Radiant energy – Photocells; circuits and apparatus – Photocell controlled circuit
Reexamination Certificate
1998-07-29
2002-01-15
Lee, John R. (Department: 2878)
Radiant energy
Photocells; circuits and apparatus
Photocell controlled circuit
C348S302000, C348S303000, C257S232000
Reexamination Certificate
active
06339213
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a solid state imaging device and a method for driving the same.
2. Description of the Related Art
As a CCD solid state imaging device, there has been known a CCD solid state imaging device of, for example, a frame interline transfer (FIT) system, a multiple-frame interline transfer (M-FIT) system and so on.
As shown in
FIG. 1
, a CCD solid state imaging device
1
of the frame interline transfer (FIT) system is formed of an imaging section
4
which comprises a plurality of light receiving portions
2
, each serving as a pixel, arranged in a matrix fashion and vertical transfer registers
3
of a CCD structure each corresponding to each column of the light receiving portions
2
, a storage section
6
comprising vertical transfer registers
5
of a similar CCD structure corresponding to the respective vertical transfer registers
3
in the imaging section
4
, a horizontal transfer register
7
adjacent to the storage section
6
, and an output section
8
.
In the CCD solid state imaging device
1
, a signal charge obtained by photoelectric-converting a light in the light receiving portion
2
is read to the vertical transfer register
3
and then once transferred at a high speed (so-called high speed frame shift) to the vertical transfer register
5
in the storage section
6
. Thereafter, the signal charge at every one horizontal line is transferred from the storage section
6
to the horizontal transfer register
7
, transferred within the horizontal transfer register
7
and outputted as a signal from the output section
8
sequentially.
In the CCD solid state imaging device
1
of the FIT system, since a period within which the signal charge resides in the vertical transfer register
3
in the imaging section
4
to which a light may be leaked can be shortened by the frame shift, a smear component charge can be reduced.
As shown in
FIG. 2
, a CCD solid state imaging device
11
of a multiple frame interline transfer (M-FIT) is formed of an imaging section
14
comprising a plurality of light receiving portions
12
, each serving as a pixel, arranged in a matrix fashion and vertical transfer registers
13
of a CCD structure corresponding to columns of the light receiving portions
12
, respectively, a storage section
16
having vertical transfer registers of the CCD structure made of transfer portions with a stage number twice as that of, for example, the vertical transfer registers
13
in the imaging section
14
in correspondence with the vertical transfer register
13
, that is, a first storage section
16
A having vertical transfer registers
15
A made of transfer portions same as the vertical transfer registers
13
in half the stage number and a second storage section
16
B contiguous to the first storage section
16
A and having vertical transfer registers
15
B made of transfer portions same as the former in half the stage number, a horizontal transfer register
17
contiguous to the second storage section
16
B, and an output section
18
.
In the CCD solid state imaging device
11
, within the same vertical blanking period, a signal charge of the light receiving portion
12
on an odd line is transferred first, and then a signal charge of the light receiving portion
12
on an even line is transferred, whereby all the signal charges are transferred.
Specifically, as shown in
FIG. 2
, the signal charge of the light receiving portion
12
on the odd line is read to the vertical transfer register
13
, and then transferred to the vertical transfer register
15
A of the first storage section
16
A at a high speed transfer (high speed frame shift). Next, the signal charge of the light receiving portion
12
on the even line is read to the vertical transfer register
13
, and then transferred to the vertical transfer register
15
A of the first storage section
16
A at a high speed transfer (high speed frame shift) and at the same time, the signal charge of the odd line stored in the first storage section
16
A is transferred to the vertical transfer register
15
B in the second storage section
16
B at a high speed transfer (high speed frame shift).
Thereafter, the signal charge on every one horizontal line is transferred from the storage section
16
(
16
A,
16
B) to the horizontal transfer register
17
, transferred within the horizontal transfer register
17
and sequentially outputted from the output section
18
as a signal.
Then, the signals of all the pixels, that is, the signal on the odd line and the signal on the even line, which are separated and outputted, are rearranged in the original order after they are output from the output section
18
.
According to the CCD solid state imaging device
11
of the M-FIT system, the sensitivity is improved as well as the smear is reduced.
In the CCD solid state imaging device
1
of the FIT system, as described above, the residing period of the signal charge in the vertical transfer register
3
of the imaging section
4
is shortened by the frame shift and then the smear is reduced. However, the smear component charge is generated during the frame shift and hence it is desireable to further reduce the smear. The generation of the smear component charge during the frame shift is directly proportional to the number of pixels in the vertical direction. A large number of vertical pixels may be found in devices such as a high definition television (HDTV).
Recently, although the smear in the CCD solid state imaging device used in a HDTV camera is reduced much, if this smear reduction is compared with that of the CCD solid state imaging device used in a camera for the conventional broadcasting (NTSC), it is still deteriorated by about one digit.
In order that the CCD solid state imaging device is used in both the HDTV camera and one conventional broadcasting camera commonly, the smear is required to be reduced by about one digit as compared with the present smear value.
SUMMARY OF THE INVENTION
In view of the above point, an object of the present invention is to propose a CCD solid state imaging device and its driving method which can reduce smear.
Another object of the present invention is to propose a CCD solid state imaging device which can be applied, in addition to a low smear reading, to a field reading and to an all pixel reading (frame reading) by the M-FIT system and also can be used in a HDTV camera, a conventional broadcasting camera and a movie camera in common.
A CCD solid state imaging device according to the present invention comprises an imaging section formed of a plurality of light receiving portions and vertical transfer registers, first and second storage sections capable of storaging the charge from the imaging section, a horizontal transfer register, and a smear drain region, in which one bit amount of a transfer portion in the vertical transfer register corresponds to two adjacent light receiving portions and the vertical transfer register has a charge storage capacity capable of transferring handling charge amounts of two pixels.
According to the above CCD solid state imaging device, since there are provided the first and second storage sections, the two light receiving portions correspond to one bit amount of the transfer portion in the vertical transfer register of the imaging section, and the vertical transfer register is capable of transferring the handing charge amount of two pixels, a smear component in an interlace mode can be reduced considerably and a so-called low smear reading is made possible.
In other words, after a first smear component charge in the vertical transfer register, which is generated in a light receiving and storage period, is swept away at a high speed, without reading a signal, a signal charge is high-speed transferred (so-called high speed frame shift) first, and a second smear component charge generated during the high speed transfer is finally stored in the second storage section. Then, if the signal charge is read out and then transferred at a high speed (so-called high speed
Lee John R.
Pyo Kevin
Sonnenschein Nath & Rosenthal
Sony Corporation
LandOfFree
Solid state imaging device and method for driving the same does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Solid state imaging device and method for driving the same, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Solid state imaging device and method for driving the same will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2823518