Sanyo VPC-E60 Service Manual

Also see for VPC-E60: Instruction manual

Contents

– 5 –1-2. CP1 CIRCUIT DESCRIPTION1. Circuit Description1-1. Digital clampThe optical black section of the CCD extracts averaged val-ues from the subsequent data to make the black level of theCCD output data uniform for each line. The optical black sec-tion of the CCD averaged value for each line is taken as thesum of the value for the previous line multiplied by the coeffi-cient k and the value for the current line multiplied by thecoefficient 1-k.1-2. Signal processor1. γ correction circuitThis circuit performs (gamma) correction in order to maintaina linear relationship between the light input to the cameraand the light output from the picture screen.2. Color generation circuitThis circuit converts the CCD data into RGB signals.3. Matrix circuitThis circuit generates the Y signals, R-Y signals and B-Y sig-nals from the RGB signals.4. Horizontal and vertical aperture circuitThis circuit is used gemerate the aperture signal.1-3. AE/AWB and AF computing circuitThe AE/AWB carries out computation based on a 64-segmentscreen, and the AF carries out computations based on a 6-segment screen.1-4. SDRAM controllerThis circuit outputs address, RAS, CAS and AS data for con-trolling the SDRAM. It also refreshes the SDRAM.1-5. Communication control1. SIOThis is the interface for the 8-bit microprocessor.2. PIO/PWM/SIO for LCD8-bit parallel input and output makes it possible to switch be-tween individual input/output and PWM input/output.1-6. TG/SGTiming generated for 6 million pixel horizontal addtion CCDcontrol.1-7. Digital encorderIt generates chroma signal from color difference signal.2. Outline of OperationWhen the shutter opens, the reset signals (ASIC and CPU)and the serial signals (“take a picture” commands) from the8-bit microprocessor are input and operation starts.When the TG/SG drives the CCD, picture data passes throughthe A/D and CDS, and is then input to the ASIC as 12-bitdata. The AF, AE, AWB, shutter, and AGC value are com-puted from this data, and three exposures are made to obtainthe optimum picture. The data which has already been storedin the SDRAM is read by the CPU and color generation iscarried out. Each pixel is interpolated from the surroundingdata as being either Ye, Cy, Mg or B primary color data toproduce R, G and B data. At this time, correction of the lensdistortion which is a characteristic of wide-angle lenses iscarried out. After AWB and γ processing are carried out, amatrix is generated and aperture correction is carried out forthe Y signal, and the data is then compressed by JPEG andis then written to card memory (SD card).When the data is to be output to an external device, it is takendata from the memory and output via the USB I/F. When playedback on the LCD and monitor, data is transferred from memeryto the SDRAM, and the image is then elongated so that it isdisplayed over the SDRAM display area.3. LCD BlockThe LCD display circuit is located on the CP1 board, andconsists of driver (IC171). The video signals (YCrCb) fromthe ASIC are input as 8-bit digital signals together with thesynchronization control signals (LCDCLK, LCDVD andLCDHD). They are converted to RGB inside the driver andoutput to the LCD panel. Furthermore, the driver has a built-in DC/DC converter to generate the power supplies (8.5 Vand 5.5 V) that are necessary for the LCD.4. Lens drive block4-1. Iris driveWhen the drive signals (IIN1 and IIN2) which are output fromthe ASIC (IC101), iris motor is driven by the driver (IC956),and are then used to drive the iris steps.4-2. Focus driveWhen the drive signals (FIN1, FIN2, FIN3 and FIN4) which areoutput from the ASIC (IC101), the focus stepping motor is drivenby the driver (IC956). Detection of the standard focusing posi-tions is carried out by means of the photointerruptor (FOCUSPI) inside the lens block.4-3. Zoom driveWhen the drive signals (ZIN1, ZIN2, ZIN3 and ZIN4) which areoutput from the ASIC (IC101), the zoom stepping motor is drivenby the driver (IC956). Detection of the standard zoom posi-tions is carried out by means of photointerruptor (ZOOM PI)inside the lens block.4-4. Shutter driveWhen the drive signals (SIN1 and SIN2) which are output fromthe ASIC (IC101), it is driven regular current by the driver(IC956).