JP4611925B2 - Solid-state imaging device and driving method thereof - Google Patents

Description

  The present invention relates to a solid-state imaging device that branches off a horizontal transfer path of an imaging device halfway and outputs an image signal with two outputs, and a driving method thereof.

  Patent Document 1 describes that one transfer path, that is, a shift register is branched, and an amplifier is provided at each end of the branched transfer path. Each of the amplifiers is a floating diffusion amplifier (FDA), and has different charge detection sensitivity or charge / voltage conversion efficiency. When the subject has low luminance, the output signal is output from a highly efficient amplifier. The selection of the amplifier improves the sensitivity by increasing the voltage conversion efficiency for the low signal charge obtained by light reception. Further, when the subject has high luminance, the output signal is output from a low efficiency amplifier. When this amplifier is used, an image generated by the output signal is an image having a wide dynamic range.

Patent Document 2 also branches one transfer path, that is, a shift register. However, the signal charge obtained by light reception is branched alternately at the branching section and transferred to each amplifier. The frequency of the drive pulse supplied to the transfer path before branching is double the frequency of the drive pulse supplied to the transfer path after branching. In other words, the transfer path drive after branching may be half the drive frequency with respect to the normal drive frequency. Therefore, the amplifier enables the transfer to be performed at a high speed while being within the frequency band possessed as the operating characteristics.
Japanese Unexamined Patent Publication No. 7-50409 JP-A-5-244340

  By the way, Patent Document 1 merely describes guiding to one selected transfer path. Patent Document 2 discloses that signal charges are alternately output. By simply combining these Patent Documents 1 and 2, it is possible to output images corresponding to high sensitivity and a wide dynamic range.

  On the other hand, when generating a color image, a color attribute is assigned to each signal charge. However, Patent Documents 1 and 2 do not provide any suggestion or disclosure about how to transfer and distribute the signal charge to the transfer path after branching for each color. Therefore, it is not possible to provide a noise-reduced image based on the white balance gain related to color.

  Further, in a conventional solid-state imaging device, for example, when a subject having a low color temperature is photographed, the signal charge obtained by each light receiving element in the imaging element is large in the R pixel and small in the B pixel. At this time, if signal charges are horizontally transferred in the order of R pixel, G1 pixel, B pixel, and G2 pixel from the horizontal transfer path before branching, the amount of charge mixed in that the front R pixel leaves behind and enters the rear G1 pixel is This is larger than the charge mixing amount between the front B pixel and the rear G2 pixel. Therefore, even if these G1 pixels and G2 pixels have the same color signal, a difference occurs in the signal amount, which affects the completed image as fixed pattern noise.

  The present invention eliminates the disadvantages of the prior art, and even if an image pickup device having a horizontal transfer path branched in the middle and outputting signal charges to a single or a plurality of signals is used, the influence of transfer deterioration in this branch is eliminated. An object of the present invention is to provide a solid-state imaging device that can be relaxed and obtain a good image, and a driving method thereof.

  According to the present invention, a plurality of light receiving elements arranged in the row and column directions that photoelectrically convert incident light from the object field into signal charges, and arranged corresponding to each of the plurality of light receiving elements, A color filter that separates the incident light into a plurality of colors and enters one of the light receiving elements, a vertical transfer unit that vertically transfers the signal charges read from the plurality of light receiving elements, and the vertical transfer A first horizontal transfer means for receiving the signal charge vertically transferred from the means and horizontally transferring the signal charge; and a plurality of signal charges horizontally transferred to the output terminal of the first horizontal transfer means. Branching means for allocating to any one of the output destinations, second and third horizontal transfer means for receiving the signal charges distributed from the branching means and transferring them horizontally, and the second and third horizontal transfer means Each In the solid-state imaging device using the solid-state imaging device including the first and second output means provided at the force end, the signal charge passes through the second and third horizontal transfer means from the first branching means and the first and second horizontal transfer means. A first drive signal for driving the first horizontal transfer means, including transfer efficiency measurement means for measuring the transfer efficiencies of the second and third horizontal transfer means in the transfer until reaching the second output means; Alternatively, the driving start time of the second drive signal for driving the second and third horizontal transfer means is changed according to the measurement result by the transfer efficiency measurement means, and either one of the second and third horizontal transfer means is selected. This signal charge is transferred by preferentially using.

  The incident light from the object scene is separated into a plurality of colors by a color filter, and the incident light passing through the color filter is photoelectrically converted into a signal charge by a plurality of light receiving elements arranged in the row and column directions. The signal charges read from the plurality of light receiving elements are vertically transferred in the vertical transfer step, and the signal charges vertically transferred from the vertical transfer step are received in the first horizontal transfer step and horizontally transferred. In the branch process arranged at the output end of the first horizontal transfer process, the signal charge horizontally transferred from the first horizontal transfer process is distributed to any of a plurality of output destinations, and is distributed from this branch process. The signal charges are received in the second and third horizontal transfer processes and further transferred horizontally, and the signals are output in the first and second output processes provided at the respective output ends of the second and third horizontal transfer processes. Output a signal according to the charge In the driving method for driving the body image sensor, the second and second signal charges are transferred from the branching process to the first and second output processes through the second and third horizontal transfer processes. Including a transfer efficiency measurement step for measuring the transfer efficiency of each of the three horizontal transfer steps, and a first drive signal for driving the first horizontal transfer step or a second drive for driving the second and third horizontal transfer steps. The drive start time of the drive signal is changed in accordance with the measurement result of the transfer efficiency measurement process, and the signal charge is transferred by preferentially using one of the second and third horizontal transfer processes. To do.

  As described above, according to the solid-state imaging device of the present invention, during high-speed driving, the imaging unit transfers the signal charge obtained from each light receiving element to the first horizontal transfer path via the plurality of vertical transfer paths, and the first When the signal charge horizontally transferred from the horizontal transfer path is branched and transferred to the second and third horizontal transfer paths, the horizontal transfer path of the imaging unit is driven and controlled according to the measurement result by the transfer efficiency measuring unit. By shifting the phase of the horizontal timing signal to be shifted from the initial driving condition, the signal charge transferred to the second horizontal transfer path and the signal charge transferred to the third horizontal transfer path can be reversed. is there.

  Further, according to the solid-state imaging device of the present invention, during high-speed driving, a red one is transferred to a horizontal transfer path with good transfer efficiency among the second and third horizontal transfer paths according to the measurement result by the transfer efficiency measuring unit. Transfer the pixel and blue pixel signal charges and transfer the green pixel to the other horizontal transfer path, reducing the amount of residual charge transferred from the red and blue pixels to the green pixel and obtaining a good image Can do.

  Further, according to the solid-state imaging device of the present invention, during the low-speed driving, all of the second and third horizontal transfer paths that have good transfer efficiency are selected according to the measurement result by the transfer efficiency measurement unit. By transferring this signal charge, it is possible to reduce the amount of residual transfer charge of each pixel, alleviate the influence of transfer deterioration of the entire image, and obtain a good image.

  Further, according to the solid-state imaging device of the present invention, the imaging unit switches the output destinations of the second and third horizontal transfer paths according to the transfer efficiency, so that the output locations of the color signals are the second and third. Even if it changes between horizontal transfer paths, the external circuit of the imaging unit can be configured without changing the connection.

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

  As shown in FIG. 1, the solid-state imaging device 10 of the embodiment is controlled by a system control unit 28, a timing signal generator 32 and a driver 20 by operating an operation unit 30, and incident light from an object scene is Captured by the optical system 12, this field image is captured by the imaging unit 14, the captured image is processed by the preprocessing unit 22, temporarily stored in the memory unit 24, and the image signal stored in the memory unit 24 is also stored. The signal processor 26 performs signal processing. In addition, the solid-state imaging device 10 records the image signal after the signal processing by the signal processing unit 26 on the medium 36 via the media I / F circuit 34 or displays the image signal on the monitor 38. The image pickup unit 14 is controlled by the amplifier power supply unit 16 and the bias power supply unit 18 according to the processing result. In particular, the timing signal generator 32 is connected to the image pickup unit 14 according to the measurement result by the transfer efficiency measurement unit 200 of the signal processing unit 26. The transfer timing of the horizontal transfer path is changed. Note that portions not directly related to understanding the present invention are not shown and redundant description is avoided. In the following description, the signal is indicated by the reference number of the connecting line in which it appears.

  In the present apparatus 10, for example, the horizontal transfer rate of signal charges in the imaging unit 14 can be changed according to shooting modes such as a still image mode, a moving image mode, and a continuous shooting mode, or according to a scene determination result of a captured image. In this embodiment, transfer is performed at high speed or low speed, and in low speed transfer, the imaging unit 14 outputs one captured image from one output circuit, that is, performs one-line output, and in high speed transfer, the imaging unit 14 is single. A photographed image can be output from two output circuits, that is, one-line output can be performed.

  Although not shown, the optical system 12 has an AF (Automatic Focus) function that forms an image corresponding to the operation of the operation unit 30 by the imaging unit 14 with the incident light 40 from the object scene. The optical system 12 adjusts the angle of view and the focal length according to the zoom operation or half-press operation of the operation unit 30. Further, the optical system 12 has an AE (Automatic Exposure) function that adjusts the incident light 40 to an aperture according to the operation of the operation unit 30 by the imaging unit 14. The optical system 12 adjusts the incident light 40 to the light beam 42 by such a function and emits it to the imaging unit 14.

  The imaging unit 14 includes a solid-state imaging device 44 as shown in FIG. The solid-state imaging device 44 includes a plurality of light receiving elements 46 arranged in the row and column directions, and a color filter segment (not shown) arranged at the position where each light receiving element is disposed on the arrival direction side of the incident light 42. . The solid-state imaging device 44 has a function of color-separating incident light 42 with a color filter segment, converting the separated color component light into signal charges with a light-receiving element 46, and outputting an electrical signal. The solid-state imaging device 44 reads the signal charges accumulated according to the exposure 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 present embodiment, the solid-state imaging device 44 includes a plurality of light receiving elements 46 in the row direction and the column direction, and the light receiving element 46 forms a color filter of three primary colors RGB on the incident light side so that the incident light is red and green. And signal charges belonging to either blue or blue. For example, as shown in FIG. 3, the solid-state imaging element 44 is arranged in a so-called honeycomb arrangement in which the light receiving elements 46 adjacent to one light receiving element 46 are shifted from each other by 1/2 pitch in the row direction and the column direction. The light receiving element 46, for example, arranges green filter segments in a square and red and blue filter segments in a checkered pattern, and arranges them in a so-called G square lattice RB complete checkered pattern.

  The solid-state imaging device 44 is thus arranged by shifting the pixels or the light receiving elements 46, and a vertical transfer path 48 is formed in a meandering manner so as to bypass these pixels. The vertical transfer path 48 directs the signal charge read from each light receiving element 46 to the horizontal transfer path 50 using the line memory LM in accordance with, for example, 8-phase drive signals φV1 to φV8 supplied from the driver 20 Forward.

  The horizontal transfer path 50 of the present embodiment horizontally transfers the vertically transferred signal charge, and a branching portion 54 is formed at the output end 52. In the branch portion 54, horizontal transfer paths 56 and 58 are branched. In the horizontal transfer paths 56 and 58, independent output amplifiers 60 and 62 are formed at the output ends.

  The horizontal transfer paths 50, 56 and 58 have a plurality of transfer elements. For example, as shown in FIG. 4, one transfer element sends a signal to the other adjacent transfer element in accordance with a supplied drive signal. It is for transferring charges. Each transfer element is formed to have two electrodes made of polycrystalline silicon, and each electrode has an impurity layer formed near the surface of the silicon substrate. By applying a drive signal having the same potential to these two electrodes, a step-like potential potential is formed. Similarly, the branch portion 54 is formed of two electrodes and an impurity layer corresponding to them.

  For example, as shown in FIG. 3, the horizontal transfer path 50 of the present embodiment has transfer elements HS 1, HS 2, HS 3, HS 2, HS 1, HS 4, HS 3 and the like from the end contacting the branching portion 54 to the other end. HS4s are formed in that order, and signal charges are sent from each vertical transfer path 48 to one of the transfer elements. The horizontal transfer path 50 of this embodiment can rearrange the signal charges obtained from the light receiving elements arranged in the G square RB complete checkered pattern in the order of output using the line memory LM.

  Further, in the horizontal transfer path 56 of this embodiment, as shown in FIG. 4, transfer elements HP1, HP2, HP1, HP2, and OG (Output Gate) electrodes are formed in this order from the branching section 54 to the output amplifier 60. In the horizontal transfer path 58, transfer elements HP2, HP1, HP2, HP1, HP2, and OG (Output Gate) electrodes are formed in that order from the branching section 54 to the output amplifier 60, as shown in FIG. . In the horizontal transfer paths 56 and 58, a floating diffusion (FD) is formed on the left side of the OG electrode. Further, a reset electrode RS is formed on the left side of the FD. Finally, a reset drain RD is formed on the left side of the reset electrode.

  4 and 5, the solid-state imaging device 44 supplies the drive signal φHS2 supplied from the driver 20 to each electrode of the transfer device HS2 in the horizontal transfer path 50, and the drive signal supplied from the bias power supply unit 18. φHSL is supplied to each electrode HSL of the branching portion 54. The drive signal φHSL is a constant bias voltage. Further, the solid-state imaging device 44 supplies the drive signals φHP1 and φHP2 supplied from the driver 20 to the transfer elements HP1 and HP2 in the horizontal transfer paths 56 and 58, respectively. Further, the solid-state imaging device 44 supplies drive signals φOG, φRS, and φRD supplied from the driver 20 to the electrode OG, the electrode RS, and the reset drain RD, respectively. The electrode OG is supplied with a constant voltage by the drive signal φOG, and the reset drain RD is supplied with a constant power supply voltage by the drive signal φRD.

  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 independently from the amplifier power supply unit 16. 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.

  The output amplifiers 60 and 62 of this embodiment convert the signal charges horizontally transferred from the horizontal transfer paths 56 and 58 into electric signals, respectively, generate two systems of output signals 82 and 84, and send them to the preprocessing unit 22. Output.

  A bias signal 72 is supplied from the bias supply unit 18 to the branch unit 54. By this supply, the signal charge from the horizontal transfer path 50 is branched to one of the horizontal transfer paths 56 and 58. A horizontal serial drive signal 74 is supplied to the horizontal transfer path 50, and a horizontal parallel drive signal 76 is supplied to the horizontal transfer paths 56 and 58. The horizontal parallel drive signal 76 has, for example, a half frequency of the horizontal drive signal 74. By driving the horizontal transfer paths 56 and 58 in this way, high-speed transfer can be performed even if the specification frequency band of the output amplifiers 60 and 62 is a half band. In addition, the solid-state imaging device 44 is supplied with an overflow drain (OFD) pulse 78 and a vertical drive signal 80.

  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 may supply 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 that defines a gain. 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. 6, 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 vertical drive signals 80 such as 8-phase drive signals φV1 to φV8 to the solid-state imaging device 44. The HS driver 96 and the HP driver 98 output a horizontal serial drive signal 74 such as the drive signal φHS2 and a horizontal parallel drive signal 76 such as the drive signals φHP1 and φHP2 to the solid-state imaging device 44, respectively. The horizontal parallel drive signal 76 has a period twice that of the horizontal series drive signal 74. The RS driver 100 outputs reset signals 68 and 70 such as the drive signal φRS to the solid-state imaging device 44.

  The preprocessing unit 22 has an analog front end (AFE) function for analog signal processing of the analog electrical signals 82 and 84 supplied from the imaging unit 14, and removes noise by correlated double sampling (CDS). The analog electric signal from which noise is removed can be digitized, that is, A / D converted and preprocessed.

  The preprocessing unit 22 may have an AFE function corresponding to the output characteristics for each input signal of each system, that is, for each output of the imaging unit 14, and in this embodiment, the outputs 82 and 84 of the imaging unit 14 are provided. Each has an AFE function. The preprocessing unit 22 controls the AFE function for the analog electric signals 82 and 84 in accordance with the timing signals or sampling signals 106 and 108 supplied from the timing signal generator 32, respectively. The preprocessing unit 22 performs analog signal processing on the analog electrical signals 82 and 84 in accordance with the timing signals 106 and 108 to generate digital signals 110 and 112, and outputs them to the memory unit 24.

  The pre-processing unit 22 of the present embodiment inputs two timing signals 106 and 108 with respect to two systems of analog electrical signals 82 and 84, but with one system input by either one of the analog electrical signals. In some cases, only one of the timing signals 106 and 108 can be input to control and operate only the AFE function for the one system input, thereby reducing power consumption. In this case, the pre-processing unit 22 performs analog signal processing on the analog electrical signal 82 or 84 in accordance with the timing signal 106 or 108 to generate a single digital signal 110 or 112 and outputs it to the memory unit 24.

  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 digital signals 110 and 108 input according to the control signal 116 as the digital signal 118 to the signal processing unit 26 via the bus 114 and the signal line 120.

  The signal processing unit 26 performs signal processing on the supplied digital signal 118, and can generate a luminance / color difference signal by, for example, synchronizing the signal 118, for example. The signal processing unit 26 may convert the luminance / color difference signal into, for example, a liquid crystal monitor signal, or may compress the signal into a recording signal. The signal processing unit 26 supplies the recording signal to the media I / F circuit 34 via the signal line 120, the bus 114, and the signal line 136, and outputs a liquid crystal monitor signal 138 to the monitor 38.

  Further, the signal processing unit 26 has a function of generating a control signal according to the digital signal 118. In this embodiment, the power control function unit 122, the gain control function unit 124, the control function unit 122, and the AF control function unit 126, an AE control function unit 128, an AWB (Automatic White Balance) control function unit 130, and an arrangement conversion function unit 132.

  For example, when the system control unit 28 determines whether the horizontal transfer is performed at high speed or low speed, the power control function unit 122 generates a control signal 86 according to the determination result and outputs the control signal 86 to the amplifier power supply unit 16.

  The gain control function unit 124 generates a control signal 88 according to whether the signal charge from the horizontal transfer path 50 is supplied from the branching unit 54 to any of the horizontal transfer paths 56 and 58, and outputs the 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 126 has a function of performing AF adjustment based on the digital signal 118. The AE control function unit 128 has a function of adjusting the aperture and shutter speed using the AE evaluation value determined based on the digital signal 118, that is, performing AE adjustment. The AF control function unit 126 and the AE control function unit 128 send control signals (not shown) corresponding to AF adjustment and AE adjustment to the system control unit 28 via the signal line 120, the bus 114, and the signal line 134. The AWB control function unit 130 has a function of adjusting the white balance of the image indicated by the signal 118 based on the digital signal 118.

  The arrangement conversion function unit 132 receives the digital image signal 118 indicating two pieces of image data when the image pickup unit 14 outputs the two lines and transfers them at high speed, and inputs these two pieces of image data into, for example, an image color filter segment. It has the function which correct | amends in order of the dot sequence corresponding to the arrangement | sequence, and synthesize | combines it to one image. The arrangement conversion function unit 132 receives the digital signal 118 from the single system output when the imaging unit 14 outputs the single system and performs low-speed transfer, and performs an array conversion process for the single system output.

  Based on the digital image signal 118, the transfer efficiency measuring unit 200 measures the transfer efficiency of signal charges passing through the horizontal transfer paths 56 and 58 from the branching unit 54, that is, the transfer efficiency of the horizontal transfer paths 56 and 58.

  The transfer efficiency measuring unit 200 of the present embodiment measures the horizontal transfer efficiency of the horizontal transfer paths 56 and 58 in advance, for example, when the apparatus 10 is shipped from the factory, and any of the horizontal transfer paths according to the measurement result. It is preferable to determine whether the transfer efficiency is good and store the determination result in a storage unit (not shown). Further, the transfer efficiency measurement unit 200 may store the measurement result, that is, the horizontal transfer efficiency itself in a storage unit (not shown), and cause the system control unit 28 to determine the horizontal transfer efficiency.

  The system control unit 28 is a control function unit that controls and controls the overall operation of the apparatus in response to an operation signal 140 supplied from the operation unit 30. The system control unit 14 of this embodiment can generate a control signal 142 in response to the operation signal 140 and supply it to the timing signal generator 16 to control it. For example, the output operation by horizontal transfer is 1 output and 2 output. A control signal 142 for controlling either of the above is generated. The system control unit 28 determines whether to perform horizontal transfer at high speed or low speed according to, for example, moving image mode setting, continuous shooting speed setting, scene determination, and release shutter button pressing operation, and according to the determination result The control signal 142 is output to the timing signal generator 32. The system control unit 28 also controls other circuits such as the memory unit 24, the signal processing unit 26, and the media I / F circuit 34.

  In addition, when the transfer efficiency measurement unit 200 stores the measurement result in a storage unit (not shown), the system control unit 28 has a function of determining which horizontal transfer path has good transfer efficiency according to the measurement result. The timing signal generator 16 may be supplied with a control signal corresponding to the determination result by the control unit 28 or the transfer efficiency measuring unit 200.

  The operation unit 30 is a manual operation device that inputs an operator's instruction, and supplies an operation signal 140 to the system control unit 14 in accordance with an operator's manual operation state, for example, a stroke operation of a shutter button (not shown). It has the function to do. Although not shown, the operation unit 30 may include, for example, a power switch, a zoom button, a menu display changeover switch, a selection key, a moving image mode setting unit, a continuous shooting speed setting unit, and a release shutter button.

  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. This function generates various timing signals 90, 106 and 108 in response to a 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. In response to the control signal 142 from the system control unit 28, the timing signal generator 32 outputs at least one of the sampling signals 106 and 108 to output one system. By operating in this way, power consumption of the digital camera 10 can be suppressed.

  In this embodiment, the timing signal generator 32 inputs a determination result indicating which horizontal transfer efficiency of the horizontal transfer paths 56 and 58 is good from the transfer efficiency measuring unit 200 or the system control unit 28, and the determination result is Accordingly, the driving condition of the horizontal timing signal for the horizontal transfer path 50 can be changed accordingly. For example, the initial driving condition of the horizontal timing signal for the horizontal transfer paths 56 and 58 is shifted by shifting the drive disclosure time in the initial driving condition of the horizontal timing signal. Can be relatively shifted from the drive disclosure time at.

  For example, when the timing signal generator 32 controls the horizontal transfer path 50 and the branch unit 54 by supplying the horizontal timing signal of the initial driving condition at the time of high-speed driving to the driver 20 and controlling the horizontal transfer path 50 and the branch unit 54, the green signal charge is transferred to the horizontal transfer path In addition, red and blue signal charges are alternately transferred to the horizontal transfer path 58. The timing signal generator 32 shifts the horizontal timing signal of the initial driving condition relatively, and delays it by one cycle, for example, or supplies it to the driver 20 earlier to control the horizontal transfer path 50 and the branching unit 54. Red and blue signal charges are alternately transferred to the path 56, and green signal charges are transferred to the horizontal transfer path 58.

  The timing signal generator 32 of this embodiment shifts the horizontal timing signal of the initial drive condition in this way to determine the reverse branch drive condition, reverses the signal charge transferred to the horizontal transfer paths 56 and 58, and outputs it. The electric signals output from the amplifiers 60 and 62 can be reversed.

  For example, the timing signal generator 32 determines a desired driving condition at the time of high-speed driving according to the determination result of the horizontal transfer efficiency, and selects a horizontal transfer path with a good horizontal transfer efficiency among the horizontal transfer paths 56 and 58. On the other hand, signal charges for which good horizontal transfer is desired, for example, red and blue signal charges can be transferred.

  In addition, since the timing signal generator 32 transfers all signal charges to only one of the horizontal transfer paths 56 and 58 during low-speed driving, it is driven at low speed according to the determination result of the horizontal transfer efficiency. It is possible to transfer all signal charges to a horizontal transfer path having good horizontal transfer efficiency among the horizontal transfer paths 56 and 58 by determining a desired driving condition at the time.

  The media I / F circuit 34 has an interface control function for controlling recording / reproduction of image data in accordance with, for example, a recording medium to be handled. The media I / F circuit 34 controls writing / reading of image data 144 to / from a PC (Personal Computer) card which is a semiconductor recording medium or an image supplied via a bus 144 when a USB (Universal Serial Bus) controller is built in. Data 136 can be written / read out. The media 36 has various semiconductor card standards.

  As the monitor 38, a liquid crystal monitor or the like is used. The monitor 38 displays the image data 138 supplied from the signal processing unit 26.

  With this configuration, the apparatus 10 can operate optimally because the signal charge from the horizontal transfer path 50 is transferred at high speed and output in two lines, and is transferred at low speed and output in one line. .

  Next, the electrode structure for branching the horizontal transfer path 50 into two horizontal transfer paths 56 and 58 at the branching section 54 and the transfer of signal charges according to the drive signal will be described. For ease of explanation, the description will be divided into a branch and one horizontal transfer path 56 side, and a branch and one horizontal transfer path 58 side.

  The timing for these drive signals is shown in FIG. Focusing on the phase of each drive signal, the drive signals φHS1 and φHS3 in FIG. 7A are two-phase drive signals that are 180 ° out of phase with the drive signals φHS2 and φHS4 in FIG. 7B. Further, the drive signal φHP1 in FIG. 7C and the drive signal φHP2 in FIG. 7D are in opposite phases and are two-phase drive signals.

  Further, paying attention to the cycle of the drive signal, the drive signals of the set of FIGS. 7A and 7B have a half cycle of FIGS. 7C and 7D. That is, the drive signals in the sets of FIGS. 7A and 7B have double the frequencies of FIGS. 7C and 7D. As shown in FIG. 7E, the drive signal φRS supplies the level “H” at timings t1, t5,... And 4n + 1, for example. The variable n is an integer including zero. The output signals OS1 and OS2 are output as shown in FIG.

  Next, as shown by the one-dot chain line IV-IV in FIG. Referring to FIG. 8, the transition of the potential potential in the horizontal transfer path 50, the branching section 54, and the call horizontal transfer path 56 will be described with reference to the potential potential change diagram of FIG.

  As shown in the fractured surface of FIG. 4, an impurity layer is formed immediately below the P-type silicon substrate (not shown) and each electrode. This impurity layer is divided according to the size of each electrode. The separated impurity layer is doped with an impurity using an ion implantation method or the like, and the potential potential is characterized by 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.

  As shown in FIG. 8A, when the drive signal φHSL is supplied, the potential potential of the fixed reference level 146 and the horizontal transfer path 50 are always supplied immediately below the electrode HSL to which the drive signal φHSL is supplied. A potential barrier or barrier 148 is formed to prevent backflow of the signal charge that is generated.

  The potential formed according to the supplied drive signal and the movement of the signal charge accompanying this potential formation will be described. Signal charges having color attributes R, G, and B are referred to as signal charges R, G, and B, respectively. At time t1, as shown in FIG. 7B, the drive signal φHS2 is supplied with the level “L”, the drive signal φHSL, and the drive signal φHP1. The drive signal φHP1 is at level “L”.

  When the drive signal is applied in this way, the signal charge R is held in the branching portion 54 as shown in FIG. At this time, the impurity layer of the electrode HP1 (not shown) adjacent to the electrode HSL generates a potential potential or a barrier indicated by a broken line 150 to such an extent that the signal charge R does not enter the horizontal transfer path 56 by supplying the level “L”. .

  Further, the drive signal φHP2 of level “H” is supplied to the other electrode HP2 adjacent to the branch portion. By this supply, a potential potential 152 lower than the reference level is generated so that the signal charge R flows into the horizontal transfer path 58. At this time, the signal charge R exists in both the reference level 146 and the potential potential 152 packets.

  Immediately below the electrodes HP2 and HP1, impurity layers 154 and 156 are formed. When the level “H” is supplied, the potential potential is one level lower than the reference level 146 and the deepest level is formed stepwise. When the level “L” is supplied, the potential potential is one level higher than the reference level 146 and the same level as the reference level 146. As a result, the level of the potential formed decreases stepwise in the direction toward the signal charge transfer direction. Every other signal charge G is held in the horizontal transfer path 56 at time t1.

  Next, at time t2, as shown in FIG. 7B, the drive signal φHS2 is applied to the electrode HS2 at the level “H”. Further, as shown in FIG. 8B, this application generates a potential potential 148 and a reference level 146 in the impurity layer of the electrode HS2. Due to the formation of this potential potential, the electrode HS2 forms a packet with the electrode HSL. A signal charge G is held in this packet. Subsequent electrodes are supplied with drive signals at the same level as at time t1. Therefore, the potential potential formed is the same as that at time t1. During this time, the signal charge R of the electrode HSL moves to the electrode HP2 on the horizontal transfer path 58 located on the front side of the paper (not shown). This actual signal charge R is indicated by a broken line.

  Next, as shown in FIG. 8C, at time t3, the drive signal φHS2 is applied to the electrode HS2 at the level “L”. By this application, the potential potential becomes the state at time t1. The signal charge G held in the packet formed at time t2 moves to the reference level 146 of the branching portion 54 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 in the impurity layer corresponding to the electrode HP1 is lower than the reference level 146 as shown by the broken line 158. As a result, the signal charge G is present in both the reference level 146 and potential potential 160 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 potential indicated by a broken line 158 is generated at the electrode HP2. This potential potential prevents the signal charge G from entering the horizontal transfer path 58. The signal charge G of the branching portion 54 moves toward a packet formed on the electrode HP1 of the horizontal transfer path 56 on the back side of the paper (not shown).

  A drive signal φHP2 of level “L” is applied to the electrode HP2 adjacent to the electrode HP1. Thus, impurity layers 154 and 156 form a potential potential 148 and a reference level 146 level. A drive signal φHP1 of level “H” is applied to the electrode HP1 adjacent to the electrode HP2. Thus, impurity layers 154 and 156 form a deepest potential potential and a level one step lower than reference level 146. 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 G held in the packet at time t2 moves to and is held in the packet formed on the electrode HP1.

  Further, the signal charge G of the electrode HP2 held in the packet formed at the time t2 is moved toward the output side due to the increase in potential potential, and is transferred to the FD via the electrode OG.

  Next, as shown in FIG. 8D, the electrode HS2 is supplied with the driving signal φHS2 of level “H” at time t4, thereby forming the same potential as at time t2. At this time, the signal charge B is held in the formed packet. The signal charge G in the branch portion 54 moves to a packet formed immediately below the electrode HP1 of the horizontal transfer path 56. Subsequent electrodes are respectively supplied with drive signals at the same level as at time t3. Therefore, the formed potential potential is the same as that at time t3.

  Next, as shown in FIG. 8E, at time t5, the impurity layer corresponding to the electrode HS2 forms the same potential potential as at time t1. As a result, a potential potential 152 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 at time t1. Therefore, the potential potential formed is the same as that at time t1. At time t4, the signal charge G supplied to the FD is converted into an analog voltage signal and sent to the output amplifier 60.

  Next, as shown by a one-dot chain line VII-VII in FIG. 5, a sectional view in which the reset drain RD at the left end to the electrode HP2 of the horizontal transfer path 58 and further from the branch portion 54 to the electrode HS2 of the horizontal transfer path 50 are broken. With reference to FIG. 9, the transition of the potential potential in the horizontal transfer path 50, the branching unit 54, and the call horizontal transfer path 58 will be described with reference to the potential potential change diagram of FIG.

  As shown in the fracture surface of FIG. 5, an impurity layer is formed immediately below the P-type silicon substrate (not shown) and 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 concentration of impurities so that a predetermined potential 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.

  At time t1, as shown in FIG. 7B, the level “H” driving signal φHS2, 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. The

  When each drive signal is applied in this way, the signal charge R is held in the branching section 54 as shown in FIG. At this time, the potential potential generated by the impurity layer of the broken electrode HP2 (not shown) adjacent to the electrode HSL becomes a level 152 that is lower by one step than the reference level 146, the potential potential generated by the application of the drive signal φHP2. Further, the potential potential 150 formed immediately below the electrode HP1 of the horizontal transfer path 56 functions as a potential barrier and prevents the signal charge R from being mixed.

  In addition, the electrode HP1 and the electrode HP2 are alternately arranged after the electrode HP2, and four electrodes are formed. Therefore, the horizontal transfer path 58 is provided with one electrode more than the horizontal transfer path 56. For example, impurity layers 154 and 156 of FIG. 4 are formed in order from the right in the impurity layers immediately below these four electrodes. 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 level one level lower than the reference level 146 and the deepest potential potential are formed immediately below the electrode HP2.

  At time t1, since the drive signal is supplied as described above, a packet is formed immediately below the electrode HP2. The signal charges B and R are held in the packet in order from the branching unit 54.

  Next, at time t2, as shown in FIG. 7B, a drive signal φHS2 of level “H” is applied to the electrode HS2. By this application, as shown in FIG. 9B, the impurity layer of the electrode HS2 generates a potential potential at the same level as the time t2 in FIG. 8 to form a packet. A signal charge G is held in this packet. Thereafter, the drive signals at the same level as at time t1 are supplied to the electrodes of the horizontal transfer path 58, respectively. Therefore, the potential formed is the same as at time t = 1.

  Next, the potential at time t3 is shown in FIG. At time t3, the drive signal φHS2 is applied to the electrode HS2 at the level “L”. By this application, the potential becomes the state at time t1. The signal charge G held in the packet immediately below the electrode HS2 at time t2 moves to the branch portion 54 at 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 electrode HP2 is slightly higher than the reference level 146, as indicated by a broken line 158, due to the impurity layer corresponding to the electrode HP2 removed by the fracture. That is, a potential barrier is formed. With this formation, the signal charge G is not mixed into the horizontal transfer path 58. On the other hand, the potential “H” supplied to the electrode HP1 of the horizontal transfer path 56 forms a potential potential indicated by a broken line 152b. Thereby, the signal charge G moves toward the back side of the paper surface indicated by the arrow 162. A packet is formed by the potential potential 160 immediately below the electrode HP1 to which the drive signal φHP1 is supplied in the horizontal transfer path 56, as shown at time t1 in FIG.

  In the horizontal transfer path 58, a packet formed on the electrode HP2 at time t2 in response to the supply of the level “H” of the drive signal φHP1 is formed on the electrode HP1. The signal charges R and B are held in the packet of the electrode HP1 in order from the branching part 54. The signal charge R of the electrode HP2 held in the packet formed at time t2 is moved toward the output side due to the increase in potential potential, and is transferred to the FD via the electrode OG.

  Next, as shown in FIG. 9D, the same potential as that at time t2 is formed immediately below the electrode HS2 at time t4. At this time, the signal charge B is held in the formed packet. Subsequent electrodes are respectively supplied with drive signals at the same level as at time t3. Therefore, the potential formed is the same as at time t3. The potential potential formed immediately below the electrode HP2 adjacent to the electrode HSL is at a potential higher than the reference level 146, as indicated by a broken line 158. Further, the potential potential formed immediately below the electrode HP1 adjacent to the electrode HSL is in a potential state lower than the reference level 146, as indicated by a broken line 160.

  Next, as shown in FIG. 9E, the same potential as at time t1 is formed at time t5. In order from the branching portion 54, signal charges R and B are held in the packet of the electrode HP2. At time t4, the signal charge R supplied to the FD is converted into an analog voltage signal and output from the output amplifier 60.

FIG. 10 shows the operation principle of horizontal transfer according to the supply of the drive signal. In the horizontal transfer, as shown in FIG. 10 (A), for example, signal charge R # G ₁ # B # G ₂ supplied from the horizontal transfer path 50 to the branching unit 54 at time t1 is transferred horizontally by the branching unit 54. They are assigned to roads 56 and 58. Here, the symbol # represents a potential barrier region. It can be seen that a potential barrier for separating signal charges is formed for each electrode in the horizontal transfer path of FIG. The horizontal transfer path 56 transfers only the signal charge G according to the supplied drive signal. At this time, a potential barrier is formed at the electrode HP1 of the horizontal transfer path 56 adjacent to the branch portion 54. The signal charge R is prevented from entering the horizontal transfer path 56. Further, the horizontal transfer path 58 transfers the signal charges R and B in accordance with the supplied drive signal.

  The horizontal transfer path 50 is operated at a frequency twice that of the horizontal transfer paths 56 and 58. As a result, as shown in FIG. 10B, at time t2, the horizontal transfer path 50 horizontally transfers the signal charge held in accordance with the supplied drive signal toward the branch unit 54 for one packet. On the other hand, since the level of the drive signal supplied to the horizontal transfer path 56 does not change, the signal charge transfer does not change. 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 R of the branching portion 54 moves to a packet formed on the electrode HP2 because a potential potential lower than the reference level 146 is formed.

Also, as shown in FIG. 10C, at time t3, the horizontal transfer path 50 horizontally transfers the held signal charge toward the branching unit 54 for one packet. The packet to be formed immediately below the electrode HP1 of the horizontal transfer path 56 adjacent to the branch portion 54 and branch portion 54, the signal charges G ₁ is held. At this time, a potential barrier is formed on the electrode HP2 of the horizontal transfer path 58 adjacent to the branch portion. The signal charge G ₁ is prevented 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 branch unit 54 for one packet. As a result, the signal charge G 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, as shown in FIG. 10 (D), at time t4, the horizontal transfer path 50 horizontally transfers the signal charges held in accordance with the supplied drive signal toward the branch unit 54 for one packet. Signal charge G ₁ is moved to a packet to be formed immediately below the electrode HP1 of the horizontal transfer path 56 adjacent to the branch portion 54. Further, the signal charge R moves to a packet formed immediately below the electrode HP1 of the horizontal transfer path 58 adjacent to the branch portion.

  As shown in FIG. 10 (E), at time t5, the horizontal transfer paths 50, 56 and 58 horizontally transfer the held signal charges toward the output side for one packet. As a result, the signal charges of the colors G and B are simultaneously converted into analog voltage signals from the output amplifiers 60 and 62 and output as output signals OS1 and OS2. Output signals OS1 and OS2 are processed in parallel. Thereby, it is possible to eliminate the time-series processing difference between the output signals OS1 and OS2.

  Note that the output signals OS1 and OS2 may be alternately output as long as the difference in time-series processing is acceptable.

  By operating the signal charges in this way, the signal charges having color attributes can be classified, transferred, and output without being mixed. In general, a solid-state imaging device is required to transfer a signal charge obtained with an increase in the number of pixels at high speed. This requirement affects the frequency band in the output amplifier of the horizontal transfer path. A solid-state imaging device is difficult to drive at a certain frequency or more and is due to a lack of frequency bands. However, the solid-state imaging device 44 of the present embodiment allows the driving frequency of the output units 60 and 62 to be increased by branching and increasing the output even if the driving frequency of the horizontal transfer path 50 is increased corresponding to the increase in the number of pixels. Even if it is not increased, the output signal charge can be transferred within a predetermined frequency band according to the color. That is, an improvement in the transfer rate of signal charges can be realized.

  In this embodiment, the signal charges obtained from the light receiving elements arranged as shown in FIG. 3, that is, the light receiving elements arranged in the G square RB perfect checkered pattern, are transferred to the line memory LM in the horizontal transfer path 50. It is rearranged in the order of output using.

  As shown in FIG. 11 and FIG. 12, this rearrangement is performed by the drive signal φLM supplied to the line memory LM (A) and the drive signal supplied to the electrodes of the horizontal transfer path 50 (B) to (E). Use φHS1 to φHS4. In this rearrangement, as shown in FIGS. 11 and 12 (F) and (G), the drive signals φHP1 and φHP2 that do not change the temporal level are supplied to the horizontal transfer paths 56 and 58. With this supply, the horizontal transfer paths 56 and 58 do not operate.

  The timing chart of FIG. 11 shows the rearrangement of the first field during the horizontal blanking (HBL) period. First, the drive signal φLM of FIG. 11A becomes level “L” at time t174. At this time, the drive signal of level “H” is only the drive signal φHS2 of FIG. A signal charge is transferred from the line memory LM to a packet formed immediately below the electrode HS2 of the horizontal transfer path 50 to which the drive signal φHS2 is supplied.

  Next, the drive signal φHS1 of FIG. 11B supplied to the electrode HS1 becomes level “H”. As a result, a packet is formed immediately below the electrode HS1, and the signal charge is moved. Next, the drive signal φHS4 of FIG. 11 (E) supplied to the electrode HS4 becomes level “H”. As a result, a packet is formed immediately below the electrode HS4, and the signal charge is moved. Further, the drive signal φHS3 of FIG. 11D supplied to the electrode HS3 next becomes the level “H”. As a result, a packet is formed immediately below the electrode HS3, and the signal charge is moved. Next, the drive signal φLM of FIG. 11A becomes level “L” at time t176. Only the drive signal φHS1 in FIG. 11B becomes level “H”. As a result, the signal charge is supplied to the packet and held.

  Next, the timing chart of FIG. 12 shows the rearrangement of the second field during the horizontal blanking (HBL) period. First, the drive signal φLM of FIG. 12A becomes level “L” at time t178. At this time, the drive signal of level “H” is only the drive signal φHS4 of FIG. Signal charges are transferred from the line memory LM to a packet formed immediately below the electrode HS4 of the horizontal transfer path 50 to which the drive signal φHS4 is supplied. Next, the level “H” is supplied in the order of FIGS. 12 (B), (C), (D), (C) and (B) according to the arrangement of the electrodes. As a result, the signal charge is moved as the formed packet is moved. That is, the first signal charge is sequentially moved to the electrodes HS4, HS1, HS2, HS3, HS2, and HS1. The first signal charge is temporarily held on the electrode HS1.

  Next, the drive signal φLM in FIG. 12A becomes level “L” at time t180. At this time, the drive signal of level “H” is only the drive signal φHS3 in FIG. The second signal charge is transferred from the line memory LM to a packet formed immediately below the electrode HS3 of the horizontal transfer path 50 to which the drive signal φHS3 is supplied. Next, the level “H” is supplied in the order of FIGS. 12C and 12B according to the arrangement of the electrodes. In this order, the second signal charge read at time t180 moves the packet to the electrode HP2 to be formed. Almost simultaneously with this movement, the first signal charge held in the second field is moved to the electrode HS4. Next, the first signal charge held on the electrode HS4 is moved to the electrode HS3.

  By rearranging in this way, two rows of signal charges RGBGRGBG... Read from the lowermost end in FIG. 3 are arranged as the first field. In addition, the two rows of signal charges BGRGBGRG... Read from the top of the two rows are arranged as a second field.

  Here, this rearrangement is a technique used in the case of the G square RB complete checkered pattern in the honeycomb arrangement. In another arrangement pattern, rearrangement is unnecessary or the timing is different. Such rearrangement may be applied to general square pixels.

  Next, in the solid-state imaging device 10 of the present embodiment, an operation of performing horizontal transfer under initial drive conditions during high-speed transfer will be described with reference to the timing chart of FIG.

  13A to 13G show an operation in the case where the timing signal generator 32 supplies a horizontal timing signal of an initial driving condition to the driver 20. Here, FIGS. 13 (A) and (B) show drive signals φHS1 and φHS3, and drive signals φHS2 and φHS4 output by the HS driver 96 to the horizontal transfer path 50, respectively, and FIGS. (D) shows drive signals φHP1 and φHP2 output from the HP driver 98 to the horizontal transfer paths 56 and 58, respectively. 13E shows the reset signal φRS output from the RS driver 100 to the output amplifiers 60 and 62. FIGS. 13F and 13G show the outputs of the output amplifiers 60 and 62, respectively. Output signals OS1 and OS2 are shown.

  In the horizontal transfer path 50 of the present embodiment, the signal charges transferred from each vertical transfer path 48 are rearranged in the output order in the horizontal blanking period, and for example, from the end in contact with the branching section 54 at time t202. Dummy pixel D1, dummy pixel D2, optical black pixel OB1, optical black pixel OB2, R pixel, G pixel, B pixel, G pixel, etc. are accumulated in that order in each transfer element toward the other end. It is assumed that

  In the present embodiment, in the driver 20, a horizontal serial drive signal 74 activated at time t204 is generated by the HS driver 96 in accordance with the horizontal timing signal of the initial drive condition, and the drive signals φHS1 and φHS3 as the drive signal 74, and Drive signals φHS2 and φHS4 are supplied to the horizontal transfer path 50. In the driver 20, a horizontal parallel drive signal 76 activated at time t 206 is generated by the HP driver 98, and drive signals φHP 1 and φHP 2 are supplied to the horizontal transfer paths 56 and 58 as the drive signal 74.

  First, in the horizontal transfer path 50, each signal charge is horizontally transferred toward the branching unit 54.In this embodiment, the dummy pixel D1, the dummy pixel D2, the optical black pixel OB1, the optical black pixel OB2, R pixel, Transfer is performed in the order of G pixel, B pixel, G pixel,.

  At this time, each signal charge is alternately branched and transferred from the branch portion 54 to the horizontal transfer paths 56 and 58. This branch transfer will be described later. Each signal charge is first sent to the horizontal transfer path 58 to which the horizontal parallel drive signal φHP2 at level “H” is supplied at time t204, and then the horizontal parallel drive signal φHP1 at level “H” at time t206. In this embodiment, the dummy pixel D1, the optical black pixel OB1, the R pixel, and the B pixel are sent in that order to the horizontal transfer path 58 side, and the horizontal transfer is performed in this embodiment. The dummy pixel D2, the optical black pixel OB2, the G pixel, and the G pixel are sent to the path 56 side in that order.

  The signal charges sent to the horizontal transfer paths 56 and 58 are transferred to the output amplifiers 60 and 62, converted into analog electric signals, and output. In the output amplifier 60 of the present embodiment, as shown in FIG. 13 (F), in each output period t182, t184, t186 and t188, the dummy pixel signal D2, the optical black pixel signal OB2, the G pixel signal, and The G pixel signal is sequentially output as the output signal OS1, that is, the analog electric signal 82.

  Further, in the output amplifier 62, as shown in FIG. 13G, in each output period t182, t184, t186, and t188, the dummy pixel signal D2, the dummy pixel signal D1, and the optical black pixel signal OB1, R, respectively. The pixel signal and the B pixel signal are sequentially output as the output signal OS2, that is, the analog electric signal 84.

  As described above, in the imaging unit 14, when the horizontal transfer is performed under the initial driving condition, the horizontal transfer path 56 and the output amplifier 60 output the output signal OS1 indicating the color signal of the G pixel, and the horizontal transfer path 58 and the output amplifier 62. Outputs an output signal OS2 indicating the color signals of the R and B pixels.

  Next, in the solid-state imaging device 10 of the present embodiment, an operation of performing horizontal transfer by shifting the horizontal timing signal from the initial driving condition during high-speed transfer will be described with reference to the timing chart of FIG.

  14A to 14G, the operation when the timing signal generator 32 supplies the driver 20 with a horizontal timing signal delayed by one cycle from the initial drive condition, for example, the cycle t190, that is, the reverse branch drive condition. It is shown. Here, FIGS. 14 (A) and 14 (B) show drive signals φHS1 and φHS3 and drive signals φHS2 and φHS4 output by the HS driver 96 to the horizontal transfer path 50, respectively, and FIG. ) And (G) show output signals OS1 and OS2 output from the output amplifiers 60 and 62, respectively. In this case, the drive signals φHP1 and φHP2 and the reset signal φRS may be the same signals as those shown in FIGS. 13C and 13D and FIG. 13E.

  Also in this embodiment, in the same manner as described above, in the horizontal transfer path 50, at time t202, each transfer element includes a dummy pixel D1, a dummy pixel D2, an optical black pixel OB1, an optical black pixel OB2, an R pixel, Assume that G pixels, B pixels, G pixels,... Are accumulated.

  In this embodiment, first, in the same manner as described above, the HP driver 98 generates the horizontal parallel drive signal 76 that starts at time t206, and the drive signals φHP1 and φHP2 are supplied to the horizontal transfer paths 56 and 58 as this drive signal 74. Supplied. Further, in the HS driver 96, a horizontal serial drive signal 74 activated at a time t208 is generated by the HS driver 96 in accordance with the horizontal timing signal of the reverse branch drive condition, and the drive signals 74HS1 and φHS3 as the drive signal 74, and Drive signals φHS2 and φHS4 are supplied to the horizontal transfer path 50.

  Next, in the horizontal transfer path 50, each signal charge is horizontally transferred toward the branch portion 54, and in this embodiment, the dummy pixel D1, the dummy pixel D2, the optical black pixel OB1, the optical black pixel OB2, and the R pixel. , G pixel, B pixel, G pixel,...

  At this time, each signal charge is alternately branched and transferred from the branching unit 54 to the horizontal transfer paths 56 and 58, and is branched and transferred in the order reverse to the horizontal transfer of the initial drive condition. Each signal charge is first sent to the horizontal transfer path 56 to which the horizontal parallel drive signal φHP1 having the level “H” is supplied at time t208, and then the horizontal parallel drive signal φHP2 having the level “H” is supplied at time t210. In this embodiment, dummy pixels D1, optical black pixels OB1, R pixels, and B pixels are sent in that order to the horizontal transfer path 56 side, and in the present embodiment, the horizontal transfer path 58 The dummy pixel D2, the optical black pixel OB2, the G pixel, and the G pixel are sent to the path 58 side in that order.

  Next, the signal charges in the horizontal transfer paths 56 and 58 are transferred to the output amplifiers 60 and 62, respectively. In the output amplifier 60, as shown in FIG. 14 (F), the dummy pixel signal D1, the optical black pixel signal OB1 , The R pixel signal and the B pixel signal are output as output signals OS1 in the output periods t182, t184, t186, and t188, respectively, and in the output amplifier 62, as shown in FIG.14 (G), dummy pixel signals D2, The optical black pixel signal OB2, the G pixel signal, and the G pixel signal are output as the output signal OS2 in the output periods t182, t184, t186, and t188, respectively.

  As described above, in the imaging unit 14, when the horizontal transfer is performed under the reverse branch driving condition, the horizontal transfer path 56 and the output amplifier 60 output the output signal OS1 indicating the color signals of the R pixel and the B pixel, and the horizontal transfer path The output signal OS2 indicating the color signal of the G pixel is output from 58 and the output amplifier 62.

  Next, in the solid-state imaging device 10 of the present embodiment, an operation related to horizontal transfer at the time of low-speed transfer will be described with reference to the timing chart of FIG.

  FIGS. 15A to 15G show the operation when the timing signal generator 32 supplies the horizontal timing signal of the initial driving condition to the driver 20. Here, in FIGS. 15A and 15B, horizontal serial drive signals φHS1 and φHS3 output by the HS driver 96 to the horizontal transfer path 50 and horizontal serial drive signals φHS2 and φHS4 are shown, respectively. C) and (D) show horizontal parallel drive signals φHP1 and φHP2 output from the HP driver 98 to the horizontal transfer paths 56 and 58, respectively. FIG. 15E shows the reset signal φRS output from the RS driver 100 to the output amplifiers 60 and 62. FIGS. 15F and 15G show the output signals from the output amplifiers 60 and 62, respectively. Output signals OS1 and OS2 are shown.

  In this embodiment, the horizontal serial drive signals φHS1, φHS2, φHS3 and φHS4 and the horizontal parallel drive signals φHP1 and φHP2 are output at the same frequency. As shown in FIG. 15, when the drive signal φHS2 supplied to the final electrode HS2 of the horizontal transfer path 50 becomes level “L” at time t212, the drive signal φHP1 supplied to the electrode HP1 is set to level “H”. In addition, the drive signal φHP2 supplied to the electrode HP2 becomes the level “L”, and the signal charge in the final electrode HS2 is always transferred to the electrode HP1, that is, the horizontal transfer path 56 side via the branch portion (HSL) 54. The

  Further, in the solid-state imaging device 44, as shown in FIG. 15 (F), an output signal OS1 indicating one of the color signals is output from the output amplifier 60, and as shown in FIG. 15 (G), the level “L”. Is output from the output amplifier 60.

  In this way, at the time of low speed driving, only one output signal OS1 is output from the solid-state imaging device 44, and the output signal OS2 is not used. Therefore, the power of the output amplifier 62 may be turned off. In this case, the power supply 66 may be turned off by controlling the power supply of the amplifier power supply unit 16 according to the control signal 86 from the power supply control function unit 122.

  In horizontal transfer during low-speed transfer, the system controller 28 and the timing generator 32 control the driver 20 to reverse the phase of the drive signals φHP1 and φHP2, or the phase of the drive signals φHS1 and φHS3 and the drive signal By reversing the phases of φHS2 and φHS4, the solid-state imaging device 44 can operate only the horizontal transfer path 58 and the output amplifier 62 side and output the output signal OS2 in one line.

  In this way, it is possible to easily switch between 1-line output and 2-line output and freely select the output. When dynamic range priority is selected at low sensitivity, an output amplifier with low charge detection sensitivity is selected. When sensitivity priority is selected at high sensitivity, an output amplifier with high charge detection sensitivity is selected.

  Next, an example of an operation for measuring transfer efficiency in the solid-state imaging device 10 of the present embodiment will be described.

  When measuring the transfer efficiency in the branch section 54 and the horizontal transfer paths 56 and 58, the apparatus 10 mixes signal charges in the horizontal transfer path 50 in the horizontal pixel, and two systems in the branch section 54 and the horizontal transfer paths 56 and 58. The driver 20 drives and controls the imaging unit 14 so as to output.

  The horizontal transfer path 50 accumulates reference signal pixels in which a plurality of signal charges are mixed by this horizontal pixel mixing and empty pixels that have lost charges due to this mixing, as shown in FIG. A group 220 consisting of a plurality of pixels, in which two or more empty pixels Emp1 and Emp2 follow the pixel Sig, is repeatedly created. The horizontal transfer path 50 horizontally transfers such a group 220 including a plurality of pixels Sig, Emp1, and Emp2 to the branching unit 54.

  Here, when the branch unit 54 and the horizontal transfer paths 56 and 58 are driven and controlled according to the horizontal timing signal of the initial drive condition, for example, the branch unit 54 is connected to the pixel Sig of the reference signal on the horizontal transfer path 56 side. The second empty pixel Emp2 is sent, and the first empty pixel Emp1 is sent to the horizontal transfer path 58 side.

  At this time, in the horizontal transfer by the horizontal transfer path 56, the signal charge left when the pixel Sig of the reference signal is transferred enters the second empty pixel Emp2, and is transferred from the branch unit 54 to the horizontal transfer path 58. , The signal charge left when the reference signal pixel Sig is transferred enters the first empty pixel Emp1.

  The signal charge amount of the first and second empty pixels Emp1 and Emp2, that is, the residual transfer of the horizontal transfer path 56 left before reaching the output amplifier 60 from the branching section 54 through the horizontal transfer path 56 As shown in FIG. 18, the charge amount 232 changes according to the pixel Sig of the reference signal, that is, the reference signal charge amount.

  Thereafter, the output amplifier 60 outputs the output signal 82 including the pixel Sig of the reference signal and the second empty pixel Emp2, and the preprocessing unit 22 performs analog signal processing on the output signal 82 to generate the digital signal 110. Stored in the memory 24. Similarly, the horizontal transfer path 58 and the output amplifier 62 output an output signal 84 including the first empty pixel Emp1, and the preprocessing unit 22 stores the digital signal 112 based on the output signal 84 in the memory 24.

  Further, the signal processing unit 26 reads the reference signal pixel Sig, the second empty pixel Emp2, and the first empty pixel Emp1 from the memory 24 through the bus 114 and the signal line 120 as the digital signal 118.

  In the signal processing unit 26, the transfer efficiency measurement unit 200 obtains the transfer residual charge amount 232 of the horizontal transfer path 56 based on the first empty pixel Emp 1 and the second empty pixel Emp 2, and Of the transfer efficiency (Horizontal Transfer Rate: HTR), the horizontal transfer efficiency HTR11 related to the transfer from the branching unit 54 to the horizontal transfer path 56 can be calculated based on the reference signal charge amount Sig and the transfer residual charge amount Emp1. The horizontal transfer efficiency HTR12 related to the transfer to the electrodes OG and FD in the horizontal transfer path 56 can be calculated based on the reference signal charge amount Sig and the transfer residual charge amount Emp2. The transfer efficiency measurement unit 200 may calculate the horizontal transfer efficiency HTR11 using, for example, an equation consisting of HTR11 = (Sig−Emp1) / Sig × 100, and an equation consisting of HTR12 = (Sig−Emp2) / Sig × 100. May be used to calculate the horizontal transfer efficiency HTR12. The horizontal transfer efficiencies HTR11 and HTR12 vary according to the reference signal charge amount Sig as shown in FIG.

  By the way, when the branching unit 54 and the horizontal transfer paths 56 and 58 are driven and controlled in accordance with the reverse branching drive condition in which the horizontal timing signal of the initial driving condition is shifted, the branching part 54 is connected to the horizontal transfer path 58. The first empty pixel Emp1 is sent to the side, and the reference signal pixel Sig and the second empty pixel Emp2 are sent to the horizontal transfer path 56 side.

  Here, the signal charge left in the transfer of the reference signal pixel Sig from the branching unit 54 to the horizontal transfer path 58 enters the first empty pixel Emp1, and the horizontal transfer path 58 horizontally transfers the reference signal pixel Sig. The signal charge left in step 2 enters the second empty pixel Emp2. The total signal charge amount of these empty pixels Emp1 and Emp2, that is, the transfer residual charge amount 234 of the horizontal transfer path 58 left until reaching the output amplifier 62 from the branching section 54 through the horizontal transfer path 58 is shown in FIG. As shown in FIG. 18, it varies according to the reference signal charge amount.

  Thereafter, the output amplifiers 60 and 62 output the output signal 82 including the first empty pixel Emp1 and the output signal 84 including the reference signal pixel Sig and the second empty pixel Emp2, respectively, and the preprocessing unit 22 Stores the digital signals 110 and 112 based on the output signals 82 and 84 in the memory 24.

  Further, the signal processing unit 26 reads out the first empty pixel Emp1, the reference signal pixel Sig, and the second empty pixel Emp2 from the memory 24 through the bus 114 and the signal line 120 as the digital signal 118.

  In the signal processing unit 26, the transfer efficiency measurement unit 200 obtains the transfer residual charge amount 234 of the horizontal transfer path 58 based on the first empty pixel Emp 1 and the second empty pixel Emp 2, and Of the transfer efficiencies, the horizontal transfer efficiency HTR21 related to the transfer from the branching unit 54 to the horizontal transfer path 58 can be calculated based on the reference signal charge amount Sig and the transfer residual charge amount Emp1, and in the horizontal transfer path 58 The horizontal transfer efficiency HTR22 related to the transfer to the electrodes OG and FD can be calculated based on the reference signal charge amount Sig and the transfer residual charge amount Emp2. The transfer efficiency measurement unit 200 may calculate the horizontal transfer efficiency HTR21 using, for example, an equation consisting of HTR21 = (Sig−Emp1) / Sig × 100, and an equation consisting of HTR22 = (Sig−Emp2) / Sig × 100. The horizontal transfer efficiency HTR22 may be calculated using As shown in FIG. 19, the horizontal transfer efficiencies HTR 21 and 22 change according to the reference signal charge amount Sig.

  The transfer efficiency measurement unit 200 measures one or both of the horizontal transfer efficiencies HTR11 and HTR12, measures one or both of the horizontal transfer efficiencies HTR21 and HTR22, and sends the measurement result to the horizontal transfer paths 56 and 58. It can be used when determining the horizontal transfer efficiency. In this embodiment, in particular, the horizontal transfer efficiency determination is performed based on the residual amount of signal charge left from the R pixel and the B pixel to the G pixel in the branch unit 54, and the residual transfer amount of signal charge caused by the branch unit 54 That is, it is preferable to measure only the horizontal transfer efficiencies HTR11 and HTR21 and use them for the horizontal transfer efficiency determination.

  The transfer efficiency measuring unit 200 of this embodiment can determine which transfer efficiency of the horizontal transfer paths 56 and 58 is better by comparing the horizontal transfer efficiencies HTR11 and HTR21. At this time, the transfer efficiency measurement unit 200 may compare the horizontal transfer efficiencies HTR11 and HTR21 corresponding to a certain reference signal charge amount, and a plurality of horizontal transfer efficiencies HTR11 corresponding to a plurality of reference signal charge amounts. Each evaluation value may be calculated from HTR21 and compared.

  This apparatus 10 measures a transfer efficiency by photographing a predetermined subject in advance, and in this embodiment, a plurality of different subjects are photographed to obtain a plurality of reference signal charge amounts and remaining amounts. Then, the transfer efficiency measurement unit 200 may calculate and compare and determine the horizontal transfer efficiencies HTR11 and HTR21 at a plurality of points.

  Further, in this embodiment, the horizontal transfer path 50 is formed by repeating horizontal pixel mixing in the horizontal transfer path 50 in order to repeatedly create a group 220 in which two or more empty pixels Emp1 and Emp2 are followed by the pixel Sig of the reference signal. The group 220 including the reference signal pixel Sig and the three empty pixels Emp1, Emp2, and Emp3 can be created by driving in the horizontal 8-pixel mixing method.

  Next, in the solid-state imaging device 10 of this embodiment, the operation of driving the horizontal transfer path 50 by the horizontal 8-pixel mixing method is described with reference to the timing chart of FIG. 20 and the potential transition diagrams of FIGS. 21, 22 and 23. While explaining.

  In the potential transition diagrams of FIGS. 21, 22 and 23, the transfer elements HS4, HS1, HS2, HS3, HS2, HS1, HS4, HS3 and HS4 are transferred from the end contacting the branching portion 54 to the other end. The potential potential of the horizontal transfer path 50 formed in that order and the signal charge to be held are shown. The signal charge of each transfer element is transferred toward the left, that is, transferred to the forward transfer element.

  In the horizontal transfer path 50 of the present embodiment, horizontal 8 pixel mixing is executed in the horizontal blanking period, and the signal charges of the group 220 consisting of the transfer elements HS1, HS2, HS3, HS2, HS1, HS4, HS3 and HS4 are mixed. Is done. As shown in FIG. 20 (A), the signal charge is transferred to the horizontal transfer path 50 in accordance with the drive signal φLM supplied to the line memory LM, and as shown in FIGS. 20 (B) to (E), the HS driver The signal charges in the horizontal transfer path 50 are mixed with pixels by being driven and controlled by horizontal serial drive signals 74 such as drive signals φHS1, φHS2, φHS3, and φHS4 supplied from 96.

  First, when the drive signal φLM shown in FIG. 20A becomes level “H” at time t302, the drive signals φHS1 to φHS4 shown in FIGS. 20B to 20E are all at level “H”. The signal charge is transferred from the line memory LM to a packet formed immediately below each electrode of the transfer elements HS1 to HS4 of the horizontal transfer path 50. As shown in FIG. 21A, the potential potential of each transfer element HS1 to HS4 in the state at time t302 is set to the reference level 300.

  Next, when the drive signals φHS2 and φHS4 of level “L” are supplied to the transfer elements HS2 and HS4 at time t304, as shown in FIG. 21 (B), the potential potential is high in the transfer elements HS2 and HS4. Thus, the signal charge is transferred to the forward transfer element HS1 or HS3.

  Further, as shown in FIG. 21C, at time t306, the drive signal φHS4 of level “H” is supplied to the transfer element HS4, and the potential potential returns to the reference level 300.

  Next, as shown in FIG. 22D, when the drive signal φHS3 of level “L” is supplied to the transfer element HS3 at time t308, the potential potential becomes high in the transfer element HS3, and the forward is the transfer element. In the case of HS2, since the potential potential is the same level, the signal charge of the transfer element HS3 is retained, but when the front is the transfer element HS4 having a low potential potential, the signal charge of the transfer element HS3 is Transferred.

  Further, as shown in FIG. 22 (E), at time 310, the drive signal φHS4 of level “L” is supplied to the transfer element HS4, the potential potential becomes high, and the signal charge to be held is transferred to the forward transfer element HS1. Forward.

  Thereafter, as shown in FIG. 22 (F), at time t312, the driving signal φHS1 of level “L” is supplied to the transfer element HS1 to increase the potential potential, and the driving signal φHS2 of level “H” is transferred to the transfer element. Supplyed to HS2, the potential potential returns to the reference level 300. Here, the signal charge is transferred from the transfer element HS1 having a high potential potential to the transfer element HS2 having a low potential potential ahead. Further, the signal charge is transferred from the transfer element HS3 having the lower potential potential to the transfer element HS3 having the higher potential potential.

  Next, as shown in FIG. 23 (G), at time t314, the drive signal φHS2 at the level “L” is supplied to the transfer element HS2 to increase the potential potential, and the drive signal φHS3 at the level “H” is transferred to the transfer element Supplied to HS3, the potential potential returns to the reference level 300. Here, the signal charge is transferred from the transfer element HS2 having a high potential potential to the transfer element HS3 having a low potential potential in front.

  Further, as shown in FIG. 23 (H), at time t316, the drive signal φHS2 of level “H” is supplied to the transfer element HS2 to increase the potential potential, and the drive signal φHS3 of level “L” is transferred to the transfer element HS3. And the potential potential returns to the reference level 300. Here, the signal charge is transferred from the transfer element HS3 having a high potential potential to the transfer element HS2 having a low potential potential ahead.

  Then, as shown in FIG. 23 (I), at time t318, the drive signal φHS1 at the level “H” is supplied to the transfer element HS1 to increase the potential potential, and the drive signal φHS2 at the level “L” is transferred to the transfer element Supplyed to HS2, the potential potential returns to the reference level 300. Here, the signal charge is transferred from the transfer element HS2 having a high potential potential to the transfer element HS1 having a low potential potential ahead.

  In this way, the signal charges of the group 220 consisting of the transfer elements HS1, HS2, HS3, HS2, HS1, HS4, HS3, and HS4 are transferred to the foremost transfer element HS1 and mixed in eight horizontal pixels.

  Further, as shown in FIG. 25, the preprocessing unit 22 includes a G pixel processing unit 352 suitable for processing of G pixels and an RB pixel processing unit 354 suitable for processing of R pixels and B pixels. In this case, of the electrical signals 82 and 84 supplied from the imaging unit 14, the G pixel electrical signal is input to the G pixel processing unit 352, and the RB pixel electrical signal is input to the RB pixel processing unit 354. There is a need to.

  In the present embodiment, the imaging unit 14 connects the output units 362 and 364 to the output amplifiers 60 and 62, respectively, and connects the junctions 372 and 374 to the connection line 82 that outputs an electrical signal, and the junction to the connection line 84. 376 is connected, and the connection between the coupling units is changed according to the measurement result by the transfer efficiency measurement unit 200.

  For example, the imaging unit 14 performs transfer efficiency measurement in a test (probe test) on a silicon wafer. A good horizontal transfer path among the horizontal transfer paths 56 and 58 is determined based on the result of the transfer efficiency measurement. Here, when the horizontal transfer path 58 is good, as shown in FIG. 25, the output portion 362 and the joint portion 372 are joined, and the output portion 364 and the joint portion 374 may be joined, When the horizontal transfer path 56 is satisfactory, the output part 362 and the joint part 374 may be joined as shown in FIG. 26, and the output part 364 and the joint part 376 may be joined.

  As a result, when the apparatus 10 operates at a high speed drive, the output signal 82 output from the imaging unit 14 always indicates the G pixel and is processed by the G pixel processing unit 352, and the output signal 84 always indicates the R pixel and the B pixel. Therefore, processing switching and connection switching outside the imaging unit 14 can be avoided.

  In the imaging unit 14, the output units 362 and 364, and the junctions 372, 374, and 376 may be formed of bonding pads, and the connections 382 and 384 between the junction and the output unit may be formed of switchable wires. . These wires 382 and 384 need to be formed without crossing each other in order to prevent crosstalk from occurring in the transmitted signal.

  Further, when the apparatus 10 captures a subject having a low color temperature, for example, the signal charge obtained by each light receiving element 46 of the imaging unit 14 is large for the R pixel and small for the B pixel. At this time, in the horizontal transfer path 50, if the signal charge is transferred to the branching unit 54 in the order of R pixel, G1 pixel, B pixel, and G2 pixel, the charge mixture that the front R pixel is left behind and enters the rear G1 pixel The amount is larger than the charge mixing amount between the front B pixel and the rear G2 pixel. This is because, as shown in FIG. 18, the charge mixing amount, that is, the transfer residual charge amount increases as the signal amount increases. Therefore, even if these G1 pixels and G2 pixels have the same color signal, a difference occurs in the signal amount, which affects the completed image as fixed pattern noise.

  According to the solid-state imaging device 10 of the present invention, when the signal charge is output from the branching unit 54 via the horizontal transfer path 56 or 58 by the output amplifier 60 or 62, the R pixel and the B pixel in particular have a transfer efficiency. By outputting the signal through a good horizontal transfer path, it is possible to prevent the remaining of electrification from the R pixel and the B pixel, and to prevent the charge from being mixed into the G pixel.

It is a block diagram which shows one Example of the solid-state imaging device which concerns on this invention. It is a block diagram which shows the Example of the solid-state image sensor of the solid-state imaging device of the Example shown in FIG. It is a figure which shows the arrangement pattern of the light receiving element in the solid-state image sensor of FIG. FIG. 4 is a plan view of the horizontal transfer path in the solid-state imaging device of FIG. 2 as viewed from above, and a cross-sectional view of the horizontal transfer path cut along a fracture line IV-IV. FIG. 3 is a plan view of the horizontal transfer path of the solid-state imaging device of FIG. 2 as viewed from above, and a cross-sectional view of the horizontal transfer path taken along the broken line VII-VII. FIG. 2 is a block diagram illustrating a schematic configuration in the driver of FIG. 1. 5 is a timing chart showing timings of drive signals supplied to the respective electrodes in FIG. 4. It is a figure which shows the change of the potential electric potential formed in the horizontal transfer path shown in FIG. It is a figure which shows the change of the potential electric potential formed in the horizontal transfer path shown in FIG. It is a figure explaining transfer of the signal charge which has a color attribute in the horizontal transfer path in the solid-state image sensor of FIG. 4 is a timing chart showing rearrangement of signal charges in a first field in a horizontal blanking period accompanying horizontal transfer of the solid-state imaging device of FIG. 3. 4 is a timing chart showing rearrangement of signal charges in a second field in a horizontal blanking period accompanying horizontal transfer of the solid-state imaging device in FIG. 3. 3 is a timing chart illustrating an operation procedure of horizontal transfer according to a horizontal timing signal of an initial driving condition in high-speed driving in the solid-state imaging device of FIG. 2. 3 is a timing chart showing an operation procedure of horizontal transfer according to a horizontal timing signal of a reverse branch driving condition during high-speed driving in the solid-state imaging device of FIG. 2. 3 is a timing chart illustrating an operation procedure of horizontal transfer during low-speed driving in the solid-state imaging device of FIG. 2. FIG. 3 is a diagram showing signal charges transferred in accordance with a horizontal timing signal of an initial driving condition when measuring transfer efficiency in the horizontal transfer path in the solid-state imaging device of FIG. 2. FIG. 3 is a diagram showing signal charges transferred in accordance with a horizontal timing signal of a reverse branch driving condition when measuring transfer efficiency in the horizontal transfer path in the solid-state imaging device of FIG. 2. 3 is a graph showing a relationship of a transfer residual charge amount with respect to a reference signal amount of two horizontal transfer paths after branching in the solid-state imaging device of FIG. 2. 3 is a graph illustrating a relationship of transfer efficiency with respect to a reference signal amount of two horizontal transfer paths after branching in the solid-state imaging device of FIG. 2. 3 is a timing chart showing an operation procedure of horizontal pixel mixing by a horizontal transfer path before branching in the solid-state imaging device of FIG. 2. FIG. 3 is a diagram showing a change in potential potential formed in each transfer element by horizontal pixel mixing in a horizontal transfer path before branching in the solid-state imaging element of FIG. 2. FIG. 22 is a diagram illustrating a change in potential potential formed in each transfer element, following FIG. 21. FIG. 23 is a diagram illustrating a change in potential potential formed in each transfer element following FIG. 22. It is a figure which shows the change of the output destination according to transfer efficiency in the horizontal transfer path after the branch in the solid-state image sensor of FIG. It is a figure which shows the change of the output destination according to transfer efficiency in the horizontal transfer path after the branch in the solid-state image sensor of FIG.

Explanation of symbols

10 Solid-state imaging device
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
30 Operation unit
32 Timing signal generator

Claims (30)

A plurality of light receiving elements arranged in row and column directions for photoelectrically converting incident light from the object field into signal charges;
A color filter disposed corresponding to each of the plurality of light receiving elements, color-separating the incident light into a plurality of colors and entering one of the light receiving elements;
Vertical transfer means for vertically transferring the signal charges read from the plurality of light receiving elements;
First horizontal transfer means for receiving the signal charge vertically transferred from the vertical transfer means and horizontally transferring the signal charge;
A branching unit arranged at the output end of the first horizontal transfer unit and distributing the horizontally transferred signal charge to any of a plurality of output destinations;
Second and third horizontal transfer means for receiving the signal charges distributed from the branch means and further horizontally transferring the signal charges;
In a solid-state imaging device using a solid-state imaging device including first and second output means provided at respective output ends of the second and third horizontal transfer means,
The apparatus includes a second horizontal transfer means and a second horizontal transfer means for transferring the signal charges from the branching means through the second and third horizontal transfer means to the first and second output means. Including transfer efficiency measuring means for measuring the transfer efficiency,
The drive start time of the first drive signal for driving the first horizontal transfer means or the second drive signal for driving the second and third horizontal transfer means is determined according to the measurement result by the transfer efficiency measurement means. Instead, the signal charge is transferred by preferentially using one of the second and third horizontal transfer means.   2. The solid-state imaging device according to claim 1, wherein the apparatus preferentially uses a horizontal transfer means that is relatively good among transfer efficiencies of the second and third horizontal transfer means. Solid-state imaging device. The solid-state imaging device according to claim 2, wherein when measuring the transfer efficiency, the device generates a measurement imaging signal by imaging a light source having a constant light amount at the time of factory shipment,
The solid-state imaging device, wherein the transfer efficiency measuring means measures the transfer efficiency using the measurement imaging signal. 4. The solid-state imaging device according to claim 3, wherein when the device measures the transfer efficiency, the vertical transfer unit includes a plurality of the signal charges arranged in one horizontal direction including a predetermined number of groups of the signal charges. To the first horizontal transfer means,
The first horizontal transfer means generates a reference signal pixel by mixing the predetermined number of signal charges for each group in the horizontal blanking period, and loses the charge by the mixing after the reference signal pixel. Forming the group so as to continue two or more empty pixels, and storing the signal charges transferred from the vertical transfer means in the first horizontal transfer means by a horizontal pixel mixing method,
Further, the apparatus horizontally transfers the plurality of signal charges in the first horizontal transfer means to the branch means in response to the first drive signal having the initial drive condition, whereby the first and second signals are transferred. Obtaining the first imaging signal for measurement based on the image signal obtained from the output means,
The apparatus horizontally transfers the plurality of signal charges in the first horizontal transfer means to the branch means in response to a first drive signal having the reverse branch drive condition, whereby the first and first Obtaining the second imaging signal for measurement based on the image signal obtained from the output means of 2,
The solid-state imaging device, wherein the transfer efficiency measuring unit measures the transfer efficiency of the second and third horizontal transfer units based on the first and second measurement imaging signals, respectively. 5. The solid-state imaging device according to claim 4, wherein the transfer efficiency measurement unit is configured to transfer the first empty pixel in the first measurement imaging signal from the branch unit to the second horizontal transfer path. The remaining amount is used, and the second empty pixel is used as the charge remaining amount in the horizontal transfer of the second horizontal transfer path, and the transfer efficiency of the second horizontal transfer path is determined from the reference signal pixel and these charge remaining quantities. And
Further, the first empty pixel in the second measurement image pickup signal is set as a remaining amount when transferred from the branching unit to the third horizontal transfer path, and the second empty pixel is set as the third horizontal transfer path. A solid-state imaging device, wherein transfer efficiency of a third horizontal transfer path is determined from the reference signal pixel and the residual charge amount as a remaining amount at the time of horizontal transfer.   5. The solid-state imaging device according to claim 4, wherein the horizontal pixel mixing method is a horizontal 8-pixel mixing method. The solid-state imaging device according to claim 2, wherein the device drives the solid-state imaging device to output two lines.
The branching means distributes and transfers the signal charges transferred from the first horizontal transfer means alternately to the second and third horizontal transfer paths,
The first and second output means simultaneously output the signal charges transferred from the second and third horizontal transfer paths, respectively.
In addition, when the second horizontal transfer unit is preferentially used according to the measurement result, the apparatus uses the first drive start time in the initial drive condition of the first drive signal as it is, The branching means first transfers the signal charge to a second horizontal transfer means;
Further, when the third horizontal transfer means is used preferentially, the time when the first drive start time is relatively shifted from the drive start time of the second drive signal is the reverse branch of the first drive signal. The solid-state image pickup device is characterized in that the signal charge is first transferred to the third horizontal transfer means by the branching means reversely branching using as the driving start time in the driving conditions.   8. The solid-state imaging device according to claim 7, wherein when the horizontal transfer of the solid-state imaging device is driven at high speed to output two lines, the frequency of the second driving signal is reduced to half of the first driving signal. A solid-state imaging device. The solid-state imaging device according to claim 7, wherein the plurality of colors are three primary colors of red, green, and blue,
The plurality of light receiving elements obtains the incident light indicating any one of the three primary colors of red, green, and blue from the color filter, and photoelectrically converts the incident light into the signal charges of red, green, and blue,
The first horizontal transfer means horizontally transfers the red, green and blue signal charges transferred vertically from the vertical transfer means,
The branching unit transfers the red and blue signal charges to a horizontal transfer unit that is used preferentially among the second and third horizontal transfer units, and transfers the green signal charge to the other horizontal transfer unit. A solid-state imaging device. 10. The solid-state imaging device according to claim 9, wherein one of the first and second output means outputs a green signal based on the green signal charge, and the other is red blue based on the red and blue signal charges. Output signals to the first and second output units, respectively,
The apparatus includes a green input unit that inputs the green signal from the solid-state imaging device, and a red-blue input unit that inputs the red-blue signal,
The first and second output means include first and third junctions connected to the green input unit, and second junctions connected to the red-blue input unit,
When the red and blue signal charges are output from the first output means using the second horizontal transfer means preferentially, the first output section and the second junction section are connected; and When the second output unit and the third junction are connected, and when the red and blue signal charges are output from the second output unit using the third horizontal transfer unit preferentially, A solid-state imaging device, wherein the first output unit and the first joint are connected, and the second output unit and the second joint are connected.   11. The solid-state imaging device according to claim 10, wherein the first and second output units and the first, second, and third joint units are connected without intersecting the connection. apparatus.   The solid-state imaging device according to claim 10, wherein the first and second output units and the first, second, and third bonding units are bonding pads. The solid-state imaging device according to claim 2, wherein the device drives the solid-state imaging device to output one line.
The branching unit transfers the signal charge transferred from the first horizontal transfer unit to only one of the second and third horizontal transfer paths,
The first and second output means output the signal charge only on the side where the signal charge is transferred from the second and third horizontal transfer paths,
When the second horizontal transfer means is preferentially used according to the measurement result, the apparatus uses the initial drive condition of the first drive signal as it is, and the branch means Transfer the signal charge only to the horizontal transfer means,
Further, when the third horizontal transfer means is used preferentially, the phase of the first drive signal is reversed from the initial drive condition, or the phase of the second drive signal is reversed to obtain the reverse branch drive condition. A solid-state imaging device using the driving condition, wherein the branching unit reversely branches and transfers the signal charge only to the third horizontal transfer unit.   14. The solid-state imaging device according to claim 13, wherein the device sets the first and second drive signals to the same frequency when driving horizontal transfer of the solid-state imaging device at a low speed to output one line. A solid-state imaging device.   14. The solid-state imaging device according to claim 13, wherein the device drives the horizontal transfer of the solid-state imaging device to output one line, and the horizontal of the non-priority side of the second and third horizontal transfer means. A solid-state imaging device characterized in that the operation of the output means connected to the transfer means is stopped. The incident light from the object scene is separated into a plurality of colors by a color filter, and the incident light passing through the color filter is photoelectrically converted into a signal charge by a plurality of light receiving elements arranged in the row and column directions. The signal charges read from the plurality of light receiving elements are vertically transferred in a vertical transfer step, and the signal charges vertically transferred from the vertical transfer step are received in a first horizontal transfer step and horizontally transferred. In the branch process arranged at the output end of the first horizontal transfer process, the signal charge horizontally transferred from the first horizontal transfer process is distributed to any of a plurality of output destinations, and is distributed from the branch process. The signal charges are received in the second and third horizontal transfer processes and further transferred horizontally, and the signals are output in the first and second output processes provided at the respective output ends of the second and third horizontal transfer processes. Solid that outputs a signal according to charge A driving method for driving the image element,
The method includes a second horizontal transfer step and a third horizontal transfer step in the transfer from the branching step through the second and third horizontal transfer steps to the first and second output steps. Including a transfer efficiency measurement process for measuring each transfer efficiency,
The drive start time of the first drive signal for driving the first horizontal transfer process or the second drive signal for driving the second and third horizontal transfer processes is determined according to the measurement result of the transfer efficiency measurement process. Alternatively, the signal charge is transferred by preferentially using one of the second and third horizontal transfer steps.   17. The driving method according to claim 16, wherein the method preferentially uses the horizontal transfer step which is relatively better among the transfer efficiencies of the second and third horizontal transfer steps. . The method according to claim 17, wherein when measuring the transfer efficiency, the method generates a measurement imaging signal by imaging a light source having a constant light amount at the time of factory shipment of the solid-state imaging device.
The driving method according to claim 1, wherein the transfer efficiency measurement step measures the transfer efficiency using the measurement imaging signal. 19. The method according to claim 18, wherein when the method measures the transfer efficiency, the vertical transfer step includes a plurality of the signal charges arranged in one horizontal direction formed by repetition of a predetermined number of groups of the signal charges. Transfer to one horizontal transfer process,
In the first horizontal transfer step, a reference signal pixel is generated by mixing the predetermined number of signal charges for each group in a horizontal blanking period, and the charge is lost by the mixing after the reference signal pixel. Forming the group so as to continue two or more empty pixels, and storing the signal charges transferred from the vertical transfer step in a first horizontal transfer step by a horizontal pixel mixing method,
Further, the method horizontally transfers the plurality of signal charges in the first horizontal transfer step to the branching step in accordance with the first drive signal having the initial drive condition, whereby the first and second signals are transferred. Obtaining the first imaging signal for measurement based on the image signal obtained from the output step,
The method also horizontally transfers the plurality of signal charges in the first horizontal transfer step to the branch step in accordance with the first drive signal having the reverse branch drive condition, whereby the first and first Obtaining the second imaging signal for measurement based on the image signal obtained from the output step of 2,
The driving method characterized in that the transfer efficiency measurement step measures the transfer efficiencies of the second and third horizontal transfer steps based on the first and second measurement imaging signals, respectively. 20. The method according to claim 19, wherein the transfer efficiency measurement step includes a charge residual amount when the first empty pixel in the first measurement imaging signal is transferred from the branching step to the second horizontal transfer path. And determining the transfer efficiency of the second horizontal transfer path from the reference signal pixel and these charge residual quantities, with the second empty pixel as the charge residual quantity in the horizontal transfer of the second horizontal transfer path,
In addition, the first empty pixel in the second measurement imaging signal is used as an amount left when transferred from the branching process to the third horizontal transfer path, and the second empty pixel is set as the third horizontal transfer path. A drive method comprising: determining transfer efficiency of a third horizontal transfer path from the reference signal pixel and the residual charge amount as a remaining amount at the time of horizontal transfer.   20. The driving method according to claim 19, wherein the horizontal pixel mixing method is a horizontal 8-pixel mixing method. The method according to claim 17, wherein when the solid-state imaging device is driven to output two lines,
The branching step alternately distributes and transfers the signal charges transferred from the first horizontal transfer step to the second and third horizontal transfer paths,
The first and second output steps simultaneously output the signal charges transferred from the second and third horizontal transfer paths, respectively.
Further, in the method, when the second horizontal transfer process is preferentially used according to the measurement result, the first drive start time in the initial drive condition of the first drive signal is used as it is, The branching process first transfers the signal charge to a second horizontal transfer process;
Further, when the third horizontal transfer process is preferentially used, the time when the first drive start time is relatively shifted from the drive start time of the second drive signal is set to the reverse branch of the first drive signal. The driving method is characterized in that the signal charge is transferred to the third horizontal transfer step first after the branching step is reversely branched by using as the driving start time in the driving conditions.   23. The method according to claim 22, wherein when the horizontal transfer of the solid-state imaging device is driven at a high speed for two-line output, the frequency of the second drive signal is half that of the first drive signal. A driving method characterized by the above. 23. The method of claim 22, wherein the plurality of colors are three primary colors of red, green and blue.
The plurality of light receiving elements obtains the incident light indicating any one of the three primary colors of red, green, and blue from the color filter, and photoelectrically converts the incident light into the signal charges of red, green, and blue,
The first horizontal transfer step horizontally transfers the red, green and blue signal charges transferred vertically from the vertical transfer step,
The branching step transfers the red and blue signal charges to a horizontal transfer step that preferentially uses the second and third horizontal transfer steps, and transfers the green signal charge to the other horizontal transfer step. A driving method characterized by: 25. The method of claim 24, wherein the first and second output steps output a green signal based on the green signal charge, and the other outputs a red-blue signal based on the red and blue signal charges. Output to each of the first and second output units,
The method includes a green input unit that inputs the green signal from the solid-state imaging device, and a red-blue input unit that inputs the red-blue signal.
The first and second output steps include first and third junctions connected to the green input unit, and second junctions connected to the red-blue input unit,
When the red and blue signal charges are output from the first output process using the second horizontal transfer process preferentially, the first output unit and the second junction are connected; and When the second output unit and the third junction are connected, and when the red and blue signal charges are output from the second output step using the third horizontal transfer step preferentially, A driving method comprising: connecting a first output section and a first joint section; and connecting the second output section and a second joint section.   26. The driving method according to claim 25, wherein the first and second output portions and the first, second, and third joint portions are connected without intersecting the connection.   26. The driving method according to claim 25, wherein the first and second output sections and the first, second and third joint sections are bonding pads. The method according to claim 17, wherein when the solid-state imaging device is driven to output one line,
The branching step transfers the signal charge transferred from the first horizontal transfer step only to one of the second and third horizontal transfer paths,
The first and second output steps output the signal charge only on the side where the signal charge is transferred from the second and third horizontal transfer paths,
Further, according to the method, when the second horizontal transfer process is preferentially used according to the measurement result, the initial driving condition of the first drive signal is used as it is, and the branching process is performed in the second step. Transfer the signal charge only to the horizontal transfer process,
Further, when the third horizontal transfer process is used preferentially, the phase of the first drive signal is reversed from the initial drive condition, or the phase of the second drive signal is reversed to obtain the reverse branch drive condition. The driving method is characterized in that, using the driving condition, the branching step is reversed and the signal charges are transferred only to the third horizontal transfer step.   29. The method according to claim 28, wherein when the horizontal transfer of the solid-state imaging device is driven at a low speed to output one line, the first and second drive signals are set to the same frequency. Driving method. 29. The method according to claim 28, wherein when the horizontal transfer of the solid-state imaging device is driven to output one line, the horizontal transfer step on the non-priority side of the second and third horizontal transfer steps. A driving method characterized in that the operation of the output process connected to the power supply is stopped.