Image sensor and image processing system

Abstract

Disclosed is an image sensor and an image processing system. The image sensor includes: a center pixel group including 2x2 pixels having different colors in a center region of a 6x6 unit pixel group; and first to fourth color pixel groups having the same color as one pixel of the center pixel group, arranged as a unit of 2x4 pixels or 4x2 pixels to have a shape surrounding the center pixel group and having different colors.

Description

[0001] Cross-references to related applications

[0002] This application claims priority to Korean Patent Application No. 10-2021-0194335, filed on December 31, 2021, the disclosure of which is incorporated herein by reference in its entirety. Technical Field

[0003] Various embodiments of this disclosure relate to a data semiconductor circuit, and more specifically, to an image sensor and an image processing system. Background Technology

[0004] The computing paradigm has shifted to ubiquitous computing systems that allow users to access computer systems anytime, anywhere. Consequently, the use of portable electronic devices such as mobile phones, digital cameras, and laptops has been growing rapidly.

[0005] Image sensors, widely used in these electronic devices, capture images by utilizing the light-response properties of semiconductors. Image sensors can be broadly categorized into charge-coupled device (CCD) image sensors and complementary metal-oxide-semiconductor (CMOS) image sensors. Recently, CMOS image sensors have become widely used because they allow both analog and digital control circuitry to be implemented directly on a single integrated circuit (IC). Summary of the Invention

[0006] Various embodiments of this disclosure are directed to image sensors and image processing systems with different colors that may be included in the central area of ​​a 6x6 unit pixel, thereby enabling operation in a 4-sum mode or 8-sum mode in a four-quadrant pattern while using the existing 2x2 driving mode to improve the output readout speed of the image sensor.

[0007] According to one embodiment of this disclosure, an image sensor may include: a central pixel group having at least two different colors and 2x2 pixels disposed in the central area of ​​a 6x6 unit pixel group; and a first color pixel group to a fourth color pixel group, each color pixel group corresponding to a corresponding color, the first color pixel group to the fourth color pixel group being configured as 2x4 pixel or 4x2 pixel units surrounding the central pixel group.

[0008] According to one embodiment of the present disclosure, an image sensor can include a first sub-color pixel group including a plurality of first photodiodes and a first floating diffusion node sharing the plurality of first photodiodes, a second sub-color pixel group including a plurality of second photodiodes and a second floating diffusion node sharing the plurality of second photodiodes, and a dual gain conversion transistor adapted to selectively couple the first floating diffusion node to the second floating diffusion node, wherein the first sub-color pixel group and the second sub-color pixel group have pixels of a same color.

[0009] According to one embodiment of the present disclosure, an image processing system can include a first sub-color pixel group including a plurality of first photodiodes and a first floating diffusion node sharing the plurality of first photodiodes, a second sub-color pixel group including a plurality of second photodiodes and a second floating diffusion node sharing the plurality of second photodiodes, and a dual gain conversion transistor adapted to selectively couple the first floating diffusion node to the second floating diffusion node, wherein the first sub-color pixel group and the second sub-color pixel group have pixels of a same color.

[0010] According to one embodiment, an image sensor can include a center pixel group having at least two sub-pixel groups each corresponding to a different color, and a plurality of boundary pixel groups each corresponding to a respective color, and the plurality of boundary pixel groups are disposed to surround the center pixel group. BRIEF DESCRIPTION OF DRAWINGS

[0011] Figure 1 FIG. 1 is a diagram illustrating a pixel array of a type proposed to be disposed as a 6x6 unit pixel group having four nine-units.

[0012] Figure 2 FIG. 2 is a diagram illustrating an image sensor including a pixel array disposed as a 6x6 unit pixel group according to one embodiment of the present disclosure.

[0013] Figure 3 FIG. 3 is a diagram illustrating a detailed circuit of the pixel array shown in FIG. 2 according to one embodiment of the present disclosure. Figure 2

[0014] Figure 4 FIG. 4 is a diagram illustrating a 4-sum mode output timing of the image sensor shown in FIG. 2 according to one embodiment of the present disclosure. Figure 3

[0015] Figure 5 FIG. 5 is a diagram illustrating a detailed circuit of a pixel array disposed as a 6x6 unit pixel group according to one embodiment of the present disclosure.

[0016] Figure 6 FIG. 6 is a diagram illustrating a 4-sum mode output timing of the image sensor shown in FIG. 5 according to one embodiment of the present disclosure. Figure 5 ​​A diagram of 8 sum mode output timing of the image sensor shown.

[0017] Figure 7 is a diagram illustrating an image sensor including a pixel array arranged as a 6x6 unit pixel group according to one embodiment of the present disclosure.

[0018] Figure 8 is a diagram illustrating an image sensor including a pixel array arranged as a 6x6 unit pixel group according to one embodiment of the present disclosure.

[0019] Figure 9 is a diagram illustrating a schematic configuration of an image processing system including a pixel array according to one embodiment of the present disclosure.

[0020] Figure 10 is a diagram illustrating a detailed configuration of an image sensor according to one embodiment of the present disclosure. Figure 9 DETAILED DESCRIPTION

[0021] In order to describe the present disclosure in detail so that those of ordinary skill in the art to which the present disclosure pertains can easily carry out the technical spirit of the present disclosure, various embodiments of the present disclosure are described below with reference to the accompanying drawings.

[0022] In all of the disclosure, like reference numerals refer to like parts throughout the various drawings and embodiments of the present disclosure.

[0023] Hereinafter, a pixel array including a 6x6 unit pixel group will be described with reference to Figure 1 Figure 1 is a diagram illustrating a pixel array of a type arranged as a 6x6 unit pixel group having four nine units.

[0024] Figure 1 The 6x6 pixel group 10 shown includes a first nine unit, a second nine unit, a third nine unit, and a fourth nine unit.

[0025] The first nine unit is arranged with 3x3 pixels each having a B color, the second nine unit is arranged with 3x3 pixels each having a Gb color, the third nine unit is arranged with 3x3 pixels each having a Gr color, and the fourth nine unit is arranged with 3x3 pixels each having an R color.

[0026] ​​When each of the nine (3x3) pixels in units 1 through 49 is driven simultaneously, a total of 9 data points can be read out. However, because each of the nine pixels in units 1 through 49 is not an even number of pixels, it is impossible to extract the phase difference of all pixels using microlenses positioned in units 1 through 49. This is because when color filters positioned below the microlenses (in the vertical direction) have different colors, it is difficult to determine whether the difference in readout values ​​is due to a color-related difference or a phase difference caused by the focusing of the microlenses.

[0027] In the following text, see references Figures 2 to 4 An image sensor 100 according to an embodiment is described. Figure 2 This is a diagram illustrating an image sensor 100 comprising a pixel array configured as 6x6 unit pixel groups according to an embodiment of the present disclosure. Figure 3 This illustrates an embodiment according to the present disclosure. Figure 2 The diagram shows a detailed circuit of the pixel array, and Figure 4 This illustrates an embodiment according to the present disclosure. Figure 2 The diagram shows the output timing of the image sensor 100.

[0028] The image sensor 100 according to an embodiment includes a center pixel group 110, a color pixel group 120, and a microlens in a 6x6 unit pixel group.

[0029] The center pixel group 110 is set as 2x2 pixels in the center area of ​​a 6x6 unit pixel group and has different colors. The center pixel group 110 may include: a first center pixel group Gb17 and Gb18, each with a 1x2 pixel of Gb color, and a second center pixel group Gr19 and Gr20, each with a 1x2 pixel of Gr color.

[0030] The first center pixel group Gb17 and Gb18 of the center pixel group 110 may have pixels of the same color as the second color pixel group 124 in the color pixel group 120, and the second center pixel group Gr19 and Gr20 may have pixels of the same color as the third color pixel group 126 in the color pixel group 120. The positions of the first center pixel group Gb17 and Gb18 and the second center pixel group Gr19 and Gr20 may be interchanged.

[0031] refer to Figure 3The charges sensed by the four photodiodes PD17, PD18, PD19, and PD20 included in the first and second center pixel groups Gb17 and Gb18 and Gr19 and Gr20 of the center pixel group 110 can be transferred to and accumulated in the floating diffusion node FD9 by the four transfer transistors Tx17, Tx18, Tx19, and Tx20. That is, in the center pixel group 110, the four photodiodes PD17, PD18, PD19, and PD20 and the four transfer transistors Tx17, Tx18, Tx19, and Tx20 can share one floating diffusion node FD9.

[0032] The color pixel groups 120 include first, second, third, and fourth color pixel groups 122, 124, 126, and 128 each having different colors.

[0033] The first to fourth color pixel groups (i.e., the boundary pixel groups) 122, 124, 126, and 128 can be arranged as 2x4 pixels or 4x2 pixels of units to surround the center pixel group 110.

[0034] That is, the first color pixel group 122 each having 2x4 pixels of B color (B1, B2, B3, B4, B13, B14, B15, and B16) can be arranged at the upper left, the second color pixel group 124 each having 4x2 pixels of Gb color (Gb25, Gb26, Gb27, Gb28, Gb29, Gb30, Gb31, and Gb32) can be arranged at the upper right, the third color pixel group 126 each having 4x2 pixels of Gr color (Gr5, Gr6, Gr7, Gr8, Gr9, Gr10, Gr11, and Gr12) can be arranged at the lower left, and the fourth color pixel group 128 each having 2x4 pixels of R color (R21, R22, R23, R24, R33, R34, R35, and R36) can be arranged at the lower right.

[0035] Referring to Figure 3 Each of the first to fourth color pixel groups 122, 124, 126, and 128 can include a first sub color pixel group and a second sub color pixel group.

[0036] More specifically, by switching the four transfer transistors Tx1, Tx2, Tx3, and Tx4, the charges sensed by the four first photodiodes PD1, PD2, PD3, and PD4 in the first sub-color pixel groups B1, B2, B3, and B4 of the first color pixel group 122 can be transferred to and accumulated in a first floating diffusion node FD1. That is, in the first sub-color pixel groups B1, B2, B3, and B4 of the first color pixel group 122, the four first photodiodes PD1, PD2, PD3, and PD4 and the four transfer transistors Tx1, Tx2, Tx3, and Tx4 can share one first floating diffusion node FD1.

[0037] Because the configurations and operations of the reset transistors Rx, the drive transistors Dx, and the selection transistors Sx are well known to those skilled in the art, their descriptions are omitted.

[0038] By switching the four transfer transistors Tx13, Tx14, Tx15, and Tx16, the charges sensed by the four second photodiodes PD13, PD14, PD15, and PD16 in the second sub-color pixel groups B13, B14, B15, and B16 of the first color pixel group 122 can be transferred to and accumulated in a second floating diffusion node FD2. That is, in the second sub-color pixel groups B13, B14, B15, and B16 of the first color pixel group 122, the four second photodiodes PD13, PD14, PD15, and PD16 and the four transfer transistors Tx13, Tx14, Tx15, and Tx16 can share one second floating diffusion node FD2.

[0039] By switching the four transfer transistors Tx25, Tx26, Tx27, and Tx28, the charges sensed by the four first photodiodes PD25, PD26, PD27, and PD28 in the first sub-color pixel groups Gb25, Gb26, Gb27, and Gb28 of the second color pixel group 124 can be transferred to and accumulated in a first floating diffusion node FD3.

[0040] By switching the four transfer transistors Tx29, Tx30, Tx31, and Tx32, the charges sensed by the four second photodiodes PD29, PD30, PD31, and PD32 in the second sub-color pixel groups Gb29, Gb30, Gb31, and Gb32 of the second color pixel group 124 can be transferred to and accumulated in a second floating diffusion node FD4.

[0041] The charges sensed by the four first photodiodes PD5, PD6, PD7, and PD8 in the first sub color pixel group Gr5, Gr6, Gr7, and Gr8 of the third color pixel group 126 can be transferred to and accumulated in the first floating diffusion node FD5 by switching four transfer transistors Tx5, Tx6, Tx7, and Tx8.

[0042] The charges sensed by the four second photodiodes PD9, PD10, PD11, and PD12 in the second sub color pixel group Gr9, Gr10, Gr11, and Gr12 of the third color pixel group 126 can be transferred to and accumulated in the second floating diffusion node FD6 by switching four transfer transistors Tx9, Tx10, Tx11, and Tx12.

[0043] The charges sensed by the four first photodiodes PD21, PD22, PD23, and PD24 in the first sub color pixel group R21, R22, R23, and R24 of the fourth color pixel group 128 can be transferred to and accumulated in the first floating diffusion node FD7 by switching four transfer transistors Tx21, Tx22, Tx23, and Tx24.

[0044] The charges sensed by the four second photodiodes PD33, PD34, PD35, and PD36 in the second sub color pixel group R33, R34, R35, and R36 of the fourth color pixel group 128 can be transferred to and accumulated in the second floating diffusion node FD8 by switching four transfer transistors Tx33, Tx34, Tx35, and Tx36.

[0045] At the top of each of the first color pixel group to the fourth color pixel group 122, 124, 126, and 128 and the first center pixel group Gb17 and Gb18 and the second center pixel group Gr19 and Gr20, the microlenses can be symmetrically disposed as a 1x2 pixel unit in the horizontal direction to detect the phase difference therebetween.

[0046] That is, for each 1x2 pixel in the 6x6 unit pixel group, the microlenses can be symmetrically disposed in the horizontal direction.

[0047] As shown in FIGS. 1, 2, 3, 4, 5, and 6, the center pixel group 110 and each of the first color pixel group to the fourth color pixel group 122, 124, 126, and 128 can be formed in an even array, and thus the existing 2x2 pixel driving method can be used, and the 4-sum mode operation can be performed in a four-quadrant pattern. Figure 2 Figure 3

[0048] Referring to FIGS. 1, 2, 3, 4, 5, and 6, the center pixel group 110 and each of the first color pixel group to the fourth color pixel group 122, 124, 126, and 128 can be formed in an even array, and thus the existing 2x2 pixel driving method can be used, and the 4-sum mode operation can be performed in a four-quadrant pattern. Figure 4 ​​In the 4-sum mode, an analog-to-digital converter (ADC) of the image sensor 100 including a 6x6 unit pixel group can perform a readout operation only at the third timing.

[0049] That is, at the first timing after a reset signal (Rx) having a high level (H) is applied to the reset transistor, a readout operation is performed on the transfer transistors TX1 to TX4 included in the first sub color pixel groups B1, B2, B3, and B4 of the first color pixel group 122, the transfer transistors TX13 to TX16 included in the second sub color pixel groups B13, B14, B15, and B16 of the first color pixel group 122, and the transfer transistors TX25 to TX28 included in the first sub color pixel groups Gb25, Gb26, Gb27, and Gb28 of the second color pixel group 124. Next, at the second timing, a readout operation is performed on the transfer transistors TX5 to TX8 included in the first sub color pixel groups Gr5, Gr6, Gr7, and Gr8 of the third color pixel group 126, the transfer transistors TX17 to TX20 included in the center pixel group 110, and the transfer transistors TX29 to TX32 included in the second sub color pixel groups Gb29, Gb30, Gb31, and Gb32 of the second color pixel group 124.

[0050] At the third timing, a readout operation is performed on the transfer transistors TX9 to TX12 included in the second sub color pixel groups Gr9, Gr10, Gr11, and Gr12 of the third color pixel group 126, the transfer transistors TX21 to TX24 included in the first sub color pixel groups R21, R22, R23, and R24 of the fourth color pixel group 128, and the transfer transistors TX33 to TX36 included in the second sub color pixel groups R33, R34, R35, and R36 of the fourth color pixel group 128.

[0051] Hereinafter, referring to Figure 5 and Figure 6 an image sensor according to another embodiment of the disclosure is described. Figure 5 is a diagram illustrating a detailed circuit of a pixel array arranged as a 6x6 unit pixel group according to an embodiment of the disclosure, and Figure 6 is a diagram illustrating a detailed circuit of a pixel array arranged as a 6x6 unit pixel group according to an embodiment of the disclosure. Figure 5 is a diagram illustrating 8-sum mode output timing of the image sensor shown in FIG. 8.

[0052] Because other components except for the dual-gain conversion transistors are the same as those of the pixel array arranged as a 6x6 unit pixel group shown in FIG. 8, a description of other components except for the dual-gain conversion transistors DCG1, DCG2, DCG3, and DCG4 is omitted. Figure 5 Because other components except for the dual-gain conversion transistors are the same as those of the pixel array arranged as a 6x6 unit pixel group shown in FIG. 8, a description of other components except for the dual-gain conversion transistors DCG1, DCG2, DCG3, and DCG4 is omitted. Figure 3 Because other components except for the dual-gain conversion transistors are the same as those of the pixel array arranged as a 6x6 unit pixel group shown in FIG. 8, a description of other components except for the dual-gain conversion transistors DCG1, DCG2, DCG3, and DCG4 is omitted.

[0053] The dual gain conversion transistors DCG1, DCG2, DCG3, and DCG4 can selectively couple two floating diffusion nodes corresponding to the same color.

[0054] That is, the first dual gain conversion transistor DCG1 can selectively couple a first floating diffusion node FD1 included in the first color pixel group 122 to a second floating diffusion node FD2 included in the first color pixel group 122, and the second dual gain conversion transistor DCG2 can selectively couple a third floating diffusion node FD3 included in the second color pixel group 124 to a fourth floating diffusion node FD4 included in the second color pixel group 124.

[0055] The third dual gain conversion transistor DCG3 can selectively couple a fifth floating diffusion node FD5 included in the third color pixel group 126 to a sixth floating diffusion node FD6 included in the third color pixel group 126, and the fourth dual gain conversion transistor DCG4 can selectively couple a seventh floating diffusion node FD7 included in the fourth color pixel group 128 to an eighth floating diffusion node FD8 included in the fourth color pixel group 128.

[0056] Reference Figure 6 In the 8-sum mode, an analog-to-digital converter (ADC) of the image sensor including the 6x6 unit pixel group can perform a readout operation only at the second timing.

[0057] That is, when a voltage having a high level (H) is applied to each of the first to fourth dual gain conversion transistors DCG1, DCG2, DCG3, and DCG4, the first and second floating diffusion nodes FD1 and FD2 included in the first color pixel group 122 are coupled to each other, the third and fourth floating diffusion nodes FD3 and FD4 included in the second color pixel group 124 are coupled to each other, the fifth and sixth floating diffusion nodes FD5 and FD6 included in the third color pixel group 126 are coupled to each other, and the seventh and eighth floating diffusion nodes FD7 and FD8 included in the fourth color pixel group 128 are coupled to each other.

[0058] That is, the pixels B1 to B4 and B13 to B16 included in the first color pixel group 122, the pixels Gb25 to Gb32 included in the second color pixel group 124, the pixels Gr5 to Gr12 included in the third color pixel group 126, and the pixels R21 to R24 and R33 to R36 included in the fourth color pixel group 128 can each operate in the 8-sum mode.

[0059] Accordingly, at a first timing after a reset signal (Rx) having a high level is applied to the reset transistor, the transfer transistors TX1 to TX4 and TX13 to TX16 included in the first color pixel group 122 and the transfer transistors TX25 to TX28 and TX29 to TX32 included in the second color pixel group 124 are turned on.

[0060] Next, at a second timing, the transfer transistors TX5 to TX12 included in the third color pixel group 126 and the transfer transistors TX21 to TX24 and TX33 to TX36 included in the fourth color pixel group 128 are turned on.

[0061] Accordingly, the readout speed of an analog-digital converter (ADC) of the image sensor can be improved by 150%.

[0062] Hereinafter, referring to Figure 7 An image sensor 200 including a pixel array arranged as 6x6 unit pixel groups according to yet another embodiment of the disclosure is described. Figure 7 FIG. 2 is a diagram illustrating an image sensor 200 including a pixel array arranged as 6x6 unit pixel groups according to an embodiment of the disclosure.

[0063] As Figure 7 illustrated, the image sensor 200 according to the embodiment includes a center pixel group 210, a color pixel group 220, and a microlens in the 6x6 unit pixel group.

[0064] The center pixel group 210 is arranged as 2x2 pixels in a center region of the 6x6 unit pixel group and has different colors. The center pixel group 210 can include a first center pixel group Gb18 and Gb20 each having 2x1 pixels of a Gb color and a second center pixel group Gr17 and Gr19 each having 2x1 pixels of a Gr color.

[0065] The first center pixel group Gb18 and Gb20 of the center pixel group 210 can have pixels of the same color as a second color pixel group 224 of the color pixel group 220, and the second center pixel group Gr17 and Gr19 of the center pixel group 210 can have pixels of the same color as a third color pixel group 226 of the color pixel group 220.

[0066] Because Figure 7 the color pixel group 220 illustrated has the same configuration as the color pixel group 120 illustrated in Figure 2 , a description thereof is omitted.

[0067] At the top of each of the first and second center pixel groups Gb18 and Gb20 and Gr17 and Gr19 of the first to fourth color pixel groups 222, 224, 226, and 228 and the center pixel group 210, the microlenses can be symmetrically disposed as a 2x1 pixel unit in the vertical direction to detect a phase difference therebetween.

[0068] That is, for each 2x1 pixel in the 6x6 unit pixel group, the microlenses can be symmetrically disposed in the vertical direction.

[0069] Hereinafter, referring to Figure 8 An image sensor 300 including a pixel array disposed as a 6x6 unit pixel group according to still another embodiment of the disclosure is described. Figure 8 is a diagram illustrating an image sensor 300 including a pixel array disposed as a 6x6 unit pixel group according to an embodiment of the disclosure.

[0070] As Figure 8 shown, the image sensor 300 according to the embodiment includes a center pixel group 310, a color pixel group 320, and a microlens in a 6x6 unit pixel group.

[0071] The center pixel group 310 is disposed as 2x2 pixels in a center region of the 6x6 unit pixel group and has different colors. The center pixel group 310 can include a first 1x1 pixel B17 having a B color, a second 1x1 pixel Gb18 having a Gb color, a third 1x1 pixel Gr19 having a Gr color, and a fourth 1x1 pixel R20 having an R color.

[0072] The first 1x1 pixel B17 of the center pixel group 310 can have the same color as a first color pixel group 322 in the color pixel group 320, the second 1x1 pixel Gb18 of the center pixel group 310 can have the same color as a second color pixel group 324 in the color pixel group 320, the third 1x1 pixel Gr19 of the center pixel group 310 can have the same color as a third color pixel group 326 in the color pixel group 320, and the fourth 1x1 pixel R20 of the center pixel group 310 can have the same color as a fourth color pixel group 328 in the color pixel group 320.

[0073] Because Figure 8 the color pixel group 320 shown has the same configuration as the color pixel group 120 shown in Figure 2 , a description thereof is omitted.

[0074] The microlens can include a first microlens and a second microlens.

[0075] The first microlens can be disposed as a 2x2-pixel unit symmetrically up and down and left and right at the top of each of the first to fourth color pixel groups 322, 324, 326, and 328.

[0076] The second microlens can be disposed as a 1x1-pixel unit at the top of each of the first to fourth 1x1 pixels B17, Gb18, Gr19, and R20 to cover the first to fourth 1x1 pixels B17, Gb18, Gr19, and R20, respectively.

[0077] Figure 9 is a schematic block diagram illustrating an image processing system 1000 including a pixel array 1110 according to an embodiment of the disclosure.

[0078] As Figure 9 indicated, the image processing system 1000 can include an image sensor 1100, a digital signal processor (DSP) 1200, a display unit 1300, and a lens module 1500.

[0079] The image sensor 1100 can include a pixel array 1110, a row driver 1120, a correlated double sampling (CDS) block 1130, an analog-to-digital converter (ADC) block 1140, a ramp signal generator 1160, a timing generator 1170, a control register block 1180, and a buffer 1190.

[0080] The image sensor 1100 can detect an optical image of an object 1400 captured through the lens module 1500 under the control of the DSP 1200. The DSP 1200 can output an image detected and output by the image sensor 1100 to the display unit 1300. The display unit 1300 is a device that can display an image output from the DSP 1200. For example, the display unit 1300 can be a terminal of a computer, a mobile communication device, and other image output devices.

[0081] The DSP 1200 can include a camera controller 1201, an image signal processor (ISP) 1203, and an interface (I / F) 1205.

[0082] The camera controller 1201 can control the operation of the control register block 1180. The camera controller 1201 can control the operation of the image sensor 1100, i.e., the operation of the control register block 1180, by using an I 2 C (integrated circuit bus), but the technical spirit of the disclosure is not limited thereto.

[0083] The ISP 1203 can receive an image (or image data), can process the received image for human body recognition, and output the processed image to the display unit 1300 through the I / F 1205. Although Figure 7 The ISP 1203 is shown to be located in the DSP 1200, but in different embodiments, the ISP 1203 can be located in the image sensor 1100. Also, the image sensor 1100 and the ISP 1203 can be implemented in a single package, such as a multi-chip package (MCP).

[0084] The pixel array 1110 can include a pixel array according to the above-described embodiments. Specifically, the pixel array 1110 can include a center pixel group including 2x2 pixels disposed in a center region of a 6x6 unit pixel group to have at least two different colors, and first to fourth color pixel groups having the same color as one pixel of the center pixel group, disposed as a unit of 2x4 pixels to surround the center pixel group and having different colors, respectively.

[0085] Figure 10 is a block diagram illustrating an image sensor 1100 according to an embodiment of the disclosure. Figure 9 The detailed block diagram of the image sensor 1100 shown.

[0086] Referring to Figure 9 and Figure 10 The timing generator 1170 can generate at least one control signal for controlling operations of the row driver 1120, the CDS block 1130, the ADC block 1140, and the ramp signal generator 1160. The control register block 1180 can generate at least one control signal for controlling operations of the ramp signal generator 1160, the timing generator 1170, and the buffer 1190. The control register block 1180 can operate under the control of the camera controller 1201.

[0087] The row driver 1120 can drive the pixel array 1110 in units of rows. For example, the row driver 1120 can generate a selection signal for selecting one row among a plurality of rows. Each of the plurality of rows includes a plurality of pixels. For ease of description, the arrangement of the plurality of pixels is schematically shown, and the plurality of pixels can include a pixel array according to the above-described embodiments. Figure 8 The arrangement of the plurality of pixels shown, and the plurality of pixels can include a pixel array according to the above-described embodiments.

[0088] Each of the plurality of pixels can sense incident light and output an image reset signal and an image signal to the CDS block 1130. Specifically, the pixel array 1110 can include a center pixel group including 2x2 pixels in a center region among 6x6 unit pixel groups to have different colors, and first to fourth color pixel groups each having a unit of 2x4 pixels to surround the center pixel group and have different colors, respectively, which have the same color as one pixel of the center pixel group.

[0089] The CDS block 1130 can perform a correlated double sampling operation on each of the received image reset signal and image signal. The ADC block 1140 can compare a ramp signal Ramp output from the ramp signal generator 1160 with a correlated double sampling signal output from the CDS block 1130, output a comparison signal, count a level transition time of the comparison signal according to a clock signal CNT_CLK, and output a count value to the buffer 1190.

[0090] The ADC block 1140 can include a comparison block 1145 and a counter block 1150. The comparison block 1145 can include a plurality of comparators. Each of the plurality of comparators is coupled to the CDS block 1130 and the ramp signal generator 1160. Each of a plurality of output signals output from the CDS block 1130 is input to a first input terminal, for example, a (-) input terminal, of each comparator, and the ramp signal Ramp output from the ramp signal generator 1160 is input to a second input terminal, for example, a (+) input terminal, of each comparator.

[0091] The plurality of comparators can receive a corresponding output signal output from the CDS block 1130 and the ramp signal Ramp output from the ramp signal generator 1160, compare the corresponding output signal with the ramp signal Ramp, and output a comparison signal. For example, a comparison signal output from a first comparator 1147 for comparing a signal output from each of the plurality of pixels with the ramp signal Ramp can correspond to a difference between an image signal and an image reset signal that varies according to an illuminance of light incident from the outside.

[0092] The ramp signal generator 1160 can operate under the control of the timing generator 1170.

[0093] The counter block 1150 can include a plurality of counters 1151. The plurality of counters 1151 are respectively coupled to output terminals of the comparators. The counter block 1150 can count a level transition time of the comparison signal according to a clock signal CNT_CLK output from the timing generator 1170, and output a digital signal, i.e., a count value. The counter block 1150 can output a plurality of digital image signals. Each of the plurality of counters 1151 can be implemented as a reversible counter or a bit-reversal counter.

[0094] The buffer 1190 can store each of the plurality of digital image signals output from the ADC block 1140, sense and amplify each of the stored digital image signals, and output the amplified digital image signals. The buffer 1190 can include a storage block 1191 and a sense amplifier 1192. The storage block 1191 can include a plurality of memories 1193 each for storing a count value output from each of the plurality of counters 1151. For example, the count value can refer to a count value associated with a signal output from a plurality of pixels.

[0095] The sense amplifier 1192 can sense and amplify each of the count values output from the storage block 1191. The image sensor 1100 can output image data to the DSP 1200.

[0096] According to an embodiment of the disclosure, an image sensor and an image processing system can implement 4-sum mode or 8-sum mode operation in a quad pattern while using an existing 2x2 driving mode, thereby improving output readout speed of the image sensor.

[0097] In addition, since the microlenses are symmetrically disposed at the center of the 6x6 unit pixels and on top of each of the color filters, left and right or up and down, a phase difference can be detected.

[0098] The effects and advantages of the disclosure are not limited to the above-described embodiments, and other effects and advantages that are not described herein will be apparent to those skilled in the art based on the above detailed description.

[0099] While the disclosure has been shown and described with respect to particular embodiments, the disclosed embodiments are provided to describe, not to limit. Also, it is noted that those skilled in the art will recognize that the disclosure can be implemented in various embodiments that fall within the scope of the appended claims. Furthermore, the described embodiments can be combined to form additional embodiments.

Claims

1. An image sensor comprising: a center pixel group including 2x2 pixels having at least two different colors and disposed in a center region of a 6x6 unit pixel group; and first through fourth color pixel groups each corresponding to a respective color, the first through fourth color pixel groups being disposed as a 2x4 or 4x2 unit to surround the center pixel group, wherein the first through fourth color pixel groups having different colors between the first through fourth color pixel groups, and each of the first through fourth color pixel groups including the 2x4 or 4x2 pixels having a same color.

2. The image sensor of claim 1, wherein, each of the first through fourth color pixel groups including: a first sub-color pixel group including a plurality of first photodiodes and a first floating diffusion node sharing the plurality of first photodiodes; and a second sub-color pixel group including a plurality of second photodiodes and a second floating diffusion node sharing the plurality of second photodiodes, wherein the first and second sub-color pixel groups include pixels of a same color. each of the first through fourth color pixel groups further including a dual gain conversion transistor adapted to selectively couple the first floating diffusion node to the second floating diffusion node.

3. The image sensor of claim 2, wherein, a microlens disposed to cover the center pixel group and the first through fourth color pixel groups and adapted to share pixels included in and having a same color of each of the center pixel group and the first through fourth color pixel groups.

4. The image sensor of claim 1, further comprising: the shared pixels included in and having a same color of each of the first through fourth color pixel groups include 2x1, 1x2, or 2x2 pixels.

5. The image sensor of claim 4, wherein, the shared pixels included in and having a same color of the center pixel group include 2x1 or 1x2 pixels.

6. The image sensor of claim 4, wherein, 7. The image sensor of claim 1, when the center pixel of the center pixel group includes four different 1x1 color pixels, further comprising: a first microlens disposed to cover each of the 2x2 pixels of the first through fourth color pixel groups and adapted to share the 2x2 pixels included in and having a same color of each of the first through fourth color pixel groups; and a second microlens disposed to cover each of the center pixels.

8. An image sensor comprising: a first sub-color pixel group including a plurality of first photodiodes and a first floating diffusion node sharing the plurality of first photodiodes; a second sub-color pixel group including a plurality of second photodiodes and a second floating diffusion node sharing the plurality of second photodiodes; and a dual gain conversion transistor adapted to selectively couple the first floating diffusion node to the second floating diffusion node, ​ wherein, The first sub-color pixel group and the second sub-color pixel group have pixels of the same color.

9. An image processing system comprising: an image sensor adapted to detect an optical image of an object and output image data; a digital signal processor adapted to receive the image data, process the received image, and provide an output image; and a display device adapted to display the output image, wherein the image sensor comprises: a center pixel group comprising 2x2 pixels having at least two different colors and disposed in a center region of a 6x6 unit pixel group; and a first color pixel group, a second color pixel group, a third color pixel group, and a fourth color pixel group, each color pixel group corresponding to a respective color, the first color pixel group to the fourth color pixel group disposed as a 2x4 pixel or 4x2 pixel unit to surround the center pixel group, wherein the first color pixel group to the fourth color pixel group have different colors between the first color pixel group to the fourth color pixel group, and each of the first color pixel group to the fourth color pixel group comprises the 2x4 pixel or 4x2 pixel having the same color.

10. The image processing system of claim 9, wherein, Each of the first color pixel group to the fourth color pixel group comprises: a first sub-color pixel group comprising a plurality of first photodiodes and a first floating diffusion node sharing the plurality of first photodiodes; a second sub-color pixel group comprising a plurality of second photodiodes and a second floating diffusion node sharing the plurality of second photodiodes, wherein the first sub-color pixel group and the second sub-color pixel group comprise pixels of the same color; and a dual gain conversion transistor adapted to selectively couple the first floating diffusion node to the second floating diffusion node.

11. The image processing system of claim 9, wherein, a first 1x2 pixel of the center pixel group has the same color as the first color pixel group, and a second 1x2 pixel of the center pixel group has the same color as the second color pixel group.

12. The image processing system of claim 11, further comprising: microlenses disposed as a 1x2 pixel unit left-right symmetrically to cover the first color pixel group to the fourth color pixel group and the first 1x2 pixel and the second 1x2 pixel of the center pixel group.

13. The image processing system of claim 9, wherein, a first 2x1 pixel of the center pixel group has the same color as the first color pixel group, and a second 2x1 pixel of the center pixel group has the same color as the second color pixel group.

14. The image processing system of claim 13, further comprising: microlenses disposed as a 2x1 pixel unit up-down symmetrically to cover the first color pixel group to the fourth color pixel group and the first 2x1 pixel and the second 2x1 pixel of the center pixel group.

15. The image processing system of claim 13, wherein, The first 1x1 pixel of the center pixel group has the same color as the first color pixel group, the second 1x1 pixel of the center pixel group has the same color as the second color pixel group, the third 1x1 pixel of the center pixel group has the same color as the third color pixel group, and the fourth 1x1 pixel of the center pixel group has the same color as the fourth color pixel group.

16. The image processing system of claim 15, further comprising: a first microlens disposed symmetrically up and down and left and right as a 2x2 pixel unit to cover each of the first to fourth color pixel groups; and a second microlens disposed to cover each of the first to fourth 1x1 pixels of the center pixel group.

17. An image sensor, comprising: a center pixel group having at least two sub-pixel groups each corresponding to a different color; and a plurality of boundary pixel groups each corresponding to a respective color and disposed to surround the center pixel group, wherein the center pixel group and the plurality of boundary pixel groups forming a 6x6 unit pixel group having a top row and a bottom row opposite the top row, wherein the center pixel group has 2x2 pixels and the plurality of boundary pixel groups have different colors among the plurality of boundary pixel groups, and each of the plurality of boundary pixel groups includes 2x4 pixels or 4x2 pixels having the same color.

18. The image sensor of claim 17, wherein, The boundary pixel groups include: a first color pixel group of 2x4 B pixels disposed at an upper left portion of a top side of the 6x6 unit pixel group; a second color pixel group of 4x2 Gb pixels disposed at an upper right portion of the top side of the 6x6 unit pixel group; a third color pixel group of 4x2 Gr pixels disposed at a lower left portion of a bottom side of the 6x6 unit pixel group; and a fourth color pixel group of 2x4 R pixels disposed at a lower right portion of the bottom side of the 6x6 unit pixel group. The center pixel group includes:

19. The image sensor of claim 18, wherein, a first center pixel group having 1x2 Gb pixels; and a second center pixel group having 1x2 Gr pixels. The center pixel group includes:

20. The image sensor of claim 18, wherein, a first center pixel group having 2x1 Gr pixels; and a second center pixel group having 2x1 Gb pixels. The center pixel group includes: a 1x1 B pixel disposed at an upper left portion of the center pixel group relative to the top side of the 6x6 unit pixel group; 21. The image sensor of claim 18, wherein, a 1x1 GB pixel disposed at an upper right portion of the center pixel group relative to the top side of the 6x6 unit pixel group; a 1x1 Gr pixel disposed at a lower left portion of the center pixel group relative to the bottom side of the 6x6 unit pixel group; and a 1x1 R pixel disposed at a lower right portion of the center pixel group relative to the bottom side of the 6x6 unit pixel group. ​ ​ ​

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