Sony Corporation

Minoru Inagaki

Toru Aida

Yuichi Aki

Kanji Yokomizo

Yuuichi Aki

Kiyotaka Wakamiya

An apparatus for producing an optical disc which optically records desired information on an optical disc master provided with a signal generating unit for generating information which is to be recorded on the optical disc master; a light emitting unit for modulating the light emitted from the light emitting unit to the optical disc master; a head moving unit for moving relative to the optical disc master a head mounting an optical system; a position detecting unit for detecting the position of the head moving unit with respect to the optical disc master; a recording unit, and a controlling unit for reading a series of the set operating information, comparing the radial information of the optical disc master and the reading from the position detecting unit, and performing the control for irradiating the modulated light in accordance with the signal output from the signal generating unit to the optical disc master.

Apparatus for producing optical disc and method of production thereof

An optical disk master exposure apparatus employs first laser light modulated in accordance with signals to be recorded is irradiated on a resist layer to expose the resist layer in patterns corresponding to the signals to be recorded, and second laser light having a wavelength which is not sensed by the resist layer is irradiated on a predetermined surface of a predetermined member. The thickness of the resist layer is measured based on a change in output amount of the second laser light emitted by a light source, the output light amount of which is controlled so as to maintain a constant amount of second reflected light produced by irradiating the second laser light on the predetermined surface of the predetermined member. Also, the predetermined surface of the predetermined member is tested for possible defects existing thereon based on a change in amount of the second reflected light. In this way, a layer thickness test and a defect test can be conducted during an exposure stage, thereby making it possible to integrate the layer thickness testing stage, the defect testing stage, and the exposure stage into a single stage and accordingly realize an exposure apparatus which is capable of simply performing a mastering procedure at a low cost.

Exposure apparatus with thickness and defect detection

An image developing apparatus using a laser beam source to produce an original plate for producing a master disk of an optical type recording disk such as video disk and the like. A disk base plate 3 formed thereon with an exposed optically sensitive film 2 is rotated while developing solution 6 is supplied on the optical sensitive film 2 to remove the exposed parts of the film. To monitor the development, a laser beam 8 from a laser beam source 7 is irradiated on an exposed portion of the optical sensitive film 2 which is being dissolved and zero and first order diffraction light 9 and 10 are detected by first and second detectors 11 and 12. Light amount control element 13 are provided to maintain constant the detected level of zero order light by controlling the laser, and the first order light is used to detect a stop time for the development. Stabilization of the zero order light eliminates fluctuations from external sources such as dust, mist etc. The incident light may be controlled by the control element 13 either directly if a semiconductor laser is used or by using a modulator in the light path if a gas laser is used. The semiconductor laser may have a short coherence length which reduces fluctuations caused by multiple interference effects within the glass disk base plate 3 whose thickness can vary.

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Kanagawa, Japan

Minoru Inagaki