JPH05226630A - Solid-state image pick-up device - Google Patents

Abstract

PURPOSE:To realize a solid-state image pick-up device for obtaining a certain output by controlling a dark current constituent of output a first photoelectric conversion part by using the output of a dark current detection means with a photodetector which is covered with a light-screening film. CONSTITUTION:Since photodetectors 1a and 1b of rows A and B are alternately connected to a CCD 2, the output potential change is also output alternately in the order of line and an output 16 by the photodetector 1b in the row B is only a dark current constituent since an output by the photodetector 1b in the row B is covered with a light-screening film 3. On the other hand, an output 15 by the photodetector la in the row A is the sum of the dark current constituent and the light signal constituent and the output in the order of the line is converted to voltage in sequence by an FDA 7. Then, by obtaining the difference between the output signal 15 in the row A and the output signal 16 in the row B which are output alternately by an external signal processing circuit 17, an output signal only by a photo-signal constituent where the dark current constituent is eliminated can be obtained, thus achieving a solid-state image pick-up device which can suppress scattering of output.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a solid-state image pickup device,
In particular, the present invention relates to a device for reducing the dark current.

[0002]

2. Description of the Related Art FIG. 11 is a plan view of a conventional solid-state image pickup device. In the figure, 1 is a photodetector (photoelectric conversion section), 2 is a charge coupled device (hereinafter CCD), and 5 is the photodetector 1. A transfer gate for controlling the transfer of the photoelectric charges photoelectrically converted by the CCD 2 to the CCD 2, and a floating diffusion amplifier (FDA) 7 for converting the photoelectric charges into a voltage and outputting the voltage. Further, 11 and 12 are gate electrodes provided in the front and rear stages of this amplifier, and the capacitance of the FDA 7 is set by the magnitude of the clock applied to these electrodes. Reference numeral 13 denotes a reset power supply terminal, which serves to eliminate electric charges remaining in each read operation, and is applied with a voltage V _R.

Next, the operation will be described. When light is irradiated for a certain period of time, the photodetector 1 stores signal charges photoelectrically converted, Q _Sig, and charges Q _dr due to a dark current determined by temperature. The charge Q _dr due to the dark current generates one pulse (noise) when one charge crosses the junction of the photodetector 1. Therefore, the sum of the pulses due to the charge Q _dr is generated as shot noise.

Then, when the transfer gate 5 is opened, the respective charges (Q _Sig + Q _dr ) are transferred to the CCD 2, and the C
Due to the operation of CD2, the electric charges are carried to the front of the gate electrode 11. The state at this time is shown in FIG. As a result,
A signal generated by the clock φ ₁ that exceeds the potential immediately below the gate electrode 11 is transferred to the FDA 7,

[0005]

[Equation 1]

The voltage of 2 is obtained, and the potential directly under the gate 12 is changed by the clock φ _2.
It is output from 7. Here, C is the capacitance of FDA7.

Further, FIG. 10 shows T.D.I (Time Delay Int).
FIG. 2 is a plan view of a one-dimensional solid-state imaging device performing an egration) operation. According to this method, when a one-dimensional solid-state imaging device is conventionally used to observe an object moving at high speed, accumulation of signal charges in a photoelectric conversion unit The time is too short and the amount of signal charge corresponding to the observed image becomes small, resulting in S / N of the output signal.
The problem that the ratio deteriorates can be solved.

More specifically, in this method, the S / N ratio of the output signal is improved by adding the signal charges corresponding to the same observation image among the signal charges generated by the observation image moving on the photoelectric conversion unit. In the figure, 2a is a vertical charge transfer unit (hereinafter, abbreviated as vertical CCD) for vertically transferring the charges generated in the photoelectric conversion unit 1, and 2b is a CCD like the vertical CCD 2a. A horizontal charge transfer unit (hereinafter abbreviated as horizontal CCD) configured to receive the signal charges transferred by the vertical CCD 2a and transfer them in the horizontal direction. In the figure, the arrow indicates the direction in which the observation image formed on the imaging device moves. Further, A to D are regions where a part of the observed image is formed.

Now, it is assumed that a part of the observed image is formed in the area A. When a part of the observation image with 0 _1, charge corresponding to the observation image 0 ₁ The photoelectric conversion portion 1 of the area A (q _Sig) and the charge due to the dark current determined by the temperature (q _dr) are stored. And this accumulated signal charge (q _Sig + q _dr )
The transfer gate 5 is turned on while the observation image 0 ₁ moves from the area A to the area B and is read out to the vertical CCD 2a. Then, the read signal charge (q _Sig +
q _dr ) is vertically transferred in the vertical CCD 2a. The transfer speed at this time is equal to the moving speed of the observed image.

Subsequently, when the observed image 0 ₁ reaches the region B, the signal charge (q _Sig ) and the dark current (q _dr ) corresponding to the observed image 0 ₁ are accumulated in the photoelectric conversion section 1 of the region B. .. This is the signal charge (q
_Sig + q _dr ). At this time, the next observation image 0 ₂ is formed in the region A. Then, the photoelectric conversion unit 1 in the area B
The signal charge (q _Sig + q _dr ) accumulated in step S1 is transferred to the photoelectric conversion unit while the transfer gate 5 is in the ON state while the observed image 0 ₁ moves from the region B to the region C after a predetermined accumulation time. 1 is read to the vertical CCD 2a, and the vertical CCD
The signal charge (q _Sig + Δq) read out in the area A transferred to this portion of 2a is added to form a double signal charge (2q _Sig + 2q _dr ). That is, the signal charge amount corresponding to the observed image 0 ₁ is doubled. Therefore, when n photoelectric conversion units 1 are arranged in the vertical direction and this operation is repeated n times, the signal charge amount corresponding to the observed image 0 ₁ is n times (nq _Sig
+ Nq _dr ), shot noise due to dark current is √n times. Then, after the signal charges accumulated in the vertical CCD 2a and multiplied by n in this way are transferred to the horizontal CCD 2b,
Transferred to FDA7. At this time, nq _Sig = Q _Sig ,
Viewed as nq _dr = Q _dr , this state is similar to that shown in FIG.

[0011]

The conventional solid-state image pickup device is constructed as described above, and when the temperature rises and the dark current components (q _dr , Q _dr ) increase, it is output from the FDA 7 in the subsequent stage. Voltage,

[0012]

[Equation 2]

However, there is a problem in that the potential becomes larger than the potential of the gate electrode 12 shown in FIG. 12, an accurate signal charge Q _Sig cannot be obtained, and image deterioration is caused.

The present invention has been made to solve the above problems, and it is an object of the present invention to obtain a solid-state image pickup device capable of obtaining a constant output by effectively removing a dark current component which fluctuates due to heat. To aim.

[0015]

In the solid-state image pickup device according to the present invention, the output of the first photoelectric conversion unit is transferred by the first charge transfer unit, and this is converted into a voltage by the first voltage conversion unit. In the solid-state imaging device described above, a dark current detecting unit that has a photodetector covered with a light-shielding film, detects the photodetector output as a dark current, and a dark current component of the output of the first photoelectric conversion unit is provided. And a dark current control means for controlling according to the output of the dark current detection means.

[0016]

In the present invention, since the dark current detecting means output having the photodetector covered with the light shielding film is used to control the dark current component of the output of the first photoelectric conversion portion, it varies depending on the temperature. It is possible to effectively remove the dark current component that occurs.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A solid-state image pickup device according to an embodiment of the present invention will be described below with reference to the drawings. 1 and 2, in FIG.
0 and the same symbols as FIG. 11 indicate the same or corresponding parts,
Two sets of solid-state imaging device configurations as shown in FIG. 11 are provided,
Each photoelectric conversion unit (photodetector) connected to one CCD 21
1b is covered with the light-shielding film 3, and the FD in the latter stage of the CCD 21 is
A7b is connected to the gate electrode 11a at the previous stage of the other FDA 7a by a metal wiring 14, and the output of the FDA 7b is applied to the gate electrode 11a. The reset voltage V _Ra is applied to the reset power supply terminal 13a and the reset voltage V _Rb is applied to the reset power supply terminal 13b.

Next, the operation will be described. When the transfer gates 5a and 5b are opened after being irradiated with light for a certain period of time, the photocharges accumulated in the photodetectors 1a and 1b are transferred from the photodetectors 1a and 1b to the CCDs 2 and 21, respectively. At this time, the detector 1b is shielded by the light-shielding film 3, so that light does not enter, and charges due to a dark current mainly determined by the temperature are stored, and the charges based on this dark current are transferred to the CCD 21.

Then, when the charge Q _{dr of} the dark current sent from the CCD 21 that exceeds the potential barrier directly below the gate electrode 11b is transferred to the FDA 7b, the metal wiring 14 is

[0020]

[Equation 3]

The voltage of is generated. Where C is FDA7b
Is the capacity of.

Due to this voltage change, as shown in FIG. 2, the voltage of the gate electrode 11a changes, and the potential under the gate electrode 11 rises by ΔV above the potential due to the clock φ ₁ . And this potential increase ΔV
The height of the potential barrier under the gate electrode 11 due to
Dark current component Q _{dr of the} photodetector 1a carried by the CCD 2
Is set so as not to flow into the well of the FDA 7a, only the signal charge Q _Sig can be taken out.
For example, by applying the clock φ ₁ with the photodetector 1a shielded from light, the potential ΔV below the gate electrode 11a is prevented by ΔV so that signal charges due to only the dark current accumulated in the CCD 2 in the preceding stage of the gate electrode 11a do not flow into the FDA 7a. By setting the height of the barrier, even if ΔV fluctuates due to a temperature change thereafter, only the gate electrode 11a corresponding to this changes.
The lower barrier also changes, and only the signal charge component is transferred to the FDA 7a.

The remaining dark current component Q _dr is discharged by applying the reset voltage voltage V _Ra .

As described above, according to this embodiment, one CC
The photodetector 1b connected to D21 is covered with the light shielding film 3,
The charge flowing into DA7b is changed into voltage, and the other CC
Since it is added to the gate electrode 11a in the previous stage of the FDA 7a of D2, the potential of the gate electrode 11a is FDA.
It rises by the amount corresponding to the dark current flowing into 7a, and FD
Only the signal charge Q _Sig flows into A7a, and only the dark current can be effectively eliminated.

It is possible to increase the saturation limit of the FDA 7 by setting the capacitance C of the FDA 7 large, but if the capacitance C is increased, the sensitivity at the time of converting a small signal charge into a voltage is lowered, and as a result, This leads to a decrease in imaging sensitivity. However, in the present embodiment, only the dark current component due to the dark current is detected, and the dark current component is removed from the photocharge converted by the photodetector 1a by the amount corresponding thereto, so that the imaging sensitivity is not lowered. ..

Next, a second embodiment of the present invention will be described with reference to FIG. In this embodiment, the light converters 1a. 1b are arranged in a zigzag pattern, and the optical converters 1b in one row are covered with the light shielding film 3. Here, the photodetector 1b row covered with the light shielding film 3 is referred to as a B row, and the photodetector 1a row not covered with the light shielding film 3 is referred to as an A row.

Next, the operation will be described. FIG. 4 shows changes in the output voltage when the solid-state imaging device is operated.
The horizontal axis represents the passage of time, and the vertical axis represents the output voltage. Again 1
Reference numeral 5 shows a signal change by the photodetector 1a in the A row, and 16 shows a signal change by the photodetector 1b in the B row. As shown in the figure, the photodetectors 1a and 1b in the rows A and B are CCDs alternately.
Since it is connected to 2, the output potential change is alternately output line-sequentially. Therefore, the output 16 from the photodetector 1b in the B-row is only the dark current component Q _dr because it is covered with the light-shielding film 3. On the other hand, the output 15 from the photodetector 1a in the column A is the sum (Q _dr + Q) of the dark current component and the optical signal component.
_Sig ). Therefore, after the line-sequential output is sequentially converted into a voltage by the FDA 7 having a relatively large capacitance, the external signal processing circuit 17 alternately outputs the output signal 15 of the A column and the output signal 16 of the B column. Difference (Q _dr + Q
By taking _Sig− Q _dr ), it is possible to obtain an output signal based only on the optical signal component from which the dark current component has been deleted, and suppress variations in output.

Next, a third embodiment of the present invention will be described with reference to FIG. In this embodiment, a normal photodetector and a photodetector covered with a light-shielding film are alternately arranged on one side of the same CCD, and a skimming gate is provided between the non-light-shielded photodetector and the transfer gate. This is provided so that the output of the light detector shielded from light is provided to remove the dark current component of the light detector not shielded from light which is transferred to the CCD. In FIG. 5, 1b is a dummy photodetector covered with the light-shielding film 3, 6 is a skimming gate provided between the photodetector 1a and the transfer gate 5, and the output of the dummy photodetector 1b is given. It is designed to be used. Reference numeral 8 denotes a reset drain for receiving the output of the reset gate 9 and discharging the dark current remaining in the photodetectors 1a and 1b to the outside.

Next, the operation will be described. FIG. 6 is a potential diagram for explaining the operation of this embodiment.
6 (a) is the photocharge accumulation period, FIG. 6 (b) is the charge transfer period from the photodetector 1a to the CCD 2, and FIG. ) Represents the reset period of the photodetector 1 and the dummy photodetector 1 with the light shielding film 3, respectively.

First, the photocharge accumulation period shown in FIG. 6A will be described. Since a low level voltage is applied to the transfer gate 5 and the reset gate 9, these gates are off. Therefore, the optical signal charge Q _Sig and the dark current component Q _dr are accumulated in the photodetector 1a. On the other hand, only the dark current component Q _dr is accumulated in the dummy photodetector 1b. The dummy photodetector 1b communicates with the skimming gate 6, and the potential height of the skimming gate changes in conjunction with the dark current component due to the temperature change of the dummy detector 1b, and the potential of the charge of the dummy detector 1b is changed. Adjusted to match height.

Next, during the charge transfer period of FIG. 6B, a high level voltage is applied to the transfer gate 5,
The charges accumulated in the photodetector 1a are transferred to the CCD 2. At this time, the potential height of the skimming gate 6 is adjusted to match the charge potential height of the dummy photodetector 1b. , The dark current component Q _dr of the photodetector 1a is not transferred, and thus the optical signal component Q _Sig
Only transferred.

Next, during the reset period of FIG. 6C, a low level voltage is applied to the transfer gate 5 and a high level voltage is applied to the reset gate 9, so that the photodetector 1a and the dummy photodetector 1b are applied. The dark current component charge Q _dr is extracted to the reset drain 8, and the photodetector 1a and the dummy photodetector 1b are reset. As described above, only the optical signal charge Q _Sig is transferred to the CCD 2
Can be transferred to.

Next, a fourth embodiment of the present invention will be described. In this embodiment, the case where the present invention is applied to a solid-state image pickup device which performs T / D / I operation is shown. As shown in FIG. 7, the photodetector 1a and the dummy photodetector 1b covered with the light shielding film 3 are alternately arranged. Along with the arrangement, the vertical transfer CCD 2a is provided with a pair of dummy photodetectors 1b and a dark current removing unit 27 for removing a dark current component from the signal charge transferred from the photodetector 1a one before. The photodetector 1b provided with the light shielding film 3 serves as the dark current detector 26, and the dark current detector 26 and the dark current removing unit 27 constitute the dark current removing device 10. .. In addition, the arrow in the figure indicates the direction in which the observation image formed on the imaging device moves. In addition, A to B indicate regions where a part of the observed image is formed.

8 and 9 are a plan view showing a detailed structure of the dark current removing device 10 of FIG. 7 and cross-sectional views of respective portions thereof, in which 71 is a dark current detector 26.
A floating diffusion amplifier (FDA) for converting the dark current component Q _dr read from the device into a voltage, 2
Reference numerals 8 and 29 are CCD gate electrodes for controlling the transfer of signal charges in the CCD 2a, and 30 is the gate electrode 2
An n ⁺ -type region located below 8 and 29, in which a potential well is formed and in which the signal charge in the CCD 2 is transferred, 31
Is a storage gate electrode for storing the signal charges transferred to the dark current removing section 27. Reference numeral 32 denotes a skimming gate to which the output voltage of the dark current component detected by the dark current detector 26 is applied and which removes (skims) a signal charge equivalent to the output voltage of the dark current component from the signal charge, 33 is a dark current component removal gate for removing the dark current component left in the storage gate 31, 34 is an overflow drain for discharging the dark current component, and 35 is FDA.
Reference numeral 71 is a reset gate, and 37 is a metal wiring for wiring the FDA 71 and the skimming gate 32. Further, it is assumed that the reset voltage V _{R is} applied to the reset power supply terminal 36.

The operation will be described. When the signal charges including the dark current component are transferred from the photodetector 1a in the area A through the n ⁺ area 30 of the vertical transfer CCD 2a to the dark current removing device 10 by the T / D / I operation, the dark current is detected first. The transfer gate 5 of the device 26 is turned on, and the charge Q _dr due to the dark current is read out to the FDA 71. As a result, the metal wiring 37

[0036]

[Equation 4]

The voltage of (3) is generated and applied to the skimming gate 32. Here, C is the electrostatic capacitance of the FDA 71. Due to this voltage change of the skimming gate 32, the potential under the skimming gate 32 is ΔV.
Only rises. If the increase amount ΔV of this potential is set so as to prevent the dark current component Q _dr contained in the signal charges transferred from the photodetector 1a and accumulated in the accumulation gate 31, the signal charges are stored in the CCD 29 in the subsequent stage. Only the component Q _sig is transferred, so only the signal charge component Q _sig can be extracted. For example, it is necessary to set the barrier of the skimming gate 32 with respect to ΔV so that the charge composed of only the dark current component accumulated in the charge accumulation gate 31 does not flow into the CCD 29 when the photodetector 1a is shielded from light. Then, even if ΔV fluctuates due to a temperature change thereafter, the barrier below the skimming gate 32 also changes accordingly, and only the signal charge component is transferred to the CCD 29.

On the other hand, the dark current component Q _dr left under the accumulation gate 31 is discharged from the overflow drain 34 by _turning on the dark current component removal gate 33. The dark current component Q _dr of the dark current detector 26 is discharged to the reset power supply terminal 36 side by turning on the reset gate 35.

If the above operation is performed for each photodetector 1a, the dark current component generated in each photodetector 1a can be completely removed by the dark current removing device 10 in the next stage, and therefore CC
It is possible to effectively suppress the occurrence of blooming without increasing the capacitance of D2, and it is possible to suppress variations in output due to changes in element temperature.

[0040]

As described above, according to the solid-state image pickup device of the present invention, the dark current of the first photoelectric conversion unit is output by using the output of the dark current detecting means having the photodetector covered with the light shielding film. Since the components are controlled, it is possible to effectively remove the dark current component that fluctuates depending on the temperature, and it is possible to always obtain a stable video signal regardless of the temperature change.

[Brief description of drawings]

FIG. 1 is a plan view showing a solid-state imaging device according to a first embodiment of the present invention.

FIG. 2 is a potential diagram for explaining the operation of the solid-state imaging device.

FIG. 3 is a plan view showing a solid-state imaging device according to a second embodiment of the present invention.

FIG. 4 is a diagram showing changes in output voltage of the solid-state imaging device.

FIG. 5 is a plan view showing a solid-state imaging device according to a third embodiment of the present invention.

FIG. 6 is a potential diagram for explaining the operation of the solid-state imaging device.

FIG. 7 is a plan view showing a solid-state imaging device which performs T / D / I operations according to a fourth embodiment of the present invention.

FIG. 8 is a detailed configuration diagram of a dark current removing device of the solid-state imaging device.

FIG. 9 is a potential diagram for explaining the operation of the dark current removing device of the solid-state imaging device.

FIG. 10 is a plan view showing a conventional T / D / I operation type solid-state imaging device.

FIG. 11 is a plan view showing the configuration of a conventional solid-state imaging device.

FIG. 12 is a potential diagram for explaining the operation of the solid-state imaging device.

[Explanation of symbols]

 1 Photodetector 2, 21 CCD 3 Light-shielding film 4 Overflow drain 5 Transfer gate 6 Skimming gate 7 FDA 8 Reset drain 9 Reset gate 10 Dark current eliminator 11, 12 Gate electrode 13 Reset power supply terminal 14 Metal wiring 26 Dark current detector 27 Dark current removal unit

[Procedure amendment]

[Submission date] September 9, 1992

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] 0002

[Correction method] Change

[Correction content]

[0002]

2. Description of the Related Art FIG. 11 is a plan view of a conventional solid-state image pickup device. In the figure, 1 is a photodetector (photoelectric conversion section), 2 is a charge coupled device (hereinafter CCD), and 5 is the photodetector 1. A transfer gate for controlling the transfer of the photoelectric charges photoelectrically converted by the CCD 2 to the CCD 2, and a floating diffusion amplifier (FDA) 7 for converting the photoelectric charges into a voltage and outputting the voltage. Further, 11 and 12 are gate electrodes provided in the front and rear stages of this amplifier, and the maximum storage of the FDA 7 depends on the magnitude of the clock applied to these electrodes.
The charge amount is set. Reference numeral 13 denotes a reset power supply terminal, which serves to eliminate electric charges remaining in each read operation, and is applied with a voltage V _R.

[Procedure Amendment 2]

[Document name to be amended] Statement

[Name of item to be corrected] 0003

[Correction method] Change

[Correction content]

Next, the operation will be described. When light is irradiated for a certain period of time, the photodetector 1 stores signal charges photoelectrically converted, Q _Sig, and charges Q _dr due to a dark current determined by temperature. This accumulated charge is excited by temperature.
Pulsed across the junction of photodetector 1 (shot
Noise).

[Procedure 3]

[Document name to be amended] Statement

[Correction target item name] 0005

[Correction method] Change

[Correction content]

[0005]

[Equation 1]

[Procedure amendment 4]

[Document name to be amended] Statement

[Correction target item name] 0010

[Correction method] Change

[Correction content]

Subsequently, when the observed image 0 ₁ reaches the region B, the signal charge (q _Sig ) and the dark current (q _dr ) corresponding to the observed image 0 ₁ are accumulated in the photoelectric conversion section 1 of the region B. .. This is the signal charge (q
_Sig + q _dr ). At this time, the next observation image 0 ₂ is formed in the region A. Then, the photoelectric conversion unit 1 in the area B
The signal charge (q _Sig + q _dr ) accumulated in step S1 is transferred to the photoelectric conversion unit while the transfer gate 5 is in the ON state while the observed image 0 ₁ moves from the region B to the region C after a predetermined accumulation time. 1 is read to the vertical CCD 2a, and the vertical CCD
The signal charge (q _Sig + q _dr ) read out in the area A transferred to this portion of 2a is added to form a double signal charge (2q _Sig + 2q _dr ). That is, the signal charge amount corresponding to the observed image 0 ₁ is doubled. Therefore, when n photoelectric conversion units 1 are arranged in the vertical direction and this operation is repeated n times, the signal charge amount corresponding to the observed image 0 ₁ is n times (nq _Sig
+ Nq _dr), Shi Yottonoizu is the √n times. The signal charges accumulated in the vertical CCD 2a in this way and multiplied by n are transferred to the horizontal CCD 2b and then transferred to the FDA 7. At this time, nq _Sig = Q _Sig and nq _dr = Q _dr
Seen as, this state is similar to that shown in FIG.

[Procedure Amendment 5]

[Document name to be amended] Statement

[Correction target item name] 0011

[Correction method] Change

[Correction content]

[0011]

[Problems that the Invention is to provide a conventional solid-state imaging device is configured as described above, the voltage output from FDA7 the rear stage,

[Procedure correction 6]

[Document name to be amended] Statement

[Correction target item name] 0013

[Correction method] Change

[Correction content]

Is output. When the temperature fluctuates, dark current
Since the components (q _dr , Q _dr ) also change , the accurate signal charge Q
There is a problem that _Sig cannot be obtained, which causes image deterioration.

[Procedure Amendment 7]

[Document name to be amended] Statement

[Correction target item name] 0020

[Correction method] Change

[Correction content]

[0020]

[Equation 3]

[Procedure Amendment 8]

[Document name to be amended] Statement

[Name of item to be corrected] 0022

[Correction method] Change

[Correction content]

Due to this voltage change, as shown in FIG.
The voltage of the gate electrode 11a changes and the clock φ₁By
The potential under the gate electrode 11 is
Increase by ΔV. And this potential increase ΔV
The height of the potential barrier under the gate electrode 11 due to
Dark current component Q of the photodetector 1a carried by the CCD 2_dr
Is set so that it does not flow into the well of FDA7a.
If the signal charge Q_Sig Only the minutes can be taken out.
For example, clock φ with the photodetector 1a shielded from light₁To
It is applied and stored in the CCD 2 in the previous stage of the gate electrode 11a.
Signal charges due to only dark current do not flow into FDA 7a
Therefore, the potential under the gate electrode 11a is
By setting the height of the barrier, WarmDegree changeQ _dr
Even if the value fluctuates, only the portion below the gate electrode 11a
The barrier is also changing, and the signal charge is generated in the FDA 7a.
Only the minutes will be transferred.

[Procedure Amendment 9]

[Document name to be amended] Statement

[Name of item to be corrected] 0023

[Correction method] Change

[Correction content]

The dark current component Q _dr remaining thereafter is a pulse current.
Exhausted by applying pressure to 12a .

[Procedure Amendment 10]

[Document name to be amended] Statement

[Correction target item name] 0024

[Correction method] Change

[Correction content]

As described above, according to this embodiment, one CC
The photodetector 1b connected to D21 is covered with the light shielding film 3,
And convert the electric charge flowing into the DA7b the voltage, the other CC
Since it is added to the gate electrode 11a in the previous stage of the FDA 7a of D2, the potential of the gate electrode 11a is FDA.
It rises by the amount corresponding to the dark current flowing into 7a, and FD
Only the signal charge Q _Sig flows into A7a, and only the dark current can be effectively eliminated.

[Procedure Amendment 11]

[Document name to be amended] Statement

[Name of item to be corrected] 0027

[Correction method] Change

[Correction content]

Next, the operation will be described. FIG. 4 shows changes in the output voltage when the solid-state imaging device is operated.
The horizontal axis represents the passage of time, and the vertical axis represents the output voltage. Again 1
Reference numeral 5 shows a signal change by the photodetector 1a in the A row, and 16 shows a signal change by the photodetector 1b in the B row. As shown in the figure, the photodetectors 1a and 1b in the rows A and B are CCDs alternately.
Since it is connected to 2, the output potential change is alternately output line-sequentially. Therefore, the output 16 from the photodetector 1b in the B-row is only the dark current component Q _dr because it is covered with the light-shielding film 3. On the other hand, the output 15 from the photodetector 1a in the column A is the sum (Q _dr + Q) of the dark current component and the optical signal component.
_Sig ). Therefore, after the line-sequential output is sequentially converted into a voltage by the FDA 7, the external signal processing circuit 17 alternately outputs the output signal 15 of the A column and the output signal 1 of the B column.
By taking the difference (6) (Q _dr + Q _Sig −Q _dr ), it is possible to obtain an output signal based only on the optical signal component from which the dark current component has been deleted, and suppress variations in output.

[Procedure Amendment 12]

[Document name to be corrected] Drawing

[Name of item to be corrected] Figure 2

[Correction method] Change

[Correction content]

[Fig. 2]

[Procedure Amendment 13]

[Document name to be corrected] Drawing

[Correction target item name] Figure 12

[Correction method] Change

[Correction content]

[Fig. 12]

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Shinsuke Nagayoshi 4-1-1 Mizuhara, Itami City, Hyogo Prefecture Mitsubishi Electric Corporation LSI Research Center

Claims (5)

[Claims] 1. A first photoelectric conversion unit comprising a photodetector,
A solid-state imaging device comprising: a first charge transfer unit that transfers the output of the photoelectric conversion unit; and a first voltage conversion unit that converts the charges transferred by the first charge transfer unit into a voltage. A dark current detecting means for detecting the photodetector output as a dark current, and a dark current component of the output of the first photoelectric conversion unit according to the dark current detecting means output. A solid-state imaging device comprising: a dark current control unit for controlling. 2. The solid-state image pickup device according to claim 1, wherein the dark current detecting unit includes a second photoelectric conversion unit in which a photodetector having the same configuration as the first photoelectric conversion unit is covered with a light shielding film, It comprises a second charge transfer unit for transferring the output of the second photoelectric conversion unit and a second voltage conversion unit for converting the charges transferred by the second charge transfer unit into a voltage. The solid-state imaging device, wherein the dark current control means controls the gate electrode of the first voltage conversion section by the output of the second voltage conversion section. 3. The solid-state image pickup device according to claim 1, wherein the dark current detection unit is located between the photodetectors forming the first photoelectric conversion unit, and the first charge transfer unit is located between the photodetectors. Is a third photoelectric conversion unit composed of a plurality of light-shielded photodetectors, the dark current control unit being line-sequentially output from the first charge transfer unit.
A solid-state imaging device comprising: a signal processing circuit that subtracts the output of the third photoelectric conversion unit from the output of the photoelectric conversion unit. 4. The solid-state image pickup device according to claim 1, wherein the dark current detecting means is a fourth photoelectric conversion unit in which a photoelectric conversion unit having the same configuration as the first photoelectric conversion unit is covered with a light shielding film. The dark current control means is a skimming gate provided between the photodetector that constitutes the first photoelectric conversion section and the first charge transfer section, and constitutes the fourth photoelectric conversion section. The solid-state imaging device is configured to receive the output of the photodetector to control the output of the photodetector that constitutes the first photoelectric conversion unit to the first charge transfer unit. 5. The solid-state image pickup device according to claim 1, wherein the first charge transfer unit sequentially superimposes a photodetector output forming the first photoelectric conversion unit on a photodetector output of a next stage. The dark current detecting means is provided between the photodetectors constituting the first photoelectric conversion unit, and the photoelectric conversion unit having the same configuration as the first photoelectric conversion unit is covered with a light shielding film. A fifth photoelectric conversion unit, wherein the dark current control unit is arranged in the first charge transfer unit so as to be located between the photodetectors at the front stage and the rear stage that form the first photoelectric conversion unit. And a dark current component from the output of the photodetector of the preceding stage which constitutes the first photoelectric conversion unit, and controls the dark current component of the skimming gate which receives the output of the photodetector constituting the fifth photoelectric conversion unit. Solid-state imaging characterized in that it is configured to output to a photodetector of Location.