JPS60187187A - Solid-state image pickup device and its driving method - Google Patents

Abstract

PURPOSE:To obtain a high horizontal resolution by a small number of picture elements, by placing positions of the horizontal direction belonging to each adjacent row of plural photoelectric converting elements arranged in a shape of matrix, so that they are different from each other. CONSTITUTION:Signal charges accumulated in each photoelectric converting element 5 are transferred simultaneously to a vertical transfer CCD(V-CCD) 6 as shown with an arrow, and thereafter, furthermore transferred to a horizontal transfer CCD(H-CCD) 7. In this case, a signal charge obtained from photoelectric converting elements of two rows which are adjacent to each other in the upper and lower parts is transferred to the H-CCD7, transferred successively to a charge detector 8, and detected and outputted. That is to say, a signal of the two row portion is read out in one horizontal period, and it becomes what is called a simultaneously two row read-out method. Accordingly, a space sampling frequency in the horizontal direction becomes two times, and the horizontal resolution is improved remarkably.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a solid-state imaging device and a method for driving the same.

Conventional Structures and Problems Solid-state imaging devices have been actively developed because they have many advantages over image pickup tubes. Among these, interline transfer type CCD (hereinafter abbreviated as IT-CCD)
is considered particularly promising because it has low noise in principle.

A description will be given below with reference to FIG. 1, which shows the overall configuration of a conventional T-CCD.

In this configuration, the signal charges stored in each of the photoelectric conversion elements 1 are transferred to the vertical transfer CCD 2 (hereinafter referred to as V
It is abbreviated as -C-CD. ), then transferred to the horizontal transfer CCD 3 (hereinafter abbreviated as H-CCD), and then transferred to the charge detection section 4, where it is detected and output. This is the basic operation of the IT-CCU. When the photoelectric conversion elements 1 are arranged in a square matrix in this manner, the horizontal resolution of the elements is determined by the number of pixels in the horizontal direction. For example, the horizontal resolution of a currently commonly used device with a horizontal pixel count of about 380 is about 28 OTV lines, and there is great hope for an improvement in the horizontal resolution.

One way to increase resolution is to increase the number of pixels, but this is not always easy to achieve because of problems with microfabrication technology and problems such as reductions in sensitivity and dynamic range.

Purpose of the Invention The present invention provides improvements in sensitivity, dynamic range, etc.
<l.

The present invention provides an interline transfer type COD solid-state imaging device with high horizontal resolution and a method for driving the same without sacrificing much.

Structure of the Invention In order to achieve the above object, the present invention provides a plurality of photoelectric conversion elements arranged in a matrix, in which the photoelectric conversion elements belonging to mutually adjacent rows are arranged such that the positions in the horizontal direction are different from each other. The present invention provides a solid-state imaging device in which vertical transfer means are arranged in a meandering manner, and a method for driving the same, whereby high horizontal resolution can be obtained with a small number of pixels.

Explanation of a practical example This is a practical example of the present invention with a vertical pixel count of 6. This will be explained with reference to FIG. 2, which shows an overall configuration diagram when the number of horizontal pixels is 4. In this embodiment, as shown in the figure, the photoelectric conversion elements 5 are arranged in an array in which every other row is shifted by half a pixel in the horizontal direction. (Hereinafter abbreviated as pixel shifted arrangement.) The signal charges accumulated in each photoelectric conversion element 5 are transferred to the V-CCD 6 and then further transferred to the H-CCD 7 as shown by the arrow. At this time, the signal charge obtained from the photoelectric converter that was closed next to the power source is transferred to the HCCD, and sequentially transferred to the charge detector 8, where it is detected and output. In other words, the signal charge corresponding to the construction cost is It is read out during 1111JJ from 1st water, which is the so-called simultaneous construction cost readout method.For the same number of horizontal pixels, the horizontal spatial sampling 1^J wave number is doubled in the pixel shifted array compared to the square array. The horizontal magnification is 11e.
It can be seen that the direction is -1 d.

The detailed structure of this actual sister example will be explained using FIG. 3. The figure includes six photoelectric conversion elements, v-c
A portion of the imaging unit is shown using a four-phase drive embedded channel CCO as the CD.

In the same figure, 10 is the division by tunnel stopper etc. 11
Regions 12-1 and 12-2 are formed of the first layer of polysilicon, and four clock pulses φ■1 used for four-phase drive
．． φ■2. Of φV3tφV41, φV2 is the transfer electrode to which voltage is applied. Same (14-O.

14-1 is a transfer electrode formed of first layer polysilicon and to which φV4 is applied. 11-1.11-2 and 13
-1 is formed of second layer polysilicon, and each φV1
．． and φV3 are applied. Photoelectric conversion elements 16, 17.
The Shinzuki charge accumulated in 18 is φV2? By putting φv4 under a good pressure state for reading, the surface channel gate region 19 opens and the signals are transferred to the channels of the lower right transfer electrodes 12-1, 14-1, and 12-2. As in the real sister example, all the photoelectric conversion elements G'
If they are in the same direction, the transfer conditions for each light 'iL conversion movement will be different from the snow value V, and flicker etc. will be less likely to occur. In this embodiment, for example, in the A field, two rows of photoelectric conversion elements 16 and 17 are read out in a period of 1,000 seconds. In the next horizontal period, the photoelectric conversion element 1
8 and the two lines below it are read out one by one in one horizontal period. On the other hand, in the B field, the photoelectric conversion elements 17 and 18 are read out during one horizontal period of H seepage from the photoelectric conversion element 16 and the ladle thereon during one water period. Interlaced scanning is performed by considering the combination of construction costs to read out each field in a period of ≤ 1 as described below. Charges transmitted from each photoelectric conversion element are transferred to the V-CCD channel. In the dimension transferred to , both AB and JJjυ are the same, but the subsequent
The driving of COD differs depending on the field. An example of the jj47 motion pulse of this combination is shown in FIG. 4 and will be explained. In the same figure, 20i: Transfer from the optical conversion element in the puff field 11421 is an example of j, jig pulses when transferring from the photoelectric conversion element in the B field and general transfer in both directions of 22r1\r. d in puff field.

Maximum to φV2 and φV4 (marked by F, L) At 711 hours, after transferring the 1-signal charge from the photoelectric conversion element to the channel of the transfer electrode to which φV2 and φV4 are applied, the φV40 channel receives an A/Kohaku creation charge. φV2 and φV3 in the upper row are transferred to the channels of the applied electrodes. Similarly, in the B field, after being transferred from the photoelectric conversion element, the Ih charge that was in the channel of the electrode to which φ■4 is applied is transferred to φV2 one row below.
and φV3 are applied to the transfer 'I-z pole channel. 12111 in Figure 3. To explain, in the puff field, signal charges in the channel of the transfer electrode 14-1 are transferred to the channels of the transfer electrodes 12-1 and 13-1. Similarly, in the B field, the signal charge under the transfer electrode 14-1 is applied to the transfer electrode channel (/C) to which φV3 under the transfer electrode 12-2 and 0:12-2 is applied. I believe that the channel VC of transfer electrode j4-0 is 11-y i7r or transfer electrodes 12-1 and 13-1.
(Pj ”i
The 7'X charge is accumulated in the channel of the transfer electrode to which φV2 and φV3 are applied.

In the above example, in order to increase the maximum transfer charge amount of V-COD, φV2 and φV3 are accumulated in the channel of the transfer electrode to which they are applied, but φV1 and φV21φV
2 and φV31φv3 and φ! 4. Any combination of φv4 and φV1 has bJ function.

Furthermore, for each of the above introductions, V-CCD's
μ final transfer voltage 4; k (just before H-CCD) is φV
49φV1? φV2. φV3? That is V-CCD and H-CCD (D Jf2 field from V-CCD, 1[-
11. Separate vortices for controlling the feed to the CCD
1Lj (-+ means anxiety.

If it is not necessary to increase i/ζ maximum J (transfer charge) + 4 by 1'', it is sufficient to use only φV2 or φV4.

As mentioned above, M! to φV2 and φV3! 6 f of the construction cost
During the horizontal retrace period, the signal charge υ accumulated in the final stage of V-CCD is transferred to H-CC'l), H-CCD
Iy this is sent quickly, 11 signal charges continue 1 water 1'
- During the period, it was sent to the detector and output as a detection output.

As shown in the above, the present invention is capable of transmitting a signal with a Sunflink frequency twice as many as the number of pixels in the water direction of the element during one water period.
The horizontal resolution is significantly improved.

In the above explanation, the V-CCD is a four-phase drive φb, but it is also possible to realize the contents according to the gist of the present invention with a two-phase drive. Also, although it was explained using the polysilicon double layer groove j-4,
If the micro S processing technology is advanced, for example, 1 transfer electrode 11-
1.11-2 is formed from the second layer of polynolycone, 13
-1id The structure formed from the second layer of polysilicon does not deteriorate even if it is reused.

The above explanation explains on what basis the element is formed.
↓Although not mentioned, pJI! (Half-barrel body) JL N-channel device provided with VC on the board, or n-channel device (provided in the so-called p-well formed on the mandrel substrate)
Both channel elements are LiJ functional. Of course, a p-channel element 7 with the polarity reversed is also possible.

JTi: As a means of transferring data, we have explained the simple case of a single bond/element, but other transfer means such as BBD may be used.

In fact, MOSF is used as a reading means from photoelectric conversion elements.
ET A MOS that uses a VC switch and has a so-called MOS type light receiving section that uses a metal layer as a vertical transfer means.
It is also effective for solid-state imaging devices such as type, CPD type, and others.

EFFECTS OF THE INVENTIONSONG As described above, the present invention provides a horizontal position 1! of the photoelectric conversion elements belonging to mutually adjacent rows of a plurality of photoelectric conversion elements arranged in a matrix. The vertical transfer means are arranged in different directions, and the vertical transfer means are arranged in a meandering manner, so that a high horizontal M'l image resolution can be obtained with a small number of pixels. big.

[Brief explanation of the drawing]

Fig. 1 is a schematic diagram for explaining an example of the invention, Fig. 2 is an overall configuration diagram of an actual sister example of the present invention, and Fig. 31 is a schematic diagram for explaining the actual gun example of the present invention in detail. Ft4 diagram, FIG. 4 is a pulse diagram showing an example of 519 motion pulses according to the present invention. 5...Photoelectric conversion element, 6...Short surface transfer CCD
. 7...Water 51 (transfer CCD, 8...charge detection section, 1Q...minute 1□; 4 [r area, 1-1-1
．． 11-2.12-1゜12-2.13-j, 14-
0, 14-1...4 phase, each transfer electrode of drive COD, 16, 17.18-...photoelectric conversion element, 19...
・Surface channel area, 20.21.22...
Driving Hals example. Figure 1? Figure 2 Figure 6 to 7 Figure 31

Claims (5)

[Claims] (1) A plurality of photoelectric conversion elements arranged in a matrix (f),
The photoelectric conversion elements have means for vertically transferring the signal charges accumulated in the photoelectric conversion elements, and the photoelectric conversion elements belonging to adjacent rows are arranged so that the horizontal positions of the photoelectric conversion elements are different from each other, and the vertical A solid-state imaging device characterized in that means for transmitting data in a direction is arranged in a meandering manner. (2) The photoelectric conversion element or the means for vertically transferring data has a side having an angle of 90 degrees or less with respect to the vertical direction.
The solid-state imaging device according to i. (3) The solid-state imaging device according to claim 1 or 2, wherein the means for transferring signal charges from the photoelectric conversion elements is formed in the same shape for all the photoelectric conversion elements. Device. (4) The 11J one-piece imaging device according to claim 1, 2, or 3, wherein the vertical transfer means is constituted by a charge-coupled device. (5) It has a plurality of photoelectric converters r arranged in a matrix and a means for vertically transferring the signal type A accumulated in the photoelectric conversion elements, and the photoelectric conversion elements belonging to adjacent rows are connected to each other. fi′1 in the water direction. , i@( are arranged in different directions, and the charge-coupled devices are arranged in a serpentine shape. The state (lζ and 7, then all 11J distribution f4.71:, Q:r are the same) accumulated in all the photoelectric conversion elements of the device A method for driving a solid-state imaging device in which a transfer voltage is transferred to four channels to which a driving pulse is applied to make the signal ``1 piece 1'';