Hitachi HV-D25 User Manual

Long-Time Store Mode

In case that illumination on the subject is insufficient, just increasing the gain of the camera may cause an increase in noise,

resulting in an unclear image. In such a situation, it is advisable to select the long-time store mode using the external

memory. Thereby, the image can be brighter and clearer according to the stored amount of image. This camera is provided

with two kinds of image store functions (CCD MODE:FLD/FRM in SUB MENU 1). When one of these image store

functions is used, video signal output is delivered from the camera with the timing shown below.

Since the degree of after-image increases for a moving subject because of image storing, it is recommended to use the

image store function when taking a still picture or scene.

CCD line A

Even field

odd field

Field store mode

Ab+

Ac+

Aa+

VD signal

Store charge

on CCD line A

Video signal

Store time: 1/15 s (Example)

WE signal

In the field store mode, both the CCD lines

A and B are read out simultaneously. After

completion of storing, video signal output is
made on the next field. Immediately before

the field on which video signal output is
made, the WE signal is delivered from the

D-SUB connector equipped on the rear

panel.

Even field

CCD line B
CCD line A
CCD line B

Store charge
on CCD line B

CCD line B

Even field

Frame store mode

Store charge
on CCD line B

Video signal

Store time: 1/15 s (Example)

WE signal

In the frame store mode, each of the CCD

lines A and B is read out individually.

Therefore, the vertical resolution is superior.

After completion storing, video signal output

is made between two fields. Immediately

before the field on which video signal output

is made, the WE signal is delivered from the

D-SUB connector equipped on the rear panel.

VD signal

CCD line A

CCD line B

CCD line A

Even field

Odd field

Store charge
on CCD line A