Hub type optical disk and injection molding die for molding its disk substrate

Claim 2

A hub type optical disk (K1) as claimed in Claim 1, wherein the recess (2) has a guide face (2a) for receiving an outer periphery of the hub (3).

Claim 3

A hub type optical disk (K2) as claimed in Claim 1, wherein a side face (2b) of the recess (2) is inclined relative to an axis of the disk substrate (1) such that the thickness of the disk substrate (1) is substantially uniform also at a location of the side face (2b).

Claim 4

A hub type optical disk (K4) comprising: a pair of disk substrates (1) each of which has a center hole (1a), a clamp area (1b) disposed radially outwardly of the center hole (1a) and a data area (1c) disposed radially outwardly of the clamp area (1b); wherein a recess (2) is formed at an inner peripheral portion of one face of each of the disk substrates (1), which includes the clamp area (1b), while a projection (1A) is formed in the clamp area (1b) on the other face of each of the disk substrates (1) such that thickness of each of the disk substrates (1) is substantially uniform at the clamp area (1b) and the data area (1c); and a hub (31) which is engageable with a disk mounting member (105a) of an optical disk apparatus and is secured in the recess (2); the recess (2) having a guide face (2a) for receiving an outer periphery of the hub (31); wherein the disk substrates (1) are attached to each other so as to enclose the hub (31).

Claim 5

An injection molding die for performing injection molding of a disk substrate (1) of a hub type optical disk (K2) by using a stamper (12); the disk substrate (1) having a center hole (1a), a clamp area (1b) disposed radially outwardly of the center hole (1a) and a data area (1c) disposed radially outwardly of the clamp area (1b); wherein a recess (2) is formed at an inner peripheral portion of one face of the disk substrate (1), which includes the clamp area (1b), while a projection (1A) is formed in the clamp area (1b) on the other face of the disk substrate (1) such that thickness of the disk substrate (1) is substantially uniform at the clamp area (1b) and the data area (1c); the injection molding die comprising: a lower die (13) to which the stamper (12) is secured; a clamp (13b) for clamping an inner peripheral portion of the stamper (12) to the lower die (13) such that the clamp (13b) acts also as a die for molding the recess (2); and an upper die (14) in which a portion (16) confronting the clamp (13b) has a shape corresponding to that of the clamp (13b).

Claim 6

An optical disk cartridge comprising: a hub type optical disk (K1) which includes a disk substrate (1) and a hub (3); the disk substrate (1) having a center hole (1a), a clamp area (1b) disposed radially outwardly of the center hole (1a) and a data area (1c) disposed radially outwardly of the clamp area (1b); wherein a recess (2) is formed at an inner peripheral portion of one face of the disk substrate (1), which includes the clamp area (1b), while a projection (1A) is formed in the clamp area (1b) on the other face of the disk substrate (1) such that thickness of the disk substrate (1) is substantially uniform at the clamp area (1b) and the data area (1c); the hub (3) being engageable with a disk mounting member (105a) of an optical disk apparatus and being secured in the recess (2); and a cartridge (4) in which the optical disk (K1) is accommodated such that the other face of the disk substrate (1) is brought into contact, at the projection (1A), with the cartridge (4).

Claim 7

An optical disk cartridge as claimed in Claim 6, wherein the recess (2) has a guide face (2a) for receiving an outer periphery of the hub (3).

Claim 8

An optical disk cartridge as claimed in Claim 6, wherein a side face (2b) of the recess (2) is inclined relative to an axis of the disk substrate (1) such that the thickness of the disk substrate (1) is substantially uniform also at a location of the side face (2b).

Claim 9

An optical disk cartridge comprising: a hub type optical disk (K4) which includes a pair of disk substrates (1) and a hub (31); the disk substrates (1) each having a center hole (1a), a clamp area (1b) disposed radially outwardly of the center hole (1a) and a data area (1c) disposed radially outwardly of the clamp area (1b); wherein a recess (2) is formed at an inner peripheral portion of one face of each of the disk substrates (1), which includes the clamp area (1b), while a projection (1A) is formed in the clamp area (1b) on the other face of each of the disk substrates (1) such that thickness of each of the disk substrates (1) is substantially uniform at the clamp area (1b) and the data area (1c); the hub (31) being engageable with a disk mounting member (105a) of an optical disk apparatus and being secured in the recess (2); the recess (2) having a guide face (2a) for receiving an outer periphery of the hub (31); wherein the disk substrates (1) are attached to each other so as to enclose the hub (31); and a cartridge (4) in which the optical disk (K4) is accommodated such that the other face of each of the disk substrates (1) is brought into contact, at the projection (1A), with the cartridge (4).