KR20010007345A - Solid state image sensor and driving method thereof - Google Patents

Abstract

PURPOSE: A solid video sensor and a driving method of the same are provided to improve the utilization efficiency of the cell and prevent a degradation due to the decrease of the cell size by composing the cell of a vertical charge transition unit and twin photoelectric transform units arranged on both sides of the vertical charge transition unit. CONSTITUTION: A cell(10) consists of twin photoelectric transform units(11) arranged in a horizontal and a vertical charge transition unit(12) between the twin photoelectric transform units(11). The vertical charge transition unit(12) has twin vertical charge transition electrodes(13). The twin photoelectric transform units(11) are arranged on both sides of the vertical charge transition unit(12) following the twin vertical charge transition electrode(13). The horizontal array of the twin photoelectric transform units(11) forms a scanning line.

Description

Solid state image sensor and driving method thereof

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a solid state image sensor and a driving method thereof, and more particularly, to a solid state image sensor and a method of driving the solid state image sensor for use in an electronic still camera or a personal computer.

As a solid-state image sensor for use in an electronic still camera or a personal computer, a charge coupled device (hereinafter referred to as "CCD") is well known. This CCD is composed of cells each consisting of a photoelectric conversion section and a vertical charge transfer section, and the signal charge of the photoelectric conversion section is read out by the vertical charge transfer section.

Scanning methods for reading out signal charges by the vertical charge transfer unit include a sequential scan for sequentially scanning the images along the scan lines and an interlaced scan for scanning the images along the interlaced scan lines. Sequential scanning is used, for example, to display an image on a display device of a personal computer, and interlaced scanning is used, for example, for a standard display device of a television receiver.

As techniques related to the present invention, FIG. 1A shows a conventional cell structure for sequential injection and FIG. 1B shows a conventional cell structure for interlaced use.

FIG. 2A shows the signal charge storage state during the operation of the progressive scan type CCD image sensor, FIG. 2B shows the signal charge reading state, and FIG. 2C shows the signal charge transfer state.

3A shows the signal charge storage state of the interlaced CCD image sensor, FIG. 3B shows the signal charge reading state, and FIG. 3C shows the signal charge transfer state.

First, as shown in FIG. 1A, each of the cells 1 of the progressive scan CCD image sensor has a photoelectric conversion unit 2 and four electrodes 3 each having a width W and a length L. FIG. It includes a vertical charge transfer unit (4) having a. In this example, the vertical charge transfer section 4 at one stage corresponds to one photoelectric conversion section 2 and includes four charge transition electrodes 3. The horizontal columns of these photoelectric conversion units 2 constitute one scanning line.

Referring to Figs. 2A to 2C, the operation of the progressive scan CCD image sensor will be described. As shown in Fig. 2A, all signal charges a, b, c, ... d, A, B, C, ... D, and α, β, γ, ... δ) are read out at one instant as shown in FIG. 2B. Next, as shown in FIG. 2C, the pattern of signal charges thus read from the photoelectric conversion parts, which may be photodiodes, is simultaneously shifted line by line and output from the output circuit section 6 through the horizontal charge transfer section 5.

On the other hand, each of the cells 7 of the interlaced CCD image sensor, as shown in Fig. 1B, has a photoelectric conversion section 2 and two electrodes each having a width W and a length 2L. The vertical charge transfer part 4 is included. In this example, the vertical charge transfer section 4 at one stage encompasses two photoelectric conversion sections 2 arranged in the vertical direction, and includes two charge transition electrodes 8. The horizontal columns of these photoelectric conversion units 2 constitute one scanning line.

Referring to FIGS. 3A to 3C, the operation of the interlaced CCD image sensor will be described. As shown in FIG. 3A, the signal charges stored in the photoelectric conversion unit 2 are stored in the radix lines of the photoelectric conversion units 2. Such as (a, c, ..., AC, ..., and α, γ, ...) are read out at the first time by the vertical charge transfer parts 4 as shown in Figure 3b. It is read in a way. Next, as shown in FIG. 3C, the pattern of all the signal charges thus read is simultaneously shifted line by line and output from the output circuit unit 6 through the horizontal charge transfer unit 5.

Next, at the second time, the charges b, d, ..., B, D, ..., and β, δ, ... stored in the even lines of the photoelectric conversion units 2 are on the odd lines. Similar to the signal charges of the photoelectric conversion units 2 in the circuit, the signals are read, shifted and output.

That is, in the case of an interlaced CCD image sensor, the number of charge transfer electrodes of the vertical charge transfer unit 4 for one photoelectric conversion unit 2 in one cell 7 is two. However, the signal charge transfer of one photoelectric conversion unit 2 is performed by further using two signal charge transfer electrodes 8 belonging to another cell 7 located above or below one cell 7. . This is because at least three electrodes are needed to determine the direction of charge transfer.

In a personal computer or a digital camera, in order to expose all their pixels simultaneously, it is necessary to read all the pixels from the photoelectric conversion sections 2 at once and input them to the vertical charge transfer section 4. In order to satisfy this demand, a sequential scanning system has been used, which is required to determine the charge transition direction, each having cells having four or more charge transition electrodes.

However, as disclosed in Japanese Patent Laid-Open No. Hei 10-150183, interlaced scanning systems have also been used. This interlaced scanning system combines a CCD image sensor and a mechanical shutter, and all the pixels use a mechanical shutter to eliminate the need for simultaneous reading of the pixels from the photoelectric conversion sections 2 to the vertical charge transfer sections 4. Simultaneously exposed for a time, the signal charges are then sequentially read out using interlaced cells 7 after the exposure light is blocked by a mechanical shutter.

With the recent reduction in size and weight of personal computers or digital cameras, a reduction in cell size has been required. However, when the size of such a cell having four electrodes as the sequential injection cell described above is reduced, the photoelectric conversion units 2 constituting the light input unit and the vertical charge transfer units constituting the region to which pixel information is transferred ( 4) must inevitably be reduced.

As shown in Fig. 1A, in the case of the cell 1 of the progressive scanning CCD image sensor, if the size of the cell is only slightly reduced, the size of each photodiode constituting the photoelectric conversion units 2 is reduced, Thus, the sensitivity of the CCD image sensor is lowered. In addition, the area of the vertical charge transfer parts is also reduced, so that the dynamic range is reduced. As a result, the characteristics of the CCD image sensor deteriorate. That is, with the reduction of the cell size, the amount of charge generated by the photoelectric conversion sections 2 and the vertical charge transfer sections 4 decreases, thus causing deterioration of the charge transfer effect. In other words, in the case of a sequential scanning CCD image sensor, the amount of charge to be transferred is determined based on the area of two electrodes 3 of the four electrodes 3 of the vertical charge transfer unit 4 in one step. .

As shown in Fig. 1B, even in the case of an interlaced CCD image sensor, the amount of charge generated by the photoelectric conversion sections 2 and the vertical charge transfer sections 4 decreases with the decrease in the cell size. As in the case of a progressive scan CCD image sensor, the charge transfer effect is degraded. In other words, in the case of an interlaced CCD image sensor, the amount of charge to be transferred is determined based on the region of two electrodes 3 of the four electrodes 3 of the vertical charge transfer unit 4 in one step. . This covers two photoelectric conversion sections 2.

In the case of an interlaced CCD image sensor, the length L of the electrode is smaller than the width W, so there is a problem of reducing the transfer rate. When the charge transfer rate is increased while maintaining the width W of the charge transfer electrode of the vertical charge transfer unit 4, the size of the photoelectric conversion unit 2 of the cell having a certain size is reduced so that the amount of charge to be processed is reduced. Needs to be. Therefore, the electrode width W and the region of the photoelectric conversion unit 2 which are in a mutually trade-off relationship should be balanced.

An object of the present invention is to provide a solid state image sensor having a characteristic that the sensitivity and charge transfer rate do not decrease even when the cell size of the solid state image sensor is reduced.

Another object of the present invention is to provide a method for driving the solid state image sensor.

1A and 1B show a cell structure of a solid state image sensor of the technology related to the present invention, FIG. 1A shows a cell structure of a sequential scan type solid state image sensor, and FIG. 1B shows an interlaced type solid state image sensor. Showing cell structure;

Figures 2a to 2c are for explaining the operation of the progressive scanning solid-state image sensor of the technology related to the present invention, Figure 2a shows a signal charge storage state, Figure 2b shows a signal charge reading state, Figure 2c Shows the signal charge transition state;

3A to 3C illustrate an operation of a conventional interlaced solid-state image sensor, FIG. 3A shows a signal charge storage state, FIG. 3B shows a signal charge reading state, and FIG. 3C shows a signal charge transfer state. Show status;

4 shows a cell structure of a solid state image sensor according to an embodiment of the present invention;

5A to 5F illustrate a scanning method of the cells shown in FIG. 4, FIG. 5A illustrates a signal charge storage state, FIG. 5B illustrates a first signal charge read state, and FIG. 5C illustrates a first method. Shows a signal charge transfer state, FIG. 5D shows a second signal charge read state, FIG. 5E shows a third signal charge read state, and FIG. 5F shows a fourth signal charge read state;

FIG. 6A is a plan view showing the structure of a cell portion constituted with the cells shown in FIG. 4, and FIG. 6B is a cross-sectional view taken along the line I-I 'of 6a;

7A and 7B are waveform diagrams showing respective examples of charge transition clock pulses applied to respective electrodes of the vertical charge transition portion shown in FIG. 4;

8a to 8c show different examples of cell arrays according to the present invention, respectively;

FIG. 9 shows another example of the charge transition clock pulses applied to the respective electrodes of the vertical charge transition portion shown in FIG. 8A;

FIG. 10 shows another example of the charge transition clock pulses applied to the respective electrodes of the vertical charge transition portion shown in FIG. 8B; And

FIG. 11 shows another example of the charge transition clock pulses applied to the electrodes of the vertical charge transition portion shown in FIG. 8C.

※ Explanation of symbols for main parts of drawing

10, 20, 21, 22 ... cell 11 ... photoelectric conversion unit

12 ... Vertical charge transfer part 13 ... Charge-charged electrode

14 ... Horizontal charge transfer section 15 ... Output circuit

31 ... N type semiconductor substrate 32 ... P type semiconductor area

33, 34 ... N-type semiconductor layer 35 ... gate oxide

36 ... P ⁺ type diffusion layer 37 ... light shielding film

Ф1-Ф4 ... Transition Clock Pulse V _T ... Readout Pulse

In order to achieve the above object, in the solid state image sensor according to the present invention, a pair of cells arranged on both sides of the vertical charge transfer unit so that each of the cells and the vertical charge transfer unit and the pair of the photoelectric conversion unit It is characterized by consisting of a photoelectric conversion unit.

With this structure of the cell, the utilization efficiency of the cell is improved and the characteristics of the solid state image sensor such as the sensitivity and the charge transfer effect are not degraded even when the cell size is reduced.

According to the driving method of the present invention, the solid-state image sensor described above may be driven.

Other objects, advantages and configurations of the present invention will become more apparent from the following description, and the embodiments of the present invention will be described in more detail with reference to the accompanying drawings.

4 illustrates a cell structure of a solid state image sensor according to an embodiment of the present invention.

As shown in FIG. 4, each of the cells 10 of the solid state image sensor, that is, the CCD image sensor, has a vertical charge transfer arranged between the pair of photoelectric converters 11 and the photoelectric converters 11 arranged horizontally. It consists of a part 12. The vertical charge transfer unit 12 has a pair of vertical charge transfer electrodes 13. That is, the photoelectric conversion parts 11 are arranged on both sides of the vertical charge transfer part 12 along the charge transition electrodes 13. In other words, in one stage the vertical charge transfer unit 12 is arranged with respect to the two horizontally arranged photoelectric conversion units 11 and the two charge transfer electrodes 13 are arranged in one end of the vertical charge transfer unit 12. Is provided. The horizontal arrangement of the photoelectric conversion parts 11 of the cells 10 constitutes one scan line.

In order to read out the signal charge of any one of the photoelectric conversion parts 11, it belongs to the two charge transition electrodes 13 of the cell 10 and another cell 10 provided directly above or below the cell 10. Two electrodes are used, a total of four electrodes. By adopting such a driving method, since at least three charge transition electrodes can be used to read out the signal charge of any one of the photoelectric conversion portions, the charge transition direction can be determined.

In the case where all the pixels, i.e. all the photoelectric conversion parts of the CCD image sensor with cells each having the structure shown in Fig. 4, are simultaneously exposed at the same time by a mechanical shutter coupled thereto, the CCD image sensor is an electronic device. It can be used for still cameras or personal computers.

5A to 5F illustrate a scanning method of the CCD image sensor having the cells shown in FIG. 4, FIG. 5A illustrates a signal charge storage state, and FIG. 5B illustrates a first signal charge read state. FIG. 5C shows a first signal charge read state, FIG. 5D shows a second signal charge read state, FIG. 5E shows a third signal charge read state, and FIG. 5F shows a fourth signal charge read state. Shows. It should be noted that the wirings for inputting the transition clock pulses to the vertical charge transition electrodes are not shown in FIGS. 5A to 5F.

The driving method of this solid-state image sensor will be described.

As shown in FIG. 5A, light incident on the photoelectric conversion units 11 is converted into signal charges and stored therein. The signal charges stored in the photoelectric conversion parts 11 are sequentially read out of the vertical charge transfer parts 12 through the processes described below.

5A to 5F, for example, the reading of the signal charges of the two photoelectric conversion parts 11 storing the signal charges "a" and "A" results in four electrodes, namely these photoelectric conversion parts 11. Two electrodes 13 of the cell 10-1 to which the cell 10-1 belongs and two electrodes of the cell 10-2 to which the two photoelectric converters 11 storing the signal charges “b” and “B” belong. By using (13). That is, the four charge transfer electrodes of the two vertical charge transfer units 12 constitute one repeating unit, which corresponds to one end of the vertical charge transfer unit.

First, at the first time, the signal charges a, c, ..., I, III,... Of the photoelectric conversion parts 11 in the radix scan lines located on the left side of the vertical charge transfer parts 12. Are respectively read out from the vertical charge transfer parts 12, as shown in Fig. 5B. The patterns of all the signal charges thus read in the vertical charge transfer parts 12 are simultaneously shifted by the amount of charge corresponding to one line, and output through the horizontal charge transfer part 14, as shown in FIG. 5C. It is output from the circuit 15.

Next, at the second time, the signal charges A, C, ..., α, γ, ... of the photoelectric conversion parts 11 in the radix scan lines located on the right side of the vertical charge transfer parts 12. Are read out from the vertical charge transfer parts 12, respectively, as shown in FIG. 5D. The patterns of all the signal charges thus read in the vertical charge transfer parts 12 are simultaneously shifted by the amount of charge corresponding to one line and output from the output circuit 15 through the horizontal charge transfer part 14.

Next, at the third time, the signal charges b, d, ..., II, IV, ... of the photoelectric conversion parts 11 in the even scan lines located on the left surface of the vertical charge transfer parts 12. Are respectively read out from the vertical charge transfer parts 12, as shown in Fig. 5E. The patterns of all the signal charges thus read in the vertical charge transfer parts 12 are simultaneously shifted by the amount of charge corresponding to one line and output from the output circuit 15 through the horizontal charge transfer part 14.

Further, at the fourth time, the signal charges B, D, ..., β, δ, ... of the photoelectric conversion parts 11 in the even scan lines located on the right side of the vertical charge transfer parts 12. ) Are respectively read into the vertical charge transfer parts 12 as shown in FIG. 5F. The pattern of all signal charges thus read out in these vertical charge transfer parts 12 is simultaneously shifted by the amount of charge corresponding to one line and output from the output circuit 15 through the horizontal charge transfer part 14.

FIG. 6A is an enlarged plan view illustrating a structure of a cell part configured with the cells shown in FIG. 4. In this figure, the light shielding film is not shown. FIG. 6A shows only a portion including photoelectric conversion parts which store signal charges "a", "A", "I", "b", "B", and "II" as part of a cell part. Note the show.

FIG. 6B is a cross-sectional view taken along the line II ′ of FIG. 6A. FIG. 6B shows the photoelectric conversion unit 11 including the N-type semiconductor layer 33 in the P-type semiconductor region 32 on the N-type semiconductor substrate 31. The vertical charge transfer parts 12 formed by the P ⁺ type diffusion layer 36 and the N type semiconductor layer 34, the gate oxide film 35, and the polysilicon layer are formed of the vertical charge transfer electrodes 13. It is formed in the semiconductor region 32. In addition, the light shielding film 37 is provided in a region different from the photoelectric conversion section 11.

7A and 7B are waveform diagrams showing examples of vertical charge transition clock pulses applied to the electrodes of the charge transition portion shown in FIG. 6A.

As shown in FIG. 6A, a cell unit including a plurality of cells includes charge transition electrodes 13a to which a transition clock pulse? 1 is input and charge transition electrodes to which a transition clock pulse? 2 is input. 13b, charge transition electrodes 13c to which the transition clock pulses? 3 are input, and charge transition electrodes 13d to which the transition clock pulses? 4 are input.

The charge transfer electrode 13a is arranged on the left side of the vertical charge transfer unit 12 and is connected to the photoelectric conversion unit 11 that stores, for example, the signal charge “a” through the signal charge readout region 16. have.

Similarly, the charge transfer electrode 13b is arranged on the right side of the vertical charge transfer unit 12 and the photoelectric conversion unit 11 stores, for example, the signal charge “A” through the signal charge readout region 16. Is connected to. The charge transfer electrode 13c is arranged on the left side of the vertical charge transfer unit 12 and is connected to the photoelectric conversion unit 11 that stores, for example, the signal charge “b” through the signal charge readout region 16. have. The charge transfer electrode 13d is arranged on the right side of the vertical charge transfer unit 12 and is connected to the photoelectric conversion unit 11 storing, for example, the signal charge “B” through the signal charge readout region 16. have.

The signal charge reading area 16 may be used to connect, for example, the photoelectric conversion section 11 storing the signal charge " a " to the charge transition electrode 13b instead of the charge transition electrode 13a. Any number of charge reading regions 16 may be provided upon request.

As shown in Fig. 7A, when the transition clock pulse? 1 accompanying the read pulse V _T is input to the charge transition electrode 13a at time t1, the signal charges " a " and " I " Is read from the photoelectric conversion section 11 to the vertical charge transfer section 12. The signal charges thus read are stored under the charge transition electrode 13a to which the read pulse V _T is applied. Subsequently, at time t2, the signal charges are charged to which the high voltage V _H is applied, corresponding to the potential change caused by the voltage change of the transition clock pulse from V _T to V _H as shown in FIG. 7A. Stored under the electrodes 13a and 13b. These signal charges are then sequentially transferred between the charge transition electrodes 13b and 13c at time t3, and at time t4, these signal charges are stored below the charge transition electrodes 13c and 13d, respectively. do. The above-mentioned connection operation from the time t1 to the time when the signal charges reach the horizontal charge transition part constitutes one period.

After one cycle as described above, as shown in FIG. 7B, the charge transition clock pulse? 2 accompanying the read pulse V _T is input to the charge transition electrode 13b at time t1, and thus, the signal charge "A" is read from the photoelectric conversion section 11 to the vertical charge transfer section 12.

Next, as shown in FIG. 7C, when the transition clock pulse? 3 accompanying the read pulse V _T is input to the visual charge electrode 13c, the signal charges “b” and “II” are photoelectric. It is read from the converter 11 to the vertical charge transfer unit 12. As shown in FIG. 7D, when the transition clock pulse? 4 accompanying the read pulse V _T is input to the charge transition electrode 13d, the signal charge “B” is vertically charged from the photoelectric conversion unit 11. It is read by the transition part 12.

In this way, all signal charges in the photoelectric conversion sections 11 are output without mixing with each other. Therefore, all signal charges a, A, b, of the photoelectric conversion units 11 belonging to the common repetition unit of the vertical charge transfer unit 12 (in this embodiment, corresponding to four vertical charge transfer electrodes). B) is not read at the same time at the same time.

In this embodiment, the cell 4 of the solid state image sensor shown in FIG. 4 has photoelectric conversion parts 11 on both sides of the vertical charge transfer part 12. That is, two photoelectric conversion parts 11 are provided in one vertical charge transfer part 12. Since the vertical charge transfer section 12 has only two charge transition electrodes 13, the two cells arranged in the vertical direction are commonly used to perform reading and transition of signal charges according to the method shown in FIG. 5. Charge transition electrodes are used. Therefore, one image can be provided by performing the signal charge read operation four times.

In general, the transition rate of signal charge decreases as the charge transition electrode is made longer and increases as the width of the charge transition electrode is made wider. However, it is possible to limit the decrease in the charge transfer speed by changing the area of the charge transfer electrode so that the ratio of electrode width to electrode length is changed.

Assuming that the photoelectric conversion part of the cell 10 of the present invention shown in FIG. 4 is the same size as the photoelectric conversion part of the cell shown in FIG. 1A or 1B, the width of the charge transition electrode 13 is 2W + w. The length of the charge transition electrode 13 is 2L. W and L are the basic units for the electrode width and electrode length of the cell 1 of FIG. 1A or the cell 7 of FIG. 1B, and w corresponds to the isolation as a channel stop provided in each cell to prevent leakage of charge. This is unnecessary by combining the two cells 1 or 7 (W + W, see center vertical line in FIG. 4).

Since it becomes possible to further increase the width of the charge transition electrode 13, each photoelectric conversion section is utilized by using an increased portion of the width of the charge transition electrodes for the photoelectric conversion sections on both sides of the vertical charge transition section 12. It is possible to increase the area of (11), thereby improving the sensitivity of the solid state image sensor. Therefore, this structure can be used to handle the increase in the number of pixels and to deal with such design changes.

8A to 8C show other examples of the cell structure according to the present invention.

In FIG. 8A, the cell 20 includes two vertical charge transfer portions 12 each having two charge transfer electrodes 13 and two photoelectric conversion portions 11 arranged on both sides of the vertical charge transfer portions 12. ) Is included. Therefore, there are four charge transition electrodes 13 in one cell 20. 9 shows an example of the charge transition clock pulses applied to the charge transition electrodes 13 of this cell 20. In this case, the charge transfer amount is substantially half of the cell 10 since the total area of these two charge transfer electrodes that determines the charge transfer amount is substantially half that of the cell 10.

In FIG. 8B, the cell 21 has a vertical charge transfer portion 12 each having two photoelectric conversion portions 11 arranged on both sides of one charge transition electrode 13 and the vertical charge transfer portion 12. It consists of three device sets including a. Therefore, there are three charge transition electrodes 13 in one cell. 10 shows an example of the charge transition clock pulses applied to the charge transition electrodes 13 of the cell 21. In this case, three vertical charge transfer parts 12 arranged in the vertical direction are commonly used by six photoelectric conversion parts 11.

In FIG. 8C, the cell 22 has a vertical charge transfer portion 12 each having two photoelectric conversion portions 11 arranged on both sides of two charge transition electrodes 13 and a vertical charge transfer portion 12. It is composed of three device sets including). Therefore, there are six charge transition electrodes 13 in one cell. 11 shows an example of the charge transition clock pulses applied to the charge transition electrodes 13. In this case, three vertical charge transfer parts 12 arranged in the vertical direction are commonly used by the six charge transfer electrodes 13.

The number of charge transfer electrodes 13 of the cell 21 differs from that of the cell 22, even if the number of photodiodes of the photoelectric conversion section 11 of the cell 21 is the same as that of the cell 22. . Therefore, the ability to store and transfer the signal charge of the cell 22 is substantially twice that of the cell 21. This is because the total area of the four charge transfer electrodes that determine the charge transfer amount of the cell 22 is substantially doubled in the area of the charge transfer electrode that determines the charge transfer amount of the cell 21.

The number of commonly used vertical charge transfer parts 12 arranged in the vertical direction is not limited to three. The number of vertical charge transfer parts 12 arranged in the vertical direction and commonly used may be four or more.

As described above, in the cell of the solid state image sensor according to any one of the above-described embodiments, one of the photoelectric conversion units 11 of 2n (where n is an integer) uses the vertical charge transfer unit 12 in common. Are arranged on both sides of the vertical charge transfer portion (12). For example, at least three charge transition electrodes commonly use two charge transition electrodes of one vertical charge transition part and at least one charge transition electrode of a vertical charge transition part arranged above or below this one vertical charge transition part. This can be used by one vertical charge transfer part of one cell.

Since the reduction of the memory cost and the increase in the operating speed of the CPU are improved at high speed, and the CCD image sensor has been used systematically by using a memory or the like, it is not necessary to read all the pixels of the CCD image sensor at one time. Therefore, it is not necessary to put all the signal charge transfer operations in the CCD image sensor. The signal charge transfer process can be distributed. Also, although the transition region is preferably large, it is not desirable that the region of the photodiodes be affected by making the transition region larger. Therefore, parts that can be used in common are used in common as much as possible.

Therefore, by the solid-state image sensor with the vertical charge transfer parts 12 each formed between the two photoelectric conversion parts 11, the signal charges of all the photoelectric conversion parts 11 are output separately without mixing, and the vertical charges The signal charges of the photoelectric conversion parts 11 that commonly use the repeating unit of the transition part 12 are not read out at the same time. Therefore, deterioration of characteristics such as sensitivity and charge transfer effect of the solid state image sensor, which may occur when the use effect of the cells of the solid state image sensor is enhanced and the cell size is reduced, can be avoided. In conclusion, the performance of the solid-state image sensor can be improved.

As described above, in the solid-state image sensor of the present invention, each of which has a vertical charge transfer unit and cells having photoelectric conversion units arranged on both sides of the vertical charge transfer unit, the vertical charge transfer unit is used by the photoelectric conversion unit. As a result, deterioration of characteristics such as sensitivity and charge transfer efficiency of the solid state image sensor, which may occur when the utilization efficiency of the cells is enhanced and the cell size is reduced, is avoided.

In addition, it may be possible to drive the above-mentioned solid state image sensor by the driving method of the present invention.

As described above, it is apparent that the present invention is not limited to the above embodiments, but may be modified and changed without departing from the spirit and scope of the present invention.

Claims (11)

In the solid state image sensor, each includes a plurality of cells consisting of at least one vertical charge transfer unit and at least one pair of photoelectric conversion units, the photoelectric conversion units are arranged on both sides of the vertical charge transfer unit, respectively And a vertical charge transfer unit together used by the photoelectric conversion units. The solid state image sensor of claim 1, wherein the vertical charge transfer unit commonly uses charge transfer electrodes of vertically arranged (n + 1) cells when n is a positive integer. The solid state image sensor of claim 1, wherein the vertical charge transfer unit comprises at least three electrodes constituting one repeating unit. The solid state image sensor according to claim 1 or 2, wherein all signal charges of the photoelectric conversion units are output without mixing. The solid state image sensor according to claim 1 or 2, wherein the signal charges of the photoelectric conversion units which commonly use the repeating unit of the vertical charge transfer unit are not simultaneously read. The solid state image sensor according to claim 1 or 2, wherein signal charge read areas for connecting the charge transfer electrodes to the photoelectric conversion parts are arbitrarily provided so as to exist at a position where the read photoelectric conversion part is read. . A driving method for driving the solid state image sensor according to any one of claims 1 to 6, wherein both sides of the vertical charge transition portion in the vertical charge transition portion are commonly used to obtain at least two signal charge patterns. And sequentially reading out signal charges of each of the photoelectric conversion units arranged in the photoelectric conversion unit. 8. The driving method as claimed in claim 7, wherein all signal charge patterns read in the vertical charge transfer unit are simultaneously shifted every line and output from the output circuit unit through the horizontal charge transfer unit. 9. A method according to claim 7 or 8, wherein the signal charges are read out when a transition clock pulse carrying an output pulse is input. The driving method according to claim 7 or 8, wherein the signal charges are output from each of the photoelectric conversion parts of (2n) when n is a positive integer in every repeating unit of the vertical charge transfer part. The driving method of claim 10, wherein the signal charges stored in each of the photoelectric conversion parts are sequentially read at different timings.