Pioneer-PD4050-cd-sm2电路图 维修手册.pdf

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1、 FF Remote-Control Code input (MSB) Remote-Control Code input (MSB) Remote-Control Code input (MSB) Remote-Control Code input (MSB) Remote-Control Code input (MSB) Remote-Control Code input (LSB) (NC) (NC) Digital output for FL driving lONl+ 5 m?6w Digital output for FL driving JQN 5 1.3 PD3093A (On

2、ly for PD-4050 and PD-4050-S types) Terminal description No 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 SYMBOL D11 D12 D13 D14 D15 R00 R01 R02 R03 R10 R11 R12 R13 R20 R21 R22 R23 RAO Vdisp R30 R31 INTO R33 I/O 0 0 0 0 0 0 0 0 0 0 0 0 I I I I I I - I 0 I I NAME REPL Not used PGML DIGO

3、 DIG1 SEG.a SEG.b SEG.c SEG.d SEG.e SEG.f SEG.g KDO KD1 KD2 KD3 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 L

4、ED 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 Key Scan input QNlOPF Key Scan input ONlOFF (GND) Buffer power supply GND (GND) LSI Control Data Latch pulse | SUBCODE SYNC S0+S1 inpu

5、t ISYNCI LSI Operating Data Multi-Mode input 6 No 24 2b 26 2/ 28 29 30 31 32 33 34 3b 36 3/ 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 SYMBOL R50 R51 R52 R53 R60 R61 R62 R63 VCC SCK SI SO R43 R70 R71 R72 R73 R80 R81 R82 R83 R90 R91 R92 piT1 Reset TEST OSC1 OSC2

6、GND DO D1 D2 D3 D4 D5 D6 D7 D8 D9 D10 I/O I I I I 0 0 0 0 - 0 I 0 I 0 0 0 0 0 0 0 0 I I I I - - I 0 - s I I I I I I 0 0 0 0 NAME CRCF GFS Not used FOK LDON MUTE DEMP Not used CLK SUBQ DATA TEST Not used Not used Not used Not used Not used Not used LIN LOUT OHEN CLMP TNSD Not used Ms RKD5 RKD4 RKD3 R

7、KD2 RKD1 RKDO Not used Not used PLYL PASL DESCRIPTION I SUBCORD Q-CRC Result input NOfOK 1 Frame Sync 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) +5V Serial clock U l f l i l T SUBCODE Q Data Serial inp

8、ut T1 1 1 1 1 LSI Control Data Serial output oT72|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 CLAMPed SW input CLAMPjNOT Slider Inside SW input INSIDE NOT (GND) CPU Reset input Resetl

9、RUN + 5V Clock Circuit input (Internal Clock Circuit output) GND Remote-Control Key Strobe input IN OFF Remote-Control Key Code input (MSB) Remote-Control Key Code input (MSB) Remote-Control Key Code input (MSB) Remote-Control Key Code input (MSB) Remote-Control Key Code input (MSB) Remote-Control K

10、ey Code input (LSB) (NC) (NC) DLAY-LED ON/OFF QN! 5 V OV PAUSE-LED ON/OFF |5N| 5V Q V 2. OPTICAL !WH IN THE PICK-UP 24 OPTICAL PATH AND OPTICAL PARTS 2-2 FEATURE OF EACH PART DISC Half mirror Objective lens Reflecting mirror Grating (diffraction grating) Laser diode Photo diode (with pre-amplifier)

11、Fig. 2-1 shows the configuration of this pick-ups optical part The wavelength of the light emitted from the laser diode is between 780 and 790 nm. The light is barely visible. This light source is spread into an ellipse from an ultra-small emission point. The light expands at a set angle. The emitte

12、d light goes through a grating and is divided into three beams of 0 step and 1 step. The other beams of 2, 3, and n steps are also present, but are lost and not used. When the light reaches the half mirror, 50% is reflected. The remaining light permeates the half mirror and is lost. The light then g

13、oes to the reflecting mirror where all the light is reflected to the objective lens (finite type). Since this pick-ups objective lens uses a finite system (finite because the LDs convergence distance is finite), a collimator lens is unnecessary. The old models objective lenses are called infinite ty

14、pe. The light that is converged on an ultra-small diameter spot by these objective lenses is reflected by the disc and returns to the objective lens. Then it goes through the half mirror where 50% of it returns to the laser diode. The remaining 50% of light goes through and reaches the photo diode.

15、This has been a general outline of the optical path. The features of each part are explained in the following section. +1 order 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

16、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 LDs optical path. This has resulted in lower costs while preserving high performance. The finite objective l

17、ens, like the conventional infinite lens, is a high-performance lens designed to attain sufficient op- tical performance even when the optical parts are not parallel within the optical path. (3) Half mirror The light that returns to the objective lens goes through the half mirror. Since the half mir

18、ror is a glass plate, it is known that astigmatism is created for the light which enters at an angle. The old model similarly used a glass plate and had a device in its optical part to cancel this astigmatism. Whereas, this new pick-up uses the astigmatism advantage- ously for the focus servo. Conse

19、quently, the multi-lens used in previous models has not been incorporated in this new pick-up. This has resulted in lower costs while preserving high performance. At the same time, the points of parts have been reduced, improv- ing dispersion and reliablity. (4) Axle-sliding actuator The position ac

20、curacy of the objective lens is an important factor for the optical pick-up. The pick-up has a sliding axle for the actuator which drives the objective lens. Accurate and stable positioning of the objective lens is thus attained, resulting in stable trackability. Also, a smooth frequency response wi

21、th low resonance is also realized as with the con- ventional spring-supported type. 8 (5) Resin body The CD body has been made with computer-simulated technology. To keep body changes to a minimum, resin has been incorporated. Due to the mounting, materials were carefully selected and the same relia

22、bility as the previously- used aluminum has been realized. The use of resin has made possible mounting configurations that were not possible with aluminum. Therefore the use of adhesives has been greatly reduced for improved reliability. 2-3 RF and servo signal Fig. 2-3 (2) RF and servo signals The

23、beam, which has been reduced to an extremely small spot by the objective lens, now strikes the disc side on which the signal is. located. Part of the beam is then reflected back to the objective lens and photo diode. A di- agram showing how this beam is reflected off the disc is shown in figure 2-2.

24、 (A) shows what happens when the con- centrated beam is directed at a pit. Normally, this reflected light would disrupt the output light beam. In the laser diodes used in CD players, however, noise is reduced instead, result- ing in stable performance. This property is very advantageous for.the half

25、 prism which allows only half of the light energy to pass. A pit and (B) shows the same beam when reflected from a space between pits. In case (A), the beam is diffracted, so the dark part of the beam does not return to the objective lens. Instead, only the center of the beam passes through the obje

26、ctive lens and reaches the photo diode. In case (B), there is no diffraction because the beam does not strike a pit. There- fore, the entire beam is reflected back to the photo diode, producing brighter beam than when a pit is reached. In this system, the data on the disc, which is represented by pi

27、ts, is covered into an electrical signal at the photo diode accord- ing to the intensity (brightness) of the reflectedbeam. 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 diod

28、e 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 have no direct effect on the focusing are not shown in the diagram. In case (

29、1), the beam emanating from point 01 is reflect- ed and diffracted on the disc surface to produce the con- densed beam (02). In case (2), the beam is directed at a point farther than that of beam 02. Fig. 2-4 shows the properties of the half mirror. 1 through 7 shows the shape of the beam at each po

30、int. Between points 2 and 6, which are in a straight line, the beam is circular at point 4. Point 6 corresponds to beam 02 of fig. 2-3. If we assume that fig. 24 shows mode (1) of fig. 2-3, that means the beam is cir- cular because the photo diode is located at point 4. In mode (2) of fig. 2-3, the

31、location of the photo diode is closer to the cylindrical lens than it was in fig. 2-4. That means the shape of the beam is the same as that of point 3 (an ellipse that has a longer width than height). In mode (3) of fig. 2-3, the shape of the beam is that of point 5, an ellipse that has a longer hei

32、ght than width. Fig. 2-4 Half mirror These beam shapes are shown in fig. 2-3. By perform- ing a (A + C) (B + D) computation using the A-D photo diode quartering elements, the focus signal is produced. Lets consider what happens as the objective lens is gradually moved closer to the disc. If the obje

33、ctive is fair- ly far from the disc, only a small amount of light will be returned to the photo diode. Furthermore, since the return- ing light is quartered, the focus signal would be 0. If the objective lens is moved closer to the disc until point 7 of fig. 24 is reached, the shape of the beam at t

34、he photo diode becomes an ellipse that is higher than it is wide. 9 The focus signal would then be positive because (A + C) is greater than (B + D). However, after the peak (vertical line) is reached at point 6, it begins to return to zero. If it becomes zero at point 4, the beam becomes an ellipse

35、that is wider than it is high because (A + C) is less than (B + D) and the focus signal becomes negative. After peak- ing at point 2, the focus signal returns to zero just as when the objective lens is too far from the disc. Focusing signals produced in the above manner are shown in fig. 2-5. Due to

36、 its shape, this is called an S-curve, an important graph that expresses the properties of the focus signal. Fig, 2-6 Detection of tracking error Fig* 2-5 S-curve Since the real purpose of the focus servo is to maintain the focus signal at zero, only a tiny section at the center of the S-curve appea

37、rs 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

38、 tiny spot. In prin- ciple, the spots of the two side beams are an equal distance from the center spot as shown in fig. 2-6. (The actual dis- tance is much greater than that shown in the figure.) These two side beams are reflected and diffracted and returned to their respective detection elements in

39、 the photo diode. If these two elements detect the same intensity from both beams, it can be assumed that the primary (0 order) beam is correctly following the line of pits on the disc. Fig. 2-7 shows the rela- tionship between the track and the output of each photo di- ode element (A, B and C). Fig

40、. 2-7 Tracking error and the RF signal 10 4. CIRCUIT DESCRIPTIONS 4 . 1 ACCURATE FOCUS SERVO SYSTEM As a method (the Accurate Focus System) for 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

41、 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 i - 1 . 7 0 5 0 . P D - 6 0 5 0 - 5 0 5 0 , P D - 4 0 5 0 4. CIRCUIT DESCRIPTIONS 4 . 1 ACCURATE FOCUS SERVO

42、SYSTEM As a method (the Accurate Focus System) for 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,

43、 dis- tortion, S/N, and so on as well as to increase the accuracy of signal reading. FE Fig. 4-1 13 1 4.2 1C DESCRIPTIONS 4.2.1 CXA1082AS FOCUS SERVO SYSTEM The above figure is a block diagram of the Focus Servo System (Fig. 4-2). When FS3 is ON9 the high-cut filter gain that formed the low-range ti

44、me constant can be dropped by the operation of the capacitor connected between Pins 8 and 9 as well as the internal resistor. The capacitor between Pin 10 and GND is a time constant that boost the low-range frequency during normal play mode. The peak frequency of the Focus Phase Compensator is in in

45、verse proportion to the value of the resistor connected to Pin 239 and its peak value is approxi- mately 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 prop

46、ortion 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 VC (Pin 1); that is9 it is set to (Vcc - VC) X 5.7%. NOTE: When the value of the resistor

47、connected to Pin 23 is changed, changes will also concurrently occur in the peak values of the phase-compensating peak value Focus Servo and Tracking and Carriage Servo systems as well as in the fc value of CVL LPF. In addition, the dynamic range and offset voltage of the OP Amp will also be concurr

48、ently changed. 1 4 TRACKING AND CARRIAGE SERVO SYSTEM The above figure is a block diagram of the Tracking and Carriage Servo System (Fig. 4-3). The capacitor connected between Pins 14 and 15 is a time constant that functions to drop the high-range gain when TG2 is OFF. The peak frequency of the Tracking Phase Compensator is also in reverse pro- portion to the value of the resistor connected to Pin 23, and its peak value is approximately 1.2 kHz in case of 510k 12 resistance value. TM3 or TM4 is