image sensor

Abstract

An image sensor including: a Bayer pattern type pixel array including a plurality of Bayer pattern type extension blocks each having first to fourth pixel blocks, each of the first to fourth pixel blocks including first to fourth pixels, the first and fourth pixels of the first to fourth pixel blocks being configured to sense green light, the first and fourth pixels of the second and third pixel blocks being configured to sense red and blue light, respectively, and the second and third pixels of the first to fourth pixel blocks being configured to sense white light; and a signal processing unit merging Bayer pattern color information generated from the first and fourth pixels of the first to fourth pixel blocks with Bayer pattern illumination information generated from the second and third pixels of the first to fourth pixel blocks.

Description

[0001] Cross-references to related applications

[0002] This application claims priority to Korean Patent Application No. 10-2020-0053244, filed on May 4, 2020, with the Korean Intellectual Property Office, the entire disclosure of which is incorporated herein by reference for all purposes. Technical Field

[0003] Some example implementations involve image sensors. Background Technology

[0004] Image sensors, which capture images of objects and convert those images into electrical signals, are used not only in consumer electronics such as digital cameras, mobile phone cameras, and portable camcorders, but also in cameras installed in automobiles, security equipment, and / or robots. Such image sensors include an array of pixels, and each pixel in the pixel array may include a light-sensing element.

[0005] To increase the resolution of an image sensor, the size of pixels is continuously reduced, and the sensitivity of the light-sensing element in each pixel may decrease due to the reduction in pixel size. As a result, the image quality may deteriorate. Summary of the Invention

[0006] Some example embodiments provide an image sensor in which dynamic range (DR) and / or signal-to-noise ratio (SNR) can be improved by compensating for the low sensitivity of color pixels.

[0007] According to some example embodiments, an image sensor includes: a Bayer patterned pixel array including a plurality of Bayer patterned extension blocks, each of the plurality of Bayer patterned extension blocks having a first pixel block to a fourth pixel block arranged in a larger 2×2 matrix, each of the first pixel blocks to the fourth pixel block including a first pixel to a fourth pixel arranged in a smaller 2×2 matrix, the first pixel and the fourth pixel of the first pixel block and the fourth pixel block being configured to sense green light, the first pixel and the fourth pixel of the second pixel block and the third pixel block being configured to sense red light and blue light, respectively, and the second pixel and the third pixel of the first pixel block to the fourth pixel block being configured to sense white light; and a signal processing circuit configured to generate Bayer patterned color information by binning the signals of the first pixel and the fourth pixel of the first pixel block to the fourth pixel block, to generate Bayer patterned illuminance information by binning the signals of the second pixel and the third pixel of the first pixel block to the fourth pixel block, and to generate a color image by merging the Bayer patterned color information and the Bayer patterned illuminance information.

[0008] According to some example embodiments, an image sensor, comprising: a pixel array comprising a plurality of Bayer pattern type extended blocks each having a first pixel block to a fourth pixel block, the first pixel block to the fourth pixel block each comprising a plurality of pixels arranged into a plurality of rows and a plurality of columns, the plurality of pixels being divided into a first group and a second group each having at least two pixels, the pixels of the first group of the first pixel block and the fourth pixel block each being configured to sense a first color light, the pixels of the first group of the second pixel block being configured to sense a second color light, the pixels of the first group of the third pixel block being configured to sense a third color light, and the pixels of the second group of the first pixel block to the fourth pixel block each being configured to sense a light of a waveband wider than a waveband of each of at least the second color light and the third color light; and a signal processing circuit configured to generate a Bayer pattern color information by binning signals of the pixels of the first group of the first pixel block to the fourth pixel block, to generate a Bayer pattern illumination information by binning signals of the pixels of the second group of the first pixel block to the fourth pixel block, and to generate a color image by merging the Bayer pattern color information with the Bayer pattern illumination information.

[0009] According to some example embodiments, an image sensor, comprising: a pixel array comprising a plurality of Bayer pattern type extended blocks each having a first pixel block to a fourth pixel block arranged into a larger 2x2 matrix, each of the first pixel block to the fourth pixel block comprising a first pixel to a fourth pixel arranged into a smaller 2x2 matrix, the first pixel and the fourth pixel of the first pixel block and the fourth pixel block each being configured to receive a first color light, the first pixel and the fourth pixel of the second pixel block and the third pixel block each being configured to receive a second color light and a third color light, and the second pixel and the third pixel of the first pixel block to the fourth pixel block being configured to receive a white light; and a signal processing circuit configured to generate a Bayer pattern color information by binning signals of the first pixel and the fourth pixel of the first pixel block to the fourth pixel block, and to generate a Bayer pattern illumination information by binning signals of the second pixel and the third pixel of the first pixel block to the fourth pixel block. The first pixel block and the fourth pixel block are arranged in a first diagonal direction, the second pixel block and the third pixel block are arranged in a second diagonal direction, the first pixel and the fourth pixel are arranged in one of the first diagonal direction and the second diagonal direction, and the second pixel and the third pixel are arranged in the other of the first diagonal direction and the second diagonal direction. BRIEF DESCRIPTION OF DRAWINGS

[0010] The above and other aspects, features, and advantages of the example embodiments will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which:

[0011] Figure 1is a block diagram showing a structure of an image sensor according to some example embodiments;

[0012] Figure 2 is a block diagram schematically showing an image sensor according to some example embodiments;

[0013] Figure 3 is a plan view showing a pixel array employable in an image sensor according to some example embodiments;

[0014] Figure 4A and Figure 4B show Bayer pattern color (e.g., RGB) information and illuminance information generated by signal processing of an image sensor according to some example embodiments, respectively;

[0015] Figure 5 shows a Bayer pattern color image incorporating Figure 4A the color array pattern shown in Figure 4B and the illuminance information shown in

[0016] Figure 6 is a partial plan view showing the pixel array shown in Figure 1

[0017] Figure 7 shows an example of a drive circuit corresponding to the pixel array shown in Figure 6

[0018] is a plan view showing a pixel array including autofocus pixels according to some example embodiments; Figure 8

[0019] is a cross-sectional view showing an autofocus pixel of the pixel array shown in Figure 9 Figure 8 is a plan view showing a pixel array including autofocus pixels according to some example embodiments;

[0020] Figure 10 is a cross-sectional view showing an autofocus pixel of the pixel array shown in

[0021] Figure 11 Figure 10 is a plan view showing a pixel array employable in an image sensor according to some example embodiments; and

[0022] Figure 12 and

[0023] Figure 13A show Bayer pattern color information and illuminance information generated by signal processing of an image sensor according to some example embodiments, respectively. Figure 13B ​​​​DETAILED DESCRIPTION

[0024] Hereinafter, various example embodiments will be described in detail with reference to the accompanying drawings.

[0025] Figure 1 is a block diagram illustrating a structure of an image sensor according to some example embodiments.

[0026] Reference Figure 1 The image sensor 500 according to some example embodiments can include a pixel array 100, a signal processing unit 200, and a control unit 300. The image sensor 500 can further include a memory 400.

[0027] As will be discussed in more detail below Figure 3 As shown in, the pixel array 100 employed in some example embodiments can have a plurality of pixels PX constituting / included in an extended Bayer pattern block EB. The extended Bayer pattern block EB can be composed of four pixel blocks PB1, PB2, PB3, and PB4, respectively, which are adjacently arranged, for example, as shown. Each of the plurality of pixels PX can include an optical sensing element that converts an optical signal into an electrical signal. For example, the optical sensing element can be or include or correspond to a photodiode.

[0028] The plurality of pixels PX can include a red pixel R, a green pixel G, and a blue pixel B configured to receive red light, green light, and blue light, respectively, and a white pixel W configured to receive white light. The white pixel W can have a higher sensitivity than the red pixel R, the green pixel G, and the blue pixel B. The red pixel R, the green pixel G, and the blue pixel B include red, green, and blue filters, respectively, to receive light in a specific waveband (e.g., wavebands of red light, green light, and blue light, respectively), while the white pixel W can receive light covering the wavebands of red, green, and blue without a filter. The red pixel R, the green pixel G, the blue pixel B, and the white pixel W receive light of one of red, green, blue, and white in a pixel unit through a microlens (e.g., see microlens 109 in Figure 8 The optical sensing element can generate and output an electrical signal corresponding to an intensity of light received through photoelectric conversion.

[0029] In some example embodiments, the plurality of pixels PX constituting / included in the pixel array 100 can be arranged in a plurality of rows and a plurality of columns. For example, Figure 3 is shown in the form of arranging 64 pixels PX in an 8x8 matrix for ease of description, but the form can have an array of one million or more pixels (e.g., 1920x1080). In detail, as described above, the arrangement as described above can be constituted / included in a pixel block (PB1, PB2, PB3, PB4) unit and an extended Bayer pattern block (EB) unit.

[0030] In detail, the pixel array 100 can include a plurality of extended Bayer pattern blocks EB each having first to fourth pixel blocks PB1, PB2, PB3, and PB4 arranged in a 2x2 matrix (e.g., a larger matrix), which are adjacently arranged, for example, as illustrated. The first to fourth pixel blocks PB1, PB2, PB3, and PB4 can be arranged in a larger matrix, and can each include first to fourth pixels PX1, PX2, PX3, and PX4 arranged in a smaller 2x2 matrix, which are adjacently arranged as illustrated.

[0031] In each of the plurality of extended Bayer pattern blocks EB employed in some example embodiments, the first and fourth pixel blocks PX1 and PX4 can be arranged in a first diagonal line (DL1) direction, and the second and third pixel blocks PX2 and PX3 can be arranged in a second diagonal line (DL2) direction.

[0032] Further, the first and fourth pixels PX1 and PX4 of the first and fourth pixel blocks PB1 and PB4 can be green pixels G configured to sense green light. The first and fourth pixels PX1 and PX4 of the second and third pixel blocks PB2 and PB3 can be red and green pixels R and G configured to sense red and blue light, respectively. The second and third pixels PX2 and PX3 of the first to fourth pixel blocks PB1, PB2, PB3, and PB4 can be white pixels W configured to sense white light.

[0033] In some example embodiments, in each of the first to fourth pixel blocks PB1, PB2, PB3, and PB4, the first and fourth pixels PX1 and PX4 can be arranged in a first diagonal line DL1 direction, and the second and third pixel blocks PX2 and PX3 can be arranged in a second diagonal line DL2 direction. In some example embodiments, the first to fourth pixel blocks PB1, PB2, PB3, and PB4 can be arranged in a direction opposite to the direction in the example embodiments. For example, the first and fourth pixels PX1 and PX4 are arranged in a second diagonal line DL2 direction, and the second and third pixel blocks PX2 and PX3 can be arranged in a first diagonal line DL1 direction.

[0034] As such, in some example embodiments, the first and fourth pixels PX1 and PX4 are set to color pixels indicated by R, G, and B, and the second and third pixels PX2 and PX3 can be set to an illumination sensing pixel to improve sensitivity. The illumination sensing pixel can be configured to receive light of a wider wavelength band than the color pixels, and may, for example, include a yellow pixel and / or a white pixel W.

[0035] According to some example embodiments, a "pixel block" refers to a unit in which a plurality of color pixels (e.g., PX1 and PX4) and a plurality of luminance sensing pixels (e.g., PX2 and PX3) are combined and arranged, and an "extended Bayer pattern block" refers to a unit in which four pixel blocks PB are arranged in a Bayer pattern. In some example embodiments, the extended Bayer pattern block EB can be understood as realizing a Bayer array pattern of R-G-G-B in terms of the color pixels of the first to fourth pixel blocks PB1, PB2, PB3, and PB4. In addition, Figure 4A The Bayer pattern color pattern information BP1 illustrated in FIG. 10A can have a Bayer array pattern of R-G-G-B corresponding to such a Bayer array.

[0036] As Figure 1 As illustrated in FIG. 10A, the output signals of the pixel array 100 are input to the binning pattern generation unit 240 of the signal processing unit 200. The binning pattern generation unit 240 can bin the RGBW array data obtained from the pixel array 100 into a color signal composed of RGB and an illuminance signal composed of W, and can generate color pattern information BP1 and illuminance pattern information BP2 generated respectively in accordance with the binned color signal and the binned illuminance signal. Since the color pattern information BP1 and the illuminance pattern information BP2 are generated respectively by such binning, signal processing such as gain and / or offset can be independently performed on the two pattern information BP1 and BP2.

[0037] The color pattern information BP1 and the illuminance pattern information BP2 generated by the binning pattern generation unit 240 have a Bayer pattern as illustrated in Figure 4A and 4B The respective patterns constituting the color pattern information BP1 and the illuminance pattern information BP2 can be or correspond to or be based on data based on or associated with signals obtained from one pixel block PB of the pixel array 100.

[0038] For example, the green pattern information of the first row and the first column of the color pattern information BP1 can be obtained from the signals of the two green pixels PX1 and PX4 of the first pixel block PB1. The white pattern information of the first row and the first column of the illuminance pattern information BP2 can be obtained from the signals of the remaining two white pixels PX2 and PX3 of the first pixel block PB1.

[0039] As described above, since each pattern of the color pattern information BP1 and the illuminance pattern information BP2 is generated based on one pixel block PB composed of four pixels PX, the resolution (m x n) of the Bayer pattern color information can be 1 / 4 (one fourth) of the resolution (2m x 2n) of the pixel array 100. The illuminance pattern information BP2 can also have the same arrangement of the Bayer pattern as the color pattern information BP1.

[0040] In the binned pattern generation unit 240, the color pattern information BP1 and the illuminance pattern information BP2 having the same Bayer pattern are input to the pattern merging unit 280 of the signal processing unit 200. The color pattern information BP1 and the illuminance pattern information BP2 can be merged to provide a color image MCI having the same resolution as the color pattern information BP1 (as shown in FIG. 6B, for example). The merging process can be performed in such a manner that the patterns in the positions corresponding to each other in the color pattern information BP1 and the illuminance pattern information BP2 are merged (e.g., overlapped) with each other one-to-one. Through the illuminance data at the corresponding positions of the illuminance pattern information BP2, each color R, G, and B of the color pattern information BP1 can have improved sensitivity characteristics, thereby providing the color image MCI having converted colors R', G', and B'. Figure 5

[0041] As described above, according to some example embodiments, the color pattern information BP1 obtained from the corresponding first pixel PX1 and fourth pixel PX4 is improved, for example, greatly improved in sensitivity characteristics such as SNR and / or DR, through the binned illuminance information BP2, as a result, since each pattern data of the illuminance pattern information BP2 is information obtained from a white pixel located or arranged to be adjacent in the same pixel block as the pixel block of the first pixel PX1 and the fourth pixel PX4, the first pixel PX1 and the fourth pixel PX4 are associated with the color signal to be merged, and thus the sensitivity can be appropriately improved according to the environment (e.g., neighborhood) of the relevant pixel.

[0042] In some example embodiments, the corrected color image MIC can be stored in the memory 400. The control unit 300 can control the signal processing unit 200 to perform a series of processes. For example, a program including machine-readable instructions to perform the series of processes can be stored in the memory 400, and the control unit 300 can control the series of processes by executing the program read from the memory 400.

[0043] ​According to some example embodiments, color pattern information BP1 and illuminance pattern information BP2 have a resolution of 1 / 4 (one-quarter) of the resolution of the physical pixel array (2m×2n), and the color image MCI has a resolution (m×n) in the same form as the resolution (m×n) of the color pattern information BP1. However, the example embodiments are not limited to this, and the configuration can be configured to have different resolutions.

[0044] For example, by configuring digital signal processing differently, the color pattern information BP1, illuminance pattern information BP2, and color image MCI can be implemented with resolutions different from those in other example embodiments. In some example embodiments, the resolution of the color pattern information BP1 and illuminance pattern information BP2 can be the same as the resolution of the physical pixel array (2m×2n).

[0045] In some embodiments, the resolution of color pattern information BP1 is the same as the resolution of the pixel array (2m×2n), but the resolution of illuminance pattern information BP2 can be 1 / 4 of the resolution of the pixel array (2m×2n). In this case, the color image MCI has the same resolution as the color pattern information BP1, and the merging process of color pattern information BP1 and illuminance pattern information BP2 can be performed as a 4:1 (color pattern: illuminance pattern) merging mode instead of a one-to-one merging process.

[0046] like Figure 2 As shown, the image sensor 500 according to some example embodiments may include: a row driver 340, driven by a control unit 300' together with the pixel array 100 and the signal processing unit 200; and a control unit 300'.

[0047] As described above, the pixel array 100 may include a plurality of pixels PX arranged in units of extended Bayer pattern blocks EB and multiple pixel blocks PB. Each pixel in the pixel PX may include a corresponding optical sensing element. For example, the optical sensing element may be or include a photodiode. The plurality of pixels PX absorb light to generate an electric charge, and can provide an electrical signal (output voltage) to the signal reader 350 according to the generated charge.

[0048] The control unit 300' can control the row driver 340 to enable the pixel array 100 to absorb light to accumulate charge, temporarily store the accumulated charge, and output an electrical signal to the outside of the pixel array 100 according to the stored charge. Alternatively or additionally, the control unit 300' can control the signal reader 350 to measure the output voltage provided by the pixel array 100. Figure 2The control unit 300' shown in FIG. 3 is / corresponds to a control unit responsible for a control function configured to drive the pixel array 100 and read a signal, and can be understood as being responsible for Figure 1 the control unit 300 of a part of the function of the control unit shown in FIG. 3.

[0049] The row driver 340 can generate signals such as RS, TX, and SELS for controlling the pixel array 100, and provide the signals to the plurality of pixels PX included in the pixel array 100. The row driver 340 can determine the activation and deactivation timing of the reset control signal RSs, the transfer control signal TXs, and / or the selection signal SELS for the plurality of pixels PX, and can provide other signals to the plurality of pixels PX included in the pixel array 100.

[0050] The signal reader 350 can include a correlated double sampler (CDS) 351, an analog / digital (A / D) converter (ADC) 353, and / or a buffer 355. The correlated double sampler 351 can sample and hold the output voltage provided by the pixel array 100. The correlated double sampler 351 can double sample the levels according to a certain noise level and the generated output voltage, and can output a level corresponding to the difference. Alternatively or additionally, the correlated double sampler 351 can receive a ramp signal generated by a ramp signal generator 357, and can compare the signals to output a comparison result. The A / D converter 353 can convert an analog signal corresponding to the level received from the correlated double sampler 351 into a digital signal. The buffer 355 can latch the digital signal, and the latched signal can be sequentially output to the signal processing unit 200 and / or the outside of the image sensor 500.

[0051] The signal processing unit 200 can perform signal processing on the received data of the plurality of pixels PX. In addition to the process of generating a Bayer pattern color image by combining the color pattern and the illumination pattern obtained by the binning described above, the signal processing unit 200 can perform various image signal processing for image quality improvement, such as array interpolation, other noise reduction processing, gain adjustment, waveform shaping processing, and / or color filter array interpolation, white balance processing, gamma correction, edge emphasis processing, etc. Alternatively or additionally, the signal processing unit 200 can output information about the plurality of pixels PX to a processor (not shown) to perform phase difference calculation during phase difference auto focus (see Figure 8 to Figure 11 ).

[0052] In some example embodiments, the signal processing unit 200 is shown as being implemented in a part of the image sensor 500 (in detail, in a logic circuit), but can also be implemented in a processor (not shown) separately provided outside the image sensor 500.

[0053] Figure 6 is shown illustrating Figure 1 a partial plan view of the pixel array shown in

[0054] Referring to Figure 6 , a portion of the pixel array 100 shown in Figure 1 , for example, one extended Bayer pattern block EB.

[0055] The extended Bayer pattern block EB includes first to fourth pixel blocks PB1, PB2, PB3, and PB4 arranged in a 2x2 matrix (e.g., arranged adjacent as shown and as described above), and the first to fourth pixel blocks PB1, PB2, PB3, and PB4 include first and fourth pixels PX1 and PX4 arranged diagonally, each of the first and fourth pixels PX1 and PX4 included in different pixel blocks PB1 to PB4 respectively receive different colors of light, and second and third pixels PX2 and PX3 respectively receive white light.

[0056] The first to fourth pixel blocks PB1, PB2, PB3, and PB4 employed in some example embodiments can include one floating diffusion FD shared by the first to fourth pixels PX1, PX2, PX3, and PX4 and transistors M1, M2, M3, and M4 (e.g., transfer transistors) arranged between the first to fourth pixels PX1, PX2, PX3, and PX4 and the floating diffusion FD. Charge accumulated in photodiodes PD1, PD2, PD3, and PD4 of the first to fourth pixels PX1, PX2, PX3, and PX4 can be sent to the floating diffusion FD through the transistors M1, M2, M3, and M4 connected to the photodiodes PD1, PD2, PD3, and PD4, respectively. In this way, the four pixels PX1, PX2, PX3, and PX4 located in the same pixel block PB1, PB2, PB3, and PB4 can share one floating diffusion FD. When sharing one floating diffusion FD as in some example embodiments, the same color information can be read in time difference. For example, some of the transistors M1 and M4 can be turned on at the same time to store and read green color information from the photodiodes PD1 and PD4 in the floating diffusion FD, and subsequently, some other transistors M2 and M3 can be turned on at the same time to store and read illumination (e.g., white) information from the photodiodes PD2 and PD3 in the floating diffusion FD.

[0057] In some example embodiments, a floating diffusion FD can be set to be shared by two adjacent pixels of the same color, so that two floating diffusions FD can be set in one pixel block. For example, green pixels PX1 and PX4 can share one floating diffusion FD, and white pixels PX2 and PX3 can share another floating diffusion FD. In this case, all the transistors M1 to M4 are turned on at the same time to store information in the two floating diffusions FD, and green information and white information can be read at the same time.

[0058] Figure 7 The circuit of the pixel block PB1 including the four pixels PX1, PX2, PX3, and PX4 shown in FIG. 1 is shown as a part of the pixel circuit corresponding to the pixel array. Figure 6 The circuit of the pixel block PB1 including the four pixels PX1, PX2, PX3, and PX4 shown in FIG. 1 is shown as a part of the pixel circuit corresponding to the pixel array.

[0059] The process of generating an image signal in each pixel will be described with reference to Figure 7

[0060] When light enters the pixel, charges depending on the amount of light are generated (inside) in the photodiodes PD1, PD2, PD3, and PD4 by photoelectric conversion. The charges accumulated in the photodiodes PD1, PD2, PD3, and PD4 are sent to the floating diffusion portion FD through the transistors (transfer transistors) M1, M2, M3, and M4. The transistors M1, M2, M3, and M4 can be controlled by control signals of the transfer signal lines TR1, TR2, TR3, and TR4, respectively. Reference can be made to Figure 7 The operation process will be described in detail.

[0061] First, a reset signal RS is applied to the (reset) transistor M5, and the charges accumulated in the floating diffusion FD are reset. When the amount of charges sufficiently reaches a reset level, a row selection signal SL is applied to the transistor M4, and the source current of the transistor M3 based on the amount of charges of the floating diffusion FD flows to the column signal line SIG, and can be sent to the A / D converter 353 as a reset level (see Figure 6 ).

[0062] Next, the reset signal RS and the row selection signal SL are turned off, a transfer signal TS is applied to the transistor M5, and the charges generated by the photodiode PD1 are sent to the floating diffusion FD. When the transfer is sufficiently completed, the column selection signal SL is applied to the transistor M7, and the source current of the transistor M6 based on the amount of charges of the floating diffusion FD flows to the row signal line SIG, and can be sent to the A / D converter as a pixel signal level (see Figure 2 the A / D converter 313 in FIG. 3). In the A / D converter, a correct pixel signal can be obtained by detecting the difference between the reset level and the pixel signal level.

[0063] ​In this way, in the pixel circuit according to some example embodiments, the transistors M5, M6 and M7 can be shared by the pixels PX1, PX2, PX3 and PX4 (in) the same pixel block together with the floating diffusion FD.

[0064] In some example embodiments, in the pixel blocks PB of the 2x2 matrix, the exposure time of some pixels can be adjusted differently from the exposure time of other pixels. For example, the pixels PX1 and PX4 of the same color of the first to fourth pixel blocks PB1, PB2, PB3 and PB4 can be controlled with different exposure times. Similarly, the same white pixels PX2 and PX3 in each pixel block can be controlled with different exposure times. This control can be performed by the control unit 300’ shown in Figure 2 However, the example embodiments are not limited thereto.

[0065] For example, the control unit 300 in Figure 2 may control the pixels PX1 and PX3 among the first to fourth pixels PX1, PX2, PX3 and PX4 located in the 2m-1th row (m≥1) with a first exposure time, and can control the pixels PX2 and PX4 located in the 2mth row with a second exposure time shorter than the first exposure time.

[0066] In this way, by causing the same color pixels of the same pixel block to synthesize the pixel signal through the first exposure time (e.g., longer time) and the pixel signal through the second exposure time (e.g., shorter time) by differentiating the first exposure time and the second exposure time, a wider dynamic range (WDR) can be provided, and the final color image (MCI) can be expressed in detail by bright and dark areas.

[0067] Figure 8 is a plan view showing a pixel array (including an autofocus pixel) according to an example embodiment, and Figure 9 is a cross-sectional view showing an autofocus pixel of the pixel array shown in Figure 8

[0068] Referring to Figure 8 and Figure 9 , the pixel array 100A according to some example embodiments can be understood as similar to the pixel array 100 of Figure 3 , except for having a pixel for autofocus (or, a shared pixel for phase detection). Alternatively or additionally, unless explicitly stated to the contrary, components of this example embodiment can be understood by reference to the description of the same or similar components of the pixel array 100 described in Figure 1 to Figure 3

[0069] ​​The pixel array 100A according to the present example embodiment includes a plurality of pixels PX arranged in a plurality of rows and a plurality of columns, and can be similar to the pixel array 100 shown in FIG. 1A. Figure 3 The pixel array 100A according to the present example embodiment is arranged in units of a pixel block (PB) and an extended Bayer-patterned block (EB) similarly to the pixel array 100 shown in FIG. 1B. The plurality of pixels PX can include shared pixels AF for phase detection, for autofocus.

[0070] The shared pixels AF for phase detection each include a first phase detection pixel FD1 and a second phase detection pixel FD2 for sensing light of the same color. For example, the first phase detection pixel FD1 and the second phase detection pixel FD2 can include pixels for sensing green light. Unlike other pixels for obtaining image information, the first phase detection pixel FD1 and the second phase detection pixel FD2 can be used not only for an autofocus function using a phase difference but also for measurement of a distance between an object and an image sensor.

[0071] Since the first phase detection pixel FD1 and the second phase detection pixel FD2 are arranged adjacent to each other and configured to sense the same color, the first phase detection pixel FD1 and the second phase detection pixel FD2 can partially deviate from regularity of the arrangement employed in the pixel array according to the present example embodiment. In the case of a signal processing process, information of the pixel deviating from the regularity of the arrangement can be replaced with information of other adjacent pixels. For example, in the signal processing process, the second phase detection pixel FD2 can be replaced with information of other white pixels located in the same pixel block.

[0072] The plurality of shared pixels AF for phase detection can be arranged in different regions. In some example embodiments, the first phase detection pixel FD1 and the second phase detection pixel FD2 can include a pair arranged in a row direction and a pair arranged in a column direction.

[0073] In detail, referring to FIG. 2A, Figure 9 The first phase detection pixel FD1 and the second phase detection pixel FD2 each include a light sensing element PD1 and PD2, a light-blocking layer 108, an insulating layer 106, a color filter layer 107, and a microlens 109. The light-blocking layer 108 employed in the present example embodiment is arranged in the insulating layer 106, and can include a reflective metal material. The light-blocking layer 108 employed in the present example embodiment can have a shape spanning between two pixels FD1 and FD2.

[0074] The light-blocking layer 108 can block a portion of light incident to the optical sensing elements PD1 and PD2. Depending on the incident direction of light, the amount of light received by the light sensing elements PD1 and PD2 can differ. As described above, it can be determined whether to obtain focus based on the difference in the amount of light received by the first phase detection pixel FD1 and the second phase detection pixel FD2. Based on this, a lens (not shown) can be adjusted to be auto-focused. The shared pixel AF for phase detection in which the first phase detection pixel FD1 and the second phase detection pixel FD2 are arranged in a row direction is used to adjust the focus in the horizontal direction, and the shared pixel AF for phase detection in which the first phase detection pixel FD1 and the second phase detection pixel FD2 are arranged in a column direction can be used to adjust the focus in the vertical direction.

[0075] Figure 10 is a plan view illustrating a pixel array (including auto-focus pixels) according to an example embodiment, and Figure 11 is a plan view illustrating Figure 10 a cross-sectional view of an auto-focus pixel of the pixel array illustrated in

[0076] Referring to Figure 10 and Figure 11 , the pixel array 100A' according to some example embodiments can be understood to be similar to the pixel array 100A of Figure 8 and Figure 9 except that the pixel structure for auto-focus is different. In addition, components of these example embodiments can be understood by reference to the description of the same or similar components of the pixel arrays 100 and 100A described in Figure 1 to Figure 3 and Figure 8 and Figure 9 , unless otherwise noted.

[0077] The shared pixel AF for phase detection used in the previous embodiment is illustrated in the form of using a light-blocking layer 108, but the shared pixel AF' for phase detection according to the present example embodiment can include one microlens 109' instead of the light-blocking layer 108, which is configured to be shared by the first phase detection pixel FD1' and the second phase detection pixel FD2'.

[0078] The microlens 109' shared by the first phase detection pixel FD1' and the second phase detection pixel FD2' can adjust the incident light directed to the respective optical sensing elements PD1 and PD2. The first phase detection pixel FD1 and the second phase detection pixel FD2 can output different phase signals depending on the shape and / or refractive index of the microlens 109' employed in this example embodiment. The focus can be adjusted based on the different phase signals. Similar to some example embodiments, the shared pixels AF for phase detection of the first phase detection pixel FD1 and the second phase detection pixel FD2 arranged in the row direction are used to adjust the focus in the horizontal direction, and the shared pixels AF for phase detection of the first phase detection pixel FD1 and the second phase detection pixel FD2 arranged in the column direction can be used to adjust the focus in the vertical direction.

[0079] Figure 12 is a plan view illustrating a pixel array employable in an image sensor according to some example embodiments, and Figure 13A and respectively illustrate color information and luminance information generated through signal processing by an image sensor according to example embodiments. Figure 13B Referring to

[0080] , the pixel array 100B according to this example embodiment can be understood as similar to the pixel array 100 of Figure 12 except that the pixels (or, shared pixels for phase detection) are arranged for auto-focusing. In addition, components of some example embodiments can be understood by reference to the description of the same or similar components of the pixel array 100 described in Figure 3 . Unless explicitly stated to the contrary, the components of some example embodiments can be understood by reference to the description of the same or similar components of the pixel array 100 described in Figure 1 to Figure 3 .

[0081] The pixel array 100B includes a plurality of pixels PX arranged in a multi-row and multi-column arrangement, and similar to the previous embodiments, can be arranged in units of pixel blocks PB1, PB2, PB3, and PB4, and an extended Bayer pattern block (EB).

[0082] Referring to Figure 12 , similar to the pixel array 100 illustrated in Figure 3 , in which the pixel array 100B includes a plurality of extended Bayer pattern blocks (EB) having first to fourth pixel blocks PB1, PB2, PB3, and PB4 arranged in a 2x2 matrix, respectively, but unlike some example embodiments, the first to fourth pixel blocks PB1, PB2, PB3, and PB4 can each include nine pixels PX arranged in a 3x3 matrix.

[0083] In each of the pixel blocks PB1, PB2, PB3, and PB4, the 5 pixels PX arranged in two diagonal directions DL1 and DL2 are configured to detect color light, while the remaining four pixels can be configured to detect white light. In detail, the five color pixels PX of the first pixel block PB1 and the fourth pixel block PB4 can be green pixels G configured to sense green light. The five color pixels PX of the second pixel block PB2 and the third pixel block PB3 can be red pixels R and green pixels G configured to sense red light and blue light, respectively. The four white pixels PX of the first pixel block to the fourth pixel block PB1, PB2, PB3, and PB4 can be / correspond to white pixels W configured to sense white light.

[0084] As described above, the "pixel blocks (PB1, PB2, PB3, PB4)" employed in some example embodiments can have various pixel arrangements that combine a plurality of color pixels with a plurality of illuminance detection pixels, while the "extended Bayer pattern block (EB)" can have an R-G-G-B Bayer pattern arranged with the four pixel blocks PB1, PB2, PB3, and PB4 similar to the previous embodiment.

[0085] The output signals of the pixel array 100 are binned into color signals composed of RGB and an illuminance signal composed of W in a binning pattern generation unit (240) in Figure 1 The color pattern information BP1' and the illuminance pattern information BP2' are generated from the binned color signals and the illuminance signal, respectively, as shown in Figure 13A and Figure 13B The color pattern information BP1' and the illuminance pattern information BP2' can be merged in a pattern merging unit (see 280 of Figure 1 to provide a color image having the same resolution as the color pattern information BP1'.

[0086] Since one of the color pattern information BP1' and the illuminance pattern information BP2' is generated by one pixel block of the pixel array 100, the color pattern information BP1', the illuminance pattern information BP2', and the final color image can have resolutions corresponding to the arrangement of the pixel blocks. For example, when the number of the first pixel block to the fourth pixel block PB1, PB2, PB3, and PB4 in the pixel array 100 in the row direction and the number of the first pixel block to the fourth pixel block PB1, PB2, PB3, and PB4 in the pixel array 100 in the column direction are m and n, respectively, the color information and the illuminance information (BP1', BP2') of the Bayer pattern type and the final color image can each have a resolution of m x n.

[0087] The merging process can be performed in a manner in which the patterns in the positions corresponding to each other in the color pattern information BP1 and the illuminance pattern information BP2 are merged one after another with each other. Each color R, G, and B of the color pattern information BP1’ can provide a color image with improved sensitivity characteristics by the illuminance data at the corresponding positions of the illuminance pattern information BP2.

[0088] As described above, according to some example embodiments, the color pattern information BP1’ obtained from the five pixels PX in each pixel block is improved by the binned illuminance pattern information BP2’, for example, the sensitivity characteristics such as SNR and DR are greatly improved, as a result, a Bayer pattern color image with improved or excellent image quality can be output. Since each pattern data of the illuminance pattern information BP2’ is information obtained from four white pixels PX located adjacent to the five color pixels PX in the same pixel block, the five color pixels are associated with the color signals to be merged, and thus the sensitivity can be appropriately improved according to the environment / neighborhood of the corresponding pixels.

[0089] In the above-described embodiments, although the pixel array provided as a combination of color pixels indicated by R, G, and B and an illuminance sensing pixel indicated by W is shown, the color pixels and / or the illuminance sensing pixel can be partially changed. In some example embodiments, at least a part of the color pixels can be changed to other colors. For example, pixels (in detail, filters) for detecting yellow, cyan, and / or magenta colors can be included. Alternatively or additionally, the illuminance sensing pixel can be configured to detect light of a wavelength band wider than that of the color pixels. For example, in addition to the white pixel W, the illuminance sensing pixel can include another pixel, for example, a yellow pixel. Alternatively or additionally, the illuminance sensing pixel can be configured to detect light of a wavelength band greater than the visible wavelength.

[0090] As described above, according to some example embodiments, the pixel array is constructed by appropriately combining color pixels receiving colors (for example, RGB) with an illuminance sensing pixel (for example, white) to improve sensitivity, and color pattern information and / or illuminance pattern information can be respectively generated by binning the signals obtained from the pixel array. The color pattern information can be provided as a Bayer pattern, and the illuminance pattern information can be configured as a pattern having illuminance information corresponding one-to-one to each pixel information. The color pattern and the illuminance pattern can be merged to output a Bayer pattern color image with improved image quality in terms of SNR and / or dynamic range (DR).

[0091] Each or at least some of the above-described elements, such as but not limited to elements described as "units" or "devices", such as the pattern merging unit 280, the control unit 300, the memory 400, and / or elements ending with "-er" or "-ine", can comprise processing circuitry, such as hardware comprising logic circuitry; a hardware / software combination, such as a processor executing software; or a combination of both. For example, the processing circuitry can more particularly comprise, but is not limited to, a Central Processing Unit (CPU), an Arithmetic Logic Unit (ALU), a Digital Signal Processor, a microcomputer, a Field-Programmable Gate Array (FPGA), a System-on-Chip (SoC), a programmable logic unit, a microprocessor, an Application-Specific Integrated Circuit (ASIC), etc.

[0092] While some example embodiments have been shown and described above, it will be apparent to those having ordinary skill in the art that modifications and changes can be made without departing from the scope of the example embodiments as defined in the appended claims.

Claims

1. An image sensor, comprising: a first 4x4 pixel array comprising four green pixels, eight white pixels, two blue pixels, and two red pixels; and a second 4x4 pixel array comprising six green pixels, six white pixels, two blue pixels, and two red pixels. The second 4x4 pixel array comprises a first autofocus pixel and a second autofocus pixel.

2. The image sensor of claim 1, wherein, 3. The image sensor of claim 2, further comprising a microlens, and the microlens is disposed on the first autofocus pixel and the second autofocus pixel. wherein, The first autofocus pixel and the second autofocus pixel are green pixels.

4. The image sensor of claim 3, wherein, A first blue pixel, a first white pixel, the first autofocus pixel, and the second autofocus pixel are arranged in a row of the second 4x4 pixel array.

5. The image sensor of claim 4, wherein, The first blue pixel and the first autofocus pixel and the second autofocus pixel are sequentially arranged in a first direction, and 6. The image sensor of claim 5, wherein, wherein the first blue pixel is disposed immediately adjacent to the first autofocus pixel.

7. The image sensor of claim 6, further comprising a third autofocus pixel and a fourth autofocus pixel, and wherein the third autofocus pixel and the fourth autofocus pixel are green pixels, and the first autofocus pixel and the second autofocus pixel are arranged in a first direction, and wherein wherein the third autofocus pixel and the fourth autofocus pixel are arranged in a second direction perpendicular to the first direction. The second 4x4 pixel array comprises a third autofocus pixel and a fourth autofocus pixel, and 8. The image sensor of claim 6, wherein, wherein the third autofocus pixel and the fourth autofocus pixel are green pixels. The first autofocus pixel and the second autofocus pixel are arranged in a first direction, and 9. The image sensor of claim 8, wherein, wherein the second autofocus pixel and the third autofocus pixel are arranged in a second direction perpendicular to the first direction.

10. An image sensor, comprising: a 6x5 pixel array comprising a plurality of white pixels, a plurality of green pixels, a plurality of blue pixels, a plurality of red pixels, and first through fourth autofocus pixels, and wherein the first and second autofocus pixels, first and second white pixels, first and green pixels in the 6x5 pixel array are arranged in a first direction, and wherein the first green pixel, third white pixel, first red pixel, and third autofocus pixel in the 6x5 pixel array are arranged in a second direction perpendicular to the first direction. The third autofocus pixel, the fourth autofocus pixel, second blue pixel, fourth white pixel, second green pixel, and fifth white pixel in the 6x5 pixel array are arranged in a first direction.

11. The image sensor of claim 10, wherein, The fifth white pixel, the second green pixel, the fourth white pixel, the second blue pixel, the fourth autofocus pixel, and the third autofocus pixel are sequentially arranged in a first direction.

12. The image sensor of claim 11, wherein, 13. The image sensor of claim 10, further comprising a microlens, and ​ wherein, The microlens is disposed on the first autofocus pixel and the second autofocus pixel, and The first autofocus pixel and the second autofocus pixel are green pixels.

14. The image sensor of claim 13, wherein, The second green pixel, the fourth white pixel, the fifth white pixel, the second red pixel, and the second autofocus pixel in the 6x5 pixel array are arranged in a second direction.

15. The image sensor of claim 14, wherein, The second autofocus pixel, the fourth white pixel, the second red pixel, the fifth white pixel, and the second green pixel are sequentially arranged in a second direction.

16. The image sensor of claim 11, wherein, The first autofocus pixel to the fourth autofocus pixel are green pixels, and The first autofocus pixel and the second autofocus pixel are arranged in a first direction, and the fourth autofocus pixel and the third autofocus pixel are arranged in the first direction.

17. The image sensor of claim 16, further comprising a microlens, and wherein The microlens is disposed on the first autofocus pixel and the second autofocus pixel.

18. The image sensor of claim 17, wherein, The first autofocus pixel is disposed on a first corner of four corners of the 6x5 pixel array, and The third autofocus pixel is disposed on a second corner of the four corners of the 6x5 pixel array, and The first corner is located on a diagonal line of the second corner.

19. The image sensor of claim 18, further comprising a fifth autofocus pixel and a sixth autofocus pixel.

20. An image sensor, comprising: an 8x8 pixel array comprising a plurality of white pixels, a plurality of green pixels, a plurality of blue pixels, a plurality of red pixels, a first autofocus pixel to an eighth autofocus pixel, and a first microlens to a fourth microlens, and The first microlens is disposed on the first autofocus pixel and the second autofocus pixel, the second microlens is disposed on the third autofocus pixel and the fourth autofocus pixel, the third microlens is disposed on the fifth autofocus pixel and the sixth autofocus pixel, and the fourth microlens is disposed on the seventh autofocus pixel and the eighth autofocus pixel, and The first autofocus pixel and the second autofocus pixel are arranged in a first direction, the third autofocus pixel and the fourth autofocus pixel are arranged in a second direction perpendicular to the first direction, and The first autofocus pixel to the eighth autofocus pixel are green pixels.

Images