JP3077146U - Optical disc playback adapter - Google Patents

Abstract

(57) [Summary] [PROBLEMS] Even in an optical disc reproducing apparatus provided with a disc holder, such as a so-called barrel-shaped or rectangular small disc, which is incompatible with a small-sized optical disc not conforming to the standard of popular compact discs, such small discs cannot be used. Provided is an adapter for reproducing an optical disk which is capable of reproducing and which is easy to attach and detach. SOLUTION: An annular portion 1 made of an elastic hard synthetic resin having the same diameter as a standard-size compact disk standard optical disk,
The barrel-shaped small disk is rotatably inserted from the disk rotation guide insertion hole 10 and is rotatably closed by the rotary sliding closing surface 9 while being sandwiched by the eave-shaped projections 5 to 8. Fitted in the fitting area 16, the corner holding pieces 17a,
b and the annular erection piece 18 sandwich the extending plate portion 15 to the four corners 15a to 15d, and the narrow annular hill-like projection of the rectangular small disk reproducing surface is closely fitted in the annular vacant space 19;
It is mounted detachably.

Description

[Detailed description of the invention]

[0001]

[Technical field to which the invention belongs]

 The present invention relates to an adapter for reproducing an optical disk.

[0002] An optical disk as an information storage medium is a business card-sized rectangle, or a barrel-shaped optical disk of the same size as such a business card-sized rectangle, that is, a small-sized compact disk standard optical disk is arranged concentrically at the center, and the center is located at the center. A disk cut by two parallel lines at a predetermined equidistant distance has been on the market in recent years, but disk holders that are not compatible with optical disks of such a shape, such as vertically inserted disk holders, are provided. There is also an optical disc playback device. The present invention relates to an optical disk reproducing adapter for a reproducing apparatus having a vertically inserted disk holder excluding a slot interface among such optical disk reproducing apparatuses.

[0003]

[Prior art]

 The prior art related to the present invention is an optical disc playback adapter for adapting a small-format compact disc standard optical disc, a so-called single-format optical disc, to a popular compact disc standard disc optical disc holder, and is an overall view of the use of the adapter. As shown in FIG. 4, a rigid synthetic resin material having elasticity is formed in an annular shape, and the outer diameter of the annular portion 100 is a standard outer diameter L of a compact disk, that is, a general-purpose configuration of an optical disk reproducing apparatus. The outer diameter L conforms to the standard optical disc holder, which is a standard-sized compact disc standard element, and the central circular air space 101 surrounded by the annular portion 100 has a small-sized compact disc standard outer diameter M, that is, a small-sized compact disc. It is almost the same as the outer diameter M of the standard compact disc optical disc S. The disc is removably mounted on the center space 101 at the same center, and the mounting and fixing means integrally forms a leaf spring portion 102, and a synthetic resin material generated in the leaf spring portion 102. The edge s of the small-sized compact disc standard optical disc S is sandwiched by utilizing the elasticity of the elastic disc.

[0004]

[Problems to be solved by the invention]

 The above-mentioned prior art is applicable only to a small-format compact disc standard optical disc, that is, a single-format optical disc. The barrel-shaped small disk or rectangular small disk which is arranged and cut by two parallel lines at a predetermined equidistant distance from the center, that is, the small disk of the above-mentioned barrel-shaped small disk is outside the standard size of the compact disk. Discs that are formed in a thin annular shape and have extended plate portions at the four corners and are not suitable for rectangular small discs with a rectangular shape, especially for vertically inserted disc holders, etc. There was a problem that these small discs could not be reproduced by an optical disc reproducing apparatus provided with a holder.

[0005] In view of such problems, the present invention provides an optical disk reproducing apparatus provided with a disk holder that is not compatible with a small-sized optical disk not conforming to the standard of a popular-format compact disk, such as a so-called barrel-shaped or rectangular small disk. An object of the present invention is to provide an optical disk reproducing adapter which can reproduce these small disks and is easy to attach and detach.

[0006]

[Means for Solving the Problems]

 According to the present invention, the outer diameter of the annular portion is made of a rigid synthetic resin material having elasticity, and the outer diameter of the annular portion is the standard outer diameter of a compact disc, that is, the popular compact which is a general-purpose component of an optical disc reproducing apparatus. The standard outer diameter of the optical disk holder conforms to the standard optical disk holder, and the central circular air space surrounded by the annular portion is substantially equal to the outer diameter of the small-format compact disk standard optical disk. Therefore, a removable optical disk adapter that has a configuration in which a small optical disk, which has a smaller area than a standard-format compact disk optical disk, is mounted in the center airspace at the same center as the removable optical disk is detachable. The target small optical disk is the same as a barrel-type small disk, that is, a small-format compact disk standard optical disk. It is a small barrel-shaped disk which is arranged at the center and is cut by two parallel lines at a predetermined equal distance from the center, or a rectangular small disk, that is, a small-sized compact disk standard of the barrel-shaped small disk. The barrel may be a small rectangular disk having a hill-shaped protrusion formed in a thin annular shape at a portion corresponding to the outer diameter edge, and an extended plate portion provided at each of the four corners and having a rectangular shape. The barrel-shaped small disk holding means for holding the small disk edge area and the rectangular small disk holding means for holding the rectangular small disk edge area are both formed in the adapter annular portion. To solve major issues.

[0007] Based on the configuration of the above-mentioned main problem solving means, the present invention provides a barrel-shaped small disk holding means, wherein the barrel-shaped small disk holding means is configured such that the barrel-shaped small disk holding means is located between the inner edge of the central circular airspace of the adapter and the inner edge of the central circular airspace. The rectangular small disk holding means includes four rectangular corners of the rectangular small disk, or four rectangular corners of the rectangular small disk and the rectangular plate and the extending plate portion. A notch portion to be fitted is provided, and a disk fitting area including the notch portion is formed into a rectangular shape slightly larger than the shape of the rectangular disk. A corner holding piece formed in the notch portion, The annular erection piece installed on the portion constitutes a rectangular small disk holding means, and the annular erection piece can take a configuration of surrounding the hill-shaped projection.

In order to improve the convenience and fixing degree of mounting the small barrel-shaped disk, the present invention is based on the configuration of the above-mentioned problem solving means, and the upper and lower eaves holding the small barrel-shaped disk are formed. The protruding piece constitutes a disk rotation guide together with the inner surface of the thick portion of the adapter annular portion, and the upper eaves-shaped notch cutout portion of the disk rotation guide is longer than the circumference of one circle of the small barrel-shaped disk. The disk rotation guide may be provided at an appropriate position of the disk rotation guide.

Although the barrel-shaped small disk has a flaky shape, difficulties remain in mounting the adapter in many cases. However, in order to make the mounting easier, the present invention employs an eaves-shaped upper part of the disk rotation guide. It is also possible to solve the above-mentioned problem by leaving a lower eave-shaped projection at an appropriate position of the projection notch to serve as a disk mounting projection, and the disk mounting projection constitutes a guide for insertion into a disk rotation guide. This is a means for solving the problem accompanying the means.

[0010] In addition, in order to improve the convenience of mounting and the degree of fixation in visual recognition, the present invention provides an insertion start position indicating means for indicating the insertion position of the disk rotation guide, and a stopper position for indicating the installation position of the disk rotation stopper means. At least one of the display means can be configured to be provided on the adapter annular portion.

[0011] With the above configuration, when playing back a small barrel-shaped disk in an optical disk playback device provided with a vertically inserted disk holder, the small barrel-shaped disk is surrounded by a central circular airspace surrounded by an annular portion of the adapter. And play it. Since the outer diameter of the adapter annular portion is the same as that of the standard-format compact disc optical disc, it can be reproduced in the same manner as the standard-format compact disc optical disc.

As described above, when the barrel-shaped small disk can be reproduced, that is, when the barrel-shaped small disk is mounted on the center circle of the adapter, the peripheral edge of the barrel of the barrel-shaped small disk is raised upward so as not to hinder the reproduction. By sandwiching between both lower eaves-shaped projections.

[0013] The upper and lower eaves-shaped protruding pieces, together with the inner surface of the thick portion of the adapter annular portion, serve as a rotation guide while pinching the circular peripheral edge of the small barrel-shaped disc, so that the pinching is good. Rotate the small barrel-shaped disk to the position, and mount it in a good clamping position.

However, in order for the small barrel-shaped disk to slide while being loaded with the disk rotation guide, the small barrel-shaped disk must be inserted into the disk rotation guide. For this reason, in the present invention, the notch portion of the upper eave-shaped projection of the disk rotation guide is set to be longer than the circumference of one circle of the small barrel disk so that the small disk can be inserted into the disk rotation guide. Configuration. It is preferable that two cutout portions of the upper eave-shaped protruding piece of the disk rotation guide be provided symmetrically with respect to the center of the disk or the adapter.

In this way, the barrel-shaped small disk is rotated and slid while being pinched by the disk rotation guide, and is provided at an appropriate position so that the disk can be pinched satisfactorily. If the disk is rotated and slid to the disk rotation stopper means, the clamping and fixing degree of the barrel-shaped small disk is further improved. The procedure for removing the small barrel-shaped disk from the adapter may be the reverse procedure.

Since the small barrel-shaped disk is a flaky article, it is somewhat difficult to insert the disk into the disk rotation guide. Is left as a disk mounting projection, this disk mounting projection serves as a guide for insertion into the disk rotation guide, and insertion into the disk rotation guide becomes easy.

Further, the upper and lower eave-shaped projections constituting the disk rotation guide have a considerably small width so as not to hinder the reproduction of the disk. Therefore, the position at which the barrel-shaped small disk is inserted into the disk rotation guide, or the position at which the disk abuts against the disk rotation stopper means that provides the best gripping of the disk, is somewhat difficult to visually recognize.

In the present invention, at least one, and preferably both, of the insertion start position indicating means indicating the insertion position to the disk rotation guide and the stopper position indicating means indicating the mounting position of the disk rotation stopper means are provided. Therefore, even if the upper and lower eaves-like projections constituting the disk rotation guide are of a very small width, the position at which the barrel-shaped small disk is inserted into the disk rotation guide, or the disk rotation stopper that provides the best clamping of the disk It is easy to see the position where the disk contacts the means.

On the other hand, when playing back a small rectangular disc with an optical disc reproducing apparatus provided with a vertically inserted disc holder, the rectangular small disc is mounted in a central circular empty area surrounded by an annular portion of an adapter. This is the same as the case of the barrel-shaped small disk, but the rectangular small disk is mounted on the rectangular four-sided corner of the rectangular small disk or the rectangular small disk provided on the annular part of the adapter. This is a rectangular small disk fitting area including a rectangular four corners and a cutout part into which the extending plate part is fitted.

Since the rectangular small disk fitting area is formed in a rectangular shape slightly larger than the shape of the rectangular disk, a normal rectangular small disk is fitted in this rectangular small disk fitting area. It can move freely to the extent that the position can be corrected. Therefore, when mounting a rectangular small disk in the rectangular small disk mounting area, first insert two short-side corners of the rectangular small disk into the gap between the corner holding piece and the annular mounting piece, and then Correct the position by returning the rectangular small disk slightly in the long side direction, and insert the other two short-side corners of the rectangular small disk into the gap between the corner holding piece and the annular erection piece.

That is, when the mounting is completed, all four corners are inserted into the gap between the corner holding piece and the annular mounting piece, and the corner holding piece and the annular mounting piece constituting the rectangular small disk holding means are held. At that time, at the same time, the annular ridge piece is configured to surround and surround the hill-shaped projection of the rectangular small disk, so that the hill-shaped projection is closely attached to the annular space formed by the inner edge of the annular ridge piece. It is internally fitted and fixed in position. The procedure for removing the small rectangular disk from the adapter may be reversed.

As described above, the barrel-shaped small disk holding means when the barrel-shaped small disk is mounted in the adapter center circular space, the rectangular small disk holding when the rectangular small disk is mounted in the adapter center circular space. Since both means are formed in the adapter annular portion, the adapter can be detachably attached regardless of whether it is a barrel type or a rectangular type.

[0023]

[Embodiment of the invention]

 An embodiment of the present invention will be described with reference to the drawings.

FIG. 1A is a plan view of the entire embodiment of the present invention, and FIG. 1B is a vertical sectional view of the center line with an enlarged view of the same part. As shown in FIGS. 1A and 1B, in the present embodiment, a rigid synthetic resin material having elasticity such as polypropylene is formed in an annular shape. It has the same diameter as the standard diameter of the popular format compact disc. The diameter of the central circular airspace 2 surrounded by the adapter annular portion 1 is almost the same as the outer diameter of a standard compact optical disc, a so-called single-format optical disc, or more precisely, about a fraction of a millimeter. It is big.

From the inner surface of the thick portion of the adapter annular portion, that is, from the inner edge 2 a of the central circular space 2, several eave-shaped projections are directed toward the center, and the upper and lower surfaces which are the surfaces of the adapter annular portion 1. Extending from the lower surface which is the reproduction surface of These upper and lower eave-shaped protruding pieces, together with the inner edge 2a of the adapter central circular air space, are barrel-shaped small disks 3 of small-sized optical disks having a smaller area than standard-format compact disk optical disks, that is, small-format compact disk standard products. A barrel-shaped small disk holding means for holding a small barrel-shaped disk 3 cut by two parallel lines at a predetermined equidistant distance from the center of the optical disk S, and a disk rotation guide for the small barrel-shaped disk 3 4 is constituted.

With respect to the eave-shaped projections constituting the barrel-shaped small disk holding means or the disk rotation guide 4, the upper eave-shaped projections 5 have a width of about 1 to 2 mm and a center at a symmetrical point. Two locations and lower eave-shaped protrusions are provided at four locations with the center as a symmetrical point. Among them, the first lower eave-shaped protruding pieces 6 formed at two centrally symmetrical positions are formed to be somewhat wider, having a width of 4 to 5 mm, and are components for guiding the insertion into the disk rotation guide 4. The disk mounting projection 7 is configured as follows.

In the embodiment of the present embodiment, the second lower eaves-shaped protruding piece 8 has a width of 1 to 2 mm inside and outside like the upper eaves-shaped protruded piece 5 and has a portion overlapping with the upper eaves-shaped protruded piece 5. Instead, the barrel-shaped small disk 3 is arranged so as to be continuous with the rotation sliding closing surface 9 which is a disk rotation stopper means. The absent portion of the upper eave-shaped protruding piece 5, that is, the cutout portion of the upper eave-shaped protruded piece is a circumferential portion obtained by adding the first lower eave-shaped protruded piece 6 to the circumference 3 a of the barrel-shaped small disk 3. The length of the small disk 3 is longer than the circumference 3a.

When such a small barrel-shaped disk 3 is mounted on the disk mounting projection 7 or the first lower eave-shaped projection 6, the boundary area between the upper eave-shaped projection 5 and the first lower eave-shaped projection 6 is set. Becomes the insertion hole 10 into the disk rotation plan 4. When mounting the disk, the corner 3 b of the barrel-shaped small disk 3 is placed at this position, and the disk is inserted through the disk rotation guide insertion hole 10. Is rotated to slide the barrel-shaped small disk 3 to the rotation sliding closing surface 9 at the stationary position.

The characters START and STOP are respectively positioned at the position of the disk rotation guide insertion hole 10 which is the insertion start position of the disk rotation guide 4 and the position of the rotation sliding closing surface 9 which is the disk rotation stopper position. 11a and 12a are engraved on the adapter annular portion 1 together with the extension lines 11b and 12b at these positions on the barrel-shaped small disk straight side 3c. The START character 11a and the barrel-shaped small disk straight side extended line display 11b at the start of the disk rotation guide insertion opening constitute the insertion start position display means, and the STOP character 12a and the barrel-shaped small disk straight line at the time of rotation sliding stoppage. The side extension line display 12b constitutes a stopper position display means.

Between the first lower eaves-shaped protruding edge 6 and the rotary sliding closing surface 9, a business card size or a rectangular disk 13 slightly larger than the business card size, that is, a small size compact of the barrel-shaped small disk 3. A hill-shaped projection 14 is formed in a thin annular shape at a portion corresponding to the outer diameter standard of the disk, and an extended plate portion 15 is provided at each of the four corners, and a rectangular small disk 13 is fitted. 16 are formed.

The rectangular small disk fitting area 16 is therefore formed in a rectangular shape slightly larger than the rectangular small disk 13, and the width of the first lower eave-shaped protruding edge 6 and the rotary sliding closing surface 9 is set to the short side length. And. The center of the rectangular small disk fitting area 16 is the same as the center of the adapter, and the both end areas are cutouts 1a of the adapter annular portion 1. The cutouts 1a are provided on the front side, that is, on the upper side. The corner holding pieces 17a and 17b are formed on the reproduction surface side, that is, on the lower surface side, and the annular bridging piece 18 is formed integrally with the adapter annular portion 1. The corner holding pieces 17a and 17b and the annular bridging piece 18 constitute a rectangular small disk holding means.

As shown in FIG. 1A, each of the corner holding pieces 17a and 17b is shaped like a sharpened trapezoidal claw and has a large corner holding formed at both ends of one rectangular short side. The piece 17a has a claw width of about 1 to 2 millimeters longer than the small corner holding pieces 17b formed at both ends of the other rectangular short side, and both of the rectangular corners 15a in the extending plate portion 15 of the small rectangular disk 13 are provided. To d from above the adapter.

The annular bridging piece 18 is provided in the notch 1 a of the adapter annular portion 1, with the inner edge 18 a as a circumferential line between the first lower eave-shaped protruding edge 6 and the rotary sliding closing surface 9. You. When the rectangular small disk 13 is mounted on the adapter, on the reproduction surface side of the rectangular small disk 13, the thin annular hill-shaped projection 14 abuts on the inner edge 18 a of the annular installation piece 18 and is surrounded by the rectangular small disk 13. The small disk extending plate portion 15 is placed and clamped from below.

With the above-described configuration, when playing the small barrel-shaped disk 3 with the optical disk playback apparatus provided with the vertically inserted disk holder, the barrel-shaped small disk 3 is mounted on the adapter center circular space 2. As shown in FIG. 2A, which is a flowchart of the procedure for mounting the barrel-shaped small disk on the adapter of the present embodiment, first, as a first procedure, the corners of the barrel-shaped small disk 3 at two centrally symmetric positions are provided. 3b, the barrel-shaped small disk straight side 3c matches or follows the barrel-shaped small disk straight side extended line display 11b while visually recognizing the ST ART character 11a on the disk mounting protrusion 7 or the first lower eaves-shaped protrusion 6. The first lower eave-shaped projection 6 is guided to the disk rotation guide insertion hole 10 as the insertion guide to the disk rotation guide 4, and the entire area of the barrel-shaped small disk circle periphery 3a is guided by the disk rotation guide. 4

In the second procedure, as shown in FIG. 2B, which is an overall view showing the completion of mounting the barrel-shaped small disk on the adapter of this embodiment, the small barrel-shaped disk 3 is attached to the disk rotation guide 4. The barrel-shaped small disk is moved to the position where the upper and lower eave-shaped protruding pieces of the barrel-shaped small disk circumference 3a are fixed and the degree of fixation is good, that is, up to the rotation sliding closing surface 9, and the STOP character 12a While visually observing the rotation of the barrel-shaped small disk 3 until the barrel-shaped small disk straight side 3c coincides with or follows the extended line display 12b. The portion 3b is brought into contact with the rotary sliding closing surface 9.

When the corner 3 b of the small barrel-shaped disk 3 comes into contact with the rotary sliding closing surface 9, the small barrel-shaped disk 3 becomes the upper and lower eave-shaped projections serving as barrel-shaped small disk holding means. In addition, since it is fixed and supported not only on the rotation sliding closing surface 9 but also on the surface, the degree of clamping and fixing becomes the best. The procedure for dismounting the small barrel-shaped disk from the adapter may be the reverse of such a procedure.

On the other hand, when the rectangular small disk 13 is reproduced by the optical disk reproducing apparatus provided with the vertically inserted disk holder, the rectangular small disk 13 is mounted on the rectangular small disk 13 provided in the adapter annular portion 1. This is the small disk fitting area 16.

The procedure for fitting the rectangular small disk 13 into the rectangular small disk fitting area 16, that is, mounting the rectangular small disk 13 on the adapter center circular empty area 2 is performed by mounting the rectangular small disk 13 on the adapter of this embodiment. As shown in FIG. 3 (a), which is a mounting procedure diagram, first, as a first procedure, the two corners 15a, 15b of one short side 13a of the small rectangular disk 13 are circularly erected with the large corner portion holding piece 17a. Insert it all the way into the gap with the piece 18.

Thereafter, as a second procedure, as shown by an arrow in FIG. 3A, the position of the rectangular small disk 13 is corrected by slightly returning it in the long side direction, and the other short side of the rectangular small disk 13 is corrected. The two corners 15c and 15d of 13b are inserted into the gap between the small corner holding piece 17b and the annular bridge piece 18.

When the mounting of the rectangular small disk 13 is completed, as shown in FIG. 3B, which is an overall view showing the completion of the mounting of the rectangular small disk 13, two short corners 15a, 5b is inserted into the gap between the large corner holding piece and the annular mounting piece 18, and the other two corners 15c and 15d are inserted into the gap between the small corner holding piece and the annular mounting piece 18 to be held. .

At that time, at the same time, the annular projection piece 18 surrounds the hill-shaped projection 14 of the small rectangular disk 13, so that the hill-shaped projection 14 is formed by the inner edge 18 a of the annular ridge-shaped piece 18. As shown in FIG. 3 (b), the disk is closely fitted and internally fixed in the annular air space 19 on the disk reproducing surface side. The procedure for removing the small rectangular disk 13 from the adapter may be reversed.

[0042]

[Effects of the Invention] As described above, according to the adapter for reproducing an optical disk of the present invention, a disk holder that is not compatible with a small-format optical disk that is not a standard product of a popular compact disk, such as a so-called barrel-shaped or rectangular small disk, can be obtained. The provided optical disk reproducing apparatus is also provided with an optical disk reproducing adapter that can reproduce these small disks and that is easily removable.

[Brief description of the drawings]

1A is an overall plan view of an adapter according to an embodiment of the present invention, and FIG. 1B is a vertical sectional view of a center line with an enlarged view of the same part.

FIG. 2A is a view showing a procedure for mounting a barrel-shaped disk on the adapter according to the embodiment of the present invention, and FIG.

FIG. 3A is a view showing a procedure for mounting a rectangular disk on the adapter according to the embodiment of the present invention, and FIG. 3B is an overall view showing a state when the mounting is completed.

FIG. 4 is an overall view when a conventional example is used.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Adapter annular part 1a Adapter annular part cutout part 2 Central circular empty area 2a Central circular empty area inner edge 3 Barrel-shaped small disk 3a Barrel-shaped small disk circular periphery 3b Barrel-shaped small disk corner 3c Barrel-shaped small disk straight side 4 Disk rotation Guide 5 Upper eave-shaped protruding piece 6 First lower eave-shaped protruding piece 7 Disc mounting protruding piece 8 Second lower eave-shaped protruding piece 9 Rotation sliding closing surface 10 Disk rotation guide insertion hole 11a START character 11b Disk rotation guide insertion Bar-shaped small disk straight side extension line display at the start 12a STOP character 12b Bar-shaped small disk straight side extension line display at disk rotation sliding stop 13 Rectangular small disk 13a, b Rectangular small disk short side 14 Thin annular hill Protrusion 15 Extended plate portion 15a-d Rectangular small disk corner 16 Rectangular small disk fitting area 17a Corner large holding piece 17b Corner small holding piece 18 Annular erection piece 18a Inner edge of annular installation piece 19 Annular air area 100 Annular part 101 Central circular air area 102 Leaf spring part L Optical disk wide format compact disk standard outer diameter M Optical disk small format compact disk standard outer diameter S Small format compact disk standard product optical disk s Small size Standard size compact disc edge of optical disc

Claims (6)

[Utility model registration claims] An outer diameter of an annular portion of a rigid synthetic resin material having elasticity is defined as an outer diameter of a standard optical disk, ie, a standard outer diameter of a compact disk, ie, a general-purpose component of an optical disk reproducing apparatus. The outer diameter of the standard circular disc that is compatible with the compact disc standard product optical disc holder, and the central circular air area surrounded by the annular portion is substantially equal to the outer diameter of the small format compact disc standard optical disc, that is, the outer diameter of the small format compact disc standard optical disc. In the optical disc playback adapter, the size of the compact optical disc is the same as that of the standard-size compact disc standard disc, but is smaller than the standard compact disc. Small optical disk is concentric with a barrel-shaped small disk, that is, a small-format compact disk standard optical disk To arrange either a two barrel-shaped small disc has been cut in parallel lines in a predetermined equidistant from the center,
Alternatively, a rectangular small disk, that is, a small small disk of the above-mentioned barrel-shaped small disk, a hill-shaped projection is formed in a thin annular shape at a portion corresponding to the outer diameter edge of the standard compact disk, and an extended plate portion is provided at each of the four corners to form a rectangular small disk. A small disk holding means for holding the small disk edge area, and a small rectangular disk holding means for holding the rectangular small disk edge area together with the adapter. An optical disk reproducing adapter formed on an annular portion. 2. The small disk holding means of a barrel type comprises an inner edge of a central circular hollow area of the adapter and an eave-shaped protruding piece extending in a center direction from the inner edge of the central circular hollow area. 2. The optical disk reproducing adapter according to 1. 3. An annular portion of the adapter is provided with four rectangular corners of a small rectangular disk, or cutouts into which the rectangular four corners and the extension plate are fitted, and a disk fitting area including the cutouts is provided. The rectangular disk is configured to have a rectangular shape slightly larger than the shape of the rectangular disk, the corner holding piece formed in the notch, and the annular erection piece installed in the notch constitute rectangular small disk holding means, 2. The optical disk reproducing adapter according to claim 1, wherein the annular bridging piece surrounds and sandwiches the hill-shaped projection. 4. An upper and lower eaves-like projection which sandwiches a small barrel-shaped disk and constitutes a disk rotation guide together with an inner surface of a thick portion of the adapter annular portion, and an upper eave-like projection of the disk rotation guide is cut out. The part is longer than the circumference of one circle of the barrel-shaped small disk, and at an appropriate position of the disk rotation guide,
3. The adapter for reproducing an optical disk according to claim 2, wherein a disk rotation stopper means is provided. 5. A disk mounting projection, wherein a lower eaves-shaped projection is left at an appropriate position of the upper eaves-shaped projection cutout portion of the disk rotation guide, and the disk mounting projection is moved to the disk rotation guide. 5. The optical disk reproducing adapter according to claim 4, wherein the insertion guide is configured as follows. 6. At least one of insertion start position display means for indicating the insertion position of the disk rotation guide and stopper position display means for indicating the position where the disk rotation stopper means is provided,
6. The optical disk reproducing adapter according to claim 4, wherein the adapter is provided on the adapter annular portion.