JPH04248146A - Exposing device for optical master disk - Google Patents

Abstract

PURPOSE:To realize a miniaturized and simplified exposing device for master optical disk provided with the lesser number of parts. CONSTITUTION:A laser beam of 840nm wavelength for exposing purpose is emitted from a semiconductor laser 1 and made incident on an optical waveguide shape SHG (2nd hermonic wave generating) element 2 containing a collimating optical system. The beam of 420nm wavelength is emitted as the 2nd hermonic wave by the said SHG element. This beam is converged to the surface of master optical disk on a turntable 14 through a beam rectification optical system 5 and an actuator 12 for objective lens.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical disk master exposure apparatus.

0002

[Prior Art] FIG. 2 is a block diagram of a conventional optical disk master exposure machine, in which 22 is an Ar+ laser (458 nm);
3 is a light amount stabilizing device, 24 is an A/O (Acoustic
Optical (acousto-optic) modulator (for exposure control)
, 25 is a dichroic mirror, 26 is a condensing lens, 2
7 is an A/O modulator (for signal recording), 28 is a mirror, 29
30 is a photodiode for monitoring the amount of light, 30 is a feed drive motor, 31 is a motor control system, 32 is a lens actuator, 33 is a glass substrate, 34 is a turntable, 35 is a laser light source, 36 is a semiconductor laser as a light source, and 37 is a collimator lens. , 38 is a polarizing beam splitter with a λ/4 plate,
39 is a cylindrical lens, 40 is a 4-split pin photodiode, 41 is a focus error detection and servo circuit section, 42 is a beam shaping optical system, 43 is an A/O deflector,
44 is a feed base, and 45 is a preformat signal generation source.

This optical disk master exposure machine includes an A/O deflector 43, a beam shaping optical system 42, a preformat signal generation source 45, an Ar+ laser 22, and a light amount stabilizing device 23.
, A/O modulator 24, dichroic mirror 25, condensing lens 26, and A/O modulator 27 are the parts related to the exposure optical system, and the focus optical system is a semiconductor laser 36 as a light source, as shown by the broken line. , collimator lens 37,
It is composed of a polarizing beam splitter 38 with a λ/4 plate, a cylindrical lens 39, a 4-split pin photodiode 40, and a focus error detection and servo circuit section 41. A focus error detection and servo circuit section 41 controls the lens actuator 32. This method is an astigmatism method. A laser beam for exposure with a wavelength λ=458 nm is emitted from a laser light source (argon ion laser) 22, and a light amount stabilization unit 23 and a dichroic mirror 25 are emitted.
, an A/O (acousto-optic) modulator 2 via a condensing lens 26
7. The exposure beam that has passed through the A/O modulator 27 is directed onto the surface of the optical disc master on the turntable 34 via the A/O (acousto-optic) deflector 43, the beam shaping optical system 42, and the objective lens actuator 32. The light is focused. In this case, a laser light source 22 (wavelength: 458 nm) is used, which has the disadvantage that the device becomes larger and more complicated.

0004

[Object] The present invention has been made in view of the above-mentioned circumstances, and has an object to provide an optical disk master exposure apparatus that has a small number of parts, is compact, and is simple.

[0005]

[Structure] In order to achieve the above object, the present invention includes a laser light source that emits an exposure laser beam, a beam shaping optical system that shapes the exposure beam from the laser light source, and a beam shaping optical system that shapes the exposure beam from the laser light source. An exposure optical system configured to focus a beam onto the surface of an optical disc master, further comprising a second harmonic generation element that receives a laser beam from the laser light source and generates a second harmonic. This is what I did. Hereinafter, the present invention will be explained based on examples.

FIG. 1 is a block diagram for explaining an embodiment of an optical disk master exposure apparatus according to the present invention. In the figure, 1 is a semiconductor laser (840 nm), 2 is an optical waveguide type SHG element (second harmonic Generating element: Second Harmon
ic Generation, e.g. LiNbO3),
3 is an A/O (acousto-optic) deflector, 4 is a monitor beam splitter, 5 is a beam shaping optical system, 6 is a semiconductor laser as a light source, 7 is a collimator lens, 8 is a polarizing beam splitter with a λ/4 plate, 9 is a polarizing beam splitter with a λ/4 plate Cylindrical lens, 10 is 4
split pin photodiode, 11 is a focus error detection and servo circuit section, 12 is a lens actuator, 1
3 is a glass substrate, 14 is a turntable, 15 is a laser light source, 16 is a photodiode for monitoring the amount of light, 17 is a semiconductor laser power supply section and a light amount modulation control section, 18 is a preformat signal generation source, 19 is a feed stand, and 20 is a A feed drive motor 21 is a motor control system.

An exposure laser beam having a wavelength λ=840 nm is emitted from a semiconductor laser 1 and is incident on an optical waveguide type SHG element 2 including a collimating optical system. The SHG element 2 is focused as a second harmonic onto the surface of the optical disc master on the turntable 14 via the beam shaping optical system 5 with a wavelength λ=420 nm and the actuator 12 of the objective lens. In this way, it can be seen that the mechanism of the optical system is greatly simplified when compared with the conventional exposure optical system. Therefore, the exposure apparatus can be made smaller.

That is, as the exposure light source of the master exposure machine, an argon ion laser (458 nm) or a He-Cd laser (442 nm) in the wavelength range to which photoresist is highly sensitive is used.
Gas lasers such as m) are generally used conventionally. These gas lasers are generally large devices and cannot perform high-speed direct modulation, so it is necessary to arrange an external A/O or E/O (Electric Optical) element for modulation. SHG elements are considerably smaller than gas lasers, even including the semiconductor laser that is combined with them, and semiconductor lasers are capable of high-speed direct modulation and do not require other elements, so the exposure optics of the equipment is The system is considerably smaller.

[0009]

[Effects] As is clear from the above explanation, according to the present invention, by using an SHG element, a compact semiconductor laser (LD) capable of direct high-speed modulation can be used in an exposure optical system, and a large-scale equipment It becomes possible to downsize and simplify. Also, assembly of the device becomes easier.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram for explaining an embodiment of an optical disk master exposure apparatus according to the present invention.

FIG. 2 is a configuration diagram of a conventional optical disc master exposure machine.

[Explanation of symbols]

1 Semiconductor laser (840 nm) 2 Optical waveguide type SHG element (second harmonic generation element) 3
A/O deflector 4 Monitoring beam splitter 5 Beam shaping optical system 6 Light source semiconductor laser 7 Collimator lens 8 Polarizing beam splitter with λ/4 plate 9 Cylindrical lens 10 Quadrant pin photodiode 11 Focus error detection and servo circuit section 12
Lens actuator 13 Glass substrate 14 Turntable 15 Laser light source 16 Light intensity monitoring photodiode 17 Semiconductor laser power supply section and light intensity modulation control section 18 Preformat signal generation source 19 Feeding base 20 Feeding drive motor 21 Motor control system

Claims (1)

[Claims] 1. A laser light source that emits an exposure laser beam, a beam shaping optical system that shapes the exposure beam from the laser light source, and a beam shaping system that focuses the beam from the beam shaping optical system onto the surface of an optical disk master. An optical disk master exposure apparatus characterized in that the exposure optical system is provided with a second harmonic generation element that receives a laser beam from the laser light source and generates a second harmonic.