JPH11331713A - Image-pickup device and image-pickup system using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain satisfactory performance without lowering resolution, even when plural pixels share one amplifying means by adjusting the pitch of photodetection parts in the center part of a device which processes plural pixel signals to equal pitch in at least one of the horizontal and vertical directions. SOLUTION: Unit cells are arranged repeatedly in rows and columns by a size of four pixels. Photodiode incident light is converted into electric charges, and stored electric charges are transferred and carried to a MOS amplifier which is an amplifying means, whose output current is taken out of a pixel array by a vertical signal line. A common pixel amplifying part 12 is arranged in the center among four pixels and four photoelectric conversion parts (a11, a12, a21, and a22) are arranged to surround the amplification part. A light-proof parts 15 are placed at the positions, which are center-symmetrical with respect to respective pixel areas where the amplifying part 12 occupies, and the four photoelectric conversion part (a11 to a22) are arranged longitudinally and laterally at equal intervals (a). Consequently, moire fringes are prevented from being formed, and the numerical aperture is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to an image pickup apparatus for picking up an image and an image pickup system using the same.

[0002]

2. Description of the Related Art Conventionally, in an image pickup apparatus having a gain cell or an APS, a BJT or a MOSFE is used for a pixel amplifier.
Some use T, JFET, and the like.

[0003] In these methods, signal charges accumulated in a photodiode as a photoelectric conversion element are amplified by respective methods and read out as image information. Since the means for amplifying the signal charge exists in each pixel, it is called a gain cell or APS.

Since the APS has an amplifying unit (amplifier) and its control unit in the pixel, the ratio of the photoelectric conversion unit to the pixel (area ratio) or the ratio of the light incident area to the pixel (opening ratio) is small. It tends to be. Therefore, the dynamic range, sensitivity, S / N ratio, etc. of the imaging device may be reduced.

When one amplifier is provided for one pixel as shown in FIG. 22-b, the aperture ratio decreases. Area ratio by amplification means,
As a method for preventing a decrease in aperture ratio, for example, Japanese Patent Application Laid-Open
As disclosed in Japanese Unexamined Patent Application Publication No. 0879 or Japanese Unexamined Patent Application Publication No. 9-46596, a method of sharing one amplifying means by a plurality of pixels has been proposed.

FIG. 24 is a diagram showing the pixel configuration. In FIG. 24, PD1 to PD4 are photodiodes serving as photoelectric conversion units, and MTX1 to MTX4 are photodiodes PD
Transfer MO for transferring signal charges stored in 1 to PD4
S transistor, MRES: reset MOS transistor, MSF, MSEL: amplification means (source follower)
And MSEL is a selection switch for selecting a pixel.

[0007]

However, Japanese Patent Application Laid-Open No. 63-100879 or Japanese Patent Application Laid-Open No. 9-4659 discloses the above.
Japanese Patent Application Laid-Open No. H06-13964 does not disclose a specific arrangement in the case where one pixel is shared by a plurality of pixels.

[0008] Further, there is no specific disclosure even if the shared part is not the above-described amplifying means but performs other processing.

Therefore, an object of the present invention is to provide an image pickup apparatus which can obtain good performance without lowering the resolution even when a plurality of pixels share a common circuit such as one amplifying means. I do.

Another object of the present invention is to provide an image pickup apparatus having a noise removing means suitably used for the above image pickup apparatus.

Still another object of the present invention is to provide an image pickup system using the above image pickup device in a sensor section.

[0012]

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems.

Therefore, in an image pickup apparatus in which a plurality of unit cells each including a plurality of pixels and a common circuit for processing signals from the plurality of pixels are arranged, at least a pitch between light receiving portions at a central portion of the image pickup apparatus. An image pickup apparatus is provided, which comprises an adjusting means for adjusting the pitch at least in one direction of a vertical direction or a horizontal direction.

Further, in an image pickup apparatus in which a plurality of unit cells each including a plurality of pixels and a common circuit for processing signals from the plurality of pixels are arranged, an image signal from the plurality of pixels is output at the same timing. Provided is an imaging apparatus including a noise removing unit that removes a noise signal.

Further, an image pickup system comprising the image pickup apparatus described above, a lens for forming an image of light on the image pickup apparatus, and a signal processing circuit for processing an output signal from the image pickup apparatus. provide.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Prior to the description of the embodiments of the present invention, the technical background leading to the present invention will be described.

The present inventors have disclosed the above-mentioned JP-A-63-1.
A pixel layout in an image pickup apparatus, such as that disclosed in Japanese Patent Application Laid-Open No. 00879 or Japanese Patent Application Laid-Open No. 9-46596, in which a plurality of pixels share a common circuit such as one amplifying means (amplifier) was studied.

FIG. 22A shows a pixel layout diagram of an example of the image pickup apparatus when the number of pixels is four for the common circuit.

This embodiment is an example in which amplifying means is shared every two rows and two columns of pixels, and four photodiodes 173 (a11,
a12, a21, a22), the amplification means 174 is arranged. Here, 171 is a repeating unit cell for two rows,
172 indicates a repeating unit cell for two columns.

FIG. 23 shows a specific pixel pattern layout diagram.

The image pickup device is a CMOS sensor.

In FIG. 23, reference numeral 181 denotes a unit cell (dotted line area in the figure) of the above-described repetition, which is repeatedly arranged in the row and column directions with a size of four pixels. Light incident on the photodiodes 182a, 182b, 182c, 182d is converted into electrons, which are accumulated charges, and is accumulated in the photodiodes 182a to 182d. The accumulated charges are transferred to the floating diffusion 185 by the transfer gates 183a to 183d, and are transferred to the input gate 186 of the MOS amplifier as the amplifying means. The current flowing through the MOS amplifier is modulated by the accumulated charge, and the output current is taken out of the pixel array by the vertical signal line 187.

The X-axis of the image pickup device (two-dimensional pixel array)
Y addressing is performed on the vertical signal line 187 and the scanning line 18.
8a to 8d, which are performed by the row selection line 190. In addition to these wirings, a power supply VDD wiring 191 is arranged vertically, and a floating diffusion 185 and a reset line 192 for resetting the input gate 186 to a predetermined voltage are arranged horizontally.

The wirings 188 to 192 are arranged above the wirings in the cell, so that the basic dimensions are correspondingly reduced. Since these six opaque wirings 188 to 192 are optically insensitive areas, the amplifying means distributed and arranged are placed below these wirings 188 to 192. Therefore, it is conceivable to dispose the photodiodes so as to be displaced in the square direction of the unit cell 181.

However, as is clear from FIG. 22 (a), such an arrangement does not provide a uniform pitch of the photoelectric conversion units, so that the area (light receiving unit) of the light in each pixel that is related to the light. The intervals are not equal, causing the following problem.

That is, an array of the same color that is not equal pitch is
Since the spatial frequency and the resolution are partially unequal, defects such as a decrease in resolution and moiré fringes occur. In addition, the occurrence of moiré fringes is a very serious problem, and such an imaging device cannot be practically used as a product. This is also true when the number of pixels constituting the unit cell is other than four.

The present inventors have further studied in view of the above points, and as a result, in an APS having amplifying means dispersed in a plurality of pixels, the APS has a constant photoelectric conversion unit pitch. The distance between the light receiving portions is equalized, and the imaging device capable of preventing a decrease in resolution and generation of moire fringes, improving an aperture ratio and the like, and obtaining good performance has been found.

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

FIG. 1 is a diagram showing an example in which pixels in two rows and two columns share the amplifying means 12.

In FIG. 1, the shared amplifying means 12 is arranged at the center of the four pixels, and the four photoelectric conversion units (a
11, a12, a21, a22) are arranged so as to surround the amplifying means 12.

Further, a light-shielding portion 15 exists at a position symmetrical with the center of each pixel occupied by the amplification means 12. Therefore, the center of gravity of the photoelectric conversion unit 11 in each pixel exists at the center of each pixel. Thus, the four photoelectric conversion units (a11 to a22) can be arranged at equal intervals a in the vertical and horizontal directions.

In FIG. 2, the shared amplifying means 22
Are arranged at the center in the horizontal direction of the four pixels, and four photoelectric conversion units 21 (a11, a12, a21, a22) are arranged so as to sandwich the amplifying unit 22.

Further, a light-shielding portion 25 exists at a position symmetrical with the center of each pixel occupied by the amplifying means 12. Therefore, the center of gravity of the photoelectric conversion unit 11 in each pixel exists at the center of each pixel. Thus, the four photoelectric conversion units (a11 to a22) can be arranged at equal intervals a in the vertical and horizontal directions.

The above-described embodiment shown in FIG. 2 is exactly the same even if the horizontal and vertical directions are exchanged.

In FIG. 3, G pixels having the highest resolution are arranged at the upper left and lower right of the repeating unit cell 30 composed of four pixels. In the G pixel, the cell 30
The light-shielding portion 35 exists at a position symmetrical with respect to the area occupied by the amplifying means 32 disposed at the center of the light-shielding section. Therefore, the center of gravity of the photoelectric conversion unit 31 in the G pixel exists at the center of the G pixel. Thus, the photoelectric conversion units a11 and a22 of the G pixel can be arranged at equal intervals a in the vertical and horizontal directions.

The R pixel is located at the upper right of the cell 30, and the B pixel is located at the lower left of the cell 30. These are G
Although it does not have a specially considered light shielding part like pixels,
Since the number of arrangements in the unit cells 30 is 1, the unit cells 30 can be arranged at equal intervals at the interval 2a.

FIG. 4 shows a variation of the embodiment shown in FIG. 3, in which the area occupied by the amplifying means and the light shielding portion in the G pixel is reduced.

The present inventors have also found a signal readout circuit used for noise removal that is effective in an image pickup apparatus in which one pixel is shared by a plurality of pixels as described above.

In the embodiment described above, the amplifying means is disclosed as a part shared by a plurality of pixels, but the shared part is not limited to the amplifying means.

[0040]

Embodiments of the present invention will be described below in detail with reference to the drawings.

First, FIG. 6 shows a block diagram of an imaging system using the imaging device according to the present invention. As shown in the figure, the image light incident through the optical system 71 forms an image on the CMOS sensor 72. The optical information is converted into an electric signal by the pixel array arranged on the CMOS sensor 72. The electric signal is subjected to signal conversion processing by a signal processing circuit 73 by a predetermined method and output. The signal that has been subjected to the signal processing is recorded by a recording system and a communication system 74 by an information recording device, or information is transferred.
The recorded or transferred signal is reproduced by the reproduction system 77. The CMOS sensor 72 and the signal processing circuit 73 are controlled by the timing control circuit 75, and the optical system 71, the timing control circuit 75, the recording / communication system 74, and the reproduction system 7
7 is controlled by the system control circuit 76.

Embodiment 1 First, Embodiment 1 will be described.

FIG. 5 shows a circuit diagram of one pixel of the CMOS sensor.

In FIG. 5, a11 to a22 are photodiodes serving as photoelectric conversion units, and MTX1 to 4 are photodiodes a.
A transfer MOS transistor for transferring the signal charges stored in 11 to a22 to a floating diffusion (hereinafter referred to as FD), MRES is a reset MOS transistor for resetting the FD, and MSF and MSEL are MOS transistors constituting a source follower circuit. And
MSEL is a selection switch for selecting a pixel.

FIG. 7 shows a specific pattern layout of the pixel array section of the CMOS sensor of this embodiment.

The CMOS sensor shown in FIG. 8 is formed on an edge crystal substrate with a layout rule of 0.4 μm, the size of a pixel is 8 μm square, and a source follower amplifier as amplifying means has a 2 × 2 matrix. Shared by 4 pixels. Therefore, the size of the repeating unit cell 81 shown by the dotted line area in the figure is 16 μm × 16 μm square, and a two-dimensional array is formed.

The photodiodes 82a, which are photoelectric conversion units,
Reference numerals 82b, 82c, and 82d are formed obliquely at the center of each pixel, and their shapes are substantially rotationally symmetric and mirror image symmetrical in up, down, left, and right directions. The center of gravity g of the photodiode is designed to be the same for each pixel. Reference numeral 95 denotes a light shielding unit.

Reference numeral 88-a denotes a scanning line for controlling the upper left transfer gate 83-a, reference numeral 90 denotes a row selection line, and reference numeral 92 denotes a MOS gate 9.
3 is a reset line for controlling the reset line 3.

The signal charges stored in the photodiodes 82a to 82d are guided to the FD 85 through the transfer gates 83a to 83d. The MOS size of the gates 83a to 83d is L = 0.4
μm, W = 1.0 μm (L indicates a channel length, and W indicates a channel width).

The FD 85 is connected to an input gate 86 of a source follower by an Al wiring having a width of 0.4 μm.
The signal charge transferred to the FD 85 modulates the voltage of the input gate 85. The size of the MOS of the input gate 86 is L =
0.8 μm, W = 1.0 μm, and the sum of the capacitances of the FD 85 and the input gate 86 is about 5 fF. Q = because it is CV, input by the accumulation of 10 ⁵ electrons gates 86
Will change by 3.2V.

The current flowing from the V _DD terminal 91 is modulated by the input gate 86 and flows out to the vertical signal line 87.
The current flowing out to the vertical signal line 87 is subjected to signal processing by a signal processing circuit (not shown), and finally becomes image information.

Thereafter, the photodiodes 82a to 82d, FD
85, the potential of the input gate 86 to the V _DD predetermined value and opening the MOS gate 83 connected to the reset line 82, (also open transfer gate 83a~d this time)
Photodiodes 82a-d, FD85, input gate 86
Is shorted to the V _DD terminal.

Thereafter, by closing the transfer gates 83a to 83d, charge accumulation in the photodiodes 82a to 82d starts again.

It should be noted here that all the wirings 88a to 88d, 90, and 92 penetrating in the horizontal direction are transparent conductors of ITO (Indium Tin Oxi) having a thickness of 1500 mm.
de), among the wiring portions,
Since light is transmitted through the photodiodes 82a to 82d, the center of gravity g of the photodiode coincides with the center of gravity of the light sensing area (light receiving portion).

According to the present embodiment, it is possible to provide a CMOS sensor having a relatively high area ratio and a high aperture ratio having the same pixel pitch.

(Embodiment 2) A second embodiment will be described.

FIG. 8 shows a specific pattern layout of the image pickup apparatus according to the second embodiment of the present invention.

In FIG. 9, 102a to 102d are photodiodes, 103a to 103d are transfer gates, 105 is an FD, 106
Is an input gate of a source follower, 107 is a vertical signal line,
108a to 108d are scanning lines, 110 is a row selection line, 112 is M
A reset line for controlling the OS gate 113.

In this embodiment, the wiring 10 running in the horizontal direction is used.
8a-d, 110 and 112 run across the center of each pixel three by three.
Even if the metal wiring obstructs the light incident on 2a to 2d, the center of gravity g of the light sensing area does not move, and thus coincides with the center of the pixel.

According to this embodiment, since a normal (opaque) metal having a small electric resistance can be used, the time constant of the horizontal wiring can be improved, and a higher-speed imaging device can be provided.

In the above embodiment, since the portion under the light-shielding film is effectively used, a photodiode as a photoelectric conversion portion is formed up to the portion under the light-shielding film as shown in FIG.
It is also possible to function as a charge storage unit.

(Embodiment 3) A third embodiment will be described.

In the second embodiment described above, since the light crosses the center of the pixel having the highest light focusing efficiency, there is a concern that the sensitivity of the image pickup apparatus may be reduced. FIG. 1 shows a further improved embodiment.
0 is shown.

In this embodiment, the transfer gates 123a to 123a
d, FD125, source follower input gate 126,
Since all of the reset MOS gates 133 are formed under horizontal wirings (scanning lines 128a to 128d, row selection line 130, reset line 132), the photodiodes 12
2a to d and the opening thereof can be maximized. In addition, the opening exists continuously at the center of each pixel. The light-shielding portions are formed in horizontal and vertical wiring portions.

In this embodiment, since the source follower and the reset MOS transistor, which are the amplifying means, are divided and arranged in the horizontal direction around each pixel, they can be compactly arranged below the horizontal wiring. It has become.

Further, since there is still an unused space below the wiring of the upper right pixel, for example,
It is also possible to add a new configuration.

According to the present embodiment, a large dynamic range and high sensitivity imaging device can be provided because the photodiode area and aperture ratio can be made large. Further, even if the size of the opening portion of the photodiode becomes approximately equal to the wavelength of light in the future as miniaturization progresses, there is little fear that light will not enter, and the performance can be exhibited for a long time.

In the above embodiment, the amplifying means is arranged at the center of the unit cell, and the center of gravity of the light sensing area coincides with the center of the pixel. However, the present invention is not limited to this.
A configuration in which the openings are translationally symmetric as shown in FIG. 11 may be used.

That is, since the openings are translationally symmetric, the light sensing areas have the same pitch.

(Embodiment 4) A fourth embodiment will be described.

FIG. 12 shows a specific pattern layout of an image pickup apparatus according to the fourth embodiment.

In this embodiment, the positions of the colors to be used are determined. The upper left and lower right are the G pixels which most influence the luminance, the upper right is the R pixel, and the lower left is the B pixel.

In this embodiment, the amplifying means and others are arranged so that the photodiodes 142a and 142d of the G pixels have the maximum area and the maximum aperture.

Further, since the center of gravity g of the light sensing area in the G pixel coincides with the center of each pixel, equal pitch characteristics of the G pixels are ensured.

According to the present embodiment, it is possible to provide a high-sensitivity imaging device.

In the human eye, the luminance resolution is higher than the color resolution, and a characteristic similar to a state where the color disappears in a dark place and only the light and dark of the object can be seen is realized. Can be done.

(Embodiment 5) A fifth embodiment will be described.

FIG. 13 shows a fourth embodiment of the present invention.

In FIG. 13, an on-chip lens 202 is formed in each pixel of the unit cell 201. Light from the outside is condensed by the on-chip lens and enters the opening 203. Here 204 is
This is a light receiving unit focused by the on-chip lens.

Here, by adjusting the on-chip lens, the position of the light receiving section can be given a degree of freedom.

For this reason, when amplifying means shared by a plurality of pixels is used, even if it is not possible to form photodiodes as photoelectric conversion units at equal pitches, by adjusting the on-chip lens, each light receiving unit can be adjusted. It is possible to make the intervals equal in pitch.

When the imaging lens used in the imaging device is not telecentric, the light incident on the sensor chip has different incident angles (optical axes) between the center and the outer periphery of the chip. For this reason, in the first or second embodiment, by setting the openings at unequal pitch only in the outer peripheral portion, the light sensing region over the entire sensor chip can be at equal pitch.

As described above, in the first to fourth embodiments, the light sensing area (light receiving section) is set at the same pitch by adjusting the light shielding section, which is an optical member. Further, in the fifth embodiment, the light sensing area (light receiving section) is set at the same pitch by adjusting the lens which is an optical member.

(Embodiment 6) A sixth embodiment will be described.

In this embodiment, an imaging apparatus according to the present invention including a signal processing circuit will be described. FIG. 14 shows an equivalent circuit diagram of an imaging device including the signal processing circuit unit of the present embodiment.

FIG. 15 is a timing chart.

Clock φ representing vertical blanking period
Vertical scanning is started by V (n). First, the reset line φTX _RO of the first row is set in the horizontal blanking period (φHBL
High), and then the second and third rows are performed similarly. Thus, the pixels in each row are reset to the reset potential V _DD . (FIG. 6)

During each horizontal period, as shown in FIG.
Wherein the the period T ₁ φRv high vertical signal line 157
Is turned on, the vertical signal line 157 is reset. Along with φTN, φT
Each gate Tr162 is turned on by S1 and φTS2 high, and the wiring and the storage capacitor 1 before the signal reading Tr164 are turned on.
63 conducts with the vertical signal line and is similarly reset. As a result, the charges stored in the storage capacitor 163 and the like are removed. Then the reset line in a period T ₂ phi
When TX _{RO is} high, the floating gate, which is the input gate of the source follower amplifier in the pixel, is reset to _VDD . Then in the period T _3, the φL high ground Tr161 to be connected to the signal line 157 is turned on, the signal line 157 is grounded. At the same time, in order to connect a storage capacitor CTN 163 for storing a noise component to the signal line 57, φTN is set high and the gate Tr16
Turn on 2. At this time, the row selection line φSO is high, and the potential of the floating gate (〜V _DD )
Flows from the V _DD terminal toward the CTN, the storage capacitor CTN holds the charge of the noise component.

[0089] odd column transfer gate in the period T ₄ by the odd column scanning line .phi.TX _OOO high then is in the pixel is turned on,
The accumulated charge corresponding to the image light in the photodiode a11 is transferred to the floating gate. At this time, the capacitance hanging from the signal line 157 is not CTN for noise but CTS1. Similarly, the charge of the signal 1 component in the odd-numbered column corresponding to a11 is stored in the storage capacitor CTS.
It is held at 1.

[0090] only the signal line 157 is reset by the next period T ₅ in φRV high. Other circuits are φSO, φ
Since TN to φTS2 are low, they are not affected by the reset, and the state is maintained.

[0091] Next, signal .phi.TX _Ro applied to the reset line 62 between the period T ₅ and the period T ₆ is input gates in the pixel at a high level is reset to V _DD.

[0092] period in T ₆ now accumulated charge of the photodiode a ₁₂ is transferred by the scanning line .phi.TX _OEO high, similarly to the signal charge is held in the storage capacitor CTS2.

[0093] In this way, noise component of one row, the photodiode a ₁₁ signal components, charges of the photodiode a ₁₂ signal components are stored in each column in CTN, CTS1, CTS2.

[0094] Te is at the period T _7, CTN~CTS of each column
In order to sequentially transfer the electric charges accumulated in 2 to the amplification amplifier 166, the horizontal scanning pulse φHc is sequentially turned high for each column to turn on the gate Tr164 arranged for each column, and for each of the columns, The storage capacitors CTN to CTS2 and the amplifier are made conductive. The noise component that has passed through the amplifier, the signal of the photodiode a _11, the signal component of the photodiode a ₁₂ comprises a component S1, noise components run over the signal component of the photodiode a ₁₁ by the differential amplifier 167, the photodiode a A component S2 obtained by subtracting a noise component from the _twelve signal components is finally output.

The period 7 is also a period in which the photoelectric charge accumulation of the photodiode is performed.

[0096] Further, .phi.TX in the case of obtaining a component obtained by subtracting the noise component from the signal components from the photodiode a _21, a ₂₂ also, this time, .phi.TX _ooo, instead of .phi.TX _{OEO
The same} operation as described above can be performed except that _ooe and φTX _oee are made high.

(Embodiment 7) Embodiment 7 will be described.

FIG. 16 shows an equivalent circuit diagram of an image pickup apparatus including the signal processing circuit section of this embodiment.

In this embodiment, four storage capacitors CTS1 to CTS463 for signal storage are provided, and it is possible to store different signal information in each of the capacitors 63. More specifically, CTS1 has pixel a11,
The signal charges of the pixels 22 can be stored in the CTS 4. Accordingly, the signal processing after the amplification amplifier 66 is improved at half the speed, and the signal processing of the amplification amplifier 66, the differential amplifier 67, and the signal processing system of the rear plate (not shown) is reduced by half compared with the sixth embodiment. Better with speed. The speed of the elements used in the circuit can be reduced by that much,
Inexpensive elements and circuits with low performance can be used, and cost reduction of the entire system can be expected.

Also, the electric charge stored in the storage capacitor does not need to be a direct output from each photodiode.
By devising the clocks of the transfer gate and the reset gate associated with each pixel, it is possible to add the signal charges of the photodiodes as is well known. For example, it is possible to extract signals such as G optical information of the pixel a11 in CTS1, G optical information of the pixel a22 in CTS2, and R + B optical information of the pixel a12 + a21 in CT3. In this embodiment, the configuration is such that a smart sensor that uses each pixel more intelligently can sufficiently exert its power.

In the sixth and seventh embodiments described above, it is possible to remove noise due to variations in the characteristics of the amplifying means for each unit cell.

(Eighth Embodiment) An eighth embodiment will be described.

Referring to FIG. 17, the timing when this embodiment is driven in a non-interlace manner will be described.

In the horizontal blanking period (HBLK), the transfer of the signal photoelectrically converted by the pixel and the resetting operation to the initial state of the photoelectric conversion are performed.

[0105] In the period T _1, to reset the vertical signal line at pulse .phi.V, with the removal of the signal line of the residual charge, pulse φTN1, φTN2, φTS1, one o'clock in φTS2 storage memory CTN1, CTN2, CTS1, CT
The residual charges on S2 are removed.

In the period T ₂ , the first pixel row (a ₁₁ ,
a ₁₂ ,... a _1n ), before the transfer of the odd-numbered photoelectric conversion signals, the gate portion of the common amplifier is reset with the pulse φTX _RO to remove residual charges. After the removal, reset noise remains in the gate portion.

[0107] In the period T _3, a period for transferring the offset voltage of the common amplifier reset noise in the period T ₂ to the memory CTU1. The output of the common amplifier is connected to the vertical signal line by the pulse φSO, the load MOS Tr is turned on by the pulse φL to make the common amplifier operate, and the memory is connected by the pulse φTN1. It is stored in the memory as noise (N).

In the period T ₄ , the odd number (a ₁₁ , a ₁₃ ,.
.. A _1n ) during which the photoelectric conversion signal is transferred to the memory CTS1. Pulses .phi.L, .phi.TS1, and .phi.SO bring the common amplifier to the memory into a conductive state.

[0109] The photoelectric conversion signals a pulse .phi.TX _oo is transferred from the light receiving portion to the gate of the common amplifier. So that the photoelectric conversion signal to the reset noise in the period T ₂ is added to the gate at this time. This gate voltage is superimposed on the offset voltage of the common amplifier, and the signal (S
+ N).

In the periods T _{5 to} T ₈ , during this period, driving for transferring the even-numbered (a ₁₂ , a ₁₄ ,... A _1n-1 ) photoelectric conversion signals to the memory T _S2 is performed. The basic operation described above of the T ₁ ~
Is the same as the period T _4. The difference is φTX _oo → φT
_Xoe , φT _N1 → φT _N2 , φT _S1 → φT _S2 pulse control.

[0111] In the period T _9, to terminate the basic operation of the transfer of the reset noise and the photoelectric conversion signal by removing the residual charge between the common amplifier and the transfer MOS and the vertical signal line.

With the above-described driving, noise N1,
N2, signals S1 + N1 and S2 + N2 are stored.
These noise and signal pulses φH1 from the horizontal shift register T ₁₀ period, it is transferred in the horizontal output lines in .phi.H2. Output amplifier A1 subtracts (S1 + N1) -N1 and outputs signal S1, and output amplifier A2 subtracts (S2 + N2) -N2 and outputs signal S2.

This means that only the photoelectric conversion signals of the pixel rows (a ₁₁ ... A _1n ) have been obtained. In the accumulation of the pixel rows, the photoelectric conversion is started when the photoelectric conversion signal is transferred to the gate section in the periods T ₄ and T ₈ .

In the next horizontal blanking period, the operation of the second pixel row is performed in the same manner as the first row. When the operation of the second pixel row ends, the common amplifier in units of four pixels becomes
It becomes non-conductive until after one vertical period in which the next operation is performed.

In FIG. 18, when two rows are driven simultaneously, a memory (CT _N1 , CT _S1 , CT _S2 ) and an output differential amplifier (A
1, A2) can be easily achieved by adding another series. That is, the non-interlaced driving is used to drive one row to the pixel row every 1H, but this may be performed for two pixel rows within the 1H period.

FIG. 6 is a schematic diagram of the vertical timing.

In one vertical period, the operation in the horizontal period described above and the driving for pixels in the vertical direction are sequentially performed. The vertical shift register outputs drive pulses φTX _oo , φTX _oe , φT every 1H.
X _RO and φSo pulses are output for each row.

As described above, in the eighth embodiment, not only the noise due to the variation in the characteristics of the amplifying means as in the above-described sixth and seventh embodiments, but also the reset noise can be removed. Becomes

(Embodiment 9) Embodiment 9 will be described.

The present invention can be used not only for a general CMOS sensor as shown in FIG. 24 but also for ISSCC98 / SESS: ON11 / IMAGE shown in FIG.
SEMSORS / PAPER FA11.8pp182
Can be applied to the image sensor disclosed in the above.

At this time, as a configuration of the amplifier shared by the four pixels, for example, a circuit as shown in FIG. 20 can be considered.

(Embodiment 10) Embodiment 10 will be described.

In this embodiment, a common circuit in which an additional function is provided for a common amplifier of a pixel will be described.

FIG. 21 shows an embodiment of the common circuit.

A memory circuit, a differential amplifier, and a comparator are provided after the common amplifier. The noise described in the above embodiment is temporarily stored in the memory, and the signal (S−
N) is transferred and only the signal (S) is obtained by taking the difference between them. This signal is output to a vertical signal line. Alternatively, depending on the purpose, binarization can be performed by a comparator at the subsequent stage.

If the comparator is an AD converter, an AD output can be obtained. The AD output may be either a serial output or a parallel output, and the circuit configuration may be changed according to the purpose.

[0127]

As described above, according to the present invention,
It is possible to realize a high-yield imaging device having a large aperture ratio, high sensitivity, and a built-in multi-function without causing a reduction in performance such as a decrease in resolution and generation of moire fringes.

[Brief description of the drawings]

FIG. 1 is a diagram showing a pixel section layout of the present invention.

FIG. 2 is a diagram illustrating a layout of a pixel unit according to the present invention.

FIG. 3 is a diagram illustrating a layout of a pixel unit according to the present invention.

FIG. 4 is a diagram showing a layout of a pixel unit according to the present invention.

FIG. 5 is a circuit configuration diagram of a unit cell of the CMOS sensor.

FIG. 6 is a block diagram of an imaging system using the imaging device of the present invention.

FIG. 7 is a pattern layout diagram of one embodiment of the present invention.

FIG. 8 is a pattern layout diagram of one embodiment of the present invention.

FIG. 9 is a diagram illustrating an embodiment of the present invention.

FIG. 10 is a pattern layout diagram of one embodiment of the present invention.

FIG. 11 is a diagram illustrating an example of the present invention.

FIG. 12 is a pattern layout diagram of one embodiment of the present invention.

FIG. 13 is a diagram illustrating an embodiment of the present invention.

FIG. 14 is a signal processing circuit diagram according to one embodiment of the present invention.

FIG. 15 is a timing chart of one embodiment of the present invention.

FIG. 16 is a signal processing circuit diagram according to one embodiment of the present invention.

FIG. 17 is a signal processing circuit diagram of one embodiment of the present invention.

FIG. 18 is a timing chart of one embodiment of the present invention.

FIG. 19 is a timing chart of one embodiment of the present invention.

FIG. 20 is a diagram illustrating an example of the present invention.

FIG. 21 is a diagram illustrating an example of the present invention.

FIG. 22 is a layout diagram of a pixel portion of the imaging device.

FIG. 23 is a pattern layout diagram of the imaging device of FIG. 22;

FIG. 24 shows a circuit configuration diagram of a unit cell of a CMOS sensor.

FIG. 25 is a circuit configuration diagram of a pixel portion of a conventional CMOS sensor.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 photoelectric conversion part 12 common pixel amplifier part 15 light shielding part 21 photoelectric conversion part 22 common pixel amplifier part 25 light shielding part 31 photoelectric conversion part 32 common pixel amplifier part 35 light shielding part 202 on-chip lens

Claims (33)

[Claims] 1. An imaging device in which a plurality of unit cells each including a plurality of pixels and a common circuit for processing signals from the plurality of pixels are arranged, wherein at least a pitch between light receiving portions at a central portion of the imaging device. An image pickup apparatus, comprising: adjusting means for adjusting the pitch at least in one direction of a vertical direction or a horizontal direction. 2. The image forming apparatus according to claim 1, wherein the adjusting unit is configured to cancel an unequal pitch in at least one of a horizontal direction and a vertical direction of a light receiving unit at least in a central portion of the imaging device, which is caused by the common circuit. An imaging device, which is an optical member. 3. The imaging device according to claim 2, wherein the optical member is a light shielding film. 4. The imaging device according to claim 3, wherein the common circuit is arranged at a center of a unit cell. 5. The imaging device according to claim 4, wherein the light shielding film is disposed between adjacent unit cells. 6. The imaging apparatus according to claim 5, wherein the light-shielding film is disposed at a position that is at least line-symmetric with respect to a horizontal or vertical center line of the unit cell. 7. The imaging device according to claim 1, wherein the openings are respectively translationally symmetric. 8. The imaging device according to claim 2, wherein the optical member is an on-chip lens. 9. The image forming apparatus according to claim 1, wherein the apertures are formed at unequal pitches in order to make the light receiving portions in the peripheral portion of the imaging device have equal pitches. Characteristic imaging device. 10. The imaging device according to claim 1, wherein the center of gravity of the light receiving unit in each pixel coincides with the center of each pixel. 11. The method according to claim 1, wherein
In the paragraph, the common circuit is an amplifier. 12. The imaging apparatus according to claim 11, wherein the amplifier has an amplifying unit that amplifies signals from a plurality of pixels in the unit cell and a reset unit that resets the unit cell. 13. The method according to claim 11, wherein
An image pickup apparatus, wherein wiring is provided so that the center of gravity of the light receiving unit in each pixel and the center of the pixel in the unit cell coincide with each other. 14. The method according to claim 11, wherein
An imaging device, wherein the unit cell has a wiring penetrating in a horizontal direction, and the wiring is a transparent conductor that transmits light. 15. The method according to claim 11, wherein
The imaging device according to claim 1, wherein the unit cell includes a wiring penetrating in a horizontal direction, and the wiring crosses a center of the pixel. 16. The method according to claim 11, wherein
An imaging apparatus, wherein the unit cell has a wiring penetrating in a horizontal direction, and an element group constituting the unit cell is arranged below the wiring. 17. The method according to claim 11, wherein
An imaging apparatus, wherein the unit cell has a wiring penetrating in a horizontal direction, the wirings are divided into two groups, and each of the wirings penetrates a peripheral portion of each pixel by the same number. 18. The imaging device according to claim 17, wherein the unit cell has at least an amplifying unit and a resetting unit, and the amplifying unit and the resetting unit are arranged below separate groups of wirings. apparatus. 19. An image pickup apparatus in which a plurality of unit cells each including a plurality of pixels and a common circuit for processing signals from the plurality of pixels are arranged, and a plurality of pixels selected under a certain condition receive light. An image pickup apparatus, comprising: an adjusting unit for providing a uniform pitch at least in a vertical direction or a horizontal direction at least in a central portion of the image pickup element between the units. 20. The device according to claim 19, wherein the common circuit is disposed at a central portion of the unit cell, and a ratio of the common circuit in a plurality of pixels selected under the predetermined condition is the same. An imaging apparatus characterized in that the ratio is smaller than the ratio of a common circuit in a pixel other than a plurality of pixels selected under a certain condition. 21. The method according to claim 19, wherein
The image pickup apparatus, wherein the plurality of pixels selected under the certain condition are pixels to which a color filter mainly determining luminance is attached. 22. An imaging apparatus according to claim 19, wherein a color mainly determining luminance is green (G). 23. The imaging apparatus according to claim 19, wherein said adjusting means is a light-shielding film, and said light-shielding film is symmetric with respect to a center of said unit cell. 24. An imaging apparatus in which a plurality of unit cells each including a plurality of pixels and a common circuit for processing signals from the plurality of pixels are arranged, wherein an image signal from the plurality of pixels is output at the same timing. An imaging device comprising a noise removing unit for removing a noise signal. 25. An image pickup apparatus in which a plurality of unit cells each including a plurality of pixels and a common circuit for processing signals from the plurality of pixels are arranged, wherein an image signal from the plurality of pixels in the unit cells is provided. A plurality of image signal accumulators, a plurality of image signal accumulators, and a plurality of image signal accumulators for accumulating characteristic variation signals in the common circuit for compensating characteristic variations in the common circuit. A difference means for subtracting a signal from the variation signal storage means from a signal from the means. 26. An image pickup device in which a plurality of unit cells each including a plurality of pixels and a common circuit for processing signals from the plurality of pixels are arranged, wherein a first signal from the plurality of pixels in the unit cells is provided. A plurality of first accumulating means for accumulating a second signal, and a plurality of second accumulating means for accumulating a second signal from the plurality of pixels.
An image pickup apparatus comprising: an accumulating unit; and a plurality of difference units for subtracting signals from the plurality of second accumulating units from signals from the plurality of first accumulating units. 27. The imaging apparatus according to claim 26, wherein the first signal is an image signal, and the second signal is a noise signal. 28. An imaging device in which a plurality of unit cells each including a plurality of pixels and a common circuit for processing signals from the plurality of pixels are arranged, wherein the common circuit reads a signal from the unit cell. An imaging apparatus, comprising: timing processing means for outputting a plurality of processing signals from the unit cell by changing timing. 29. The imaging apparatus according to claim 28, wherein the plurality of processing signals are a signal from a single pixel and an addition signal of a plurality of pixels. 30. The common circuit according to claim 19, wherein the common circuit is an amplifier. 31. The imaging apparatus according to claim 30, wherein the amplifier includes an amplifying unit that amplifies signals from a plurality of pixels in the unit cell and a reset unit that resets the unit cell. 32. Claims 1 to 10 and 1
32. The imaging apparatus according to claim 9, wherein the common circuit includes digital signal conversion means for converting signals from a plurality of pixels in the unit cell into digital signals. 33. Any one of claims 1 to 32
An imaging system comprising: the imaging device according to any one of the preceding items, a lens that forms light on the imaging device, and a signal processing circuit that processes an output signal from the imaging device.