Constant angular velocity disk label printing

Abstract

A visible light characteristic changing layer is formed in a location which can be viewed from a part of a label surface of an optical medium. The optical medium is set on a turntable of an optical disk unit, which may be rotated at a constant angular velocity, while the power of a laser beam is modulated in accordance with image data. The optical pickup operates at a first power level when changing a visible light characteristic of the optical medium to form the visible information and the optical pickup operates at a lower power level when not changing a visible light characteristic of the optical medium. As a result, a visible-light reflectivity of the visible light characteristic changing layer is changed, thereby forming a image corresponding to the image data on the label surface. A tracking servo operation is turned off while the optical pickup forms the visible information.

Description

CROSS REFERENCE TO RELATED APPLICATION [0001] This application is a continuation of application Ser. No. 11 / 210,902, filed Aug. 25, 2005, which is a continuation of application Ser. No. 10 / 053,238, filed Oct. 29, 2001, the entire disclosure of these applications is herein expressly incorporated by reference.BACKGROUND OF THE INVENTION [0002] The present invention relates to a method of printing a label provided on an optical disk, to an optical disk unit, and relates to an optical disk in which a label can be subjected to printing by utilization of a laser beam output from an optical disk unit. [0003] In a recordable optical disk, information about contents recorded thereon (e.g., titles) is described on an optical disk by a user so that the recorded contents can be checked visually. In the case of a single-sided optical disk which is handled as a single disk without being housed in a cartridge, such as a CD-system optical disk i.e., a CD-R (CD recordable), a CD-RW (CD rewritable), ...

AI Technical Summary

Benefits of technology

[0006] The present invention provides a method of forming an image on a label surface of an optical disk, the method comprising the steps of: forming a visible light characteristic changing layer in a position which can be viewed from a label surface side of an optical disk, the layer changing a characteristic of visible light having entered from the label surface side by exposure to a laser beam used for recording a signal and emitted from the part of the label surface; setting the optical disk on a turntable of an optical disk unit such that a label surface of the optical disk is oriented toward a direction in which a laser beam emitted from an optical pickup is to enter; relatively moving the optical disk and the laser beam along a plane of the optical disk; and modulating the laser beam, in synchronism with the mutual movement, into a specific characteristic in accordance with image data to be printed, such as characters or graphic images, and emitting the modulated laser beam onto the visible light characteristic changing layer from the part of the label surface, wherein a reflection characteristic of the visible light having entered the visible light characteristic changing layer is changed by means of exposure, thereby printing a corresponding image on the label surface. According to the label surface image formation method, a laser beam output from the optical disk unit can be emitted onto the visible light characteristic changing layer formed in an area which can be viewed from the part of a label surface of an optical disk, thereby changing the reflectivity, permeability, or light-scattering characteristic of the visible light. In this way, corresponding images, such as characters or graphic images, can be formed on the label surface, thereby obviating a necessity of writing images with a pen or printing images with a printer.

[0008] The present invention also provides an optical disk unit comprising: a relative movement mechanism for relatively moving an optical disk set on a turntable while a label surface is oriented in a direction in which a laser beam is to enter, and a laser beam emitted from an optical pickup along a plane of the optical disk; a laser modulation circuit for modulating a laser beam emitted from the optical pickup; and a circuit for controlling the relative movement mechanism and the laser modulation circuit, wherein the control circuit performs control operation so as to form an image on a visible light characteristic changing layer by controlling the relative movement mechanism to relatively move the optical disk and the laser beam and controlling the laser modulation circuit in accordance with image data, such as characters or graphic images, to be formed on a label surface of the optical disk, thereby modulating a laser beam output from the optical pickup on the basis of the image data, and thereby forming an image corresponding to the image data on the visible light characteristic changing layer, a characteristic of reflectivity, permeability or light scattering of the visible light is changed by the exposure of the laser beam, which can be viewed from the part of a label surface of the optical disk. The optical disk unit enables implementation of the label surface image formation method according to the present invention.

[0010] The present invention also provides an optical disk comprising a visible light characteristic changing layer which changes a visible characteristic of a visible light by exposure to a laser beam having entered from a label surfaces and which is formed in a location capable of being viewed from the part of the label surface. The optical disk enables implementation of the label surface image formation method according to the present invention. Since the visible light characteristic changing layer is formed integrally on an optical disk, occurrence of vibration caused by mass eccentricity during high-speed rotation, and occurrence of failure caused by exfoliation of a label within a drive can be prevented, as compared with a label pasting method.

Problems solved by technology

According to the method in which contents are written directly on the label surface of the disk, a recording layer is often damaged by a strong writing action effected by use of a stiff pencil.

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