JP2010130289A - Solid-state imaging apparatus, semiconductor integrated circuit and defective pixel correction method - Google Patents

Abstract

In a conventional solid-state imaging device, since a video signal that has been added and read out from a pixel is corrected using adjacent pixels after reading out, there is a problem that correction that causes unnaturalness is performed. .
In a pixel addition unit 1105 that outputs a signal obtained by adding a plurality of pixel signals from a solid-state imaging device 1101, a storage unit 1102 that stores position information of pixel defects in the solid-state imaging device 1101, and a pixel addition unit 11105 A defect that corrects a defect in a video signal read out by pixel addition by using the number of pixels to be added, the number of defective pixels included in the pixel to be added, and the defect signal level included in the pixel output after the addition. And a pixel correction unit, so that correction processing is performed without using adjacent pixels after the target pixel is read.
[Selection] Figure 1

Description

  The present invention relates to a solid-state imaging device for imaging using a solid-state imaging device, a semiconductor integrated circuit suitable for correcting defective pixels of the solid-state imaging device, and a defective pixel correction method, and more specifically, a plurality of pixel signals are added. The present invention relates to a solid-state imaging device, a semiconductor integrated circuit, and a defective pixel correction method.

  In recent years, solid-state imaging devices such as digital still cameras and digital video cameras have become widespread. In these solid-state imaging devices, the number of pixels of the solid-state imaging device has been increased, and in recent years, a system of millions of pixels has been generally used, and products with tens of millions of pixels are also commercially available. It has become.

  Furthermore, in the function of digital still cameras, models that use a high-pixel solid-state imaging device not only for still image use but also for moving image shooting have become mainstream. In a digital still camera also used for moving image shooting, processing is performed using all pixel signals of a solid-state image sensor as in conventional cases when using a still image. An imaging method that adds and reads out pixel signals may be used.

  In a solid-state imaging device such as a CCD or CMOS, it is known that local sensitivity failure of a semiconductor occurs in a two-dimensionally arranged pixel during or after the manufacturing process. When these phenomena occur, it becomes impossible to obtain a charge output according to the amount of incident light, so that it appears as a so-called defective pixel in which white spots and black spots can be seen on the captured image regardless of the subject.

  In recent years, the number of pixels required for solid-state imaging devices has increased from the previous hundreds of thousands of pixels to several million pixels, and in some cases tens of millions of pixels. In other words, the probability of occurrence of defective pixels appearing in the solid-state imaging device has not decreased. In particular, in a solid-state imaging device used for a consumer device that requires low cost, in order to increase the manufacturing yield, it is necessary to allow a larger number of defective pixels than in the past.

  Therefore, there is a demand for correction processing for defective pixels.

  Conventionally, in order to correct the image quality degradation caused by the imaging output of such defective pixels by signal processing, the position information of the defective pixels included in the solid-state imaging device is stored in a nonvolatile memory, and this nonvolatile memory is used during normal imaging. The defective pixel is identified according to the position information stored in the memory, or the signal level difference with the adjacent pixel is evaluated, and if a difference exceeding the set level occurs, the defective pixel is identified, and the defective pixel The defective pixel correction is performed by replacing the imaging output of the above with the imaging output of the pixel output by the same color filter adjacent to the defective pixel.

  In still image applications, even when there is a defect in a video signal obtained by an imaging method that reads out all pixel signals from a solid-state image sensor as in the past, imaging is performed by adding pixel signals from multiple pixels and reading them when using moving images. The same technique is used for defects in the video signal obtained by this method.

  In some solid-state image sensors that use an imaging method that adds and reads pixel signals from a plurality of pixels, if the pixel is a defective pixel, the pixel signal is added by replacing it with an adjacent pixel before adding the pixel signal. A technique for preventing defective pixels from being included in a later video signal is also used.

  In the conventional technique, correction of a defective pixel is realized by replacing it with an imaging output of a pixel output by the same color filter adjacent to the defective pixel. In these imaging methods that read out all pixel signals of a solid-state image sensor, it is possible to replace the pixel signal of a pixel adjacent to a defective pixel on the solid-state image sensor, so the characteristics of the replaced pixel are evaluated. By realizing replacement with the optimal neighboring pixels, it is possible to realize effective correction that is visually inferior (see, for example, Patent Document 1).

  However, in the case of using an imaging method in which pixel signals are added and read from a plurality of pixels, the video signal obtained from the solid-state imaging device is a signal after adding the pixel signals of the plurality of pixels. Even if the output positions are adjacent to each other, there is a distance at the pixel position of the solid-state imaging device, and it can be said that the pixels are non-adjacent pixels. In such a defect correction method for replacing non-adjacent pixels, there is a problem that the possibility of visually uncomfortable feeling is increased, so that it cannot be said to be appropriate correction.

In addition, in an imaging method in which pixel signals are added and read out from a plurality of pixels, a video signal obtained from a solid-state image sensor is detected from a plurality of pixels in order to eliminate that the solid-state image sensor is not adjacent in terms of pixel position. It has also been proposed to change the imaging method for adding and reading out pixel signals and adding after replacing the adjacent pixels on the solid-state imaging device (see, for example, Patent Document 2). Since it is necessary to change the configuration of the image sensor, there is a problem that it cannot be applied to a solid-state image sensor that has been conventionally used.
JP2002-344814 Japanese Patent No. 3740324

  As described above, in the correction of the defective pixel in the imaging method in which the pixel signals are added and read from the plurality of pixels, the distance between the defective pixel and the replacement pixel is not a replacement with the adjacent pixel at the pixel position of the solid-state imaging device. There is a problem that the correction is likely to be physically separated and unnatural, or a solid-state imaging device in which the pixel addition method is changed needs to be recreated.

  The present invention has been made in view of the problems as described above, and in an imaging-type solid-state imaging device that adds and reads out pixel signals from a plurality of pixels, the configuration of a conventional solid-state imaging element is significantly changed. An object of the present invention is to make it possible to correct a pixel defect that is less likely to feel visually uncomfortable.

  (1) A solid-state imaging device of the present invention includes a pixel addition unit that adds and outputs pixel signals from pixels of a solid-state imaging device, a storage unit that stores defective pixel information regarding defective pixels of the solid-state imaging device, Based on the number of pixels to which the pixel signal is added by the pixel addition unit, the number of defective pixels included in the pixel to be added, and the signal level of the defective pixel included in the output signal output from the pixel addition unit, A defective pixel correction unit that corrects the defect.

  The defective pixel correction unit calculates an average level of pixel signals of pixels other than the defective pixel by subtracting the signal level of the defective pixel included in the signal level of the output signal (video signal) output from the pixel addition unit. The average level is preferably corrected by multiplying the number of pixels to be added.

  According to the solid-state imaging device of the present invention, the defect included in the output signal (video signal) after addition output from the pixel addition unit is determined based on the number of added pixels, the number of defective pixels, and the signal level of the defective pixel. Since the output signal itself can be corrected, another output signal (video signal) after addition, that is, a non-adjacent pixel that is adjacent in output position but has a distance in the solid-state image sensor pixel position It is not necessary to make corrections using the output signal (video signal) according to the above, thereby making the correction visually inferior, and there is no need to change the configuration of the solid-state imaging device.

  (2) In one embodiment of the solid-state imaging device of the present invention, the defective pixel information includes information on the position and signal level of the defective pixel in the solid-state imaging device.

  According to this embodiment, the defective pixel correction unit can correct a defect in the output signal after addition output from the pixel addition unit based on the position information of the defective pixel and the signal level information of the defective pixel.

  (3) In another embodiment of the solid-state imaging device of the present invention, the defective pixel correction unit is output from an addition pixel number determination unit that determines the number of pixels to be added by the pixel addition unit, and the pixel addition unit. A defective pixel position determining means for determining an output signal including a pixel signal of a defective pixel as an output signal of a pixel at a position; and a defective pixel content number for determining the number of defective pixels included in the output signal Determining means; defective signal level determining means for determining the signal level of the defective pixel included in the output signal; the added pixel number determining means; the defective pixel position determining means; the defective pixel content number determining means; And a defective pixel correction executing means for performing a correction process of the defect of the output signal based on the determination result of the means.

  The number of added pixels in the image pickup method that adds and reads out pixel signals from a plurality of pixels is uniquely determined according to the image pickup method of the solid-state image pickup device. The number of added pixels can be determined based on which operation method is used.

  The method of adding a plurality of pixels can be uniquely determined according to the specifications of the solid-state imaging device, and the defective pixel position determination unit is configured to detect from the plurality of pixels based on the position information of the defective pixels in the video method of reading all pixels. It is possible to determine pixel position information of defective pixels when read by an imaging method that adds and reads the pixel signals.

  The defective pixel content number determining means is configured to output the defective pixel to the output signal output from the pixel addition unit based on the position information of the defective pixel in the video method for reading out all pixels and the mixing (addition) method of the pixel addition unit. It can be determined whether or not a pixel signal is included and how many defective pixel signals are included.

  The defective signal level determination unit is included in the output signal output from the pixel addition unit based on the signal level of the defective pixel output from the solid-state imaging device and the number of defective pixels obtained from the defective pixel content determination unit. The signal level of the defective pixel can be determined.

  According to this embodiment, it is possible to determine a numerical value necessary for performing defective pixel correction and correct the defect with an output signal of only the target pixel that is added and output. It is not necessary to use an output signal of a pixel adjacent to the pixel, and correction that is visually inferior is possible.

  In addition, since the addition pixel number determination means determines the number of pixels to be added by the pixel addition unit, it is possible to specify which addition method is used even when there are a plurality of types of addition methods in the pixel addition unit. Thus, the number of pixels to be added can be determined.

  (4) In the embodiment of the above (3), the defective pixel position determination means determines which one based on the position information of the defective pixel in the method of reading out the pixel signals of all pixels and the pixel addition method of the pixel addition unit. It may be determined whether it is output as an output signal of the pixel at the position.

  According to this embodiment, when the pixel addition method in the pixel addition unit is changed by using the position information of the defective pixel in the method of reading out the pixel signals of all pixels, that is, the absolute position information on the solid-state imaging device. Even if it exists, it can respond, and the position of the defective pixel after addition can be specified.

  (5) In the embodiment of the above (4), the defective pixel content number judging means determines how many defective pixels are included in the output signal output from the pixel adder based on the judgment result of the defective pixel position judging means. It may be determined whether the pixel signal of the pixel is included.

  According to this embodiment, it is possible to correct a defective pixel regardless of how many defective pixels are included in the output signal of the target pixel that is added and output.

  (6) In the embodiment of (5), the defect signal level determination means is based on the signal level of the defective pixel of the solid-state imaging device and the number of defective pixels obtained from the defect pixel content number determination means. The signal level of the defective pixel included in the output signal output from the pixel adder may be determined.

  According to this embodiment, the signal level of a defective pixel with high reliability can be calculated regardless of how many defective pixels are included in the output signal of the target pixel that is added and output.

  (7) In the embodiment of (3) above, the storage unit stores defect identification information that identifies the characteristics of a defective pixel, and the defect signal level determination means is based on the defect identification information. You may make it judge the signal level of the defective pixel contained in the output signal output from the said pixel addition part.

  According to this embodiment, when the defective pixel has a certain characteristic, it is possible to specify the signal level of the defective pixel by reflecting the characteristic of the defective pixel, and it is possible to realize a highly reliable calculation of the signal level of the defective pixel. .

  (8) In another embodiment of the solid-state imaging device of the present invention, the storage unit stores defect identification information that identifies the characteristics of the defective pixel.

  According to this embodiment, since information identifying the characteristics of defective pixels can be stored, highly reliable defective pixels can be corrected.

  (9) In the embodiment of (8) above, the defect identification information may be information identifying a defective pixel having a characteristic of outputting a fixed signal level.

  According to this embodiment, since the information specifying the signal level of the defective pixel can be stored, highly reliable defect correction can be performed.

  (10) In the above embodiment (8) or (9), management means for managing whether or not to perform correction by the defective pixel correction unit based on the defect identification information may be provided.

  According to this embodiment, it becomes possible to designate a defective pixel to be corrected based on the defect identification information, and partial defect correction can be performed.

  (11) In the embodiment of (10) above, the management unit may manage the defective pixel correction unit so that the correction by the defective pixel correction unit is a correction according to the characteristics of the defective pixel.

  According to this embodiment, the defect correction method can be changed according to the characteristics of the defective pixel, that is, the type of the defective pixel, and effective defective pixel correction can be performed.

  (12) In the solid-state imaging device of the present invention, a pixel addition unit that adds a pixel signal from a pixel of the solid-state imaging device by clipping with a predetermined clip value, and using the clip-processed pixel as a defective pixel, Included in the storage unit for storing defective pixel information regarding defective pixels, the number of pixels to which pixel signals are added by the pixel addition unit, the number of defective pixels included in the pixels to be added, and the output signal output from the pixel addition unit And a defective pixel correction unit that corrects a defect in the output signal based on a signal level of the defective pixel, and the defective pixel correction unit determines the number of pixels to be added by the pixel addition unit. And a defective pixel position determining means for determining which position of the output signal including the pixel signal of the defective pixel output from the pixel adding unit is output as an output signal of the pixel. A defective pixel content number judging means for judging the number of defective pixels included in the signal, a defective signal level judging means for judging the signal level of the defective pixel contained in the output signal based on the predetermined clip value, and the addition A defective pixel correction execution unit that performs a correction process of the defect of the output signal based on the determination results of the pixel number determination unit, the defective pixel position determination unit, the defective pixel content number determination unit, and the defect signal level determination unit. Yes.

  According to the solid-state imaging device of the present invention, it is possible to specify a clip value as a signal level of a defective pixel when clipping is performed and a signal level higher than a certain value is not handled. Can be realized.

  (13) The solid-state imaging device of the present invention includes a pixel addition unit that adds and outputs a pixel signal from a pixel of a solid-state imaging device having a defective pixel whose signal level changes depending on imaging conditions, and a defective pixel of the solid-state imaging device A storage unit that stores defective pixel information regarding the pixel number of pixels to which the pixel addition unit adds pixel signals, the number of defective pixels included in the pixel to be added, and a defect included in the output signal output from the pixel addition unit A defective pixel correction unit that corrects a defect of the output signal based on a signal level of the pixel, and the defective pixel information includes a position of the defective pixel in the solid-state imaging device, a signal level, and an imaging condition when storing the defective pixel Information.

  According to the solid-state imaging device of the present invention, when a defective pixel has a certain characteristic, the signal level of the defective pixel can be specified by reflecting the characteristic of the defective pixel, and the signal level of the defective pixel with high reliability can be specified. Can be calculated.

  (14) In the embodiment of (13), the defective pixel information includes information on the signal characteristics of the defective pixels that change in accordance with the imaging conditions, and the defective pixel correction unit includes information on the signal characteristics of the defective pixels. The signal level of the defective pixel included in the output signal output from the pixel adding unit may be determined based on the imaging condition.

  According to this embodiment, since it is possible to store the characteristics of defective pixels based on imaging conditions such as light quantity, temperature, and light source, correction of defective pixels that dynamically change depending on the characteristics based on imaging conditions is realized. can do.

  (15) The semiconductor integrated circuit according to the present invention includes a storage unit that stores position information of defective pixels in the solid-state imaging device, and a pixel addition unit that adds pixel signals from the pixels of the solid-state imaging device. A defective pixel correction unit that corrects a defect of the output signal based on the number of defective pixels included in the pixel to be corrected and a signal level of the defective pixel included in the output signal output from the pixel addition unit, The defective pixel correction unit includes an addition pixel number determination unit that determines the number of pixels to be added by the pixel addition unit, and an output signal that includes the pixel signal of the defective pixel that is output from the pixel addition unit. A defective pixel position determining means for determining whether the output signal is output; a defective pixel content number determining means for determining the number of defective pixels included in the output signal; and a signal of the defective pixel included in the output signal. Defect signal level determining means for determining the level, the added pixel number determining means, the defective pixel position determining means, the defective pixel content number determining means and the defect signal level determining means based on the determination results of the defect of the output signal Defective pixel correction execution means for performing correction processing.

  According to the semiconductor integrated circuit of the present invention, when a system is configured using a solid-state imaging device including a pixel defect, a pixel addition process is performed to correct a defect in the read video signal, and peripheral pixels are corrected. It is possible to provide a small-sized system that realizes image processing using a signal with less discomfort.

  (16) The defective pixel correction method of the present invention includes an adding step of adding and outputting pixel signals from the pixels of the solid-state imaging device, a storing step of storing position information of the defective pixels in the solid-state imaging device, and the adding step. An addition pixel number determination step for determining the number of pixels to be added in step, a defective pixel position determination step for determining which position of the output signal output in the addition step is output as the pixel output signal, and the addition A defective pixel content number determining step for determining the number of defective pixels included in the output signal output in the step, and a defective signal level determining step for determining a signal level of the defective pixel included in the output signal output in the adding step; , The added pixel number determining step, the defective pixel position determining step, the defective pixel content number determining step, and the defective signal level determining step. Based on the determination result of step, and a defective pixel correction step of performing correction processing of the defect of the output signal output by said adding step.

  According to the defective pixel correction method of the present invention, the defect included in the output signal after the addition in the addition step is corrected by the output signal itself based on the number of added pixels, the number of defective pixels, and the signal level of the defective pixel. Therefore, it is not necessary to perform correction by using an output signal obtained by adding pixel signals of non-adjacent pixels. This makes correction that is visually inferior, and also requires changing the configuration of the solid-state imaging device. Nor.

  According to the present invention, by adding the pixel signals from a plurality of pixels and correcting the read output signal itself, the pixel signals of non-adjacent pixels that are physically separated are added. There is no need to make corrections using the read output signal, which reduces the possibility of visual unnaturalness, and changes the pixel addition method by changing the configuration of the solid-state image sensor There is no need to do.

  In this way, there is no need to significantly change the configuration of the conventional solid-state imaging device itself. Therefore, by improving the configuration at low cost, an imaging method for reading out all pixel signals and adding pixel signals from a plurality of pixels are added. It is possible to realize effective improvement of defective pixel correction in a solid-state imaging device that uses both of the readout imaging methods.

 As a result, in the field of solid-state imaging devices where the number of pixels is increasing, in order to increase the manufacturing yield, it is possible to tolerate a larger number of defective pixels than in the past, and to provide a low-cost solid-state imaging device in consumer equipment It becomes possible to do.

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

(Embodiment 1)
FIG. 1 is a configuration diagram of a solid-state imaging device according to an embodiment of the present invention.

  The solid-state imaging device according to this embodiment converts a video light input from the lens 1100 into an electrical signal, and outputs a solid-state imaging device 1101 and a video signal (pixel signal) of a plurality of pixels of the same color read from the solid-state imaging device 1101. A pixel addition unit 1105 that performs addition processing, a storage unit 1102 that stores defective pixel position information as defective pixel information regarding a defective pixel, a defective pixel correction unit 1103 that performs correction processing of defective pixels, and predetermined image processing (WB processing) AE processing, YC processing, etc.) to convert the video signal into an appropriate output image.

  The solid-state imaging device further includes one or more CPUs 1107, a volatile memory 1108 such as a RAM, and a non-volatile memory 1109 such as a ROM and a flash memory. A program stored in the non-volatile memory 1109 is stored in the solid-state imaging device. By executing the control, each unit such as the solid-state imaging device 1101, the pixel addition unit 1105, the storage unit 1102, the defective pixel correction unit 1103, and the image processing unit 1104 is controlled.

  The solid-state imaging device 1101 has pixel regions arranged two-dimensionally, has a function of converting video light input from the lens 1100 into an electrical signal, and outputs a video signal (pixel signal) of each pixel. Read operation is performed.

  The pixel addition unit 1105 outputs a pixel addition video signal (output signal) obtained by performing addition processing using a plurality of pixels of the same color of the video signal read out by the solid-state imaging device 1101. Note that the pixel addition unit 1105 may be realized as a function of the solid-state imaging device 1101, that is, the solid-state imaging device 1101 may be configured to include the pixel addition unit 1105. In addition, the pixel addition unit 1105 may be realized by AFE (Analog Front End) for analog processing and ADC (AD Converter) for conversion into a digital signal, or may exist independently.

  The solid-state imaging device of this embodiment can selectively operate an imaging method for reading out pixel signals from all pixels of the solid-state imaging device 1101 and an imaging method for adding and reading out pixel signals using a plurality of pixels.

  The storage unit 1102 includes a defective pixel position that is position information in a two-dimensionally arranged pixel area of a defective pixel that is included in the solid-state imaging device 1101 and cannot convert incident video light into a normal electrical signal. Information is determined, and the determined information is stored in the storage area as an information table related to the defective pixel.

  The defective pixel position information is absolute defective pixel position information in the solid-state imaging device 1101 and is information that does not vary, and thus can be used repeatedly. The defective pixel position information is not intended for temporary use, but is stored in a non-volatile storage area of the storage unit 1102 for long-term use, so that it can be used repeatedly.

  The defective pixel position information is detected at the manufactured semiconductor factory and stored in advance in a non-volatile storage area of the storage unit 1102, or the solid-state imaging device shutter is in a light-shielded state on the solid-state imaging device side. Sometimes, pixel information that does not reach the predetermined output level (black point defective pixel) when the positional information of the pixel exceeding the predetermined output level (white point defective pixel) and the incident light quantity to the solid-state imaging device are set to the predetermined level A method of storing the position information in a non-volatile storage area of the storage unit 1102 can be used.

  The defective pixel position information stored here is the position information of the defective pixel in the two-dimensionally arranged pixel region, that is, the position information of the defective pixel obtained by the imaging method of reading all the pixels.

  The reason why the solid-state imaging device can store data not only at the time of shipment of the solid-state imaging device is to deal with a defective pixel that occurs later.

  The defective pixel correction unit 1103 includes the number of added pixels in the pixel adding unit 1105 and the number of defective pixels included in the video signal read out after addition as an output signal from the pixel adding unit 1105 (hereinafter referred to as “defective pixel content number”). And a correction gain and a correction offset for the video signal calculated using a signal level occupied by defective pixels included in the video signal read after addition (hereinafter also referred to as “defect level”). Then, a correction process for defective pixels in the pixel-added signal is performed. The defective pixel correction unit 1103 can refer to information on defective pixels stored in the storage unit 1102 and storage conditions for storage.

  Note that the semiconductor integrated circuit 1106 can include the storage unit 1102, the defective pixel correction unit 1103, and the image processing unit 1104. As a result, it is possible to construct a miniaturized system that performs effective defect correction in a solid-state imaging device that receives a pixel-added video signal.

  FIG. 2 is a block diagram of the storage unit 1102 and the defective pixel correction unit 1103.

  The storage unit 1102 includes defective pixel information storage means 1301. The defective pixel information storage unit 1301 stores information for specifying a defective pixel (hereinafter also referred to as “defective pixel information”). The defective pixel information here means defective pixel position information. As defective pixel information, it is also possible to store a defect signal level possessed by the pixel of interest and an imaging condition when the defective pixel information is stored, for example, brightness, temperature, brightness, and the like. Such defective pixel information can be referred to and utilized over a long period of time by storing it in a nonvolatile memory or the like as the defective pixel information storage unit 1301.

  The defective pixel correction unit 1103 includes an addition pixel number determination unit 1201, a defective pixel position determination unit 1202, a defective pixel content number determination unit 1203, a defect signal level determination unit 1204, and a defective pixel correction execution unit 1205. Yes.

  The addition pixel number determination unit 1201 specifies the number N of pixel signals to be added in the solid-state image sensor 1101. The number of added pixels N in the imaging method that adds and reads out pixel signals from a plurality of pixels is information that is uniquely determined according to the imaging method of the solid-state imaging device 1101. Therefore, since the information can be specified by determining the operation method of the solid-state image sensor 1101, the number of added pixels N is calculated by determining which operation method the solid-state image sensor 1101 is operated. To do. The addition pixel number determination method includes, for example, saving the operation mode value set when operating the pixel addition unit 1105 to a storage area or the like, and referring to the pixel addition number managed by the pixel addition unit 1105. It may be possible to refer to.

  The defective pixel position determination unit 1202 specifies the pixel of which position in the read video signal is output after the defective pixel addition process. The method of adding a plurality of pixels can be uniquely determined according to the specifications of the solid-state image sensor 1101. In other words, based on the position information of the defective pixel in the video method for reading out all pixels, it is possible to calculate the pixel position information of the defective pixel when read out by the imaging method of reading out by adding pixel signals from a plurality of pixels. Is possible. As a defective pixel position determination method, for example, it is conceivable to perform position coordinate conversion using defective pixel information stored in the storage unit 1102 and an addition method in the pixel addition unit 1105.

  The defective pixel content number judgment unit 1203 calculates the number of contained defective pixels. That is, it is specified that the target pixel is a pixel generated including M defective pixels. Whether or not the pixel of interest includes a defective pixel and how many pixels it includes can be specified by calculating based on positional information of a defective pixel in a video method for reading all pixels and a mixing method of pixel mixture. As the defective pixel content number determination method, for example, the position coordinate conversion is performed by using the defective pixel information stored in the storage unit 1102 and the addition method in the pixel addition unit 1105 to correspond to the converted position coordinates. A method for obtaining the number of defective pixels is conceivable.

  The defect signal level determination unit 1204 calculates the defect level of the pixel signal.

  The defective signal level determining unit 1204 adds pixel signals from a plurality of pixels using the signal level of the defective pixel output from the solid-state imaging device and the defective pixel number M obtained from the defective pixel content number determining unit 1203. Then, pixel readout is performed by an imaging method of reading out, and the output video signal specifies the signal level of the defective pixel possessed. As a defective signal level determination method, for example, all signal components of each defective pixel included in a pixel read out by pixel addition are added. If the signal component of the defective pixel is a uniquely determined value, the defective signal level is uniquely determined. A method is conceivable in which the value is obtained by integrating the defective pixel number M obtained from the defective pixel content number judging means 1203.

  The defective pixel correction execution unit 1205 corrects the defective pixel based on the values calculated by the added pixel number determination unit 1201, the defective pixel position determination unit 1202, the defective pixel content number determination unit 1203, and the defect signal level determination unit 1204, respectively. A correction value for the video signal input to the unit 1103 is determined, and defective pixels are corrected by gain processing and offset processing.

  It should be noted that the arithmetic processing performed in the added pixel number judging means 1201, the defective pixel position judging means 1202, the defective pixel content number judging means 1203, the defect signal level judging means 1204, and the defective pixel correction performing means 1205 ( In this embodiment, the calculation is assumed to be performed using a CPU included in the solid-state imaging device, but may be performed using an arithmetic unit such as a CPU outside the solid-state imaging device.

  FIG. 3 is a diagram illustrating an image of pixel addition in the pixel addition unit 1105.

The pixel addition process is a method of outputting a signal obtained by adding a plurality of pixels, instead of individually reading out all the pixels of the solid-state imaging device 1101. For example, in the case of generating one signal by adding the signals of four pixels, one pixel is generated by adding the signal levels of adjacent pixels of the same color obtained by the same color filters of the pixels 301, 302, 303, and 304. , A method of outputting as the pixel 305. At this time, by multiplying the coefficients by the position information of the pixels 301, 302, 303, and 304, the signals before addition may be weighted and added. Various methods can be considered for the addition method, but it can be said that the addition method can be specified if the readout method is determined. Even when a solid-state imaging device that can only read out all pixels is used, by providing an AFE or ADC, a pixel addition means is provided in the AFE or ADC, and a video signal subjected to pixel addition is output. It doesn't matter.
FIG. 4 is a diagram illustrating a configuration of defective pixel correction processing in the defective pixel correction execution unit 1205 of the defective pixel correction unit 1103.

  The defective pixel correction unit 1103 corrects the video signal output from the pixel addition unit 1105 in the defect correction execution unit 1205, and outputs a corrected signal. The offset processing unit 1401 removes the defect signal level from the input video signal. As the offset value used in the offset processing, the signal level calculated by the defect signal level determination unit 1204 is used. By this processing, the defect signal level is removed from the input video signal.

  Next, the gain processing unit 1402 performs N pixel addition processing with a signal level averaged with the signal level of pixels that are not defective. That is, it can be said that the average value of effective video signals of the target pixel is calculated, and pixel addition processing is performed using this average value as the value of the defective pixel. Note that the average value is calculated using only pixels of a valid video signal, and does not include the number of defective pixels. The gain value in the gain processing is obtained by using the added pixel number N and the defective pixel content number M obtained by the added pixel number judgment unit 1201, the defective pixel position judgment unit 1202, and the defective pixel content number judgment unit 1203, N / ( NM).

  Based on FIG. 5 and FIG. 6, an image of occurrence of a defect in the readout method using pixel addition will be described.

  As described above, pixel addition processing is a method of generating one video signal by adding a plurality of pixels. As shown in FIG. 5, when none of the R1 signal, R2 signal, R3 signal, and R4 signal is a defective pixel, the video signals (pixel signals) of 4 pixels having these normal levels are added together. The output R signal is generated and output as a pixel signal having a normal signal level.

  Next, as shown in FIG. 6, a case where the R1 pixel is a defective pixel in the R1, R2, R3, and R4 signals is considered. That is, since the R1 defect signal, the R2 signal, the R3 signal, and the R4 signal are added, the output R signal is generated and output as a defective pixel signal including the level of the R1 defect signal. Become.

  In the conventional method, the pixel is replaced with the adjacent pixel after being read by the imaging method in which the pixel signals are added and read from the plurality of pixels. However, in the present invention, this output is performed without using the adjacent pixel. The defect is removed by correcting the pixel signal itself.

  A defective pixel correction process performed by the defective pixel correction execution unit 1205 will be described with reference to FIG.

  The output signal Sig output from the pixel addition unit 1105 is a video signal that is read from the solid-state imaging device 1101 and read by performing N pixel addition processing by the pixel addition unit 1105. The output signal Sig includes M pixel defects. When the level of the output signal Sig is represented by Sig and the defect level is represented by Kizu, the defect level included in the output signal level, that is, the signal total level of M pixels, is removed by Sig-Kizu, and excellent pixels (NM) are obtained. The signal level can be only.

  Next, the average level of excellent pixel (NM) signals, Sig-Kizu / (NM), is used as the signal level of one pixel before pixel addition. In other words, this value is corrected with the correct signal level that the defective pixel should originally have. By obtaining a signal level Sig-Kizu / (N-M) * N when N pixels are added with a pixel having a signal level of Sig-Kiz / (N-M), the defective signal of the defective pixel is not included. Correction can be performed using the signals of pixels adjacent to each other in the pixel array.

  More specifically, based on FIG. 6 described above, the output signal R is a signal that is output after an addition process of four pixels (N = 4). The output signal R includes 1 of the R1 defect. Pixel (M = 1) defect is included.

  Therefore, the signal level (Kizu) of the R1 defect is removed from the signal level (Sig) of the output signal R (Sig-Kizu), and only the signal levels of the three pixels R2, R3, and R4 which are excellent pixels are obtained. Next, the average level (Sig-Kizu) / 3 of the signals of the three pixels that are excellent pixels is calculated, and four pixels are added to obtain {(Sig-Kizu) / 3} × 4, the corrected signal. It is.

  As described above, since the defective pixel can be corrected only by the output signal Sig output from the pixel addition unit 1105, the pixel position of the solid-state image sensor has a distance even if the output position is adjacent. Compared to the conventional example in which the pixel signal of the pixel is replaced with the output signal after addition, the appropriate correction is less likely to cause a visually uncomfortable feeling. Moreover, there is no need to change the configuration of the solid-state imaging device.

  The defect signal level total Kizu is a value calculated by the defect signal level determination unit 1204, M is a value calculated by the defective pixel content number determination unit 1203, and N is calculated by the addition pixel number determination unit 1201. The process is performed using the determined value. Further, the defective pixel position determining means 1202 calculates that the output signal level Sig is a pixel including a defect.

  Next, storage of defective pixels will be described with reference to FIG.

  As described above, the storage unit 1102 has a function of storing defective pixel position information. A defective pixel is a pixel that cannot achieve a function for reading a normal signal generated at an arbitrary position on the solid-state image sensor 1101.

  The pixels are arranged two-dimensionally horizontally and vertically, and each pixel can be read out independently. Whether or not the pixel of interest is a defective pixel depends on whether it is a pixel (white point defective pixel) that exceeds a predetermined output level when the shutter of the solid-state imaging device is in a light-shielded state, and whether the pixel is incident on the solid-state imaging device It is specified whether the pixel does not reach a predetermined output level (black spot defective pixel) when the light quantity is set to a predetermined level. The predetermined output level at this time can be arbitrarily determined.

  The pixel determined to be a defective pixel is stored in the storage unit 1102 including a non-volatile memory at the pixel position. For example, when the target pixel 801 is determined to be a defective pixel in the storage unit 1102, the storage unit 1102 stores information on the position information of the pixel 801 (vertical, horizontal) = (0, 1). This information is stored in a nonvolatile memory and managed in a state where it can be used for a long time. For example, when four pixels (1, 2), (2, 1), (3, 2), (5, 5) other than the pixel 801 are also defective, five defective pixels including the pixel 801 The position information is stored in the storage unit 1102 and managed by a nonvolatile memory.

  The defective pixel position information stored in the storage unit 1102 is information that can be referred to in the defective pixel correction unit 1103. The added pixel number determination unit 1201, the defective pixel position determination unit 1202, the defective pixel content number determination unit 1203, the defect signal The level determination unit 1204 refers to the defective pixel position information and performs necessary calculation processing.

  Further, in the storage unit 1102, not only the position information of the target pixel but also information such as the signal level of the defective pixel of the target pixel (hereinafter, also referred to as “defective pixel signal level”) and imaging conditions are attached as information regarding the defective pixel. And memorize it. In addition, information regarding these defective pixels can be freely referred to by the defective pixel correction unit 1103 and can be used for arithmetic processing.

  FIG. 9 shows a storage processing image when the storage unit 1102 stores the defective pixel signal level along with the defective pixel position information.

  For example, in the storage unit 1102, the target pixel 901 has a signal level a. The determination of whether or not the pixel is a defective pixel is performed by determining whether the signal level of the target pixel is a pixel that exceeds a predetermined signal level A or does not reach a predetermined output level B. That is, when the signal level a of the target pixel 901 exceeds the predetermined signal level A or does not reach the predetermined signal level B, it is determined as a defective pixel, and defective pixel position information is stored. At this time, the signal level a of the target pixel 901 compared with the predetermined signal level A and the predetermined signal level B is information that can be grasped in the determination process of the defective pixel. That is, this information can also be stored in the storage unit 1102.

  When it is determined that the target pixel 901 is a pixel exceeding the predetermined signal level A, the information of the pixel position information (vertical, horizontal) = (0, 1) of the target pixel 901 and the signal level of the target pixel 901 are a Is stored in the storage unit 102. As a result, it is possible to store defective pixel position information and a defective pixel signal level associated therewith. The stored defective pixel position information and the defective pixel signal level are managed in the nonvolatile memory. In FIG. 9, the signal levels b, c, d, e are stored in the same manner for the four pixels (1, 2), (2, 1), (3, 2), (5, 5) other than the pixel 901. .

  The defective pixel position information stored in the storage unit 1102 is information that can be referred to in the defective pixel correction unit 1103. The added pixel number determination unit 1201, the defective pixel position determination unit 1202, the defective pixel content number determination unit 1203, the defect signal The level determination unit 1204 can perform necessary calculation processing with reference to the defective pixel position information. Note that the predetermined signal level A and the predetermined signal level B can be arbitrarily set.

  Further, if the determination is made based on the signal level of the target pixel 901, it is possible to store the defective pixel position information in the storage unit 1102 only for the pixel having the signal level of the video signal level of the target pixel α. At this time, the value of α can be arbitrarily set, and is information that can be referred to by each means of the defective pixel correction unit 1103.

(Embodiment 2)
FIG. 10 is a block diagram corresponding to FIG. 2 of another embodiment of the present invention.

  As in FIG. 1 of the above-described embodiment, the solid-state imaging device of this embodiment includes a lens 1100, a solid-state imaging device 1101, a pixel addition unit 1105, a storage unit 2102, a defective pixel correction unit 2103, and an image. The basic configuration is the same.

  In this embodiment, the storage unit 2102 includes a defect identifying unit 2001 having a function of identifying a defective pixel having a characteristic of outputting a fixed signal level in the solid-state imaging device 1101, and information on the defect identifying unit. And defective pixel type management means 2003 for storing defect identification information, and defective pixel information storage means 2301 for storing information for specifying defective pixels.

  Defective pixels are caused by various factors, and not all defects have the same characteristics. Therefore to identify what kind of a defect, it is necessary to perform a correction corresponding to the defect. When the pixel of interest is a defective pixel, the defect identifying unit 2001 identifies the characteristics of the pixel and the defect. For example, it is specified that the pixel is a defective pixel of a type that outputs a signal level of the maximum output level of the solid-state imaging device under any condition.

  The defective pixel type management unit 2003 has a function of managing defective pixel information to be stored in accordance with the characteristic of the defective pixel specified by the defect identifying unit 2001, and whether or not the defective pixel is a correction target at the time of pixel addition reading. It has a function to manage. For example, a defective pixel position information group composed only of defective pixels that always display a specific signal level F is created, and only a defective pixel that always displays a specific signal level E in a form distinguishable from it. It is possible to consider a form in which a defect pixel position information group is created, such as management in a form that can be distinguished here, and defect characteristic information added to the stored defective pixel position information and stored.

  Since the information managed by the defective pixel type management unit 1003 needs to be used for a long time, it can be stored in a non-volatile memory and used repeatedly.

  The defective pixel correction unit 2103 includes an addition pixel number determination unit 2201 that calculates the number of added pixels in the pixels read from the solid-state imaging device 1101, and a defective pixel position determination unit that calculates a read pixel position after the addition process of the defective pixels. 2202, a defective pixel content number determining unit 2203 for calculating the number of defective pixels included in the readout pixel after the addition process, and a defect signal level determining unit 2204 for calculating the defect signal level using the number of defective pixels and the defect signal level. A defect type determining unit 2002 for specifying the type of the defective pixel, and a defective pixel correction performing unit 2205 for correcting the defective pixel.

  The defective pixel correction unit 2103 is intended to correct the defective pixel appropriately. That is, it is required to read the defect type of each pixel of interest managed by the defective pixel type management unit 2003 in the storage unit 2102 and perform correction processing according to the defect type.

  The defect type determination unit 2002 reads the information managed by the defective pixel type management unit 2003, identifies the type of defective pixel of the target pixel to be corrected, and corrects the defect of the target pixel. Is notified to the defect signal level determination means 2204 and the defective pixel correction execution means 2205. The defect signal level determination unit 2204 and the defective pixel correction execution unit 2205 perform calculation of the defect signal level and correction processing of the defective pixel based on the unit obtained by the defect type determination unit 2002.

  For example, there is a defective pixel that has a defective pixel that always has a defective pixel that has a characteristic that always outputs a signal level that is uniquely determined, for example, the maximum value of the output range, and has a defective pixel that is always generated by a certain method Consider a case where the storage unit 2102 and the defective pixel correction unit 2103 are operated for the purpose of performing appropriate correction on these pixels.

  At this time, the coordinates of these defective pixels are stored by the storage unit 2102 using the defect identification unit 2001 having a function of identifying that the pixel of interest is a defect having a characteristic of always outputting a fixed signal level K. The position information is stored in a storage area such as a nonvolatile memory. Further, the correction in the defective pixel correction unit 2103 is performed using the defect type determination unit 2002 that specifies that the correction processing is always performed on the defective pixel generated by a certain method from the information acquired from the storage area such as the nonvolatile memory. Determine the means.

  At this time, the storage unit 2102 may store only defects having a characteristic of always outputting a fixed signal level K, or defects having a characteristic of always outputting a fixed signal level K. The information may be stored in a form that can be distinguished from other defects, for example, by assigning information that can be used to determine this, or by dividing the storage area.

  When the defect type determination unit 2002 determines that the defect type of the pixel of interest is a defect that has a characteristic of always outputting a fixed signal level K, the defect signal level determination unit 2204 is included in the pixel of interest. Treat one defect level as K. Here, the defective pixel content number judging means 2203 judges whether or not the contained defect is a defect having a characteristic that always outputs a fixed signal level K, and calculates the defective pixel number M. Is possible. When only defects having the characteristic of always outputting a fixed signal level K are corrected, the defect content number M includes only defects having the characteristic of always outputting a fixed signal level K. When it corresponds to a plurality of defects, it is calculated how many defects have the characteristic of always outputting a fixed signal level K. As a result, even when information on a plurality of types of defective pixels is stored in the storage area, it is possible to correct only defects having a characteristic of always outputting a predetermined signal level K. It is. In the defect signal level determination means 2204, when only defects having the characteristic of always outputting a predetermined signal level K are to be corrected, it is considered that M defects of level K are included, The defect level is calculated as K × M.

  Further, for example, in an imaging method in which pixel signals are added and read out from a plurality of pixels, solid-state imaging using an addition method having a characteristic of adding a video signal before addition after performing clip processing at a predetermined clip level C There are elements.

  As another embodiment, a case where such a solid-state imaging device is used will be described. In this case, when the read video signal exceeds the clip level C, the clipping process is performed by the clipping circuit, the video signal is output as the signal level C, and the addition process is performed. Therefore, the added video signal is C × N. Is guaranteed not to exceed. In addition, a signal having the clip level C or higher is processed as the clip level C and is not a normal signal level. Therefore, a signal having a signal level higher than the clip level C can be handled as a defective pixel.

  The defect identifying unit 2001 identifies that the target pixel is a pixel that outputs a video signal level equal to or higher than the clip level C, and stores the coordinate position information of the corresponding pixel in the storage area. At this time, a pixel that outputs a video signal level equal to or higher than the clip level C may be stored, or other defective pixels may be stored. However, in the case of storing a plurality of types of defective pixels, it is possible to store the defect by adding information that can be identified as a pixel restricted by the clip level C or by dividing the storage area. Perform processing that can identify the type.

  When the defect type determination unit 2002 reads and determines that the addition process is performed including a pixel whose target pixel is equal to or higher than the clip level C and outputs a video signal level, a defect is determined. The signal level determination unit 2204 processes one defect level included in the target pixel as C. Here, the defective pixel content number judging means 2203 judges whether or not the contained defect has the level of the clip level C, and calculates the number of this kind of defective pixel contained in the read pixel. Is possible. When only a defect having a clip level C is targeted for correction, it can be said that it is a defective pixel M.

  Due to the clip processing at the clip level C, a signal of the clip level C or higher from the solid-state imaging device does not flow to the subsequent processing unit. Therefore, it can be said that the signal clipped and output at the clip level C is a defective pixel having the signal level C. That is, it can be said that the defect signal level determination means 2204 can calculate the signal level of the defective pixel with C as the defect level of one pixel. Thereby, the defective pixel signal level is set to the clip level C, and the signal level of the defective pixel can be calculated based on the defect content number M.

(Embodiment 3)
FIG. 11 is a block diagram corresponding to FIG. 2 of still another embodiment of the present invention.

  Similar to FIG. 1 of the above-described embodiment, the solid-state imaging device of this embodiment includes a lens 1100, a solid-state imaging device 1101, a pixel addition unit 1105, a storage unit 3102, a defective pixel correction unit 3103, and an image. The basic configuration is the same.

  In this embodiment, correction of a defective pixel whose output signal level varies is considered. That is, consider correction for a defect when the signal level of a defective pixel changes in accordance with a change in imaging conditions.

  The solid-state imaging device has imaging conditions when imaging the video signal. For example, the light quantity, temperature, light source, etc. can be considered. Depending on these imaging conditions, the level of pixel signal accumulation in the solid-state imaging device changes. This characteristic that can be said in a normal pixel can be considered similarly for a defective pixel. In other words, it can be said that there is a type of defect in which the signal level of the defective pixel changes according to the imaging condition.

  The storage unit 3102 includes an imaging condition investigation unit 3101 that investigates an imaging condition at the time of storing defective pixels, an imaging condition management unit 3102 that stores an imaging condition obtained by the imaging condition investigation unit 3101, and a pixel that stores pixel signal characteristics A signal change characteristic storage unit 3103 and a defective pixel information storage unit 3301 for storing information for specifying a defective pixel are provided.

  The imaging condition investigation unit 3101 operates at the time of storing defective pixel information and at the time of imaging. The imaging condition investigation unit 3101 investigates and specifies an imaging condition at that time, and transmits information to the imaging condition management unit 3102.

  The imaging condition management unit 3102 stores the imaging condition obtained by the imaging condition investigation unit 3101 in the storage unit when storing the positional information of the defective pixel, and the imaging at the time of storing the defective pixel information stored in the storage unit during normal imaging. The conditions and the imaging conditions at the time of imaging are compared, and processing necessary for calculating the signal level of the defective pixel at the time of current imaging is obtained.

  The pixel signal change characteristic storage unit 3103 stores a signal change characteristic of a pixel in the solid-state imaging device. The signal change characteristic of the pixel is represented by an X-order function or the like, and the stored characteristic is used for pixel correction in the defective pixel correction unit 3103. The signal change characteristic of the pixel can be registered from the outside using a nonvolatile memory or the like, and the pixel signal change characteristic storage unit 3103 can read and use the registered signal change characteristic of the pixel. Shall.

  The defective pixel correction unit 3103 includes a defective pixel that calculates the number of added pixels in the pixel read from the solid-state imaging device, the read pixel position after the addition process of the defective pixel, and the number of defective pixels included in the read pixel after the addition process. The correction of the defective pixel is realized by using the number and the defect signal level.

  Here, the defect signal level includes the signal change characteristic specified by the pixel signal change characteristic storage unit 3103, the imaging condition at the time of normal imaging managed by the imaging condition management unit 3102, and the imaging condition at the time of storing defective pixel information. The defective signal level is specified using the defective pixel information stored in the defective pixel information storage means 3301. This defect signal level specifying function may be realized as a function of the defect signal level determination means 3204.

  FIG. 12 shows the change characteristics of the video signal depending on the imaging conditions.

  Assume that the signal level of the video signal changes depending on the imaging conditions as shown in FIG. Here, the imaging condition on the horizontal axis in FIG. 12 is, for example, an exposure amount. A characteristic represented by an Xth order function representing the change characteristic of the pixel signal level shown in FIG. 12 is stored in the pixel signal change characteristic storage means 3103. By using this change characteristic, it becomes possible to grasp the change of the defective pixel following the signal change accompanying the imaging condition of the image signal. In other words, if the pixel signal change characteristics are known, the video signal level of the defective pixel in the current imaging condition is determined by the current imaging condition, the imaging condition at the time of storing the pixel position information, and the video signal level of the defective pixel at the time of storing the pixel position information Can be calculated.

  As described above, in the storage unit 3102, in addition to the defective pixel position information, the imaging condition and the pixel signal change characteristic of the pixel at the time of imaging are stored, thereby calculating the pixel signal level possessed by the signal of the defective pixel. Is possible. Thereby, the defective pixel correction unit 3103 performs appropriate defect correction.

  The correction in the defective pixel correction unit 3103 will be further described.

  The defective pixel correction unit 3103 includes an additional pixel number determining unit 3201 that calculates the number of added pixels in the pixels read from the solid-state imaging device, a defective pixel position determining unit 3202 that calculates the read pixel position after the defective pixel is added, By the defective pixel content number judging means 3203 for calculating the number of defective pixels included in the readout pixel after the addition process, the defect signal level judging means 3204 for calculating the defect signal level using the number of defective pixels and the defect signal level, A defective pixel correction execution unit 3205 that realizes defective pixel correction based on the obtained information is provided.

  Here, the defect signal level determination unit 3204 obtains a calculation coefficient for calculating the defect signal level from the imaging condition management unit 3102 and calculates the defect signal level in the target pixel. Further, as shown in FIG. 4 described above, the processing of the defective pixel correction execution unit 3205 is performed by offset processing and gain processing for the pixel of interest, and adjacent pixels read after addition are not used.

  By these means, by obtaining the signal level of the defective pixel even for the type of defect whose signal level of the defective pixel changes according to the change of the imaging condition, the peripheral pixels after readout after the pixel addition processing are obtained. Without using it, it is possible to realize correction using only the effective signal included in the defective pixel of interest.

  The solid-state imaging device according to the present invention makes the user more uncomfortable by performing correction using the pixel addition target pixel without using the adjacent pixel after pixel addition in the solid-state imaging device that performs pixel addition. Correction of pixel defects not given is performed. This makes it possible to obtain a good correction result even when the adjacent pixels of the same color adjacent on the solid-state image sensor are likely to contain defects. In addition, when the value of the target pixel needs to be corrected as a defective pixel, it will not be significantly different from the value of the surrounding pixels. Even in such a case, a good correction result can always be obtained.

 As a result, it is possible to use a solid-state imaging device including a certain amount of defective pixels, which is useful for high-pixel digital still cameras, digital video cameras, network cameras, vehicle-mounted cameras, and the like.

It is a block diagram of the solid-state imaging device concerning this invention. It is a block diagram of the memory | storage part and defective pixel correction | amendment part of FIG. It is an image figure of pixel addition. It is a figure which shows the correction process of a defective pixel correction implementation means. It is a read image figure using pixel addition in case a defective pixel is not included. It is a read image figure using pixel addition in the case of including a defective pixel. It is an image figure of the correction process of a defective pixel. It is a figure for demonstrating the memory | storage of the defective pixel position information to a memory | storage part. It is a figure for demonstrating the memory | storage of the defective pixel position information and a defective pixel signal level to a memory | storage part. It is a block diagram corresponding to FIG. 2 of other embodiment of this invention. It is a block diagram corresponding to FIG. 2 of further another embodiment of this invention. It is a figure which shows the change characteristic by the imaging condition of a video signal.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1101 Solid-state image sensor 1102,2102,3102 Memory | storage part 1103,2103,3103 Defective pixel correction part 1104 Image processing part 1105 Pixel addition part 1106 Semiconductor integrated circuit 1201,2201,3201 Addition pixel number judgment means 1202,2202,3202 Defective pixel position Determining means 1203, 2203, 3203 Defect pixel content number determining means 1204, 2204, 3204 Defect signal level determining means 1205, 2205, 3205 Defect correction executing means 2001 Defect identifying means 2002 Defect type determining means 2003 Defect pixel type managing means 3101 Imaging conditions Investigation means 3102 Imaging condition management means 3103 Pixel signal change characteristic storage means

Claims (16)

A pixel adder that adds and outputs pixel signals from the pixels of the solid-state imaging device;
A storage unit for storing defective pixel information relating to defective pixels of the solid-state imaging device;
The output signal based on the number of pixels to which the pixel signal is added by the pixel addition unit, the number of defective pixels included in the pixel to be added, and the signal level of the defective pixel included in the output signal output from the pixel addition unit A defective pixel correction unit that corrects a defect of
A solid-state imaging device comprising:   The solid-state imaging device according to claim 1, wherein the defective pixel information includes information on a position of a defective pixel and a signal level in the solid-state imaging device. The defective pixel correction unit includes:
Addition pixel number determination means for determining the number of pixels to be added by the pixel addition unit;
A defective pixel position determination means for determining which position of the output signal including the pixel signal of the defective pixel output from the pixel addition unit is output as an output signal of the pixel;
A defective pixel content number judging means for judging the number of defective pixels included in the output signal;
A defect signal level determining means for determining a signal level of a defective pixel included in the output signal;
A defective pixel correction execution unit that performs a correction process of the defect of the output signal based on the determination results of the addition pixel number determination unit, the defective pixel position determination unit, the defective pixel content number determination unit, and the defect signal level determination unit;
The solid-state imaging device according to claim 1 or 2.   The defective pixel position determining means determines which pixel is output as an output signal of a pixel based on position information of a defective pixel in a method of reading out pixel signals of all pixels and a pixel addition method of the pixel addition unit. The solid-state imaging device according to claim 3 for determining.   The defective pixel content number determining means determines how many defective pixel signals are included in the output signal output from the pixel adder based on the determination result of the defective pixel position determining means. The solid-state imaging device according to claim 4.   The defective signal level determining means is included in the output signal output from the pixel adding section based on the signal level of the defective pixel of the solid-state imaging device and the number of defective pixels obtained from the defective pixel content number determining means. The solid-state imaging device according to claim 5, wherein a signal level of a defective pixel is determined. The storage unit stores defect identification information that identifies the characteristics of a defective pixel,
The solid-state imaging device according to claim 3, wherein the defect signal level determination unit determines a signal level of a defective pixel included in an output signal output from the pixel addition unit based on the defect identification information.   The solid-state imaging device according to claim 1, wherein the storage unit stores defect identification information that identifies a characteristic of a defective pixel.   The solid-state imaging device according to claim 8, wherein the defect identification information is information identifying defective pixels having a characteristic of outputting a fixed signal level.   The solid-state imaging device according to claim 8, further comprising a management unit that manages whether to perform correction by the defective pixel correction unit based on the defect identification information.   The solid-state imaging device according to claim 10, wherein the management unit manages the defective pixel correction unit such that the correction by the defective pixel correction unit is correction according to a characteristic of the defective pixel. A pixel adder that clips and adds pixel signals from the pixels of the solid-state imaging device with a predetermined clip value;
A storage unit that stores defective pixel information related to the defective pixel, using the clipped pixel as a defective pixel;
The output signal based on the number of pixels to which the pixel signal is added by the pixel addition unit, the number of defective pixels included in the pixel to be added, and the signal level of the defective pixel included in the output signal output from the pixel addition unit A defective pixel correction unit that corrects the defects of
The defective pixel correction unit includes:
Addition pixel number determination means for determining the number of pixels to be added by the pixel addition unit;
A defective pixel position determination means for determining which position of the output signal including the pixel signal of the defective pixel output from the pixel addition unit is output as an output signal of the pixel;
A defective pixel content number judging means for judging the number of defective pixels included in the output signal;
Defect signal level determination means for determining the signal level of the defective pixel included in the output signal based on the predetermined clip value;
A defective pixel correction execution unit that performs a correction process of the defect of the output signal based on the determination results of the addition pixel number determination unit, the defective pixel position determination unit, the defective pixel content number determination unit, and the defect signal level determination unit;
A solid-state imaging device comprising: A pixel adder that adds and outputs pixel signals from pixels of a solid-state image sensor having a defective pixel whose signal level changes depending on imaging conditions;
A storage unit for storing defective pixel information relating to defective pixels of the solid-state imaging device;
The output signal based on the number of pixels to which the pixel signal is added by the pixel addition unit, the number of defective pixels included in the pixel to be added, and the signal level of the defective pixel included in the output signal output from the pixel addition unit A defective pixel correction unit that corrects the defects of
The defective pixel information includes information on a position of a defective pixel in the solid-state imaging device, a signal level, and information on an imaging condition at the time of storing the defective pixel. The defective pixel information includes information on signal characteristics of defective pixels that change according to imaging conditions,
The solid pixel according to claim 13, wherein the defective pixel correction unit determines a signal level of a defective pixel included in an output signal output from the pixel addition unit based on information on signal characteristics of the defective pixel and an imaging condition. Imaging device. A storage unit for storing position information of defective pixels in the solid-state imaging device;
The number of pixels added by a pixel addition unit that adds pixel signals from the pixels of the solid-state imaging device, the number of defective pixels included in the pixel to be added, and the number of defective pixels included in the output signal output from the pixel addition unit A defective pixel correction unit that corrects a defect in the output signal based on a signal level;
The defective pixel correction unit includes:
Addition pixel number determination means for determining the number of pixels to be added by the pixel addition unit;
A defective pixel position determination means for determining which position of the output signal including the pixel signal of the defective pixel output from the pixel addition unit is output as an output signal of the pixel;
A defective pixel content number judging means for judging the number of defective pixels included in the output signal;
A defect signal level determining means for determining a signal level of a defective pixel included in the output signal;
A defective pixel correction execution unit that performs a correction process of a defect of the output signal based on the determination results of the addition pixel number determination unit, the defective pixel position determination unit, the defective pixel content number determination unit, and the defect signal level determination unit; A semiconductor integrated circuit provided. An addition step of adding and outputting pixel signals from the pixels of the solid-state imaging device; and
A storage step of storing position information of defective pixels in the solid-state imaging device;
A defective pixel position determination step of determining which position of the output signal output in the addition step is output as a pixel output signal;
A defective pixel content number determining step of determining the number of defective pixels included in the output signal output in the adding step;
A defect signal level determination step of determining a signal level of a defective pixel included in the output signal output in the addition step;
Based on the determination results of the addition pixel number determination step, the defective pixel position determination step, the defective pixel content number determination step, and the defect signal level determination step, a defect correction process for the output signal output in the addition step is performed. A defective pixel correction step;
A defective pixel correction method comprising:

Images