Patent Abstract:
A solid-state imaging apparatus including: a pixel section having two-dimensionally arranged pixels each containing a photoelectric conversion device for converting a light signal into a signal electric charge and accumulating the signal electric charge, an amplification means for amplifying and outputting as a pixel signal the signal electric charges accumulated at the photoelectric conversion device, a transfer means for transferring the accumulated signal electric charges to the amplification means, and a reset means for resetting the signal electric charges; a vertical scanning section for outputting a vertical scanning signal to drive/control the pixel section row by row; and a vertical selecting section for generating a row transfer signal in accordance with the vertical scanning signal to drive the transfer means and for generating a row reset signal having a falling edge delayed by a predetermined amount from the row transfer signal to drive the reset means.

Full Description:
This application claims benefit of Japanese Patent Application No. 2008-150052 filed in Japan on Jun. 9, 2008, the contents of which are incorporated by this reference. 
     BACKGROUND OF THE INVENTION 
     The present invention relates to solid-state imaging apparatus, and more particularly relates to the solid-state imaging apparatus in which pixels can be reset at high speed. 
     A fundamental construction and drive method of a prior-art MOS type solid-state imaging apparatus will first be described by way of  FIGS. 1 ,  2 ,  3 ,  4 , and  5 .  FIG. 1  shows a pixel construction used in the MOS solid-state imaging apparatus. What is denoted by a numeral  100  in  FIG. 1  is a unit pixel a plurality of which are two-dimensionally arranged into a matrix to acquire image information. The unit pixel  100  includes: a photodiode  101  for effecting photoelectric conversion; an amplification transistor  104  where a photo-generated electric charge occurring at the photodiode  101  is converted into a voltage and is read out as it is amplified for example by means of a pn junction capacitor or gate capacitor; a transfer transistor  102  for transferring the photo-generated electric charge occurring at the photodiode  101  to a gate terminal of the amplification transistor  104 ; a reset transistor  103  for resetting the gate terminal of the amplification transistor  104  and the photodiode  101 ; and a select transistor  105  for selecting the pixel so as to transmit an output of the amplification transistor  104  to a vertical signal line  110 . 
     Here, all components but the photodiode  101  are shielded from light. 
     What is denoted by a numeral  106  is a pixel power supply line for supplying power to all the pixels in common, which is electrically connected to the drain terminal of the amplification transistor  104  and to the drain terminal of the reset transistor  103 .  107  is a row reset line for resetting pixels corresponding to one row, which is electrically connected respectively to the gate terminal of the reset transistor  103  of the pixels corresponding to one row.  108  is a row transfer line for transferring the photo-generated electric charge of the pixels corresponding to one row to the gate terminal of the amplification transistor  104  of the respective pixel, which is electrically connected respectively to the gate terminal of each transfer transistor  102  of the pixels corresponding to one row.  109  is a row select line for selecting the pixels corresponding to one row, which is electrically connected respectively to the gate terminal of each select transistor  105  of the pixels corresponding to one row. A photoelectric conversion function, a reset function, a memory function, an amplification/read function, a select function are achieved with such pixel construction. 
       FIG. 2  typically represents a fundamental construction of the MOS solid-state imaging apparatus. In  FIG. 2 , a numeral  200  represents a pixel section where unit pixels  100  are two-dimensionally arranged into a matrix that corresponds to pixels P 11  to P 33 . For ease of explanation, the unit pixels  100  in this case are placed side by side into 3 rows by 3 columns.  202  represents a vertical scanning circuit for effecting row selection, which sequentially outputs a vertical scanning signal φ VSR(i) (i=1, 2, 3).  203  represents a vertical selecting section which is to respectively transmit a row select signal φ SE(i) (i=1, 2, 3), a row reset signal φ RS(i) (i=1, 2, 3), and a row transfer signal φ TR(i) (i=1, 2, 3) to the row select line  109 , the row reset line  107 , and the row transfer line  108  of each pixel P 11  to P 33  in accordance with the vertical scanning signal φ VSR(i). While in  FIG. 2 , the lines for transmitting the row select signal φ SE, the row reset signal φ RS, and the row transfer signal φ TR to each row are indicated by one solid line and the outputs of vertical select circuits (MV 1 , MV 2 , MV 3 ) of the vertical selecting section  203  are indicated by one solid line for each row, these in actual setting are respectively provided as a number of lines that are independent from each other. 
       FIG. 3  shows a specific construction of the vertical select circuit (MV 1 , MV 2 , MV 3 ) in the vertical selecting section  203 . Referring to  FIG. 3 ,  202  is the vertical scanning circuit, and φ SE, φ RS, φ TR are the row select signal, row reset signal, and row transfer signal, respectively. A signal φ SE(i) (i=1, 2, 3) taking AND of the vertical scanning signal φ VSR(i) (i=1, 2, 3) outputted from the vertical scanning circuit  202  and the row select signal φ SE is connected to the row select line  109  in the pixel section  200 ; a signal φ RS(i) (i=1, 2, 3) taking AND of the vertical scanning signal φ VSR(i) (i=1, 2, 3) and the row reset signal φ RS is connected to the row reset line  107  in the pixel section  200 ; and a signal φ TR(i) (i=1, 2, 3) taking AND of the vertical scanning signal φ VSR(i) (i=1, 2, 3) and the row transfer signal φ TR is connected to the row transfer line  108  in the pixel section  200 . 
     Referring to  FIG. 2 ,  201  represents a current supply section where current supply ML 1 , ML 2 , ML 3  provided column by column and the vertical signal line  110  as described in  FIG. 1  are respectively connected. A source follower circuit is thereby formed column by column with the amplification transistor  104  of each pixel and the current supply ML 1  to ML 3 . Here the current supply ML 1  to ML 3  has a function for causing a flow of constant bias current. 
     Referring to  FIG. 2 ,  204  represents a column processing circuit section where pixel signals outputted from the above described source follower circuits are respectively subjected to correlation double sampling (CDS) by means of column processing circuit CDS 1 , CDS 2 , CDS 3  provided for each column whereby signal processing is effected for example to remove such offset variance as fixed pattern noise of pixel, and then a result of the signal processing is stored.  205  represents a horizontal scanning circuit for effecting column selection from which horizontal scanning signals φ HSR(j) (j=1, 2, 3) are sequentially outputted.  206  represents a horizontal select switch section where the signal processing result stored at the column processing circuit section  204  is transmitted to the horizontal signal line  207  in accordance with the horizontal scanning signal φ HSR(J) (j=1, 2, 3).  208  represents an amplifier for amplifying and outputting to the outside the signal processing result stored at the column processing circuit  204  which has been transmitted to the horizontal signal line  207 . 
     A drive timing at the time of taking moving picture with thus constructed MOS solid-state imaging apparatus will now be described by way of a timing chart in  FIG. 4 . When the vertical scanning signal of the first row φ VSR( 1 ) is outputted from the vertical scanning circuit  202 , the pixels in the first row are made drivable. More particularly, for the pixels of the first row, the row select signal φ SE may be transmitted to the gate terminal of the select transistor  105  of the first row pixels as the select signal of the first row φ SE( 1 ) through the vertical select circuit MV 1  and the row select line  109 . Further, the row reset signal φ RS may be transmitted to the gate terminal of the reset transistor  103  of the first row pixels as the reset signal of the first row φ RS( 1 ) through the vertical select circuit MV 1  and the row reset line  107 . Furthermore, the row transfer signal φ TR may be transmitted to the gate terminal of the transfer transistor  102  of the first row pixels as the transfer signal of the first row φ TR( 1 ) through the vertical select circuit MV 1  and the row transfer line  108 . 
     An operation in period Tv will first be described. When the vertical scanning signal φ VSR( 1 ) attains “H” level and then the row select signal φ SE( 1 ) attains “H” level, an output of the amplification transistor  104  may be transmitted onto the vertical signal line  110 . In other words, a period for effecting reading of signal and processing of signal is started. Next, when the row reset signal φ RS( 1 ) attains “H” level, the gate terminal of the amplification transistor  104  is reset to the level of a pixel power supply VDD. Next, the row reset signal φ RS( 1 ) is brought to “L” level so that a reset level output outputted from the amplification transistor  104  at this time is sampled at the column processing circuit section  204 . 
     Next, the row transfer signal φ TR( 1 ) is driven to “H” level to transfer photo-generated electric charges accumulated at the photodiode  101  are transferred to the gate terminal of the amplification transistor  104 . The row transfer signal φ TR( 1 ) is then brought to “L” level to sample again at the column processing circuit section  204  a signal level output outputted at this time. Subsequently at the column processing circuit section  204 , a differential processing between the sampled signal level output and reset level output is performed and the signals after the differential processing are stored respectively at the column processing circuits CDS 1 , CDS 2 , and CDS 3 . The row select signal φ SE( 1 ) is then brought to “L” level whereby the period for effecting signal read and signal processing is ended. When transfer of the photo-generated electric charges accumulated at the photodiode  101  to the gate terminal of the amplification transistor  104  is complete, the photodiode  101  is reset and an accumulation of photo-generated electric charge is started at the photodiode  101 . 
     An operation in period Th will next be described. When the horizontal scanning signal φ HSR(j) (j=1, 2, 3) is sequentially outputted from the horizontal scanning circuit  205 , the signals after the differential processing stored at the column processing circuits CDS 1 , CDS 2 , CDS 3  in the column processing circuit section  204  are sequentially read out onto the horizontal signal line  207  respectively through horizontal select switches MH 1 , MH 2 , and MH 3  in the horizontal select switch section  206 . The signals read out onto the horizontal signal line  207  are amplified at the output amplifier  208  and are outputted to the outside. The signal to be outputted to the outside is shown as Vout in  FIG. 4 . At this time, a suitable bias current in accordance with signal band is supplied to the output amplifier section  208 . 
     Signals of the pixels corresponding to one row are read out with the above operation. By sequentially effecting this operation from the first row to the third row, signals of all the pixels in the pixel section  200  can be read out. In particular, the pixel signals of the pixels P 11  to P 33  in the light receiving pixel section  200  are sequentially outputted as Vout from the output amplifier section  208 . The periods of the above constitute 1 frame period Tf which in this description, corresponds to an accumulation period of photo-generated electric charge at the photodiode  101 . 
     A description will next be given with respect to case where a still picture is taken with using the solid-state imaging apparatus shown in  FIG. 2 . In the still picture taking, a mechanical shutter is used to determine an exposure time. In the operation at the time of still picture taking, all pixels are reset (initial reset) in a condition shielded from light by closing the mechanical shutter, and an exposure is subsequently started by opening a first blind of the mechanical shutter. After passage of a desired time, then, light is cut off by closing a second blind of the mechanical shutter so as to end the exposure. 
     After the end of the exposure, a read operation is rendered. 
     In transition to the still picture taking from a moving picture taking for example in a live view mode, since the mechanical shutter is always opened at the time of taking moving picture, the mechanical shutter must be closed once and a time lag in the transition is inevitable with the above described method for determining exposure where mechanical shutter is used. In recent years, there is thus provided a method in which an exposure is started by reset operation (initial reset) of the solid-state imaging apparatus to eliminate the time lag in the transition, and the exposure is ended by a mechanical shutter. This method will be referred to hereinafter as first blind electronic shutter. In the first blind electronic shutter operation, it is necessary to perform an initial reset operation and an operation of the mechanical shutter at the same speed so as to match the exposure time between the upper and lower sides of an image. At this time, since mechanical shutter operates at such a high speed as several ms, the initial reset operation must also be performed at a high speed in several ms. 
       FIG. 5  is a timing chart showing drive timing at the time of still picture taking with using the first blind electronic shutter. When the vertical scanning signal of the first row φ VSR( 1 ) is outputted from the vertical scanning circuit  202 , the first row pixels are made drivable. When the vertical scan signal φ VSR( 1 ) attains “H” level and then the row reset signal φ RS( 1 ) attains “H” level, the reset transistors  103  of the pixels corresponding to one row are turned ON. Next, when the row transfer signal φ TR( 1 ) attains “H” level, the photodiodes  101  of the first row attain the power supply voltage VDD whereby the photodiodes  101  are reset and an exposure is started. The second row and after are treated in like manner. After passage of a desired time, then, the exposure is ended by closing the mechanical shutter and signals are read out. The reading of the signals is similar to the signal read operation described in  FIG. 4 . In the still picture taking, however, since light is cut off at the time of reading, an exposure is not started even after the transferring of photo-generated electric charge is ended. 
     At the time of initial reset in first blind electronic shutter operation, while the initial reset operation is rendered as shown in  FIG. 5  as the reset operation alone is sequentially effected on each row, an initial reset period becomes longer when the number of rows is increased with an increase in the number of pixels; it becomes impossible to meet the mechanical shutter operation. 
     To make the initial reset operation correspond to the mechanical shutter operation, therefore, the vertical selecting operation must be rendered at a high speed. 
     Further, a method has been disclosed in Japanese Patent Application Laid-Open 2005-176105 as the method for performing a high-speed initial reset operation. In the method, a plurality of rows is simultaneously reset and this is repeated to achieve the high-speed initial reset operation. 
     SUMMARY OF THE INVENTION 
     In a first aspect of the invention, there is provided a solid-state imaging apparatus including: a pixel section having two-dimensionally arranged pixels each containing a photoelectric conversion device for converting a light signal into a signal electric charge and accumulating the signal electric charge, an amplification means for amplifying and outputting as a pixel signal the signal electric charges accumulated at the photoelectric conversion device, a transfer means for transferring the accumulated signal electric charges to the amplification means, and a reset means for resetting the signal electric charges; a vertical scanning section for outputting a vertical scanning signal to drive/control the pixel section row by row; and a vertical selecting section for generating a row transfer signal in accordance with the vertical scanning signal to drive the transfer means and for generating a row reset signal having a falling edge delayed by a predetermined amount from the row transfer signal to drive the reset means. 
     In a second aspect of the invention, the row reset signal in the solid-state imaging apparatus according to the first aspect is generated with delaying the whole of the transfer signal. 
     In a third aspect of the invention, the solid-state imaging apparatus according to the first aspect further includes a control section for, in a still image taking to be performed with the step of sequentially outputting the pixel signal row by row after passage of a desired exposure period subsequently to an initial reset operation where reset operation alone is sequentially performed row by row of the pixels in the pixel section, effecting a control so that the row transfer signal and the row reset signal are generated at the time of the initial reset operation. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a circuit diagram showing a general pixel construction to be used in MOS solid-state imaging apparatus. 
         FIG. 2  is a block diagram showing a fundamental construction of MOS solid-state imaging apparatus. 
         FIG. 3  is a circuit diagram showing a specific construction of the vertical select circuit in the MOS solid-state imaging apparatus shown in  FIG. 2 . 
         FIG. 4  is a timing chart for explaining an operation at the time of taking moving picture with the MOS solid-state imaging apparatus shown in  FIGS. 2 and 3 . 
         FIG. 5  is a timing chart for explaining an operation at the time of taking still picture with using a first blind electronic shutter in the MOS solid-state imaging apparatus shown in  FIGS. 2 and 3 . 
         FIG. 6  is a block diagram showing an entire construction of the first embodiment of the solid-state imaging apparatus according to the invention. 
         FIG. 7  is a circuit diagram showing a specific construction of a portion of the vertical select circuit and the pixel in the first embodiment shown in  FIG. 6 . 
         FIG. 8  is a block diagram showing construction of a digital camera using the solid-state imaging apparatus according to the first embodiment shown in  FIGS. 6 and 7 . 
         FIG. 9  is a timing chart for explaining an operation at the time of taking still picture with using a first blind electronic shutter in the digital camera shown in  FIG. 8 . 
         FIG. 10  is a timing chart for explaining a drive operation in a second embodiment. 
         FIG. 11  is a block diagram showing an entire construction of the solid-state imaging apparatus according to a third embodiment. 
         FIG. 12  is a circuit diagram showing a specific construction of the vertical select circuit in the third embodiment shown in  FIG. 11 . 
         FIG. 13  is a timing chart for explaining an operation at the time of taking moving picture in the third embodiment shown in  FIGS. 1 and 12 . 
         FIG. 14  is a timing chart for explaining an operation at the time of taking still picture with using a first blind electronic shutter in the third embodiment. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Some embodiments of the solid-state imaging apparatus according to the invention will be described below with reference to the drawings. 
     (Embodiment 1) 
     A first embodiment of the solid-state imaging apparatus according to the invention will now be described by way of  FIGS. 6 ,  7 ,  8 , and  9 . This embodiment corresponds to the first to third aspects of the invention.  FIG. 6  is a block diagram showing construction of the solid-state imaging apparatus as a whole according to the first embodiment. The solid-state imaging apparatus according to this embodiment has a construction identical to the prior-art example shown in  FIG. 2  but the construction of vertical select circuits MV 10 , MV 20 , MV 30  of the vertical selecting section  203  and that a control section  209  for controlling these is provided. Its description on the whole will be omitted.  FIG. 7  is a circuit diagram showing a specific construction of the vertical select circuit (MV 10 , MV 20 , MV 30 ). Since the pixels used here are identical to those in the prior-art example shown in  FIG. 1 , the pixel construction will not be described. 
     Referring to  FIG. 7 ,  202  is a vertical scanning circuit for sequentially outputting a vertical scanning signal φ VSR(i) (i=1, 2, 3). φ SE, φ RS, φ TR, and φ CTL are a row select signal, a row reset signal, a row transfer signal, and delay circuit control signal for controlling a delay circuit  21 , respectively; these signals are controlled by the control section  209 . A signal φ SE(i) (i=1, 2, 3) taking AND of the vertical scanning signal φ VSR(i) (i=1, 2, 3) outputted from the vertical scanning circuit  202  and the row select signal φ SE is connected to the row select line  109  in the pixel section  200 . A signal φ TR(i) (i=1, 2, 3) taking AND of the vertical scanning signal φ VSR(i) (i=1, 2, 3) and the row transfer signal φ TR is connected to the row transfer line  108  in the pixel section. Further, a signal φ RS(i) (i=1, 2, 3) is generated by taking OR of a signal taking AND of the vertical scanning signal φ VSR(i) (i=1, 2, 3) outputted from the vertical scanning circuit  202  and the row reset signal φ RS or a signal taking AND of the delay circuit control signal φ CTL and the transfer signal of i-th row i φ TR(i) (i=1, 2, 3); the signal φ RS(i) (i=1, 2, 3) is connected to the row reset line  107  in the pixel section  200 . While the delay circuit  21  is shown as constituted of AND circuit and OR circuit, it may also be constructed for example with using switches, delay devices, etc. 
     A construction of digital camera will now be described by way of  FIG. 8  with respect to a case where the solid-state imaging apparatus according to the first embodiment constructed as the above is applied to the digital camera. Referring to  FIG. 8 ,  1  is a lens section for forming object image on a solid-state imaging apparatus  5 . At the lens section  1 , zoom, focus, and aperture are driven and controlled by a lens control apparatus  2 .  3  is a shutter serving as a light-shielding member, which in this case is a focal-plane type shutter mechanism to be used in the so-called single lens reflex camera. The shutter  3  is driven and controlled by a shutter drive apparatus  4 .  5  is the solid-state imaging apparatus having construction as shown in  FIG. 6  where object formed into an image at the lens section  1  is taken in as image signal. 
     Further,  6  is an A/D conversion section for converting signal outputted from an output terminal of the solid-state imaging apparatus  5  into a digital signal; and  9  is an imaging signal processing circuit for rendering various types of processing on the signal outputted from the A/D conversion section  6 . Amplification of image signal, various types of correction on image data, compression of image data, etc. are effected at the imaging signal processing circuit  9 .  7  is a drive circuit for driving and controlling the solid-state imaging apparatus  5 ;  11  is a control apparatus for controlling the digital camera as whole;  8  is a memory section for temporarily storing image data; and  10  is an attachable/detachable recording medium such as of semiconductor memory for recording or reading image data. 
     An operation at the time of taking still picture with using the first blind electronic shutter in the digital camera having the above construction will be described below by way of a timing chart in  FIG. 9 . At the time of initial reset, the row select signal φ SE and the row reset signal φ RS are continuously at “L” level, and the row transfer signal φ TR and the delay circuit control signal φ CTL are continuously at “H” level. When the vertical scanning signal of the first row φ VSR( 1 ) is outputted from the vertical scanning circuit  202 , the pixels of the first row are made drivable. When the vertical scan signal φ VSR( 1 ) attains “H” level, the transfer signal of the first row φ TR( 1 ) becomes a signal like the vertical scanning signal φ VSR( 1 ) because the row transfer signal φ TR is at “H” level. Since the row reset signal φ RS is continuously at “L” level, the signal taking AND of the vertical scanning signal φ VSR( 1 ) and the row reset signal φ RS attains “L” level. 
     Further, since the delay circuit control signal φ CTL is continuously at “H” level, the signal taking AND of the first row transfer signal φ TR( 1 ) and the delay circuit control signal φ CTL is a signal like the first row transfer signal φ TR( 1 ). Accordingly, since the reset signal of the first row φ RS( 1 ) becomes a signal taking OR of its “L” level or the row transfer signal of the first row φ TR( 1 ), the first row reset signal φ RS( 1 ) becomes a signal like the first row transfer signal φ TR( 1 ). The timing of the first row reset signal φ RS( 1 ), however, occurs as it is delayed correspondingly to the fact that it goes through the delay circuit  21  where AND and OR are taken as compared to the first row transfer signal φ TR( 1 ). An accumulation of photo-generated electric charge at the pixels of the first row is started from a point in time when the reset signal of the first row φ RS( 1 ) is changed from “H” level to “L” level. After passage of a desired time, then, the accumulation is ended as the mechanical shutter is closed to cut off an incident light. The second row and after are treated in like manner. 
     A signal read operation at the time of this still picture taking is similar to the signal read operation in the prior-art example described in  FIG. 4 . At the time of taking a still picture, however, an exposure is not started even after the transferring of photo-generated electric charge is ended because light is cut off when the signal is read out. 
     Thus, the solid-state imaging apparatus having the above described construction is used to generate a transfer signal from the vertical scanning signal, and the transfer signal is delayed to generate a reset signal. Since it is thus not necessary to make allowance for timing margin between the signals and since a sequential reset is ended row by row, a high-speed initial reset becomes possible without causing exposure unevenness in image. Accordingly, the solid-state imaging apparatus may be achieved as capable of meeting a high-speed mechanical shutter operation. 
     (Embodiment 2) 
     A second embodiment of the invention will now be described by way of  FIG. 10 . This embodiment also corresponds to the first to third aspects of the invention. 
     The construction of the solid-state imaging apparatus in this embodiment itself is identical to the first embodiment shown in  FIG. 6 . With the present embodiment, the drive in the first embodiment is so adapted that resetting is more securely effected.  FIG. 10  shows a timing chart in the case where a reset time of each row at the time of initial reset is made longer in the solid-state imaging apparatus used in the first embodiment. As shown in  FIG. 10 , when time twice that in the first embodiment shown in  FIG. 9  is provided as the period during which the vertical scanning signal φ VSR is at “H” level, the periods during which the row transfer signal of i-th row φ TR(i) (i=1, 2, 3) and the row reset signal of i-th row φ RS(i) are at “H” level are similarly provided as twice the time shown in  FIG. 9 . 
     In this manner, it is possible to reset more securely by providing a longer period during which the vertical scanning signal φ VSR contributing to the resetting is at “H” level. Further, the interval of reset end timing, i.e. timing for starting exposure between each row is equal to the interval between each row of the timing at which the vertical scanning signal φ VSR attains “L” level. For this reason, a high-speed initial reset becomes possible without causing exposure unevenness in image, and thus it is possible to meet a high-speed mechanical shutter operation. Naturally, the period of “H” level of the vertical scanning signal φ VSR is not limited to the time duration shown in  FIG. 10 . 
     (Embodiment 3) 
     A third embodiment of the invention will now be described by way of  FIGS. 11 ,  12 ,  13 , and  14 . This embodiment also corresponds to the first to third aspects of the invention. The solid-state imaging apparatus according to the third embodiment is constructed so that an operation for taking moving picture can also be effected in addition to the still picture taking in the case where the solid-state imaging apparatus capable of generating a transfer signal from vertical scanning signal and of generating a reset signal by delaying the transfer signal is used in a digital camera.  FIG. 11  shows the construction as a whole of the solid-state imaging apparatus according to the third embodiment. It is different from the first embodiment shown in  FIG. 6  in that the vertical scanning circuit and the vertical selecting section are respectively provided in 2 units, i.e. a first vertical scanning circuit  202 - 1  and a second vertical scanning circuit  202 - 2 , and a first vertical selecting section  203 - 1  and a second vertical selecting section  203 - 2 . The first vertical scanning circuit  202 - 1  and the first vertical selecting section  203 - 1  are identical to those in the prior-art example previously shown in  FIG. 2 , and are to control signals to be used at the time of reading. 
     In the second vertical selecting section  203 - 2  shown in  FIG. 12 , φ RS 2  and φ TR 2  are a row reset signal and a row transfer signal, respectively, which are to control signals used in reset. Signals φ SE, φ RS 1 , φ RS 2 , φ TR 1 , and φ TR 2  inputted to the first and second vertical selecting section  203 - 1 ,  203 - 2  are controlled by a control section  209 . A delay circuit  22  in the second vertical selecting section  203 - 2  has a construction as shown in  FIG. 12  where the delay circuit control signal φ CTL is removed from the delay circuit  21  in the first embodiment shown in  FIG. 7  and a buffer is placed instead of AND circuit. The construction of the delay circuit  22 , however, is not limited to the above construction. 
     As shown in  FIG. 12 , a signal taking OR of reset signals of each row outputted respectively from the first vertical selecting section  203 - 1  and the second vertical selecting section  203 - 2  becomes the row reset signal of i-th row φ RS(i) (i=1, 2, 3), and a signal taking OR of transfer signals of each row respectively outputted from the first vertical selecting section  203 - 1  and the second vertical selecting section  203 - 2  becomes the row transfer signal of i-th row φ TR(i) (i=1, 2, 3). The above described reset signal φ RS(i) (i=1, 2, 3) and the row transfer signal φ TR(i) (i=1, 2, 3) are respectively connected to each row reset signal line  107  and each row transfer signal line  108  in a pixel section  200  consisting of pixels P 11  to P 33 . In  FIG. 11 , while the lines for transmitting the row select signal φ SE( 1 ), φ SE( 2 ), φ SE( 3 ), the row reset signal φ RS( 1 ), φ RS( 2 ), φ RS( 3 ), and the row transfer signal φ TR( 1 ), φ TR( 2 ), φ TR( 3 ) to each row is indicated by one solid line, and outputs of the first and second vertical select circuits (MV 1 - 1 , MV 1 - 2 , MV 1 - 3 , MV 2 - 1 , MV 2 - 2 , MV 2 - 3 ) are indicated by one solid line for each one row, these in actual setting are respectively provided independently from each other. It should be noted that, while the row select signal φ SE( 1 ), φ SE( 2 ), φ SE( 3 ) is not one taking OR of signals from the first and second vertical selecting section but is a signal coming from the first vertical selecting section alone, it is shown in  FIG. 11  in a manner as outputted through OR circuit so as to facilitate illustration. 
       FIG. 12  as described above shows a specific construction of the vertical select circuits (MV 1 - 1 , MV 1 - 2 , MV 1 - 3 , MV 2 - 1 , MV 2 - 2 , MV 2 - 3 ) of the first and second vertical selecting section  203 - 1 ,  203 - 2  in the third embodiment. The construction will now be described in more detail. Referring to  FIG. 12 ,  202 - 1 , and  202 - 2  are a first and a second vertical scanning circuits, and φ SE; φ RS 1 , φ RS 2 ; and φ TR 1 , φ TR 2  are a row select signal, row reset signals, and row transfer signals, respectively. The signals φ RS 1 (i) (i=1, 2, 3) and φ TR 1 (i) (i=1, 2, 3) outputted from the first vertical selecting section  203 - 1  are a signal taking AND of the first vertical scanning signal φ VSR 1 (i) (i=1, 2, 3) from the first vertical scanning circuit  202 - 1  and the row reset signal φ RS 1 , and a signal taking AND of the first vertical scanning signal φ VSR 1 (i) (i=1, 2, 3) and the row transfer signal φ TR 1 , respectively. Further, the signal φ SE(i) (i=1, 2, 3) outputted from the first vertical selecting section  203 - 1  is a signal taking AND of the first vertical scanning signal φ VSR 1 (i) (i=1, 2, 3) and the row select signal φ SE. 
     The signals φ RS 2 (i) (i=1, 2, 3) and φ TR 2 (i) (i=1, 2, 3) outputted from the second vertical selecting section  203 - 2  are a signal taking AND of the second vertical scanning signal φ VSR 2 (i) (i=1, 2, 3) from the second vertical scanning circuit  202 - 2  and the row reset signal φ RS 2 , and a signal taking AND of the second vertical scanning signal φ VSR 2 (i) (i=1, 2, 3) and the row transfer signal φ TR 2 , respectively. 
     The row reset signal φ RS(i) (i=1, 2, 3) to be transmitted to the row reset signal line  107  in the pixel section  200  is obtained as one taking OR of the signal φ RS 1 (i) (i=1, 2, 3) outputted from the first vertical selecting section  203 - 1  or the signal φ RS 2 (i) (i=1, 2, 3) outputted from the second vertical selecting section  203 - 2 . 
     The row transfer signal φ TR(i) (i=1, 2, 3) to be transmitted to the row transfer signal line  108  in the pixel section  200  is obtained as one taking OR of the signal φ TR 1 (i) (i=1, 2, 3) outputted from the first vertical selecting section  203 - 1  or the signal φ TR 2 (i) (i=1, 2, 3) outputted from the second vertical selecting section  203 - 2 . 
     An operation at the time of taking moving picture in the third embodiment will now be described by way of a timing chart shown in  FIG. 13 . While reset operation and read operation are consecutively effected row by row in the taking of moving picture, the reset operation is effected by the second vertical scanning circuit  202 - 2  and the second vertical selecting section  203 - 2  and the read operation is effected by the first vertical scanning circuit  202 - 1  and the first vertical selecting section  203 - 1 . At the time of reset, the row reset signal φ RS 2  is continuously at “L” level and the row transfer signal φ TR 2  is continuously at “H” level. When the second vertical scanning signal of the first row φ VSR 2 ( 1 ) is outputted from the second vertical scanning circuit  202 - 2 , the pixels of the first row are made drivable. When the second vertical scanning signal φ VSR 2 ( 1 ) attains “H” level, the transfer signal of the first row φ TR 2 ( 1 ) becomes a signal like the second vertical scanning signal φ VSR 2 ( 1 ) because the row transfer signal φ TR 2  is at “H” level. Since the row reset signal φ RS 2  is continuously at “L” level, the signal taking AND of the second vertical scanning signal φ VSR 2 ( 1 ) and the row reset signal φ RS 2  attains “L” level. 
     Accordingly, since the reset signal of the first row φ RS 2 ( 1 ) outputted from the second vertical selecting section  203 - 2  becomes a signal taking OR of “L” level or the transfer signal of the first row φ TR 2 ( 1 ) outputted from the second vertical selecting section  203 - 2 , it is a signal like the first row transfer signal φ TR 2 ( 1 ) outputted from the second vertical selecting section  203 - 2 . The timing of the first row reset signal φ RS 2 ( 1 ) outputted from the second vertical selecting section  203 - 2 , however, occurs as it is delayed correspondingly to the fact that it goes through the delay circuit  22  consisting of buffer and OR circuit as compared to the first row transfer signal φ TR 2 ( 1 ) outputted from the second vertical selecting section  203 - 2 . 
     The reset signal of the first row φ RS( 1 ) connected to the row reset line  107  in the pixel  100  is an OR of the reset signal of the first row φ RS 2 ( 1 ) outputted from the second vertical selecting section  203 - 2  or the reset signal of the first row φ RS 1 ( 1 ) outputted from the first vertical selecting section  203 - 1 . Then, at the time of reset, since the first row reset signal φ RS 1 ( 1 ) outputted from the first vertical selecting section  203 - 1  is controlled by the control section  209  so that it is at “L” level, the first row reset signal φ RS( 1 ) connected to the row reset line  107  becomes a signal like the first row reset signal φ RS 2 ( 1 ) outputted from the second vertical selecting section  203 - 2 . An accumulation of photo-generated electric charge is started at the pixels of the first row from a point in time when the first row reset signal φ RS( 1 ) is changed from “H” level to “L” level. The second row and after are treated in like manner. 
     At the time of reading, the first vertical scanning circuit  202 - 1  and the first vertical selecting section  203 - 1  operate similarly to the timings of the prior-art example shown in  FIG. 4 . At this time, the reset signal of the first row φ RS( 1 ) is an OR of the reset signal of the first row φ RS 1 ( 1 ) outputted from the first vertical selecting section  203 - 1  or the reset signal of the first row φ RS 2 ( 1 ) outputted from the second vertical selecting section  203 - 2 . 
     Then, in the read period, since the first row reset signal φ RS 2 ( 1 ) outputted from the second vertical selecting section  203 - 2  is controlled by the control section  209  so that it is at “L” level, the first row reset signal φ RS( 1 ) connected to the row reset line  107  becomes a signal like the first row reset signal φ RS 1 ( 1 ) outputted from the first vertical selecting section  203 - 1 . A reset level output outputted when the row reset signal φ RS 1 ( 1 ) is brought to “L” level is sampled at the column processing circuit section  204 . 
     The transfer signal of the first row φ TR( 1 ) connected to the row transfer line  108  in the pixel  100  is an OR of the transfer signal of the first row φ TR 1 ( 1 ) outputted from the first vertical selecting section  203 - 1  or the transfer signal of the first row φ TR 2 ( 1 ) outputted from the second vertical selecting section  203 - 2 . Then, in the read period, since the first row transfer signal φ TR 2 ( 1 ) outputted from the second vertical selecting section  203 - 2  is controlled by the control circuit  209  so that it is at “L” level, the first row transfer signal φ TR 1  connected to the row transfer line  108  becomes a signal like the first row transfer signal φ TR 1 ( 1 ) outputted from the first vertical selecting section  203 - 1 . At the time of reading, the first row transfer signal φ TR( 1 ) is driven to “H” level to transfer photo-generated electric charges accumulated at the photodiode  101  to the gate terminal of the amplification transistor  104 . The row transfer signal of the first row φ TR( 1 ) is then brought to “L” level so that a read processing is effected by sampling again at the column processing circuit section  204  a signal level output outputted at this time. The second row and after are treated in like manner. It should be noted that an exposure period from the resetting to the reading shown in the timing chart of  FIG. 13  corresponds but otherwise is not limited to one row. 
     An operation at the time of taking still picture with using the first blind electronic shutter will next be described by way of a timing chart shown in  FIG. 14 . At first in the taking of still picture, a reset operation is effected by the second vertical scanning circuit  203 - 2 . At the time of initial reset, the row reset signal φ RS 2  is continuously at “L” level and the row transfer signal φ TR 2  is continuously at “H” level. When the second vertical scanning signal of the first row φ VSR 2 ( 1 ) is outputted from the second vertical scanning circuit  202 - 2 , the pixels of the first row are made drivable. When the second vertical scanning signal φ VSR 2 ( 1 ) attains “H” level, the transfer signal of the first row φ TR 2 ( 1 ) becomes a signal like the second vertical scanning signal φ VSR 2 ( 1 ) because the row transfer signal φ TR 2  is at “H” level. Since the row reset signal φ RS 2  is continuously at “L” level, the signal taking AND of the second vertical scanning signal φ VSR 2 ( 1 ) and the row reset signal φ RS 2  attains “L” level. 
     Accordingly, since the reset signal of the first row φ RS 2 ( 1 ) outputted from the second vertical selecting section  203 - 2  becomes a signal taking OR of “L” level or the transfer signal of the first row φ TR 2 ( 1 ) outputted from the second vertical selecting section  203 - 2 , it becomes a signal like the first row transfer signal φ TR 2 ( 1 ) outputted from the second vertical selecting section  203 - 2 . The timing of the first row reset signal φ RS 2 ( 1 ) outputted from the second vertical selecting section  203 - 2 , however, occurs as it is delayed correspondingly to the fact that it goes through the delay circuit  22  consisting of buffer and OR circuit as compared to the transfer signal of the first row φ TR 2 ( 1 ) outputted from the second vertical selecting section  203 - 2 . 
     The reset signal of the first row φ RS( 1 ) connected to the row reset line  107  in the pixel  100  is an OR taken from the reset signal of the first row φ RS 2 ( 1 ) outputted from the second vertical selecting section  203 - 2  or the reset signal of the first row φ RS 1 ( 1 ) outputted from the first vertical selecting section  203 - 1 . Then, at the time of reset, since the first row reset signal φ RS 1 ( 1 ) outputted from the first vertical selecting section  203 - 1  is controlled by the control section  209  so that it is at “L” level, the first row reset signal φ RS( 1 ) connected to the row reset line  107  becomes a signal like the first row reset signal φ RS 2 ( 1 ) outputted from the second vertical selecting section  203 - 2 . An accumulation of photo-generated electric charge is started at the pixels of the first row from the point in time when the first row reset signal φ RS( 1 ) is changed from “H” level to “L” level. The second row and after are treated in like manner. Subsequently, after passage of a desired time, the exposure is ended by the mechanical shutter. 
     A read operation is then effected by causing the first vertical scanning circuit  203 - 1  alone to operate. At the time of reading, the first vertical scanning circuit  202 - 1  and the first vertical selecting section  203 - 1  operate similarly to the timing in the prior-art example shown in  FIG. 4 . At this time, the reset signal of the first row φ RS( 1 ) is an OR taken from the reset signal of the first row φ RS 1 ( 1 ) outputted from the first vertical selecting section  203 - 1  or the reset signal of the first row φ RS 2 ( 1 ) outputted from the second vertical selecting section  203 - 2 . 
     Then, in the read period, since a control is effected by the control section  209  so that the first row reset signal φ RS 2 ( 1 ) outputted from the second vertical selecting section  203 - 2  attains “L” level, the first row reset signal φ RS( 1 ) connected to the row reset line  107  is obtained as a signal like the first row reset signal φ RS 1 ( 1 ) outputted from the first vertical selecting section  203 - 1 . A reset level output outputted when the row reset signal φ RS 1 ( 1 ) is brought to “L” level is sampled at the column processing circuit section  204 . 
     The transfer signal of the first row φ TR( 1 ) connected to the row transfer line  108  in the pixel  100  is an OR taken from the transfer signal of the first row φ TR 1 ( 1 ) outputted from the first vertical selecting section  203 - 1  or the transfer signal of the first row φ TR 2 ( 1 ) outputted from the second vertical selecting section  203 - 2 . 
     Then, in the read period, since a control is effected by the control section  209  so that the first row transfer signal φ TR 2 ( 1 ) outputted form the second vertical selecting section  203 - 2  attains “L” level, the first row transfer signal φ TR 1 ( 1 ) connected to the row transfer line  108  becomes a signal like the first row transfer signal φ TR 1 ( 1 ) outputted from the first vertical selecting section  203 - 1 . 
     At the time of reading, the first row transfer signal φ TR( 1 ) is driven to “H” level to transfer photo-generated electric charges accumulated at the photodiode  101  to the gate terminal of the amplification transistor  104 . The transfer signal of the first row φ TR( 1 ) is then brought to “L” level so that read processing is effected by sampling again at the column processing circuit section  204  a signal level output outputted at this time. The second row and after are treated in like manner. 
     With the solid-state imaging apparatus according to the third embodiment having circuit construction as shown above in  FIGS. 11 and 12 , the operation shown in the timing charts in  FIGS. 13 and 14  is effected, whereby a high-speed mechanical shutter operation can be met in still picture taking without causing exposure unevenness in image and at the same time with making a high-speed initial reset possible, and taking of moving picture is also made possible. 
     According to the first and second aspects of the invention as has been described by way of the above embodiments, it is not necessary to take timing margin into consideration by generating the row transfer signal and the row reset signal from the vertical scanning signal; and at this time, since the row reset signal is generated with delaying the falling of the row transfer signal, the row reset signal attains “L” level as it is delayed from the row transfer signal so that reset operation is more securely effected. Accordingly, it is possible to achieve a solid-state imaging apparatus where the speed of an initial reset operation in the vertical direction can be increased so as to meet a high-speed mechanical shutter operation. Further, according to the third aspect of the invention, since it is not necessary to take timing margin into consideration similarly to the first and second aspects, a high speed reset operation can be rendered at the time of an initial reset operation in still picture taking.

Technology Classification (CPC): 7