IP Library Granted Patent US 6,934,241
Granted Patent B2
US 6,934,241 · App. 10/644,568 · Granted Aug 23, 2005

Information recording medium

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Quick Facts
Patent No.
US 6,934,241
App. No.
10/644,568
Granted
Aug 23, 2005
Kind
B2
Abstract

An information recording medium wherein an optically detectable information recording medium is comprised of at least a substrate, a recording layer, and a resin layer. The information recording medium has surface roughness Rσ on the surface of the recording layer, which is in contact with the resin layer, under 5 nm. The information recording medium controls the reproduction signal noise, enables highly densified recording.

Claims (24)

1. A reproducing apparatus for an optically detectable information recording medium comprising at least a substrate, a recording layer, and a resin layer,

wherein the surface of said recording layer in contact with said resin layer has a Root Mean Square roughness Rσ of less than 5 nm,

said reproducing apparatus at least comprising:

a turntable for holding said information recording medium;

a motor connected to said turntable for making said turntable move relatively;

a light pickup for converging light on said information recording medium and for receiving reflected light from said information recording medium;

a demodulator for demodulating a signal from said light pickup and for transmitting a demodulated signal to an interface;

a servo controller for generating a focus servo signal to drive said light pickup and a tracking servo signal;

an interface for transmitting said demodulated signal from said demodulator externally; and

a controller for controlling said motor, servo controller, and interface.

2. The reproducing apparatus in accordance with claim 1 , wherein said light pickup is at least composed of an objective lens having a numerical aperture of 0.7 to 0.9 and a photo detector.

3. An optically detectable information recording medium at least comprising:

a substrate;

a recording layer; and

a resin layer,

wherein the surface of said recording layer in contact with said resin layer has a Root Mean Square roughness Rσ of less than 5 nm, and said substrate and said recording layer is in contact with each other, and the surface of said substrate is formed with micro patterns, and said micro patterns further comprise a pit.

4. The information recording medium in accordance with claim 3 , wherein width of said pit is 0.05 μm to 1.0 μm.

5. The information recording medium in accordance with claim 3 , wherein said pit is modulated by a modulation signal through the RLL modulation method.

6. An optically detectable information recording medium at least comprising:

a substrate;

a recording layer; and

a resin layer,

wherein the surface of said recording layer in contact with said resin layer has a Root Mean Square roughness Rσ of less than 5 nm, and said substrate and said recording layer is in contact with each other, and the surface of said substrate is formed with micro patterns, and said micro patterns further comprise a groove and a land.

7. The information recording medium in accordance with claim 6 , wherein width of said groove is 0.05 μm to 1.0 μm.

Assignments (5)
CORRECTIVE ASSIGNMENT TO CORRECT THE REMOVE PATENT NUMBERS 10342096;10671117; 10716375; 10716376;10795407;10795408; AND 10827591 PREVIOUSLY RECORDED AT REEL: 58314 FRAME: 657. ASSIGNOR(S) HEREBY CONFIRMS THE ASSIGNMENT. Recorded Feb 29, 2024
From: RAKUTEN, INC.
To: RAKUTEN GROUP, INC.
Reel/Frame 068066/0103 →
CHANGE OF NAME Recorded Dec 6, 2021
From: RAKUTEN, INC.
To: RAKUTEN GROUP, INC.
Reel/Frame 058314/0657 →
CHANGE OF ADDRESS Recorded Dec 17, 2015
From: RAKUTEN, INC.
To: RAKUTEN, INC.
Reel/Frame 037751/0006 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Nov 12, 2012
From: JVC KENWOOD CORPORATION
To: RAKUTEN, INC.
Reel/Frame 029283/0649 →
MERGER Recorded Nov 1, 2012
From: VICTOR COMPANY OF JAPAN, LTD.
To: JVC KENWOOD CORPORATION
Reel/Frame 029227/0836 →