Abstract:
An image sensing device includes a unit pixel including one or more first sub-pixels of a white color and a plurality of second sub-pixels of a color other than the white color in a matrix, a row control block suitable for controlling the first and second sub-pixels to output sequentially first and second pixel signals during one row unit time, and an image process block suitable for processing the first and second pixel signal&#39;s.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     The present application claims priority of Korean Patent Application No. 10-2014-0043322, filed on Apr. 11, 2014, which is incorporated herein by reference in its entirety. 
     BACKGROUND 
     1. Field 
     Exemplary embodiments of the present invention relate to a semiconductor design technology, and more particularly, to an image sensing device. 
     2. Description of the Related Art 
     Image sensing devices capture images using photoreactive semiconductors. Image sensing devices may be divided into those using Charge Coupled Device (CCD) technology and those using Complementary Metal Oxide Semiconductor (CMOS) technology. Image sensing devices using CMOS technology are in wide use since it allows for an analog circuit and a digital control circuit to be realized on a single integrated circuit (IC). 
     SUMMARY 
     Exemplary embodiments of the present invention are directed to an image sensing device that improves dynamic range, sensitivity, and the Signal-to-Noise Ratio (SNR). 
     In accordance with an embodiment of the present invention, an image sensing device includes a unit pixel including one or more first sub-pixels of a white color and a plurality of second sub-pixels of a color other than the white color in a matrix, a row control block suitable for controlling the first and second sub-pixels to sequentially output first and second sub-pixel signals during one row unit time, and an image process block suitable for processing the first and second sub-pixel signals. 
     Herein, the one row unit time may be defined by an equation expressed as 1/frame rate/the total number of rows, wherein the total number of the rows is determined based on the unit pixel. 
     In accordance with another embodiment of the present invention, an image sensing device may include a plurality unit pixels arranged in rows and columns and each including a plurality of sub-pixels in a matrix, wherein one or more first sub-pixels among the sub-pixels correspond to a white color and second sub-pixels other than the first sub-pixels among the sub-pixels correspond to one color other than the white color, a row control block suitable for controlling the first and second sub-pixels to have different exposure times during an exposure section and sequentially output first and second sub-pixel signals, respectively, during a read section, and an image process block suitable for generating image data based on the second sub-pixel signals and compensating for sensitivity and signal-to-noise ratio (SNR) of the image data based on the first sub-pixel signal. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a diagram illustrating a structure of a pixel array included in an image sensing device as a comparative example. 
         FIG. 2  is a block diagram illustrating an image sensing device in accordance with an embodiment of the present invention. 
         FIG. 3  is a diagram illustrating a structure of a pixel array shown in  FIG. 2 . 
         FIG. 4  is a diagram illustrating in detail the pixel array shown in  FIG. 3 . 
         FIG. 5  is a circuit diagram exemplarily illustrating a unit pixel shown in  FIG. 4 . 
         FIGS. 6A and 6B  and  FIGS. 7A and 7B  are timing diagrams illustrating an operation of the image sensing device in accordance with the embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION 
     Exemplary embodiments of the present invention are described below in more detail with reference to the accompanying drawings. The present invention may, however, be embodied in different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure is thorough and complete, and fully convey the scope of the present invention to those skilled in the art. Throughout the disclosure, like reference numerals refer to like parts throughout the various figures and embodiments of the present invention. 
       FIG. 1  is a diagram illustrating a structure of a pixel array included in an image sensing device as a comparative example. 
     Referring to  FIG. 1 , the image sensing device may include a pixel array in which a plurality of unit pixels are arranged in a matrix. For example, the pixel array may be arranged in a Bayer pattern. The Bayer pattern may be formed of repetitive cells each composed of 2 by 2 unit pixels. In each of the cells, unit pixels PX 00  and PX 11  of two green colors Gr and Gb may be disposed to be diagonal to each other, and a unit pixel PX 01  of a red color R and a unit pixel PX 10  of a blue color B may be disposed to be diagonal to each other in the two remaining corners. 
     Each of the unit pixels has a predetermined size Lμm×Lμm, and it is not easy to miniaturize the image sensing device, i.e., the size of the unit pixel, because the sensitivity and the Signal-to-Noise Ratio (SNR) thereof may deteriorate due to the miniaturization. 
       FIG. 2  is a block diagram illustrating an image sensing device in accordance with an embodiment of the present invention.  FIG. 3  is a diagram illustrating a structure of a pixel array shown in  FIG. 2 .  FIG. 4  is a diagram illustrating in detail the pixel array shown in FIG.  3 .  FIG. 5  is a circuit diagram exemplarily illustrating a unit pixel shown in  FIG. 4 . 
     Referring to  FIG. 2 , an image sensing device  100  may include a pixel array  110 , a row control block  120 , a read path block  130 , a plurality of column lines COL 0  to COLn, and an image process block  140 . The pixel array  110  includes a plurality of unit pixels arranged in a matrix. The row control block  120  controls an operation of the pixel array  110  during an exposure section and a read section. The read path block  130  converts a plurality of pixel signals VPX 0  to VPXn outputted from the pixel array  110  to digital signals during the read section. The column lines COL 0  to COLn transmit the plurality of pixel signals VPX 0  to VPXn. The image process block  140  processes a plurality of digital signals ADC&lt;0:n&gt; outputted from the read path block  130 . 
     As shown in  FIG. 3 , the pixel array  110  may include a plurality of unit pixels PX 00  to PXmn arranged in a matrix. For example, the pixel array  110  may be arranged in a Bayer pattern. The Bayer pattern may be formed of repetitive cells each composed of 2 by 2 unit pixels, e.g., PX 00 , PX 01 , PX 10  and PX 11 . In each of the cells, the unit pixels PX 00  and PX 11  of two green colors Gr and Gb may be disposed to be diagonal to each other, and the unit pixel PX 01  of a red color R and a unit pixel PX 10  of a blue color B may be disposed to be diagonal to each other in the two remaining corners. 
     Particularly, each of the unit pixels PX 00  to PXmn may include four sub-pixels which include three sub-pixels corresponding to its original color and one sub-pixel corresponding to a white color. For example, the unit pixel PX 00  of a green color Gr may include first to third sub-pixels GrL, GrM and GrS of the green color and a fourth sub-pixel W of a white color, and the unit pixel PX 11  of a green color Gb may include first to third sub-pixels GbL, GbM and GbS of the green color and a fourth sub-pixel W of a white color. The unit pixel PX 01  of a red color R may include first to third sub-pixels RL, RM and RS of the red color and a fourth sub-pixel W of a white color, and the unit pixel PX 10  of a blue color B may include first to third sub-pixels BL, BM and BS of the blue color and a fourth sub-pixel W of a white color. 
     The pixel array  110  may be controlled on the basis of a row by the row control block  120 . For example, referring to  FIG. 4 , the pixel array  110  may include a plurality of rows ROW 0  to ROWm where respective control signals may be applied. For example, the unit pixels PX 00  to PX 0   n  included in the first row ROW 0  may be controlled in common based on a first selection signal SX 0 , first to fourth transfer signals TX 0 &lt;0:3&gt;, and a first reset signal RX 0 . Also, the unit pixels PX 00  to PX 0   n  may be coupled with the column lines COL 0  to COLn, respectively. Particularly the first to fourth sub-pixels included in one of the unit pixels PX 00  to PX 0   n  may be coupled with a corresponding one of the column lines COL 0  to COLn in common. For example, the first to fourth sub-pixels GrL, GrM, GrS and W included in the unit pixel PX 00  of a green color Gr are coupled with the first column line COL 0  in common. The other rows ROW 1  to ROWm may have the same structure. 
     Subsequently, internal structures and coupling relationships of the unit pixels PX 00  to PX 0   n  are described in detail below. Since the internal structures of the unit pixels PX 00  to PX 0   n  are all the same, the first unit pixel PX 00  of a green color Gr is representatively described hereafter. The first unit pixel PX 00  may have a four-shared sub-pixel structure as shown in  FIG. 5 . In other words, the first unit pixel PX 00  may include four photo-diodes PD_GrL, PD_GrM, PD_GrS and PD_W corresponding to the first to fourth sub-pixels GrL, GrM, GrS and W, which are coupled with a floating diffusion node FD in common through four transfer transistors TrT 0 , TrT 1 , TrT 2  and TrT 3 , respectively. The first unit pixel PX 00  having the aforementioned structure selectively outputs first to fourth sub-pixel signals VPX 0 &lt; 0 &gt;, VPX 0 &lt; 1 &gt;, VPX 0 &lt; 2 &gt; and VPX 0 &lt; 3 &gt; and a first common reset signal VRX 0  based on the first reset signal RX 0 , the first to fourth transfer signals TX 0 &lt;0:3&gt; and the first selection signal SX 0 . 
     Referring back to  FIG. 2 , the row control block  120  may control exposure times of the four sub-pixels included in the unit pixels PX 00  to PXmn, during the expose section. For example, when the first sub-pixel GrL among the four sub-pixels has a first exposure time, the second sub-pixel GrM among the four sub-pixels has a second exposure time which is shorter than the first exposure time, and the third sub-pixel GrS among the four sub-pixels has a third exposure time which is shorter than the second exposure time, and the fourth sub-pixel W among the four sub-pixels has a fourth exposure time which is shorter than the third exposure time, during the exposure section. For another example, the row control block  120  may control the first to third sub-pixels GrL, GrM and GrS among the four sub-pixels included in the unit pixels PX 00  to PXmn to have the same fifth exposure time, and control the fourth sub-pixel W among the four sub-pixels included in the unit pixels PX 00  to PXmn to have a sixth exposure time which is shorter than the fifth exposure time, during the exposure section. 
     The row control block  120  may control read operations of the rows ROW 0  to ROWm every one row unit time during the read section. The one row unit time is a read-out time assigned per a unit pixel, and may be defined by the following Equation 1.
 
1/frame rate/the total number of the rows  [Equation 1]
 
In Equation 1 the total number of the rows may be determined on the basis of the unit pixel. For example, the total number of the rows may be M+1 (refer to  FIG. 4 ).
 
     For example, the row control block  120  may control the unit pixels PX 00  to PX 0   n  included in the first row ROW 0  to perform read-out operations simultaneously during a first row unit time, control the unit pixels PX 10  to PX 1   n  included in the second row ROW 1  to perform read-out operations during a second row unit time, and control the unit pixels included in the other rows ROW 2  to ROWm to perform read-out operations in a like manner. 
     The row control block  120  may control the first to fourth sub-pixel signals VPX#&lt;0:3&gt;, which are output signals of the first to fourth sub-pixels, to be sequentially outputted through the corresponding column line COL# during one row unit time. For example, the row control block  120  may control the first to fourth sub-pixel signals VPX 0 &lt; 0 &gt;, VPX 0 &lt; 1 &gt;, VPX 0 &lt; 2 &gt; and VPX 0 &lt; 3 &gt;, which are output signals of the first to fourth sub-pixels GrL, GrM, GrS and W, to be sequentially outputted through the first column line COL 0  during one row unit time. Otherwise, the row control block  120  may control the first to third sub-pixel signals VPX#&lt;0:2&gt;, which are output signals of the first to third sub-pixels, to be outputted simultaneously through the corresponding column line COL#, and control the fourth sub-pixel signal VPX#&lt; 3 &gt;, which is an output signal of the fourth sub-pixel, to be outputted alone through the corresponding column line COL#, during one row unit time. For example, the row control block  120  may control the first to third sub-pixel signals VPX 0 &lt; 0 &gt;, VPX 0 &lt; 1 &gt; and VPX 0 &lt; 2 &gt;, which are output signals of the first to third sub-pixels GrL, GrM and GrS, to be added up and outputted through the first column line COL 0 , and then control the fourth sub-pixel signal VPX 0 &lt; 3 &gt; to be outputted through the first column line COL 0 , during one row unit time. 
     The read path block  130  may include a plurality of read-out parts ROUT 0  to ROUTn. The read-out part ROUT# may convert the first to fourth sub-pixel signals VPX#&lt;0:3&gt; to the digital signals ADC&lt;#&gt;. For example, the read-out part ROUT# may include a sampling unit for generating a sampling signal by sampling the first to fourth sub-pixel signals VPX#&lt;0:3&gt; in a Correlated-Double Sampling (CDS) scheme, a comparison unit for generating a comparison signal by comparing the sampling signal with a ramp signal, a counting unit for generating a counting signal by counting the comparison signal, and a latch unit for latching the counting signal. 
     The image process block  140  may obtain first to third image data of the same color having different exposure times based on the first to third sub-pixel signals VPX#&lt;0:2&gt;, and obtain a white image data based on the fourth sub-pixel signal VPX#&lt; 3 &gt;. 
     Hereafter, an operation of the image sensing device  100  having the aforementioned structure in accordance with the embodiment of the present invention is described with reference to  FIGS. 6A and 6B . 
     For the simple description in the embodiment of the present invention, an operation corresponding to the first unit pixel PX 00  is representatively described. 
       FIGS. 6A and 6B  are timing diagrams exemplarily illustrating an operation of the image sensing device  100  in accordance with an embodiment of the present invention. 
     First of all, an operation of the image sensing device  100  during an exposure section is described below with reference to  FIG. 6A . 
     Referring to  FIG. 6A , the row control block  120  may control the first sub-pixel GrL among the four sub-pixels included in the first unit pixel PX 00  to have a first exposure time L 1 +L 2 +L 3 +L 4 , and control the second sub-pixel GrM among the four sub-pixels included in the first unit pixel PX 00  to have a second exposure time L 2 +L 3 +L 4 , and control the third sub-pixel GrS among the four sub-pixels included in the first unit pixel PX 00  to have a third exposure time L 3 +L 4 , and control the fourth sub-pixel W among the four sub-pixels included in the first unit pixel PX 00  to have a fourth exposure time L 4 , during the exposure section. This is described in detail below. 
     The first sub-pixel GrL is initialized in response to the first reset signal RX 0  and the first transfer signal TX 0 &lt; 0 &gt; which pulse simultaneously at a predetermined moment. For example, an initialization operation of the first sub-pixel GrL indicates that a first photo-diode PD_GrL is initialized while a charge existing in the first photo-diode PD_GrL is discharged to a power supply voltage VDD_PX terminal through a first transfer transistor TrT 0  and a first reset transistor TrR 0 . The second sub-pixel GrM is initialized in response to the first reset signal RX 0  and the second transfer signal TX 0 &lt; 1 &gt; which pulse simultaneously in a predetermined time L 1  from the initialization operation of the first sub-pixel GrL. An initialization operation of the second sub-pixel GrM is the same as the initialization operation of the first sub-pixel GrL. The third sub-pixel GrS is initialized in response to the first reset signal RX 0  and the third transfer signal TX 0 &lt; 2 &gt; which pulse simultaneously in a predetermined time L 2  from the initialization operation of the second sub-pixel GrM. An initialization operation of the third sub-pixel GrS is the same as the initialization operation of the first sub-pixel GrL. The fourth sub-pixel W is initialized in response to the first reset signal RX 0  and the fourth transfer signal TX 0 &lt; 3 &gt; which pulse simultaneously in a predetermined time L 3  from the initialization operation of the third sub-pixel GrS. An initialization operation of the fourth sub-pixel W is the same as the initialization operation of the first sub-pixel GrL. Meanwhile, the first to fourth sub-pixels GrL, GrM, GrS and W may have the exposure times from their initialization operations to another pulses of the transfer signals TX 0 &lt;0:3&gt;, respectively. Since each of the transfer signals TX 0 &lt;0:3&gt; pulses again during a read section, it is obvious that an actual exposure time includes a time taken from first pulses of the transfer signals TX 0 &lt;0:3&gt; during the exposure section to second pulses of the transfer signals TX 0 &lt;0:3&gt; during the read section. Since an interval between the second pulses of the first to third transfer signals TX 0 &lt;0:3&gt; during the read section is negligibly shorter than an interval between the first pulses of the first and third transfer signals TX 0 &lt;0:3&gt; during the exposure section although not illustrated in  FIG. 7 , an exposure time during the read section may be out of consideration. 
     Next, an operation of the image sensing device  100  during a read section is described below with reference to  FIG. 6B . 
     Referring to  FIG. 6B , the row control block  120  may control the first to fourth sub-pixels GrL, GrM, GrS and W to sequentially output the first to fourth sub-pixel signals VPX 0 &lt; 0 &gt;, VPX 0 &lt; 1 &gt;, VPX 0 &lt; 2 &gt; and VPX 0 &lt; 3 &gt; along with the first common reset signal VRX 0  during the read section. This is described in detail below. 
     The first sub-pixel GrL may sequentially output the first common reset signal VRX 0  and the first sub-pixel signal VPX 0 &lt; 0 &gt; in response to the first reset signal RX 0  and the first transfer signal TX 0 &lt; 0 &gt; which sequentially pulse during a first section A of the read section. The first sub-pixel signal VPX 0 &lt; 0 &gt; is a pixel signal which is generated on the basis of a charge photoelectric-converted by the first photo-diode PD_GrL during the first exposure time L 1 +L 2 +L 3 +L 4 . The second sub-pixel GrM may sequentially output the first common reset signal VRX 0  and the second sub-pixel signal VPX 0 &lt; 1 &gt; in response to the first reset signal RX 0  and the second transfer signal TX 0 &lt; 1 &gt; which sequentially pulses during a second section B of the read section. The second sub-pixel signal VPX 2 &lt; 0 &gt; is a pixel signal which is generated on the basis of a charge photoelectric-converted by the second photo-diode PD_GrM during the second exposure time L 2 +L 3 +L 4 . The third sub-pixel GrS may sequentially output the first common reset signal VRX 0  and the third sub-pixel signal VPX 0 &lt; 2 &gt; in response to the first reset signal RX 0  and the third transfer signal TX 0 &lt; 2 &gt; which sequentially pulses during a third section C of the read section. The third sub-pixel signal VPX 3 &lt; 0 &gt; is a pixel signal which is generated on the basis of a charge photoelectric-converted by the third photo-diode PD_GrS during a third exposure time L 3 +L 4 . The fourth sub-pixel W may sequentially output the first common reset signal VRX 0  and the fourth sub-pixel signal VPX 0 &lt; 3 &gt; in response to the first reset signal RX 0  and the fourth transfer signal TX 0 &lt; 3 &gt; which sequentially pulses during a fourth section D of the read section. The fourth sub-pixel signal VPX 4 &lt; 0 &gt; is a pixel signal which is generated on the basis of a charge photoelectric-converted by the fourth photo-diode PD_W during a fourth exposure time L 4 . 
     The first read-out part ROUT 0  outputs the first digital signals ADC&lt; 0 &gt; on the basis of the first to fourth sub-pixel signals VPX 0 &lt; 0 &gt;, VPX 0 &lt; 1 &gt;, VPX 0 &lt; 2 &gt; and VPX 0 &lt; 3 &gt; which are sequentially inputted with the first common reset signal VRX 0 . 
     For example, the first read-out part ROUT 0  may generate a first sampling signal by sampling the first common reset signal VRX 0  and the first sub-pixel signal VPX 0 &lt; 0 &gt;, which are sequentially inputted during the first section A, in a Correlated-Double Sampling (CDS) scheme, generate a first comparison signal by comparing the first sampling signal with a ramp signal, and generate a first counting signal by digital-counting the first comparison signal. The first read-out part ROUT 0  may output the first counting signal as the first digital signal ADC&lt; 0 &gt;. The first read-out part ROUT 0  may generate a second sampling signal by sampling the first common reset signal VRX 0  and the second sub-pixel signal VPX 0 &lt; 1 &gt;, which are sequentially inputted during the second section B, in the CDS scheme, generate a second comparison signal by comparing the second sampling signal with the ramp signal, and generate a second counting signal by digital-counting the second comparison signal. The first read-out part ROUT 0  may output the second counting signal as the first digital signal ADC&lt; 0 &gt;. The first read-out part ROUT 0  may generate a third sampling signal by sampling the first common reset signal VRX 0  and the third sub-pixel signal VPX 0 &lt; 2 &gt;, which are sequentially inputted during the third section C, in the CDS scheme, generate a third comparison signal by comparing the third sampling signal with the ramp signal, and generate a third counting signal by digital-counting the third comparison signal. The first read-out part ROUT 0  may output the third counting signal as the first digital signal ADC&lt; 0 &gt;. The first read-out part ROUT 0  may generate a fourth sampling signal by sampling the first common reset signal VRX 0  and the fourth sub-pixel signal VPX 0 &lt; 3 &gt;, which are sequentially inputted during the fourth section D, in the CDS scheme, generate a fourth comparison signal by comparing the fourth sampling signal with the ramp signal, and generate a fourth counting signal by digital-counting the fourth comparison signal. The first read-out part ROUT 0  may output the fourth counting signal as the first digital signal ADC&lt; 0 &gt;. In short, the first read-out part ROUT 0  may internally generate the first to fourth counting signals during the first to fourth sections A, B, C and D, and sequentially output the first to fourth counting signals as the first digital signal ADC&lt; 0 &gt; to the image process block  140 . Although it is described as an example that the first read-out part. ROUT 0  sequentially outputs the first to fourth counting signals as the first digital signal ADC&lt; 0 &gt; in the embodiment of the present invention, it does not limit the scope of the present invention, and the first read-out part ROUT 0  may simultaneously output the first to fourth counting signals as the first to fourth digital signals. 
     The image process block  140  may generate first to third image data having different exposure times and simultaneously compensate for the deteriorated sensitivity and SNR based on the first digital signal ADC&lt; 0 &gt;. For example, the image process block  140  may generate the first to third image data corresponding to the first to third counting signals which are sequentially inputted as the first digital signal ADC&lt; 0 &gt;. The first image data has the longest exposure time L 1 +L 2 +L 3 +L 4  among the first to third image data, and the second image data has the medium exposure time L 2 +L 3 +L 4  among the first to third image data, and the third image data has the shortest exposure time L 3 +L 4  among the first to third image data. The image process block  140  may compensate for the deteriorated sensitivity and SNR based on the fourth counting signal which is inputted as the first digital signal ADC&lt; 0 &gt;. The fourth counting signal is a signal which is generated based on the fourth sub-pixel signal VPX 0 &lt; 3 &gt; outputted from the fourth sub-pixel W of a white color, and may be used to improve the sensitivity and SNR. Since the method of compensating for the sensitivity and SNR is widely-known, a detailed description thereon is omitted. 
       FIGS. 7A and 7B  are timing diagrams exemplarily illustrating an operation of the image sensing device  100  in accordance with another embodiment of the present invention. 
     First of all, an operation of the image sensing device  100  during an exposure section is described below with reference to  FIG. 7A . 
     Referring to  FIG. 7A , the row control block  120  may control the first to third sub-pixel GrL, GrM and GrS among the four sub-pixels included in the first unit pixel PX 00  to have a fifth exposure time L 5 +L 6 , and control the fourth sub-pixel W among the four sub-pixels included in the first unit pixel PX 00  to have a sixth exposure time L 6 , during the exposure section. This is described in detail below. 
     The first to third sub-pixels GrL, GrM and GrS may be simultaneously initialized in response to the first reset signal RX 0  and the first to third transfer signals TX 0 &lt;0:2&gt; which pulse simultaneously at a predetermined moment. The fourth sub-pixel W may be initialized in response to the first reset signal RX 0  and the fourth transfer signal TX 0 &lt; 3 &gt; which pulse simultaneously in a predetermined time L 5  from initialization operations of the first to third sub-pixels GrL, GrM and GrS. Initialization operations of the first to fourth sub-pixels GrL, GrM, GrS and W may be the same as the aforementioned initialization operations (refer to  FIG. 6A ). Consequently, the first to third sub-pixels GrL, GrM and GrS may have the fifth exposure time L 5 +L 6 , and the fourth sub-pixel W may have the sixth exposure time L 6 . In the fifth exposure time L 5 +L 6  and the sixth exposure time L 6 , an exposure time during a read section is out of consideration. 
     Next, an operation of the image sensing device  100  during a read section is described below with reference to  FIG. 7B . 
     Referring to  FIG. 7B , the first unit pixel PX 00  may output the first common reset signal VRX 0  in response to the first reset signal RX 0  which pulses first during a fifth section E of the read section, and output a first combination sub-pixel signal VPX 0 &lt; 4 &gt; in response to the first to third transfer signals TX 0 &lt;0:2&gt; which pulse later than the first reset signal RX 0  during the fifth section E of the read section. The first combination sub-pixel signal VPX 0 &lt; 4 &gt; may be a pixel signal which is generated from a combination of the charges that are obtained from the photoelectric conversion of the first to third photo-diodes PD_GrL, PD_GrM and PD_GrS during the fifth exposure time L 5 +L 6 . 
     The first unit pixel PX 00  may output the first common reset signal VRX 0  in response to the first reset signal RX 0  which pulses first during a sixth section F of the read section, and output a first individual sub-pixel signal VPX 0 &lt; 5 &gt; in response to the fourth transfer signal TX 0 &lt; 3 &gt; which pulses later than the first reset signal RX 0  during the sixth section F of the read section. The first individual sub-pixel signal VPX 0 &lt; 5 &gt; may be a pixel signal which is individually generated based on the charges obtained from the photoelectric conversion of the fourth photo-diode PD_W during the sixth exposure time L 6 . 
     The first read-out part ROUT 0  may generate a first sampling signal by sampling the first common reset signal VRX 0  and the first combination sub-pixel signal VPX 0 &lt; 4 &gt;, which are sequentially inputted during the fifth section E, in a Correlated-Double Sampling (CDS) scheme, generate a first comparison signal by comparing the first sampling signal with a ramp signal, and generate a first counting signal by digital-counting the first comparison signal. The first read-out part ROUT 0  may output the first counting signal as the first digital signal ADC&lt; 0 &gt;. The first read-out part ROUT 0  may generate a second sampling signal by sampling the first common reset signal VRX 0  and the first individual sub-pixel signal VPX 0 &lt; 5 &gt;, which are sequentially inputted during the sixth section F, in the CDS scheme, generate a second comparison signal by comparing the second sampling signal with the ramp signal, and generate a second counting signal by digital-counting the second comparison signal. The first read-out part ROUT 0  may output the second counting signal as the first digital signal ADC&lt; 0 &gt;. In short, the first read-out part ROUT 0  may internally generate the first and second counting signals during the fifth and sixth sections E and F, and sequentially output the first and second counting signals as the first digital signal ADC&lt; 0 &gt; to the image process block  140 . Although it is described as an example that the first read-out part ROUT 0  sequentially outputs the first and second counting signals as the first digital signal ADC&lt; 0 &gt; in the embodiment of the present invention, it does not limit the scope of the present invention, and the first read-out part ROUT 0  may simultaneously output the first and second counting signals as the first and second digital signals. 
     The image process block  140  may compensate for the deteriorated sensitivity and SNR based on the first digital signal ADC&lt; 0 &gt;. For example, the image process block  140  may generate a first image data compensated for the sensitivity and SNR based on the first counting signal which is inputted as the first digital signal ADC&lt; 0 &gt;. As described above, the first counting signal is generated based on the first combination sub-pixel signal VPX 0 &lt; 4 &gt;. Since the first combination sub-pixel signal VPX 0 &lt; 4 &gt; is the same as a signal where the first to third sub-pixel signals outputted from the first to third sub-pixels GrL, GrM and GrS are combined, the first combination sub-pixel signal VPX 0 &lt; 4 &gt; may have the sensitivity and SNR improved as compared with one sub-pixel signal. Also, the image process block  140  may additionally compensate for the sensitivity and SNR based on the second counting signal inputted as the first digital signal ADC&lt; 0 &gt;. The second counting signal is a signal which is generated based on the first individual sub-pixel signal VPX 0 &lt; 5 &gt; outputted from the fourth sub-pixel W of a white color, and may be used to improve the sensitivity and SNR. Since the method of compensating for the sensitivity and SNR is widely-know, a detailed description thereon is omitted. 
     In accordance with the embodiments of the present invention, it is advantageous in that the image sensing device may compensate for the sensitivity and SNR deteriorating due to a sub-pixel of a small size. Also, it is advantageous in that the image sensing device may improve the dynamic range as image data having different exposure times is obtained. 
     In accordance with the embodiments of the present invention, the image sensing device may improve the dynamic range as image data having different exposure times per frame is obtained. Also, the image sensing device may compensate for the sensitivity and SNR deteriorating due to a sub-pixel of a small size based on a pixel signal outputted from a sub-pixel of a white color. Therefore, motion artifacts occurring in moving images may be minimized, and image degradation may be improved. 
     While the present invention has been described with respect to the specific embodiments, it is noted that the embodiments of the present invention are not restrictive but descriptive. Further, it is noted that the present invention may be achieved in various ways through substitution, change, and modification, by those skilled in the art without departing from the scope of the present invention as defined by the following claims.