JPS59211384A - Frame transfer type charge transfer imaging device and imaging device using the same - Google Patents

Abstract

PURPOSE:To output a video signal suitable for a conventional television signal form in a still photographing by reading alternately a vertical column of a CCD in an odd number field and an even number field. CONSTITUTION:CCD image pickup cells shown in rectangulars 12 are arranged in an array 10 while being shifted by a half pitch at each vertical column in parallel with the vertical scanning direction shown in the arrow V. Further, clocks phi01 and phi02 of an odd number field are applied only to image pickup cells on the odd number column, e.g., on and on+1. Moreover, clocks phie1 and phie2 of the even number field are applied only to image pickup cells of the even number column, e.g., en and en+1.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a charge transfer imaging device, particularly a frame transfer charge transfer imaging device using a frame transfer charge coupled device (FT-C:CD) as an imaging element, and a charge transfer imaging device using the same. Regarding the photographic device used.

When driving a solid-state imaging device such as the Daiara Koki COD to form a television (TV) signal, what is practically important is whether the TV signal is directly reproduced on a display device, or whether it is played back on a magnetic tape or magnetic disk. The aim is to design the device to be compatible with standard TV signal formats, whether or not it is recorded once on a recording medium with a standard TV signal format. As is well known, L, for example, N
TSC standard color TV system, PAL, SECA
The M TV system also uses a 2-field 1-frame interlaced scanning system.

By the way, in the FT-CCD imaging device, the video signal for one field is transferred from the imaging section of the imaging device to the storage section during the vertical retrace period for each field, and horizontal scanning 1:
A TV signal is formed by sequentially outputting C:D (H-COD) and repeating this for each field. Therefore, for example, when applied to the NTSC system, after the video signal captured in an odd field is transferred to the storage section during the blanking period, the aperture of the imaging cell array is shifted by one scanning line in the next even field to capture the even field. .

Since there is a time difference of 1760 seconds between the two field image information, it is suitable for shooting moving images, that is, movie shooting, but is not suitable for shooting still images, that is, still shooting.

In still photography, image information for one screen, that is, one frame, must be accumulated by one exposure of the imaging cell array. In other words, since there should be no time difference between image information of odd and even fields, conventional FT-CO
It is impossible to directly form a TV signal suitable for such an interlaced scanning method from D.

The present invention solves the drawbacks of the prior art and provides a frame transfer type charge transfer imaging device that can output a video signal compatible with a normal television signal format in still photography, and a frame transfer type charge transfer imaging device using the same. The purpose is to provide the photographic device used in this study.

According to the present invention, there is provided an imaging cell array in which imaging cells are two-dimensionally arranged in horizontal and vertical scanning directions, and an imaging cell array in which imaging cells are arranged along one end of a vertical column of imaging cells in the two-dimensional array. A frame transfer type charge transfer imaging device that outputs an image signal from the water-P transfer path using an interlaced scanning method of two fields per frame, is supplied during one field period in one frame. a first set of electrode means for receiving a first clock signal to transfer pixel signals accumulated in every other vertical column of imaging cells in the imaging cell array to a horizontal transfer path; and the other field in the l frame. a second set of electrode means for receiving a second clock signal supplied during the period and transferring pixel signals accumulated in every other remaining vertical column of imaging cells in the imaging cell array to the horizontal transfer path; , the imaging cell array has a first
The imaging cells are alternately vertically offset in vertical columns such that when a set of electrode means is activated they form one field and when a second set of electrode means is activated they form the other field. It is arranged as follows.

An imaging apparatus using such an imaging device includes a clock signal generation circuit that generates a first clock signal during one field period in an l frame and a second clock signal during the other field period in an l frame; The image pickup cell array includes an exposure means for exposing a subject image for a desired time, whereby a video signal displaying a still image of the subject image exposed for a desired time by the exposure means is output from a horizontal transfer path.

11 and 1'' Next, embodiments of a frame transfer type charge transfer imaging device according to the present invention and an imaging apparatus using the same will be described in detail with reference to the accompanying drawings.

FIG. 1 conceptually shows a pixel arrangement in an embodiment of a frame transfer type charge transfer imaging device according to the present invention. In this CCD, electrodes forming part of a metal oxide semiconductor (MOS) structure are arranged on the main surface of a semiconductor substrate to form an imaging cell array IO, as in a normal CCD. As can be seen from the figure, the array IO has CCD imaging cells, ie, pixels, indicated by a rectangle 12, arranged in eastward columns (for example, odd columns on, on+) parallel to the vertical scanning direction indicated by an arrow V.
1, and even columns en and en+1), they are alternately arranged with a shift of half a pitch, that is, 172 pixels. Note that the structure of the semiconductor substrate and electrodes are not illustrated in order to avoid multiple illustrations.

At the bottom end of each vertical column, a horizontal transfer COD (H-GCD) 14 is arranged parallel to the horizontal scanning direction indicated by arrow H. The H7CCD 14 forms a horizontal transfer path for outputting a video signal for each horizontal scanning line from the imaging cell array 10 to the video signal output terminal 38. This CCD as a whole constitutes a so-called frame transfer type CCD, but it is not provided with a storage section for temporarily storing one frame of video signal like a conventional COD.

In the imaging cell array 10, vertical transfer C0D (V-
C:CD) may be, for example, a two-phase driving force type COD that has a potential gradient depending on the distribution of implanted impurities.

The two-phase clocks φOI and φ02 shown in FIG.
Two-phase clocks φel and φe2 are also supplied to cco from clock terminals 20.24 and 22.26, respectively. These clocks have the same frequency as the horizontal scan of the TV scan. In response to this, the imaging cell array lO
When driven, pixel signals are transferred for each horizontal scanning line, that is, pixel signals are read out.

For example, in the case of the NTSC standard color TV system, interlaced scanning of two fields and one frame is performed. In the odd field, only the clocks φ01 and φ02 of the odd field are supplied with opposite phases to each other as shown in FIG. Form it. For example, as shown in FIG. 2(A), if φe2 is at a high level, the even field pixel signal is φe2
is held in a well. Similarly, in the even field, as shown in (B), the even field clock φe
Only 1 and φe2 are supplied to IJ in reverse phase. Odd field clocks φ01 and φ02 are odd column clocks,
For example, it is supplied only to On and On+1 imaging cells, and even field clocks φe1 and φe2 are supplied only to even-numbered columns, eg, en and en+1 imaging cells. Therefore, in odd fields, only pixel signals in odd columns are transferred to the 11" primary H-CGD I4 for each horizontal row, as shown by arrows 30 in FIG. pixel signals are sequentially transferred to HC:CD+4 for each row.

The pixel signal transferred to the horizontal C0D14 is supplied to the clock terminals 34 and 36, respectively, to the horizontal transfer locks φold and φH2, which are in opposite phases and equal to the pixel signal frequency.
In response to this, the signal is transferred in the H direction and outputted from the video output terminal 38 as a video signal of 1 horizontal scanning line.

In this way, the imaging device of this embodiment directly captures two images from one screen, that is, a frame, captured by the imaging cell array 10.
A video signal of two fields can be formed. Therefore, it is possible to construct a color camera most suitable for methyl photography.

As shown in FIG. 3, a CO equipped with an imaging cell array 10
An optical shutter, that is, an exposure means 54, is disposed at the imaging position of the imaging lens 52, and is disposed between the lens 52 and the array 10 to allow incident light from the subject to enter the array 10 for a necessary exposure time. and constitutes the photographing device. CCD 50 has clock terminals 20.22.24
, 2B, 34 and 3111 (Fig. 1) are the connection wire bundle 56.
It is connected to the drive circuit 58 by. Drive circuit 58
generates odd field transfer locks φO1 and φ02 in odd fields of l frame, and generates locks φe1 and φ1 in even field transfers in even fields.
e2 and send them to the clock terminal 2 of the CCD 50.
0.22, 24 and 26, and horizontal transfer longs φold and φH2 are also generated and supplied to clock terminals 34 and 36; Therefore, by operating the camera shutter button (not shown) to drive the shank 54 and performing exposure movement 1'1, still image information of the subject is accumulated in the imaging cell array 10.
You can also take still photos.

CC for constructing a pixel array as shown in Figure 1.
The D electrodes are arranged as shown in FIGS. 4 to 6, for example.

For example, in the example shown in FIG. 4, an electrode conductor +00 having a shape as shown in FIG. 7 is used. The electrode conductor 100 is made of a metal such as aluminum or low-resistance polycrystalline silicon, and is connected to a rectangular region 102 approximately half the size of the image pickup cell 12 (FIG. 1). Note that FIGS. 4 to 6 conceptually show the arrangement of electrode conductors, and in order to avoid complication of the drawings, the 11111 layers of insulation between each electrode layer are omitted. However, in reality, as shown in FIG. 9, which shows the partial cross-sectional end face seen from the dashed-dotted line arrow IX-rX that traverses the n-th even-numbered column en in FIG. -5i
) A silicon oxide (S + 02) layer 122 is formed on the epitaxial growth layer formed on the main surface of the substrate +20, and a multilayer electrode conductor +00 is formed thereon alternately with the silicon oxide layer. Note that a channel stop region is formed between each pixel cell in the H direction, and elements are isolated from each other in vertical columns.

The electrode conductors +00 are arranged long in the H direction with a slight overlap +1 (l) in the ■ direction.

As shown from No. 91 Δ, the rectangular regions 102 are arranged so that their upper and lower edges overlap slightly alternately, thereby forming a step in the potential barrier at the electrode boundary in the V direction, and forming a two-layer clock. By driving, charges can be transferred in the V direction.

To explain in more detail 411, with reference to FIG. 4, first even number columns en, en+1 . ．． ．． - etc., rectangular area 1
One set of electrode conductors 100 corresponding to even field transfer locks φe1 and φe2 are arranged such that two adjacent rectangular regions 102 constitute one imaging cell, that is, a pixel 12. is installed. In this state, odd number columns on, on+1 . ．．
．． ．． etc., lead part of electrode conductor +02
4 is passing through, and there should be a space not covered with the electrode conductor in other parts. So next, stack it on top of that, odd number columns on, on÷1. ,,
, etc., the rectangular area 102 also intersects 1 in the V direction.
The other set of electrode conductors 100 corresponding to the odd field transfer locks φo1 and φ02 are arranged so that one imaging cell 12 is formed by two adjacent rectangular regions 102 arranged at 7i. With this arrangement, an imaging cell array 10 is configured in which the imaging cells 12 are shifted by a half pitch in the V direction between odd-numbered columns and even-numbered columns. Of course, a layer 122 of silicon oxide or the like is interposed between the electrode conductors 100.

Each electrode conductor 100 formed in this way is provided with a vertical transfer lock φ01. as shown in FIG. φel.

φ02. and φe2, the even and odd field pixel signals are alternately transferred and read out as described above with reference to FIG.

The electrode arrangement shown in FIG. 5 is also almost the same as that shown in FIG. 4, except that the electrode conductor 130 shown in FIG. 8 is used instead of the electrode conductor 100 shown in FIG. 7. It's just different. In other words, the electrode conductor 130 shown in FIG.
has a similar rectangular area 102 and connection -1'' 104, but differs from the one shown in FIG. 7 in that a lead part 104 is connected to approximately the center of two opposing sides of the rectangular part 102.

The array shown in FIG. 6 includes odd columns on, on+1 . ．． ．． etc., the electrode conductor +00 is added to the even columns en, en+1 . ．． ．．
An electrode conductor of +30 is used for the pixels, and odd-numbered pixels and even-numbered pixels are shifted by 3/4 or 1/4 pitch.

Of course, the arrangement of odd and even numbers may be reversed.

When performing still photography using such a CCD 50, first, the multiple field cross-fields φ01 and φ
By setting 02 as a force and having opposite polarity, and setting the even field clocks φel and φe2 to have opposite phases and opposite polarities, potential wells are formed alternately in every other cell 12 of the imaging cell array 10. do. For example, φ01 is set to high level, φ02 is set to low level, φel is set to low level, and φe2 is set to high level. In this state j11, the shutter 54 is opened, and photocarriers corresponding to the image formed on the array 10 by the imaging lens 52 are generated in these potential wells, and 1 blue is stored.Next, as shown in FIG. 2(A) As shown in , even field clocks φe1 and φe2 are fixed as they are,
Odd field clocks φo1 and φ02 are simultaneously activated, voltages are applied alternately, and odd field pixel signals are read out. When the reading of the pixel signals of the odd field is completed, next, as shown in (B), the clocks φe1 and φe2 of the even field are simultaneously activated and voltages are applied alternately to read out the pixel signal of the even field. . At that time, the odd field clocks φ01 and φ
02 is fixed at any level.

By the way, the idea of the present invention can also be applied to movie shooting.

For example, as shown in FIG. 10, a pixel signal storage section 200 is provided between the imaging cell array 10 and the H-CGD 14 described in connection with FIG. It may also have a capacity that can temporarily store.

In the apparatus shown in FIG. 10, in the case of still photography, the same pixel signal readout operation as in the embodiment shown in FIG. 1 is performed. That is, the pixel signals of the imaging section 10 are then transferred to the storage section 200, and from the storage section 200, as shown by arrows 30 and 32, the H-CGD signals are output from the storage section 200 for every other vertical column alternately between odd and even fields. 14. In this way, the pixel signals accumulated in the imaging cell array 10 are once transferred to the accumulation section 200, so there is no need for an optical shutter as shown in FIG. 354.

In the case of movie shooting, pixel signals are transferred all at once from the imaging section 10 to the storage section 200 during the vertical retrace period of the TV signal, and then when transferred from the "& pixel signal processing section 200 to the H-CGD I4, the odd field Then, as shown by the arrow 30, the storage section 2
00 odd number columns on, ona1. ．． ．． etc., and in the even field, as shown by the arrow 32, the even columns en, en+1 . ．． ．． The TV signal may be outputted from the output 38 by driving the same.

In the apparatus shown in FIG. 10, the storage unit 200 may have a storage capacity for only one field, and in that case, the transfer of pixel signals from the imaging unit 10 to the storage unit 200 is performed using the city number field and the storage capacity. This is done alternately for each vertical column in even fields.

In this way, in the embodiment shown in FIG. 10, still photography and movie photography can be realized with one imaging device.

As described above, according to the present invention, since the vertical columns of the CCD are read out alternately in odd and even fields,
In still photography, it is possible to output a video signal that is compatible with a normal television signal format. Such a frame transfer type charge transfer imaging device can directly output two fields of video signals in an interlaced scanning format from the imaging cell array for one frame, so an imaging device using this device can be used for still photography. suitable.

[Brief explanation of the drawing]

FIG. 1 is a plan view conceptually showing a pixel arrangement in an embodiment of a frame transfer type charge transfer imaging device according to the present invention, and FIG. 2 is a plan view showing two phases each of odd and even fields for driving the imaging cell array shown in FIG. 1. FIG. 3 is a schematic perspective view conceptually showing an embodiment of a still camera using the frame transfer type charge transfer imaging device according to the present invention, and FIGS. 4 to 6 are waveform diagrams showing vertical transfer lock. A plan view showing an example of the arrangement of CCD electrodes for configuring the pixel arrangement shown in Fig. 1, and Figs. 7 and 8 showing examples of the shape of electrode conductors used in the electrode arrangement of Figs. 4 to 6. 10 is a plan view showing another embodiment of the frame transfer type charge transfer imaging device according to the present invention. It is. ：°pi11の、bowk■ 10、、、Imaging cell array +2. ,,Imaging cell 14,,,11 transfer to water CCD 50, ,'CCD 54...Optical shutter 58,,,Drive circuit 100.130. Electrode conductor 102, . . . Rectangular region 104, . . . Connection lead 122, . . . Insulating layer φol, φo2. ．． City number field transfer Number field transfer φe20. Even field transfer lock Figure 2 (A) (B) Figure 10 Figure 7 Figure 81 Figure 9 10 Figure 3

Claims (1)

[Claims] 1. An imaging cell array in which imaging cells are two-dimensionally arranged in horizontal and vertical scanning directions, and a horizontal transfer path arranged along one end of a vertical column of imaging cells in the two-dimensional array. In a frame transfer type charge transfer imaging device that outputs a video signal from the horizontal transfer path by an interlaced scanning method of 1 frame and 2 fields, the imaging device includes: a first set of electrode means for receiving one clock signal and transferring pixel signals accumulated in every other vertical column of imaging cells in the imaging cell array to the horizontal transfer path; and the other field period in one frame. a second set of electrode means for receiving a second clock signal supplied to the imaging cell array and transferring pixel signals accumulated in every other vertical column of imaging cells in the imaging cell array to the horizontal transfer path; and the imaging cell array is configured to form said one field when a first set of electrode means is actuated and to form said other field when a second set of electrode means is actuated;
Note that the imaging cells are arranged vertically in vertical columns and in an intersecting n- direction. A frame transfer type charge transfer imaging device 7 having characteristics II. 2. A clock signal generation circuit that generates a first clock signal during one field period in one frame and a second clock signal during the other field period in the frame; an imaging cell array arranged two-dimensionally in a direction, and a frame transfer type charge transfer imaging device that covers a horizontal transfer path arranged along one end of a vertical column of imaging cells in the two-dimensional arrangement; and the imaging cell array. and an exposure means for exposing a subject image for a desired period of time, and outputs a video signal from the horizontal transfer path using a one-frame, two-field interlaced scanning method. The imaging device includes a first set of electrode means for receiving a first clock signal and transferring pixel signals accumulated in every other vertical column of imaging cells in the imaging cell array to the horizontal transfer path; a second set of electrode means for receiving a second clock signal and transferring pixel signals accumulated in every other remaining vertical column of imaging cells in the imaging cell array to the horizontal transfer path; is configured to form said one field when a first set of electrode means is actuated and to form said other field when a second set of electrode means is actuated;
The imaging cells are arranged in vertical columns and alternately shifted in the vertical direction, whereby a video signal displaying a still image of the subject image exposed by the exposure means for a desired time is transmitted from the water/+i transfer path. A photographing device using a frame transfer type charge transfer imaging device characterized by outputting an image.