公开(公告)号：JPH01264087A

公开(公告)日：1989-10-20

申请号：JP9249788

申请日：1988-04-14

Applicant: SHARP KK

Inventor： MASUDA YOSHIFUMI ,  OTSUKA YOSHIHIRO ,  NAGAO HISAO ,  FUKUDA HIROAKI

IPC: H04N9/04 ,  H04N9/73

Abstract: PURPOSE:To easily adjust the amplification factor of a color temperature signal externally without using a variable resistor by obtain a ratio of outputs of two color sensors as an output of an inverse logarithmic transformation device and including an output current of a constant current circuit to the amplification factor of the color temperature signal as a parameter. CONSTITUTION:An inverse logarithmic transformation device 39 receiving the logarithmic value being the result of addition or subtraction of an output of a 3rd logarithmic compression amplifier 33 to/from a difference between outputs of 1st and 2nd logarithmic compression amplifiers 27, 28 as an input signal, converting it into a value corresponding to an anti-logarithm of the input signal and outputting the result and a constant current circuit 38 are provided to the circuit. Thus, as the output of the inverse logarithmic transformation device 39, ratio of outputs of plural color detection elements, that is, a color temperature signal including a color temperature data is obtained and the output current of the constant current circuit 38 is included in the amplification factor of the color temperature signal as a parameter. Thus, the input voltage of the constant current circuit 38 is adjusted externally to vary the output current thereby adjusting the amplification factor of the color temperature signal.

公开(公告)号：JP2002057290A

公开(公告)日：2002-02-22

申请号：JP2000242419

申请日：2000-08-10

Applicant: SHARP KK

Inventor： MASUDA YOSHIFUMI

IPC: H01L27/04 ,  H01L21/822 ,  H01L31/10 ,  H03F3/08 ,  H03K17/78 ,  H04B10/40 ,  H04B10/50 ,  H04B10/60 ,  H04B10/69 ,  H04B10/04 ,  H04B10/06 ,  H04B10/14 ,  H04B10/26 ,  H04B10/28

Abstract: PROBLEM TO BE SOLVED: To provide an optical receiving device of 2-chip configuration where the optical signal is detected with precision with no adjustment for each device. SOLUTION: The optical receiving device of 2-chip configuration comprises a monolithic integrated circuit chip 16 where a trans-impedance amplifier 2 is provided, and a monolithic integrated circuit chip 17 provided with a signal processing circuit 3. Here, a voltage generating means (a constant current circuit 11 and a resistor R3) is provided in the monolithic integrated circuit chip 16 which generates a voltage which is a reference voltage of a signal detecting circuit 5.

公开(公告)号：JPH0453273B2

公开(公告)日：1992-08-26

申请号：JP1887785

申请日：1985-01-31

Applicant: SHARP KK

Inventor： MASUDA YOSHIFUMI ,  TANI YOSHIHEI

IPC: H01L31/12 ,  G01V8/12

公开(公告)号：JPH04129281A

公开(公告)日：1992-04-30

申请号：JP25115490

申请日：1990-09-19

Applicant: SHARP KK

Inventor： MASUDA YOSHIFUMI ,  OTSUKA YOSHIHIRO

IPC: H01L31/12

Abstract: PURPOSE:To delay outputs by a counted number of pulse periods by composing an output delay circuit of an OR circuit for an exclusive OR of the output of a counter for counting a pulse period and the output of a comparator, and an AND circuit for inputting a signal of logic sum of the output of the OR circuit and the output of an oscillator as a clock input signal of the counter. CONSTITUTION:When a photodiode 10 receives a light, the output voltage of an amplifier 11 is raised. When the output of the amplifier 11 exceeds one side input voltage of a comparator 12, i.e., a reference voltage, the output of the comparator 12 becomes from low to high. In this case, if the output of a counter 17 in an output delay circuit 13 maintains low, the output of an OR circuit 18 which inputs an exclusive logic sum of the output of the comparator 12 and the output of the counter 17 becomes high. As a result, the pulse of an oscillator 16 is inputted as a clock input signal of the counter 17 by an AND circuit 19 which inputs a logic sum of the output of the OR circuit 18 and the output of the oscillator 16 as a circuit response having a time delay equal to a counted number of the pulse periods of the oscillator 16.

公开(公告)号：JPH0432307A

公开(公告)日：1992-02-04

申请号：JP13946290

申请日：1990-05-29

Applicant: SHARP KK

Inventor： MASUDA YOSHIFUMI ,  OTSUKA YOSHIHIRO

IPC: H03F3/08 ,  H04B10/00 ,  H04B10/40 ,  H04B10/50 ,  H04B10/60

Abstract: PURPOSE:To keep a dynamic range of an input optical current high even with high sensitivity and to attain miniaturization for monolithic integrated circuit processing by providing a current mirror circuit provided with an integration function an an AC component extraction means. CONSTITUTION:A current mirror circuit ICM 1 provided with an integration function in which a capacitor C2 is connected between an emitter and a base of one transistor(TR) Q4 in place of a differentiating circuit DC as a means extracting only an AC component from an optical current is provided to the AC amplifier. Moreover, two photo TRs FD1, FD2 of the same characteristic are connected to the current mirror circuit ICM 1 attended with the provision of the current mirror circuit ICM 1 to the AC amplifier. Thus, the dynamic range of an input optical current is increased regardless of high sensitivity and even when the cut-off frequency is set low in the case of monolithic integrated circuit processing, since a capacitor with a low capacitance is employed, the miniaturization is attained.

公开(公告)号：JPH10242522A

公开(公告)日：1998-09-11

申请号：JP3946497

申请日：1997-02-24

Applicant: SHARP KK

Inventor： MASUDA YOSHIFUMI ,  FURUTA KOICHI

IPC: H04B10/60 ,  H01L33/00 ,  H04B10/40 ,  H04B10/50 ,  H04B10/556 ,  H04B10/00 ,  H04B10/04 ,  H04B10/06 ,  H04B10/14 ,  H04B10/26 ,  H04B10/28

Abstract: PROBLEM TO BE SOLVED: To reduce a power consumption in the steady state of a circuit for driving the light emitting diode of a communication device which uses an optical fiber as a transmission medium when a current having a peaking at the time of lighting start is applied in order to enable the high speed operation of the light emitting diode. SOLUTION: A current I2 from a constant current supply 13 is turned by a current mirror circuit consisting of transistors Q3 and Q4 to produce a current at the time of steady lighting. At the time of lighting start, a peaking waveform which is generated by a capacitor C in response to the rise of the level of a positive-turn output V3 from a differential amplifier A3 is applied to the base side of the transistor Q4 to superpose the peaking current upon the steady state lighting current. Therefore, a current corresponding to a peaking current value need not be applied consistently but may be applied when the level of the positive-turn output V3 rises only, so that the power consumption can be reduced.

公开(公告)号：JPH09219679A

公开(公告)日：1997-08-19

申请号：JP2420696

申请日：1996-02-09

Applicant: SHARP KK

Inventor： MASUDA YOSHIFUMI

IPC: H04B10/2507 ,  H04B10/07 ,  H04B10/293 ,  H04B10/40 ,  H04B10/50 ,  H04B10/564 ,  H04B10/572 ,  H04B10/60 ,  H04B10/69 ,  H04L25/03 ,  H04B10/02 ,  H04B10/04 ,  H04B10/06 ,  H04B10/14 ,  H04B10/18 ,  H04B10/26 ,  H04B10/28

Abstract: PROBLEM TO BE SOLVED: To enable the optical transmission of a wide band from a high speed transmission to a low speed transmission by suppressing the pulse width distortion of the output signal at the time of the low speed transmission. SOLUTION: In an optical communication system provided with an optical signal transmitter 101 converting the transmission signal transmitted from a terminal into an optical signal at a light emitting element D 11 and transmitting the optical signal, an optical transmission line 102 transmitting the optical signal by an optical fiber cable and an optical signal receiver 103 receiving the optical signal and converting the signal into the transmission signal of a transmission origin, the optical signals transmitted from the optical signal transmitter 101 are converted into electric signals at light receiving elements D 12 and D 13 and voltage amplifications are performed for the converted electric signals in amplifier circuits A 12 and A 13. The peak voltage of the electric signals for which voltage amplifications are performed is generated, the reference voltage proportional to the peak voltage is generated in a reference voltage generation circuit, waveform formings are performed for the electric signals based on the reference voltage and the transmission signal of the transmission origin is reproduced in a signal reproduction circuit. Further, the gain of the amplifier circuits is controlled according to the level of the peak voltage generated in the reference voltage generation circuit.

公开(公告)号：JPH07231307A

公开(公告)日：1995-08-29

申请号：JP2148894

申请日：1994-02-18

Applicant: SHARP KK

Inventor： OTSUKA YOSHIHIRO ,  MASUDA YOSHIFUMI

IPC: H04B10/40 ,  H04B10/07 ,  H04B10/2507 ,  H04B10/50 ,  H04B10/60 ,  H04B10/67 ,  H04B10/69 ,  H04L25/03 ,  H04L25/06 ,  H04B10/28 ,  H04B10/02 ,  H04B10/04 ,  H04B10/06 ,  H04B10/14 ,  H04B10/18 ,  H04B10/26

Abstract: PURPOSE:To provide a light pulse receiving circuit improving the removing characteristic of an in-phase noise caused by a temperature drift or power supply fluctuation by completely making symmetric circuits from an optic/ electric conversion circuit to a comparator for discriminating a pulse level. CONSTITUTION:A pulse signal optoelectric converting a light pulse is connected to one input of a differential amplifier 4, and a reference potential is connected to the other input. Peak values V19 and V20 of respective positive and negative outputs V13 and V14 of the differential amplifier 4 are held by peak value holding circuits 5 and 6. A voltage follower circuit 7 outputs a medium voltage V16 of the positive and negative outputs from the differential amplifier 4. A differential amplifier circuit 8 outputs a center value V23 of the amplitude of V13 from V16, V19 and V20 and applies it to a pulse discriminating comparator 9 as a reference voltage.

公开(公告)号：JPH0750531A

公开(公告)日：1995-02-21

申请号：JP19370293

申请日：1993-08-04

Applicant: SHARP KK

Inventor： OTSUKA YOSHIHIRO ,  MASUDA YOSHIFUMI

IPC: G01R31/28 ,  G05F3/26 ,  H01L21/66 ,  H01L21/822 ,  H01L27/04 ,  H03F3/50

Abstract: PURPOSE:To improve the reliability of the constant voltage circuit as a product in which the constant voltage circuit causing an open fault of a starting resistor in the check stage is surely eliminated. CONSTITUTION:A transistor(TR) Q4 is activated by supplying a current to its base through a resistor R2 to operate a constant current circuit 1 comprising TRs Q2-Q4, diodes D1-D4 and a resistor R1. Then a predetermined bias current is supplied to a base of the TR Q1 being a component of an emitter follower circuit from the constant current circuit 1, which provides an output of a constant voltage. Since a parasitic capacitance C1 is in existence between bases of the TRs Q2, Q3 and ground, a transient current In1 may be supplied through the parasitic capacitance C1 and even when the resistor R2 is in an open fault, the constant voltage circuit is operated. On the other hand, a test pad P1 connecting to a positive feedback loop of the constant current circuit 1 of this constant voltage circuit is used to discriminate whether or not the resistor R2 is in an open fault.

公开(公告)号：JPH0581060B2

公开(公告)日：1993-11-11

申请号：JP22747085

申请日：1985-10-11

Applicant: SHARP KK

Inventor： MASUDA YOSHIFUMI ,  OOTSUKA YOSHIHIRO ,  NAGAO HISAO

IPC: H01L27/06 ,  H01L21/331 ,  H01L21/822 ,  H01L21/8222 ,  H01L27/04 ,  H01L29/72 ,  H01L29/73 ,  H01L29/732 ,  H01L31/10