JP3153910B2 - Charge transfer device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a charge transfer device having a plurality of registers provided in parallel with each other.

[Summary of the Invention]

A charge transfer device according to the present invention is a charge transfer device that transfers charges between at least a first register and a second register provided in parallel with each other, wherein transfer electrodes that transfer charges between the registers are adjacent to each other. The transfer electrodes that are formed as well as function as transfer electrodes for transferring charges in each register, and are adjacent to each other in the direction in which charges are transferred between registers when transferring charges between registers or performing transfer within a resist. Driven by a pulse different from the above, at least the potential of the transfer electrode on the side that receives the charge is made deeper than the potential of the transfer electrode on the side that sends out the charge, so that no transfer register or transfer gate is formed between the registers. Things.

[Conventional technology]

Generally, a charge transfer device such as a CCD has an area for transferring charges called a register on a chip thereof. In the register of the charge transfer device, transfer electrodes for controlling potentials are formed side by side, and a channel region serving as a charge transfer path is formed below the transfer electrodes. Here, the CCD solid-state imaging device is configured by adding a sensor for performing photoelectric conversion to such a charge transfer function. In the color solid-state imaging device, different color transmission type filters are formed, and each sensor is provided corresponding to each color.

For example, in a color linear sensor, one or a plurality of rows of sensor units are formed, and a signal is output for each color.
In a device that arranges sensors corresponding to each color in a line in order,
A register is provided in parallel with the sensor row. Then, signals of the respective colors are collectively transferred from the sensor unit to the register, and the color signals are sorted and read out in the order of output. Further, in an apparatus in which a plurality of rows of sensor units are formed, a register is provided for each sensor row,
Each register outputs each color signal.

Incidentally, the number of registers of the charge transfer device is not limited to one, and a plurality of registers may be provided. For example, when a plurality of registers are formed in parallel, transfer between the registers is required.

FIG. 8 is an enlarged view of a region between registers of the conventional charge transfer device. A first polysilicon layer 81 is formed along the H direction in FIG. This first polysilicon layer 81 functions as a transfer gate between registers.
The second polysilicon layer 82 and the third polysilicon layer 83 are alternately formed at a predetermined pitch in the H direction in the drawing. The respective patterns of the second and third polysilicon layers 82 and 83 extend in the V direction while being bent on the first polysilicon layer 81,
The polysilicon layers 82 and 83 of the third and third layers commonly function as two-phase driven transfer electrodes of the first register 84 and the second register 85. When transferring charges in the V direction, that is, transferring charges between registers, a pulse is supplied to the first polysilicon layer 81, and the charges in the first register 84 are once stored in the first polysilicon layer 81. Is stored at the bottom of Thereafter, the charges stored in the first polysilicon layer 81 are transferred to the second register 82.

[Problems to be solved by the invention]

However, in a color linear sensor, in a device in which sensors corresponding to each color are sequentially arranged in a line, after reading out to a register, transfer deterioration in the register becomes a mixed color on an image. Further, in an apparatus that forms a plurality of registers in correspondence with a plurality of sensor rows, signal processing is burdensome because the positions of the sensor rows are naturally different.

Also, as shown in FIG. 8, a plurality of registers are formed,
To transfer data between registers, it is necessary to form the first polysilicon layer 81 in a long pattern along the H direction. Increase. Further, in the case of performing the transfer of the charges in the H direction by two-phase driving, it is necessary to temporarily store the charges below the first polysilicon layer 81, and the transfer efficiency is deteriorated.

Accordingly, an object of the present invention is to provide a charge transfer device capable of improving charge transfer efficiency and preventing color mixing or the like.

[Means for solving the problem]

A charge transfer device according to the present invention is a charge transfer device that transfers charges between at least a first register and a second register provided in parallel with each other, in order to solve the above-described problem. The transfer electrodes that perform charge transfer are formed adjacent to each other and also function as transfer electrodes that perform charge transfer in each register.When performing in-register transfer, adjacent transfer electrodes change levels or simultaneously. When the charge is transferred between registers by driving with different pulse signals that do not reach the charge accumulation level, at least the potential of the transfer electrode on the charge receiving side is made deeper than the potential of the transfer electrode on the charge sending side. It is.

In other words, the transfer electrodes of the registers that perform inter-register transfer between the registers are configured such that when transferring charges between the registers, the transfer electrodes that are adjacent to each other in the direction in which the charges are transferred between the registers are driven by different pulses and receive at least the charges. The potential of the transfer electrode on the side becomes deeper than the potential of the transfer electrode on the side that sends out electric charges.

For example, when transfer in a register is performed in both the first and second registers, when one of the transfer electrodes adjacent to the transfer electrode of another register is in an accumulation state,
The other transfer electrode is driven so as to be in the non-accumulation state over the accumulation state and the clocks before and after the accumulation state.

In this charge transfer device, the number of registers is not limited to two, but may be three or more.

In addition, in order to solve the above-described problems, the charge transfer device according to the present invention includes a first sensor and a second sensor in which different color transmission filters are formed and receives different lights through the filters. And a sensor array in which the third sensor is arranged in a line, a first register corresponding to the plurality of first sensors, a second register corresponding to the plurality of second sensors, and a plurality of third sensors. A third register corresponding to the sensor. The first to third registers are provided in parallel with the sensor row.

Here, the different color transmission type is a mechanism mainly for decomposing and expressing a visible light region, such as a combination of red, green, and blue, and a combination of cyan, yellow, and magenta. The apparatus uses at least three types of filters. In the sensor row, a combination of sensors is arranged in a straight line, and the order of the sensors does not matter.
Although the register is provided in parallel with the sensor row, the register may be provided only on one side of the sensor row, or the register may be provided on both sides of the sensor row.

The transfer electrode of each register that performs inter-register transfer between the registers is formed adjacent to each other and also functions as a transfer electrode that performs charge transfer in each register. When the transfer electrodes are driven by different pulse signals that do not simultaneously change the level or simultaneously reach the charge accumulation level, and transfer the charges between the registers, at least the potential of the transfer electrode on the side that receives the charges and the side that sends the charges Is made deeper than the potential of the transfer electrode.

In this charge transfer device, the number of registers is not limited to two, but may be three or more.
Further, a structure having an imaging unit can be adopted, and the shape of the imaging unit such as a linear sensor and an area sensor is not limited.
Further, the charge transfer device may include an imaging unit having a color filter. Further, a structure having an imaging unit can be adopted, and the shape of the imaging unit such as a linear sensor and an area sensor is not limited. Further, the charge transfer device may include an imaging unit having a color filter.

Further, the transfer electrodes that are adjacent to each other and perform the transfer between the registers may be formed by increasing the electrode width on the adjacent side. Further, among the transfer electrodes which are adjacent to each other and perform the transfer between the registers, a transfer portion may be formed on the side adjacent to the transfer electrode on the side receiving the charge.

[Action]

In the charge transfer device according to the present invention, the transfer electrodes of different registers are adjacent to each other, so that the charge transfer between the registers is performed directly. Further, the transfer charge for transferring the charge between the registers also functions as a transfer electrode when transferring the charge in the register. Then, by driving the transfer electrodes adjacent to each other in the direction in which the charges are transferred between the registers with different pulses, and controlling the potential to increase from the sending side to the receiving side, the charge is transferred from the sending side to the receiving side. Is transferred between the registers.

Further, in the charge transfer device according to the present invention, since the registers are arranged in correspondence with the sensors for each color, there is no problem of color mixing because the registers and the color signals correspond one-to-one. Further, since the sensors are arranged in a line, it is possible to obtain image information on the same line without displacement.

〔Example〕

Preferred embodiments of the present invention will be described with reference to the drawings.

First Embodiment This embodiment is an example of a CCD, which has first and second registers, can perform charge transfer in each register, and can also perform charge transfer between registers. You can do it.

FIG. 1 is a plan view of the register portion. In this register portion, a first register 1 and a second register 2 for transferring charges in the H direction in FIG. Is formed on. The first register 1
The second register 2 has transfer electrodes 8, 4, 9, and 10, and has transfer electrodes 5, 3, 6, and 7. Although not shown, a channel for transferring electric charges is formed below these transfer electrodes 3 to 10. The transfer electrode 3 of the first register 1 is formed adjacent to the transfer electrode 4 of the second register 2 so that one side of the transfer electrode 3 abuts. There is no transfer gate or the like between the transfer electrode 3 and the transfer electrode 4. The transfer electrodes 3 and 4 are adjacent to each other, but for the other transfer electrodes 5 to 10, a channel stopper region 11 is formed between the first and second registers 1 and 2, and the channel stopper region 11 Electrically isolated. Transfer electrode 3
Is formed so as to expand on the second register 2 side and narrow on the opposite side. That is, the transfer electrode 3
It is formed in a substantially trapezoidal shape, and has an electrode width that extends in the V direction in the direction of transferring electric charges. Similarly, the shape of the transfer electrode 4 is also substantially trapezoidal, and is formed such that the electrode width on the adjacent side is increased. Still another transfer electrode 5
Similarly, the patterns # 10 to # 10 have a substantially trapezoidal pattern. Since each of the transfer electrodes 3 to 10 is formed in a substantially trapezoidal shape, the potential of the peripheral portion of the transfer electrode is increased at the widened side and is reduced at the narrowed side, thereby improving the transfer efficiency. .

Each of the transfer electrodes 3 to 10 having the above-described shape is formed of, for example, three polysilicon layers. In this embodiment, the transfer electrodes 4 and 7 are formed of the first polysilicon layer, and the transfer electrodes 3 and 10 are formed of the second polysilicon layer. That is, the transfer electrodes 3, where transfer between the registers is performed,
In the adjacent portion 12 of 4, a part of the transfer electrode 3 overlaps the transfer electrode 4. The transfer electrodes 5, 6, 8, and 9 are formed using a third polysilicon layer. Although illustration is omitted,
Above the channel stopper region 11, a layer to which signals of the same phase described below are supplied is formed as a continuous pattern.

Then, the first-phase signal Φ1 is supplied to the transfer electrodes 3 and 10, and the third-phase signal Φ3 is supplied to the transfer electrodes 4 and 7. The transfer electrodes 5, 6, 8,
9 is supplied with a second-phase signal Φ2 or a fourth-phase signal Φ4. Specifically, the transfer electrodes 5 and 9 apply a fourth-phase signal Φ
4 is supplied to the transfer electrodes 6 and 8, and the second-phase signal Φ2 is supplied to the transfer electrodes 6 and 8.

The CCD having the above-described structure according to the present embodiment can perform transfer between registers (transfer in the V direction) and also transfer in registers (transfer in the H direction).

With reference to FIG. 2, the operation of transferring the electric charge existing on the transfer electrode 3 to the transfer electrode 10 will be described. First,
Only the time t ₀ a first phase signal at Φ1 is "H" level (high level), other signals Φ2~Φ4 is an "L" level (low level). At this time, the electric charges are accumulated below the transfer electrode 3. At time t ₁ of the next clock signal Φ3 of the third phase becomes the "H" level from the "L" level, the charge transfer electrode 3 flows to the transfer electrode 4. At this time, the transfer electrodes 8 and 9 adjacent to each other in the register of the transfer electrode 4 are both at the “L” level, and the transfer of the charge is stopped only in the region over the transfer electrode 4. At time t ₂ of the next clock, the signal Φ1 of the first phase is changed to the "L" level. Then, the potential of the transfer electrode 4 on the side that receives the charge becomes deeper than the potential of the transfer electrode 3 on the side that sends out the charge, and all the charge accumulated in the transfer electrode 3 flows to the transfer electrode 4,
Transfer between registers will be performed. Next, at time t _3, the signal Φ4 of the fourth phase is changed to "H" level from the "L" level, the charges transferred to the transfer electrode 4 transfer electrodes 9
Flow up to. Then, at time t _4, the signal Φ3 according to the transfer electrode 4 changes to "L" level, charges are accumulated in the transfer electrodes 9, the charge transfer electrodes at time t ₅ of the next clock
Transfers up to 10.

Similarly, in the transfer in the register, the signal supplied to the transfer electrode to which the charge is to be transferred next is changed from the “L” level to the “H” level, and then the signal is transferred to the transfer electrode that has accumulated the charge. This is performed by lowering the supplied signal from the “H” level to the “L” level and sequentially proceeding this. In particular, by controlling such transfer electrodes, during transfer within the register, the first-phase signal Φ1 and the third-phase signal Φ3 supplied to the transfer electrodes 3 and 4 where transfer between registers is performed. The level does not change at the same time, or does not attain the “H” level at the same time. When one of the charges exists, the other is always held at the “L” level. Therefore, it is possible to reliably transfer the electric charge in the H direction in the register.

As described above, the CCD according to the present embodiment can transfer charges in the V direction between the registers by using the transfer electrodes 3 and 4 by driving the adjacent transfer electrodes with different pulses, and at the same time, the H level in the registers can be increased. Direction transfer can also be performed. In the transfer between the registers, the adjacent transfer electrode
Since the transfer is performed between 3, 4
This eliminates the necessity, solves problems such as gate resistance, and improves the transfer efficiency. In particular, in the charge transfer in the V direction, since the shape of the adjacent transfer electrodes 3 and 4 is formed so as to expand in the adjacent portion 12, it is possible to improve the charge transfer efficiency.

Second Embodiment This embodiment is an example of a color linear CCD, and has first to third registers.

The main part of FIG. 3 is shown. First, sensor row 20
Are formed with the H direction in the figure as the longitudinal direction. The sensor array 20 includes a first sensor 24 having a filter for receiving red (R), a second sensor 25 having a filter for receiving green (G), and a blue (B). And a third sensor 26 having a filter for receiving light.
The first sensor 24 obtains a charge corresponding to the red color signal, the second sensor 25 obtains a charge corresponding to the green color signal, and the third sensor 26 converts the charge to a blue color signal. An appropriate charge is obtained.

In the V direction in the figure of the sensor array 20, the gate regions 27 to
30 are formed. The gate regions 27 to 30 function as gates for selectively reading out signal charges from the sensor array 20 in accordance with the sensors 24 to 26. On the V direction side of each first sensor 24, a gate region to which the signal G1 is supplied
27, a gate region 28 to which the signal G2 is supplied is provided on the V direction side of each second sensor 25, and a signal G3 is supplied to the V direction side of each third sensor 26. A gate region 29 is provided. Then, a set of each gate region 27
A gate region 30 controlled by the signal G4 is formed in units of .about.29 so as to face the gate regions 27 to 29 further in the V direction. This gate region 30 is the first region of the register described below.
To the register 21 of FIG. Such a gate region 27-30
If only one of the signals G1 to G3 is set to the read level (for example, “H” level) in order to take out the color signal alternatively, and at the same time the signal G4 applied to the gate region 30 becomes the read level, The reading of the electric charge for each color signal from the sensor array 20 is performed.

In the CCD of the present embodiment, first to third registers 21 to 23 are formed in parallel with a sensor array 20 having such a gate for each sensor. In each of the registers 21 to 23, the transfer electrodes 31, 32, 33, and 34 are repeatedly formed in order in the H direction. Each transfer electrode 31 is supplied with a first-phase signal Φ1, each transfer electrode 32 is supplied with a second-phase signal Φ2, and each transfer electrode 33 is supplied with a third-phase signal Φ3. ,
Further, a fourth-phase signal Φ4 is supplied to each transfer electrode. Here, the transfer electrodes 32 and 34 are not adjacent between the registers, and are electrically separated by the channel stopper region 35 between the registers, and are adjacent to the other transfer electrodes 31 and 33 only within the register. . The transfer electrode 31 is sandwiched between the transfer electrodes 32 and 34 in each of the registers 21 to 23. In the first register 21 and the second register 22, one side of the transfer electrode 31 abuts on the transfer electrode 33 on another register in the V direction. Adjacent to each other. The transfer electrode 31 functions as a horizontal transfer electrode in each register, and in the first register 21 and the second register 22, functions as a transfer electrode on the side that sends out electric charges in transfer between the registers. Similarly, the transfer electrode 33 is also sandwiched between the transfer electrodes 32 and 34 in each of the registers 21 to 23, and
In the direction, it is adjacent to the transfer electrode 31 on another register in a shape in which one side is abutted. The transfer electrode 33 functions as a horizontal transfer electrode in each register, and also functions as a transfer electrode on the side that receives charges in transfer between registers and transfer from the sensor array 20. Each of these transfer electrodes 31
The transfer electrodes 32 and 34 have a substantially trapezoidal shape, and the transfer electrode 31 is formed in a pattern such that the transfer electrode 33 side and the transfer electrode 33 are expanded in the transfer electrode 31 side. . For this reason, the potential of the expanded portion can be made deeper than that of the narrow portion, and the transfer efficiency of transfer between registers and transfer within the register can be improved.

The transfer electrodes 31 to 34 of each of the registers 21 to 23 are formed of, for example, three polysilicon layers as in the first embodiment. In this embodiment, the transfer electrode 33 is formed of a first polysilicon layer, the transfer electrode 31 is formed of a second polysilicon layer, and the transfer electrodes 32 and 34 are formed of a third polysilicon layer. It is formed using a silicon layer. Although illustration is omitted,
Each layer may be extended to above the channel stopper region 35 to form a pattern in which layers to which signals of the same phase are supplied are continuous.

Next, the transfer of electric charges in the V direction will be described with reference to FIG. It is assumed that charges corresponding to color signals are alternatively transferred from the sensors 24 to 26 by the selection operation of the gate regions 27 to 30, and the charges are now accumulated below the transfer electrodes 31. At this time, the signal Φ1 is at the “H” level, and the other signals Φ2 to Φ4 are at the “L” level (at time
t _0). When transferring between registers Here, in FIG. 4, the signal Φ3 at time t ₁ is changed to "H" level, the transfer electrodes
The electric charges accumulated in the lower part of the base 31 flow out to the lower part of the transfer electrode 33. Then, the signal Φ1 at time t ₂ is "H" level to "L"
Level, the potential of the transfer electrode 33 on the side that receives the charge becomes deeper than the potential of the transfer electrode 31 on the side that sends out the charge, and all the charges accumulated in the transfer electrode 31 are transferred to the transfer electrode 33 and transferred. Electric charges are stored only in the lower part of the electrode 33. During this time, the signals Φ2, Φ4 are always at “L” level, and the transfer electrodes 32, 3 applied to these signals Φ2, Φ4 are
There is no charge flowing into 4. The transfer of the electric charge in the V direction is performed by such a drive pulse, and the electric charge is transferred from the sensor array 20 to the first register 21 and the first register 21 is transferred.
The transfer of charge from the second register 22 to the second register 22 and the transfer of charge from the second register 22 to the third register 23 can be performed completely in parallel.

Next, the transfer in the H direction, which is a transfer in the register, will be described with reference to FIG. The transfer in the H direction is performed by alternately repeating a clock for setting a region relating to two transfer electrodes to a charge accumulation state and a clock for setting a region relating to only one transfer electrode to a charge accumulation state.

First, at time t _0, a signal Φ1 only the "H" level, the other signal Φ2~Φ4 is "L" level. Therefore,
Even when the signal Φ1 is at the “H” level, no charge flows from the region of the transfer electrode 31 to the region of the transfer electrode 33 because the signal Φ3 is at the “L” level.

Next, at time t _1, the signal Φ2 is changed to "H" level from the "L" level. Charge existing only in the region of the transfer electrode 31 flows into the region of the transfer electrodes 32, the signal Φ1 at the next time t ₂
Changes to the “L” level, so that charges are accumulated only in the lower part of the transfer electrode 32.

Next, when the signal Φ1 becomes “L” level and no electric charge is present in the area of the transfer electrode 31, the signal Φ3 becomes “H”.
It changes to the level (time t ₃ ). As a result, the charges in the region of the transfer electrode 32 flow into the region of the transfer electrode 33. At this time,
Since the signal Φ1 is at the “L” level, no charge is transferred to the region of the transfer electrode 33 via the region of the transfer electrode 31. Then, the signal Φ2 at time t ₄ is "L" level and the charge only to the transfer electrodes 33 are accumulated.

Hereinafter, over time t ₅ ~t _8, the signal Φ4 goes "H" level, then the signal Φ3 goes "L" level, then,
The signal Φ1 goes to the “H” level again. As a result, the electric charges in the area of the transfer electrode 33 are transferred to the area of the transfer electrode 31 via the area of the transfer electrode. During this time, there is no possibility that both the signal Φ1 and the signal Φ3 go to the “H” level or change their levels at the same timing. Therefore, transfer between the registers in the V direction is not performed. Then, by the transfer in the H direction of each of the registers 21, 22, and 23, charges corresponding to each color signal are extracted for each of the registers 21 to 23.

In such a CCD according to the present embodiment, transfer between registers (transfer in the V direction) can be performed between adjacent transfer electrodes, and the electrode performing the transfer in the V direction is transferred in the register in the H direction. Can also be used as a transfer electrode.
Therefore, it is not necessary to form a transfer gate between the registers, and the transfer efficiency is improved. In addition, the color signals extracted from one sensor row 20 can be transferred without any positional gap, and the registers 21 to 23 can be used for each color, so that color mixing or the like is prevented beforehand. .

Third Embodiment This embodiment is an example of a color line sensor, in which three registers are independently provided for three colors.

As shown in FIG. 6, the line sensor of this embodiment
A sensor row 40 having the H direction as a longitudinal direction is formed. The sensor array 40 includes a first sensor 44 having a filter for receiving red (R) and a green (G).
Sensor 45 having a filter for receiving light
And a third sensor 46 having a filter for receiving blue (B) light are sequentially arranged in a straight line. The same H direction parallel to this sensor row 40 is taken as the longitudinal direction,
On one side of the sensor array 40, three registers 41, 42, 43 are provided. These first to third registers 41 to 43
Transfers charges sequentially in the H direction. Further, between these registers 41 to 43, transfer between the registers in the V direction in the figure can be performed. Output circuits 47, 48, and 49 are provided at the ends of the registers 41 to 43 in the H direction. These output circuits 47, 48, and 49 output output signals corresponding to the signal charges transferred by the registers 41, 42, and 43, respectively.

In the line sensor having such a structure, each of the sensors 44 to 46, which is a region for receiving light, is arranged in a line.
There is no positional deviation for each color. Then, the first register 41,
The electric charge is distributed to the second register 42 and the third register 43.

First, at time t ₀ , as shown by the dashed line in the figure, the signal charge relating to the red signal is read from the first sensor 44 to the first register 41. At this time, no charge is read from the second and third sensors 45 and 46.

Next, at time t _1, the signal charges according to the previously read red signal from the first register 41 as indicated by a broken line in FIG into the second register 42 is transferred. At the same time, as shown by the broken line in the figure, the signal charge of the green signal from the first sensor 45 is read out to the first register 41. This means that the charge related to the red signal has been read to the second register 42 and the charge related to the green signal has been read to the first register 41.

Next, at time t _2, the as shown by the solid line in the figure, the signal charges according to the red signal transferred to the second register 42 is a third
And the signal charge relating to the green signal is transferred from the first register 41 to the second register 42.
Then, at this time, the signal charge related to the blue signal is transferred from the sensor array 40 to the first register 41. as a result,
By such transfer between registers, the first register
The signal charge relating to the blue signal is stored in 41, the signal charge relating to the green signal is stored in the second register 42, and the signal charge relating to the red signal is stored in the third register 43. . Hereinafter, the electric charge in the H direction is transferred by each of the registers 41 to 43, and the output for each color signal is extracted from each of the output circuits 47 to 49.

As described above, in this embodiment, signals can be extracted for each color signal, which is advantageous for signal processing. In addition, each register
As for the pitch of the transfer electrodes 41 to 43, since there is a register independent for each color, there is a margin, and the transfer efficiency can be increased by lowering the transfer frequency.

Fourth Embodiment This embodiment is a modification of the third embodiment, in which registers are provided on both sides of a sensor array.

As shown in FIG. 7, in the line sensor of this embodiment, a sensor row 50 having the H direction as a longitudinal direction is formed. The sensor array 50 includes a first sensor 54 having a filter for receiving red (R), a second sensor 55 having a filter for receiving green (G), and a blue (B) ) And a third sensor 56 having a filter for receiving) are linearly arranged in order. On both sides of this sensor row 50, three registers 5
1,52,53 are provided. The first register 51 and the second register 52 include a sensor array on one side of the sensor array 50.
The third register 53 is provided on the other side of the sensor row 50 in parallel with the sensor row 50 and has the H direction in the figure as the longitudinal direction. I have. Each of these registers 51 to 53 can sequentially transfer charges in the H direction. In addition, each register
Output circuits 57, 58,
59 are arranged. These output circuits 57, 58, 59 output output signals corresponding to the signal charges transferred by the registers 51, 52, 53. Then, between the first register 51 and the second register 52, electric charge transfer between the registers can be performed. From the sensor row 50, the first and third registers can be transferred.
The signal charges for each color can be read out for each of 51 and 53.

The operation will be described with reference to FIG.
At t ₀ , as shown by the broken line in the figure, first, the charge applied to the red signal from the first sensor 54 is read out to the first register 51. At this time, the second and third sensors in the sensor row 50
No charge is read from 55 and 56.

Next, as shown in solid line in the figure at time t _1, the charge of the first red signal which has been read out in the register 51 is sent by the transfer between the registers in the second register 52. At the same time, as shown by the solid line in the figure, the electric charge relating to the green signal is transferred from the second sensor 55 of the sensor array 50 in the V direction in the figure and sent to the first register 51. From the third sensor 56 of 50, the electric charge relating to the blue signal is transferred in the −V direction in the figure and sent to the third register 53. As a result, the first register 51 stores the charge related to the green signal, the second register 52 stores the charge related to the red signal, and the third register 53 stores the charge related to the blue signal. Is done. Then, the charge in the H direction is transferred by each of the registers 51 to 53, and the output for each color signal is extracted from each of the output circuits 57 to 59.

In the line sensor of this embodiment having such a structure, signals for each color can be obtained from each of the registers 51 to 53, and there is no problem such as color mixing. In addition, each of the registers 51 to 53 only transfers a single signal, so that the number of transfer electrodes for the H-direction transfer of the registers 51 to 53 can be suppressed and an interval can be provided. And the transfer efficiency can be increased. Further, as compared with the line sensor of the third embodiment, the transfer between the registers is performed by the first register 51.
To the second register 52 only once, and the control signal to the register can be simplified.

Fifth Embodiment This embodiment is a modification of the first embodiment, and has a first register 91 and a second register 92 for transferring charges in the H direction in the figure. This is an example in which transfer in the V direction between two registers 91 and 92 is enabled.

FIG. 9 is a plan view of a main part, in which a first register 91 and a second register 92 for transferring charges in the H direction are H
They are formed parallel to each other with the direction being the longitudinal direction. The first register 91 has transfer electrodes 93, 95, 96, 97, and the second register 92 has transfer electrodes 94, 98, 99, 100. Although the first register 91 and the second register 92 are electrically separated by the channel stop region 102, the transfer electrode 93 and the transfer electrode 94 project to the channel stop region 102 so that one side thereof abuts. The transfer electrodes 93 and 94 are adjacent to each other, and the channel is continuous via the adjacent portion 103. These transfer electrodes 93, 94
Are formed in a substantially trapezoidal shape, and are formed so as to expand toward the adjacent portion 103 side. Also, other transfer electrodes 95 to
100 is also formed in a substantially trapezoidal shape. In this way, each of the transfer electrodes 93 to 100 can have a substantially trapezoidal shape, so that the potential on the expanded side can be deepened.
The transfer efficiency can be improved.

Each of the transfer electrodes 93 to 100 is supplied with one of four-phase transfer signals Φ1 to Φ4. Transfer electrode 95,1
00, the first phase signal Φ1 is supplied, and the transfer electrodes 94, 96
Is supplied with a second-phase signal Φ2. Transfer electrodes 97, 98
Is supplied with a third-phase signal Φ3, and the transfer electrodes 93 and 99 are supplied with a fourth-phase signal Φ4. Further, of the transfer electrodes 93 to 100, the lower region of the transfer electrodes 95, 97, 98, and 100 to which the signals Φ1 and Φ3 are supplied is a transfer unit. The lower region of the transfer electrodes 93, 94, 96, and 99 to which the signals Φ2 and Φ4 are supplied is a storage portion having a deeper potential well than the transfer portion. As described above, in each of the registers 91 and 92, the storage section and the transfer section are formed alternately, and the transfer efficiency can be increased. In particular, the lower region of the transfer electrode 94 is generally a storage portion, and a transfer portion 101 is formed in a region adjacent to the storage portion. Therefore, when the channel region below the transfer electrode 94 is returned to the non-accumulation state, the adverse effect that charges remain in the adjacent portion 103 is suppressed, and the transfer efficiency between registers in the V direction can be improved. .

FIG. 10 is a diagram schematically showing the transfer between registers in the V direction. As shown in FIG. 10, a transfer portion 101 is formed on the transfer electrode 94 side of the adjacent portion 103, and only in a region where the transfer portion 101 is formed,
The potential well in the lower region of the transfer electrode 94 becomes shallower,
The electric charges are transferred from the lower region of the “L” level transfer electrode 93 to the lower region of the “H” level transfer electrode 94. At this time, since the transfer portion 101 is formed,
Backflow of the transfer charge from the lower region of the transfer electrode 94 to the lower region of the transfer electrode 93 is prevented.

Also, in the case of performing the transfer in the register in the H direction, similarly to the first embodiment, the signal supplied to the transfer electrode to which the charge is to be transferred next is changed from the “L” level to the “H” level. After that, the signal supplied to the transfer electrode that has accumulated the electric charge is changed from “H” level to “L” level, and the signal is sequentially advanced.

By the way, regarding the transfer in the H direction, even when both of the transfer electrodes adjacent to each other become “H” level (high level),
Charge can be transferred by the potential difference. FIG. 11 is a diagram schematically showing the transfer in the register in the H direction. 3 adjacent to each other in the same register
The signal Φ of the four-phase signal is applied to the two transfer electrodes 96, 97, and 93.
2, Φ3, Φ4 are supplied. At this time, in the first embodiment which is the basis of the present embodiment, as shown in FIG. 11A, when the signal Φ4 is at the “H” level and the signal Φ3 is at the “L” level, When the signal Φ3 is changed from the “H” level to the “L” level, a potential dip 105 is formed in an overlap portion between the transfer electrode 96 and the transfer electrode 97, and this dip 1
The electric charge will flow in 05.

In this embodiment, when charges are transferred from the transfer electrode 96 to the transfer electrode 93, the signals Φ2, Φ3, and Φ4 are supplied so as to form a potential that becomes deeper in the transfer direction.
During this time, as shown in FIG. 11 (b), the lower region of the transfer electrode 97 becomes the transfer portion and the lower region of the transfer electrode 93 becomes the storage portion. For example, both the signals Φ3 and Φ4 are at the “H” level (high level). It may be. Also in this case, since the transfer portion is formed in the lower region of the transfer electrode 97, the electric charge accumulated in the region of the signal Φ2 can be transferred to the region of the signal Φ4 by the potential difference. Thereafter, as shown in FIG. 11 (c), the signal Φ3 becomes “L” level and the transfer electrode 93
To form a barrier. Thus, when the signal Φ4 is at the “H” level and the signal Φ2 is at the “L” level, even if the signal Φ3 changes from the “H” level to the “L” level, the charge is prevented from flowing backward. be able to.

In the first embodiment, which is the basis of the present embodiment, the charge transfer efficiency is determined by the time required for the signal supplied to the transfer electrode, which has accumulated the charge, to fall from the "H" level to the "L" level. On the other hand, in this embodiment, the charge transfer efficiency is determined by the pulse width of the signal for driving the transfer electrode. Therefore, in the present embodiment, the charge transfer efficiency depends not on the fall time of the clock pulse, which is difficult to control accurately, but on the width of the clock pulse that can be controlled easily and reliably. It can be secured for a long time. Therefore, efficient transfer is realized similarly to the transfer in the V direction.

〔The invention's effect〕

In the charge transfer device of the present invention, since the transfer electrodes of different registers are adjacent to each other, the charge transfer between the registers is performed directly, so that the charge transfer between the registers does not require a structure such as a transfer gate. This operation is performed without accumulating charges once in the gate portion. For this reason, the transfer efficiency of charges can be improved.

In addition, when charge transfer between registers or transfer within a resist is performed, adjacent transfer electrodes in the direction in which charges are transferred between registers are driven by different pulses from each other, so that charges leak below the adjacent transfer electrodes. Can be prevented.

Furthermore, the charge transfer device of the present invention can have a structure in which registers are arranged in correspondence with sensors for each color, so that color mixing can be prevented in one-to-one correspondence between registers and color signals, and each sensor in the sensor row Since they are arranged in a line, it is possible to obtain image information on the same line without displacement.

[Brief description of the drawings]

FIG. 1 is a plan view of an essential part of an example of the charge transfer device of the present invention, FIG. 2 is a waveform diagram for explaining an example of the charge transfer operation, and FIG. 3 is another example of the charge transfer device of the present invention. FIG. 4 is a plan view of a main part of one example, FIG. 4 is a waveform diagram for explaining a V-direction transfer operation of another example of electric charge, and FIG. 5 is a diagram for explaining an H-direction transfer operation of another example of the above electric charge. FIG. FIG. 6 is a block diagram showing the configuration of still another example of the charge transfer device of the present invention, and FIG. 7 is a block diagram showing the configuration of still another example of the charge transfer device of the present invention. FIG. 8 is a plan view of an essential part showing an example of a conventional charge transfer device. FIG. 9 is a plan view of a principal part of still another example of the charge transfer device of the present invention, and FIG. 10 is a schematic potential diagram for explaining the transfer operation between registers of the example of FIG. No.
FIG. 11 is a schematic potential diagram for explaining the transfer operation in the register of the example of FIG. 1,21,41,51... First register, 2,22,42,52... Second register, 3-10,31-34... Transfer electrode, 20,40,50. 23, 43, 53… third register, 24, 44, 54…
First sensor, 25, 45, 55 ... second sensor, 26, 46,
56: Third sensor, 11, 35: Channel stopper area, 27 to 30: Gate area, Φ1 to Φ4 ... Signal

Continuation of the front page (56) References JP-A-59-106148 (JP, A) JP-A-60-182892 (JP, A) JP-A-62-76960 (JP, A) JP-A-63-9153 (JP, A) , A) JP-A-60-130978 (JP, A) JP-A-59-218700 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H01L 27/14-27/148 H01L 29/762-29/768 H04N 5/335

Claims (4)

(57) [Claims] 1. A charge transfer device for transferring charges between at least a first register and a second register provided in parallel with each other, wherein transfer electrodes for transferring charges between the registers are formed adjacent to each other. In addition, the pulse signal functions as a transfer electrode for transferring charges in each of the registers. When performing the transfer in the register, different pulse signals that do not simultaneously change the level of the adjacent transfer electrodes or simultaneously reach the charge accumulation level. A charge transfer device, wherein at least the potential of the transfer electrode on the side receiving the charge is made deeper than the potential of the transfer electrode on the side sending the charge when the charge is transferred between the registers. 2. The charge transfer device according to claim 1, wherein each of the adjacent transfer electrodes for performing the inter-register transfer is formed such that the electrode width on the adjacent side is increased. . 3. A transfer section is formed on a side adjacent to a transfer electrode on a charge receiving side, among transfer electrodes formed adjacent to each other and performing transfer between registers. 2. The charge transfer device according to claim 1. 4. A sensor array in which a first sensor, a second sensor, and a third sensor, each having a different color transmission type filter and receiving different light through the filter, are arranged in a line. A first register corresponding to the plurality of first sensors, a second register corresponding to the plurality of second sensors, and a third register corresponding to the plurality of third sensors. The first to third registers are provided in parallel with the sensor row, and the transfer electrodes of the registers that perform inter-register transfer between the registers are formed adjacent to each other, and the transfer electrodes of the respective registers are formed in the registers. When the above-mentioned register transfer is performed, the level of the adjacent transfer electrodes changes at the same time or the charge transfer level becomes the same at the same time. When the charge is transferred between the registers by driving with a different pulse signal having no charge, the potential of at least the transfer electrode on the side receiving the charge is made deeper than the potential of the transfer electrode on the side sending the charge. Transfer device.