JP4704942B2 - Solid-state imaging device and imaging method - Google Patents

Description

  The present invention relates to a solid-state imaging device and an imaging method, and in particular, the solid-state imaging device relates to a horizontal transfer and output amplifier of a CCD (Charge Coupled Device) type imaging device that converts incident light into an image signal. Relates to a horizontal transfer method.

  Patent Document 1 discloses that one transfer path, that is, a shift register is branched, and an amplifier is provided at each end of the branched transfer path. The amplifier is a floating diffusion amplifier (FDA), and each has different charge detection sensitivity or charge / voltage conversion efficiency. When the subject has low brightness, the output signal is output from a highly efficient amplifier. Thus, the voltage conversion efficiency with respect to the low signal charge obtained by light reception is increased, and the sensitivity is improved. Further, when the subject has high luminance, an output signal is output from a low efficiency amplifier. When these amplifiers are used, an image generated by the output signal has high sensitivity and a wide dynamic range.

Patent Document 2 also branches one transfer path, that is, a shift register. However, the signal charges obtained by light reception are alternately distributed at the branch portions and transferred to each amplifier. The frequency of the drive pulse supplied to the transfer path before branching is twice the frequency of the drive pulse supplied to the transfer path after branching. Therefore, the transfer path after branching can be driven at half the driving frequency with respect to the driving frequency before branching. Thus, the transfer can be speeded up with the operating frequency of the amplifier kept low.
Japanese Unexamined Patent Publication No. 7-50409 JP-A-5-244340

  Incidentally, Patent Document 1 only describes that the signal charge is guided to one selected transfer path. As in Patent Document 2, it does not disclose that signal charges are output alternately.

  In addition, Patent Documents 1 and 2 do not provide any suggestion or disclosure regarding the order of reading out color signals and how signal charges are distributed to the transfer paths after branching according to colors. Therefore, when signals corresponding to various colors pass through the branching portion alternately, and the branching portion cannot transfer the signal charge completely, mixing of signals between different colors may occur.

  In view of such a problem, an object of the present invention is to provide a solid-state imaging device and an imaging method in which signal mixing does not occur between different colors even when a branching unit cannot completely transfer a signal charge.

  In order to solve the above-described problems, the present invention provides a color filter that separates incident light from an object field into a plurality of colors, and a plurality of filters that are provided corresponding to colors by photoelectrically converting transmitted light from the color filters. A light receiving element, a first transfer means for transferring a signal charge read from the light receiving element in a first direction, and a second transfer for transferring the signal charge transferred by the first transfer means in a second direction. A transfer means, a branch means arranged at the output terminal of the second transfer means and distributing the transferred signal charges to a plurality of output destinations, and a plurality of third transfer means connected to the branch means as output destinations; In the solid-state imaging device including the output unit provided at the output terminal of the third transfer unit, the plurality of colors are divided into a plurality of groups according to the color, and the second transfer unit, the branch unit, and the third transfer The means reads from light receiving elements corresponding to colors belonging to the same group. The out signal charges after transferring, and wherein the transfer of the signal charges read from the light receiving elements corresponding to the colors belonging to different groups.

  According to the present invention, when a second transfer means, for example, a horizontal transfer path is branched halfway and output from a plurality of output units, colors belonging to different groups, for example, R (red), B (blue) signals and , G (green) signal can be completely separated and read out. For example, when a G signal and an RB signal included in the same line or field are transferred, an RB included in the line or field is transferred after the G signal included in the same line or field is transferred. The signal can be transferred. The G signal and the RB signal included in the same line or the same field are read out as if they were signals belonging to different lines or different fields.

  As a result, different colors do not pass through the branching means alternately. For example, charge mixing from the R, B signal to the G signal, or from the G signal to the R, B signal is prevented, and a good image is provided. can do. In the branching means, the reason why signals are likely to be mixed is that the branching means must be able to transfer in a plurality of directions. Therefore, the branching means is larger in size than other transfer units or has a special shape other than a square. This is because it is difficult to transfer the signal charge completely because of its shape. For example, a signal at the end of the branching unit may not be transferred.

  In the present invention, the signal charges that are collectively transferred as being belonging to the same group are not limited to signal charges for one line or one field, but may be more or less than this. A plurality of lines, a plurality of fields, one frame, a plurality of frames, a ½ line, etc. may be transferred at once.

  In the present invention, when the plurality of colors are three colors of red, green, and blue, it is preferable that the group is composed of two groups, a group consisting of red and blue and a group consisting of green. This is because even if signal mixing occurs between red and blue, mixing between red and blue is easy to correct.

  In addition, when there are a plurality of colors belonging to one group, the signal charges read from the light receiving elements corresponding to the plurality of colors are transferred using a plurality of third transfer means and belong to one of the groups. When there is one color, the signal charge read from the light receiving element corresponding to this color can be transferred using a specific one of the third transfer means.

  When there are a plurality of colors belonging to one group, the signal charges read from the light receiving elements corresponding to the plurality of colors are transferred using a plurality of third transfer means and belong to one of the groups. When there is one color, the signal charge read from the light receiving element corresponding to this color can also be transferred using a plurality of third transfer means. At this time, even when there is one color belonging to the group, it can be read out at high speed.

  Further, when there are a plurality of colors belonging to one of the groups, the signal charge read from the light receiving element corresponding to each color is transferred for each color using a specific one of the third transfer means. It is preferable. Since the output means is determined for each color, it is possible to avoid differences in intensity (steps) between the same colors due to individual differences in the characteristics of the output unit.

  Further, when the signal charges are transferred using a plurality of third transfer means, a correction means for correcting the difference in characteristics between the plurality of output means is provided, and the difference in characteristics between the plurality of output means is provided by the correction means. Is preferably corrected. It is possible to correct a color step caused by individual differences in the characteristics of the output unit.

  When performing this correction, a holding unit for holding data for correcting a difference in characteristics between a plurality of output units is provided, and the correcting unit corrects the difference in characteristics by using data held by the holding unit. It is good.

  In order to transfer the signal charges of the colors belonging to the same group to the second transfer means after transferring the signal charges of the colors belonging to the same group, the first transfer means has the second transfer Transferring signal charges read from light receiving elements corresponding to colors belonging to the same group to the means, and then transferring signal charges read from light receiving elements corresponding to colors belonging to different groups Also good.

  In order to solve the above-described problems, the present invention separates incident light from an object field into a plurality of colors by a color filter, and transmits light from the color filter by a plurality of light receiving elements provided corresponding to the colors. The signal charges read from the light receiving element are transferred in the first direction by the first transfer means, and the signal charges transferred by the first transfer means are transferred by the second transfer means by the second transfer means. The signal charges transferred in the direction of 2 are distributed to a plurality of output destinations by branch means arranged at the output end of the second transfer means, and a plurality of third charges connected to the branch means as output destinations. In the imaging method for outputting signal charges via the output means provided at the output terminals of the transfer means and the third transfer means, the plurality of colors are divided into a plurality of groups according to the colors, and the second In the transfer means, branch means and third transfer means The signal charges read from the light receiving elements corresponding to the colors belonging to the same group after transferring, and wherein the transfer of the signal charges read from the light receiving elements corresponding to the colors belonging to different groups.

  The present invention can also be applied to an imaging method that does not use branching means, that is, the incident light from the object field is separated into a plurality of colors by a color filter, and a plurality of light receiving elements provided corresponding to the colors, The transmitted light from the color filter is photoelectrically converted, the signal charge read from the light receiving element is transferred in the first direction by the first transfer means, and the signal charge transferred through the first transfer means is second In the imaging method of transferring in the second direction by the transfer means and outputting the signal charge via the output means provided at the output end of the second transfer means, the plurality of colors are divided into a plurality of groups according to the colors. In the second transfer means, after the signal charges read from the light receiving elements corresponding to the color belonging to the same group are transferred in the second transfer means, they are read from the light receiving elements corresponding to the colors belonging to different groups. Signal charge It may be characterized in that the feed.

  According to the present invention, it is possible to provide a solid-state imaging device and an imaging method in which signal mixing does not occur between different colors even when the branching unit cannot completely transfer the signal charge.

  Next, embodiments of a solid-state imaging device according to the present invention and a solid-state imaging device used in the device will be described in detail with reference to the accompanying drawings. Referring to FIG. 1, in the embodiment of the solid-state imaging device 44 according to the present invention, when signal charges corresponding to a plurality of colors are transferred through the horizontal transfer path 50, When a signal charge corresponding to one color is transferred to the horizontal transfer paths 56 and 58, the converted analog voltage signals 82 and 84 are simultaneously output and the signal charges corresponding to one color are transferred. The analog voltage signal 82 converted from the horizontal transfer path 56 is output.

  In this embodiment, the color filter decomposes incident light into three colors of red, green, and blue. The three colors are divided into two groups, a group consisting of red and blue and a group consisting of green. For the three colors of red, green and blue constituting one line, green and red blue are read out separately, and for the three colors of red, green and blue constituting the next line, green and red blue are read out separately. This is repeated for all lines constituting all pixels (one frame). Therefore, the reading method is progressive reading.

  The signal charge read from the light receiving element corresponding to green is transferred using only the horizontal transfer path 56. The signal charges read from the light receiving elements corresponding to red and blue are transferred using the horizontal transfer paths 56 and 58. The red color is transferred by the horizontal transfer path 56, and the blue color is transferred by the horizontal transfer path 58.

  In this embodiment, the solid-state imaging device of the present invention is applied to a digital camera 10. The illustration and description of parts not directly related to the present invention are omitted. In the following description, the signal is indicated by the reference number of the connecting line in which it appears.

  As shown in FIG. 2, the digital camera 10 includes an optical system 12, an imaging unit 14, an amplifier power supply unit 16, a bias supply unit 18, a driver 20, a preprocessing unit 22, a memory unit 24, a signal processing unit 26, and a system control unit. 28, including a timing signal generator 32;

  The optical system 12 causes the incident light 40 from the object scene to form an image in the imaging unit 14. The imaging unit 14 includes a solid-state imaging device 44 as shown in FIG. Although not shown, the solid-state imaging device 44 is provided with a color filter in the direction in which the incident light 42 arrives so as to correspond to the arrangement position of the light receiving device. The solid-state imaging device 44 has a function of color-separating the incident light 42, converting the separated color component light into a signal charge by the light-receiving element 46, storing it, and outputting it as an electrical signal. The solid-state imaging device 44 reads the accumulated signal charges to the vertical transfer path 48 and sequentially transfers them in the vertical direction. In the solid-state imaging device 44, a horizontal transfer path 50 is formed in a direction orthogonal to the vertical transfer path 48. The signal charge transferred vertically is supplied to the horizontal transfer path 50.

  In the horizontal transfer path 50 of this embodiment, a branching portion 54 is formed at the output end 52. Horizontal transfer paths 56 and 58 are coupled to the branch portion 54, respectively. In the horizontal transfer paths 56 and 58, output amplifiers 60 and 62 are formed at the output ends, respectively. The output amplifiers 60 and 62 are floating diffusion amplifiers. The floating diffusion amplifier has a function of converting a signal charge into an analog voltage signal. Power supply lines 64 and 66 are connected to the output amplifier units 60 and 62. The power supply lines 64 and 66 are connected from the amplifier power supply unit 16 independently of each other. Further, reset signals 68 and 70 are individually supplied from the driver 20 to the output amplifiers 60 and 62. By this supply, the output amplifiers 60 and 62 can be operated independently.

  A bias signal 72 that is a fixed voltage is supplied from the bias supply unit 18 to the branch unit 54. The branching unit 54 branches the signal charge from the horizontal transfer path 50 to one of the horizontal transfer paths 56 and 58 according to the color. The method will be described later.

  A horizontal drive signal 74 is supplied to the horizontal transfer path 50, and a horizontal drive signal 76 is supplied to the horizontal transfer paths 56 and 58. The horizontal drive signal 76 has half the frequency of the horizontal drive signal 74 when transferring signals corresponding to red and blue, and the same frequency as the horizontal drive signal 74 when transferring a signal corresponding to green. . By driving the horizontal transfer paths 56 and 58 in this way, high-speed reading can be performed even if the specification frequency band of the output amplifiers 60 and 62 is half the band of the horizontal drive signal 74. In addition, the solid-state imaging device 44 is supplied with an overflow drain (OFD) pulse 78 and a vertical drive signal 80.

  As described above, the solid-state imaging device 44 outputs the two systems of output signals 82 and 84 from the output amplifiers 60 and 62 to the preprocessing unit 22. The horizontal transfer in the solid-state imaging device 44 will be further described later.

  Returning to FIG. 2, the amplifier power supply unit 16 has a function of supplying power to the output amplifier units 60 and 62 disposed in the solid-state imaging device 44. The amplifier power supply unit 16 supplies power depending on whether the solid-state image pickup device 44 has one or two outputs. This power supply is controlled by a control signal 86 supplied from the signal processing unit 26 to the amplifier power supply unit 16.

  The bias supply unit 18 has a function of supplying a bias signal 72 to the branch unit 54. The bias signal 72 is applied as a bias voltage. The bias supply unit 18 is controlled by a control signal 88 supplied from the signal processing unit 26.

  The driver unit 20 has a function of supplying various drive signals for driving the solid-state image sensor 44. The driver unit 20 is supplied with a plurality of timing signals 90 from the timing signal generator 32. As shown in FIG. 3, the driver unit 20 includes an OFD pulse output unit 92, a vertical (V) driver 94, a horizontal series (HS) driver 96, a horizontal parallel (HP) driver 98, and a reset (RS) driver 100. The OFD pulse output unit 92 outputs the OFD pulse 78 to the solid-state imaging device 44. The V driver 94 outputs a vertical drive signal 80 to the solid-state imaging device 44.

The HS driver 96 outputs a horizontal drive signal 74 to the solid-state image sensor 44. The HP driver 98 outputs a horizontal drive signal 76 to the solid-state image sensor 44. The horizontal drive signal 76 has the same or double period as compared with the period of the horizontal drive signal 74 depending on which color is transferred. In the present embodiment, the period of the horizontal drive signal 76 is constant, and the period of the horizontal drive signal 74 is the same or ½ times the period of the horizontal drive signal 76 depending on the color. The RS driver 100 outputs reset signals 68 and 70 to the solid-state imaging device 44.

  Returning to FIG. 2 again, the preprocessing unit 22 has an analog front end (AFE) function. This function is noise removal by correlated double sampling (CDS) for the supplied analog electrical signals 82 and 84, and digitization of the analog electrical signal from which noise has been removed, that is, A / D conversion. The preprocessing unit 22 is supplied with timing signals or sampling signals 106 and 108 for performing noise removal and A / D conversion on the input signals of each system from the timing signal generator 32. Two analog electrical signals 82 and 84 are supplied to the pre-processing unit 22, but in the case of one input, if only the timing signals 106 and 108 corresponding to the input system are supplied, the CDS In addition, only one system can be operated for A / D conversion. Thereby, power consumption can be reduced. The preprocessing unit 22 outputs one or two systems of digital signals 110 and 112 to the memory unit 24 in response to the supply of the timing signals 106 and 108.

  The memory unit 24 has a function of temporarily storing and outputting the supplied digital signals 110 and 112. Although not shown, the memory unit 24 is provided with a line memory for each system. Input / output of the memory unit 24 is controlled according to a control signal 116 supplied via the bus 114. The memory unit 24 outputs the input digital signals 110 and 108 as digital signals 118 to the signal processing unit 26 via the bus 114 and the signal line 120 in accordance with the control signal 116.

  The signal processing unit 26 has a function of performing signal processing on the supplied digital signal 118 and generating a control signal. The signal processing unit 26 includes a power supply control function unit 122, a bias control function unit 124, an AF control function unit (not shown), an AE control function unit, an AWB (Automatic White Balance) control function unit, an arrangement conversion function unit, and the like. The power supply control function unit 122 has a function of generating a control signal 86 in response to high-speed or low-speed reading. The power control function unit 122 outputs the generated control signal 86 to the amplifier power supply unit 16.

  The bias control function unit 124 outputs a control signal 88 to the bias supply unit 18. The bias supply unit 18 applies the bias signal 72 to the branch unit 54. The AF control function unit has a function of adjusting the focus based on the generated image data. The AE control function unit has a function of obtaining an evaluation value based on the generated image data and adjusting the aperture and shutter speed. The AF control function unit and the AE control function unit send a control signal (not shown) to the system control unit 28 via the signal line 120, the bus 114, and the signal line 134. The AWB control function unit has a function of adjusting white balance based on the generated image data. The layout conversion function unit has a function of correcting image data obtained by reading using two systems or one system, for example, to image data corresponding to the arrangement of the color filter segments of the image, and synthesizing it into a single image. .

  The system control unit 28 generates a control signal 142 for controlling whether the output of horizontal transfer is 2 output / 1 output. The timing signal generator 32 generates various timing signals such as vertical and horizontal synchronization signals, field shift gate signals, vertical and horizontal timing signals, and OFD pulses and reset signals for the solid-state imaging device 44 of the imaging unit 14. It has a function. The timing signal generator 32 generates various timing signals 90, 106 and 108 in response to the control signal 142 from the system control unit 28. The timing signal generator 32 outputs various timing signals 90 to the driver 20. The timing signal generator 32 has a function of generating a reference clock signal, and particularly generates a horizontal timing signal. The timing signal generator 32 divides the horizontal timing signal to generate a horizontal timing signal having two frequencies. The timing signal generator 32 outputs only one or both of the sampling signals 106 and 108 in accordance with the control signal 142 from the system control unit 28. By operating in this way, power consumption of the digital camera 10 can be suppressed.

  Next, the structure of the horizontal transfer path 50, the branching unit 54, the horizontal transfer paths 56 and 58, and the horizontal transfer method of signal charges will be described. The description will be divided into the transfer in the branch unit 54 and one horizontal transfer path 56 and the transfer in the branch unit 54 and one horizontal transfer path 58. In the horizontal transfer paths 50, 56 and 58, a plurality of transfer elements are formed. One transfer element is formed by two electrodes made of polycrystalline silicon (Poly-Silicon) and an impurity layer near the surface of the silicon substrate. The two impurity layers under the two electrodes have different configurations. For this reason, a staircase-like potential potential is formed by applying a drive signal having the same potential to the two electrodes. Hereinafter, one transfer element and two electrodes included in the transfer element are denoted by the same reference numerals. For example, “branch portion 54” indicates a transfer element, and “electrode 54” indicates two electrodes of the branch portion 54.

As shown in FIG. 4, in the horizontal transfer path 50, for example, polysilicon electrodes HS2 and HS1 are formed in this order from the right to the left toward the branch portion 54 (electrode HSL) and using this as a repeating unit. . In the horizontal transfer path 56, six polysilicon electrodes HP1, HP2, HP1, HP2, HP1, and HP2 are formed from the branch portion 54 toward the output amplifier 60. In the horizontal transfer path 58, seven polysilicon electrodes HP2, HP1, HP2, HP1, HP2, HP1, and HP2 are formed from the branch portion 54 toward the output amplifier 62 .

  The output amplifier 60 is formed of an OG (Output Gate) electrode, a floating diffusion (FD), a reset electrode RS, and a reset drain RD arranged from right to left. FIG. 5 shows a cross-sectional structure from the horizontal transfer path 50 to the reset drain RD. FIG. 5 shows from the leftmost reset drain RD to the electrode HP2 of the horizontal transfer path 50. The horizontal transfer path 56 shows only two polysilicon electrodes HP1 and HP2 among the six polysilicon electrodes HP1, HP2, HP1, HP2, HP1, and HP2.

  As shown in this cross section, an impurity layer is formed immediately below each electrode in a P-type silicon substrate (not shown). The impurity layer is doped with an impurity using an ion implantation method or the like, and the potential potential changes depending on the type and concentration of the impurity to be doped. In addition, a predetermined potential potential is formed as will be described later in accordance with the voltage level of the drive signal applied to the electrode formed immediately above the impurity layer.

Next, drive signals supplied to each electrode will be described. Drive signals φHS1 and φHS2 are supplied to the electrodes HS1 and HS2, respectively. A drive signal φHSL is supplied to the electrode HSL. The drive signal φHSL is a constant bias voltage. Drive signals φHP1 and φHP2 are supplied to the electrodes HP1 and HP2. A drive signal φOG is supplied to the electrode OG. The drive signal φOG is a constant bias voltage. The drive signal φRS is supplied to the electrode RS. Further, the drive signal φRD is supplied to the reset drain RD. The drive signal φRD is a constant bias voltage.

  Next, the flow of signal charges that are horizontally transferred using these drive signals will be described, including vertical transfer before horizontal transfer. The signal charge is first generated in the image sensor 44 of the imaging unit 14. The arrangement of pixels in the image sensor 44 is shown in FIG. In the solid-state imaging device 44 in this embodiment, as shown in FIG. 6, the interval between the light receiving elements 46 arranged in the same row direction and the same column direction is set to the same pitch PP, and one light receiving element 46 The light receiving elements 46 adjacent to each other are arranged with a half pitch shift in the row direction and the column direction. This is a so-called honeycomb arrangement. The color filter formed on the incident light side of the light receiving element 46 uses three primary colors RGB, and the color filter segments G are arranged in a square. Focusing on the color segments R and B, they are arranged in a complete RB checkerboard. The filter arrangement as a whole is a so-called G square RB perfect checkered pattern. Since the pixels or the light receiving elements 46 are shifted in this way, the vertical transfer path 48 is formed to meander so as to bypass the pixels.

  The order of transfer on the vertical transfer path 48 is the order of the line 201, the line 202, the line 203, and the line 204. In the line 201, the signal charges are aligned with R, B, R, B,. Yes. In the line 202 and the line 204, signal charges are aligned with G, G, G, G,. In the line 203, signal charges are lined up with B, R, B, R,. This order is also maintained in the horizontal transfer paths 50, 56, and 58. R, B, R, B,... Of the line 201, G, G, G, G,. Horizontal transfer is performed in the order of B, R, B, R,..., G, G, G, G,.

  However, R, B, R, B,... On the line 201 and B, R, B, R,... On the line 203 are transferred by the two horizontal transfer paths 56, 58, and the line 202 And G, G, G, G,... Of the line 204 are transferred by one horizontal transfer path 56. Further, R, B, R, B,... Of the line 201 and B, R, B, R,... Of the line 203 are distributed to the R signal and the B signal by the branching unit 54. The signal is always transferred through the horizontal transfer path 56, and the B signal is always transferred through the horizontal transfer path 58.

  This is shown in FIGS. FIG. 7 shows a state in which R, B, R, B,... Of the line 201 and B, R, B, R,. 2, 3, 4, and 5 are shown. FIG. 8 shows a state in which G, G, G, G,... Of the line 202 and the line 204 transferred next to the line 201 and the line 203 are horizontally transferred in order of time t = 1, 2, It shows about 3, 4, and 5. Times t = 1, 2, 3, 4, and 5 are times when the signal charges are transferred to the left along the horizontal transfer path 50 by one transfer element. At this time, in FIG. 7, the horizontal transfer paths 56 and 58 are driven at half the frequency of the horizontal transfer path 50, so the transfer speed is half. On the other hand, in FIG. 8, since the horizontal transfer paths 56 and 58 are driven at the same frequency as the horizontal transfer path 50, the transfer speed is the same. Details of a method for realizing this will be described later.

  In the signal processing unit following the horizontal transfer path, processing is performed on the assumption that the first line is formed by the signal charges of the line 201 and the line 202 and the second line is formed by the signal charges of the line 203 and the line 204. In the horizontal transfer path 50 shown in FIG. 6, the first line is described as RGBGRGBG..., And the second line is described as BGRGBGRG. This indicates the position on the horizontal transfer path 50 from which the light is transferred, and does not mean that the data is transferred on the horizontal transfer path 50 in the order of RGBGRGBG..., BGRGBGRG.

  Returning to FIG. 6, the signal charges read from the light receiving element 46 to the vertical transfer path 48 are changed from the vertical transfer path 48 to the horizontal transfer path 50 by the 8-phase drive signals φV1 to φV8 supplied to the vertical transfer path 48. Forwarded. As described above, the electrodes HS1, HS2, HS1, HS2,... Are formed on the horizontal transfer path 50 from the left.

  In the horizontal transfer path 50, in the case of the honeycomb arrangement of this embodiment and the G square RB complete checkered pattern, the G signal and the R and B signals are separated as separate lines such as the line 201 and the line 202, and descend. In the general light receiving element array and the color filter array, the G signal and the R and B signals are not necessarily separated separately. In such a case, it is necessary to rearrange the G signal and the R and B signals. For this purpose, for example, a line memory may be provided between the vertical transfer path 48 and the horizontal transfer path 50, rearranged, and then transferred to the horizontal transfer path 50.

  Next, drive signals for the horizontal transfer paths 50, 54, 56, and 58 will be described. First, a case where R, B, R, B,... On the line 201 and B, R, B, R,. FIG. 9 shows drive signals for transferring R, B, R, B,... Focusing on the phase of the drive signal, the drive signal φHS1 in FIG. 9A is a two-phase drive signal that is 180 ° out of phase with the drive signal φHS2 in FIG. 9B. Further, the drive signal φHP1 in FIG. 9C and the drive signal φHP2 in FIG. 9D are in opposite phases and are two-phase drive signals.

  Further, focusing on the period of the drive signal, the drive signals in FIGS. 9A and 9B have a half period of FIGS. 9C and 9D. That is, the frequency of the drive signal in FIGS. 9 (A) and 9 (B) is twice that of FIGS. 9 (C) and 9 (D). As shown in FIG. 9E, the drive signal φRS supplies the level “H” at timings of t = 1, t = 5,... And 4n + 1, for example. The variable n is an integer including zero. Output signals OS1 and OS2 are output as shown in FIG. 9 (F).

  FIGS. 10 and 11 show potentials formed in the horizontal transfer paths 50, 54, 56, and 58 when these drive signals are applied to the horizontal transfer paths 50, 54, 56, and 58, respectively. FIGS. 10 and 11 relate to the structure shown in FIG. 5, and a simplified version of FIG. 5 is also shown in order to show the position of the potential. 10 (a1) and 10 (a2) correspond to time t = 1 in FIG. 7, and FIGS. 10 (b1) and 10 (b2) correspond to time t = 2 in FIG. ), 10 (c2) corresponds to time t = 3 in FIG. 11 (a1) and 11 (a2) correspond to time t = 4 in FIG. 7, and FIGS. 11 (b1) and 11 (b2) correspond to time t = 5 in FIG. 10 (a1), 10 (b1), 10 (c1), 11 (a1), 11 (b1) show horizontal transfer paths 50, 54, 56, and FIG.10 (a2), 10 (b2) , 10 (c2), 11 (a2), and 11 (b2) indicate horizontal transfer paths 50, 54, and 58, respectively. Therefore, the left side of these figures (Figures 10 (a1), 10 (b1), 10 (c1), 11 (a1), 11 (b1)) and the right side (Figures 10 (a2), 10 (b2), 10 As can be seen from the figure, the potentials of (c2), 11 (a2), and 11 (b2)) are the same for the horizontal transfer paths 50 and 54.

  The horizontal transfer will be described with reference to FIGS. Although not shown, when the drive signal φHSL is supplied, immediately below the electrode HSL to which the drive signal φHSL is supplied, as shown in FIGS. A potential barrier (barrier) 148 that prevents the backflow of signal charges supplied from the transfer path 50 is formed.

  The potential formed by changing according to the supplied drive signal and the movement of the signal charge by the constant potentials 146 and 148 will be described. Hereinafter, signal charges corresponding to the colors R, G, and B are referred to as signal charges R, G, and B. First, the transfer of the signal charge R in the horizontal transfer path 56 will be described with reference to FIGS. 10 (a1), 10 (b1), 10 (c1), 11 (a1), and 11 (b1).

  In the present embodiment, the reason why the signal charge can be distributed at the branching portion 54 is as follows. An impurity layer is formed immediately below the electrodes HP2 and HP1 of the horizontal transfer paths 56 and 58 following the branching portion. As a result, when the level “H” is supplied to the electrodes HP2 and HP1, the potential potential of the level that is one step lower than the reference level 146 that is constantly generated in the branching portion 54 by the constant bias voltage and the deepest level are stepped. Formed. This is shown, for example, in FIG. 10 (a2). When the level “L” is supplied to the electrodes HP2 and HP1, a potential that is one level higher than the reference level 146 and the same level as the reference level 146 is formed. This is shown, for example, in FIG. 10 (a1). As a result, as shown below, the level of the potential formed decreases stepwise in the direction toward the signal charge transfer direction. Based on this, the operation will be described in order of time.

At time t = 1, as shown in FIG. 9, drive signals φHS1, φHS2, φHSL, and φHP1 are supplied. The drive signal φHS2 is at level “L”, and the drive signal φHP1 is at level “L”. When the drive signal is applied in this way, the signal charge B is held in the branching unit 54. At this time, the impurity layer below the electrode HP1 of the horizontal transfer path 56 adjacent to the electrode HSL is supplied with the level “L”, for example, a potential potential 148 or a barrier that prevents the signal charge B from being mixed into the horizontal transfer path 56. Is generated.

  A drive signal φHP2 of level “H” is supplied to the electrode HP2 of the horizontal transfer path 58 adjacent to the branching portion. By this supply, a potential potential 152 lower than the reference level is generated as shown in FIG. 10 (a2) so that the signal charge B flows into the horizontal transfer path 58. At this time, the signal charge B exists in both the reference level 146 and the potential potential 152 packets. Every other signal charge R is held in the horizontal transfer path 56 at time t = 1.

  Next, at time t = 2, as shown in FIG. 9B, in the horizontal transfer path 52, the drive signal φHS2 is applied to the electrode HS2 at the level “H”. By this application, a potential potential 148 and a reference level 146 are generated under the electrode HS2. Due to the formation of this potential potential, the electrode HS2 forms a packet with the electrode HSL. A signal charge R is held in this packet. The drive signals at the same level as at time t = 1 are supplied to the electrodes of the horizontal transfer paths 56 and 58, respectively. Therefore, the formed potential potential does not change from time t = 1. During this time, the signal charge B of the electrode HSL moves to the electrode HP2 on the horizontal transfer path 58 side as shown in FIG. 10 (b2).

  Next, at time t = 3, as shown in FIG. 9B, the drive signal φHS2 is applied to the electrode HS2 at the level “L”. By this application, the potential potential becomes a state at time t = 1. The signal charge R held in the packet formed on the electrode HS2 at time t = 2 moves to the reference level 146 of the branching section 54 as shown in FIG. 10 (c1) due to the formation of this potential potential. At this time, the level “H” drive signal φHP1 is supplied to the electrode HP1 of the horizontal transfer path 56 adjacent to the electrode HSL. The potential potential formed under the electrode HP1 becomes a potential potential 152 lower than the reference level 146. As a result, the signal charge R is present in both the reference level 146 and potential potential 152 packets. At this time, the level “L” drive signal φHP2 is supplied to the electrode HP2 of the horizontal transfer path 58. As a result, a potential 148 is generated at the electrode HP2, as shown in FIG. 10 (c2). The potential potential 148 prevents the signal charge R from being mixed into the horizontal transfer path 58. As shown in FIG. 10 (c1), the signal charge R of the branch part 54 moves toward the packet formed on the electrode HP1 of the horizontal transfer path 56.

  As described above, the drive signal φHP2 of the level “L” is applied to the electrode HP2 of the horizontal transfer path 58 adjacent to the electrode HSL. As a result, the potential potential 148 and the reference level 146 are formed under the electrode HP2. A drive signal φHP1 of level “H” is applied to the electrode HP1 adjacent to the electrode HP2. As a result, a level one level lower than the reference level 146 and the deepest potential potential are formed under the electrode HP1. Further, the potential “148” and the reference level 146 are formed by the level “L” supplied to the adjacent electrode HP2. As a result, the signal charge B held in the packet at time t = 2 moves to and is held in the packet formed on the electrode HP1.

  At time t = 2, the signal charges R and B of the electrode HP2 held in the packet formed immediately before the output units 60 and 62 of the horizontal transfer paths 56 and 58 are output to the output side due to this potential potential increase. Moved toward the FD via the electrode OG.

  Next, at time t = 4, the electrode HS2 is supplied with the driving signal φHS2 of level “H”, thereby forming the same potential as at time t = 2. At this time, the signal charge B is held in the formed packet. The signal charge R of the branching part 54 moves to a packet formed immediately below the electrode HP1 of the horizontal transfer path 56. The drive signals having the same level as that at time t = 3 are supplied to the subsequent electrodes of the horizontal transfer paths 56 and 58, respectively. Therefore, the potential formed is the same as at time t = 3.

  Next, at time t = 5, the impurity layer corresponding to the electrode HS2 forms the same potential as at time t = 1. As a result, a potential potential 148 is formed immediately below the electrode HP1 adjacent to the branch portion 54, and becomes a potential barrier against the signal charge B. The signal charge B can be prevented from being mixed or mixed in the horizontal transfer path 56. The branching unit 54 further moves the transferred signal charge B to the horizontal transfer path 58 while forming a packet. The horizontal transfer path 56 is supplied with a drive signal at the same level as that at time t = 1. Therefore, the potential potential formed is the same as at time t = 1. At time t = 5, the signal charges R and B supplied to the FD are converted into analog voltage signals and sent to the output amplifier 60.

  Next, transfer on the horizontal transfer path 58 will be described. In the horizontal transfer path 58, similarly to the horizontal transfer path 56, for example, a P-type silicon substrate (not shown) and an impurity layer are formed immediately below each electrode. This impurity layer is also divided according to the size of the polycrystalline silicon electrode. The separated impurity layer is formed by adjusting the impurity concentration so that a predetermined potential described later is formed according to the voltage level of the supplied drive signal. The horizontal transfer path 58 is characterized in that it is formed by one more than the number of electrodes of the horizontal transfer path 56.

  As shown in FIG. 9, at time t = 1, the level “H” driving signal φHP2, the constant bias voltage driving signal φHSL, and the level “L” driving signal φHP1 are supplied to the electrodes of the horizontal transfer path 58, respectively. . Thus, when each drive signal is applied, the signal charge B is held in the branching portion 54. At this time, the potential potential generated by the impurity layer of the electrode HP2 of the horizontal transfer path 58 adjacent to the electrode HSL is a level 152 that is one step lower than the reference level 146 by the application of the drive signal φHP2. Further, the potential potential 148 formed under the electrode HP1 of the horizontal transfer path 56 functions as a potential barrier and prevents the signal charge B from being mixed.

  Since the drive signal φHP1 of level “L” is supplied to the electrode HP1, the potential potential 148 and the level of the reference level 146 are formed immediately below the electrode HP1. A drive signal φHP2 of level “H” is supplied to the electrode HP2. As a result, a potential potential at a level one step lower than the reference level 146 and at the deepest level is formed immediately below the electrode HP2.

  At time t = 1, since the drive signal is supplied as described above, a packet is formed immediately below each electrode HP2. A signal charge B is held in the packet.

  Next, at time t = 2, as shown in FIG. 9, the drive signal φHS2 of level “H” is applied to the electrode HS2. By this application, the impurity layer under the electrode HS2 generates a potential potential and forms a packet as shown in FIGS. 10 (b1) and (b2). A signal charge R is held in this packet. The drive signals having the same level as that at time t = 1 are supplied to the electrodes of the horizontal transfer path 58 thereafter. Therefore, the potential formed is the same as at time t = 1.

  Next, the potential at time t = 3 is shown in FIG. 10 (c2). At time t = 3, the drive signal φHS2 is applied to the electrode HS2 at the level “L”. By this application, the potential becomes a state at time t = 1. The signal charge R held in the packet immediately below the electrode HS2 at time t = 2 moves to the branching portion 54 that is the reference level 146. At this time, the level “L” drive signal φHP2 is supplied to the electrode HP2 of the horizontal transfer path 58 adjacent to the electrode HSL. The potential potential of the impurity layer under the electrode HP2 becomes a potential potential 148 higher than the reference level 146. That is, a potential barrier is formed. With this formation, the signal charge R does not enter the horizontal transfer path 58. On the other hand, the potential “152” is formed by the level “H” supplied to the electrode HP1 of the horizontal transfer path 56. As a result, the signal charge R moves as indicated by the arrow 162. A packet is formed by the potential potential 152 immediately below the electrode HP1 to which the drive signal φHP1 is supplied in the horizontal transfer path 56, as shown in FIG.

  In the horizontal transfer path 58, a packet is formed below the electrode HP1 at time t = 3 by supplying the level “H” to the drive signal φHP1. The signal charge B is held in the packet of the electrode HP1. The signal charge B of the electrode HP2 held in the packet formed at time t = 2 moves toward the output side due to the increase in potential potential, and is transferred to the FD via the electrode OG.

  Next, at time t = 4, the same potential as at time t = 2 is formed immediately below the electrode HS2. At this time, the signal charge B is held in the formed packet. Subsequent electrodes of the horizontal transfer path 58 are supplied with drive signals at the same level as at time t = 3. Therefore, the potential formed is the same as at time t = 3. The potential potential formed immediately below the electrode HP2 adjacent to the electrode HSL is in a state of a potential potential 148 higher than the reference level 146. Further, the potential potential formed immediately below the electrode HP1 of the horizontal transfer path 56 adjacent to the electrode HSL is in the state of the potential potential 152 lower than the reference level 146.

  Next, at time t = 5, the same potential potential as that at time t = 1 is formed. The signal charge B is held in the packet of the electrode HP2. As described above, the horizontal transfer shown in FIG. 7 is achieved. The horizontal transfer operation will be described with reference to FIGS.

  In the horizontal transfer, for example, signal charges R, B, R, and B supplied from the horizontal transfer path 50 to the branch unit 54 at time t = 1 are distributed to the horizontal transfer paths 56 and 58 by the branch unit 54. In the horizontal transfer paths 50, 56, and 58 of FIG. 7, it can be seen that there is signal charge for each transfer element. The horizontal transfer path 56 transfers only the signal charge R in accordance with the supplied drive signal. Further, the horizontal transfer path 58 transfers only the signal charge B in accordance with the supplied drive signal. At this time, since the potential barrier is formed at the electrode HP1 of the horizontal transfer path 56 adjacent to the branching portion 54, the signal charge B is prevented from being mixed into the horizontal transfer path 56.

  The horizontal transfer path 50 is operated at a frequency twice that of the horizontal transfer paths 56 and 58. As a result, at time t = 2, the horizontal transfer path 50 horizontally transfers the signal charges held in accordance with the supplied drive signal toward the branch unit 54 by one transfer element. On the other hand, in the horizontal transfer path 56, since the level of the supplied drive signal does not change, no signal charge is transferred. Since the level of the drive signal does not change even in the horizontal transfer path 58, no signal charge is transferred. However, the signal charge B of the branch portion 54 moves to the packet formed under the electrode HP2 because the potential potential lower than the reference level 146 of the branch portion 54 is formed under the electrode HP2.

  At time t = 3, the horizontal transfer path 50 performs horizontal transfer for one transfer element with the held signal charge toward the branching unit 54. The signal charge R is held in the packet formed immediately below the branch part 54 and the electrode HP1 of the horizontal transfer path 56 adjacent to the branch part 54. At this time, a potential barrier is formed on the electrode HP2 of the horizontal transfer path 58 adjacent to the branch portion. This prevents the signal charge R from entering the horizontal transfer path 58. Further, the horizontal transfer paths 56 and 58 horizontally transfer the signal charge held in accordance with the level of the supplied drive signal toward the output units 60 and 62 by one transfer element. As a result, the signal charge R and the signal charge B are supplied to the FDs of the output amplifiers 60 and 62 of the horizontal transfer paths 56 and 58, respectively.

  Next, at time t = 4, the horizontal transfer path 50 horizontally transfers the signal charge to be held by one transfer element toward the branching unit 54 in accordance with the supplied drive signal. The signal charge R moves to a packet formed immediately below the electrode HP1 of the horizontal transfer path 56 adjacent to the branch portion 54.

  At time t = 5, the horizontal transfer paths 50, 56 and 58 horizontally transfer the held signal charges by one transfer element toward the output side. Thus, the signal charges of color R and color B are simultaneously converted from the output amplifiers 60 and 62 into analog voltage signals and output as output signals OS1 and OS2. Output signals OS1 and OS2 are processed in parallel. As a result, it is possible to eliminate the difference in signal intensity caused by the time series processing of the output signals OS1 and OS2. Note that if the difference in signal intensity due to time-series processing is acceptable, the output signals OS1 and OS2 may be output alternately.

  By operating in this way, the signal charge can be transferred and output without color mixing. In general, solid-state imaging devices are required to read out the obtained signal charges at high speed as the number of pixels increases. In order to satisfy this requirement, it is necessary to increase the frequency band of the output amplifier of the horizontal transfer path. The solid-state imaging device is difficult to drive at a certain frequency or more, but this is due to, for example, the lack of the frequency band of the output amplifier. However, the solid-state imaging device 44 of the present embodiment has the output units 60 and 62 by branching the output and increasing the number of outputs even if the drive frequency of the horizontal transfer path 50 is increased corresponding to the increase in the number of pixels. Even if the driving frequency is not increased, the signal charge can be read out within a predetermined frequency band. That is, it is possible to improve the reading speed of the signal charge.

  Next, driving signals of horizontal transfer paths 50, 54, 56, and 58 for transferring signal charges in which the same color is aligned with G, G, G, G,. To do. In the case of the same color, in this embodiment, only the horizontal transfer path 56 of the two horizontal transfer paths 56 and 58 is used. At this time, drive signals φHS1 and φHS2 shown in FIGS. 12 (A) and 12 (B) have the same frequency as drive signals φHP1 and φHP2 shown in FIGS. 12 (C) and 12 (D). That is, the drive signals φHS1 and φHS2 are slower than in FIG.

  At time t = 1, the drive signal φHS2 supplied to the final electrode HS2 of the horizontal transfer path 50 is at the level “L”, and the drive signal φHP1 supplied to the electrode HP1 is supplied to the level “H” and the electrode HP2. The driving signal φHP2 is at the level “L”. Therefore, the signal charge is transferred to the electrode HP1, that is, the horizontal transfer path 56 side via the branch portion (HSL) 54.

FIG. 13 shows potentials formed in the horizontal transfer paths 50, 54, 56, and 58 when these drive signals are applied to the horizontal transfer paths 50, 54, 56, and 58. FIG. 13 is for the structure shown in FIG. 5, and a simplified version of FIG. 5 is also shown to indicate the position of the potential. 13 (a1) and 13 (a2) correspond to time t = 1 in FIG. 12, and FIGS. 13 (b1) and 13 (b2) correspond to time t = 2 in FIG. 13 (a1) and 13 (b1) show the horizontal transfer paths 50, 54 and 56, and FIGS. 13 (a2) and 13 (b2) show the horizontal transfer paths 50, 54 and 58.

  At time t = 2, the drive signal φHS2 supplied to the final electrode HS2 of the horizontal transfer path 50 is at the level “H”, and the drive signal φHP1 supplied to the electrode HP1 is supplied to the level “L” and the electrode HP2. The driving signal φHP2 is at the level “H”. Therefore, the signal charge is in the transfer element HS2, and is transferred from the transfer element HP1 to the transfer element HP2.

  Time t = 3 is the same state as time t = 1, and time t = 4 is the same state as time t = 2. The time t = 1 and the time t = 2 are repeated because the drive signals φHS1, φHS2, φHP1, and φHP2 have the same frequency and the phase is adjusted so that only two states occur. .

  For the output section, the reset signal φRS shown in FIG. 12E is applied, and output signals OS1 and OS2 shown in FIGS. 12F and 12G are output. Regarding the transfer of the signal charge G, the solid-state imaging device 44 is a one-line output of only the output signal OS1. Since the output signal OS2 is not used, the power supply of the output amplifier 62 may be turned off. In this case, the power supply of the amplifier power supply unit 16 is controlled by the control signal 86 from the power supply control function unit 122, and the power supply 66 is turned off.

  Only the output amplifier 62 may be operated by reversing the phases of the drive signals φHP1 and φHP2 and the drive signals φHS1 and φHS2. As a result, a one-line output for operating only the horizontal transfer path 58 can be obtained. In this way, in this embodiment, it is possible to easily switch between 1-line readout and 2-line readout and to freely select the output unit.

  By the way, as shown in FIG. 6, when the order of R and B pixels in the first line and the second line is compared, the line 201 in the first line is R, B, R, B, Line 203 is B, R, B, R, and the first pixel of the line is different. If the same horizontal transfer drive signal is used for the first line and the second line, the pixels output from the output unit 60 differ for each line. The same applies to the output unit 62. Since the output unit 60 and the output unit 62 have slightly different characteristics such as gain, a step is generated between the same colors due to the output unit. In order to avoid this, it is preferable to output the same color from the same output unit. A method for realizing this will be described.

  FIGS. 14 (a) and 14 (b) show horizontal drive signals when horizontal transfer is performed on the first and second lines 201 and 203, respectively. First, horizontal transfer of the line 201 will be described with reference to FIG. From the line 201 to the horizontal transfer path 50 via the vertical transfer path, the signal charge is from the head of the line 201, dummy D1, dummy D2, optical black OB1, optical black OB2, R, B, ... Are transferred in this order.

  Drive signals φHS1 and φHS2 shown in FIGS. 14A and 14B are supplied to transfer the signal charges held in the horizontal transfer path 50 to the horizontal transfer paths 56 and 58. The horizontal transfer paths 56 and 58 are supplied with drive signals φHP1 and φHP2 shown in FIGS. 14 (C) and 14 (D). The position where the transfer is started is a position where the potential of the drive signal changes only after the horizontal blanking period 200 has elapsed. At the time of output, the reset signal φRS shown in FIG. 14E is applied immediately before the signal charge enters the output portion, and thereafter, output is performed in the output time region 182.

  The output unit converts the signal charge into an analog voltage signal, and outputs a dummy D2, optical black OB2, R, R,... To each output time region 182 as the output signal OS1 in FIG. . Further, the dummy D1, the optical black OB1, B, B,... Are output to each output time region 182 as the output signal OS2 in FIG. As described above, the output signal OS1 of the horizontal transfer path 56 outputs the color R, and the output signal OS2 of the horizontal transfer path 58 outputs the color B.

  On the other hand, when the line 203 of the second line is transferred horizontally, the output is switched to the line 201 of the first line, so that the drive signal φHS1 shown in FIG. 14 (H) and FIG. Use φHS2 shown. Other signals are the same as those in the first line. Compared to the first line, the start positions of the drive signals φHS1 and φHS2 are earlier in the second line by one cycle of these drive signals.

  As a result, the output unit outputs the dummy D1, the optical black OB1, R, R,... To each output time region 182 as the output signal OS1 in FIG. Further, the output unit outputs the dummy D2, the optical black OB2, B, B,... To each output time region 182 as the output signal OS2 of FIG. Thus, the same color can be output from the same output unit in the first and second lines.

  In this embodiment, the method of shifting the phase of the drive signal φHS is used. However, the method is not limited to this method. There is also a method. 14 shows the case where the drive signals φHS1 and φHS2 are high speed, the same can be done even when the drive signals φHS1 and φHS2 are low speed, and in either case, the output signal can be switched easily. It is.

  In FIG. 8, the signal charge G is transferred using only the horizontal transfer path 56, but the signal charge G may be transferred using the horizontal transfer paths 56 and 58 as shown in FIG. The signal shown in FIG. 9 may be used as the horizontal drive signal at this time. According to this, the signal charge G can also be transferred at high speed. However, in this case, since the same color is output from different output units, there may be a step between the same colors due to the output unit.

  As measures against the step, for example, there are the following methods. Data for correcting a difference in characteristics between a plurality of output units, for example, a gain difference is acquired before the camera 10 is shipped from the factory. As an acquisition method, the camera captures a fixed amount of light, and the output value of the signal charge G of the output units 60 and 62 is measured. Coefficient data for equalizing the output values of the output units 60 and 62 is calculated and stored in the nonvolatile memory in the camera 10. In the correction after shipment, the signal processing unit 26 reads the coefficient data stored in the memory, multiplies the output values of the output units 60 and 62 by the coefficient data, and corrects the gain difference. Thereby, the output of the signal charge G becomes equal.

1 is a block diagram showing a schematic configuration of an embodiment of a two-line readout CCD to which a solid-state imaging device according to the present invention is applied. It is a block diagram which shows the schematic structure of the Example of the digital camera to which the solid-state image sensor of FIG. 1 is applied. FIG. 3 is a block diagram showing a schematic configuration in the driver of FIG. 2. It is the top view which looked at the horizontal transfer path in the solid-state image sensor of FIG. 1 from the top. It is sectional drawing of the principal part of the horizontal transfer path of FIG. It is a figure which shows the pixel shift arrangement | positioning applied to the solid-state image sensor of FIG. 1, and the arrangement pattern of a color filter segment. FIG. 2 is an explanatory diagram illustrating transfer of signal charges R and B in the horizontal transfer path of FIG. 1. FIG. 2 is an explanatory diagram for explaining transfer of a signal charge G in the horizontal transfer path of FIG. 1. 5 is a timing chart showing timings of drive signals supplied to the electrodes of FIG. 4 when transferring signal charges R and B. FIG. It is a figure which shows the potential potential formed in a horizontal transfer path when the drive signal shown in FIG. 9 is applied. It is a figure which shows the potential potential formed in a horizontal transfer path when the drive signal shown in FIG. 9 is applied. 5 is a timing chart showing timings of drive signals supplied to the electrodes of FIG. 4 when transferring signal charges G. FIG. FIG. 13 is a diagram showing a potential potential formed in the horizontal transfer path when the drive signal shown in FIG. 12 is applied. It is a timing chart which shows the drive signal for making the color of the signal charge output from the same output part the same in the 1st line and the 2nd line. It is explanatory drawing explaining transfer of the signal charge G using two horizontal transfer paths.

Explanation of symbols

10 Digital camera
12 Optical system
14 Imaging unit
16 Amplifier power supply
18 Bias supply section
20 drivers
22 Pretreatment section
24 Memory section
26 Signal processor
28 System controller
32 Timing signal generator

Claims (9)

A color filter that separates incident light from the field into a plurality of colors;
A plurality of light receiving elements provided corresponding to the color by photoelectrically converting the transmitted light from the color filter;
First transfer means for transferring a signal charge read from the light receiving element in a first direction;
Second transfer means for transferring the signal charge transferred by the first transfer means in a second direction;
A branching unit arranged at an output end of the second transfer unit and distributing the transferred signal charge to a plurality of output destinations;
A plurality of third transfer means connected as output destinations to the branch means;
In a solid-state imaging device including output means provided at an output end of the third transfer means,
The plurality of colors are divided into a plurality of groups according to the colors,
The second transfer means, the branching means, and the third transfer means correspond to colors belonging to different groups after transferring signal charges read from light receiving elements corresponding to colors belonging to the same group. Transfer the signal charge read from the light receiving element,
When there are a plurality of colors belonging to one of the groups, the signal charges read from the light receiving elements corresponding to the plurality of colors are transferred using a plurality of the third transfer means, and one of the groups When there is one color belonging to the signal charge, the signal charge read from the light receiving element corresponding to the color is transferred using a specific one of the third transfer means. Solid-state imaging device.   2. The solid-state imaging device according to claim 1, wherein the plurality of colors are three colors of red, green, and blue, and the group includes two groups of a group consisting of red and blue and a group consisting of green. A solid-state imaging device.   2. The solid-state imaging device according to claim 1, wherein when there are a plurality of colors belonging to one of the groups, the signal charge read from the light receiving element corresponding to each color is the third transfer unit for each color. A solid-state imaging device that is transferred using a specific one of the two.   The solid-state imaging device according to claim 1, wherein the device includes a correcting unit that corrects a difference in characteristics between the plurality of output units. In the solid-state imaging device according to claim 4, wherein the apparatus includes a holding unit for holding data for correcting a difference in characteristics between the plurality of output means, said correcting means includes data included in said holding means A solid-state imaging device, wherein a difference in characteristics is corrected using   6. The solid-state imaging device according to claim 1, wherein the first transfer unit is read from light receiving elements corresponding to colors belonging to the same group with respect to the second transfer unit. A solid-state imaging device characterized by transferring signal charges read from light receiving elements corresponding to colors belonging to different groups after transferring the signal charges. The incident light from the object scene is separated into multiple colors using a color filter,
A plurality of light receiving elements provided corresponding to the color, photoelectrically convert the light transmitted from the color filter,
The signal charge read from the light receiving element is transferred in the first direction by the first transfer means,
The signal charge transferred by the first transfer means is transferred in the second direction by the second transfer means,
The transferred signal charge is distributed to a plurality of output destinations by branch means arranged at the output end of the second transfer means,
In an imaging method for outputting a signal charge via a plurality of third transfer means connected to the branch means as an output destination and an output means provided at an output end of the third transfer means,
The plurality of colors are divided into a plurality of groups according to the colors,
The second transfer means, the branching means, and the third transfer means correspond to colors belonging to different groups after transferring signal charges read from light receiving elements corresponding to colors belonging to the same group. Transfer the signal charge read from the light receiving element,
When there are a plurality of colors belonging to one of the groups, the signal charges read from the light receiving elements corresponding to the plurality of colors are transferred using a plurality of the third transfer means, and one of the groups In the case where there is one color belonging to the image, the signal charge read from the light receiving element corresponding to the color is transferred using a specific one of the third transfer means. Method.   8. The imaging method according to claim 7, wherein the plurality of colors are three colors of red, green, and blue, and the group includes two groups of a group consisting of red and blue and a group consisting of green. An imaging method.   8. The imaging method according to claim 7, wherein when there are a plurality of colors belonging to one of the groups, the signal charge read from the light receiving element corresponding to each color is output for each color by the third transfer unit. An imaging method characterized by transferring using a specific one of them.