Sanyo VPC SX 560, VPC-SX560E, VPC-SX560EX (1), (2), (3), – 4 –, 6-2.Iris drive, 6-3.Focus drive, 6-1.Shutter drive, 6.Lens drive block, Fig. 1-7.Theory of Signal Extraction Operation

5. Transfer of Electric Charge by the Horizontal CCDThe transfer system for the horizontal CCD emplays a 2-phase drive method.

The electric charges sent to the final stage of the horizontal CCD are transferred to the floating diffusion, as shown in Fig. 1-6. RG is turned on by the timing in (1), and the floating diffusion is charged to the potential of PD. The RG is turned off by the timing in (2). In this condition, the floating diffusion is floated at high impedance. The H1 potential becomes shallow by the timing in (3), and the electric charge now moves to the floating diffusion.

Here, the electric charges are converted into voltages at the rate of V = Q/C by the equivalent capacitance C of the floating diffusion. RG is then turned on again by the timing in (1) when the H1 potential becomes deep.

Thus, the potential of the floating diffusion changes in proportion to the quantity of transferred electric charge, and becomes CCD output after being received by the source follower. The equivalent circuit for the output circuit is shown in Fig. 1-7.

(1)	H1	H2	H1	H2	H1 HOG	RG
								CCD OUT
							PD		(1) (2)	(3)
				Floating diffusion				H1	3.5V
(2)									0V
	H1	H2	H1	H2	H1 HOG	RG			3.5V
								H2
									0V
								CCD OUT
							PD		15.5V
								RG	12V
(3)	H1	H2	H1	H2	H1 HOG	RG				RG pulse peak signal
								CCD OUT
										Black level
								CCD OUT
										Signal voltage

Fig. 1-6. Horizontal Transfer of CCD Imager and Extraction of Signal Voltage

Reset gate pulse 12V Pre-charge drain bias（PD）

Direction of transfer

H Register

Voltage output

Electric charge

Floating diffusion gate is floated at a high impedance.

C is charged equivalently

6.Lens drive block6-1. Shutter drive

The two control signals (SIN1, SIN2) which are output from the ASIC expansion port (IC106) are converted into drive pulses(SOUT1, SOUT2) by the motor drive (IC951), and the shutter is opened and closed by regular current drive.

6-2. Iris drive

The two control signals (IIN1, IIN2) which are output from the ASIC expansion port (IC106) are converted into drive pulses (IOUT1, IOUT2) by the motor drive (IC952), and the iris is opened and closed.

6-3. Focus drive

The focusing motor drive clock (FCLK) which are output from the ASIC makes drive signal (FA1, FA2, FB1 and FB2) from drive drection signal (FCW) by driver (IC951) and is then used to drive the micro stepping motor for focusing motor. Detection of the standard focusing positions is carried out by means of the photointerruptor (FOCUS PI) inside the lens block.

Fig. 1-7. Theory of Signal Extraction Operation

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