JP3868466B2 - Solid-state imaging device, camera provided with the same, and driving method of solid-state imaging device - Google Patents

Description

  The present invention relates to a camera such as a video movie camera and a solid-state imaging device used therefor, and more particularly to a solid-state imaging device capable of high-speed shooting and a camera equipped with such a solid-state imaging device.

  In recent years, video movie cameras using a solid-state image sensor have become widespread, and further higher image quality and higher functionality have been demanded. In particular, it is desired to realize high-speed shooting such as 3 × speed or 6 × speed without degrading image quality. Note that high-speed imaging means that, for example, in the case of triple speed, the operation of outputting the signal charge read from the photoelectric conversion element as an image signal from the solid-state imaging device is performed three cycles in one frame period.

  Here, a conventional technique for realizing high-speed shooting will be described by taking a conventional solid-state imaging device of an all-pixel sequential readout system configured by 768 pixels in the horizontal direction and 480 pixels in the vertical direction as an example. .

  FIG. 22 shows a configuration example of the conventional solid-state imaging device. This solid-state imaging device includes a photoelectric conversion element (photodiode) 91, a vertical transfer unit 92 to which the electrodes V1 to V4 are connected, a horizontal transfer unit 93 to which the electrodes H1 and H2 are connected, and a charge detection unit 94. . As shown in FIG. 22, electrodes V2 and V3 are connected to all rows of photoelectric conversion elements 91, while V1 is connected to one row every three rows, and V4 is connected to the other two rows.

  In this conventional solid-state imaging device, when photographing at normal speed, charges are read from the photoelectric conversion element 91 by applying a pulse of about 15 V to the electrodes V1 and V4. Furthermore, by applying a binary vertical transfer unit drive pulse of 0 V and about −9 V to the electrodes V <b> 1 to V <b> 4, the charge read from the photoelectric conversion element 91 is transferred to the horizontal transfer unit 93.

  On the other hand, when high-speed imaging at 3 × speed is performed, a signal charge is read from only one of every three rows of the photoelectric conversion elements 91 by applying a pulse of about 15 V only to the electrode V1. Thereby, the number of pixels in the vertical direction is reduced to 1/3, and high-speed shooting at 3 × speed is realized.

  FIG. 23 is a drive timing chart during high-speed shooting in the conventional solid-state imaging device. FIG. 24 is a timing chart in which the horizontal blanking period in FIG. 23 is enlarged.

  23 are the scanning line numbers of the television signal. In FIGS. 23 and 24, HD is a horizontal synchronizing signal, and VD is a vertical synchronizing signal. Further, PV1 to PV4 are vertical transfer gate application pulses input to the electrodes V1 to V4 of the vertical transfer unit 92, and PH1 and PH2 are horizontal transfer gates input to the electrodes H1 and H2 of the horizontal transfer unit 93, respectively. Applied pulse.

  As shown in FIG. 23, the above-described conventional solid-state imaging device applies a voltage of about 15 V only to the electrode V1 at the 17th (h17) of the scanning line at the time of high-speed shooting at 3 × speed, and the photoelectric conversion element 91 Signal charges are read from only one row every three rows. In addition, after the 18th (h18) scanning line, a voltage of about −9 V is applied to each of the electrodes V1 to V4 three times during the horizontal blanking period.

  As a result, only one row of signal charges read from the photoelectric conversion element 91 is transferred to the horizontal transfer unit 93. The signal charge transferred to the horizontal transfer unit 93 is transferred to the charge detection unit 94 over one horizontal scanning period. As a result, the conventional solid-state imaging device outputs signal charges corresponding to 768 pixels in the horizontal direction × 160 pixels in the vertical direction, in which the number of pixels in the vertical direction is reduced to 1/3. High-speed shooting has been realized.

  In the conventional driving method as described above, since the length of the horizontal blanking interval is determined, it is necessary to increase the frequency of the vertical transfer gate application pulse as the high-speed imaging magnification increases. However, as the frequency of the vertical transfer gate application pulse increases, the saturation characteristics in the vertical transfer unit 92 deteriorate and the transfer capacity decreases. As a result, the vertical transfer efficiency of the solid-state imaging device deteriorates, and problems such as color mixing and saturation failure occur.

  Therefore, the present invention includes a solid-state imaging device capable of performing high-speed imaging without reducing the vertical transfer efficiency by transferring signal charges without increasing the frequency of the vertical transfer gate application pulse, and the solid-state imaging device. The purpose is to provide a camera.

  In order to achieve the above object, a solid-state imaging device according to the present invention includes a plurality of photoelectric conversion elements arranged in a matrix, a vertical transfer unit that vertically transfers charges read from the photoelectric conversion elements, and the vertical transfer unit. In a solid-state imaging device including a horizontal transfer unit that horizontally transfers the charge transferred from the transfer unit, and a charge detection unit that outputs the charge transferred from the horizontal transfer unit as a video signal, n, m, n / When m is a natural number of 2 or more, among the n rows of photoelectric conversion elements continuous in the row direction, the charge is read n / m times during one vertical scanning period from one row, and 2 or more and m or less are continuously read. The charge read from the photoelectric conversion element in a horizontal scanning period is subjected to n vertical transfers and one horizontal transfer.

  It is preferable that the vertical transfer is performed within the (m−1) horizontal scanning periods, and the horizontal transfer is performed within one horizontal scanning period.

  Reading of the electric charge from the photoelectric conversion element to the vertical transfer unit is performed by applying a first signal, and the vertical transfer of the electric charge is performed by applying a second signal, and n rows continuous in the row direction are performed. A first operation mode in which the first signal is applied to one row of the photoelectric conversion elements, and a second operation mode in which the first signal is applied to each row of the photoelectric conversion elements, It is preferable that the frequency of the second signal in the first operation mode is lower than the frequency of the second signal in the second operation mode.

  In order to achieve the above object, a camera according to the present invention includes at least the solid-state imaging device according to the present invention, an optical system, and a processing circuit that processes a video signal output from the solid-state imaging device. It is.

In order to achieve the above object, a method for driving a solid-state imaging device according to the present invention transfers a plurality of photoelectric conversion elements arranged in a matrix and charges read from the photoelectric conversion elements to a horizontal transfer unit. In a driving method of a solid-state imaging device including a vertical transfer unit, the horizontal transfer unit that transfers the charge to a charge detection unit, and the charge detection unit that outputs the charge as a video signal, n, m, and n / m are Assuming that the natural number is 2 or more, a first step of reading the charge n / m times from one row to one vertical scanning period among the n rows of photoelectric conversion elements continuous in the row direction, and 2 or more and m or less. A second step of performing n vertical transfers and one horizontal transfer of the electric charges read from the photoelectric conversion elements during the horizontal scanning period is achieved. To achieve the solid of the present invention The imaging apparatus includes a plurality of photoelectric conversion elements arranged in a matrix, a vertical transfer unit that vertically transfers charges read from the photoelectric conversion elements in accordance with a charge read signal, and a vertical transfer unit that transfers the charges. In a solid-state imaging device comprising: a horizontal transfer unit that horizontally transfers the received charge in accordance with a horizontal transfer signal; and a charge detection unit that converts the charge horizontally transferred from the horizontal transfer unit into a signal voltage or signal current and outputs the signal voltage m is a natural number of 2 or more, and the charge readout signal is applied to one row every n rows of the photoelectric conversion element (n / m) times in one vertical scanning period, and n vertical transfers and one time are applied. And a signal control unit for controlling the vertical transfer signal and the horizontal transfer signal so that horizontal transfer is performed over a horizontal scanning period of 2 or more and m or less.

  According to this configuration, the charges read from one row every n rows of the photoelectric conversion elements span a horizontal scanning period of 2 or more and m or less, from the vertical transfer unit to the horizontal transfer unit, and further from the horizontal transfer unit. By being transferred to the charge detection unit, high-speed shooting at (n / m) double speed is realized. As a result, as compared with the conventional high-speed imaging technique in which both vertical transfer and horizontal transfer are performed within one horizontal scanning period, time can be afforded for vertical transfer, so that the frequency of the vertical transfer signal can be lowered. As a result, it is possible to provide a solid-state imaging device that realizes high-speed shooting without color mixing or saturation failure without deteriorating vertical transfer efficiency.

  In the solid-state imaging device, the vertical transfer signal is set so that the signal control unit performs the n vertical transfers within (m−1) horizontal scanning periods and performs one horizontal transfer within one horizontal period. Is preferably controlled.

  According to this configuration, the vertical transfer for n rows may be performed within (m−1) horizontal scanning periods, so that the frequency of the vertical transfer signal can be further reduced. As a result, it is possible to provide a solid-state imaging device that realizes high-speed shooting without color mixing or saturation failure without deteriorating the vertical transfer efficiency.

  The solid-state imaging device further includes a first operation mode in which the signal control unit applies the charge readout signal to one row every n rows of the photoelectric conversion elements, and the charge readout to each row of the photoelectric conversion elements. A second operation mode for applying a signal, and the frequency of the vertical transfer signal in the first operation mode is preferably lower than the frequency of the vertical transfer signal in the second operation mode.

  According to this configuration, during high-speed shooting (first operation mode), the frequency of the vertical transfer signal when transferring the charge thinned out to 1 / n in the vertical direction in the vertical direction is set at the normal speed shooting ( By making the frequency lower than the frequency of the vertical transfer signal in the second operation mode), it is possible to improve the transfer efficiency from the vertical transfer unit to the horizontal transfer unit, and to realize high-speed shooting without color mixing or saturation failure An imaging device can be provided.

  In order to achieve the above object, another solid-state imaging device of the present invention converts a plurality of photoelectric conversion elements arranged in a matrix and charges obtained from the photoelectric conversion elements into a signal voltage or a signal current and outputs the signal voltage or signal current. In a solid-state imaging device including a charge detection unit that performs the above operation, n is a natural number of 2 or more, and n times in one vertical scanning period, charges are read from one row for every n rows of the photoelectric conversion elements and transferred to a horizontal transfer unit And a horizontal transfer unit that transfers only a part of one row of charges transferred from the vertical transfer unit to the charge detection unit.

  According to this configuration, only part of the charge for one row transferred from the vertical transfer unit is transferred from the horizontal transfer unit to the charge detection unit, so that all of the charge for one row is transferred to the charge detection unit. Compared to the configuration, the time required for horizontal transfer can be shortened. As a result, there is a time margin for vertical transfer, and there is no need to increase the frequency of the vertical transfer unit drive pulse. As a result, it is possible to provide a solid-state imaging device that realizes high-speed shooting without color mixing or saturation failure without deteriorating transfer efficiency from the vertical transfer unit to the horizontal transfer unit.

  The other solid-state imaging device further includes a charge discharging unit that discharges, from the horizontal transfer unit, charges that are not transferred to the charge detection unit among charges for one row transferred from the vertical transfer unit to the horizontal transfer unit. It is preferable to provide.

  In order to achieve the above-described object, a camera according to the present invention includes a photoelectric conversion unit having a plurality of photoelectric conversion elements arranged in a matrix, and charges read from the photoelectric conversion elements in accordance with a charge read signal. A vertical transfer unit that performs vertical transfer according to a transfer signal, a horizontal transfer unit that horizontally transfers charges transferred from the vertical transfer unit according to a horizontal transfer signal, and a charge that is horizontally transferred from the horizontal transfer unit is converted into a signal voltage or a signal current. And the charge detection signal to be output, and n and m are natural numbers of 2 or more, and the charge readout signal is applied to one row every n rows of the photoelectric conversion elements (n / m) times in one vertical scanning period. And a signal control unit for controlling the vertical transfer signal and the horizontal transfer signal so that n vertical transfers and one horizontal transfer are performed over two or more and m or less horizontal scanning periods. A solid-state imaging device, an optical system that guides light to a photoelectric conversion unit of the solid-state imaging device, and a video signal processing circuit that processes the signal voltage or signal current output from the solid-state imaging device. To do.

  According to this configuration, the charges read from one row for every n rows of photoelectric conversion elements of the solid-state imaging device span a horizontal scanning period of 2 or more and m or less, and further from the vertical transfer unit to the horizontal transfer unit. By transferring from the horizontal transfer unit to the charge detection unit, high-speed shooting at (n / m) double speed is realized. As a result, as compared with the conventional high-speed imaging technique in which both vertical transfer and horizontal transfer are performed within one horizontal scanning period, time can be afforded for vertical transfer, so that the frequency of the vertical transfer signal can be lowered. As a result, it is possible to provide a camera that realizes high-speed shooting without color mixing or saturation failure without deteriorating the vertical transfer efficiency.

  In order to achieve the above object, another camera according to the present invention includes a photoelectric conversion unit having a plurality of photoelectric conversion elements arranged in a matrix and a charge obtained from the photoelectric conversion element as a signal voltage or signal. A charge detection unit that converts the current into an electric current and outputs n, and sets n to a natural number of 2 or more, reads the charge from one row every n rows of the photoelectric conversion element, and transfers it to the horizontal transfer unit n times in one vertical scanning period A solid-state imaging device having a vertical transfer unit, and a horizontal transfer unit that transfers only a part of the charge for one row transferred from the vertical transfer unit to the charge detection unit, and light to the photoelectric conversion unit of the solid-state imaging device And an image signal processing circuit for processing the signal voltage or the signal current output from the solid-state imaging device.

  According to this configuration, in the solid-state imaging device, only part of the charge for one row transferred from the vertical transfer unit is transferred from the horizontal transfer unit to the charge detection unit. Compared with the configuration for transferring to the charge detection unit, the time required for horizontal transfer can be shortened. As a result, there is a time margin for vertical transfer, and there is no need to increase the frequency of the vertical transfer unit drive pulse. As a result, it is possible to provide a camera that realizes high-speed shooting without color mixing or saturation failure without deteriorating the transfer efficiency from the vertical transfer unit to the horizontal transfer unit.

  As described above, according to the present invention, it is not necessary to increase the frequency of the vertical transfer unit drive pulse when transferring the charge read from the photoelectric conversion element from the vertical transfer unit to the horizontal transfer unit. It is possible to provide a solid-state imaging device and a camera that can perform high-speed imaging without degrading the image quality.

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

(Embodiment 1)
As shown in FIG. 1, the solid-state imaging device of the present embodiment includes a photoelectric conversion unit 10 in which a plurality of pixels (not shown) are arranged, and a signal control unit 5, and is controlled by the signal control unit 5. The charge read from the photoelectric conversion unit 10 is transferred to the charge detection unit 4 and converted into a video signal for output.

  As shown in FIG. 2, the pixels of the photoelectric conversion unit 10 are configured by photoelectric conversion elements 1 arranged in a matrix of 768 (columns) in the horizontal direction × 480 (rows) in the vertical direction. As the photoelectric conversion element 1, a photodiode can be used.

  The charge of each photoelectric conversion element 1 is read out to the vertical transfer unit 2 by the signal control unit 5 controlling the vertical transfer unit drive pulse (charge read signal, vertical transfer signal) applied to the electrodes V1 to V4. The data is transferred in the vertical direction toward the horizontal transfer unit 3. The vertical transfer unit 2 can be configured using a CCD (Charge Coupled Device).

  The charges transferred to the horizontal transfer unit 3 are horizontally directed toward the charge detection unit 4 by the signal control unit 5 controlling horizontal transfer unit drive pulses (horizontal transfer signals) applied to the electrodes H1 and H2. Transferred. The horizontal transfer unit 3 can also be configured using a CCD (Charge Coupled Device).

  As shown in FIG. 2, the electrodes V2 and V3 of the vertical transfer unit 2 are connected to all rows of the photoelectric conversion elements 1, but the electrodes V1 are connected to one row of photoelectric conversion elements 1 every six rows. The electrode V4 is connected to the other five rows.

  This solid-state imaging device adopts an all-pixel sequential readout method, and at the time of normal speed imaging, by applying a voltage of about 15 V to the electrodes V1 and V4 at the same time once in one vertical scanning period, The charge is read from the photoelectric conversion element 1. Then, by applying a horizontal transfer unit drive pulse that alternately switches between 0 V and about −9 V to the electrodes V1 to V4, the charges read from the photoelectric conversion element 1 are transferred from the vertical transfer unit 2 to the horizontal transfer unit 3. Is transferred line by line.

  On the other hand, at the time of high-speed shooting at 3 × speed, a voltage of about 15 V is applied only to the electrode V1 three times during one vertical scanning period. Each time this voltage is applied to the electrode V1, the signal charge is read from only one row to the vertical transfer unit 2 every six rows of the photoelectric conversion elements 1, and the number of pixels in the vertical direction is thinned out to 1/6. Then, by performing six vertical transfers and one horizontal transfer in two horizontal scanning periods, one row of charges read from one row of every six rows is sent to the charge detection unit 4, and as a result This realizes high-speed shooting at 3 × speed.

  Here, the operation of the solid-state imaging device during high-speed shooting will be described with reference to FIGS. FIG. 3 is a timing chart showing the relationship between the vertical synchronization signal VD of the solid-state imaging device and the signal PV1 applied to the electrode V1, and FIG. 4 is an enlarged timing chart showing a part of FIG. is there. FIG. 5 is a timing chart showing the horizontal blanking period of FIG. 4 in an enlarged manner.

  H1 to h525 shown at the top of FIG. 4 are scanning line numbers of NTSC television signals. 4 and 5, HD is a horizontal synchronizing signal, and VD is a vertical synchronizing signal. Further, PV1 to PV4 are signals applied to the electrodes V1 to V4 of the vertical transfer unit 2, and PH1 and PH2 are signals applied to the horizontal transfer unit 3.

  This solid-state imaging device applies a voltage of about 15 V to the electrode V1 of the vertical transfer unit 2 on the 17th scanning line (h17), and reads out signal charges from only one row every six rows of the photoelectric conversion elements 1. .

  Then, during the horizontal blanking period of the 18th scanning line (h18), the vertical transfer unit drive pulse of about −9V is applied to the electrodes V1 to V4 of the vertical transfer unit 2 six times, and the 19th scanning line ( h19) In the horizontal blanking period every two horizontal scanning periods thereafter, a vertical transfer section drive pulse of about −9 V is applied to each of the electrodes V1 to V4 six times as shown in FIG. As a result, the signal charges read from one row of the photoelectric conversion elements 1 for every six rows of the photoelectric conversion unit 10 are transferred to the horizontal transfer unit 3 every two horizontal scanning periods.

  Then, as shown in FIG. 5, after the application of the vertical transfer unit driving pulse is completed, the horizontal transfer unit 3 applies the horizontal transfer unit drive pulse to the electrodes H1 and H2 of the horizontal transfer unit 3, thereby The charge is transferred to the charge detection unit 4.

  As a result, the signal charges for one row read out from the photoelectric conversion elements 1 of one row every six rows in the photoelectric conversion unit 10 are transferred between the vertical transfer unit 2 and the horizontal transfer unit 3 every two horizontal scanning periods. To the charge detection unit 4.

  That is, in this embodiment, in the horizontal scanning period of the odd-numbered scanning lines, the charge for one row read out by performing vertical transfer of signal charges from the vertical transfer unit 2 to the horizontal transfer unit 3 six times is obtained. The signal charges for one row transferred to the horizontal transfer unit 3 and transferred to the horizontal transfer unit 3 in the horizontal scanning period of the even-numbered scanning lines are transferred to the charge detection unit 4 over one horizontal scanning period.

  Therefore, from this solid-state imaging device, the number of pixels in the vertical direction is reduced to 1/6, that is, the signal charge of 768 pixels in the horizontal direction × 80 pixels in the vertical direction is three times in one vertical scanning period. By outputting, high-speed shooting at 3 × speed is realized.

  As described above, in the solid-state imaging device according to the present embodiment, vertical transfer and horizontal transfer are performed separately in each of two consecutive horizontal scanning periods, so that time can be afforded for vertical transfer and the vertical transfer unit is driven. Since it is not necessary to increase the pulse frequency, high-speed imaging can be performed without deteriorating the vertical transfer efficiency.

  In the above description, the configuration for realizing 3 × high-speed shooting and the driving method thereof have been described. However, the high-speed shooting at other magnifications such as 2 × and 4 × speeds is similar to the above configuration and driving method. And can be realized.

  That is, when m and n are natural numbers, in order to realize high-speed shooting at (n / m) double speed, charge is transferred from the photoelectric conversion element 1 to the vertical transfer unit 2 at a rate of one row for every n rows. It is only necessary to perform n vertical transfers and one horizontal transfer within the readout and m horizontal scanning periods.

  For example, the above-described configuration and driving method for realizing high-speed shooting at 3 × speed correspond to the case of m = 2 and n = 6.

  Further, when performing high-speed shooting at double speed, for example, m = 3 and n = 6 may be set. That is, the configuration of the vertical transfer unit 2 is the same as the configuration shown in FIG. 2, and the charge is read from the photoelectric conversion element 1 to the vertical transfer unit 2 twice in one vertical scanning period as shown in FIG. A voltage of about 15 V is applied to the electrode V1. That is, as shown in FIG. 7, in the 17th scanning line (h17), a voltage of about 15V is applied to the electrode V1 of the vertical transfer unit 2, and the signal charge is applied from only one row every six rows of the photoelectric conversion elements 1. Is read.

  Then, during the horizontal blanking period of the 18th scanning line (h18), a pulse of about −9 V is applied to the electrodes V1 to V4 of the vertical transfer unit 2 six times, and as shown in FIG. Every two horizontal scanning periods after the scanning line (h19), a vertical transfer section drive pulse of about −9 V is applied to the electrodes V1 to V4 six times, and after the application of the vertical transfer section drive pulse is finished, By applying a horizontal transfer unit drive pulse to the electrodes H 1 and H 2 of the transfer unit 3, the signal charge of the horizontal transfer unit 3 is transferred to the charge detection unit 4. Thereby, the signal charges read from the photoelectric conversion elements 1 in one row every six rows in the photoelectric conversion unit 10 are charged via the vertical transfer unit 2 and the horizontal transfer unit 3 every two horizontal scanning periods. It is transferred to the detection unit 4.

  In addition, when performing high-speed shooting at 4 × speed, for example, m = 2 and n = 8 may be set. In this case, the configuration is such that the electrode V1 of the vertical transfer unit 2 is connected to one row of photoelectric conversion elements 1 every eight rows, and the electrode V4 is connected to the other seven rows, as shown in FIG. In order to read out charges from the photoelectric conversion element 1 to the vertical transfer unit 2 four times in the vertical scanning period, a voltage of about 15 V is applied to the electrode V1. That is, as shown in FIG. 10, in the 17th scanning line (h17), a voltage of about 15V is applied to the electrode V1 of the vertical transfer unit 2, and the signal charge is applied from only one row every eight rows of the photoelectric conversion elements 1. Is read.

  Then, during the horizontal blanking period of the 18th scanning line (h18), a pulse of about −9 V is applied to the electrodes V1 to V4 of the vertical transfer unit 2 six times, and as shown in FIG. For every two horizontal scanning periods after the scanning line (h19), a vertical transfer unit drive pulse of about −9 V is applied to the electrodes V1 to V4 8 times, and after the application of the vertical transfer unit drive pulse is finished, By applying a horizontal transfer unit drive pulse to the electrodes H 1 and H 2 of the transfer unit 3, the signal charge of the horizontal transfer unit 3 is transferred to the charge detection unit 4. Thereby, high-speed shooting at 4 × speed is realized.

  Note that the frequency of the vertical transfer unit drive pulse when transferring charges from the vertical transfer unit 2 to the horizontal transfer unit 3 during high-speed shooting at (n / m) double speed is within m horizontal scanning periods. The vertical transfer unit drive pulse of about −9V can be applied m times while the horizontal transfer unit drive pulse is stopped, and the frequency of the vertical transfer unit drive pulse at the normal speed can be made smaller than the frequency. is there.

  For example, in the case of the 3 × high-speed shooting described above, as can be seen from FIG. 5, the application of the horizontal transfer unit drive pulse is started after the vertical transfer unit drive pulse of about −9 V is applied to the electrodes V1 to V4 six times. There is time to do it. Therefore, as shown in FIG. 12, the frequency of the vertical transfer unit drive pulse of about −9 V can be further reduced. Thereby, the vertical transfer efficiency from the vertical transfer unit 2 to the horizontal transfer unit 3 can be further improved.

  Further, by combining the driving method described in this embodiment with high-speed transfer in the vertical blanking period used for electronic zoom and camera shake correction, higher-speed shooting can be realized.

  In this case, after a charge of about 15 V is applied to the electrode V1 to read out charges from the photoelectric conversion element 1, the charges in 160 rows (area B1 shown in FIG. 13) closer to the horizontal transfer unit 3 are transferred to the horizontal transfer unit. 3 to transfer at high speed.

  The high-speed transfer is a transfer of charges from the vertical transfer unit 2 to the horizontal transfer unit 3 at a high speed of about 300 KHz, and without waiting for completion of transfer of charges from the horizontal transfer unit 3 to the charge detection unit 4. Thus, the transfer from the vertical transfer unit 2 to the horizontal transfer unit 3 is performed. During high-speed transfer, the signal output from the charge detection unit 4 is blanked and is not used as a video signal.

  When the high-speed transfer of the charges for 160 rows in the region B1 is completed, as shown in FIG. 14, the charges for 160 rows in the region B2 are transferred every two horizontal scanning periods by the above-described operation during the high-speed shooting at 3 × speed. By performing the vertical transfer six times, the data is transferred to the horizontal transfer unit 23 at a triple speed. As described above, after the transfer of the charges for 160 rows in the region B2 is completed, the charges for 160 rows in the region B3 are further transferred at high speed. Since 3 × speed is realized only by high-speed transfer by the vertical transfer unit 2, as a result, high-speed shooting at 9 × speed is realized.

(Embodiment 2)
Hereinafter, another embodiment of the present invention will be described with reference to the drawings.

  FIG. 15 shows a schematic configuration of the solid-state imaging device. This solid-state imaging device includes a photoelectric conversion unit 20 in which a plurality of pixels (not shown) arranged in a matrix of 768 (columns) in the horizontal direction × 480 (rows) in the vertical direction, and a signal control unit 25. Under the control of the signal control unit 25, the charge read from the photoelectric conversion unit 20 is transferred to the charge detection unit 24, converted into a video signal, and output.

  As shown in FIG. 16, the pixel of the photoelectric conversion unit 20 includes a photoelectric conversion element 21. A photodiode can be used as the photoelectric conversion element 21.

  The charge of each photoelectric conversion element 21 is read to the vertical transfer unit 22 by the signal control unit 25 controlling the vertical transfer unit drive pulse (charge read signal, vertical transfer signal) applied to the electrodes V1 to V4. The data is transferred in the vertical direction toward the horizontal transfer unit 23. The vertical transfer unit 22 can be configured using a CCD (Charge Coupled Device).

  As will be described later, the charge for one row transferred to the horizontal transfer unit 23 is controlled by the signal control unit 25 by controlling horizontal transfer unit drive pulses (horizontal transfer signals) applied to the electrodes H1 to H6. It is transferred in the horizontal direction toward the detection unit 24 or the drain 27 (charge discharge unit). The horizontal transfer unit 23 can also be configured using a CCD (Charge Coupled Device).

  As shown in FIG. 16, the electrodes V2 and V3 of the vertical transfer unit 22 are connected to all the rows of the photoelectric conversion elements 21, but the electrode V1 is connected to one row of the photoelectric conversion elements 21 every three rows. The electrode V4 is connected to the other two rows.

  As shown in FIG. 15, the photoelectric conversion unit 20 is divided into 2 to 1 in the horizontal direction. That is, the photoelectric conversion unit 20 is divided into a region A1 composed of 512 horizontal conversion elements × 480 vertical conversion elements 21 and a region A2 composed of 256 horizontal conversion elements × 480 vertical conversion elements 21. The

Here, FIG. 17 shows a configuration of the horizontal transfer unit 23 of the present embodiment. FIG. 17 shows a cross section of the horizontal transfer unit 23 cut in parallel to the charge transfer direction. In addition, the forward transfer direction indicated by an arrow in FIG. 17 is a direction in which charges are transferred to the charge detection unit 24 side, and the reverse transfer direction is a direction in which charges are transferred to the drain 27. The horizontal transfer unit 23 has an N-type diffusion layer 42 stacked on a P-type semiconductor substrate 41. This N type diffusion layer 42 becomes a transfer channel of the horizontal transfer unit 23. Further, an N ⁻ type diffusion layer 43 having an impurity concentration lower than that of the N type diffusion layer 42 is formed in the N type diffusion layer 42, and on the N type diffusion layer 42 and the N ⁻ type diffusion layer 43, A four-phase electrode 44 is formed. As shown in FIG. 17, the electrodes 44 formed on the N ⁻ type diffusion layer 43 are the electrodes H1 and H3 of the horizontal transfer portion 23, and the electrodes 44 formed on the N type diffusion layer 42 are H2, H5, H4, and H6.

  The charges generated in the photoelectric conversion element 21 in the region A1 are transferred to the horizontal transfer unit 23 provided with the electrodes H1, H2, H3, and H4, and the charges generated in the photoelectric conversion element 21 in the region A2 are transferred to the electrodes H1, H3. , H5 and H6 are transferred to the horizontal transfer unit 23.

  This solid-state imaging device adopts an all-pixel sequential readout method, and at the time of normal speed imaging, by applying a voltage of about 15 V to the electrodes V1 and V4 at the same time once in one vertical scanning period, The charge is read from the photoelectric conversion element 21. Then, by applying a pulse that alternately switches between 0 V and about −9 V to the electrodes V <b> 1 to V <b> 4, the charges read from the photoelectric conversion element 21 are transferred from the vertical transfer unit 22 to the horizontal transfer unit 23. One line is vertically transferred.

  Then, as shown in FIG. 18 (a), the horizontal transfer section drive pulse is applied so that the electrodes H1 and H4 are in phase with each other and the electrodes H1 and H4 are in reverse phase with the electrodes H2 and H3. By setting H1 and H5 in opposite phases to each other and applying horizontal transfer unit drive pulses in opposite phases to the electrodes H3 and H6 to the electrodes H1 and H5, respectively, one row transferred from the vertical transfer unit 22 to the horizontal transfer unit 23 Are sequentially transferred to the charge detector 24.

  On the other hand, at the time of high-speed shooting, a voltage of about 15 V is applied only to the electrode V1 of the vertical transfer unit 22 to read out charges from one row every three rows of the photoelectric conversion elements 21. Then, by applying a pulse that alternately switches between 0 V and about −9 V to the electrodes V <b> 1 to V <b> 4, the charges read from the photoelectric conversion element 21 are transferred from the vertical transfer unit 22 to the horizontal transfer unit 23. One line is vertically transferred.

  Next, the electrodes H1 to H4 connected to the region A1 of the photoelectric conversion unit 20 in the horizontal transfer unit 23 are arranged such that the electrodes H1 and H4 are in phase with each other as shown in FIG. By applying a horizontal transfer unit driving pulse having a phase opposite to that of the electrodes H2 and H3 to H1 and H4, the signal charge read from the photoelectric conversion element 21 existing in the region A1 in the photoelectric conversion unit 20 is transferred from the horizontal transfer unit 23. It is transferred to the charge detection unit 24 by forward transfer.

  On the other hand, the signal charges read from the photoelectric conversion element 21 existing in the region A2 of the photoelectric conversion unit 20 are applied to the electrodes H1, H3, H5, and H6 connected to the region A2 in the horizontal transfer unit 23. As shown in FIG. 18B, the electrodes H1 and H5 have the same phase as each other, and the electrodes H3 and H6 are present in the region A2 by applying the horizontal transfer unit drive pulse having the opposite phase to the electrodes H1 and H5. The signal charge read from the photoelectric conversion element 21 is discharged from the horizontal transfer unit 23 to the drain 27 by the inversion layer.

  Thereby, at the time of high-speed shooting, only the signal charges read from 512 photoelectric conversion elements 21 existing in the area A1 in one row of the photoelectric conversion units 20, that is, 768 photoelectric conversion elements 21, The data is transferred from the horizontal transfer unit 23 to the charge detection unit 24 and output as a video signal.

  Here, the operation of the solid-state imaging device during high-speed shooting will be described with reference to FIGS. 19 and 20.

  In FIG. 19, h1 to h525 shown in the uppermost row are scanning line numbers of NTSC television signals. HD is a horizontal synchronizing signal, and VD is a vertical synchronizing signal. Furthermore, PV1 to PV4 are signals applied to the electrodes V1 to V4 of the vertical transfer unit 22, and PH1 to PH6 are signals applied to the electrodes H1 to H6 of the horizontal transfer unit 23.

  As shown in FIG. 19, the solid-state imaging device applies a voltage of about 15 V to the electrode V <b> 1 of the vertical transfer unit 22 on the 17th scanning line (h <b> 17), and 1 for every three rows of the photoelectric conversion elements 21. Read signal charge from row only.

  Then, in the horizontal blanking period after the 18th scanning line (h18), as shown in FIG. 20, by applying a pulse of about −9 V three times to the electrodes V1 to V4 of the vertical transfer unit 22, The signal charge read from the photoelectric conversion element 21 is transferred to the horizontal transfer unit 23 for one row.

  Next, by applying a horizontal transfer unit drive pulse to the electrodes H1 to H6 of the horizontal transfer unit 23, the signal charge of the horizontal transfer unit 23 is transferred to the charge detection unit 24. As described above, the horizontal transfer unit driving pulses applied to the electrodes H1, H2, and H6 and the electrodes H3, H4, and H5 are in opposite phases. Thereby, only the signal charge obtained from the area A1 of the photoelectric conversion unit 20, that is, the signal charge for 512 pixels obtained by thinning out 768 pixels per row to 2/3, is transferred from the horizontal transfer unit 23 to the charge detection unit 24. Simultaneously with the transfer, the signal charge obtained from the region A2 is discharged from the drain 27.

  Thereby, from the solid-state imaging device of the present embodiment, the number of pixels in the vertical direction is reduced to 1/3 and the number of pixels in the horizontal direction is reduced to 2/3, that is, equivalent to 512 pixels in the horizontal direction × 160 pixels in the vertical direction. To be output.

  Since the number of pixels horizontally transferred from the horizontal transfer unit 23 to the charge detection unit 24 is 2/3 of one row, the time required for the horizontal transfer is 2/3 at the time of shooting at the normal speed. Since the vertical transfer unit drive pulse is applied while the horizontal transfer unit drive pulse is stopped, the time required for the horizontal transfer is shortened, so that there is a time margin for the vertical transfer. As a result, high-speed shooting at 3 × speed is possible without increasing the frequency of the vertical transfer unit drive pulse.

  As shown in FIG. 21, the solid-state imaging device described in the first or second embodiment is used as the imaging unit 30, and an optical system 31 such as a lens that guides light to the imaging unit 30, and imaging Video movie camera capable of high-speed shooting by providing a video signal processing circuit 32 for processing the video signal obtained by the unit 30, that is, the video signal output from the charge detection unit 4 or 24 of the solid-state imaging device Can be realized.

  The configuration of the photoelectric conversion unit, the number of pixels, the readout method, the high-speed shooting multiple, and the like of the solid-state imaging device described in the above embodiments are merely examples of the embodiment of the present invention, and are not limited thereto. It is not a thing.

1 is a block diagram showing a schematic configuration of a solid-state imaging apparatus according to a first embodiment of the present invention. Explanatory drawing which shows the connection relation between each photoelectric conversion element, a vertical transfer part, and a horizontal transfer part in the solid-state imaging device. Timing chart showing the relationship between the vertical synchronization signal and the signal applied to the electrode V1 of the vertical transfer unit at the time of high-speed shooting at 3 × speed in the solid-state imaging device of the first embodiment. Timing chart showing an enlarged part of FIG. FIG. 4 is a timing chart showing an expanded horizontal blanking period. Timing chart showing the relationship between the vertical synchronization signal and the signal applied to the electrode V1 of the vertical transfer unit at the time of high-speed shooting at double speed in the solid-state imaging device FIG. 6 is a partially enlarged timing chart FIG. 7 is a timing chart showing an expanded horizontal blanking period. Timing chart showing the relationship between the vertical synchronization signal and the signal applied to the electrode V1 of the vertical transfer unit during high-speed shooting at 4 × speed in the solid-state imaging device 9 is an enlarged timing chart showing a part of FIG. Timing chart showing the horizontal blanking period of FIG. Timing chart showing a modification of the vertical transfer unit drive pulses PV1 to PV4 shown in FIG. As a modification of the first embodiment, in order to explain an example in which high-speed transfer in the vertical direction is applied to the solid-state imaging device, an explanatory diagram showing areas (B1 and B3) in which high-speed transfer is performed Timing chart showing each signal in the modified example FIG. 2 is a block diagram showing a schematic configuration of a solid-state imaging apparatus according to Embodiment 2 of the present invention. Explanatory drawing which shows the connection relation of each photoelectric conversion element, the vertical transfer part, and a horizontal transfer part in the solid-state imaging device of the said Embodiment 2. FIG. Explanatory drawing which shows the structure of the horizontal transfer part with which the solid-state imaging device of the said Embodiment 2 is provided. 4 is a timing chart of horizontal transfer unit drive pulses applied to the horizontal transfer unit, (a) is a timing chart of horizontal transfer unit drive pulses applied to the electrodes H1 to H6 in the case of forward transfer, and (b) is reverse rotation. Timing chart of horizontal transfer section drive pulse applied to electrodes H1, H3, H5, and H6 in the case of transmission Timing chart showing respective signals at the time of high-speed shooting at 3 × speed in the solid-state imaging device FIG. 19 is a timing chart showing an enlarged horizontal blanking period. 1 is a block diagram showing a schematic configuration of a camera according to the present invention. Explanatory drawing which shows the structure of the conventional solid-state imaging device Timing chart of each signal at the time of high-speed shooting in the conventional solid-state imaging device FIG. 23 is an enlarged timing chart showing the horizontal blanking period.

Explanation of symbols

1.21 Photoelectric Conversion Element 2.22 Vertical Transfer Unit 3.23 Horizontal Transfer Unit 4.24 Charge Detection Unit 5.25 Signal Control Unit 10.20 Photoelectric Conversion Unit 27 Drain 30 Optical System 31 Imaging Unit 32 Video Signal Processing Circuit 41 P type semiconductor substrate 42 N type diffusion layer 43 N ⁻ type diffusion layer 44 Electrode

Claims (5)

A plurality of photoelectric conversion elements arranged in a matrix, a vertical transfer unit that vertically transfers charges read from the photoelectric conversion elements, a horizontal transfer unit that horizontally transfers the charges transferred from the vertical transfer unit, and the horizontal In a solid-state imaging device including a charge detection unit that outputs the charge transferred from the transfer unit as a video signal,
When n, m, and n / m are natural numbers of 2 or more, the charge is read out n / m times from one row to one vertical scanning period among the n rows of photoelectric conversion elements continuous in the row direction. A solid-state imaging device that performs n vertical transfers and one horizontal transfer on the charges read from the photoelectric conversion elements within a continuous horizontal scanning period of m or less.   2. The solid-state imaging device according to claim 1, wherein the vertical transfer is performed in (m−1) times of the horizontal scanning period, and the horizontal transfer is performed in one time of the horizontal scanning period. Reading the charge from the photoelectric conversion element to the vertical transfer unit is performed by applying a first signal, and the vertical transfer of the charge is performed by applying a second signal,
A first operation mode in which the first signal is applied to one of the n rows of photoelectric conversion elements that are continuous in the row direction; and a second operation in which the first signal is applied to each row of the photoelectric conversion elements. The solid-state imaging device according to claim 2, further comprising: an operation mode, wherein a frequency of the second signal in the first operation mode is lower than a frequency of the second signal in the second operation mode. .   A camera comprising at least the solid-state imaging device according to claim 1, an optical system, and a processing circuit that processes a video signal output from the solid-state imaging device. A plurality of photoelectric conversion elements arranged in a matrix, a vertical transfer unit that transfers charges read from the photoelectric conversion elements to a horizontal transfer unit, the horizontal transfer unit that transfers the charges to a charge detection unit, and the charges In a driving method of a solid-state imaging device including the charge detection unit that outputs as a video signal,
Assuming that n, m, and n / m are natural numbers of 2 or more, a first read out of the charge n / m times from one row to one vertical scanning period among the n rows of photoelectric conversion elements continuous in the row direction. And a second step of performing n vertical transfers and one horizontal transfer of the electric charges read from the photoelectric conversion elements within a horizontal scanning period of 2 or more and m or less. A method for driving a solid-state imaging device.

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