JP2008104241A - Solid state imaging apparatus, and imaging apparatus provided with the solid state imaging apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a solid state imaging apparatus capable of making an operation state in a photoelectric converting unit after reset to be a constant state irrespective of incident light amount by changing a bias voltage to be given to the photoelectric converting unit at the time of reset. <P>SOLUTION: A MOS transistor T5 is provided in which a drain is connected to a gate and a drain of a MOS transistor T2 and a direct current voltage VRS is applied to its source. At this time, image data is outputted by making a MOS transistor T4 to be on by giving a signal ϕV. Then a reset operation of a pixel is started after making a gate voltage Vg of the MOS transistor T2 to be a constant voltage value by making the MOS transistor T5 to be on after giving a signal ϕRS. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a solid-state imaging device having a photosensitive element that outputs an electrical signal corresponding to an incident light amount, and an imaging device including the solid-state imaging device.

  The solid-state imaging device is not only small, lightweight, and has low power consumption, but also has no image distortion or image sticking, and is resistant to environmental conditions such as vibration and magnetic field. In addition, since it can be manufactured through a process common to LSI (Large Scale Integrated circuit) or a similar process, it is highly reliable and suitable for mass production. For this reason, solid-state imaging devices in which pixels are arranged in a line are widely used for facsimiles and flatbed scanners, and solid-state imaging devices in which pixels are arranged in a matrix are widely used for video cameras and digital cameras. By the way, such a solid-state imaging device is roughly classified into a CCD type and a MOS type by means for reading (extracting) the photocharge generated in the photoelectric conversion element. The CCD type is designed to transfer photocharges while accumulating them in a potential well, and has a drawback that the dynamic range is narrow. On the other hand, in the MOS type, the charge accumulated in the pn junction capacitance of the photodiode is read out through the MOS transistor.

  In order to widen the dynamic range of such a MOS-type solid-state imaging device, the present applicant has developed a photosensitive means capable of generating a photocurrent according to the amount of incident light, a MOS transistor for inputting the photocurrent, and the MOS transistor. And a bias unit that biases the sub-threshold current to a state where the sub-threshold current can flow, and proposed a solid-state imaging device that logarithmically converts the photocurrent (see Patent Document 1). Although such a solid-state imaging device has a wide dynamic range, the threshold characteristics of MOS transistors provided for each pixel may differ, and the sensitivity may differ for each pixel. Therefore, it is necessary to take measures such as holding output obtained by irradiating bright light (uniform light) with uniform brightness in advance as correction data for correcting the output of each pixel at the time of imaging the subject. .

  However, it is troublesome for the operator to irradiate each pixel using an external light source, and there is a problem that exposure cannot be performed uniformly uniformly. In addition, if the imaging device is provided with a uniform light irradiation mechanism, the configuration of the imaging device is complicated. In view of this, the present applicant has proposed a solid-state imaging device that can eliminate sensitivity variations among pixels without irradiating uniform light in advance (see Patent Document 2).

  According to the solid-state imaging device thus configured, a switch is installed between the photodiode that performs the photoelectric conversion operation and the MOS transistor that operates in the subthreshold region. Disconnects the electrical connection to and outputs a signal. By using the signal output at the time of reset as correction data representing the sensitivity variation of each pixel, it is possible to cancel the sensitivity variation of each pixel. However, when operated in this way, when the switch is connected after the reset is completed, charge remains in the connection portion between the photodiode and the MOS transistor, and as a result, the imaging operation is performed with the remaining charge. As a result, an afterimage phenomenon occurs.

  Therefore, in order to suppress the occurrence of the afterimage phenomenon, the present applicant connects the MOS transistor and the photodiode and completes the reset operation, and then again passes through the MOS transistor to the connection node between the photodiode and the MOS transistor. A solid-state imaging device that resets the remaining charge has been proposed (see Patent Document 3).

  A configuration of a pixel provided in the solid-state imaging device is shown in FIG. In the pixel of FIG. 17, the pn photodiode PD forms a photosensitive part (photoelectric conversion part). The cathode of the photodiode PD is connected to the drain of the MOS transistor T1, and the source of the MOS transistor T1 is connected to the drain and gate of the MOS transistor T2 and the gate of the MOS transistor T3. The source of the MOS transistor T3 is connected to the drain of the row selection MOS transistor T4. The source of the MOS transistor T4 is connected to the output signal line 16. Each of the MOS transistors T1 to T4 is a P-channel MOS transistor.

  A DC voltage VPD is applied to the anode of the photodiode PD and the drain of the MOS transistor T3. On the other hand, the signal φVPS is input to the source of the MOS transistor T2. Then, the signal φVPS is changed with ternary voltage values VH, VM, VL (VL <VM <VH). The signal φS is input to the gate of the MOS transistor T1, and the signal φV is input to the gate of the MOS transistor T4.

  Each signal is given to the pixel having such a configuration in accordance with the timing chart shown in FIG. That is, the signal φS is set to low level to turn on the MOS transistor T1, and the voltage of the signal φVPS is set to VL to start the imaging operation. In this way, by setting the voltage of the signal φVPS to VL, the MOS transistor T2 operates in the subthreshold region from the point where the gate voltage becomes a predetermined value, so that the luminance value of the subject is linearly converted to the predetermined value. An electrical signal is output, and a logarithmically converted electrical signal is output when the luminance value of the subject exceeds a predetermined value. When the time ta1 is reached, a low-level pulse signal φV is applied to turn on the MOS transistor T4, whereby a signal at the time of imaging is output to the output signal line as image data.

  Then, after setting the pulse signal φV to the high level, at time ta2, the signal φS is set to high level to turn off the MOS transistor T1, and the imaging operation is stopped, and at time ta3, the voltage of the signal φVPS is set to VH. The reset is started by making the bias voltage applied to T2 higher than that at the time of imaging. Therefore, the gate voltage Vg of the MOS transistor T2 decreases according to the luminance of the subject until time ta2, as shown in FIG. That is, the higher the luminance of the subject, the lower the value of the gate voltage Vg. Then, since reset is started at time ta3, the change starts so as to increase the value of the gate voltage Vg.

  After that, at time ta4, a low level pulse signal φV is applied, so that a signal reflecting the threshold voltage of the MOS transistor T2 is output to the output signal line. This signal represents the sensitivity variation between the pixels, and is used as correction data for correcting the sensitivity variation. Then, at time ta5, the signal φVPS is set to VL and the signal φV is set to high level, and then at time ta6, the signal φS is set to low level to turn on the MOS transistor T1. Therefore, since the photodiode PD and the MOS transistor T2 are electrically connected at time ta6, the charge remaining in the photodiode PD causes the gate voltage Vg of the MOS transistor T2 to decrease as shown in FIG. It becomes a state where an afterimage appears.

Thereafter, at time ta7, the signal φVPS is temporarily set to VM, so that the MOS transistor T2 is temporarily turned on while the photodiode PD and the MOS transistor T2 are connected via the MOS transistor T1. By doing so, the charge causing the afterimage accumulated in the connection portion between the cathode of the photodiode PD and the gate and drain of the MOS transistor T2 is discharged, and as shown in FIG. 18B, the MOS transistor T2 is discharged. The gate voltage Vg becomes higher. At time ta8, the imaging operation is started with the signal φVPS set to VL.
Japanese Patent Laid-Open No. 3-192864 JP 2001-094878 A JP 2003-163841 A

  As described above, the gate voltage Vg of the MOS transistor T2 changes as shown in FIG. 18B by operating the pixel having the configuration shown in FIG. 17 as shown in FIG. 18A. However, at time ta3, the signal φVPS is changed. Is set to VH and the reset operation of the MOS transistor T2 is started, the gate voltage Vg of the MOS transistor T2 varies depending on the luminance value of the subject. Due to the variation in the gate voltage Vg at the start of reset (time ta3) according to the luminance value of the subject, the voltage value of the gate voltage Vg at times ta6 to ta8 also varies. For this reason, there is a variation in the voltage immediately before the start of the imaging operation (time ta8) in each pixel with different brightness values of the captured subject.

FIG. 19 shows a typical example of the relationship between the sensor surface illuminance (luminance value) X and the output Y in the solid-state imaging device including the pixel having the configuration shown in FIG. FIG. 19 is an enlarged view of a low luminance region where the output Y of the solid-state imaging device changes linearly with respect to the amount of incident light, and the sensor surface illuminance on the horizontal axis is represented by a linear scale. . In FIG. 19, the output Y of the solid-state imaging device is a value after the sensitivity variation is corrected by the correction data. In FIG. 19, the solid line indicates an ideal photoelectric conversion characteristic (photoelectric conversion characteristic having a relationship of Y = X ^1.0 ) in which the output Y is proportional to the sensor surface illuminance (luminance value) X. The broken line indicates the photoelectric conversion characteristic by the output Y that is an actual measurement value.

The actual photoelectric conversion characteristic indicated by the broken line in FIG. 19 becomes a characteristic close to the curve represented by Y = X ^0.65 , and the sensor surface illuminance (luminance value) increases in the range where the solid-state imaging device performs the linear conversion operation. As a result, the actually measured value of the output Y becomes lower than the ideal value, and it can be seen that a loss occurs in the solid-state imaging device. This is because the gate voltage Vg of the MOS transistor T2 immediately before the start of the imaging operation (time ta8) in the low luminance region where the linearly converted value is output is when the reset ends when the MOS transistor T1 is turned off (time). The cause is considered to be higher than the gate voltage Vg of the MOS transistor T2 at ta6).

  That is, when the voltage of the signal φVPS is set to VM in order to improve the afterimage, the voltage value VM is constant regardless of the luminance value and the period of the voltage value VM is constant. Depending on the value, the change when the voltage of the signal φVPS is VM becomes large, and the above-described loss is considered to occur.

  In view of such problems, the present invention provides a solid state in which the operation state of the photoelectric conversion unit after reset can be made constant regardless of the amount of incident light by changing the bias voltage applied to the photoelectric conversion unit at the time of reset. An object is to provide an imaging device.

  In order to achieve the above object, the present invention provides a photosensitive element that generates an electrical signal corresponding to the amount of incident light, and generates an electrical signal that is connected to the photosensitive element and that corresponds to the photocharge from the photosensitive element. In a solid-state imaging device having a pixel including a first transistor that performs a reset operation and an output unit that outputs an electric signal from the first transistor, the pixel supplies a DC voltage to the photosensitive element. Based on the residual charge generated in the photosensitive element when light having a luminance value higher than the maximum luminance value that can be converted as image data by the electric signal is incident on the photosensitive element from a second signal line different from the line. A reset initial voltage supply unit configured to apply a first voltage value to a connection portion between the photosensitive element and the first transistor, and when the pixel performs a reset operation, After resetting the operation state of the transistor, the photosensitive element and the first transistor are connected to reset the residual charge in the photosensitive element, and the reset initial voltage is supplied immediately before resetting the residual charge in the photosensitive element. The unit supplies the first voltage value to a connection portion between the photosensitive element and the first transistor.

  In addition, the pixel includes a switch that electrically contacts and separates the photosensitive element and the first transistor, and when the pixel performs an imaging operation, the switch is turned on and the photosensitive element and the first transistor are And when the pixel performs a reset operation, the switch is turned off to disconnect the photosensitive element from the first transistor and reset the operating state of the first transistor, and then turn on the switch. The photosensitive element and the first transistor are connected to each other, and after the first voltage is supplied to the connection portion between the photosensitive element and the first transistor by the reset initial voltage supply unit, the residual charge in the photosensitive element is It is characterized by resetting.

  A first electrode connected to the photosensitive element; a control electrode connected to the first electrode and outputting the electrical signal; and a second electrode to which a ternary voltage signal is input. And when the pixel performs an imaging operation, the voltage value of the voltage signal applied to the second electrode of the first transistor is set to at least part of the high luminance side of the luminance range that can be imaged. Has a third voltage value that operates in the subthreshold region, and when the operating state of the first transistor is reset, the voltage value of the voltage signal applied to the second electrode of the first transistor is set to be the conduction value of the first transistor. When the residual voltage in the photosensitive element is reset, the voltage value of the voltage signal applied to the second electrode of the first transistor Characterized by a fifth voltage value which is a voltage value between the third and fourth voltage values.

  The reset initial voltage supply unit includes a first electrode connected to the second signal line, a second electrode connected to a connection portion between the photosensitive element and the first transistor, and ON / OFF control. A control electrode to which a control signal is input, and when the control signal is applied to the control electrode and turned ON, the voltage value from the second signal line is set to the photosensitive element and the first transistor. The second transistor is applied to the connection portion between the first and second transistors.

  The present invention also provides a solid-state imaging device that outputs an electrical signal obtained during an imaging operation as image data and outputs an electrical signal obtained after reset as correction data, and the image data and the correction data from the solid-state imaging device. An image pickup apparatus comprising: a subtractor that outputs an image signal obtained by subtracting the image signal, wherein the solid-state image pickup apparatus is any one of the solid-state image pickup apparatuses described above.

  The present invention also provides a solid-state imaging device that outputs an electrical signal obtained during an imaging operation as image data and outputs an electrical signal obtained after reset as correction data, and the image data and the correction data from the solid-state imaging device. And a signal processing unit that performs signal processing on the image signal from the subtractor, wherein the solid-state imaging device is any one of the above solid-state imaging devices. A comparator that compares the value of the correction data output from the solid-state imaging device with a reference value; and the image signal from the subtractor is signal-processed according to a comparison result in the comparator. And a determination unit that determines whether or not to output.

In the determination unit, when the comparison result in the comparator confirms that the value of the correction data is a value in a luminance range that greatly changes with respect to the luminance value,
Instead of the image signal from the subtractor, an image signal set to a value corresponding to the maximum luminance value is signal-processed and output.

  In addition, a memory in which the correction data is stored in advance is provided, and the determination unit confirms that the value of the correction data is a value in a luminance range that greatly changes with respect to a luminance value based on a comparison result in the comparator. When this is done, the image signal obtained by subtracting the image data output from the solid-state imaging device and the correction data stored in the memory is processed instead of the image signal from the subtractor. Output.

  Further, the correction data stored in the memory is correction data when the value of the correction data becomes a value in a luminance range in which the value of the correction data is substantially constant with respect to a luminance value according to a comparison result in the comparator. And

  According to the present invention, since the bias voltage in the photoelectric conversion unit at the time of discharging the residual charge can be set according to the amount of incident light to the solid-state imaging device, the residual charge that varies depending on the amount of incident light of the solid-state imaging device. The bias voltage can be set to a value according to. Therefore, it is possible to prevent the potential state of each pixel from varying immediately after the discharge operation of the residual charge of each pixel, that is, immediately before the start of the imaging operation, according to the amount of light incident on the solid-state imaging device. Further, by performing the residual charge discharging operation, it is possible to prevent the potential state of the pixel from being displaced in the opposite direction to the direction of displacement during the imaging operation from the potential state set at the time of resetting. The loss due to the displacement of the potential state after the discharge operation can be reduced.

<First Embodiment>
A first embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram illustrating an internal configuration of the imaging apparatus according to the present embodiment. FIG. 2 is a block diagram schematically showing a partial configuration of the two-dimensional MOS solid-state imaging device provided in the imaging device of FIG.

  As shown in FIG. 1, the imaging apparatus according to the present embodiment is configured to output an image signal corresponding to the amount of incident light by imaging a subject, and image data and correction data output from the solid-state imaging apparatus 1. Are subtracted to generate an image signal from which noise has been removed, an AD converter 3 for converting the image signal from the subtractor 2 into a digital signal, and an image signal converted into a digital signal by the AD converter 3 Are provided with an image processing unit 4 that performs various image processing, and a signal control unit 5 that controls the voltage value of each signal in the solid-state imaging device 1.

  In the imaging apparatus configured as described above, the solid-state imaging apparatus 1 includes pixels G11 to Gmn and rows (lines) that are arranged in a matrix (matrix arrangement) and have a circuit configuration as shown in FIG. ) 14-1, 14-2,..., 14 -n, and a vertical scanning circuit 12 that sequentially scans, and photoelectric conversion derived to the output signal lines 16-1, 16-2,. Power is supplied to the horizontal scanning circuit 13 that sequentially reads out signals in the horizontal direction for each pixel, lines 14-1 to 14-n that send signals from the vertical scanning circuit 12 to the pixels G11 to Gmn, and the pixels G11 to Gmn. The power supply line 15 and output signal lines 16-1 to 16-m to which signals from the pixels G11 to Gmn are provided. In addition to the lines 14-1 to 14-n, the output signal lines 16-1 to 16-m, and the power supply line 15, other lines (for example, a clock line and a bias supply line) are connected to each pixel. However, these are omitted in FIG.

  A pair of P-channel MOS transistors Q1, Q2 is provided for each of the output signal lines 16-1, 16-2,. Taking the output signal line 16-1 as an example, the gate of the MOS transistor Q1 is connected to the DC voltage line 17, the drain is connected to the output signal line 16-1, and the source is connected to the line 18 of the DC voltage VPS '. ing. On the other hand, the drain of the MOS transistor Q2 is connected to the output signal line 16-1, the source is connected to the final signal line 19, and the gate is connected to the horizontal scanning circuit 13.

  As will be described later, the pixels G11 to Gmn are provided with a MOS transistor T3 that outputs a signal based on the photocharge generated in these pixels. The connection relationship between the MOS transistor T3 and the MOS transistor Q1 is as shown in FIG. Here, the relationship between the DC voltage VPS ′ connected to the source of the MOS transistor Q1 and the DC voltage VPD ′ connected to the drain of the MOS transistor T3 is VPD ′ <VPS ′, and the DC voltage VPD ′ is, for example, the ground Voltage (ground). In this circuit configuration, a signal is input to the gate of the upper MOS transistor T3, and a DC voltage DC is constantly applied to the gate of the lower MOS transistor Q1. Therefore, the lower MOS transistor Q1 is equivalent to a resistor or a constant current source, and the circuit of FIG. 3A is a source follower type amplifier circuit. In this case, it may be considered that the current amplified from the MOS transistor T3 is a current.

  The MOS transistor Q2 is controlled by the horizontal scanning circuit 13 and operates as a switch element. As will be described later, a switching MOS transistor T4 is also provided in the pixel in the solid-state imaging device of each embodiment. Including the MOS transistor T4, the circuit of FIG. 3A is exactly as shown in FIG. 3B. That is, the MOS transistor T4 is inserted between the MOS transistor Q1 and the MOS transistor T3. Here, the MOS transistor T4 is for selecting a row, and the MOS transistor Q2 is for selecting a column.

  With the configuration shown in FIG. 3, the signal can be amplified and output. Therefore, when the pixel naturally converts the photocurrent generated from the photosensitive element to expand the dynamic range, the output signal is small as it is, but is amplified to a sufficiently large signal by this amplifier circuit. Therefore, the subsequent signal processing circuit (not shown) can be easily processed. Further, the output signal lines 16-1, 16-2,... Connected to a plurality of pixels arranged in the column direction without providing the MOS transistor Q1 constituting the load resistance portion of the amplifier circuit in the pixel. By providing every 16-m, the number of load resistors or constant current sources can be reduced, and the area occupied by the amplifier circuit on the semiconductor chip can be reduced.

  The configuration of each of the pixels G11 to Gmn provided in the solid-state imaging device 1 will be described with reference to the circuit diagram of FIG. In the pixel having the configuration shown in FIG. 4, elements or portions that are the same as those of the pixel having the configuration shown in FIG. 17 are denoted by the same reference numerals, and detailed description thereof is omitted. The pixel shown in FIG. 4 has a configuration in which a MOS transistor T5 whose drain is connected to a connection node between the drain and gate of the MOS transistor T2 is added to the configuration shown in FIG. This MOS transistor T5 is supplied with a signal φRS at its gate and a DC voltage VRS at its source.

  4 will be described with reference to the timing chart of FIG. FIG. 5A is a timing chart showing the transition of the state of each signal applied to the pixel, and FIG. 5B is a timing chart showing the transition of the gate voltage Vg of the MOS transistor T2. In the pixel shown in FIG. 4, first, the signal φS is set to low level to turn on the MOS transistor T1, the signal φRS is set to high level, the MOS transistor T5 is turned off, and the signal φVPS is set to VL. Perform the action. At this time, when the gate and drain of the MOS transistor T2 and the anode of the photodiode PD are electrically connected, light is incident on the photodiode PD, and a photocurrent corresponding to the amount of incident light is generated.

  When the luminance of the subject is low, the MOS transistor T2 is in a cut-off state, so that photocharge is accumulated at the gate of the MOS transistor T2, and linearly proportional to the amount of incident light at the gates of the MOS transistors T2 and T3. Appears. Also, when the luminance of the subject is high and the voltage corresponding to the amount of photocharge accumulated at the gate of the MOS transistor T2 is low, the MOS transistor T2 operates in the subthreshold region, so that the logarithm of the incident light quantity is natural logarithmically. A proportional voltage appears at the gate of the MOS transistor T2. Therefore, the gate voltage Vg of the MOS transistor T2 changes so as to decrease according to the amount of incident light as shown in FIG.

  After that, at time t1, a low level pulse signal φV is applied to the gate of the MOS transistor T4, whereby the MOS transistor T4 is turned on, and the drain current amplified by the gate voltage of the MOS transistor T3 passes through the MOS transistors T3 and T4. An output current flows through the output signal line 16 (corresponding to the output signal lines 16-1 to 16-m in FIG. 2). The output current output to the output signal line 16 is a value that is linearly or naturally logarithmically proportional to the amount of incident light. At this time, the resistance of the MOS transistor T3 and the MOS transistor Q1 (FIG. 2) and the drain voltage of the MOS transistor Q1 determined by the current flowing through them appear on the output signal line 16 as a signal, and image data is output.

  When the image data is output in this way, after the signal φV is set to the high level, at time t2, the signal φRS is set to the low level and the MOS transistor T5 is turned on. Therefore, the DC voltage VRS applied to the source of the MOS transistor T5 is applied to the gate and drain connection node of the MOS transistor T2 through the MOS transistor T5. As shown in FIG. 5B, the gate voltage Vg of the MOS transistor T2 can be forcibly set to the DC voltage VRS.

  In this way, all the pixels G11 to Gmn can turn on the MOS transistor T5 after the imaging operation, whereby the gate voltage Vg of the MOS transistor T2 in the pixel can be set to an equal voltage value. The voltage value of the DC voltage VRS applied to the source of the MOS transistor T5 is lower than the gate voltage Vg appearing at the gate of the MOS transistor T2 after imaging (voltage value in the bright state). It is said.

  At time t3, when the signal φRS is set to high level and the MOS transistor T5 is turned off, the signal φS is set to high level to turn off the MOS transistor T1, and the anode of the photodiode PD and the drain of the MOS transistor T2 The electrical connection is disconnected and the reset operation is started. At this time, positive charges flow from the source side of the MOS transistor T2, and the negative charges accumulated in the gate and drain of the MOS transistor T2 and the gate of the MOS transistor T3 are recombined. Therefore, the gate voltage Vg of the MOS transistor T2 gradually increases from the voltage value VRS as shown in FIG. 5B.

  Thereafter, at time t4, the signal φVPS is set to VH to increase the source voltage of the MOS transistor T2. Thus, by setting the signal φVPS to VH, the amount of positive charge flowing from the source side of the MOS transistor T1 is increased, and the negative charge accumulated at the gate and drain of the MOS transistor T2 and the gate of the MOS transistor T3 is increased. Charges are quickly recombined. Therefore, at time t4, the rate of change of the gate voltage Vg of the MOS transistor T2 increases, and the voltage value of the gate voltage Vg of the MOS transistor T2 further increases as shown in FIG. 5B.

  When the reset operation is performed in this way, at time t5, the low level pulse signal φV is applied to turn on the MOS transistor T4. Therefore, the drain current amplified by the reset gate voltage of the MOS transistor T3 is output as an output current to the output signal line 16 through the MOS transistors T3 and T4. The drain voltage of the MOS transistor Q1 determined by the output current output to the output signal line 16 appears on the output signal line 16 as a signal. This signal reflects the threshold voltage of the MOS transistor T2, and by obtaining this signal for each pixel, it is possible to detect the sensitivity variation between the pixels, and it is output as correction data for correcting the sensitivity variation.

  After that, at time t6, the voltage value of the signal φVPS is set to VL and the signal φV is set to high level, and then at time t7, the signal φS is set to low level. In this way, by turning on the MOS transistor T1, the anode of the photodiode PD and the drain and gate of the MOS transistor T2 are connected. Therefore, at this time, as shown in FIG. 5B, due to the charge remaining in the photodiode PD, the gate voltage Vg of the MOS transistor T2 is lowered, and an afterimage appears.

  At time t8, by setting the voltage value of the signal φVPS to VM, the MOS transistor T2 is temporarily turned on and accumulated between the photodiode PD and the anode of the photodiode PD and the drain of the MOS transistor T2. The remaining charge is recombined. Therefore, as shown in FIG. 5B, the gate voltage Vg of the MOS transistor T2 increases. At time t9, the next image pickup operation is started with the signal φVPS set to VL. The voltage values of the signals φS, φV, φRS, and φVPS given at the timing shown in FIG. 5A are changed by the signal control unit 5.

  As described above, when the pixels G11 to Gmn perform the imaging operation, the image data and the correction data are output from the pixels G11 to Gmn. Note that when the image data and the correction data output from the pixels G11 to Gmn are output from the solid-state imaging device 1, the values are inverted. That is, the output value output from the solid-state imaging device 1 increases as the luminance increases. At this time, the image data and the correction data output from the solid-state imaging device 1 are respectively supplied to the non-inverting input terminal and the inverting input terminal of the subtracter 2.

  Then, the subtracter 2 subtracts the correction data given from the solid-state imaging device 1 from the image data given from the solid-state imaging device 1, and outputs the image data in which the pixel variation is reduced by the correction data as an image signal. Is done. At this time, the subtracter 2 performs a subtraction process between the image data and the correction data in the same pixel. When the image signal output from the subtracter 2 is supplied to the AD conversion unit 3 and converted into a digital signal, the image signal converted into the digital signal is supplied to the image processing unit 4 for offset voltage processing, white Various image processes such as a balance process, a color balance process, a γ correction process, an edge enhancement process, and a gradation process are performed.

  As described above, in this embodiment, after the video data is output, the gate voltage Vg of the MOS transistor T2 of each of the pixels G11 to Gmn is first set to the same voltage value, and then the reset operation is started. Therefore, the variation in the gate voltage Vg of the MOS transistor T2 that has occurred after the video data output (time t1) is eliminated at the start of reset (time t3). Therefore, the reset starts from the same value of the gate voltage Vg of the MOS transistor T2. Therefore, the gate voltage Vg of the MOS transistor T2 when the afterimage removal is performed after the reset is completed (time t7 to t9) regardless of the value of the video data. The voltage value can be substantially constant. The gate voltage Vg of the MOS transistor T2 at the start of imaging can be made constant.

<Second Embodiment>
A second embodiment of the present invention will be described with reference to the drawings. FIG. 6 is a circuit diagram illustrating an internal configuration of a pixel provided in the solid-state imaging device of the imaging device according to the present embodiment. In the pixel having the configuration shown in FIG. 6, the same elements or portions as those of the pixel having the configuration shown in FIG. In addition, the configurations of the imaging apparatus and the solid-state imaging apparatus of the present embodiment are configured as shown in FIGS. 1 and 2, as in the first embodiment.

  As shown in FIG. 6, the pixel provided in the solid-state imaging device 1 of the imaging device according to the present embodiment is different from the pixel shown in FIG. 4 in that a signal φVRS switched by a binary voltage value is applied to the source of the MOS transistor T5. It is done. The signal φVRS is switched between a voltage value VRS1 that is the same as the DC voltage VRS in the first embodiment and a voltage value VRS2 that is higher than the voltage value VRS1. Other parts are the same as those shown in FIG.

  The operation of the pixel configured as shown in FIG. 6 will be described with reference to the timing chart of FIG. FIG. 7A is a timing chart showing the transition of the state of each signal applied to the pixel, and FIG. 7B is a timing chart showing the transition of the gate voltage VG of the MOS transistor T2. As in the first embodiment, the imaging operation is performed in a state where the signals φS and φRS are set to the low level and the high level, respectively, and the signal φVPS is set to VL.

  When the signal φV is set to the high level after the signal φV is output at the low level at time t1 and the signal φV is set to the high level, the low-level pulse signal φRS is applied at time t2 to turn on the MOS transistor T5. At this time, the voltage value of the signal φVRS applied to the source of the MOS transistor T5 is set to VRS1, and the gate voltage Vg of the MOS transistor T2 is forcibly set to the DC voltage VRS1 as shown in FIG. 7B. That is, the voltage value (voltage value in the bright state) is set so that the gate voltage Vg of the MOS transistor T2 is lower than the gate voltage Vg appearing at the gate of the MOS transistor T2 after imaging.

  Thereafter, the signals φRS and φS are set to the high level at time t3, and then the voltage value of the signal φVPS is set to VH at time t4, thereby increasing the gate voltage Vg of the MOS transistor T2 as shown in FIG. 7B. Thus, at time t5, the signal φV is set to the low level and correction data is output. Then, at time t6, the voltage value of the signal φVPS is set to VL and the signal φV is set to high level, and then at time t7, the signal φS is set to low level. At this time, the anode of the photodiode PD and the drain and gate of the MOS transistor T2 are connected, and as shown in FIG. 7B, the gate voltage Vg of the MOS transistor T2 decreases and an afterimage appears.

  After connecting the anode of the photodiode PD and the drain and gate of the MOS transistor T2 in this way, the signal φRS is set to low level and the voltage value of the signal φVRS is set to VRS2 at time t7a. Therefore, as shown in FIG. 7B, the gate voltage Vg of the MOS transistor T2 is forcibly set to the DC voltage VRS2. That is, the gate voltage Vg of the MOS transistor T2 is set to a voltage value (voltage value due to the afterimage in the bright state) that is lower than the gate voltage Vg of the MOS transistor T2 in the state in which the afterimage appears.

  At time t8, the voltage value of the signal φVPS is set to VM, and the residual charges accumulated in the photodiode PD and the drain of the MOS transistor T2 are recombined. Increase the gate voltage Vg. At time t9, the next image pickup operation is started with the signal φVPS set to VL. The voltage values of the signals φS, φV, φRS, φVPS, and φVRS given at the timing shown in FIG.

  As described above, in this embodiment, after the video data is output, the gate voltage Vg of the MOS transistor T2 of each of the pixels G11 to Gmn is first set to the same voltage value, and then the reset operation is started. Therefore, the variation in the gate voltage Vg of the MOS transistor T2 that has occurred after the video data output (time t2) is eliminated when the correction data is output (time t5). Therefore, the gate voltage Vg of the MOS transistor T2 when the correction data is output can be made constant regardless of the value of the video data.

  Further, when the voltage due to the afterimage appears as the gate voltage Vg of the MOS transistor T2 after the reset is completed (time t7), after the gate voltage Vg of the MOS transistor T2 of each of the pixels G11 to Gmn is set to the same voltage value (time t7a) Afterimage reduction operation is performed (time t8). Therefore, the variation in the gate voltage Vg of the MOS transistor T2 due to the afterimage value that has occurred after the end of reset (time t7) is eliminated at the start of the imaging operation (time t9). Therefore, the gate voltage Vg of the MOS transistor T2 at the start of imaging can be made constant regardless of the amount of charge accumulated in the anode of the photodiode PD and the drain and gate of the MOS transistor T2.

  In the first and second embodiments, the drain of the MOS transistor T5 is connected to the connection node between the source of the MOS transistor T1 and the drain of the MOS transistor T2. However, as shown in FIG. The drain of T5 may be connected to the connection node between the source of the MOS transistor T1 and the drain of the MOS transistor T2. FIG. 8 is based on the configuration of the pixels (FIG. 4) provided in the imaging apparatus according to the first embodiment.

<Third Embodiment>
A third embodiment of the present invention will be described with reference to the drawings. FIG. 9 is a block diagram illustrating a configuration of the imaging apparatus according to the present embodiment. FIG. 10 is a circuit diagram illustrating a configuration of each pixel provided in the solid-state imaging device of the imaging device of the present embodiment. In the configuration shown in FIGS. 9 and 10, the same components as those in FIGS. 1 and 4 are denoted by the same reference numerals, and detailed description thereof is omitted.

  As shown in FIG. 9, the imaging apparatus of the present embodiment has a configuration shown in FIG. 1. The correction data from the solid-state imaging apparatus 1 is input to the non-inverting input terminal and the predetermined threshold Vref is input to the inverting input terminal. And a comparator 6 for comparison is added. At this time, the comparison result obtained by comparing the correction data from the solid-state imaging device 1 with the threshold value Vref is given to the image processing unit 4 in the comparator 6, and the subtraction processing in the subtractor 2 is performed normally. It is confirmed whether or not

  In the imaging device that operates as described above, the configuration of each of the pixels G11 to Gmn in the solid-state imaging device 1 is as shown in FIG. That is, as shown in FIG. 10, the pixel of this embodiment has a configuration in which the MOS transistor T1 is removed from the configuration in FIG. 4, and the drain and gate of the MOS transistor T2 are connected to the cathode of the photodiode PD. It becomes. The drain of the MOS transistor T5 is also connected to the cathode of the photodiode PD. The operation of the pixel configured as shown in FIG. 10 will be described with reference to the timing chart of FIG. FIG. 11A is a timing chart showing the transition of the state of each signal applied to the pixel, and FIG. 11B is a timing chart showing the transition of the gate voltage VG of the MOS transistor T2.

  The pixel having the configuration shown in FIG. 10 first performs an imaging operation with the signal φRS at a high level and the signal φVPS at VL. At this time, as shown in FIG. 11B, the gate voltage Vg of the MOS transistor T2 becomes low and changes to a voltage corresponding to the amount of light incident on the photodiode. When the signal φV is set to the high level after the signal φV is output at the low level at time t1 and the signal φV is set to the high level, the low-level pulse signal φRS is applied at time t2 to turn on the MOS transistor T5. Therefore, as shown in FIG. 11B, the gate voltage Vg of the MOS transistor T2 is forcibly set to a value lower than the voltage after imaging as the DC voltage VRS.

  Thereafter, after the signal φRS is set to the high level at time t3, the voltage value of the signal φVPS is set to VH at time t4 so that the gate voltage Vg of the MOS transistor T2 becomes higher as shown in FIG. 11B. Reset to. At time t5, the signal φV is set to low level and correction data is output. At time t6, the voltage value of the time signal φVPS is set to VL and the signal φV is set to high level. In this way, after outputting the correction data, the next imaging operation is started.

  Thus, unlike the first and second embodiments, when the pixels G11 to Gmn in the solid-state imaging device 1 operate, when the gate voltage Vg of the MOS transistor T2 is reset, the photodiode PD and the MOS transistor T2 It remains connected. Therefore, when the light incident on the photodiode PD is light from a high-luminance subject, the charge generated in the photodiode PD flows into the MOS transistor T2 and affects the gate voltage Vg of the reset MOS transistor. .

  That is, when light from a high-luminance subject is incident on the photodiode PD, correction data is output without resetting the gate voltage Vg of the MOS transistor T2 to a sufficiently high voltage. Therefore, the value of the output correction data becomes higher than the value of the image data, and a black and white reversal phenomenon occurs. FIG. 12 shows the relationship between the image data and the correction data values with respect to the luminance value of the subject. First, as shown in FIG. 12, the output value of the image data increases as the luminance value increases, because the gate voltage Vg of the MOS transistor T2 decreases as shown in FIG. Note that the output values of the image data and the correction data output from the solid-state imaging device 1 are inverted with respect to the gate voltage Vg of the MOS transistor T2. That is, as the amount of incident light increases, the output voltage of the solid-state imaging device 1 increases while the gate voltage Vg of the MOS transistor T2 decreases.

  On the other hand, the output value of the correction data is such that, for incident light having a luminance value Lth or less, the gate voltage Vg of the MOS transistor T2 is constant at the DC voltage value VRS at the start of resetting, and the photo at reset Since the amount of charge generated in the diode PD is small, the gate voltage Vg of the MOS transistor T2 after the reset ends falls within a constant voltage value. Therefore, as the luminance value of incident light increases, the output value of correction data increases and becomes constant at a value lower than the threshold value Vref.

  However, when the luminance value of incident light becomes higher than Lth, the amount of charge generated in the photodiode PD at the time of reset increases, and the influence on the gate voltage Vg of the MOS transistor T2 increases. For this reason, the rate of change of the gate voltage Vg of the MOS transistor T2 becomes small, and the gate voltage Vg of the MOS transistor T2 after the reset ends becomes low. Therefore, when the luminance value of incident light is higher than Lth, the output value of the correction data monotonously increases and becomes higher than the threshold value Vref as the luminance value increases. When the luminance value of the incident light becomes extremely high, the output value of the correction data exceeds the output value of the image data.

  As described above, when the luminance value of the incident light becomes higher than the luminance value Lth, the output value of the correction data increases rapidly with respect to the luminance value. Therefore, when the subtraction process of the correction data and the image data output from the solid-state imaging device 1 is performed in the subtracter 2, if the luminance value of the incident light increases, the subtracted image signal with respect to the luminance value. Since the value of becomes smaller, a black-and-white reversal phenomenon occurs in which a bright part is actually reproduced as a dark part.

  On the other hand, in the present embodiment, as shown in FIG. 9, by providing the comparator 6, the correction data output from the solid-state imaging device 1 is compared with the threshold value Vref. Then, when the value of the correction data output from the solid-state imaging device 1 is smaller than the threshold value Vref, it is reset to a constant value as shown in FIG. For this reason, when a low level signal is output from the comparator 6, the luminance value of the subject is in the luminance range where there is no black-and-white reversal phenomenon in the image processing unit 4, and the subtractor 2 performs normal subtraction processing. That is confirmed. Therefore, in the image processing unit 4, the image signal obtained by being subtracted by the subtractor 2 from the comparator 6 and then converted into a digital signal by the AD conversion unit 3 is processed.

  Further, when the value of the correction data output from the solid-state imaging device 1 is larger than the threshold value Vref, the state is reset to a value that monotonously increases with respect to the luminance value as shown in FIG. Therefore, when a high level signal is output from the comparator 6, the image processing unit 4 confirms that the luminance value of the subject is in a luminance range that causes a black and white reversal phenomenon, and the subtractor 2 performs normal subtraction processing. It is confirmed that this has not been done. Therefore, the image processing unit 4 reads and processes an image signal corresponding to the maximum luminance value in the dynamic range that can be photographed.

  As described above, in this embodiment, the pixels G11 to Gmn have a configuration in which the MOS transistor T1 that functions as a switch for electrically connecting and separating the photodiode PD and the MOS transistor T2 is deleted, and the circuit scale in each pixel is reduced. can do. Furthermore, since it is not necessary to perform an afterimage reduction operation, output loss as shown in FIG. 19 caused by this afterimage reduction operation can be suppressed. In addition, by confirming the portion where the output value of the correction data changes monotonously with respect to the luminance value, the signal corresponding to the maximum luminance value is read and processed by the image processing unit 4, so that the photodiode PD and the MOS transistor are reset. It is possible to prevent the black and white inversion phenomenon that occurs because T2 is connected.

<Fourth Embodiment>
A fourth embodiment of the present invention will be described with reference to the drawings. FIG. 13 is a block diagram illustrating a configuration of the imaging apparatus according to the present embodiment. In the imaging apparatus shown in FIG. 13, the same components as those in the imaging apparatus of FIG. 9 are denoted by the same reference numerals, and detailed description thereof is omitted.

  As shown in FIG. 13, the imaging apparatus according to the present embodiment has a buffer 7 to which image data from the solid-state imaging apparatus 1 is input and a subtracter 2 based on the comparison result from the comparator 6 in the configuration of FIG. 9. A determination unit 8 that determines whether or not the subtraction process is normally performed, a frame memory 9 that stores correction data of each of the pixels G11 to Gmn of the solid-state imaging device 1, and a correction from the solid-state imaging device 1 An AD converter 3 a that converts data into a digital signal and outputs it to the frame memory 9, a switch SW 1 that electrically connects and disconnects the output side of the subtractor 2 and the input side of the AD converter 3, A switch SW2 that electrically connects and disconnects the output side and the input side of the AD conversion unit 3 is added.

  In the buffer 7, image data from the solid-state imaging device 1 is input to the non-inverting input terminal, and the inverting input terminal is connected to the output terminal. Further, a control signal based on the determination result by the determination unit 9 is given to the AD conversion unit 3a, the image processing unit 4, and the switches SW1 and SW2. At this time, the configuration of the pixels G11 to Gmn configured in the solid-state imaging device 1 is the configuration as shown in FIG. 10 similar to that of the third embodiment, and when the incident light to the pixel has high brightness, A reversal phenomenon occurs.

  In the imaging apparatus configured as described above, the value of the correction data output from the solid-state imaging apparatus 1 is compared with the threshold value Vref in the comparator 6 as in the third embodiment. At this time, when the luminance value of the subject is equal to or lower than the luminance value Lth at which the correction data starts monotonous change, the value of the correction data input to the comparator 6 is smaller than the threshold value Vref, and a low level signal is output. Is done. When a low level signal is output from the comparator 6, the determination unit 8 confirms that the luminance value of the subject is in a luminance range where there is no black-and-white reversal phenomenon, and that the subtractor 2 is performing the subtraction process normally. Is done.

  Then, a control signal is given from the determination unit 8 to the switches SW1 and SW2, so that the switch SW1 is turned on and the switch SW2 is turned off. When the image signal from which the noise component due to the sensitivity variation is removed by the subtractor 2 is supplied to the image processing unit 4 through the switch SW1, various types of image processing are performed. At this time, the control signal from the determination unit 8 is also supplied to the AD conversion unit 3a and the AD conversion unit 3a operates, whereby the correction data from the solid-state imaging device 1 is converted into a digital signal, and the frame memory 9 is stored.

  Further, when the luminance value of the subject is higher than the luminance value Lth at which the correction data starts monotonous change, the correction data value input to the comparator 6 is larger than the threshold value Vref and becomes a high level signal. Is output. When a high level signal is output from the comparator 6, the determination unit 8 confirms that the luminance value of the subject is in a luminance range that causes a black and white reversal phenomenon, and that the subtracter 2 has not been normally subtracted. Is done.

  Then, a control signal is given from the determination unit 8 to the switches SW1 and SW2, so that the switch SW1 is turned off and the switch SW2 is turned on. Through this switch SW2, an image signal in a state where noise components due to sensitivity variations from the buffer 7 are superimposed is given to the image processing unit 4. That is, the image data output from the solid-state imaging device 1 is output from the buffer 7 as an image signal, and is provided to the image processing unit 4 via the switch SW2 and the AD conversion unit 3.

  As described above, when the image data of the pixels G11 to Gmn based on the image signal supplied from the buffer 7 is supplied to the image processing unit 4, the correction data stored in the frame memory 9 is read out by the image processing unit 4. Thus, for each pixel, the correction data is subtracted from the image data, thereby generating an image signal from which a noise component due to pixel variation is removed. Various image processes are performed on the image signal from which the noise component due to pixel variation is removed. At this time, since the control signal from the determination unit 8 is also given to the AD conversion unit 3a and the operation of the AD conversion unit 3a is prohibited, the correction data stored in the frame memory 9 is not updated.

  As described above, in the present embodiment, even in a high luminance range where the black and white inversion phenomenon occurs, the image signal is converted into a digital signal by the AD conversion unit 3 via the buffer 7 and then applied to the image processing unit 4. Therefore, unlike the third embodiment, gradation change can be expressed even in such a high luminance range, and the contrast at high luminance can be improved.

  In the fourth embodiment, the digital signal based on the correction data output from the solid-state imaging device 1 is stored in the frame memory 9 and updated. For example, the operation state of the solid-state imaging device 1 is switched. The correction data stored in the frame memory 9 may be updated at a predetermined timing. Further, correction data confirmed in advance in a luminance range equal to or lower than the luminance value Lth for each pixel may be stored in the frame memory 9 and may not be updated.

  Further, in the third and fourth embodiments, the threshold value Vref is set to the value of the portion where the output value of the correction data with respect to the luminance value in FIG. What is necessary is just to confirm whether it exists in the brightness | luminance range to be performed. In the third and fourth embodiments, in the comparator 6, the threshold value Vref may be input to the inverting input terminal and the correction data may be input to the non-inverting input terminal.

  In the first to fourth embodiments, the image data and the correction data output from the pixels G11 to Gmn are inverted and output from the solid-state imaging device 1. However, the solid-state imaging device 1 is not inverted. May be output from. At this time, the correction data may be input to the inverting input terminal of the subtracter 2 and the image data may be input to the non-inverting input terminal, and may be inverted by the subtractor 2.

  In addition, the pixel configuration in each of the first to fourth embodiments is a circuit configuration as shown in FIGS. 4, 6, and 10, but is not limited to such a circuit configuration. A circuit may be added, or a structure having a simultaneous integration function may be used. That is, as shown in FIG. 14, each pixel in the imaging device of the first embodiment has the configuration of FIG. 4 with the MOS transistor T6 having the gate connected to the gate and drain of the MOS transistor T2, and the MOS transistor T6. The capacitor C1 having one end connected to the connection node between the source and the gate of the MOS transistor T3 and the other end applied with the DC voltage VPS, and the voltage at the connection node between the source of the MOS transistor T6 and one end of the capacitor C1 are reset. A configuration in which an integration circuit is added may be adopted by adding the MOS transistor T7 to be added.

  Further, as shown in FIG. 15, each pixel in the image pickup apparatus of the first embodiment has the configuration of FIG. 4 with the MOS transistor T8 having the drain connected to the gate and drain of the MOS transistor T2, and the MOS transistor T8. The capacitor C2 having one end connected to the connection node between the source and the gate of the MOS transistor T3 and the other end applied with the DC voltage VPD, and the voltage at the connection node between the source of the MOS transistor T8 and one end of the capacitor C2 are reset. By adding the MOS transistor T9, the MOS transistor T8 may be configured to have a simultaneous integration function in which the photoelectric conversion unit and the output unit are electrically connected to and separated from each other.

  Further, as shown in FIG. 16, each pixel in the imaging device of the first embodiment connects the drain of the MOS transistor T8 to the connection node between the source of the MOS transistor T6 and one end of the capacitor C1, and FIG. By combining the configuration in FIG. 15, an integration circuit may be added to the photoelectric conversion unit and a simultaneous integration function may be provided. Furthermore, the configuration of each pixel in the imaging device of the first embodiment has been described as an example, and the configuration including either the integration circuit or the simultaneous integration function has been described. However, in the imaging device of the second to fourth embodiments, Similarly, each of the pixels can be configured to have either an integration circuit or a simultaneous integration function by adding MOS transistors T6 to T9 and capacitors C1 and C2.

These are block diagrams which show the internal structure of the imaging device of 1st Embodiment. These are block diagrams which show schematic structure of a solid-state imaging device. FIG. 3 is a circuit diagram showing a partial configuration of the solid-state imaging device of FIG. 2. These are circuit diagrams which show the structure of the pixel in the solid-state imaging device with which the imaging device of 1st Embodiment was equipped. These are timing charts showing the operation of the pixel of FIG. These are circuit diagrams which show the structure of the pixel in the solid-state imaging device with which the imaging device of 2nd Embodiment was equipped. These are timing charts showing the operation of the pixel of FIG. These are the circuit diagrams which show the other structure of the pixel in the solid-state imaging device with which the imaging device of 1st Embodiment was equipped. These are block diagrams which show the internal structure of the imaging device of 3rd Embodiment. These are the circuit diagrams which show the structure of the pixel in the solid-state imaging device with which the imaging device of 3rd and 4th embodiment was equipped. FIG. 11 is a timing chart showing the operation of the pixel in FIG. 10. FIG. 11 is a graph showing a relationship between image data and correction data output from a solid-state imaging device including the pixels of FIG. 10 and luminance values. These are block diagrams which show the internal structure of the imaging device of 4th Embodiment. These are the circuit diagrams which show the other structure of the pixel in the solid-state imaging device with which the imaging device of this invention was equipped. These are the circuit diagrams which show the other structure of the pixel in the solid-state imaging device with which the imaging device of this invention was equipped. These are the circuit diagrams which show the other structure of the pixel in the solid-state imaging device with which the imaging device of this invention was equipped. These are circuit diagrams which show the structure of the pixel in the conventional solid-state imaging device. FIG. 18 is a timing chart showing the operation of the pixel in FIG. 17. These are the graphs which show the relationship between the output from the conventional solid-state imaging device, and sensor surface illumination.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Solid-state imaging device 2 Subtractor 3, 3a AD conversion part 4 Image processing part 5 Signal control part 6 Comparator 7 Buffer 8 Judgment part 9 Frame memory SW1, SW2 switch

Claims (9)

A photosensitive element that generates an electrical signal in accordance with the amount of incident light; a first transistor that is connected to the photosensitive element and generates an electrical signal in accordance with a photocharge from the photosensitive element and performs a reset operation; and In a solid-state imaging device having a pixel including an output unit that outputs an electrical signal from a transistor,
The pixel is
When light having a luminance value higher than the highest luminance value that can be converted as image data by the electric signal is incident on the photosensitive element from a second signal line different from the first signal line that supplies a DC voltage to the photosensitive element. A reset initial voltage supply unit that applies a first voltage value based on the residual charge generated in the photosensitive element to a connection portion between the photosensitive element and the first transistor;
When the pixel performs a reset operation,
After resetting the operating state of the first transistor, connecting the photosensitive element and the first transistor to reset the residual charge in the photosensitive element,
Immediately before resetting the residual charge in the photosensitive element, the reset initial voltage supply unit supplies the first voltage value to a connection portion between the photosensitive element and the first transistor. The pixel includes a switch that electrically contacts and separates the photosensitive element and the first transistor;
When the pixel performs an imaging operation, the switch is turned on to connect the photosensitive element and the first transistor,
When the pixel performs a reset operation, the switch is turned off to disconnect the photosensitive element and the first transistor to reset the operating state of the first transistor, and then the switch is turned on to switch the photosensitive element to the photosensitive element. The residual charge in the photosensitive element is reset after connecting the first transistor and supplying the first voltage to a connection portion between the photosensitive element and the first transistor by the reset initial voltage supply unit. The solid-state imaging device according to claim 1. A first electrode connected to the photosensitive element; a control electrode connected to the first electrode and outputting the electrical signal; a second electrode receiving a ternary voltage signal; With
When the pixel performs an image pickup operation, the voltage value of the voltage signal applied to the second electrode of the first transistor is set to be at least part of the high luminance side of the luminance range in which the image pickup is possible. The third voltage value to operate,
When resetting the operating state of the first transistor, the voltage value of the voltage signal applied to the second electrode of the first transistor is a fourth voltage value that makes the first transistor conductive,
When the residual charge in the photosensitive element is reset, the voltage value of the voltage signal applied to the second electrode of the first transistor is a fifth voltage value that is a voltage value between the third and fourth voltage values. The solid-state imaging device according to claim 2. The reset initial voltage supply unit
A first electrode connected to the second signal line; a second electrode connected to a connection portion between the photosensitive element and the first transistor; and a control electrode to which a control signal for ON / OFF control is input. A second transistor that applies a voltage value from the second signal line to a connection portion between the photosensitive element and the first transistor when a control signal is applied to the control electrode to turn it on. The solid-state imaging device according to claim 1, wherein the solid-state imaging device is provided. Obtained by subtracting the image data and the correction data from the solid-state imaging device that outputs the electrical signal obtained during the imaging operation as image data and the electrical signal obtained after the reset as correction data, and the solid-state imaging device An image pickup apparatus comprising: a subtractor that outputs the received image signal;
The said solid-state imaging device is a solid-state imaging device in any one of Claims 1-4, The imaging device characterized by the above-mentioned. Obtained by subtracting the image data and the correction data from the solid-state imaging device that outputs the electrical signal obtained during the imaging operation as image data and the electrical signal obtained after the reset as correction data, and the solid-state imaging device In an imaging apparatus comprising: a subtractor that outputs the image signal obtained; and a signal processing unit that performs signal processing on the image signal from the subtractor,
The solid-state imaging device is the solid-state imaging device according to any one of claims 1 to 4,
A comparator that compares the value of the correction data output from the solid-state imaging device with a reference value;
A determination unit that determines whether or not to output the image signal from the subtractor according to a comparison result in the comparator;
An imaging apparatus comprising: In the determination unit, when the comparison result in the comparator confirms that the value of the correction data is a value in a luminance range that greatly changes with respect to the luminance value,
The image pickup apparatus according to claim 6, wherein the image signal set to a value corresponding to a maximum luminance value is processed and output instead of the image signal from the subtractor. A memory storing the correction data in advance;
In the determination unit, when the comparison result in the comparator confirms that the value of the correction data is a value in a luminance range that greatly changes with respect to the luminance value,
Rather than the image signal from the subtracter, the image data obtained by subtracting the image data output from the solid-state imaging device and the correction data stored in the memory are processed and output. The imaging apparatus according to claim 6.   The correction data stored in the memory is correction data when the value of the correction data becomes a value in a luminance range that is substantially constant with respect to a luminance value according to a comparison result in the comparator. The imaging device according to claim 8.

Images