JPH04364679A - Solid-state image pickup device - Google Patents

Abstract

PURPOSE:To realize the solid-state image pickup device having a large dynamic range by using a photoelectric conversion output signal in a nonlinear region as input information together with a photoelectric conversion output signal of a linear region. CONSTITUTION:An output signal of an output amplifier 6 having a nu characteristic and comprising a linear region and a nonlinear region is subjected to low frequency noise reduction through a correlation duplicate sampling(CDS) circuit 8 and the result is converted into a digital signal by an A/D converter 9. The digital signal is inputted to an arithmetic unit (ALU) 10m in which a signal belonging to the nonlinear region is converted into a linear signal. Thus, the vertical overflow drain blooming suppression system is employed for a picture element section in this way to cause the nu characteristic to a signal charge stored in an emitter of a bipolar transistor(TR) 1 and a photoelectric conversion output signal in the nonlinear region is used as input information to realize the solid-state image pickup device having a large dynamic range of 80-100dB or over.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a solid-state imaging device having a plurality of photoelectric conversion sections whose photoelectric conversion output signal characteristics are in a linear region and a nonlinear region.

0002

2. Description of the Related Art In the prior art, a photoelectric conversion output signal in a solid-state imaging device is used as input information only in a linear region. For example, ``A 1 megapixel IL-CCD image sensor with a progressive scan'' by E.G. Stevens et al.
Antiblooming Control and Lag-Free Operation” SPI,
1242, pp. 206-215, 1990 (E.G.
Stevens, et al. , “A 1-maga
pixel IL-CCD image sensor
with a progressive scan,
antiblooming control and
lag-free operation,” SPI
E vol. 1242, pp. 206-215,19
90. ) has Vertical Overflow
A solid-state image sensor using the Drain (VOD) (vertical, overflow, drain) blooming suppression method has a linear region and a nonlinear region in its photoelectric conversion output characteristics, and furthermore, this linear region is the only input information, and the device's It has been stated that in order to expand the dynamic range, it is necessary to extend the linear region. The dynamic range of such a conventional solid-state image sensor is about 60 to 70 dB.

[0003] Another example of the prior art is the overflow of excessive signal charges in the vertical CCD, which occurs when a part of the subject of a solid-state image sensor using the VOD blooming suppression method has an extremely high brightness. In order to suppress the blooming phenomenon, the storage capacitance of the vertical CCD is designed to be at least twice the storage capacitance of the photodiode. This is a 1/3 inch 360,000 pixel IT-
"CCD Sensor", Television Society Technical Report, Vol. 15, No. 16, pp. 31-36.

0004

[Problems to be Solved by the Invention] When attempting to expand the dynamic range of a solid-state imaging device using the conventional technology, the linear region of the photoelectric conversion output characteristics is expanded by optimizing the design of the photoelectric conversion section. In this case, the amount of expansion of the dynamic range is only about several percent to several tens of percent.

An object of the present invention is to provide a solid-state imaging device having a large dynamic range of 80 to 100 dB or more. Solid-state imaging devices having such a large dynamic range are strongly desired for still cameras, aerospace cameras, and the like.

Another object of the present invention is to improve the vertical CCD as described above.
The purpose of the present invention is to reliably prevent the blooming phenomenon caused by the overflow of excessive signal charges.

[0007]

[Means for Solving the Problems] In order to achieve the above object, the solid-state imaging device of the present invention includes a plurality of photoelectric conversion units whose photoelectric conversion output signal characteristics are in a linear region and a nonlinear region. The photoelectric conversion output signal in the nonlinear region is also used as input information together with the photoelectric conversion output signal in the linear region.

The photoelectric conversion output signal in the nonlinear region is converted to A/
A digital signal processing technique such as a D (analog/digital) converter is used to convert the signal into a linear output signal. It has coefficient storage means for holding conversion coefficients for converting the photoelectric conversion output signal in the nonlinear region into a linear output signal. The photoelectric conversion output signal in the nonlinear region is converted into a linear output signal using, for example, an exponential function. This exponential function is composed of a plurality of exponential function expressions depending on the photoelectric conversion output signal level in the nonlinear region. The plurality of photoelectric conversion sections have different photoelectric conversion characteristics for each of the plurality of groups, and the photoelectric conversion output signal in the nonlinear region is converted into a linear output signal using a different function for each of the plurality of groups. Conversion of the photoelectric conversion output signal in the nonlinear region to a linear output signal is performed according to a conversion coefficient table (lookup table). Further, the photoelectric conversion output signal in the nonlinear region is used as input information for generating a control signal within the solid-state imaging device.

On the other hand, instead of converting the photoelectric conversion output signal in the nonlinear region into a linear output signal, the photoelectric conversion output signal in the linear region is converted into a nonlinear output signal using digital signal processing technology such as an A/D converter. May be converted. In this case as well, coefficient storage means is provided for holding conversion coefficients for converting the photoelectric conversion output signal in the linear region into a nonlinear output signal. As this coefficient storage means, a mask ROM is used.
, EPROM, EEPROM, optical disk, non-volatile read-only memory such as magneto-optical disk, etc. are used. In addition,
The conversion of the photoelectric conversion output signal in the linear region to the nonlinear output signal is performed using, for example, a logarithmic function.

Further, the solid-state imaging device of the present invention is formed on a semiconductor substrate, the base of which is commonly grounded, and each emitter in an electrically floating state can store photoelectric conversion signal charges. A plurality of photoelectric conversion sections consisting of bipolar transistors, a reading means for the photoelectric conversion signal charge stored in the emitter, and a means for reading out the photoelectric conversion signal charge stored in the emitter, and an excess overflowing from the emitter that is in an electrically floating state when a high-intensity optical signal is input. In a solid-state imaging device, the solid-state imaging device includes means for applying an appropriate voltage to the collectors of the plurality of bipolar transistors in order to sweep the signal charges through the respective collectors or a common collector of the plurality of bipolar transistors. The photoelectric conversion output signals read out from the plurality of photoelectric conversion sections whose charges are being swept out are also input together with the photoelectric conversion output signals read out from the photoelectric conversion sections whose excess signal charges are not being swept out. Use as information.

[0011] A photoelectric conversion output signal read out from the photoelectric conversion section whose excess signal charge is swept out via the collector is read out from the photoelectric conversion section when it is assumed that this sweeping out is not carried out. The level of the photoelectric conversion output signal is converted using digital signal processing technology. At this time, mask ROM, EPROM, EEPRO
It has a coefficient storage means for holding conversion coefficients, such as a non-volatile read-only memory of an optical disc or a magneto-optical disc. This conversion is performed using, for example, an exponential function. This exponential function is composed of a plurality of exponential function expressions depending on the level of the photoelectric conversion output signal read from the photoelectric conversion unit from which excess signal charges are being swept out via the collector. The plurality of photoelectric conversion sections have different photoelectric conversion characteristics for each of the plurality of groups. Assuming that sweeping is not performed, the level of the photoelectric conversion output signal to be read from the photoelectric conversion unit is converted using different functions for each of the plurality of groups. Photoelectric conversion of the photoelectric conversion output signal read out from the photoelectric conversion unit whose excess signal charge is swept out via the collector, and which should be read out from the photoelectric conversion unit when it is assumed that this sweeping out is not performed. Conversion to the level of the output signal is performed according to a conversion coefficient table. A photoelectric conversion output signal read out from a plurality of photoelectric conversion units or a single photoelectric conversion unit from which excess signal charges are swept out via the collector,
Used as input information for generating control signals within the device.

0012

[Operation] In the present invention, even if the photoelectric conversion output signal characteristics exceed the linear region and enter the nonlinear region with nonlinearity, this can be used as input information, so the dynamic range of the solid-state imaging device can be significantly increased. can be improved.

Furthermore, in the present invention, the characteristics when the photoelectric conversion output signal characteristics exceed the linear region and enter the nonlinear region are used as input information, and by controlling the aperture or electronic shutter operation, etc., excessive noise in the vertical CCD is eliminated. Blooming phenomenon caused by overflow of signal charges can be reliably prevented.

[0014]

【Example】

(First Embodiment) A first embodiment of the present invention will be described below with reference to FIGS. 1 and 2. FIG. 1 is a configuration diagram of a solid-state imaging device according to this embodiment. On the semiconductor substrate, unit pixels 5 each consisting of a bipolar transistor 1, a readout gate switch 3, and a vertical CCD register 4 are arranged in an m×n matrix. The bases of the bipolar transistors 1 of each pixel are commonly grounded, and the collectors 2 are applied with a predetermined voltage. The collector 2 at this time is a common collector using the n-type semiconductor substrate itself. One end of all the vertical CCD registers 4 is connected to a horizontal CCD register 6, and one end of this horizontal CCD register 6 is further input to an output amplifier 7. The configuration up to this point is a conventional interline CCD.
The basic configuration is the same as that of a type solid-state image sensor. Output amplifier 7
The output of correlated double sampling (CDS) circuit 8, A
/D converter 9, and then an arithmetic operation unit (ALU) 10.
Enter. ALU10 is a read-only memory (RO
M: Read only memory (Read Only M
Using data sent from the memory) 11, predetermined data processing is performed according to instructions from a central processing unit (CPU) 12, and the calculation results are output to an output terminal 13. The CPU 12 also exchanges signals with the outside using the bus 14, and also instructs the operating conditions of the drive circuit 15 of the imaging section.

The operation of this embodiment will be explained below. Signal light incident on each pixel 5 is photoelectrically converted between the emitter and base of the npn bipolar transistor 1, and signal charges consisting of photoelectrons are accumulated in the electrically floating emitter. The accumulated signal charges are read out to the vertical CCD register 4 via the readout gate switch 3 at a predetermined timing, and then sequentially input to the output amplifier 7 via the horizontal CCD register 6. The output amplifier 7 outputs a signal corresponding to the amount of signal charge accumulated in the emitter of the bipolar transistor 1. Here, the above bipolar transistor 1
When extremely strong signal light is incident on the emitter, which is in an electrically floating state, signal charges generated in the emitter may overflow to adjacent pixels or the vertical CCD register 4, which may cause a phenomenon of image quality deterioration called blooming. On the other hand, it is known that this blooming can be suppressed by applying a predetermined voltage to the common collector 2 using the n-type semiconductor substrate itself and sweeping out the excess signal charge generated in the emitter to the n-type semiconductor substrate. This is called VOD (Vertical Overflow Drain).
n)) It is called blooming suppression method. However, when the VOD blooming suppression method is used as in this embodiment, it is known that a knee characteristic occurs in the signal charge accumulated in the emitter of the bipolar transistor 1. This will be explained using FIG. 2.

FIG. 2 shows an example of measuring the output signal characteristics at point a shown in FIG. 1, where (a) is linear and (b) is logarithmic, the horizontal axis represents the light receiving surface illuminance, and the vertical axis represents the output signal characteristic. It shows the output signal of the amplifier 7. Region A in the figure is the output signal characteristic before VOD blooming suppression starts working, and shows good linearity. On the other hand, region C is the output signal characteristic when VOD blooming suppression is working, and can be approximately approximated by a logarithmic function. Region B is a transition region between both regions, and corresponds to the point where VOD blooming suppression begins to work. The bending of the output signal characteristics as shown in (a) is called the knee characteristic, and this means that the potential of the base region when the excess signal charge generated at the emitter of the bipolar transistor 1 is swept out to the n-type semiconductor substrate is This phenomenon occurs when the amount of signal charge accumulated in the emitter is modulated by the value of this sweep current.

As described above, the output signal of the output amplifier 7 has a knee characteristic and consists of a linear region shown as region A in FIG. 2 and a nonlinear region shown as regions B and C having nonlinearity. Here, in the present invention, similarly to the linear region A,
Nonlinear regions B and C having nonlinearity can also be treated as signals. The output signal of the above output amplifier 7 is C
After low-frequency noise is reduced through the DS circuit 8, it is converted into a digital signal by the A/D converter 9 and inputted to the ALU 10, where the signals belonging to nonlinear regions B and C are also converted to linear signals. Ru. The ROM 11 stores conversion coefficients and functions necessary for this conversion operation in advance, and the CPU 1
2 transfers the conversion coefficient and function according to the level of the signal input to the ALU 10 from the ROM 11 to the ALU 10;
Cause the conversion operation to be performed. At this time, it is convenient to use an exponential function for converting signals belonging to the above-mentioned region C, and possibly region B as well. The input data to the ROM 11 may be created based on the knee characteristic measurement data of each solid-state imaging device, or may be created based on the knee characteristic measurement data of each solid-state imaging device, or may be created based on the knee characteristic measurement data of each solid-state imaging device. It may be created based on theoretical characteristic values or theoretical characteristics. The linear signal after the above conversion operation is output to the output terminal 13, but the CPU 12
uses the value of this output signal as an input to instruct the optimal operating conditions of the drive circuit 15 of the imaging section, such as electronic shutter operation.

As described above, since the VOD blooming suppression method is used in the pixel portion, the output signal of the output amplifier 7 has a knee characteristic and consists of a linear region and a nonlinear region. The output signal of the output amplifier 7 is converted into a digital signal by the A/D converter 9 and inputted to the ALU 10, where signals belonging to the nonlinear region are also converted to linear signals. The ROM 11 stores in advance conversion coefficients and functions necessary for this conversion operation, and the CPU 12 stores the conversion coefficients and functions necessary for this conversion operation.
The conversion coefficients and functions corresponding to the level of the signal input to the ALU 10 are transferred from the ROM 11 to the ALU 10 to perform a conversion operation.

In the above embodiment, the output signal of the output amplifier 7 is converted into a digital signal by the A/D converter 9, and then the signals belonging to the nonlinear regions B and C are converted into linear signals by the ALU 10. However, conversely, in the above ALU 10, the signal belonging to the linear region A is a nonlinear signal (exponential function signal).
It may be converted to . At this time, ALU10
The number of output bits can be compressed, which is advantageous in communication with the outside of the solid-state imaging device, recording of output data, etc. Note that it is convenient to use a logarithmic function for converting signals belonging to region A in this case.

(Second Embodiment) A second embodiment of the present invention will be described below with reference to FIG. FIG. 3 is a configuration diagram of another solid-state imaging device according to the present invention. On the semiconductor substrate, a bipolar transistor 1, a read gate switch 3,
m' unit pixels 5' each consisting of a horizontal CCD register 6 are arranged in a line. The bases of the bipolar transistors 1 of each pixel are commonly grounded, and the collectors 2 are applied with a predetermined voltage. The collector 2 at this time is a common collector using the n-type semiconductor substrate itself. One end of the horizontal CCD register 6 is input to an output amplifier 7. The configuration up to this point is the conventional 1
The basic configuration is the same as that of a dimensional CCD type solid-state image sensor. The output of the output amplifier 7 passes through the conversion function circuit 16 and outputs the conversion result to the output terminal 17. The operation of this embodiment will be explained below. This embodiment is the same as the first embodiment described above, except that the pixels are arranged one-dimensionally, to the extent that an output signal having a knee characteristic is obtained from the output amplifier 7. However, in this embodiment, the output signal (y=f(x)) of the output amplifier 7 is converted into a conversion function circuit 16 using the conversion formula y=cx/f
(x). Here, the coefficient c is an appropriate constant, and the conversion function circuit can be appropriately constructed using a diode clamp circuit, a bipolar circuit, or the like. By operating such an analog conversion function, in this embodiment, the linear characteristic of y=cx can be obtained at the output terminal 17 at a relatively low cost. Although only one row of pixels is shown in FIG. 3, by providing multiple rows of such pixels or solid-state imaging devices and configuring color filters each having different color characteristics, it is possible to create a color-capable solid-state imaging device. It is also possible to do so.

(Third Embodiment) A third embodiment of the present invention will be described below with reference to FIG. FIG. 4 is a block diagram of a third embodiment 25 of the solid-state imaging device according to the present invention, and the driving circuit 15 of the imaging section instructs the operating conditions of not only the imaging section 18 but also the optical system 22. There are four types of knee characteristics of the pixels of the imaging unit 18 for each color of the color filter, and the ROM
19 is divided into four parts, and the output of the ALU 10 does not directly become the output of the solid-state imaging device, but becomes the input of the input/output circuit 20, and this input/output circuit 20 is connected to the outside via the input/output means 21. The second embodiment is the same as the first embodiment except that it is connected to the second embodiment. The input/output circuit 20 and input/output means 21 may be a decoder/encoder for external communication, an external bus, or a communication means, or may be a VTR device and a VTR cassette tape.

The operation of this embodiment will be explained below. The operation of this embodiment is almost the same as that of the first embodiment described above, but
The drive circuit 15 of the imaging section can instruct not only the imaging section 18 but also the operating conditions of the optical system 22 such as the diaphragm, and the storage area of the conversion coefficients and functions in the ROM 19 necessary for the conversion operation in the ALU 10 is It is divided into four types according to the knee characteristics of the pixels of the imaging unit 18, and is characterized by the fact that these four types of conversion operations in the ALU 10 are sequentially performed. Due to the latter, in this embodiment, it is possible to design an optimal light-receiving region structure having four different knee characteristics for each color of the color filter. In this embodiment, the color filter has four types of colors, but if the number of storage areas for conversion coefficients and functions in the ROM 19 is changed, three types can be used.
It goes without saying that other numbers such as two types may be used.

(Fourth Embodiment) A fourth embodiment of the present invention will be described below with reference to FIG. FIG. 5 is a configuration diagram of another solid-state imaging device according to the present invention. In this example,
The output signal of the imaging section 18 is inputted to the signal output means 23 and the level detection block 24 via the CDS circuit 8, and the level detection block 24 connects the imaging section 18 and an optical system 22 such as an aperture.
A signal is sent to the drive circuit 15 of the imaging section, which controls the image pickup section.

The operation of this embodiment will be explained below. The output signal of the imaging unit 18 is sent to the signal output means 2 via the CDS circuit 8.
3 and the level detection block 24, where the level detection block 24 gives instructions for setting the driving conditions of the imaging section 18 such as the electronic shutter by the driving circuit 15 of the imaging section, and the operating conditions of the optical system 22 such as the aperture. That is, area B
By monitoring the output signal level of the imaging unit 18 at C, the amount of signal charge transferred to the vertical CCD register of the imaging unit 18 is detected, and by appropriately controlling the drive circuit 15 of the imaging unit, the vertical CCD Blooming caused by overflow of excessive signal charges in the register can be reliably prevented. The signal output means 23 may be a decoder/encoder for external communication, an external bus, communication means, a VTR device, or the like.

Although the present invention has been described above using a CCD type solid-state imaging device having a VOD structure as an embodiment of the present invention, a MOS type solid-state imaging device having nonlinear photoelectric conversion characteristics and a type in which each pixel has a signal amplification means are also applicable. Needless to say, the present invention is also applicable to solid-state imaging devices or imaging devices having an image pickup tube.

[0026]

As described above, according to the present invention, a solid-state imaging device having a dynamic range of 80 to 100 dB or more can be realized. Also, vertical CC
Blooming phenomenon caused by excessive overflow of signal charges at D can be reliably prevented.

[Brief explanation of drawings]

FIG. 1 is a configuration diagram of a first embodiment of a solid-state imaging device of the present invention.

FIG. 2 is a diagram showing output signal characteristics at point a shown in FIG. 1;

FIG. 3 is a configuration diagram of a second embodiment of the solid-state imaging device of the present invention.

FIG. 4 is a configuration diagram of a third embodiment of the solid-state imaging device of the present invention.

FIG. 5 is a configuration diagram of a fourth embodiment of the solid-state imaging device of the present invention.

[Explanation of symbols]

1... Bipolar transistor, 2... Collector, 3... Readout gate switch, 4... Vertical CCD register, 6... Horizontal CCD register, 7... Output amplifier, 8... Correlated double sampling (CDS) circuit, 9... A/D converter , 10... Arithmetic unit (ALU), 11... Read-only memory (ROM), 12... Central processing unit (CPU), 13
...output terminal, 15...imaging section drive circuit, 16...conversion function circuit, 19...ROM, 20...input/output circuit, 21...input/output means, 22...optical system, 23...signal output means, 24...level detection block .

Claims (24)

[Claims] 1. A solid-state imaging device having a plurality of photoelectric conversion units whose photoelectric conversion output signal characteristics are in a linear region and a nonlinear region, wherein the photoelectric conversion output signal in the nonlinear region is also
A solid-state imaging device characterized in that it is used as input information together with the photoelectric conversion output signal in the linear region. 2. The solid-state imaging device according to claim 1, wherein the photoelectric conversion output signal in the nonlinear region is converted into a linear output signal. 3. The solid-state imaging device according to claim 2, wherein the photoelectric conversion output signal in the nonlinear region is converted into a linear output signal using digital signal processing technology. 4. The solid-state imaging device according to claim 2, further comprising coefficient storage means for holding conversion coefficients for converting the photoelectric conversion output signal in the nonlinear region into a linear output signal. 5. The solid-state imaging device according to claim 2, wherein the photoelectric conversion output signal in the nonlinear region is converted into a linear output signal using an exponential function. 6. The solid-state imaging device according to claim 5, wherein the exponential function is composed of a plurality of exponential function equations depending on the photoelectric conversion output signal level in the nonlinear region. 7. The plurality of photoelectric conversion sections have different photoelectric conversion characteristics for each of the plurality of groups, and the photoelectric conversion output signal in the nonlinear region is a function different for each of the plurality of groups, and the photoelectric conversion output signal is converted into a linear output signal, respectively. 3. The solid-state imaging device according to claim 2, wherein the solid-state imaging device performs conversion. 8. The solid-state imaging device according to claim 2, wherein the photoelectric conversion output signal in the nonlinear region is converted into a linear output signal according to a conversion coefficient table. 9. The solid-state imaging device according to claim 1, wherein the photoelectric conversion output signal in the nonlinear region is used as input information for generating a control signal within the solid-state imaging device. 10. The solid-state imaging device according to claim 1, wherein the photoelectric conversion output signal in the linear region is converted into a nonlinear output signal. 11. The solid-state imaging device according to claim 10, wherein the photoelectric conversion output signal in the linear region is converted into a nonlinear output signal using digital signal processing technology. 12. The solid-state imaging device according to claim 11, further comprising coefficient storage means for holding conversion coefficients for converting the photoelectric conversion output signal in the linear region into a nonlinear output signal. 13. The solid-state imaging device according to claim 11, wherein the photoelectric conversion output signal in the linear region is converted into a nonlinear output signal using a logarithmic function. 14. The coefficient storage means is a mask ROM, an EP
13. The solid-state imaging device according to claim 4, wherein the solid-state imaging device is a nonvolatile read-only memory such as a ROM, an EEPROM, an optical disk, or a magneto-optical disk. 15. A plurality of photovoltaic transistors formed on a semiconductor substrate, the bases of which are commonly grounded, and each emitter in an electrically floating state can store a photovoltaic conversion signal charge. A conversion section;
A means for reading out the photoelectric conversion signal charge stored in the emitter, and a means for reading out the photoelectric conversion signal charge stored in the emitter, and a means for reading out the excess signal charge overflowing from the emitter which is in an electrically floating state when a high-intensity optical signal is input, is sent to the collector of each of the plurality of bipolar transistors. , or to flush out through a common collector,
In a solid-state imaging device having means for applying an appropriate voltage to the collector, photoelectric conversion output signals read out from a plurality of photoelectric conversion units from which excess signal charges are swept out via the collector are also used. , a solid-state imaging device characterized in that it is used as input information together with a photoelectric conversion output signal read out from a photoelectric conversion unit from which excess signal charge has not been swept out. 16. A photoelectric conversion output signal read out from the photoelectric conversion section whose excess signal charge is swept out via the collector, if it is assumed that this sweeping out is not carried out, from the photoelectric conversion section. Claim 15 characterized in that the level of the photoelectric conversion output signal to be read is converted.
The solid-state imaging device described. 17. A photoelectric conversion output signal read out from the photoelectric conversion section whose excess signal charge is swept out via the collector, assuming that this sweeping out is not carried out, 16. The solid-state imaging device according to claim 15, wherein the level of the photoelectric conversion output signal to be read is converted using digital signal processing technology. 18. A photoelectric conversion output signal read out from the photoelectric conversion section whose excess signal charge is swept out via the collector, assuming that this sweeping out is not performed, Claim 16, further comprising coefficient storage means for holding conversion coefficients when converting into the level of the photoelectric conversion output signal to be read.
The solid-state imaging device described. 19. The coefficient storage means is a mask ROM, an EP
19. The solid-state imaging device according to claim 18, wherein the solid-state imaging device is a nonvolatile read-only memory such as a ROM, an EEPROM, an optical disk, or a magneto-optical disk. 20. A photoelectric conversion output signal read out from the photoelectric conversion section whose excess signal charge is swept out via the collector, assuming that this sweeping out is not carried out, from the photoelectric conversion section. 18. The solid-state imaging device according to claim 17, wherein the level conversion of the photoelectric conversion output signal to be read is performed using an exponential function. 21. The exponential function is composed of a plurality of exponential function expressions depending on the level of the photoelectric conversion output signal read from the photoelectric conversion unit from which excess signal charges are swept out via the collector. The solid-state imaging device according to claim 20. 22. The plurality of photoelectric conversion sections have different photoelectric conversion characteristics for each of the plurality of groups, and the photoelectric conversion read out from the photoelectric conversion section from which excess signal charges are swept out via the collector. The conversion of the output signal to the level of the photoelectric conversion output signal that should be read out from the photoelectric conversion unit when this sweeping is not performed is performed using different functions for each of the plurality of groups. The solid-state imaging device according to claim 16. [Claim 23] A photoelectric conversion output signal read out from the photoelectric conversion section whose excess signal charge is swept out via the collector, assuming that this sweeping out is not carried out, from the photoelectric conversion section. 17. The solid-state imaging device according to claim 16, wherein the level conversion of the photoelectric conversion output signal to be read is performed according to a conversion coefficient table. 24. A photoelectric conversion output signal read out from a plurality of photoelectric conversion units or a single photoelectric conversion unit from which excess signal charges are swept out via the collector is used for generating a control signal in the solid-state imaging device. 16. The solid-state imaging device according to claim 15, wherein the solid-state imaging device is used as input information.