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公开(公告)号：JP2001345676A
公开(公告)日：2001-12-14
申请号：JP2000167428
申请日：2000-06-05
Applicant: SONY CORP
Inventor： UNO YOSHIO , KATO HIDETAKA , ADACHI MINORU , SUNAMI KAZUYA , UMEZAWA ATSUSHI , KITANI TOMOFUMI , YOSHIDA TOMOKO
Abstract: PROBLEM TO BE SOLVED: To solve a problem that a variable range is limited at most to 20 times the fundamental frequency practically because of deterioration in linearity offset of programmable control voltage-cutoff frequency fc over a wide variable range of the cutoff frequency fc in an LPF circuit using a gm amplifier. SOLUTION: A low order, for example three order, LPF 21 in a low range side and a high order, for example seven order, LPF 22 in a high range are provided. These LPF 21 and LPF 22 are switched with a switch 23 according to a discrimination result of kinds of optical disks (CD/DVD). More concretely, the low range LPF 21 is used for an operation mode like CD in a low range not requiring much high emphasis the high range, while the high side LPF 22 is used for an operation mode like DVD in a high range requiring high emphasis in the high range. Then, superior control characteristics over a wide range can be obtained.
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公开(公告)号：JP2001244762A
公开(公告)日：2001-09-07
申请号：JP2000053762
申请日：2000-02-29
Applicant: SONY CORP
Inventor： UNO YOSHIO , UMEZAWA ATSUSHI , ADACHI MINORU , SUNAMI KAZUYA , KATO HIDETAKA , KITANI TOMOFUMI , YOSHIDA TOMOKO
Abstract: PROBLEM TO BE SOLVED: To solve the problem of the conventional signal processing circuit, that has required an exclusive pin for external mount of a capacitor, when that the capacitor cutting off a DC component included in an RF signal is provided as an externally mounted component of a signal-processing IC1. SOLUTION: A circuit, generating an RF signal from two signals Sg, Sh including DC offset components Vdg, Vdh, is provided with differential amplifiers 23, 24 where in-phase differential output terminals (collectors of transistors(TRs) Q11, Q13 and collectors of TRs Q12, Q14) are connected in common, the signals Sg, Sh are respectively given to one of each differential input terminal (each base of TRs Q11, Q13) and a mean value which results from averaging the DC components Vdg, Vdh of the two signals Sg, Sh by an averaging circuit 25 is given to the other of each differential input terminal (each being the base of TRs Q12, Q14) as a reference value to obtain a sum signal (Vag+Vah) of only AC components Vag, Vah of the signals Sg, Sh from at least one of differential output terminals.
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公开(公告)号：JP2001244550A
公开(公告)日：2001-09-07
申请号：JP2000055135
申请日：2000-03-01
Applicant: SONY CORP
Inventor： UMEZAWA ATSUSHI , UNO YOSHIO , SUNAMI KAZUYA , KATO HIDETAKA , KITANI TOMOFUMI , YOSHIDA TOMOKO
Abstract: PROBLEM TO BE SOLVED: To prevent lowering of the life of a semiconductor laser due to its useless light emission which is caused when the semiconductor laser is turned on unconditionally in its initial state of power-on time, and to prevent breakage of the semiconductor laser caused by the flow excessive operating current which used to flow because of preadjustment. SOLUTION: A laser control circuit 20 having a switching portion 23 for on/off-operating the semiconductor laser LD, is provided with a switch control portion 24 for on/off-controlling the switching portion 23. By this control portion 24, the switching portion 23 is prevented from being turned on in an initial state such as power-on time, and emission of the semiconductor laser LD is compulsorily stopped.
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公开(公告)号：JPH08129703A
公开(公告)日：1996-05-21
申请号：JP28915294
申请日：1994-10-28
Applicant: SONY CORP
Inventor： UMEZAWA ATSUSHI
Abstract: PURPOSE: To provide a semiconductor integrated circuit being hardly affected by wiring capacity and prevented in deterioration in a frequency characteristic by incorporating a voltage/current conversion part and a feedback damping loop in the semiconductor integrated circuit including a signal amplifier part. CONSTITUTION: A recording system circuit 10 incorporates a gm amplifier 12 being a voltage/current conversion means, the feedback damping loop 13 in addition to a recording amplifier 1 in the semiconductor integrated circuit 11. The gm amplifier converts a recording signal VREC to a recording current IRECIN, and imparts it to the recording amplifier 1. The feedback damping loop 13 feeds back the recording current IRECOUT to the input side of the recording amplifier 1, and by suppressing peaking of a voltage amplitude due to LC resonance in a head end, the frequency characteristic is made flat. The gm amplifier 12 and the feedback damping loop 13 for obtaining the flat frequency characteristic are incorporated in the same semiconductor integrated circuit 11 as the recording amplifier 1. Thus, the probability that the frequency characteristic is deteriorated due to a main cause of a substrate is reduced.
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公开(公告)号：JP2002123945A
公开(公告)日：2002-04-26
申请号：JP2000314764
申请日：2000-10-16
Applicant: SONY CORP
Inventor： UMEZAWA ATSUSHI , KATO HIDETAKA
Abstract: PROBLEM TO BE SOLVED: To solve the problem of the conventional disk drive that cannot have optimally compensated a deteriorated signal level due to missing of a signal caused by a defect such as a flaw or due to dirt such as a fingerprint in accordance with a reproduction speed of an optical disk when a time constant of an AGC circuit and a cut-off frequency of an HPF(High Pass Filter) are fixed. SOLUTION: When an operation section 17 selects a reproduction mode in the optical disk drive of this invention provided with an RF amplifier section 14 having an AGC circuit 21 and an HPF 22 and reproduction speed information corresponding to the selected reproduction mode is given to the RF amplifier section 14, a control section 24 sets a time constant corresponding to the reproduction speed to the AGC circuit 21 and a cut-off frequency corresponding to the reproduction speed to the HPF 22.
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Patent Agency Ranking
公开(公告)号：JPH08237076A
公开(公告)日：1996-09-13
申请号：JP3956895
申请日：1995-02-28
Applicant: SONY CORP
Inventor： UMEZAWA ATSUSHI , SHIIMOTO TSUNENORI , KADOWAKI HIROKAZU
Abstract: PURPOSE: To provide an active band pass filter in which f0 , Q are both set to be optimum values and the adjustment for the setting is very simple. CONSTITUTION: In the active band pass filter comprising two each gm amplifiers 11, 13 and capacitors 16, 20, a GCA 15 is inserted into the filter to receive a circuit input voltage vi , a GCA 23 is inserted in a feedback path 22 feeding back a circuit output voltage vo to an inverting input of the gm amplifier 13, and each gain K of the GCAs 15, 23 is controlled in common by a 2nd control section 25. Thus, the Q is adjusted independently and the f0 is adjusted independently by controlling each of converted variables r11 , r13 of the gm amplifiers 11, 13 in common by a 1st control section 24.
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公开(公告)号：JP2001244764A
公开(公告)日：2001-09-07
申请号：JP2000053765
申请日：2000-02-29
Applicant: SONY CORP
Inventor： KATO HIDETAKA , UNO YOSHIO , UMEZAWA ATSUSHI , SUNAMI KAZUYA , ADACHI MINORU , KITANI TOMOFUMI , YOSHIDA TOMOKO
Abstract: PROBLEM TO BE SOLVED: To solve the problem of the conventional gain control amplifier that has its frequency characteristic degraded due to the effect of parasitic capacitance provided to a gain control system, when a signal system and the gain control system are separated in a differential amplifier. SOLUTION: A current control circuit 2 is provided with a signal system (common base transistors(TRs) Q3, Q4), that processes a current Δi1 obtained by this differential amplifier 1 and with the control system (common base TRs Q5, Q6) that processes a control current Ix to control the gain, a control current Ix passing through the control system is combined with the current δi1 which passes through the signal system, diodes D1, D2 convent the combined current into a voltage, which is led out as an output voltage Vout through an output circuit 3.
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公开(公告)号：JPH07231235A
公开(公告)日：1995-08-29
申请号：JP4314894
申请日：1994-02-16
Applicant: SONY CORP
Inventor： UMEZAWA ATSUSHI
Abstract: PURPOSE:To extend a leading and a trailing time constants of an output without externally a capacitor having a large capacitance in the lump circuit and the magnetic recording device using the lump circuit. CONSTITUTION:An input current I, to an output stage 17A is remarkably reduced by arranging an output stage 17A comprising plural transistors(TRs) Q6, Q7, Q1 in Darlington connection to the circuit and one terminal of a capacitor 15 having a small capacitance built in an integrated circuit chip is connected to an input terminal of the output stage 17A.
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公开(公告)号：JPH03119813A
公开(公告)日：1991-05-22
申请号：JP25714689
申请日：1989-10-03
Applicant: SONY CORP
Inventor： UMEZAWA ATSUSHI , YAMAGUCHI TSUGIO
Abstract: PURPOSE:To prevent a DC offset voltage from occurring between input and out terminals by supplying the output current of a voltage/current converter to the input electrode of a fourth transistor in a current mirror circuit. CONSTITUTION:The input voltage Vin of the input terminal 4 is also applied to the base of the first transistor Q1 of a differential amplifier 1, and the collector currents of the first transistor Q2 and a second transistor Q go to currents 2/1I2 of the current 2I2 of a constant current source 2 with a feedback circuit 6. And a current I3 that flows out from a point P to an output terminal 7 side goes to (I1-I2), and the output voltage Vo of the output terminal 7 goes to I3.Ro=Vin. At such a case, since the operating currents 12 of the first and second transistors Q1 and Q2 of the differential amplifier 1 are equal with each other, no DC offset voltage due to the fluctuation of the voltage between the base and the emitter of the transistor occurs between the input and output terminals.
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10.发明专利
公开(公告)号：JP2005310329A
公开(公告)日：2005-11-04
申请号：JP2004129380
申请日：2004-04-26
Inventor： SHIOURA KUNIHIRO , MOROTOMI SHIRO , HIDA MINORU , MURAKAMI TOSHIYA , UMEZAWA ATSUSHI
CPC classification number: G11B7/24085 , G11B7/0901 , G11B7/0938 , G11B7/24038
Abstract: PROBLEM TO BE SOLVED: To enable TPP (Top hold Push-Pull) tracking to a bonded two-layered disk and to achieving power saving and circuit scale reduction. SOLUTION: An optical recording medium has a recording layer (a projecting pit recording layer) having projecting pits and a recording layer (a recessed pit recording layer) having recessed pits when viewed from a laser incident surface side as recording layers wherein data are recorded by a pit sequence. The depth of the pits is set in the range of λ/4.5 to λ/6. Thereby push-pull signal of required levels is obtained and tracking error signal is generated by the TPP system. The polarity of the tracking signal is switched according to whether the recording layer is the projecting pit recording layer or the recessed pit recording layer to deal with difference between projecting and recessed pits of respective layers. Thereby, the problem by a DPD (Differential Phase Detection) system is canceled. COPYRIGHT: (C)2006,JPO&NCIPI
Abstract translation: 要解决的问题：使TPP（顶部保持推挽）跟踪到粘合的双层盘，并实现节电和电路规模的缩小。 解决方案：当从激光入射表面侧观察时，光记录介质具有具有突出凹坑的记录层（投影凹坑记录层）和具有凹坑的记录层（凹坑记录层），其中数据 由凹坑序列记录。 凹坑的深度设定在λ/ 4.5〜λ/ 6的范围内。 由此获得所需级别的推挽信号，并且TPP系统产生跟踪误差信号。 根据记录层是投影凹坑记录层还是凹坑记录层来切换跟踪信号的极性，以处理各层的凹坑和凹坑之间的差异。 因此，DPD（差分相位检测）系统的问题被取消。 版权所有（C）2006，JPO＆NCIPI
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