Cartridge case for a disk

A cartridge case for a disk in which an optical disk is adapted to be rotatably housed in the case provided in both lateral sides thereof with openings and at an end thereof with a guide groove, and in which a slider having a shutter for opening and closing the openings of the case with the use of opening pins, is slidably disposed in the guide groove. The guide groove has a V-shape section in order to enhance the strength of the guide walls. To smoothly reciprocate the shutter, either the shutter or the slider is provided at an end thereof with a wide inclined surface which is fit for the guide groove and inclined toward the inside thereof.

FIELD OF THE INVENTION 
The present invention relates to a cartridge case for housing a disk such 
as an optical disk or a magneto-optical disk. 
BACKGROUND OF THE INVENTION 
Optical disks are known as reliable optical recording media capable of 
recording information in high density. Such optical disks are available in 
a single-sided type, that is, information may be recorded on one side of 
the disk and the information thus recorded may be reproduced, and in a 
double-sided type, that is information may be recorded on both sides of 
the disk and the information thus recorded may be reproduced. The latter 
optical disk is usually used, as rotatably housed in a cartridge case, for 
recording information and reproducing the information thus recorded. 
Referring to FIGS. 6 and 7, an optical disk 31 of the double-sided type is 
provided at the center thereof with a clamping hub 32 for rotating the 
optical disk 31 through a rotary system of a drive mechanism (not shown). 
The optical disk 31 is rotatably housed in a case 33 provided in both 
lateral sides thereof with openings 34. The case 33 includes a first case 
member 33a and a second case member 33b. As shown in FIG. 7, a guide 
groove 35 is formed by guide walls 36a, 36b at the lateral sides of the 
case 33 and projections 37a, 37b respectively formed on the inner surfaces 
of the guide walls 36a, 36b. The guide groove 35 is formed at one end of 
the case 33. 
A slider (not shown) is slidably disposed in the guide groove 35. A shutter 
38 for covering the openings 34 of the case 33 is attached to the slider 
by attaching means such as screws 39 or the like. The slider is normally 
pushed in one direction by a spring (not shown) disposed in the case 33. 
Formed in the slider and the shutter 38 at predetermined positions thereof 
are slots 41 with which two shutter opening pins (not shown) of the drive 
mechanism are adapted to be engaged. The shutter engaged with one of the 
opening pins is used for opening and closing the openings 34 of the case 
33 in order that both sides of the optical disk 31 may be used for 
recording information and reproducing the information thus recorded. More 
specifically, when one side of the optical disk 31 is to be used, one 
opening pin is reciprocated to open and close the openings 34 by the 
shutter 38, and when the other side of the optical disk 31 is to be used, 
the case 33 is first reversed and the other opening pin reciprocates the 
shutter 38 to open and close the the openings 34 of the case 33. 
The shutter 38 is provided at one end thereof with a turned piece 40 which 
is turned toward the inside of the guide groove 35. This turned piece 40 
is formed such that, when one opening pin reciprocates the shutter 38 for 
opening and closing the openings 34 of the case 33, the other opening pin 
which is not being used for reciprocating the shutter 38, is smoothly 
guided along the inclined surface of the turned piece 40, thereby to 
prevent the other opening pin from being caught by the shutter 38. 
The efficiency of properly moving away the opening pin which is not being 
used for reciprocating the shutter 38, depends on the width of the 
inclined surface of the turned piece 40. Accordingly, to smoothly move 
away the opening pin in the cartridge case above-mentioned, it is 
preferable to reduce the thicknesses of the guide walls 36a, 36b to 
increase the width of the turned piece 40. However, the reduction of the 
guide walls 36a, 36b in thickness results in reduced strength thereof. It 
is therefore difficult to reduce the thicknesses of the guide walls 36a, 
36b to increase the width of the turned piece 40. Thus, it is inevitable 
to reduce the width of the turned piece 40. On the other hand, when the 
width of the inclined surface of the turned piece 40 is small, the opening 
pin which is not being used may be caught by the shutter 38 when the drive 
mechanism is driven. This may prevent the shutter 38 from being opened and 
closed. 
SUMMARY OF THE INVENTION 
It is an object of the present invention to provide a cartridge case for a 
disk capable of smoothly opening and closing a shutter. 
It is another object of the present invention to provide a cartridge case 
for a disk capable of smoothly guiding and moving away the opening pin 
which is not being used, yet assuring the strength of guide walls. 
It is a further object of the present invention to provide a cartridge case 
for rotatably housing an optical disk, in particular, a both-side type 
optical disk of which both sides may be used for recording information and 
reproducing the information thus recorded. 
To achieve the objects above-mentioned, the cartridge case for a disk in 
accordance with the present invention comprises: a case for rotatably 
housing a disk; openings formed in both lateral sides of the case; and a 
guide groove formed in one end of the case. 
The case is adapted to rotatably house preferably an optical disk and more 
preferably an optical disk of the double-sided type. The guide groove has 
a V-shape section to enhance the strength of the guide walls. A slider is 
slidably disposed in the guide groove. To smoothly slide the slider, the 
slider is preferably made of a material having a small friction 
coefficient and, more preferably, polyacetal or fluororesin. A shutter for 
opening and closing the openings of the case is attached to the slider. 
Either the shutter or the slider is provided at an end thereof with an 
inclined surface which is fit to the V-shaped guide groove and inclined 
toward the inside thereof. Since the guide groove has a V-shape section, 
the inclined surface at the end of either the shutter or the slider which 
is fit for the guide groove, has a wider width. Accordingly, the opening 
pin which is not being used for reciprocating the shutter, may be smoothly 
moved away along the inclined surface having a larger area. 
These and other objects and advantages of the present invention will be 
better understood by the following detailed description with reference to 
the attached drawings.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
With reference to FIGS. 1 to 4, an optical disk of the double-sided type 
(not shown) of which both sides are used for recording information and 
reproducing the recorded information, is provided at the center thereof 
with a clamping hub (not shown) for rotating the optical disk as an 
optical recording medium through the rotary system of a drive mechanism, 
as conventionally done. The optical disk of the double-sided type has a 
transparent disk substrate, and a recording layer, a reflecting layer, a 
protective layer and the like formed on the disk substrate. 
Such an optical disk is rotatably housed in a case 1. The case 1 includes a 
first case member 1a and a second case member 1b having the same shape and 
sizes as those of the first case member 1a. The first and second case 
members 1a, 1b have openings 2a, 2b which are formed in the lateral sides 
thereof and which extend from the portions of these lateral sides opposite 
to the center of the optical disk toward the end peripheries of the first 
and second case members 1a, 1b. These openings 2a, 2b are used for 
recording information on and reproducing the recorded information from 
both sides of the optical disk with the use of a laser beam. 
As shown in FIGS. 2 and 3, the case members 1a and 1b are respectively 
provided at the ends thereof at the sides of the openings 2a, 2b with 
guide walls 3a, 3b and projections 4a, 4b. The guide walls 3a, 3b are 
thicker in the direction toward the insides thereof, and the projections 
4a, 4b are respectively formed on the inner surfaces of the guide walls 
3a, 3b. The case 1 is formed by bonding the first and second case members 
1a, 1b with integrally connecting means such as screws, or adhesives. A 
V-shape guide groove 5 is formed by the guide walls 3a, 3b and the 
projections 4a, 4b. 
A slider 6 is slidably disposed in the V-shape guide groove 5. A shutter 7 
for covering, across the guide groove 5, the openings 2a, 2b in the 
lateral sides of the case 1, is attached to the slider 6 with attaching 
means such as screws 8. Regulating portions 9, 10 for regulating a slide 
area 11 of the shutter 7 are formed at both lateral sides of the case 1 
and at both ends of the guide groove 5. 
As shown in FIGS. 1 and 4, the slider 6 is pushed to a predetermined 
direction by resilient means such as a spring 12 disposed in the case 1. 
The slider 6 has a concave portion 13. A notch 14 is formed in the shutter 
7 at its portion opposite to the concave portion 13. A slot 15 is formed 
by the concave portion 13 and the notch 14. 
With the cartridge case having the arrangement above-mentioned, information 
recording and reproduction may be carried out in the following manner. 
As shown in FIG. 4, two shutter opening pins P1, P2 of a drive mechanism 
(not shown) are adapted to be removably engaged with the slot 15. In the 
embodiment shown in FIG. 1, when one opening pin P1 engaged with the slot 
15 is reciprocated, the shutter 7 is reciprocated, causing the opening 2a 
and 2b of the case 1 to be opened and closed. This enables one side of the 
optical disk, i.e., the side B thereof, to be used for recording 
information or reproducing the recorded information. On the other hand, 
when the case 1 is reversed and the other opening pin P2 is reciprocated 
in the same manner as above-mentioned, the opening 2b and 2a of the case 1 
is opened and closed. This enables the other side of the optical disk, 
i.e., the side A in this embodiment, to be used for recording information 
or reproducing the recorded information. 
Recording information on the optical disk is generally carried out by 
irradiating a laser beam to the disk in the direction from the substrate 
to the recording layer or another layers so that information is recorded 
in the form of pit rows, phase variations and the like, in the 
circumferential direction. Reproduction of the recorded information is 
generally carried out based on variations of the reflection amount or 
penetration amount of a laser beam irradiated to the disk in the direction 
from the substrate to the recording layer or another layers. 
The shutter 7 is provided at an end thereof with a turned or bent piece 17 
having an inclined surface 16 which is fit to the guide groove 5 and which 
is inwardly inclined. Since the guide groove 5 is formed in a V-shape, the 
width of the inclined surface 16 of the turned piece 17 increases in the 
direction toward the opening of the guide groove 5. With the width of the 
inclined surface 16 of the turned piece 17 thus increased, it is possible 
to smoothly guide and move away, along the wide inclined surface 16, the 
opening pin P2 which is not being used for reciprocating the shutter 7 in 
the embodiment shown in FIG. 4. Accordingly, the opening pin P2 which is 
not being used for reciprocating the shutter 7 to open or close the 
openings 2a, 2b of the case 1, does not prevent the shutter 7 from being 
smoothly opened and closed. Further, since the guide groove 5 has a 
V-shape section and the guide walls 3a, 3b are thickened at the inward 
sides thereof, the strength of the guide walls 3a, 3b may be enhanced. 
In another embodiment of the present invention shown in FIG. 5, an inwardly 
turned inclined surface 28 is formed at the end of a slider 26, instead of 
the end of a shutter 27. Likewise as in the embodiment shown in FIG. 1, 
the slider 26 is slidably disposed in a V-shape guide groove 25 formed by 
guide walls 23a, 23b and projections 24a, 24b of a case 21. The slider 26 
is integrally attached to the shutter 27 by screws 29. The case 21 is 
formed by case members 21a, 21b. 
Likewise as in the embodiment shown in FIG. 1, the strength of the guide 
walls 23a, 23b of the case 21 may also be enhanced. Further, the opening 
pin which is not being used for reciprocating the shutter 27, may be 
smoothly guided and moved away by the wide inclined surface 28 of the 
slider 26. 
The angles of the guide walls forming the guide groove of the case may be 
suitably determined in such a range as to widen the inclined surface at 
the end of the shutter or the slider and to enhance the strength of the 
guide walls. The guide walls may be thickened in the direction toward the 
inner part of the case, not only linearly but also in a curved manner. The 
inclination angles of the guide walls may be generally set at 30.degree. 
to 85.degree., preferably at about 45.degree. to about 80.degree., with 
respect to the horizontal direction. The angle of the inclined surface at 
the end of either the shutter or the slider is set to such an angle as to 
smoothly guide and move away the opening pin which is not being used for 
reciprocating the shutter, for example to 25.degree. max. 
To smoothly reciprocate the shutter, the slider is preferably made of a 
material having a small friction coefficient. As such a material, 
polyolefin may be used, and polyacetal and fluororesin are preferred. 
The present invention may be applied to a variety of disks for recording 
information in and reproducing the recorded information from one side or 
both sides of the disk, and preferably applied to an optical disk of 
double-side type. 
The present invention may also be applied to optical disks of the read-only 
type, the additionally writable type and the rewritable type.