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公开(公告)号：DE3855780D1
公开(公告)日：1997-03-13
申请号：DE3855780
申请日：1988-07-25
Applicant: SONY CORP
Inventor： YOSHITOSHI YOU , MATSUMOTO YOSHIYUKI , KUME HIDEHIRO , MITSUMORI KOJI , YAMAMOTO ETSUFUMI , OINOUE HIROSHI
Abstract: An optical pickup device having a semiconductor laser element (5) mounted on a substrate (2), a photo detector (3) formed on the substrate to receive a laser beam emitted from the semi-conductor laser element (2) and an optical element (6) mounted on the substrate to cover the photo detector to branch the direction of optical path of the laser beam. The optical element (6) is adapted to reduce the amount of unwanted stray light from the laser (5) reaching the photo detector (3). The rear face (6f) of the element (6) is coated with light absorption material (14) to substantially prevent said incident light from being reflected into the photo detector (3). The light absorption material (14) is chosen to absorb light of the wavelength(s) emitted by the laser element. The material (14) preferably has the same refractive index as the element (6).
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公开(公告)号：SG50885A1
公开(公告)日：1998-07-20
申请号：SG1997003372
申请日：1997-09-11
Applicant: SONY CORP
Inventor： YAMAMOTO ETSUFUMI , KOBAYASHI YOSHIHIRO
Abstract: A tracking error signal calculation circuit has peak detection multiplication circuits which detect the peaks of the detection signals of left and right regions of a photodiode and multiply a coefficient for detecting the deviation of the beam light with respect to the track of the disc recording medium, subtraction circuits for removing an offset by subtracting these multiplication results from the detection signals, and a subtraction circuit which calculates a difference of the signal obtained by removing the offset (performs push-pull operation) and outputs a tracking error signal. The value of the coefficient can be changed by adding an alignment signal to the detection signal. In order to impart the frequency dependency to this coefficient, the alignment signal is added to the signal through a filter.
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公开(公告)号：DE3884093T2
公开(公告)日：1994-04-21
申请号：DE3884093
申请日：1988-07-25
Applicant: SONY CORP
Inventor： YOSHITOSHI YOU , KUME HIDEHIRO , MATSUMOTO YOSHIYUKI , MITSUMORI KOJI , YAMAMOTO ETSUFUMI , OINOUE HIROSHI
Abstract: A focusing error detecting apparatus having a first photo-detector (7a) of which the light receiving portion is halved to provide first (7a4) and second (7a5) light receiving portions asymmetrical with respect to the center of a beam spot of a bundle of incident laser beams, the first photo-detector (7a) being located in the optical path ahead of the focusing point of the bundle of the incident laser beams, a second photo-detector (7b) of which the light receiving portion is halved to provide first (7b4) and second (7b5) light receiving portions asymmetrical with respect to the center of a beam spot of a bundle of incident laser beams, the second photo-detector (7b) being located in the optical path behind a focussing point of the bundle of the incident laser beams and a calculating circuit (3) for calculating a difference between a difference of detected outputs from the first and second light receiving portions of the first photo-detector and a difference of detected outputs from the first and second light receiving portions of the second photo-detector, thereby to derive a focusing error signal from the output of the calculating circuit (3).
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公开(公告)号：CA2002381A1
公开(公告)日：1990-05-22
申请号：CA2002381
申请日：1989-11-07
Applicant: SONY CORP
Inventor： KUME HIDEHIRO , YAMAMOTO ETSUFUMI , MATSUMOTO YOSHIYUKI
Abstract: An optical pick-up device for a recording and/or reproducing apparatus in which a light beam (31) from a semiconductor laser element (14) is converged by an objective lens (1) and irradiated on recording tracks (tR) of an optical disc (101) and the light reflected by the disc (101) is sensed to read and/or record data signals, includes photosensors (17, 18) each having an insensitive central zone (17b, 18b) and arranged to receive the reflected light to generate tracking error signals (TE). The semiconductor laser element (14) is so arranged that the light beam (31) is projected on the disc (101) so that the meridional plane of the light beam (31) extending orthogonal to the junction plane of semiconductor layers of the semiconductor laser element (14) is at such an angle with respect to a tangential line drawn to one of the recording tracks (tR) of the disc (101) that non-symmetries on both sides of the tangential line as a function of the de-focusing direction of the beam spot are compensated.
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公开(公告)号：HK1010273A1
公开(公告)日：1999-06-17
申请号：HK98111394
申请日：1998-10-21
Applicant: SONY CORP
Inventor： YAMAMOTO ETSUFUMI , OHAYASHI YOSHIHIRO
Abstract: A tracking error signal calculation circuit has peak detection multiplication circuits which detect the peaks of the detection signals of left and right regions of a photodiode and multiply a coefficient for detecting the deviation of the beam light with respect to the track of the disc recording medium, subtraction circuits for removing an offset by subtracting these multiplication results from the detection signals, and a subtraction circuit which calculates a difference of the signal obtained by removing the offset (performs push-pull operation) and outputs a tracking error signal. The value of the coefficient can be changed by adding an alignment signal to the detection signal. In order to impart the frequency dependency to this coefficient, the alignment signal is added to the signal through a filter.
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Patent Agency Ranking
公开(公告)号：HK1007825A1
公开(公告)日：1999-04-23
申请号：HK98107006
申请日：1998-06-26
Applicant: SONY CORP
Inventor： KUME HIDEHIRO , YAMAMOTO ETSUFUMI , MATSUMOTO YOSHIYUKI
Abstract: An optical pick-up device for a recording and/or reproducing apparatus in which a light beam (31) from a semiconductor laser element (14) is converged by an objective lens (1) and irradiated on recording tracks (tR) of an optical disc (101) and the light reflected by the disc (101) is sensed to read and/or record data signals, includes photosensors (17, 18) each having an insensitive central zone (17b, 18b) and arranged to receive the reflected light to generate tracking error signals (TE). The semiconductor laser element (14) is so arranged that the light beam (31) is projected on the disc (101) so that the meridional plane of the light beam (31) extending orthogonal to the junction plane of semiconductor layers of the semiconductor laser element (14) is at such an angle with respect to a tangential line drawn to one of the recording tracks (tR) of the disc (101) that non-symmetries on both sides of the tangential line as a function of the de-focusing direction of the beam spot are compensated.
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公开(公告)号：DE3855780T2
公开(公告)日：1997-06-12
申请号：DE3855780
申请日：1988-07-25
Applicant: SONY CORP
Inventor： YOSHITOSHI YOU , MATSUMOTO YOSHIYUKI , KUME HIDEHIRO , MITSUMORI KOJI , YAMAMOTO ETSUFUMI , OINOUE HIROSHI
Abstract: An optical pickup device having a semiconductor laser element (5) mounted on a substrate (2), a photo detector (3) formed on the substrate to receive a laser beam emitted from the semi-conductor laser element (2) and an optical element (6) mounted on the substrate to cover the photo detector to branch the direction of optical path of the laser beam. The optical element (6) is adapted to reduce the amount of unwanted stray light from the laser (5) reaching the photo detector (3). The rear face (6f) of the element (6) is coated with light absorption material (14) to substantially prevent said incident light from being reflected into the photo detector (3). The light absorption material (14) is chosen to absorb light of the wavelength(s) emitted by the laser element. The material (14) preferably has the same refractive index as the element (6).
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公开(公告)号：DE69117344D1
公开(公告)日：1996-04-04
申请号：DE69117344
申请日：1991-05-15
Applicant: SONY CORP
Inventor： KUME HIDEHIRO , YAMAMOTO ETSUFUMI
Abstract: A tracking error signal generator for producing a tracking error signal by first detecting a light beam, which is irradiated from an optical pickup to an optical disc, by an optical detector so divided as to have two optical detecting portions in a direction of a recording track on the optical disc, and then controlling the light beam to follow up the recording track on the optical disc in accordance with the detection outputs from the divided optical detector. The tracking error signal generator comprises first and second peak detecting means for detecting the respective peak values of detection output signals from the first and second optical detecting portions of the optical detector divided along the recording track on the optical disc, and arithmetic means for forming a difference signal between signals obtained by applying a coefficient smaller than 1 to multiply respectively the output signal of the first peak detecting means and the detection output of the first optical detecting portion, and signals obtained by applying a coefficient smaller than 1 to multiply respectively the output signal of the second peak detecting means and the detecting output of the second optical detecting portion.
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公开(公告)号：ID19375A
公开(公告)日：1998-07-02
申请号：ID973165
申请日：1997-09-11
Applicant: SONY CORP
Inventor： YAMAMOTO ETSUFUMI , KOBAYASHI YOSHIHIRO
Abstract: A tracking error signal calculation circuit has peak detection multiplication circuits which detect the peaks of the detection signals of left and right regions of a photodiode and multiply a coefficient for detecting the deviation of the beam light with respect to the track of the disc recording medium, subtraction circuits for removing an offset by subtracting these multiplication results from the detection signals, and a subtraction circuit which calculates a difference of the signal obtained by removing the offset (performs push-pull operation) and outputs a tracking error signal. The value of the coefficient can be changed by adding an alignment signal to the detection signal. In order to impart the frequency dependency to this coefficient, the alignment signal is added to the signal through a filter.
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公开(公告)号：DE3887026T2
公开(公告)日：1994-07-28
申请号：DE3887026
申请日：1988-07-25
Applicant: SONY CORP
Inventor： YOSHITOSHI YOU , MATSUMOTO YOSHIYUKI , KUME HIDEHIRO , MITSUMORI KOJI , YAMAMOTO ETSUFUMI , OINOUE HIROSHI
Abstract: An optical pickup device having a semiconductor laser element (5) mounted on a substrate (2), a photo detector (3) formed on the substrate to receive a laser beam emitted from the semi-conductor laser element (2) and an optical element (6) mounted on the substrate to cover the photo detector to branch the direction of optical path of the laser beam. The optical element (6) is adapted to reduce the amount of unwanted stray light from the laser (5) reaching the photo detector (3). The rear face (6f) of the element (6) is coated with light absorption material (14) to substantially prevent said incident light from being reflected into the photo detector (3). The light absorption material (14) is chosen to absorb light of the wavelength(s) emitted by the laser element. The material (14) preferably has the same refractive index as the element (6).
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