JPS6320725A - Controlling method for coincidence of focus between two laser beam heads - Google Patents

Controlling method for coincidence of focus between two laser beam heads

Info

Publication number
JPS6320725A
JPS6320725A JP16400386A JP16400386A JPS6320725A JP S6320725 A JPS6320725 A JP S6320725A JP 16400386 A JP16400386 A JP 16400386A JP 16400386 A JP16400386 A JP 16400386A JP S6320725 A JPS6320725 A JP S6320725A
Authority
JP
Grant status
Application
Patent type
Prior art keywords
focus
light spot
maximum
amplitude
coincidence
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
JP16400386A
Inventor
Noboru Ito
Sadao Mizuno
Yoshinao Taketomi
Original Assignee
Matsushita Electric Ind Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date

Links

Abstract

PURPOSE: To quickly and accurately control the focus matching based on the characteristics of an optical head by controlling the focus coincidence between a recording/reproducing light spot and an erasing light spot by means of the maximum position of a tracking error signal.
CONSTITUTION: When an aperture lens 27 crosses continuously a track groove 43, the recording/reproducing and erasing tracking error signals are produced like waves. Then a periodical signal defining the cross of the groove 43 as a pitch P is obtained. The amplitude A becomes maximum when a focus is coincident with the groove 43 in terms of the relation between the focus and the track error signal. Thus a focusing action is attained by securing the maximum amplitude A. When the coincidence is desired between the focus positions of a recording/reproducing light spot 29 and an erasing light spot 39, the focus control is first carried out so that the amplitude of one of both spots 29 and 39 is set at the maximum value. Then the collimation of the optical system of the other light spot is controlled. In such a case, a condenser lens is moved toward its optical axis and the focus position of the light spot is changed so that the amplitude is maximum.
COPYRIGHT: (C)1988,JPO&Japio
JP16400386A 1986-07-11 1986-07-11 Controlling method for coincidence of focus between two laser beam heads Pending JPS6320725A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP16400386A JPS6320725A (en) 1986-07-11 1986-07-11 Controlling method for coincidence of focus between two laser beam heads

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP16400386A JPS6320725A (en) 1986-07-11 1986-07-11 Controlling method for coincidence of focus between two laser beam heads

Publications (1)

Publication Number Publication Date
JPS6320725A true true JPS6320725A (en) 1988-01-28

Family

ID=15784910

Family Applications (1)

Application Number Title Priority Date Filing Date
JP16400386A Pending JPS6320725A (en) 1986-07-11 1986-07-11 Controlling method for coincidence of focus between two laser beam heads

Country Status (1)

Country Link
JP (1) JPS6320725A (en)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH06239432A (en) * 1993-02-15 1994-08-30 Hirose & Co Ltd Continuous vertical conveyor device
US5513164A (en) * 1992-09-11 1996-04-30 Kabushiki Kaisha Toshiba Optical recording and reproducing apparatus
JPH08108914A (en) * 1994-10-06 1996-04-30 Nippon Tainetsu Kagaku Kogyo Kk Carrying and discharging device using bucket

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5513164A (en) * 1992-09-11 1996-04-30 Kabushiki Kaisha Toshiba Optical recording and reproducing apparatus
JPH06239432A (en) * 1993-02-15 1994-08-30 Hirose & Co Ltd Continuous vertical conveyor device
JPH08108914A (en) * 1994-10-06 1996-04-30 Nippon Tainetsu Kagaku Kogyo Kk Carrying and discharging device using bucket

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