JP2006270356A - Solid-state image pickup element and solid-state image pickup device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a solid-state image pickup element in which a color filter is arranged in each pixel so that a high-resolution image can be acquired, and to provide an solid-state image pickup device. <P>SOLUTION: In the solid-state image pickup element 210, each pixel 212 is configured by combining a main photosensitive portion 214 having an optical sensor of an area enough to obtain incident light at high sensitivity and a sub-photosensitive portion 216 having an optical sensor of an area smaller than that of the main photosensitive portion 214 in order to obtain incident light at low sensitivity. The main photosensitive portion 214 is provided with a primary color filter 220 and the sub-photosensitive portion 216 is provided with a complementary color filter 224, and a main image signal and a sub-image signal are outputted from the photosensitive portions 214 and 216, respectively, thereby obtaining an image having high sensitivity and high reproducibility. A sub-microlens 222 in the sub-photosensitive portion 216 is formed to be small to give a margin to a pixel layout and pixels can be preferentially arranged. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a solid-state imaging device and a solid-state imaging device in which a color filter is arranged in each pixel.

  Conventionally, in a solid-state imaging device, in order to obtain an image with a high dynamic range, an image sensor in which a high-sensitivity pixel and a low-sensitivity pixel are arranged as a pair is used, and the amount of each signal obtained from these pixels is signaled. By processing, imaging in a high dynamic range is realized.

  In the solid-state imaging device described in Patent Document 1, a high dynamic range is realized by using two photosensitive pixels as one set and using a sensitivity difference between the two photosensitive pixels.

JP-A-4-298175

  The solid-state imaging device described in Patent Document 1 described above forms pixels with different sensitivities by changing the pixel size. Here, low photosensitive pixels are used to achieve a high dynamic range. A high-resolution image cannot be obtained. As described above, the solid-state imaging device cannot obtain an image with high sensitivity and high color reproducibility, that is, a high-resolution image, when taking an image.

  An object of the present invention is to provide a solid-state imaging device and a solid-state imaging device in which a color filter is arranged in each pixel so that a high-resolution image can be obtained by eliminating the drawbacks of the conventional technology.

  According to the present invention, a plurality of pixels that are arranged in the row and column directions and photoelectrically convert an object scene image each have a predetermined sensitivity and perform photoelectric conversion. In a solid-state imaging device configured by combining a sub-photosensitive portion having low sensitivity, the main photosensitive portion includes a main microlens having a high light collection rate, and a primary color filter that is a color filter of green, red, or blue The sub-photosensitive portion includes a sub-micro lens having a lower light collection rate than the main micro lens, and a complementary color filter that is a color filter of magenta, cyan, or yellow.

  A plurality of pixels arranged in the row and column directions and photoelectrically converting the object scene image each have a predetermined sensitivity and a lower sensitivity than the main photosensitive portion. In a solid-state imaging device that includes an imaging unit configured to be combined with a sub-photosensitive unit and outputs an image signal corresponding to a signal charge read by the plurality of pixels, the main photosensitive unit is a main microlens having a high light collection rate. , And a primary color filter that is one of green, red, and blue color filters, and the sub-photosensitive portion has a sub-microlens that has a lower light collection rate than the main microlens, and one of magenta, cyan, and yellow A complementary color filter which is a color filter is provided.

  As described above, according to the solid-state imaging device of the present invention, in each pixel, the high-sensitivity main photosensitive portion is provided with the primary color filter, and the low-sensitivity sub-photosensitive portion is provided with the complementary color filter. By adding the signals, an image with high resolution can be obtained.

  Further, in the solid-state imaging device of the present invention, the condensing rate of the sub-photosensitive portion may be lowered, so that the aperture size of the sub-microlens can be reduced, and there is a margin in the pixel layout. The aperture size of the main microlens can be increased, and the pixels can be arranged preferentially.

  In the solid-state imaging device to which the solid-state imaging device of the present invention is applied, an optimum image can be obtained by separately processing image signals based on signal charges read from the main photosensitive portion and the sub-photosensitive portion. .

  Next, embodiments of a solid-state imaging device according to the present invention will be described in detail with reference to the accompanying drawings.

  As shown in FIG. 1, the solid-state imaging device 10 of the embodiment includes a plurality of pixels 12 each including a primary photosensitive portion 14 having a primary color filter and a secondary photosensitive portion 16 having a complementary color filter. By outputting the main image signal and the sub image signal from each of the photosensitive portions, an image with high resolution and color reproducibility is generated.

  In the present embodiment, as shown in FIG. 1, the plurality of pixels 12 are arranged in a square matrix at a constant pitch in the row direction and the column direction, respectively, but are shifted in positions in the row direction and the column direction. Alternatively, a honeycomb arrangement may be used. In the solid-state imaging device 10, a large number of pixels are actually arranged. However, in FIG. 1, only a small number of pixels are illustrated in order to avoid complication.

  The pixel 12 generates incident image light by receiving incident light and photoelectrically converting it with an optical sensor such as a photodiode. As shown in FIG. 1, a main photosensitive portion 14 having a primary color filter 20, and The sub-photosensitive unit 16 including the complementary color filter 24 is included.

  When the main photosensitive portion 14 and the auxiliary photosensitive portion 16 of this embodiment have microlenses and optical sensors of the same size, as shown in FIG. 2, a signal amount with respect to the incident light amount can be obtained. Here, the signal amount in the main photosensitive portion 14 is indicated by a line 102, and the signal amount in the sub photosensitive portion 16 is indicated by a line 104. Further, since the main photosensitive portion 14 and the auxiliary photosensitive portion 16 have the same size photosensors, it is assumed that the same saturation signal amount can be obtained.

  As shown in FIG. 2, the signal amount 102 in the main photosensitive portion 14 does not reach the saturation signal amount unless a relatively large amount of incident light is obtained, but the signal amount 104 in the sub-photosensitive portion 16 has a relatively small amount of incident light. The amount of saturation signal can be reached by obtaining the amount of light. This is because the main photosensitive portion 14 has a small amount of incident light passing through the primary color filter 20 having a relatively low transmittance, and the sub-photosensitive portion 16 passes through the complementary color filter 24 having a relatively high transmittance. This is because there is a lot of incident light. For example, the complementary color filter 24 has a transmittance approximately twice that of the primary color filter 20.

  As shown in FIGS. 1 and 3, the main photosensitive unit 14 includes a microlens (ML) 18, a primary color filter 20, and an optical sensor 26, and the auxiliary photosensitive unit 16 includes ML 22, A complementary color filter 24 and an optical sensor 28 are provided. In this embodiment, the ML 22 of the auxiliary photosensitive unit 16 is smaller than the ML 18 of the main photosensitive unit 14. In this embodiment, the optical sensor 26 of the main photosensitive unit 14 and the optical sensor 28 of the auxiliary photosensitive unit 16 are configured with the same opening size so that the same saturation signal amount can be obtained. In FIGS. 1 and 3, MLs 18 and 22 and photosensors 26 and 28 are arranged at equal intervals, but are arranged in consideration of the incident angle of incident light with respect to each pixel position. Also good.

  As shown in FIG. 1, the solid-state imaging device 10 of the present embodiment includes a main photosensitive portion 14 having a green primary color filter, that is, a first pixel having a G photosensitive portion, and a main photosensitive portion having a red primary color filter. Part 14, that is, a second pixel having an R photosensitive part, and a main photosensitive part 14 having a blue primary color filter, that is, a third pixel having a B photosensitive part. The configuration is the same as that of the pixel 12 except for the filter. The solid-state imaging device 10 is arranged in a so-called G stripe RB complete checkered pattern in which the first pixels are arranged in a stripe pattern, and the second pixels and the third pixels are arranged in a checkered pattern therebetween. The

  In this embodiment, the first pixel has a sub-photosensitive portion 16 having a magenta complementary color filter, that is, an Mg photosensitive portion, and the second pixel has a sub-photosensitive portion 16 having a cyan complementary color filter. That is, it has a Cy photosensitive portion, and the third pixel is configured to have a secondary photosensitive portion 16 having a yellow complementary color filter, that is, a Ye photosensitive portion. However, the primary color filter and the complementary color filter in the first, second, and third pixels may not be this combination.

  Further, in the solid-state imaging device 10, when the plurality of pixels 12 are arranged using a honeycomb arrangement, the first pixels are arranged in a square lattice shape, and the second pixels are arranged diagonally across the first pixels. Alternatively, they may be arranged in a so-called honeycomb type G square lattice RB complete checkered pattern arranged in a complete checkered pattern in which the third pixels are arranged.

  Next, the operation when incident light is incident on the solid-state imaging device 10 of this embodiment will be described with reference to the cross-sectional view of FIG. In the solid-state imaging device 10, a large number of pixels are actually arranged, but in FIG. 2, in order to avoid complication, a second pixel having an R photosensitive portion and a Cy photosensitive portion, a G photosensitive portion, and an Mg photosensitive portion. Only the first pixel with

  For example, incident light incident on the R photosensitive portion is collected by the ML 18, passes through the red primary color filter 20, and is received by the optical sensor 26. On the other hand, incident light incident on the Cy photosensitive portion is collected by the ML 22, passes through the cyan primary color filter 24, and is received by the optical sensor 28.

  In this embodiment, as shown in FIG. 2, in the R photosensitive portion, a relatively large amount of incident light is condensed because ML 18 is large, but those that can pass through the red primary color filter 20 with low transmittance are as follows. Less likely to reach the optical sensor 26. On the other hand, in the Cy photosensitive portion, since the ML 22 is small, only a relatively small amount of incident light is collected. However, there are many that can pass through the cyan complementary color filter 24 having a high transmittance, so that the light sensor 28 is likely to be reached.

  Therefore, in the solid-state imaging device 10 of the present embodiment, the ML 18 of the main photosensitive portion 14 is set so that the signal amounts 102 and 104 in the main photosensitive portion 14 and the auxiliary photosensitive portion 16 become the target signal amount 106 shown in FIG. The ML 22 of the sub-photosensitive portion 16 is made smaller and adjusted to be configured. For example, the solid-state imaging device 10 may be configured with the ratio of the sizes of MLs 18 and 22 being 2: 1.

  Here, in the solid-state imaging device 10 of the present embodiment, when the main photosensitive portion 14 and the sub-photosensitive portion 16 have the same size photosensor and obtain the same incident light amount, as shown in FIG. A signal amount with respect to the aperture size of the microlens is obtained. Here, the amount of signal in the main photosensitive portion 14 is indicated by a line 112, and the amount of signal in the auxiliary photosensitive portion 16 is indicated by a line 114. The main photosensitive portion 14 and the auxiliary photosensitive portion 16 have optical sensors of the same size. To obtain the same saturation signal amount.

  For example, as shown in FIG. 4, when both the main photosensitive unit 14 and the sub photosensitive unit 16 desire a predetermined target signal amount 116, the main photosensitive unit 14 opens an opening that is about half the size of the sub photosensitive unit 16. If the microlens is provided, the target signal amount 116 can be obtained.

  By the way, in the solid-state imaging device 10 of the present embodiment, each pixel is provided with a complementary color filter and has high sensitivity by utilizing the fact that the complementary color filter has a higher transmittance than the primary color filter, for example, approximately twice the transmittance. In addition, a high-saturated main photosensitive portion and a primary photosensitive filter and a low-sensitivity and low-saturated sub-photosensitive portion may be combined. At this time, the sizes of the microlenses in the main photosensitive section and the sub-photosensitive section are made the same, the sizes of the complementary color filter and the photosensor in the main photosensitive section are increased, and the sizes of the primary color filter and the photosensor in the subphotosensitive section are decreased. Configure.

  An embodiment in which the solid-state imaging device of the present invention is applied to a solid-state imaging device such as a digital camera will be described below.

  As shown in FIG. 5, the solid-state imaging device 50 of this embodiment takes in incident light from the object scene in the optical system 52 and operates the operation unit 54 to operate the system control unit 56, timing generator 58, optical The drive unit 60 and the imaging drive unit 62 control each unit, and the imaging unit 64 having the solid-state imaging device 10 captures this object scene image. The captured image is converted into a pre-processing unit 66, analog / digital (A / D) An apparatus that displays the image signal processed by the converter 68 and the signal processing unit 70 on the display unit 72 and records the image signal on the recording unit 74. Note that portions not directly related to understanding the present invention are not shown and redundant description is avoided.

  Although a specific configuration is not illustrated in the optical system 52, there are a lens, an aperture adjustment mechanism, a shutter mechanism, a zoom mechanism, an automatic focus (AF) adjustment mechanism, an automatic exposure (AE) adjustment mechanism, and the like. In accordance with the drive signal 136 from the optical drive unit 60, the aperture adjustment mechanism, the shutter mechanism, the zoom mechanism, and the AF adjustment mechanism are driven to capture a desired object scene image and capture the image of the imaging unit 64. It is incident on the surface. In the following description, each signal is specified by the reference number of the connecting line in which it appears.

  The operation unit 54 is a manual operation device that inputs an operator's instruction, and supplies an operation signal 120 to the system control unit 56 in accordance with the operator's manual operation state, for example, a stroke operation of a shutter button (not shown). It has the function to do.

  The system control unit 56 is a control function unit having a central processing unit (CPU) that controls and supervises the operation of the entire apparatus in response to the operation signal 120 supplied from the operation unit 54. For example, according to the operation signal 120, the control signals 122, 124, 126 and 128 are supplied to the timing generator 58, the optical drive unit 60, the signal processing unit 70 and the recording unit 74 for control.

  The timing generator 58 includes an oscillator that generates a basic clock for operating the apparatus 50. In the present embodiment, the timing generator 58 is based on the control signal 122 supplied from the system control unit 56. And 134 are generated and supplied to the imaging drive unit 62, the preprocessing unit 66, and the A / D converter 68.

  The optical drive unit 60 generates a drive signal 136 corresponding to the control signal 124 and thereby drives the optical system 52, and the imaging drive unit 62 generates a drive signal 138 corresponding to the timing signal 130 and generates this signal. Is used to drive the imaging unit 64.

  The imaging unit 64 includes the solid-state imaging device 10 of the present invention as shown in FIG. 1 and has a function of photoelectrically converting an object scene image formed on the solid-state imaging device 10 into an electric signal 140. For example, any image sensor such as a charge coupled device (CCD) or a metal oxide semiconductor (MOS) may be used. The imaging unit 64 of the present embodiment is controlled by the drive signal 138 from the imaging drive unit 62, photoelectrically converts incident light incident from the object scene in each photosensitive unit, and the signal charge obtained thereby is converted into an analog electrical signal. Convert to signal 140 and output.

  The preprocessing unit 66 includes a correlated double sampling circuit (Correlated Double Sampling: CDS), a gain control amplifier (GCA), and the like, and is controlled by the timing signal 132 from the timing generator 58 to generate an image. Analog signal 140 is subjected to analog signal processing to generate and output an analog image signal 142.

  The A / D converter 68 quantizes the signal level of the input analog image signal 142 with a predetermined quantization level in accordance with the timing signal 134 from the timing generator 58, converts the signal level into a digital image signal 146, and outputs the digital image signal 146. .

  The signal processing unit 68 performs digital signal processing on the input digital image signal 144 in accordance with the control signal 126 from the system control unit 56. The digital image signals 146 and 148 generated thereby are displayed on the display unit. 72 and the recording unit 74, respectively.

  The signal processing unit 68 of the present embodiment is configured as shown in FIG. 6, and among the input digital image signal 144, the main image signal 150 based on the output from the main photosensitive unit 14, and the sub-photosensitive unit 16. Digital signal processing is performed on the sub-image signal 152 based on the output.

  Here, in the signal processing unit 68, the offset from the reference voltage level is corrected by the offset correction unit 80, the WB correction processing is performed by the white balance (WB) gain correction unit 82, and the gamma ( γ) The γ correction is performed by the correction unit 84, and the resultant image signal 154 is supplied to the pixel addition processing unit 94.

  Similarly, in the signal processing unit 68, the sub image signal 152 is processed by the offset correction unit 86, the WB gain correction unit 90, and the γ correction unit 92, and the resulting image signal 156 is supplied to the pixel addition processing unit 94. In this embodiment, the sub-image signal 158 obtained by offset-correcting the sub-image signal 152 is processed by the RGB conversion unit 88 and the resulting image signal 160 is supplied to the WB gain correction unit 90.

  The RGB conversion unit 88 of the present embodiment converts the image signal 160 indicating the primary color image based on the sub-image signal 158 from the offset correction unit 86, generates the image signal 160, and outputs the image signal 160 to the WB gain correction unit 90.

  Further, the pixel addition processing unit 94 generates an image signal 162 obtained by adding the input image signals 154 and 156 for each pixel, and further, the image signal 162 is synchronized by the synchronization processing unit 96. The correction processing unit 98 executes other correction processing such as black and white correction.

  The display unit 72 has a function of displaying an image based on the digital image signal 146 supplied from the signal processing unit 70. For example, a liquid crystal display (LCD) panel or the like is used.

  The recording unit 32 has a function of recording the digital image signal 148 supplied from the signal processing unit 70. For example, a memory card in which a semiconductor memory is mounted, a package containing a rotary recording body such as a magneto-optical disk, or the like. The information recording medium used may be included, and this information recording medium may be removable.

  Next, the operation of the solid-state imaging device 50 in this embodiment will be described. In the solid-state imaging device 50, when the operator operates the release button of the operation unit 54 and instructs to take a still image, for example, an operation signal 120 indicating a still image imaging instruction is supplied to the system control unit 56.

  In the system control unit 56, control signals 122, 124, and 126 indicating imaging instructions in response to the operation signal 120 are supplied to the timing generator 58, the optical driving unit 60, and the signal processing unit 70, respectively. In the timing generator 58, timing signals 130, 132, and 134 indicating an imaging instruction are generated according to the control signal 122, and supplied to the imaging driving unit 62, the preprocessing unit 66, and the A / D converter 68, respectively.

  The optical drive unit 60 generates a drive signal 136 corresponding to the control signal 124 to control the optical system 52, so that incident light from the object scene enters the image pickup unit 64, and the object scene image is solid-state imaged. An image is formed on the element 10.

  In the imaging drive unit 62, a drive signal 138 corresponding to the timing signal 130 is generated to drive the imaging unit 64. In the imaging unit 64, the signal charge is read by the solid-state imaging device 10 in response to the drive signal 138, and analog An electrical signal 140 is generated and supplied to the preprocessing unit 66.

  At this time, in the imaging drive unit 62, the drive signal 138 is generated in response to the timing signal 130 that causes the pulse to rise at a predetermined interval, and the signal charge from the main photosensitive unit 14 in response to the timing t1, as shown in FIG. It is preferable to generate a main drive signal 172 that reads the signal charge and a sub drive signal 174 that reads the signal charge from the sub-photosensitive portion 16 in accordance with the timing t2.

  The analog electrical signal 140 supplied to the preprocessing unit 66 is subjected to preprocessing such as CDS and GCA in accordance with the timing signal 132, and an analog image signal 142 is generated and supplied to the A / D converter 68. The analog image signal 142 supplied to the A / D converter 68 is converted into a digital image signal 144 according to the timing signal 134 and supplied to the signal processing unit 70.

  In the signal processing unit 70, the main image signal 150 is supplied to the offset correction unit 80 and the sub-image signal 152 is supplied to the offset correction unit 86 in the digital image signal 144 as shown in FIG.

  Here, the main image signal 150 is corrected by the offset correction unit 80, the WB gain correction unit 82, and the γ correction unit 84. As a result, an image signal 154 is generated and supplied to the pixel addition processing unit 94.

  The sub image signal 152 is first corrected by the offset correction unit 86, and the resulting sub image signal 158 is supplied to the RGB conversion unit 88. The sub image signal 158 is converted into an image signal 160 indicating an image in the primary color by the RGB conversion unit 88 and supplied to the WB gain correction unit 90. The image signal 160 is corrected by the WB gain correction unit 90 and the γ correction unit 92. As a result, an image signal 156 is generated and supplied to the pixel addition processing unit 94.

  In the pixel addition processing unit 94, the image signals 154 and 156 are subjected to addition processing for each pixel, and one image signal 162 is generated and supplied to the synchronization processing unit 96. The image signal 162 is corrected by the synchronization processing unit 96 and various correction processing units 98, and the resulting image signal is stored, for example, in a memory (not shown).

  In this way, the image signal subjected to the signal processing by the signal processing unit 70 is subjected to signal processing so that it can be handled by, for example, the display unit 72 or the recording unit 74 in accordance with the control signal 126 and displayed as the digital image signal 146. The digital image signal 148 is supplied to the recording unit 74.

  In the present invention, in the solid-state imaging device 50 to which the solid-state imaging device 10 is applied, when performing preview display or moving image shooting, the system control unit 56, for example, sends control signals 122, 124, and 126 for instructing moving image shooting, The signals are supplied to the timing generator 58, the optical drive unit 60, and the signal processing unit 70, respectively.

  The timing generator 58 supplies a timing signal 130 corresponding to the control signal 122 instructing moving image shooting to the imaging drive unit 62, and the imaging drive unit 62 supplies a drive signal 138 corresponding to the timing signal 130 to the imaging unit 64. Supply. At this time, in particular, the image pickup drive unit 62 may control the solid-state image pickup device 10 in the image pickup unit 64 by generating the drive signal 138 so that the signal charge is read only from the sub-photosensitive unit 16. For example, in the timing chart shown in FIG. 7, the imaging drive unit 62 may generate only the sub drive signal 174 as the drive signal 138.

  In addition, the imaging unit 64 generates an analog electrical signal 140 based on the signal charges read only from the sub-photosensitive unit 16, and the analog electrical signal 140 passes through the preprocessing unit 66 and the A / D converter 68. Are processed and supplied to the signal processing unit 70 as a digital image signal 144.

  In the signal processing unit 70, since the control signal 126 from the system control unit 56 instructs moving image shooting, the offset correction unit 80, the WB gain correction unit 82, and the γ correction unit 84 do not operate, and the offset correction unit 86, RGB conversion The unit 88, the WB gain correction unit 90, and the γ correction unit 92 operate to generate the image signal 156. The image signal 156 may be supplied directly to the synchronization processing unit 96 as the image signal 162 without being supplied to the pixel addition processing unit 94 and subjected to addition processing, but directly without being supplied to the pixel addition processing unit 94. Alternatively, the synchronization processing unit 96 may be supplied.

  As described above, in the solid-state imaging device 50 of the present embodiment, the signal charges can be read out from both the main photosensitive portion 14 and the sub-photosensitive portion 16 in the solid-state imaging device 10, and an image signal can be generated. The photosensitive member to be read can be selected so that the signal charge is read from the photosensitive portion or both photosensitive portions. For example, at the time of still image shooting, the photosensitive unit to be read is selected as only the main photosensitive unit 14 or both the main photosensitive unit 14 and the auxiliary photosensitive unit 16 to obtain a high-quality image. Can be selected only for the sub-photosensitive portion 16 and an image can be obtained by high-speed processing.

  In the solid-state imaging device 50 of the present embodiment, the readout target photosensitive unit is selected by the imaging drive unit 62, but the readout target photosensitive unit is selected by the system control unit 56, the timing generator 58, or a switching circuit (not shown). May be.

  In the solid-state imaging device 50, the readout target photosensitive unit may be switched during AE adjustment or AF adjustment. For example, at the time of AE adjustment and AF adjustment, luminance information and the like can be extracted easily and at high speed by using only the sub-photosensitive unit 16 as a reading target and using a signal obtained by adding adjacent pixels.

  By the way, in the solid-state imaging device 50, there are cases where addition reading or subtraction reading is performed in the solid-state imaging device during moving image shooting or AF adjustment. Therefore, in the solid-state imaging device 50 in which the readout target photosensitive part can be switched as in the present embodiment, when the readout target photosensitive part is only the secondary photosensitive part 16, for example, as shown in FIG. In the element 200, each pixel may be arranged, and a photosensitive portion including a green primary color filter may be disposed as the sub-photosensitive portion 16.

  In addition, the solid-state imaging device of the present invention can also enable imaging in a wide dynamic range by making the main photosensitive portion 14 highly sensitive and the sub-photosensitive portion 16 low sensitive. At this time, the solid-state imaging device is configured to obtain more information in consideration of the area distribution of the main photosensitive portion 14 and the auxiliary photosensitive portion 16 and the respective characteristics.

  For example, in another embodiment, as shown in FIG. 9, the solid-state imaging device 210 includes a main photosensitive unit 214 having a photosensor with a sufficient area to obtain incident light with high sensitivity, and incident light with low sensitivity. As shown in the figure, a sub-photosensitive portion 216 having an optical sensor with an area smaller than that of the main photosensitive portion 214 is provided. Further, the combination of the color filters in the main photosensitive portion 214 and the sub photosensitive portion 216 is not limited to that shown in FIG.

  For example, as shown in FIG. 10, the main photosensitive portion 214 and the auxiliary photosensitive portion 216 can obtain a signal amount with respect to the incident light amount, and are usually provided with a primary color filter and a main microlens having a predetermined aperture size. The main photosensitive portion of the conventional sub photosensitive portion having a sub-microlens having a primary color filter and having an aperture smaller than that of the main microlens is obtained by a line 304. It is assumed that the signal amount is obtained as shown.

  In addition, as shown by a line 306, the sub-photosensitive portion having a complementary color filter having a transmittance approximately twice that of the primary color filter has increased sensitivity and a saturation signal amount approximately twice that of the normal color filter. In addition, as shown by the line 308, the sub-photosensitive portion in which the aperture size of the sub-microlens is made smaller, the light collection rate is reduced, and a saturation signal amount equivalent to that when the primary color filter is used can be obtained. On the other hand, as shown by the line 310, the main photosensitive portion having the complementary color filter can obtain a saturation signal amount that is about twice that of a normal one. Further, the main photosensitive portion has a size of the aperture size of the main microlens. It is also possible to adjust the amount of signal obtained by adjusting, that is, adjusting the increase in the light collection rate.

  Therefore, in the solid-state imaging device 210 of the present embodiment, the main photosensitive portion 214 including the primary color filter 220 and the main microlens 218 having a large aperture size, and the subphotosensitive including the complementary color filter 224 and the sub microlens 222 having a small aperture size. By adjusting the size of the main micro lens 218 and the sub micro lens 222, it is possible to obtain an image with an ideal signal amount in a wide dynamic range, as indicated by a line 312 in FIG. it can.

  In addition, the solid-state imaging device 230 of the present invention may have a honeycomb arrangement in which each pixel is arranged with the positions shifted every other in the row direction and the column direction. In this case, as shown in FIGS. 11 and 12, the arrangement pattern of the main photosensitive portions in the solid-state imaging device 230 is such that the G photosensitive portions are arranged in a square lattice, and the R photosensitive portions are arranged diagonally across the G photosensitive portions. Alternatively, a so-called honeycomb-type G square lattice RB complete checkered pattern arranged in a complete checkered pattern where the B photosensitive portion is disposed may be used. In addition, as shown in FIGS. 11 and 12, the arrangement pattern of the sub-photosensitive parts is that the Mg photosensitive parts are arranged in a square lattice, and further, the Cy photosensitive part or the Ye photosensitive part is arranged diagonally across the Mg photosensitive part. The so-called honeycomb-type Mg square lattice CyYe perfect checkered pattern may be arranged on the perfect checkered pattern. At this time, as shown in FIG. 11, the rows of the Mg photosensitive portions may be arranged so as to be positioned on the rows of the G photosensitive portions. As shown in FIG. It may be arranged so as to be located on the row of parts.

  In the solid-state imaging device of the present invention, although the arrangement pattern of each pixel is not illustrated, the first pixels are arranged in a checkered pattern, and the second pixel and the third pixel are vertically aligned with the first pixel. And each row and each column of the matrix may be a Bayer pattern arranged to include any of the first pixel, the second pixel, and the third pixel. At this time, the combination of the color filters in the main photosensitive portion and the secondary photosensitive portion is not particularly limited.

It is a top view which shows one Example of the solid-state image sensor which concerns on this invention. It is a graph which shows the relationship of the signal amount with respect to the incident light quantity in the solid-state image sensor of the Example shown in FIG. It is explanatory sectional drawing which shows a part of solid-state image sensor of the Example shown in FIG. It is a graph which shows the relationship of the signal amount with respect to the microlens aperture size in the solid-state image sensor of the Example shown in FIG. It is a block diagram which shows the Example of the solid-state imaging device to which the solid-state image sensor of the Example shown in FIG. 1 is applied. FIG. 6 is a block diagram illustrating a signal processing unit in the solid-state imaging device of the embodiment illustrated in FIG. 5. 6 is a timing chart illustrating the operation of the solid-state imaging device according to the embodiment illustrated in FIG. 5. It is a top view which shows the other Example of the solid-state image sensor which concerns on this invention. It is a top view which shows the other Example of the solid-state image sensor which concerns on this invention. It is a graph which shows the relationship of the signal amount with respect to the incident light quantity in the solid-state image sensor of the other Example shown in FIG. It is a top view which shows the other Example of the solid-state image sensor which concerns on this invention. It is a top view which shows the other Example of the solid-state image sensor which concerns on this invention.

Explanation of symbols

10 Solid-state image sensor
12 pixels
14 Main photosensitive area
16 Secondary photosensitive section
18, 22 Micro lens
20 Primary color filters
22 Complementary color filter

Claims (11)

A plurality of pixels arranged in rows and columns and photoelectrically converting an object scene image each have a predetermined sensitivity and a main photosensitive portion that performs photoelectric conversion, and a sub-photosensitive that has a lower sensitivity than the main photosensitive portion. In the solid-state imaging device configured by combining the unit, the solid-state imaging device,
The main photosensitive portion includes a main microlens having a high light collection rate, and a primary color filter that is a color filter of green, red, or blue.
The solid-state imaging device, wherein the sub-photosensitive unit includes a sub-microlens having a lower light collection rate than the main microlens, and a complementary color filter that is a color filter of any one of magenta, cyan, and yellow. The solid-state imaging device according to claim 1, wherein the main photosensitive portion increases an area of an opening that receives incident light in order to increase sensitivity.
The sub-photosensitive portion has a smaller area of the opening than the main photosensitive portion in order to reduce the sensitivity,
The main microlens is formed with a larger opening size than the sub-microlens.   3. The solid-state imaging device according to claim 1, wherein a pixel including the main photosensitive portion provided with the green color filter as the primary color filter is a first pixel, and the red color filter is provided as the primary color filter. In addition, when the pixel including the main photosensitive portion is a second pixel and the pixel including the main photosensitive portion including the blue color filter as the primary color filter is a third pixel, the plurality of pixels are arranged in a row. Each of which is arranged in a square matrix at a constant pitch in each of the direction and the column direction, the first pixels are arranged in a stripe shape, and the second pixels and the third pixels are arranged in a checkered pattern between them. A solid-state image sensor that is arranged in a G checkered RB perfect checkered pattern.   3. The solid-state imaging device according to claim 1, wherein a pixel including the main photosensitive portion provided with the green color filter as the primary color filter is a first pixel, and the red color filter is provided as the primary color filter. In addition, when the pixel including the main photosensitive portion is a second pixel and the pixel including the main photosensitive portion including the blue color filter as the primary color filter is a third pixel, the plurality of pixels are arranged in a row. Using a honeycomb arrangement in which every other position is shifted in the direction and the column direction, the first pixels are arranged in a square lattice shape, and the second pixels or A solid-state imaging device, which is arranged in a so-called honeycomb-type G square lattice RB complete checkered pattern arranged in a complete checkered pattern in which third pixels are arranged.   3. The solid-state imaging device according to claim 1, wherein a pixel including the main photosensitive portion provided with the green color filter as the primary color filter is a first pixel, and the red color filter is provided as the primary color filter. When the pixel including the main photosensitive portion is a second pixel and the pixel including the main photosensitive portion including the blue color filter as the primary color filter is a third pixel, the plurality of pixels are 1 pixel is arranged in a checkered pattern, and the second pixel and the third pixel are surrounded by the first pixel in the top, bottom, left, and right, and each row and each column of the matrix are the first pixel, the second pixel, and A solid-state imaging device, arranged in a Bayer pattern, arranged to include any of the third pixels. A plurality of pixels arranged in rows and columns and photoelectrically converting an object scene image each have a predetermined sensitivity and a main photosensitive portion that performs photoelectric conversion, and a sub-photosensitive that has a lower sensitivity than the main photosensitive portion. A solid-state imaging device including an imaging unit configured to output image signals corresponding to signal charges read by the plurality of pixels.
The main photosensitive portion includes a main microlens having a high light collection rate, and a primary color filter that is a color filter of green, red, or blue.
The solid-state imaging device, wherein the sub-photosensitive unit includes a sub-microlens having a light collection rate lower than that of the main microlens, and a complementary color filter that is a color filter of magenta, cyan, or yellow. The solid-state imaging device according to claim 6, wherein the main photosensitive portion increases an area of an opening that receives incident light in order to increase sensitivity.
The sub-photosensitive portion has a smaller area of the opening than the main photosensitive portion in order to reduce the sensitivity,
The main microlens is formed with a larger opening size than the sub-microlens.   8. The solid-state imaging device according to claim 6, wherein a pixel including the main photosensitive portion provided with the green color filter as the primary color filter is a first pixel, and the red color filter is provided as the primary color filter. In addition, when the pixel including the main photosensitive portion is a second pixel and the pixel including the main photosensitive portion including the blue color filter as the primary color filter is a third pixel, the plurality of pixels are arranged in a row. Each of which is arranged in a square matrix at a constant pitch in each of the direction and the column direction, the first pixels are arranged in a stripe shape, and the second pixels and the third pixels are arranged in a checkered pattern between them. A solid-state imaging device that is arranged in a G checkered RB perfect checkered pattern.   8. The solid-state imaging device according to claim 6, wherein a pixel including the main photosensitive portion provided with the green color filter as the primary color filter is a first pixel, and the red color filter is provided as the primary color filter. In addition, when the pixel including the main photosensitive portion is a second pixel and the pixel including the main photosensitive portion including the blue color filter as the primary color filter is a third pixel, the plurality of pixels are arranged in a row. Using a honeycomb arrangement in which every other position is shifted in the direction and the column direction, the first pixels are arranged in a square lattice shape, and the second pixels or A solid-state imaging device, which is arranged in a so-called honeycomb-type G square lattice RB complete checkered pattern arranged in a complete checkered pattern in which the third pixel is arranged. 8. The solid-state imaging device according to claim 6, wherein a pixel including the main photosensitive portion provided with the green color filter as the primary color filter is a first pixel, and the red color filter is provided as the primary color filter. When the pixel including the main photosensitive portion is a second pixel and the pixel including the main photosensitive portion including the blue color filter as the primary color filter is a third pixel, the plurality of pixels are:
The first pixels are arranged in a checkered pattern, and the second pixel and the third pixel are surrounded by the first pixels at the top, bottom, left, and right, and each row and each column of the matrix are the first pixel and the second pixel. A solid-state imaging device, wherein the solid-state imaging device is arranged in a Bayer pattern arranged so as to include any one of the third pixel and the third pixel. 11. The solid-state imaging device according to claim 6, wherein the device performs signal processing on a main image signal based on a signal charge read from the main photosensitive portion among the image signals. Means,
Sub-image processing means for performing signal processing on the sub-image signal based on the signal charge read from the sub-photosensitive portion of the image signal;
An addition processing means for adding the image signal output from the main image processing means and the image signal output from the sub-image processing means;
And a post-addition signal processing means for performing signal processing on the image signal output from the addition processing means.

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