JP2008005137A - Solid-state imaging device and imaging system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a solid-state imaging device and an imaging system that suppress distortions of image and can be obtained with a compact, low-cost, and low-power-consumption constitution. <P>SOLUTION: The solid-state imaging device includes photodetection units 1 which are formed in a semiconductor substrate and accumulates luminance information, corresponding to the photodetection quantity of incident light and an imaging unit 3, where the plurality of photodetection units 1 are disposed in two dimensions, the photodetection units 1 being disposed varying interval of an array, going from the center to the outer periphery of the imaging unit 3. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a solid-state imaging device and an imaging system capable of improving lens aberration and the like.

  In recent years, mobile phones, surveillance cameras, and in-vehicle cameras have become thinner (thinner), and it has become difficult to ensure quality in terms of image quality, such as the effect of lens aberration. In particular, in-vehicle cameras require wide-angle imaging in order to increase the ability to collect information around the automobile. In such a situation, distortion that is most likely to be affected is distortion. Aberrations in lens design include spherical aberration, coma aberration, astigmatism, field curvature, and distortion aberration, which are called Seidel's five aberrations, and there is no optical system that optimizes all of these.

  In general lens design, spherical aberration, coma aberration, astigmatism, and field curvature are optimized, and distortion is often sacrificed. This distortion varies depending on the optical conditions, but when a square square is imaged, the light is condensed into an elliptical shape called barrel distortion (or four vertices are reduced) and the four sides called pincushion are reduced. (Or the four vertices expand). This is because the optical path incident on the outer periphery of the imaging surface becomes larger than the optical path incident on the center of the imaging surface.

As a countermeasure for this distortion, in general,
(1). Make the lens symmetrical. That is, the same type of lens is used for the front lens (lens close to the subject) and the rear lens (lens close to the solid-state imaging device).

    (2). Use a matching lens. That is, a convex lens is matched with a concave lens, and a concave lens is matched with a convex lens.

(3). Correction is performed using an image processing LSI.
Such improvement measures are taken. Usually, it is possible to substantially suppress distortion by the above three means.

  However, with respect to (1) and (2) above, an increase in the number of lenses becomes an impediment to lowering the height and causes an increase in the price of the entire camera system. In addition, the above (3) also requires an image processing LSI, which causes an increase in power consumption and a price increase. Thus, the realization of a method capable of improving the distortion while reducing both the number of lenses and the image processing LSI and reducing the size and size is an important issue.

  Hereinafter, distortion and conventional measures will be described with reference to the drawings.

  FIG. 7 shows the state of distortion. FIG. 7A shows a state in which incident light is irradiated to the sensor unit 704 of the image sensor via the rear lens 701. As shown in FIG. 7A, in the case where the rear lens 701 is configured by a convex lens and is focused once in front of the rear lens 701 (hereinafter referred to as a front focus), the front focus is used. When entering the rear lens 701, the light traveling around the rear lens 701 deviates from the ideal condensing optical path 703 due to coma and travels along the optical path 702 outside the lens center. Therefore, the optical image of the subject projected on the sensor unit 704 is condensed at a position that is outside the ideal condensing optical path 703 from the center to the outside, so that the image is distorted into a barrel shape. Such image distortion is called barrel distortion.

  In the configuration shown in FIG. 7B, the rear lens 705 is a concave lens. Such a configuration is often designed for the purpose of reducing and projecting an optical image of a subject imaged at a wide angle onto the sensor unit 708 as it is. In the configuration of FIG. 7B, the light incident on the rear lens 705 is the same as the principle of FIG. 7A, and the light traveling around the rear lens 705 deviates from the ideal condensing light path 707 due to coma aberration. , Along the inner optical path 706 with respect to the lens center. Accordingly, since the optical image of the subject projected on the sensor unit 708 is condensed at a position deviating inward from the ideal condensing light path 707 from the center to the outer side, the image is distorted into a pincushion type. Such image distortion is called pincushion distortion.

  Note that most of the lenses designed for imaging wide-angle images are composed of convex lenses as shown in FIG.

  FIG. 8 is a diagram for explaining a specific influence caused by distortion. When a subject 801 (square square) shown in FIG. 8A is imaged through a concave lens, pincushion distortion is generated as shown in an image 802. Further, when the subject 801 is imaged through a convex lens, barrel distortion occurs as shown in an image 803. As described above, when an imaging system including a lens that generates distortion is put into practical use, the captured image is distorted, and thus practicality is impaired.

  FIG. 8B shows an image photographed by an in-vehicle rear photographing system that can photograph the rear of the automobile when the automobile moves backward. As shown in FIG. 8B, when barrel distortion occurs in the imaging device mounted on the rear part of the automobile, the subject is distorted near the periphery of the captured image, and it is difficult to obtain a sense of perspective. Will occur.

  A conventional method for improving such distortion will be described.

  FIG. 9 shows a configuration in which a plurality of lenses are combined to improve distortion. First, the configuration shown in FIG. 9A is a configuration in which a lens 901 of the same type as the rear lens 903 configured by a convex lens is disposed on the subject side (upper side in the drawing) of the rear lens 903 via the diaphragm 902. It is. In this configuration, the coma aberration of the rear lens 903 is canceled by the lens 901 so that the optical path 904 of the light incident on the sensor unit 905 is substantially matched with the ideal condensing optical path, thereby suppressing image distortion.

  Although not shown, if the lens itself is called an “aspheric lens” and has different curvatures at the lens center and the lens periphery, coma and distortion can be improved.

  Further, as shown in FIG. 9B, the lens 906 and the rear lens 908 are constituted by concave lenses, and the concave portions of both lenses are arranged opposite each other with the diaphragm 907 interposed therebetween, so that the sensor unit 910 The optical path 909 of the incident light can be made substantially coincident with the ideal condensing optical path, and distortion of the image can be suppressed.

There has also been proposed a method for correcting an image in which distortion has occurred by calculation. This is a method of obtaining a correct corrected image by correctly grasping the distortion aberration amount itself, holding it as a coefficient, and developing it in a correction calculation, as disclosed in Patent Documents 1 and 2 and the like.
JP 2000-004391 A JP 09-294225 A

  However, in the case of the configuration shown in FIG. 9, the lens 901 (or 906) of the same type as the rear lens 903 (or 906) is required, and there is a problem that the entire imaging apparatus is increased in size.

  Further, as disclosed in Patent Documents 1 and 2, the method for correcting distortion by signal processing requires an integrated circuit for correction calculation (LSI) or DSP (digital signal processing LSI), and the entire camera system. There is a problem that the power consumption increases and the cost increases.

  SUMMARY OF THE INVENTION In view of the above problems, an object of the present invention is to provide a solid-state imaging device and an imaging system that can suppress image distortion and can be realized with a small size, low cost, and low power consumption.

  In order to achieve the above object, a first configuration of the solid-state imaging device according to the present invention includes a light receiving unit that is formed in a semiconductor substrate and accumulates luminance information corresponding to the amount of incident light received, and the light receiving unit is two-dimensional. A plurality of imaging units arranged in a shape, and the light receiving unit is arranged by changing the arrangement interval from the center of the imaging unit toward the outer periphery.

  According to a second configuration of the solid-state imaging device of the present invention, a plurality of light receiving units that are formed in a semiconductor substrate and store luminance information corresponding to the amount of incident light received and a plurality of the light receiving units are arranged in a two-dimensional manner. An imaging unit and a control unit that controls to read a signal from the light receiving unit, and the control unit is configured such that an interval between signals selectively read from the light receiving unit is from the center of the imaging unit toward an outer peripheral direction. Read control is performed so as to change.

  In the solid-state imaging device and the imaging system according to the present invention, it is possible to effectively suppress distortion during imaging while simultaneously achieving a reduction in camera thickness, power consumption, and price.

  In the first configuration of the solid-state imaging device of the present invention, the arrangement interval of the light receiving units may be changed so that the center of the imaging unit is dense and sparse toward the outer peripheral direction of the imaging unit. Good.

  Further, the arrangement interval of the light receiving units may be changed so that the center of the imaging unit is sparse and becomes dense toward the outer peripheral direction of the imaging unit.

  The second configuration of the solid-state imaging device according to the present invention is such that the interval at which the signal is read from the light receiving unit is changed so that the center of the imaging unit is dense and sparse toward the outer peripheral direction of the imaging unit. It is good also as composition which has.

  Further, the interval of reading out signals from the light receiving unit may be changed so that the center of the imaging unit is sparse and becomes dense toward the outer peripheral direction of the imaging unit.

  In addition, a control terminal for adjusting an interval for reading a signal from the light receiving unit may be further provided, and the interval of the signal read from the light receiving unit may be changed according to a control signal input to the control terminal.

  The interval between the arrangements of the light receiving parts is that the central part is densely arranged in the imaging part, and the central part is sparsely arranged oppositely to the outer periphery of the imaging part. The case where it becomes dense toward the outer periphery of an imaging part can be considered. This relationship is assumed to be optimized according to the characteristics of the lens, and the degree of density, the ratio of the outermost peripheral distance to the central distance, and the interval change specification from the center to the outermost periphery (for example, linearity or There is no particular limitation on the logarithm).

(Embodiment 1)
FIG. 1 is a diagram for explaining an example of a solid-state imaging device according to Embodiment 1. FIG. 1 (a) shows a subject 5 composed of a square grid. FIG. 1B is a plan view of the imaging unit 3 in a state where an optical image 5a of the subject is projected. In the first embodiment, as shown in FIG. 7 (a), the condensing is performed by the rear lens formed of a convex lens, so that it is projected onto the imaging unit 3 as shown in FIG. 1 (b). Barrel distortion occurs in the optical image 5a of the subject. FIG. 1C shows an image captured by the imaging unit 3.

  In FIG. 1, the imaging unit 3 includes a light receiving unit 1 and an invalid area 2. The light receiving unit 1 is an area that converts the light that has reached the imaging unit 3 into electric charge, accumulates it, and outputs it as an electrical signal. The invalid area 2 is an area that does not react to the luminance information of the light that has reached the imaging unit 3. In the first embodiment, the interval between the light receiving unit 1 and the invalid area 2 is arranged so as to gradually differ from the center of the imaging unit 3 toward the outside. Specifically, in the vicinity of the center of the imaging unit 3, the invalid area 2 is small and the light receiving units 1 are densely arranged. Further, as the distance from the center of the imaging unit 3 toward the outer periphery is increased, the intervals between the light receiving units 1 become sparse, and the invalid area 2 is increased.

  In addition, as a specific example of the interval between the light receiving unit 1 and the invalid region 2, for example, when a convex lens having a distortion rate (a deviation rate between an image in which distortion is generated and a subject image) of 20% is mounted, In the outermost periphery of the imaging unit 3, the light receiving unit 1 and the invalid region 2 are arranged so that the invalid region 2 is 20% of the size of the light receiving unit 1. Further, between the center of the imaging unit 3 and the outermost periphery, the light receiving unit 1 and the invalid region 2 are arranged so that the ratio of the invalid region 2 to the size of the light receiving unit 1 changes linearly. That is, the size of the invalid area 2 is varied so that the ratio of the invalid area 2 gradually decreases from the outermost periphery of the imaging unit 3 (the ratio of the invalid area 2 is 20%) toward the center.

  When the barrel-distorted optical image 5 a is incident on the imaging unit 3 configured as illustrated in FIG. 1B, the light receiving unit 1 receives and photoelectrically converts the image, and an electrical signal is output from the imaging unit 3. . The electrical signal output from the imaging unit 3 is input to a separately provided image signal processing circuit, and image information is generated. Here, as shown in FIG. 1B, the light receiving unit 1 is arranged, so that image information 6 with reduced distortion is obtained from the image signal processing circuit as shown in FIG. 1C. It is done.

  As described above, according to the present embodiment, the light receiving units 1 in the imaging unit 3 are densely arranged at the center of the imaging unit 3 and are arranged sparsely toward the outer periphery of the imaging unit 3. , Barrel distortion can be reduced.

  In addition, about the space | interval of the light-receiving part 1, the ratio of the light-receiving part 1 and the invalid area | region 2 in the outermost periphery of the imaging part 3 and the ratio of the light-receiving part 1 and the invalid area 2 in the middle from the center of the imaging part 3 to the outermost periphery The changing method is not limited to the above.

(Embodiment 2)
As described above, in the first embodiment, the ineffective area 2 is small in the vicinity of the center of the imaging unit 3, that is, the light receiving units 1 are densely arranged, and the light receiving units 1 become sparse as they move from the center of the imaging unit 3 toward the outer periphery. The invalid area 2 is arranged so as to increase. In the second embodiment, there are many invalid areas in the vicinity of the center of the imaging unit, that is, the light receiving units are sparsely arranged, and as the distance from the center of the imaging unit to the outer periphery increases, the interval between the light receiving units decreases and the invalid area decreases. Are arranged as follows. In addition, about the structure of the imaging part of Embodiment 2, illustration is abbreviate | omitted for convenience.

  By adopting such a configuration, the pincushion distortion (see the image 803 in FIG. 8A) that occurs when the concave lens 705 is mounted as shown in FIG. 7B can be reduced. it can.

  In addition, about the space | interval of the light-receiving part 1, the ratio of the light-receiving part 1 and the invalid area | region 2 in the outermost periphery of the imaging part 3, the light-receiving part 1 and the invalid area 2 in the middle of the outermost periphery of the imaging part 3 from the center of the imaging part 3 About how to change the ratio. It is not limited to the above.

(Embodiment 3)
FIG. 2 is a diagram illustrating an example of the solid-state imaging device according to the third embodiment. FIG. 2A shows a subject composed of a square grid. FIG. 2B is a plan view of the imaging unit in a state where an optical image of the subject is projected. In the third embodiment, since a rear lens composed of a convex lens is mounted as shown in FIG. 7A, the subject projected on the imaging unit 13 as shown in FIG. In the optical image 15a, barrel distortion occurs. FIG. 2C shows an image captured by the imaging unit 13.

  In FIG. 2, the imaging unit 13 includes a light receiving unit 11 and an invalid area 12. The light receiving unit 1 is an area that converts the light that has reached the imaging unit 3 into electric charge, accumulates it, and outputs it as an electrical signal. The invalid area 12 is an area that does not react to the luminance information of the light that has reached the imaging unit 13. In the third embodiment, a block configured only by the light receiving unit 11, a block configured only by the invalid region 12, and a block including the light receiving unit 11 and the invalid region 12 at a predetermined ratio are arranged. ing. Specifically, in the vicinity of the center of the imaging unit 13, a block including a large number of light receiving units 11 (that is, a small number of invalid areas 12) is arranged. In addition, the light receiving units 11 are arranged sparsely from the center of the imaging unit 13 toward the outer periphery, and blocks in which the proportion of blocks in the invalid area 12 is gradually increased are arranged.

  As a specific example of the interval between the light receiving unit 11 and the ineffective region 12, for example, when a convex lens having a distortion rate (a deviation rate from the subject image of the image after distortion) of 20% is mounted, first, the imaging unit 13 Is divided into 200 in both the horizontal direction and the vertical direction to form a block, a block including 100% of the light receiving unit 11 is arranged at the center of the imaging unit 13, and the light receiving unit 11 is arranged at the outermost periphery of the imaging unit 13. A block including 80% and 20% of the invalid area 12 is arranged. In the block between the center of the imaging unit 3 and the outermost periphery, the ratio between the light receiving unit 11 and the invalid area 12 in each block is linearly changed according to the distance from the center of the imaging unit 3. The ratio of the invalid area 13 in the block is changed. Note that the “block” means a unit in which a plurality of light receiving units are grouped, and a photoelectric conversion operation and an output of an electric signal are performed for each light receiving unit.

  When the barrel-distorted optical image 15 a is incident on the imaging unit 13 configured as illustrated in FIG. 2B, the light receiving unit 11 receives and photoelectrically converts the image, and an electrical signal is output from the imaging unit 13. . The electrical signal output from the imaging unit 13 is input to a separately provided image signal processing circuit, and image information is generated. Here, since the light receiving section 11 is arranged as shown in FIG. 2B, the image information 16 with reduced distortion as shown in FIG. 2C is obtained from the image signal processing circuit. It is done.

  As described above, according to the present embodiment, the light receiving units 11 in the imaging unit 13 are densely arranged at the center of the imaging unit 13 and are arranged sparsely toward the outer periphery of the imaging unit 13. , Barrel distortion can be reduced.

  Further, the difference between the second embodiment and the first embodiment is a difference between changing in units of size of the light receiving unit 1 or changing in units of block size obtained by dividing the imaging unit 13 as a block. As an effect of the second embodiment, it is possible to suppress a decrease in resolution near the outer periphery of the imaging unit 13.

  The interval between the light receiving unit 11 and the invalid area 12 in each block, or the ratio between the light receiving unit 11 and the invalid area 12 in each block at the outermost periphery of the imaging unit 13, from the center of the imaging unit 13 to the outermost periphery. The ratio changing method in the middle is not limited to the above.

(Embodiment 4)
In the above-described third embodiment, the number of blocks of the invalid region 12 is small in the vicinity of the center of the imaging unit 13, that is, the blocks of the light receiving unit 11 are densely arranged, and the light receiving unit 11 extends from the center of the imaging unit 13 toward the outer periphery. The blocks are arranged sparsely and the blocks in the invalid area 12 are increased.

  In the fourth embodiment, the number of blocks in the invalid area 12 is increased in the vicinity of the center of the imaging unit 13, that is, the intervals of the blocks of the light receiving unit 11 are sparsely arranged. The blocks are closely spaced so that the number of blocks in the invalid area 12 is reduced. Note that the “block” means a unit in which a plurality of light receiving units are grouped, and a photoelectric conversion operation and an output of an electric signal are performed for each light receiving unit. Although illustration and detailed description are omitted, in this configuration, pincushion distortion can be reduced.

  In addition, about the space | interval of the block of the light-receiving part 11, the ratio of the block of the light-receiving part 11 and the invalid area | region 12 in the outermost periphery of the imaging part 13 and the light reception in the middle from the center of the imaging part 13 to the outermost periphery of the imaging part 13 The ratio changing method between the block of the part 11 and the block of the invalid area 12 is the same without limitation.

(Embodiment 5)
FIG. 3 is a diagram illustrating an example of a solid-state imaging device according to the fifth embodiment. FIG. 3A shows a subject composed of a square grid. FIG. 3B is a plan view of the imaging unit in a state where an optical image of the subject is projected. In the fifth embodiment, since a rear lens composed of a convex lens is mounted as shown in FIG. 7A, the subject projected on the imaging unit 33 as shown in FIG. In the optical image 35a, barrel distortion is generated. FIG. 3C shows an image captured by the imaging unit 33.

  In FIG. 3, the light receiving units 31 and 32 are arranged in a matrix in the imaging unit 33. The light receiving unit 31 is an area that converts the light that has reached the imaging unit 33 into electric charge, accumulates it, and outputs it as an electrical signal. The light receiving unit 32 has the same structure as the light receiving unit 31 in terms of structure, but is an area that does not output an electrical signal. In the fifth embodiment, the interval between the light receiving unit 31 and the light receiving unit 32 is changed. Specifically, in the vicinity of the center of the imaging unit 33, the intervals between the light receiving units 31 are closely arranged in the vertical or horizontal direction. Further, as the distance from the center of the imaging unit 33 toward the outer periphery, the intervals between the light receiving units 31 are sparsely arranged, and the light receiving units 32 are increased.

  For example, when a convex lens with a distortion rate (deviation rate of the image after distortion aberration of the subject image) of 20% is mounted, first, when the imaging unit 33 is divided into 200 parts in both the horizontal and vertical directions, a block is formed. At the center of the image capturing unit 33, a block including 100% of the light receiving unit 31 is disposed, and at the outermost periphery of the image capturing unit 33, a block including 80% of the light receiving unit 31 and 20% of the light receiving unit 32 is disposed. Further, in the block between the center of the imaging unit 33 and the outermost periphery, the ratio between the light receiving unit 31 and the light receiving unit 32 in each block is linearly changed in accordance with the distance from the center of the imaging unit 33. The ratio of the light receiving unit 32 in the block is changed. Note that the “block” means a unit in which a plurality of light receiving units are grouped, and a photoelectric conversion operation and an output of an electric signal are performed for each light receiving unit.

  The actual image information obtained by such a configuration is a collection of only the electrical signals that have been photoelectrically converted by the light receiving unit 31 and output as shown in the image information 36 shown in FIG. Aberration is reduced.

  As described above, according to the present embodiment, the imaging unit includes the light receiving unit 31 that performs photoelectric conversion and outputs an electrical signal, and the light receiving unit 32 that has the same configuration as the light receiving unit 31 but does not perform photoelectric conversion. In the vicinity of the center of 33, the light receiving portions 31 are densely arranged, and the light receiving portions 31 are sparsely arranged toward the outer periphery of the imaging portion 33, so that image information 36 with reduced barrel distortion can be obtained. it can.

  In addition, about the space | interval and change rate of the light-receiving part 31 and the light-receiving part 32, it is the same as that of the above-mentioned Embodiment 1-4, and is not specifically limited.

(Embodiment 6)
The sixth embodiment is a configuration for controlling the interval between the light receiving unit 31 and the light receiving unit 32 described in the fifth embodiment.

  FIG. 4 is a circuit diagram showing a configuration for controlling the operation of the light receiving unit. The configuration of the solid-state imaging device in this embodiment is an example of an XY address type MOS solid-state imaging device. In FIG. 4, the light receiving unit 40 includes a photodiode 41 that performs photoelectric conversion, a vertical control line 42 to which a control signal for performing row selection (Y address) of the photodiode 41 is input, and an electrical output from the photodiode 41. It consists of a vertical signal line 43 for transmitting a signal (hereinafter referred to as a pixel signal).

  Further, in order to drive the light receiving unit 40, a horizontal signal selection switch 44, an OR circuit 45, an inverting circuit 46, a horizontal shift register 47, a vertical shift register 48, a drive pulse input terminal 49, a vertical output interval control terminal 50, a logic A sum circuit 51, an inverting circuit 52, an output amplifier 53, an output terminal 54, a horizontal output interval control terminal 55, and a drive pulse input terminal 56 are provided. That is, the vertical shift register 48 that drives the light receiving unit 40 based on the drive pulse input from the drive pulse input terminal 49 and the horizontal signal that controls the signal on the vertical signal line 43 by turning on / off the horizontal signal selection switch 44. And a shift register 47, and an output amplifier 53 for finally outputting the signal obtained from the horizontal signal selection switch 44. In the conventional solid-state imaging device, the drive pulses are input to the drive pulse input terminal 49 and the drive pulse input terminal 56, respectively, so that all the signals of all the light receiving units 40 are output. Is characterized in that the light receiving unit 40 is selectively operated based on a control signal input via the vertical output interval control terminal 50 and the horizontal output interval control terminal 55.

  First, the role of the vertical output interval control terminal 50 will be described.

  The vertical output interval control terminal 50 is connected to an OR circuit 51 that performs an OR operation with the output signal from the vertical shift register 48, and the output signal of the OR circuit 51 is transmitted to the light receiving unit 40. . Normally, if a high voltage is input to the vertical output interval control terminal 50, an output signal of the vertical shift register 48 is input to the light receiving unit 40 via the vertical control line 42, and a pixel signal is output from the vertical signal line 43. The On the other hand, when a low voltage is input to the vertical output interval control terminal 50, the output signal of the vertical shift register 48 is not transmitted to the light receiving unit 40. That is, by inputting a low voltage to the vertical output interval control terminal 50, it is possible to create a row in which no pixel signal is output.

  An inverting circuit 52 is connected to the output terminal of the OR circuit 51. Therefore, when the input to the light receiving unit 40 is a low voltage, a high voltage is output from the inverting circuit 52, and this output is returned to the vertical shift register 48. When the high voltage output from the inverting circuit 52 is input, the vertical shift register 48 forcibly shifts the control target to the next row. In general, when a Low voltage is input to the vertical output interval control terminal 50, the corresponding row is regarded as a row that does not exist at all, and moves to the next row.

  Similarly, in the combination of the horizontal output interval control terminal 55, the OR circuit 45, and the inverting circuit 46, the same operation is realized in the horizontal direction.

  FIG. 5 shows the drive timing of the solid-state imaging device in the present embodiment.

  FIG. 5A shows a vertical shift register drive pulse input to the drive pulse input terminal 49. FIG. 5B shows a vertical output interval control pulse input to the vertical output interval control terminal 50. FIG. 5C shows a horizontal shift register drive pulse input to the drive pulse input terminal 56. FIG. 5D shows a horizontal output interval control pulse input to the horizontal output interval control terminal 55. FIG. 5E shows a signal output from the output terminal 54.

  First, as shown in FIG. 5A, the vertical shift register 48 is driven by a vertical shift register drive pulse input every vertical period, and outputs a High signal to the input terminal of the OR circuit 51 at the same timing. ing. Further, the vertical output interval control pulse shown in FIG. 5B is input to the vertical output interval control terminal 50, and the vertical output interval control pulse is input to one input terminal of the OR circuit 51. Therefore, the OR circuit 51 outputs a High signal to the vertical control line 42 at the timing shown in FIG. In the present embodiment, the vertical output interval control pulse is High during periods V1, V4, V6,. Although not shown, the vertical output interval control pulse is a pulse having a short period in the middle of the period and a longer period toward the front side and the rear side of the period within the period of one image.

  The horizontal shift register 47 is driven by a horizontal shift register drive pulse input every horizontal period as shown in FIG. 5C, and outputs a High signal to the input terminal of the OR circuit 45 at the same timing. ing. Further, the horizontal output interval control pulse shown in FIG. 5D is input to the horizontal output interval control terminal 50, and the horizontal output interval control pulse is input to one input terminal of the OR circuit 45. Therefore, the logical sum circuit 45 controls the switch 44 to be turned on at the timing shown in FIG. In the present embodiment, the horizontal output interval control pulse is a pulse having a short period in the middle of each vertical period and a longer period toward the front side and the rear side of the period within each vertical period.

  As shown in FIG. 5B, in the period in which the vertical output interval control pulse is High, only in the period in which the horizontal output interval control pulse is High as shown in FIG. Thus, a signal is output from the output terminal 54. At this time, a signal for one image is accumulated by the output amplifier 53, and a signal having a constant cycle is output for each vertical period. In the present embodiment, a signal having a timing synchronized with the horizontal output interval control pulse is output from the output terminal 54 in each of the periods V1, V4, V6,.

  In FIG. 5, in order to simplify the operation principle, the vertical shift register drive pulse and the horizontal shift register drive pulse are shown in such a manner that the number of rows and the number of columns are all input. The number of columns, that is, the number of vertical output interval control pulses shown in FIG. 5B and the number of horizontal output interval control pulses shown in FIG.

  In this way, the output interval control terminal 50 is provided and externally controlled to receive a light receiving unit (light receiving unit 31 in FIG. 3) at an arbitrary interval, and a light receiving unit that does not output a pixel signal (light receiving in FIG. 3). The operation of the unit 32) can be selectively controlled.

  In this embodiment, the horizontal scanning and the vertical scanning are of the shift register type, but a decoder type as shown in FIG. 6 can be similarly realized. In the case of the decoder type as shown in FIG. 6, the timing generation circuit 63 is prepared in advance with several patterns in which the output interval table of the light receiving unit 31 and the light receiving unit 32 shown in FIG. The table is selected or the pattern is switched based on the control signal input to the output interval control terminal 61. Based on the timing signal output from the timing generation circuit 63, the vertical decoder 64 outputs a predetermined pulse (see FIG. 5B) to each vertical control line 42 to operate the light receiving unit 40. Further, the horizontal decoder 65 controls the switch 44 to be turned on / off based on the timing signal output from the timing generation circuit 63. For example, control is performed so that the switch 44 is turned on during the High period in the pulse shown in FIG.

  In addition, as shown in FIGS. 4 and 6, an example of controlling the output interval has been taken, but the circuit configuration and the implementation method designed based on the same concept are not particularly limited to the illustrated configuration. Absent.

  If the solid-state imaging device of the present invention is a solid-state imaging device having a light-receiving unit that accumulates luminance information and an imaging unit in which a plurality of light-receiving units are arranged two-dimensionally, the circuit format of each pixel and drive circuit It is not limited. For example, the active type in which the output circuit in the pixel is an amplifier circuit provided with an amplifier and the passive type solid-state imaging device in which the output circuit in the pixel is not provided with an amplifier are charged with a CCD type (Charge Coupled Device: Charge-coupled device) A solid-state imaging device may be used.

  As described above, the solid-state imaging device and the imaging system according to the present invention are effectively distorted without increasing the size, increasing the cost, and increasing the power consumption due to the conventional improvement method (increase in symmetrical lens, correction by signal processing). It is possible to improve the aberration. Therefore, the present invention can be used in all fields where a camera is required to be small and thin and distortion is an obstacle to using image information.

  For example, the present invention can also be used for an in-vehicle rear-view camera, an in-vehicle monitoring camera, a camera as an alternative to an in-vehicle rearview mirror, a mobile phone camera, and the like. It is also effective for wide-angle imaging cameras used for artificial satellites.

1 is a plan view of a solid-state imaging device according to Embodiments 1 and 2 of the present invention. Plan view of a solid-state imaging device according to Embodiments 3 and 4 of the present invention Plan view of a solid-state imaging device according to Embodiment 5 of the present invention Circuit diagram of solid-state imaging device according to Embodiment 6 of the present invention Timing chart showing operation of solid-state imaging device according to Embodiment 6 of the present invention The block diagram which concerns on another realization method of Embodiment 6 of this invention. Schematic diagram for explaining distortion Schematic diagram showing the effect of distortion Schematic diagram showing an example of conventional distortion countermeasures

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Light-receiving part 2 Invalid area 3 Image pick-up part 40 Light-receiving part 41 Photodiode 42 Vertical control line 43 Vertical signal line 44 Switch 45, 51 OR circuit 46, 52 Inversion circuit 47 Horizontal shift register 48 Vertical shift register 49, 56 Drive pulse input Terminal 50 Vertical output interval control terminal 53 Output amplifier 55 Horizontal output interval control terminal

Claims (8)

A light receiving portion that is formed in the semiconductor substrate and accumulates luminance information according to the amount of incident light received;
An imaging unit having a plurality of the light receiving units arranged two-dimensionally,
The solid-state imaging device, wherein the light receiving unit is arranged by changing an arrangement interval from a center of the imaging unit toward an outer periphery. A light receiving portion that is formed in the semiconductor substrate and accumulates luminance information according to the amount of incident light received;
An imaging unit in which a plurality of the light receiving units are arranged two-dimensionally;
A control unit that controls to read a signal from the light receiving unit,
The controller is
A solid-state imaging device, wherein readout control is performed so that an interval of signals selectively read from the light receiving unit changes from a center of the imaging unit toward an outer peripheral direction. The arrangement interval of the light receiving parts is
The solid-state imaging device according to claim 1, wherein the center of the imaging unit is dense and is changed so as to become sparse toward the outer peripheral direction of the imaging unit. The arrangement interval of the light receiving parts is
The solid-state imaging device according to claim 1, wherein a center of the imaging unit is sparse, and the imaging unit is changed so as to become dense toward an outer peripheral direction of the imaging unit.   3. The solid-state imaging device according to claim 2, wherein an interval of reading as a signal from the light receiving unit is changed so that a center of the imaging unit is dense and sparse toward an outer peripheral direction of the imaging unit.   3. The solid-state imaging device according to claim 2, wherein an interval of reading from the light receiving unit as a signal is changed so that a center of the imaging unit is sparse and becomes dense toward an outer peripheral direction of the imaging unit. A control terminal for adjusting an interval for reading a signal from the light receiving unit;
The solid-state imaging device according to claim 2, wherein an interval of signals read from the light receiving unit is changed in accordance with a control signal input to the control terminal.   An imaging system comprising the solid-state imaging device according to claim 1.

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