U.S. patent application number 11/705478 was filed with the patent office on 2007-06-21 for solid-state imaging apparatus.
Invention is credited to Masami Kidono, Hideaki Yoshida.
Application Number | 20070139404 11/705478 |
Document ID | / |
Family ID | 12143388 |
Filed Date | 2007-06-21 |
United States Patent
Application |
20070139404 |
Kind Code |
A1 |
Kidono; Masami ; et
al. |
June 21, 2007 |
Solid-state imaging apparatus
Abstract
A plurality of pixel sets each of 16 pixels are vertically
provided successively one after another. A vertical transfer path 2
has two groups a and b of transfer electrodes 1a, 1b to 16a, 16b.
Two like sequence transfer electrodes in the two electrode groups
are provided for each of the pixels in each set. Each pixel is
connected via a shift gate 3 to each transfer channel corresponding
to each of the transfer electrodes in the electrode group a. To the
transfer electrodes in the electrode group a, independent
shift/transfer pulse application lead lines 4A are connected for
applying independent gate pulses to the individual shift gates in
addition to transfer pulses. Common lead lines are connected to the
transfer electrodes 2a and 4a, 5a and 7a, 10a, 12a, and 13a and
15a. Transfer pulse application lead lines 4B are connected to the
transfer electrodes in the electrode group b. Thus, a CCD imaging
device is constructed, which is capable of performing a desired
read-out operation by 4-phase driving. The invention realizes a
solid-state imaging device capable of reducing the numbers of lead
lines for shift gate control gate electrodes for charge read-out to
a vertical transfer path and external circuit connection terminals
and is capable of a special read-out, such as a multiple rate
read-out.
Inventors: |
Kidono; Masami; (Tokyo,
JP) ; Yoshida; Hideaki; (Tokyo, JP) |
Correspondence
Address: |
STRAUB & POKOTYLO
620 TINTON AVENUE
BLDG. B, 2ND FLOOR
TINTON FALLS
NJ
07724
US
|
Family ID: |
12143388 |
Appl. No.: |
11/705478 |
Filed: |
February 12, 2007 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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09496374 |
Feb 2, 2000 |
7176911 |
|
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11705478 |
Feb 12, 2007 |
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Current U.S.
Class: |
345/204 ;
257/E27.159; 348/E3.02; 348/E9.01 |
Current CPC
Class: |
H01L 27/14868 20130101;
H04N 5/3728 20130101; H04N 5/23245 20130101; H04N 5/347 20130101;
H04N 9/045 20130101 |
Class at
Publication: |
345/204 |
International
Class: |
G09G 5/00 20060101
G09G005/00 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 2, 1999 |
JP |
024627/1999 |
Claims
1-7. (canceled)
8. A solid-state imaging device comprising: a pixel unit
constituted by a two-dimensional array of pixels for generating
charge in correspondence to received light and accumulating the
charge for a predetermined period of time; a vertical transfer unit
for vertically transferring charge from the pixels in the pixel
unit, a horizontal transfer unit for horizontally transferring
charge from the vertical transfer unit; shift gates each provided
between each pixel and the vertical transfer unit for reading out
the charge in the pixels to the vertical transfer unit, gate
electrodes for controlling the shift gates; and a plurality of lead
lines for connecting the gate electrodes to an external circuit and
a plurality of connection terminals for connecting the gate
electrodes to the external circuit, the gate electrodes being
provided in a predetermined number N of gate electrode groups such
that horizontal line number of the gate electrode groups which are
connected to respective common lead lines belong to each same
residue class of modulo N, N being a predetermined natural number
between 4 and one half the number of pixels in a column, and N also
being the minimum periodic unit of connections from said gate
electrodes having the same modulo N value and belonging to
different gate electrode groups to said connection terminals within
said successive pixel rows, some of the gate electrode groups being
commonly connected (i) so that the connection terminals are less in
number than N, and (ii) to enable the gate electrodes having common
connection terminals to be controlled with different timing from
the timing of non-common connection terminals of the gate electrode
groups, wherein the commonly connected gate electrode groups are
always controlled in the same way in each of all predetermined
read-out modes including selective pixel read-out modes by
selective shift gate driving.
Description
BACKGROUND OF THE INVENTION
[0001] The present invention relates to solid-state imaging
apparatuses capable of special read-out, such as read-out at a
desired magnified rate, and more particularly to a solid-state
imaging apparatus permitting special read-out capable of reducing
the numbers of lead lines and connection electrodes to connect
shift gate control gate electrodes to an external circuit.
[0002] Recently, development of so-called electronic still cameras,
which are electronic imaging apparatuses capable of inputting image
data to multi-media systems, are in force. The electronic still
camera usually uses a solid-state imaging unit, such as a CCD
imaging device, for obtaining images. The image obtained in such
camera is displayed on a liquid crystal panel or like view-finder,
and can also be recorded in a recording medium in response to the
depression of a trigger by the user. It has been demanded to
further improve the image quality and operation control property of
the electronic camera. To meet these demands it is indispensable to
use a CCD imaging device having a large number of pixels and also
that it is possible to real time confirm image of the same view
angle as picked-up image with a view-finder.
[0003] By using a high density pixel CCD imaging element, however,
although the high quality image is obtainable, the rate of reading
out one frame image is reduced, and images which are recognized as
motion picture images can not be displayed on the view-finder.
[0004] To cope with this problem, Japanese Patent Laid-Open No.
10-136244, for instance, proposes line addition read-out, in which
charge of each pixel in a row in an array are added together, or
thin-down read-out, in which pixels in columns are thinned down.
Such read-out permits high rate frame-by-frame read-out of image,
although an image quality sacrifice is inevitable. It is thus made
possible to cope with the motion picture image display problem.
[0005] However, the disclosed line addition or thin-down read-out
method is proposed for non-interlace systems, and no specific
technique of high rate read-out system has been disclosed for any
interlace system.
[0006] FIG. 6 shows a construction which is conceivable in case
where the interlace system is applied to the usual inter-line type
CCD imaging device. This example is of four-phase drive type with a
least recurrence unit of two pixels. For the sake of the brevity,
16 pixels are shown as a set. These sets of pixels are arranged
successively one after another in the vertical direction of
vertical transfer path. In the Figure, reference numerals 1 to 16
within rectangles each designate each pixel 1. A vertical transfer
path 2 has two groups a and b of vertical transfer electrodes 1a,
1b to 16a, 16b. Two like sequence transfer electrodes in the two
electrode groups are provided for each of the pixels in each set.
Each pixel 1 is connected via a shift gate 3 to each transfer
channel in the vertical transfer path 2 corresponding to each of
the transfer electrodes 1a to 16a in the electrode group a. The
vertical transfer electrodes are connected to corresponding ones of
four shift pulse application lead lines 4A, via which 4-phase shift
pulses out of phase by 1/4 cycle with one another are applied. The
4-phase transfer pulses are successively applied to the transfer
electrodes, which are grouped in groups each of four transfer
electrodes, whereby the charge read out via the shift gates to the
vertical transfer path 2 are transferred in one direction. In FIG.
6, reference numeral 5 designates connection electrodes for
connecting the lead lines 4 to an external circuit.
[0007] Of the transfer electrodes in the vertical transfer path 2,
those 1b to 16b in the electrode group b merely serve for the
charge transfer. The transfer electrodes 1a to 16a in the electrode
group a, on the other hand, do not only serve for the charge
transfer, but also serve as common gate pulse application
electrodes for turning on the shift gates 3. Thus, while a charge
transfer operation is caused by application of a normal shift
pulse, when a voltage in excess of a predetermined voltage as a
predetermined timing is selectively applied to predetermined
transfer electrodes in the electrode group a, the shift gates 3
corresponding to the selected transfer electrodes are turned on to
cause the pixel charge read-out to the vertical transfer path
2.
[0008] In the case of the 4-phase drive, four transfer channels of
the vertical transfer path corresponding to 4-frame transfer
electrode unit, for instance, the transfer electrodes 1a, 1b and
2a, 2b, constitutes aunit, so that only charge for only one pixel
can be read out. Thus, the pixels that are involved in the shift
along the vertical transfer path 2 correspond in number to one half
the intrinsic number of vertically arranged pixels. This
corresponds to the scanning in the interlace system.
[0009] In the CCD imaging device of the above interlace system, a
construction as shown in FIG. 7 is conceivable when a high rate (or
multiple rate) read out system or like special drive system is to
be applied. In this example, the transfer electrodes 1b to 16b in
the electrode group b in the vertical transfer path 2 perfectly
have only bearing on the charge transfer, and like the 4-phase
drive interlace system CCD imaging device shown in FIG. 6 they are
connected commonly for every 4-frame transfer electrode unit. The
transfer electrodes 1a to 16a in the electrode group a, on the
other hand, are for special driving, have to let them also function
as shift gate electrodes. The gate pulse should be independently
applied to the gate electrode. Thus, it is necessary to provide
independent gate pulse application lead lines to all the transfer
electrodes 1a to 16a in the electrode group a. However, since in
this case a 16-pixel unit recurrence system is adopted, 16 lead
lines 4A are provided for independent gate pulse pplication to the
transfer electrodes. While two lead ines are basically provided for
the transfer electrodes n the electrode group a, 14 lead lines are
newly provided. In addition, two lead lines 4B are provided for the
transfer electrodes in the electrode group b. Thus, the total
number of lead lines is 18. In FIG. 7, reference numeral 6
designates connection electrodes for connecting the independent
gate pulse application lead lines 4A to an external circuit.
[0010] The above construction of the CCD imaging device with a
successive arrangement of a plurality of pixel groups, in which
independent shift gate pulse application lead lines are provided in
correspondence to the individual pixels in each pixel group for
high rate read-out by appropriately adding together charge of a
desired number of pixels, is also disclosed in, for instance,
Japanese Patent Laid-Open No. 10-150601. However, this case and
also the construction shown in FIG. 7, have a problem that large
numbers of lead lines and external circuit connection electrodes
should be provided in connection with the independent gate pulse
application via the transfer electrodes in correspondence to the
number of pixels in each of the successive pixel groups.
SUMMARY OF THE INVENTION
[0011] The present invention was made for solving the above problem
in the prior art solid-state imaging device, in which the vertical
transfer path is provided with lead lines for independent gate
pulse application to the shift gates to permit read-out drive in
many different read-out modes.
[0012] An object of the present invention is to provide a
solid-state imaging device capable of reducing the numbers of the
lead lines for the gate pulse application to the shift gates and
the external circuit connection terminals and capable of special
read-out such as read-out at a desired multiple rate.
[0013] According to a first aspect of the present invention, there
is provided a solid-state imaging device comprising: a pixel unit
constituted by a two-dimensional array of pixels for generating
charge in correspondence to received light and accumulating the
charge for a predetermined period of time; a vertical transfer unit
for vertically transferring charge from the pixels in the pixel
unit, a horizontal transfer unit for horizontally transferring
charge from the vertical transfer unit; shift gates each provided
between each pixel and the vertical transfer unit for reading out
the charge in the pixels to the vertical transfer unit, gate
electrodes for controlling the shift gates; and a plurality of lead
lines and a plurality of connection terminals for connecting the
gate electrodes to an external circuit, the gate electrodes within
successive pixel rows belonging to each coset of modulo N (N being
a predetermined natural number between 4 and one half the number of
pixels in a column) being combined with N gate electrode groups to
reduce number of the external connection terminals.
[0014] According to a second aspect of the present invention, there
is provided a solid-state imaging device comprising: a pixel unit
constituted by a two-dimensional array of pixels for generating
charge in correspondence to received light and accumulating the
charge for a predetermined period of time; a vertical transfer unit
for vertically transferring charge from the pixels in the pixel
unit, a horizontal transfer unit for horizontally transferring
charge from the vertical transfer unit; shift gates each provided
between each pixel and the vertical transfer unit for reading out
the charge in the pixels to the vertical transfer unit, gate
electrodes for controlling the shift gates; and a plurality of lead
lines and a plurality of connection terminals for connecting the
gate electrodes to an external circuit, the gate control lines
within successive pixel rows belonging to each coset of modulo N (N
being a predetermined natural number between 4 and one half the
number of pixels in a column) being combined with each other so as
to reduce number of the external connection terminals.
[0015] According to a third aspect of the present invention, there
is provided a solid-state imaging device comprising: a pixel unit
constituted by a two-dimensional array of pixels for generating
charge in correspondence to received light and accumulating the
charge for a predetermined period of time; a vertical transfer unit
for vertically transferring charge from the pixels in the pixel
unit, a horizontal transfer unit for horizontally transferring
charge from the vertical transfer unit; shift gates each provided
between each pixel and the vertical transfer unit for reading out
the charge in the pixels to the vertical transfer unit, gate
electrodes for controlling the shift gates; and a plurality of lead
lines and a plurality of connection terminals for connecting the
gate electrodes to an external circuit, the gate electrodes being
provided in a predetermined number N (N being a predetermined
natural number between 4 and one half the number of pixels in a
column) of gate electrode groups such that horizontal line number
of the gate electrode groups which are connected to respective
common lead lines belong to each same residue class of modulo N,
some of the gate electrode groups being commonly connected so that
the connection electrodes are less in number than N.
[0016] The commonly connected gate electrode groups are always
controlled in the same way in each of all predetermined read-out
modes including selective pixel read-out modes by selective shift
gate driving.
[0017] The gate electrode groups controlled in each of all the
predetermined read-out modes are set such as to provide a minimum
number of connection terminals for connecting the gate electrodes
to an external circuit.
[0018] With the common connection of some of the gate electrode
groups, it is possible to realize a solid-state imaging device
capable of reducing the numbers of lead lines and connection
terminals for connecting the gate electrodes to an external circuit
and capable of performing a special read-out, such as a desired
multiple rate read-out.
[0019] Other objects and features will be clarified from the
following description with reference to attached drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] FIG. 1 is a block diagram showing the overall construction
of an electronic camera using a CCD imaging device as an embodiment
of the solid-state imaging device according to the present
invention;
[0021] FIG. 2 is a view showing the arrangement of Bayer array
color filters;
[0022] FIG. 3 is a fragmentary view showing a pixel column in the
CCD imaging device shown in FIG. 1 and a corresponding vertical
transfer path;
[0023] FIG. 4 is a view showing read-out manners in various
read-out modes obtainable with the embodiment of the CCD imaging
device shown in FIG. 3;
[0024] FIG. 5 is a timing chart for describing a read-out operation
in a one-field twice read-out mode without use of any mechanical
shutter in the embodiment shown in FIG. 3;
[0025] FIG. 6 is a fragmentary view showing a pixel column in a
prior art 4-phase drive interlace type CCD imaging device; and
[0026] FIG. 7 is a fragmentary view showing a pixel column in a
prior art CCD imaging device for 16-pixel unit 4-phase drive
multiple rate read-out.
PREFERRED EMBODIMENTS OF THE INVENTION
[0027] Preferred embodiments of the present invention will now be
described with reference to the drawings.
[0028] FIG. 1 is a block diagram showing the overall construction
of an electronic camera using a CCD imaging device as an embodiment
of the slid-state imaging apparatus according to the present
invention.
[0029] Referring to the Figure, reference numeral 11 designates a
single plate color CCD imaging device, which photoelectrically
converts light to an electric signal and has an electronic shutter
function. A scene light flux can be inputted through a lens 12 and
a stop-shutter mechanism 13 to the CCD imaging device 11. The
output of the CCD imaging device 11 is subject to noise removal and
amplification in a pre-processor 14, which includes a correlated
double-sampling circuit and a pre-amplifier. An A/D converter 15
converts the output of the pre-processor 14, inputted as analog
data, to digital data. A camera signal processor 16 processes the
signal from the CCD imaging device as image data. An AF/AE/AWB
detector 17 includes an AF detector for generating AF data for
focus control on the basis of the image signal from the CCD imaging
device 11 prior to the intrinsic photography, an AE detector for
generating AE data for exposure control and an AWB detector for
generating an AWB data for white balance level setting. The AF, AE
and AWB data from the AF/AE/AWB detector 17 are supplied through a
CPU 19 to the lens 12, the stop/shutter mechanism 13 and the camera
signal processor 16, respectively.
[0030] A compressor (JPEG) 19 compresses the data quantity. Thus
compressed image data which has been compressed in the compressor
19, is supplied via amemory card interface 24 to a detachably
loaded memory card 25 for recording in the same. A
memory.controller 20 and a DRAM 21 are used as working memories for
the color processing of the image data. A display circuit 22 and a
an LCD display 23 are used for reading out and displaying data
recorded in the memory card 25 for such purposes as confirmation of
the photographing state. A personal computer interface 26 is used
when transferring the data recorded in the memory card 25 to a
personal computer 27. A CCD driver 28 generates a timing pulse or
like signal for driving the CCD imaging device 11 under control of
the CPU 18. A stop/shutter driver 29 drives the stop/shutter
mechanism 12. A strobo mechanism 30 is controlled by the CPU 18
according to the AE data. An input key set 31 sets various read-out
modes of the CCD imaging device, sets various photographing modes,
drives of a trigger switch and so forth.
[0031] The construction of the CCD imaging device 11 will now be
described. The CCD imaging device 11 is an inter-line type device
having a pixel unit constituted by a number of pixels arranged in a
two-dimensional array, and has a Bayer array of color filters. As
shown in FIG. 2, the Bayer array of color filters has R (red) and G
(green) filters arranged alternately in odd lines and G (green) and
B (blue) filters arranged alternately in even lines, whereby the G
(green) filters are in a lattice arrangement as a whole.
[0032] FIG. 3 partly shows a single vertical pixel row and a
vertical transfer path corresponding thereto. Like the CCD imaging
device shown in FIG. 6, this CCD imaging device has a plurality of
pixel groups 1, which are each constituted by 16 pixels in
successive vertical arrangement and are arranged successively
arranged vertically along a vertical transfer path 2. The vertical
transfer path 2 has two groups a and b of transfer electrodes 1a,
1b to 16a, 16b. Two like sequence transfer electrodes in the two
electrode groups a and b are provided for each of the pixels 1 in
each set. Each pixel 1 is connected via a shift gate 2 to each
transfer channel in the vertical transfer path 2 corresponding to
each of the transfer electrodes 12a to 16a in the electrode group a
in the vertical transfer path 2. To the transfer electrodes 1a to
16a of the electrode group a, independent shift/transfer pulse
application lead lines 4A are connected to permit gate pulse
application and also independent gate pulse application to the
shift gates. The respective pixels of the same order in the
successively arranged pixel groups each of 16 pixels, that is, the
line pixel corresponding to each coset of modulo 16, are connected
to an independent shift/transfer pulse application common lead
line. The number of the pixels in each of the successively arranged
pixel groups is usually set to 8, 16, etc., but theoretically it
may be a natural number between 4 and one half the number of pixels
in each column.
[0033] As a feature of the present invention, in this embodiment
one of the independent shift/transfer pulse application lead lines
4A is commonly connected to the transfer electrodes 2a and 4a.
Likewise, the other ones of the independent shift/transfer pulse
application lead lines 4A are commonly connected to the transfer
electrodes 5a and 7a, 10a and 12a, and 13a and 15a, respectively.
With the four common shift/transfer pulse application lead lines
4A, in this embodiment a total of 12 shift/transfer pulse
application lead lines are provided. Of the transfer electrodes in
the vertical transfer path 2, those 1b to 16b in the electrode
group b merely serve for the charge transfer, and two transfer
pulse application lead lines 4B are connected to every 4-th
transfer electrodes, respectively.
[0034] Transfer pulses are applied to the transfer electrodes 1a,
1b to 16a, 16b in a manner as in the construction shown in FIG. 6.
Specifically, 4-phase shift pulses are applied to the two transfer
pulse application lead lines 4B corresponding to the transfer
electrodes 1b to 16b in the electrode group b and also to a
plurality of selected ones of the independent or common
shift/transfer pulse application lead lines 4A for 4-phase driving
as in the CCD imaging device shown in FIG. 6. Also, a special drive
such as a desired high rate (or multiple rate) read-out, is made
possible by appropriately selective gate pulse application to the
independent or common shift/transfer pulse application lead lines
4A.
[0035] A specific example of read-out of data from the CCD imaging
device with the vertical transfer path having independent
shift/transfer pulse application lead lines connected to the
transfer electrode will now be described with reference to FIG. 4.
In the Figure, the numerals in the left and right end columns
denote orders of vertical arrangement of the pixels in one pixel
group, constituted by 16 pixels in successive vertical arrangement.
As for the showing of the read-out and non-read-out pixels in each
read-out mode, every two pixels adjacent to each other in the
horizontal direction of the Bayer array color filters are shown
distinctively. The read-out pixels among the pixels in each
16-pixel set are shown shaded. The channel-like lines striding
specific pixels, shown at the left end, each indicate common
connection of an independent shift/transfer pulse application lead
line to the transfer electrodes in the electrode group a, which
correspond to the pixels shown coupled together by them.
[0036] In the embodiment of the solid-state imaging apparatus, the
conventional interlace type read-out is made for usual high image
quality still picture photographing. Although this read-out is not
described in detail, data of all the pixels are naturally read out
perfectly independently, and thus a high resolution can be
obtained. On the other hand, it is a preamble to use a mechanical
shutter in addition to the electronic shutter for obtaining image
signals of the same accumulation time (or exposure degree) in two,
i.e., odd and even, fields. Hereinunder various special drive
read-out modes different from the full pixel read-out as the usual
inter-lace type read-out will be described.
[0037] First, a double rate addition mode will be described as
read-out mode. In this read-out mode, all the pixels are read out
in two fields to obtain one frame image. The pixels which are read
out in the first field, are shown shaded in an odd field column, as
the timings of read-out of charge to the vertical transfer path
(VCCD), and also the pixels read out in the second field are shown
shaded in the even field column. This read-out is the same as the
conventional inter-lace type read-out except for that at the
instant of charge transfer from the vertical transfer path to the
horizontal transfer path charge in every two read-out pixels are
added together, thus effecting the double rate read-out. In this
case, therefore, it is necessary to use the mechanical shutter in
addition to the electronic shutter for obtaining image signals of
the same accumulation time (or exposure degree) in the two, i.e.,
odd and even, fields.
[0038] A double rate non-addition mode will now be described. In
the case of using the mechanical shutter, the shutter charging for
the next shutter operation requires time. For this reason and also
from the durability standpoint it is impossible to permit
continuous operation. In the double rate non-addition read-out
mode, pseudo non-interlace type read-out is made without use of any
mechanical shutter. With the timings of read-out of charge to the
vertical transfer path (VCCD), one-field image signal is read out
twice, i.e., first read-out (and display) and second read-out (and
display), in such short intervals of time as to hardly affect the
charge storage times of the two read-out pixels, thus obtaining
one-frame image signal.
[0039] Specifically, in the first timing pixel signals of the 2nd
and 4-th pixels and those of the 10-th and 12-th pixels are read
out for obtaining G and B signals, and in the second timing the
pixel signals in the 5-th and 7-th pixels and those of the 13-th
and 15-th pixels are read out in relation to the color filter array
for obtaining R and G signals. These signals are all read out by
transfer pulse application to common shift/transfer pulse
application lead lines.
[0040] In this read-out, the 4-th and 5-th pixels, for instance,
which are adjacent to each other, are read out successively in the
first and second timings, respectively. Therefore, by merely
setting short time interval read-out at the first and second
timings, the pixel charges read out at the first and second times
will be mixed together in the vertical transfer path thus making
their independent transfer impossible. Accordingly, as shown in the
time chart of FIG. 5, in this embodiment after charge of the 2nd,
4-th, 10-th and 12-th pixels have been read out via the shift gates
thereof to the vertical transfer path (VCCD) under control of a
gate pulse signal TG1st at the first timing, a shift pulse is
applied to the vertical transfer path to cause vertical transfer by
one step. Then, charge of the 5-th, 7-th, 13-th and 15-th are read
out via the shift gates thereof to the vertical transfer path under
control of a gate pulse signal TG2nd at the second timing.
[0041] With the provision of one-step vertical charge transfer
between the first and second read-out timings as shown above, the
charge of the 4-th and 5-th pixels are read out with an intervening
one-step charge transfer channel, and are not read out to adjacent
charge transfer channels, and it is thus possible to preclude the
possibility of mixing of read-out charge.
[0042] The read-out charge are successively transferred along the
vertical transfer path, and are added together in operation when
they are transferred from the vertical transfer path to the
horizontal transfer path. However, the pixel signals are read out
such that every other ones of them are thinned out between the
first and second read-out timings. Thus, the vertical transfer is
caused twice in each horizontal blanking period, and a pixel signal
of one of two vertically successive pixels is read out in a
non-addition state as signal charge. In this way, the double rate
non-addition mode read-out is realized.
[0043] Four times rate modes will now be described as read-out
mode, in which 4-pixel addition (or 4-line addition) is performed
by 4-step vertical transfer in the vertical transfer path in one
horizontal blanking period. As the four times rate mode, a 4/16 and
an 8/16 mode exist. In the 4/16 mode, charge of 4 pixels among 16
pixels are read out. More specifically, 4-pixel addition is
performed by 4-step vertical transfer of the charge in one
horizontal blanking period, thus reading out signal charge for one
read-out pixel. At the first timing, signals of the 6-th and 14-th
pixels are read out and, at the second timing, signals of the 1-st
and 9-th pixels are read out. Like the case of the double rate
non-addition mode, one-step vertical transfer is performed between
the first and second read-out timings. After reading out the pixels
at the first and second timings, the 4-pixel addition is performed
by the 4-step vertical transfer of the charge to the horizontal
transfer path in each horizontal blanking period, thus transferring
the signal charge for one read-out pixel to the horizontal transfer
path. In the above way, the four times rate 4/16 mode read-out is
realized.
[0044] The 8-16 mode in four times mode will now be described. In
this mode, charge in 8 among 16 pixels are read out. More
specifically, 4-pixel addition is performed by 4-step vertical
transfer of charge in one horizontal blanking period, thus reading
out signal charge for two read-out pixels. At the first timing
signals of the 2nd and 4-th pixels and those of the 10-th and 12-th
pixels are read out, and at the second timing signals of the 5-th
and 7-th pixels and those of the 13-th and 15-th pixels are read
out. Again in this case, one-step vertical transferis performed
between the first and second read-out timings. After reading out
the pixels at the first and second timings, the 4-pixel addition is
performed by the 4-step vertical transfer of the charge of the
horizontal transfer path in each horizontal blanking period, thus
transferring the signal charge for two pixels to the horizontal
transfer path. In the above way, the four times rate 8-16 read-out
is realized.
[0045] As is seen from the read-out pixel arrangement in the
16-pixel recurrence configuration shown in FIG. 4, the four times
4/16 and 8-16 modes, as well as the double rate addition and
non-addition modes, permit read-out with the read-out pixel
arrangement in the 8-pixel recurrence configuration. Thus, the four
times rate 4/16 and 8/16 modes may also be called four times rate
2/8 and 4/8 modes.
[0046] Eight times rate modes will now be described. The eight
times rate mode is required when taking out the auto-focus data, in
which the image quality is not so important, in a CCD imaging
device of about 4,000,000 pixels for coping with motion picture
purposes such as view angle matching. In the case of the multiple
rate read-out, for taking the color signals it is required, in
relation to color filters, to read out at least 2-line in the case
of the Bayer array and also 2-line read-out among 16 pixels in the
case of the eight times rate read-out.
[0047] First, an eight times 2/16 mode will be described.
[0048] In this mode, 8-pixel addition (or 8-line addition) is
performed by 8-step vertical transfer of the charge to the vertical
transfer path in one horizontal blanking period, thus reading out
signal charge for tow pixels (or two lines). At the first timing,
pixel signal of the first pixel (or 1st line) is read out and at
the second timing, pixel signal of the 8-th pixel (or 8-th line) is
read out. Again in this case, one-step vertical transfer is
performed between the first and second read-out timings. After
reading out the pixels at the first and second timings, 8-pixel
addition (or 8-line addition) is performed by 8-step vertical
transfer of the charge to the horizontal transfer path in each
horizontal blanking period, thus transferring the signal charge for
two pixels (or two lines) to the horizontal transfer path. In this
way, the eight times rate 2/16 read-out is realized.
[0049] This eight times rate read-out mode is principally
realizable by reading out the pixels in the 2nd and 9-th lines for
the 2-line pixel read-out. According to the present invention,
however, it is aimed to provide for common shift/transfer pulse
application lead lines. In the case of reading out the 2nd and 9-th
lines, one of the pixels of the 2nd and 9-th lines is a read-out
pixel, while the other pixel is a non-read-out pixel. In this case,
therefore, it is impossible to provide for common shift/transfer
pulse application lead lines. For this reason, in this embodiment
it is necessary to select the pixels of the 1st and 8-th lines, for
instance, as in the above.
[0050] An eight times rate 4/16 mode will now be described. In this
mode, the 8-pixel addition (or 8-line addition) is performed by
8-step vertical transfer of the charge to the vertical transfer
path in one horizontal blanking period, thus reading out signal
charge for four pixels (or four lines). At the first timing,
signals of the 10-th and 12-th pixels (or lines), are read out and,
at the second timing, signals of the 1st and 3-rd pixels (or lines)
are read out. Again in this step, one-step. vertical transfer is
performed between the 1st and 2nd read-out timings. After reading
out the pixels at the first and second timings, the 8-pixel
addition (or 8-line addition) is performed by the 8-step vertical
transfer of the charge to the horizontal transfer path in each
horizontal blanking period, thus transferring the signal charge for
four pixels or four lines) to the horizontal transfer path. In this
way, the eight times rate 4/16 read-out mode is realized.
[0051] Likewise, in eight times rate 6/16 and 8-16 modes, the
8-pixel addition (or 8-line addition) is performed by the 8-step
vertical transfer of the charge in one horizontal blanking period.
In the 6/18 mode, signals of the 3-rd, 5-th and 7-th pixels are
read out at the first timing, and signals of the 10-th, 12-th and
14-th pixels are read out in the second timing. In the 8/16 mode,
signals of the 10-th, 12-th, 14-th and 16-th pixels are read out at
the first timing, and signals of the 1st, 3-rd, 5-th and 7-th
signals are read out at the second timing. Again in these cases,
one-step vertical transfer is performed between the first and
second read-out timings.
[0052] In the above eight times rate read-out modes, signals read
out from two to eight pixels are added together. Where preference
is given to the sensitivity, he 8/16 mode with large number of
pixels (or lines) in the addition may be selected, while where a
problem is posed by the saturation of transferred charge in the
horizontal transfer path, the 2/16 mode with small number of pixels
involved in the addition may be selected. In this way, the
exemplified various modes of the same multiple rate read-out mode
may be selectively set by taking various circumstances into
considerations.
[0053] As has been shown in the above embodiment, the read-out
modes as shown in FIG. 4 may be obtained by providing for common
shift/transfer pulse application lead lines for the vertical
transfer path. However, the provision of the shift/transfer pulse
application lead lines for the vertical transfer path in the above
embodiment is by no means limitative, and it is possible to set
common lead lines in correspondence to various read-out modes. In
this case, the transfer electrodes to be commonly connected are set
such that the shift/transfer pulse application lead lines are as
small in number as possible.
[0054] As has been described in connection with the above
embodiment, according to the present invention common connection is
provided for some of the gate electrodes, and it is thus possible
to realize a solid-state imaging device capable of reducing the
numbers of lead lines and connection electrodes for connecting the
gate electrodes to an external circuit and capable of performing a
special read-out, such as a desired multiple rate read-out.
[0055] Changes in construction will occur to those skilled in the
art and various apparently different modifications and embodiments
may be made without departing from the scope of the present
invention. The matter set forth in the foregoing description and
accompanying drawings is offered by way of illustration only. It is
therefore intended that the foregoing description be regarded as
illustrative rather than limiting.
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