23
IPC codes: G11B17