Pioneer PD-4050, Service Manual

Page 1: ...L PATH IN THE PICK UP 8 3 BLOCK DIAGRAM 11 4 CIRCUIT DESCRIPTIONS 13 P I O N E E R E L E C T R O N I C C O R P O R A T I O N 4 1 Meguro 1 Chome Meguro ku Tokyo 153 Japan PIONEER ELECTRONICS SERVICE INC P O Box 1760 Long Beach California 90801 U S A PIONEER ELECTRONICS OF CANADA INC 505 Cochrane Drive Markham Ontario L3R 6B8 Canada TEL 416 479 4411 PIONEER ELECTRONIC EUROPE N V Keetberglaan 1 2740 ...

Page 2: ... B6 B5 B4 B3 B2 B1 NAME REST SCOR Not used TEST ALAT ADAT ACLK SRES XLT Not used Not used CLMP OPEN INSD SENS CPCF GFS Not used I O S I I I I 0 0 0 0 0 0 0 OPERATING DESCRIPTION I GND CPU RESET input RESET RUN I SUBCODE SYNC input SYNC 5V CPU Standby input STAND BY I RUN I Internal Clock Circuit input Internal Clock Circuit input GND for manufacturer s use Connected to SEMS TEST Mode Select input ...

Page 3: ...output ON OFF Muting ON OFF output OFFjON De emphasis ON OFF output QNlQFF During Spindle CLV H H CLV H 5V Main Unit Key Code input LSB Main Unit Key Code input LSB Main Unit Key Code input LSB Main Unit Key Code input LSB Main Unit Key Code input MSB Main Unit Key Strobe input QNlQFF Enable Display Data Send input DISABLElENABLE Display Data Serial Transmission Clock TJTJTJTJLT Display Data Seria...

Page 4: ...23 RAO Vdisp R30 R31 INTO R33 I O 0 0 0 0 0 0 0 0 0 0 0 0 0 i I I I I I 0 I I NAME DSG2 DIGS DIG4 DIG5 DIG6 SEG a SEG b SEG c SEG d SEG e SEG f SEG g SEG h KDO KD1 KD2 KD3 Not used Not used XLT SCOR SENS DESCRIPTION Digital output for FL driving Q N 5 V 26V Digital output for FL driving I Digital output for FL driving f 1 Digital output for FL driving Digital output for FL driving __J TJ Segment o...

Page 5: ...nc Lock input NGlLQCK GND Focus OK input NG OK Laser Diode ON OFF output ONfCHFF Muting ON OFF output QFfJON De emphasis ON OFF output ON OFF CLV H select output OFFfoH 5V Serial clock U U U L T SUBCODE Q Data Serial input Y T QJ7 6 T41 LSI Control Data Serial output oTTT2 3 4 5 J6T7 TEST Mode Select input TEST NORMAL NC NC NC NC NC NC Disc Tray Loading IN IN OUT output BRAKE lOUT Disc Tray OPENed...

Page 6: ... KD4 Not used Not used XEJ SCOR SENS DESCRIPTION I REPEAT LED ON OFF Q N I Q F F NC PROGRAM LED ON OFF QNIQFF Digital output QNIQFF 1 Digital output ON 10FF Segment output for LED ON OFF OV 1 Segment output for LED Segment output for LED Segment output for LED Segment output for LED Segment output for LED Segment output for LED Key Scan input ONlOFF Key Scan input Q N I Q F F Key Scan input ONlOFF...

Page 7: ...nc Lock input NGlLOCK GND Focus OK input NG OK Laser Diode ON OFF output QNlOFF 1 Muting output ON OFF De emphasis ON OFF output ON OFF 1 NC 5 V Serial clock U l f l i l T SUBCODE Q Data Serial input T 1 1 1 1 1 LSI Control Data Serial output o T72 T TJi TEST Mode Select input TEST 1 NORMAL NC NC NC NC NC NC Disc Tray Loading TFT IN OUT output BRAKE OUT Disc Tray OPENed SW input OPEN NOT Disc CLAM...

Page 8: ... 0 order A 1 order Fig 2 2 B 1 Laser diode LD The size of previously used LDs was 90 However a newly developed LD with a size of 5 60 has been introduced This has resulted in a compact and lightweight optical path 2 Objective lens The collimator lens has been replaced by the finite objec tive lens which has a finite convergence distance for the LD s optical path This has resulted in lower costs wh...

Page 9: ...ected beam The RF signal is then produced from this electrical signal by the computation circuit Fig 2 3 shows how the focus signal is detected 1 is when the beam from the laser diode is accurately focused on the disc by the objective lens 2 shows what happens when the disc comes closer to the pickup and 3 shows what hap pens when the disc moves farther away The grating and con cave lens which hav...

Page 10: ... section at the center of the S curve appears as residual error Fig 2 6 shows how the tracking signal is detected The beam from the laser diode is divided into three beams The 1 order beams on either side of the 0 order beam are used to produce the tracking signal These two beams are like the 0 order beam are directed at the disc in a tiny spot In prin ciple the spots of the two side beams are an ...

Page 11: ...tion of RF signals read by the pickup delays have been applied to the output of 2 photodiodes that precede the quarter photodiodes and is followed by an addition operation in order to achieve improvements in frequency responce dis tortion S N and so on as well as to increase the accuracy of signal reading Fig 4 1 1 3 ...

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Page 13: ...re ducing the distortion of RF signals read by the pickup delays have been applied to the output of 2 photodiodes that precede the quarter photodiodes and is followed by an addition operation in order to achieve improvements in frequency responce dis tortion S N and so on as well as to increase the accuracy of signal reading FE Fig 4 1 1 3 1 ...

Page 14: ...y 1 2 kHz in case of 510kn resistance value The height of the focus search operation is approxi mately 1 1 Vp p in case of the time constants shown in the Fig 4 2 This height is in inverse proportion to the value of the resistor connected between Pins 35 and 36 This system is set to a value that is 5 7 of difference between the reference voltage Vcc for the inverted input of the FZC comparator and...

Page 15: ...tage to be applied to the tracking coil at this time is determined by the current value of TM3 or TM4 and the feedback resistor from Pin 18 that is Track Jump Peak Voltage TM3 TM4 current value X feedback resistance TRK coil DCR value X R52 R53 A FWD or REV carriage kick is performed by switching TM5 or TM6 to ON respectively The peak voltage to be applied to the carriage motor at this time is det...

Page 16: ...PF is formed at the built in LPF Pin 23 fc 200 Hz with a 510k 12 resistor thereby eliminating the carrier components of the CLV Servo Error signals MDS and MDP In CLV S Mode FSW goes low and the fc value of the Pin 42 LPF is lowered to further reinforce the filter VCO LOOP FILTER 8 64MHz VCO 1 6 ...

Page 17: ... Dl DO 0 0 0 0 FS4 FS3 FS2 FS1 The four focus related SWs are FS1 to FS4 which respectively correspond to DO to D3 above 00 When FS1 0 Pin 13 is charged to 22 fJLA 11 JUA X 50 ktt 0 55V Moreover if FS2 0 this voltage is trans mitted no further and the output be comes 0 V 02 In the above status only FS2 becomes 1 At this time a negative output is sent from Pin 11 This voltage level is stipulated as...

Page 18: ... focus at this time changes according to Fig 4 8 below The Focus Servo is applied with Point A of Fig 4 8 as its operating point The Focus Search oper ation is performed and the Focus Servo SW is set to ON while Point A of Fig 4 8 is being crossed In order to also prevent malfunction the logical product of the operation and the Focus OK signal is obtained This IC is designed so that FZC Focus Zero...

Page 19: ...ircuit ON OFF ON OFF Brake circuit description These switches are used to switch the Up Normal status of the Tracking Servo gain Because the Servo circuit exceeds the linear range after performing a 100 or 10 track jump the settling of the actuator becomes extremely bad such that it will for example return after jumping only ten tracks although a 100 track jump was intended and such phenomena will...

Page 20: ...equence the TRACK JUMP and FOCS are drawn in Figures a to d show the timing charts of the 1 10 50 or 100 track jump and auto sequence The time control in the figures is done by setting 5X with the system JU COM Auto sequence starts by the sending of 4X in the table below CANCEL FOCUS ON 1 TRACK JAMP 10 TRACK JAMP 100 or 50 TRACK JAMP D3 0 0 1 1 1 D2 0 1 0 0 1 D1 0 1 0 1 0 DO 0 1 X X X X 0 FOWARD X...

Page 21: ...b 10 track jump c 50 track jump 100 2 1 ...

Page 22: ...ltage of about 5 times into a 58k 12 equivalent resistor at the RF I V Amps 1 and 2 Furthermore addition is per formed at the RF Summing Amp so that the output voltage which has been converted from the currents of the photodiodes A B C D is output from Terminal RFC An eye pattern check can be performed at Terminal RFO The low frequency component of the RFO output voltage VRFO is as follows VRPO 1 ...

Page 23: ...g 4 13 TRACKING ERROR AMP Fig 4 14 The voltage of photodiodes for the side spots input to Terminals E and F are respectively subjected to the voltage is increased at the E I V and F I V Amps That is 403k a VF 33k X VP VE 260 kfi X RA RB 22k 12 RA 260kfi 33kO X VPDE Furthermore the output difference between the E I V and F I V Amps is obtained at the Tracking Error Amp in order to obtain the output...

Page 24: ...mp output are obtained at Pin The Focus OK output is inverted in the case below VRF VRFO 0 39 V MIRROR CIRCUIT Fig 4 15 Fig 4 16 After amplifying the RFI signal the Mirror circuit performs Peak Hold and Bottom Hold Peak Hold will hold the peak value at a time constant that is capable of tracking even a 30 kHz Traverse signal whereas Bottom Hold will hold the bottom value at a time constant that is...

Page 25: ...he Mirror output is L upon a disc track or H between disc tracks the Mirror section Moreover the Mirror output is also W when a defect has been detected EFM COMPARATOR Fig 4 18 The EFM Comparator functions to convert the RF the reference voltage of the EFM comparator is signals into binary signals The asymmetry caused controlled by exploiting the respective 50 proba by variance during disc manufac...

Page 26: ...ng and one short The Bottom Hold performed by the short time constant sends a response at a mirror surface defect on the disc that is 0 1 ms or longer The Bottom Hold performed using the long time constant continues holding the mirror surface at the level preceding the defect The Mirror Defect Detection signal is generated by performing a fine plus level shift of that mirror level by use of C coup...

Page 27: ...4a3 TOC READING Initial Settings for Reading of Table of Contents Conditions Carriage is inside and the inside switch S102 is on Loading is completed and loading switch S101 is on 2 7 ...

Page 28: ...he amount required for the carriage movement is ob tained _ Also the carriage s LOCATE operation obtains LOCATE voltage by switching over the internal current source in the serial data This voltage is about 6V However during startup and lock since the output current is limited to 200mA the voltage will become lower than 6V Fig 4 20 Fig 4 21 2 3 ...

Page 29: ...modulation of the EFM data Detection protection and internal extension of the frame sync signal Thorough error detection and correction Interpolation using averaging or previous value hold Demodulation of the sub code and error detection for sub code Q CLV servo for the spindle motor 8 bit tracking counter 9 CPU interface using the serial bus 10 Built in 35th digital filter Fig 4 22 Fig 4 23 ...

Page 30: ...h an 8 bit data of the microcomputer and a 16 bit audio signal from the digital circuit and multiplying both within the attenuator IC it is possible to obtain an audio signal which does not damage the quality of the audio circuit See Fig 4 24 By operating the UP DOWN key of the remote controller every 1 dB of 25 steps 0 dB to 25 dB level adjustment Fig 4 24 Digital level control 3 D ...