Image sensing device

Abstract

The present application discloses an image sensing device, which includes a plurality of pixel groups, each pixel group including first to fourth unit pixels configured to respond to incident light and generate electrical signals, and wherein each of the first to fourth unit pixels of the pixel group includes a filter operable to transmit incident light corresponding to the same color, wherein the first unit pixel and the second unit pixel included in the pixel group are arranged adjacent to each other and include a portion of a first microlens, and wherein the size of a light receiving area of ​​a third unit pixel of the pixel group is smaller than the size of a light receiving area of ​​a fourth unit pixel of the pixel group.

Description

Technical Field

[0001] The technology and implementation methods disclosed in this patent document generally relate to an image sensing device, and more particularly, to an image sensor capable of performing a phase difference detection autofocus (PDAF) function. Background Art

[0002] Image sensing devices are used in electronic devices to convert optical images into electrical signals. Recent developments in the automotive, medical, computer, and communications industries have led to an increased demand for higher performance image sensing devices in various devices such as smart phones, digital cameras, camcorders, personal communication systems (PCS), game consoles, surveillance cameras, medical miniature cameras, robots, infrared (IR) sensing devices, etc.

[0003] Complementary metal oxide semiconductor (CMOS) image sensing devices are now widely used due to certain advantages including, for example, higher frame rates and shutter speeds. CMOS image sensing devices and signal processing circuits can be integrated into a single chip, making it possible to miniaturize electronic devices while achieving lower power consumption. In addition, the use of CMOS manufacturing technology can lead to reduced production costs. These characteristics of CMOS image sensing devices make these sensors more suitable for implementation in mobile devices. Summary of the invention

[0004] Embodiments of the disclosed technology relate to an image sensing device capable of performing a phase difference detection auto focus (PDAF) function and a high dynamic range (HDR) imaging function.

[0005] Some embodiments of the disclosed technology relate to an image sensing device that receives signals generated by a plurality of unit pixels included in one pixel group and acquires a high dynamic range (HDR) image by performing image capturing only once using the received signals.

[0006] According to an embodiment of the disclosed technology, an image sensing device may include multiple pixel groups, each pixel group including first to fourth unit pixels configured to respond to incident light and generate electrical signals, and wherein each of the first to fourth unit pixels of the pixel group includes a filter operable to transmit incident light corresponding to the same color, wherein the first unit pixel and the second unit pixel included in the pixel group are arranged adjacent to each other and include a portion of a first microlens, and wherein a size of a light receiving area of ​​a third unit pixel of the pixel group is smaller than a size of a light receiving area of ​​a fourth unit pixel of the pixel group.

[0007] In some implementations, the filter is any one of a first filter configured to selectively pass red light, a second filter configured to selectively pass green light, or a third filter configured to selectively pass blue light.

[0008] In some implementations, a size of a light receiving area of ​​a first unit pixel of a pixel group is the same as a size of a light receiving area of ​​a second unit pixel of the pixel group.

[0009] In some implementations, a first unit pixel and a second unit pixel included in a pixel group are disposed adjacent to each other in a row direction of the pixel group.

[0010] In some implementations, a first unit pixel and a second unit pixel in another pixel group adjacent to the pixel group along a row direction include a portion of another first microlens, and wherein the first microlens of the pixel group and the other first microlens of the other pixel group are arranged in different rows.

[0011] In some implementations, a first unit pixel and a second unit pixel in another pixel group adjacent to the pixel group along a column direction include a portion of another first microlens, and the first microlens of the pixel group is arranged in a first row of the pixel group, and another first microlens of another pixel group is arranged in a first row of another pixel group.

[0012] In some implementations, a first unit pixel and a second unit pixel included in the pixel group are disposed adjacent to each other in a column direction of the pixel group.

[0013] In some implementations, a first unit pixel and a second unit pixel in another pixel group adjacent to the pixel group along a column direction include a portion of another first microlens, and wherein the first microlens of the pixel group and the other first microlens of the other pixel group are arranged in different columns.

[0014] In some implementations, a first unit pixel and a second unit pixel in another pixel group adjacent to the pixel group along a row direction include a portion of another first microlens, and wherein the first microlens of the pixel group is disposed in a first column of the pixel group, and another first microlens of another pixel group is disposed in a first column of another pixel group.

[0015] In some implementations, each pixel group may include a first light shielding structure formed along an outer edge of a third unit pixel and a second light shielding structure formed along an outer edge of a fourth unit pixel, wherein the first light shielding structure has a width greater than that of the second light shielding structure.

[0016] In some implementations, each pixel group may further include a third light shielding structure formed along outer edges of the first unit pixel and the second unit pixel, wherein the third light shielding structure has a smaller width than the second light shielding structure.

[0017] In some implementations, the third unit pixel and the fourth unit pixel include a second microlens and a third microlens, respectively.

[0018] In some implementations, the first microlens is formed to have a higher height than the second microlens or the third microlens.

[0019] According to another embodiment of the disclosed technology, an image sensing device may include: a pixel array, which includes pixel groups, each pixel group includes unit pixels arranged in a (2×2) matrix and configured to respond to incident light and generate signals corresponding to the incident light; and a processor, which is electrically connected to the pixel groups and configured to process signals generated by the unit pixels included in the pixel groups, wherein each pixel group also includes: first to fourth unit pixels including filters configured to transmit incident light of the same color; a microlens arranged to overlap with the first unit pixel and the second unit pixel, and wherein the size of the light receiving area of ​​the third unit pixel is smaller than the size of the light receiving area of ​​the fourth unit pixel, wherein the processor is configured to generate phase difference data, which indicates a phase difference between a first path for the incident light to reach the first unit pixel and a second path for the incident light to reach the second unit pixel.

[0020] In some implementations, the processor is configured to operate to generate first image data based on signals generated by the first unit pixel and the second unit pixel.

[0021] In some implementations, the processor is further configured to generate the second image data based on the signal generated by the third unit pixel, and to generate the third image data based on the signal generated by the fourth unit pixel.

[0022] In some implementations, the processor is configured to generate a high dynamic range (HDR) image using the first to third image data.

[0023] It is to be understood that both the foregoing general description and the following detailed description of the disclosed technology are exemplary and explanatory and are intended to provide further explanation of the disclosure as claimed. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The above and other features and advantageous aspects of the disclosed technology will become readily apparent with reference to the following detailed description when considered in conjunction with the accompanying drawings.

[0025] Figure 1is a block diagram illustrating an example of an image sensing device based on some implementations of the disclosed technology.

[0026] Figure 2 is a perspective diagram showing an example of a pixel array based on some implementations of the disclosed technology.

[0027] FIG. 3A to FIG. 3D are top views showing various examples of pixel groups based on some implementations of the disclosed technology.

[0028] Figure 4 is a graph illustrating an example of a response signal based on the intensity of incident light applied to each unit pixel included in a pixel group based on some implementations of the disclosed technology.

[0029] Figure 5 is a diagram showing some implementations based on the disclosed technology. Figure 4 The graph shown is a graph of the relationship between the average response corresponding to the average value of the signal response and the intensity of the incident light. DETAILED DESCRIPTION

[0030] The image sensing device may have a phase difference detection autofocus (PDAF) function that performs autofocus using a phase difference between detected images. The image sensing device may perform high dynamic range (HDR) imaging, which acquires multiple image data for different illumination environments, processes the acquired image data, synthesizes the processed image data, and thus forms a high dynamic range (HDR) image. However, when an HDR image is formed using multiple independently acquired image data, a time delay may occur when acquiring and processing the image data, and motion artifacts between the acquired image data may also occur.

[0031] Some implementations of the disclosed technology relate to an image sensing device capable of performing a phase difference detection autofocus (PDAF) function and a high dynamic range (HDR) imaging function. Some implementations of the disclosed technology relate to an image sensing device that receives a signal generated by a plurality of unit pixels included in a pixel group, and acquires a high dynamic range (HDR) image by performing image capture only once using the received signal. Some implementations of the disclosed technology provide an image sensing device that can perform a phase difference detection autofocus (PDAF) function, and can generate a high dynamic range (HDR) image using a plurality of signals generated by a pixel group. Some implementations of the disclosed technology provide an image sensing device that can use a plurality of signals generated by a pixel group, and can perform a single signal detection operation for a unit pixel included in a pixel array. Some implementations of the disclosed technology can provide a higher quality HDR image.

[0032] Reference will now be made in detail to embodiments of the disclosed technology, examples of which are illustrated in the accompanying drawings. Although the present disclosure is susceptible to various modifications and alternative forms, specific embodiments thereof are illustrated as examples in the accompanying drawings. However, the present disclosure should not be construed as being limited to the embodiments set forth herein.

[0033] Whenever possible, the same reference numerals will be used throughout the drawings to denote the same or similar parts. In the following description, detailed descriptions of related known configurations or functions incorporated herein will be omitted to avoid obscuring the subject matter.

[0034] Figure 1 is a block diagram showing an example of an image sensing device ISD based on some implementations of the disclosed technology. In more detail, Figure 1 Examples of a method of performing an auto focus (AF) function by an image sensing device ISD and a method of forming high dynamic range (HDR) image data by the image sensing device ISD are shown.

[0035] Reference Figure 1 , the image sensing device ISD may include an image pickup circuit 300 , an image sensor 100 , and a processor 200 .

[0036] The image pickup circuit 300 may receive light. In more detail, the image pickup circuit 300 may include a lens 310 , a lens driver 320 , an aperture 330 , and an aperture driver 340 .

[0037] The lens 310 may be implemented as a single lens, or may also be implemented as a plurality of lenses as desired.

[0038] The lens driver 320 may control the position of the lens 310 based on a control signal from the processor 200. As the position of the lens 310 is adjusted (or changed), the distance between the lens 310 and the object (S) (ie, target object) may also be adjusted (or changed).

[0039] The aperture 330 may adjust or control the amount of light to be incident on the lens 310 based on a control signal from the aperture driver 340. Since the amount of light to be incident on the lens 310 (i.e., the amount of received light) is adjusted by the aperture 330, the size of the signal generated by the image sensor 100 may also be adjusted in response to the adjusted amount of light.

[0040] The aperture driver 340 may adjust a value of the aperture 330 , such that the aperture driver 340 may adjust an amount of light to be incident on the lens 310 using the adjusted value of the aperture 330 .

[0041] The processor 200 may transmit a signal for adjusting the position of the lens 310 based on the signal generated by the image sensor 100 to the lens driver 320 , or may transmit a signal for adjusting the value of the aperture 330 to the aperture driver 340 .

[0042] The image sensor 100 may include a pixel array 110 , a correlated double sampler (CDS) 120 , an analog-to-digital converter (ADC) 130 , a buffer 140 , a row driver 150 , a timing generator 160 , a control register 170 , and a ramp signal generator 180 .

[0043] In some implementations, the pixel array 110 may include at least one pixel group. The pixel group may include a plurality of unit pixels arranged in a (2×2) matrix.

[0044] Incident light (ie, optical signal) having passed through the lens 310 and the aperture 330 may be imaged by the pixel array 110 so that the incident light may be converted into an electrical signal. The unit pixels may respectively generate electrical signals corresponding to the external object (S).

[0045] The unit pixel included in the pixel array 110 may absorb light to generate charges, and may output an electrical signal for the generated charges to a correlated double sampler (CDS) 120 .

[0046] Each unit pixel included in the pixel array 110 may include a microlens, a filter, a photoelectric conversion element, and a wiring layer.

[0047] The microlens may allow light incident on the pixel array 110 to be focused on the optical filter and the photoelectric conversion element. The optical filter may allow incident light having penetrated the microlens to selectively pass based on the wavelength of the incident light.

[0048] The photoelectric conversion element may generate a photocharge corresponding to the incident light that has penetrated the microlens and the filter. Each photoelectric conversion element may be implemented as a photodiode, a phototransistor, a photogate, a pinned photodiode (PPD), or a combination thereof. In the following description, it is assumed as an example that each photoelectric conversion element is implemented as a photodiode.

[0049] If the photoelectric conversion element is a photodiode, the photoelectric conversion element may include a stacked structure in which an N-type impurity region and a P-type impurity region are vertically stacked. The photoelectric conversion element may be formed in a semiconductor substrate. For example, the semiconductor substrate may be a P-type semiconductor substrate.

[0050] The wiring layer may be disposed below the photoelectric conversion element. Here, the wiring layer may also be referred to as a line layer as needed. The wiring layer may include a reset transistor, a transfer transistor, a floating diffusion (FD) region, a drive transistor, a select transistor, and the like.

[0051] The reset transistor may be enabled in response to a reset signal, so that the reset transistor may reset the potential of each unit pixel to a predetermined voltage level (eg, a pixel voltage level).

[0052] Additionally, when the reset transistor is enabled, the transfer transistor may also be enabled to reset the floating diffusion (FD) region.

[0053] Since the transfer transistor is enabled in response to a transmission (Tx) signal, the transfer transistor may transfer photocharges accumulated in a photoelectric conversion element of each pixel to a floating diffusion (FD) region.

[0054] The floating diffusion (FD) region may receive photocharges generated by the photoelectric conversion element, may accumulate the received photocharges, and thus may convert the accumulated photocharges into a voltage signal.

[0055] The drive transistor may receive a pixel voltage through its drain terminal and may be coupled to a floating diffusion (FD) region through its gate terminal. In addition, the drive transistor may be coupled to a select transistor through its source terminal.

[0056] The driving transistor may output a current corresponding to a voltage of a floating diffusion (FD) region coupled to a gate electrode of the driving transistor to a signal line through the selection transistor.

[0057] The selection transistor may be enabled in response to a selection signal applied to its gate electrode so that the selection transistor may transmit an output signal of the drive transistor to a signal line. The electrical signal applied to the signal line may be provided to a correlated double sampler (CDS) 120 .

[0058] The correlated double sampler (CDS) 120 may sample and hold an electrical signal received from the pixel array 110. The correlated double sampler (CDS) 120 may perform double sampling of a signal level caused by incident light and a specific noise level and thus may output a signal level corresponding to a difference between the sampled result signals.

[0059] An analog-to-digital converter (ADC) 130 may convert a received analog signal into a digital signal and may transmit the digital signal to a buffer 140 .

[0060] The buffer 140 may latch the received digital signal and may sequentially output the latched digital signal to the processor 200. The buffer 140 may include a memory for latching the digital signal and a sense amplifier for amplifying the digital signal.

[0061] The row driver 150 may drive a plurality of unit pixels included in the pixel array 110 in response to an output signal of the timing generator 160 .

[0062] For example, the row driver 150 may generate a selection signal to select any one row line. In addition, the row driver 150 may generate a signal (eg, a transfer transistor driving signal, a reset transistor driving signal, a selection transistor driving signal, etc.) to drive a transistor included in a unit pixel.

[0063] The timing generator 160 may control the row driver 150 so that the pixel array 110 may accumulate charges by absorbing light, may temporarily store the accumulated charges, or may output an electrical signal corresponding to the stored charges to the outside of the pixel array 110 .

[0064] The timing generator 160 may control the correlated double sampler (CDS) 120 to sample and hold the electrical signal received from the pixel array 110 .

[0065] The control register 170 may generate control signals that control the buffer 140 , the timing generator 160 , and the ramp signal generator 180 based on signals received from the processor 200 .

[0066] The ramp signal generator 180 may generate a reference signal that enables an analog-to-digital converter (ADC) 130 to detect a signal in response to a control signal received from the timing generator 160 .

[0067] The processor 200 may receive an input signal output from the buffer 140 and generate image data or phase difference data based on the received input signal. As described above, the processor 200 may use the image data to send a control signal for the aperture driver 340. In addition, the processor 200 may use the phase difference data to send a control signal for the lens driver 320.

[0068] In the following description, an operation mode in which the processor 200 generates phase difference data may be referred to as a first mode, and another operation mode in which the processor 200 generates image data may be referred to as a second mode.

[0069] In the first mode, the processor 200 may generate phase difference data of the external object (S) using signals generated by some unit pixels sharing one microlens among a plurality of unit pixels included in a pixel group.

[0070] Some unit pixels sharing one microlens are disposed adjacent to each other in a row direction or a column direction of the pixel array 110 , and include at least a portion of one microlens.

[0071] For example, it may be assumed that a predetermined number of pixel groups are disposed above the pixel array, each pixel group including two unit pixels sharing a single microlens. In addition, it may be assumed that two unit pixels sharing a single microlens are arranged adjacent to each other in the row direction of the pixel array.

[0072] The processor 200 may calculate a signal generated by a pixel located on the left side of the center point of the pixel group, and use the calculated signal to generate first phase data of the object (S). Similarly, the processor 200 may calculate a signal generated by a pixel located on the right side of the center point of the pixel group, and use the calculated signal to generate second phase data of the object (S).

[0073] If the distance between the lens 310 and the object (S) is considered as a "focus position", the incident light that has passed through one microlens and reaches the unit pixel may have the same size. Therefore, the signals detected by the unit pixels sharing one microlens may have the same size. Therefore, when the distance between the lens 310 and the object (S) satisfies the focus position, the first phase data and the second phase data generated by the processor 200 may be the same as each other.

[0074] When the distance between the lens 310 and the object (S) does not satisfy the focus position, the incident light beams that have passed through one microlens and reached the unit pixel may have different intensities (e.g., sizes) from each other. Therefore, light of different intensities may reach the corresponding unit pixel after passing through one microlens. This is because the paths along which the incident light beams reach the unit pixel are different from each other. As a result, the signals respectively detected by the unit pixels sharing one microlens may have different intensities.

[0075] In this case, the first phase data and the second phase data are different in a predetermined phase. Therefore, there is a phase difference between the first phase data and the second phase data.

[0076] If the distance between the lens 310 and the object (S) does not satisfy the focus position, the processor 200 may calculate a phase difference between the first phase data and the second phase data and generate phase difference data.

[0077] The processor 200 may use the above signals to generate phase difference data, and may provide a control signal to the lens driver 320 based on the phase difference data, so that the control signal may be used to adjust the distance between the object (S) and the lens 310 and the distance between the pixel array 110 and the lens 310.

[0078] Image data may be generated in response to light incident from a subject (S) to the image sensor 100, and may be used as a signal for adjusting the aperture 330. In addition, the processor 200 may acquire a high dynamic range (HDR) image by calculating image data acquired from a plurality of unit pixels.

[0079] The processor 200 may receive the output signal of the buffer 140 and may generate image data during the second mode using the received signal.

[0080] The processor 200 may generate a plurality of image data of the external object (S) using signals respectively generated by unit pixels included in the pixel groups.

[0081] In the second mode, the processor 200 may generate image data using signals generated by two unit pixels sharing one microlens. In addition, in the second mode, the processor 200 may generate image data using signals generated by unit pixels having different light receiving areas (regions).

[0082] The following will refer to Figure 2 A detailed description is given of the second mode for generating image data.

[0083] When a plurality of image data are generated using signals generated by unit pixels included in one pixel group, the plurality of image data may correspond to different illumination environments. Therefore, the processor 200 may generate a high dynamic range (HDR) image by using (eg, synthesizing or calculating) the plurality of image data.

[0084] In addition, the processor 200 may perform various image signal processing for improving image quality, such as noise correction (or noise removal) of image information, interpolation between adjacent pixels, and the like.

[0085] although Figure 1 The processor 200 is shown as being located outside the image sensor 100, but other implementations are possible. For example, the processor 200 may be located inside the image sensor 100 or may be located separately outside the image sensing device ISD.

[0086] Figure 2 is a perspective diagram illustrating an example of a pixel array 410 based on some implementations of the disclosed technology.

[0087] Reference Figure 2 , the pixel array 410 may include a first pixel group PG1, a second pixel group PG2, a third pixel group PG3, and a fourth pixel group PG4. Each of the pixel groups PG1, PG2, PG3, and PG4 may include a first unit pixel PX1, a second unit pixel PX2, a third unit pixel PX3, and a fourth unit pixel PX4. The pixel array 410 may have a specific structure in which the first pixel group PG1, the second pixel group PG2, the third pixel group PG3, and the fourth pixel group PG4 are repeatedly arranged.

[0088] Unit pixels PX1, PX2, PX3, and PX4 included in one pixel group PG1, PG2, PG3, or PG4 may be arranged in a (2×2) matrix over the pixel array 410. Therefore, each of the pixel groups PG1, PG2, PG3, and PG4 may include two rows and two columns.

[0089] In each pixel group PG1, PG2, PG3 or PG4, a row located above the center of each pixel group PG1, PG2, PG3 or PG4 may be referred to as a first row, and a row located below the center of each pixel group PG1, PG2, PG3 or PG4 may be referred to as a second row. In addition, a column located to the left of the center of each pixel group PG1, PG2, PG3 or PG4 may be referred to as a first column, and a column located to the right of the center of each pixel group PG1, PG2, PG3 or PG4 may be referred to as a second column.

[0090] In each pixel group PG1, PG2, PG3 or PG4, when two unit pixels included in the same pixel group and adjacent to each other in the row direction of the pixel group share the first microlens ML1, a unit pixel located on the left side of the center of each pixel group PG1, PG2, PG3 or PG4 may be referred to as a first unit pixel PX1, and a unit pixel located on the right side of the center of each pixel group PG1, PG2, PG3 or PG4 may be referred to as a second unit pixel PX2.

[0091] In other implementations of the disclosed technology, the first unit pixel PX1 and the second unit pixel PX2 may be arranged along a direction other than the row direction of the pixel array 410 .

[0092] In an example in which two unit pixels included in the same pixel group and adjacent to each other in the column direction of the pixel array 410 share the first microlens ML1, a unit pixel located on the upper side of the center of each pixel group PG1, PG2, PG3 or PG4 may be referred to as a first unit pixel PX1, and a unit pixel located on the lower side of the center of each pixel group PG1, PG2, PG3 or PG4 may be referred to as a second unit pixel PX2.

[0093] In addition, among the remaining unit pixels other than the first unit pixel PX1 and the second unit pixel PX2, one unit pixel having a relatively small light receiving area may be referred to as a third unit pixel PX3, and one unit pixel having a relatively large light receiving area may be referred to as a fourth unit pixel PX4. In one pixel group PG_A, PG_B, PG_C, or PG_D, the third unit pixel PX3 and the fourth unit pixel PX4 may be interchanged as needed. The light receiving area of ​​each unit pixel may refer to an area through which incident light may pass. The light receiving area may correspond to a portion of the entire area of ​​each unit pixel.

[0094] In some implementations of the disclosed technology, two unit pixels adjacent to each other in a row direction of each pixel group may share the first microlens ML1 .

[0095] In pixel groups adjacent to each other in the row direction of the pixel array 410, the first unit pixel (PX1) and the second unit pixel (PX2) may be disposed in different rows of the pixel array 410. Therefore, in pixel groups adjacent to each other in the row direction of the pixel array 410, the first microlenses (ML1) may be disposed in different rows of the pixel array 410.

[0096] For example, the first unit pixel PX1 and the second unit pixel PX2 included in the first pixel group PG1 may be disposed in a first row of the first pixel group PG1 , and the first unit pixel PX1 and the second unit pixel PX2 included in the second pixel group PG2 may be disposed in a second row of the second pixel group PG2 .

[0097] In each pixel group adjacent to each other in the column direction of the pixel array 410, the relative positions of the rows in which the first unit pixel (PX1) and the second unit pixel (PX2) are arranged in the corresponding pixel group may be the same. Therefore, in each pixel group adjacent to each other in the column direction of the pixel array 410, the relative positions of the rows in which the first microlens (ML1) is arranged in the corresponding pixel group may be the same.

[0098] For example, the first unit pixel PX1 and the second unit pixel PX2 included in the first pixel group PG1 may be disposed in the first row of the first pixel group PG1. In addition, the first unit pixel PX1 and the second unit pixel PX2 included in the third pixel group PG3 may be disposed in the first row of the third pixel group PG3.

[0099] In other implementations of the disclosed technology, two unit pixels adjacent to each other in the column direction of each pixel group may share a first microlens.

[0100] In pixel groups adjacent to each other in the column direction of the pixel array, first unit pixels and second unit pixels included in different pixel groups in the adjacent pixel groups may be arranged in different columns. Therefore, in pixel groups adjacent to each other in the column direction of the pixel array, first microlenses arranged in the adjacent pixel groups in the column direction of the adjacent pixel groups may be arranged in different columns.

[0101] For example, the first unit pixel and the second unit pixel included in the first pixel group may be disposed in a first column of the first pixel group, and the first unit pixel and the second unit pixel included in the second pixel group may be disposed in a second column of the second pixel group.

[0102] In each pixel group adjacent to each other in the row direction of the pixel array, the relative positions of the columns in which the first unit pixel and the second unit pixel are arranged in the corresponding pixel group may be the same. Therefore, in each pixel group adjacent to each other in the row direction of the pixel array, the relative positions of the columns in which the first microlenses are arranged in the corresponding pixel group may be the same.

[0103] For example, the first unit pixel and the second unit pixel included in the first pixel group may be disposed in a first column of the first pixel group, and the first unit pixel and the second unit pixel included in the third pixel group may be disposed in a first column of the third pixel group.

[0104] The pixel array 410 may include a microlens array 420 , a filter array 430 , and a light shielding structure array 440 .

[0105] The microlens array 420 may include a plurality of microlenses ML1 , ML2 , and ML3 . The microlenses ML1 , ML2 , and ML3 may enable light incident on the pixel array 410 to be guided to a photoelectric conversion element (not shown) disposed below the microlens array 420 .

[0106] As described above, each of the first unit pixel PX1 and the second unit pixel PX2 included in the same pixel group and adjacent to each other in the row or column direction of the pixel array 410 may include at least a portion of the first microlens ML1. In this case, at least a portion of the first microlens ML1 may be formed to overlap the first unit pixel PX1 and the second unit pixel PX2.

[0107] Each of the first unit pixel PX1 and the second unit pixel PX2 may generate a signal corresponding to incident light that has reached a photoelectric conversion element (not shown) after passing through the first microlens ML1 and the filter.

[0108] like Figure 1 As shown, the first microlens ML1 is formed to overlap the first unit pixel PX1 and the second unit pixel PX2. As a result, when the lens 310 is not located at the focusing position, a first path of incident light that has reached the photoelectric conversion element (not shown) of the first unit pixel PX1 is different from a second path of incident light that has reached the photoelectric conversion element (not shown) of the second unit pixel PX2.

[0109] Due to the above-described path difference, a difference may occur between a first signal generated by the first unit pixel PX1 in response to incident light and a second signal generated by the second unit pixel PX2 in response to incident light.

[0110] In the first mode for generating image data, the processor 200 may generate not only the first phase data obtained by calculating the signal generated from the first unit pixel (PX1) of the pixel groups PG1, PG2, PG3, and PG4, but also the second phase data obtained by calculating the signal generated from the second unit pixel (PX2) of the pixel groups PG1, PG2, PG3, and PG4. The processor 200 may generate phase difference data by calculating the first phase data and the second phase data.

[0111] The processor 200 may output a control signal for the lens driver 320 using the phase difference data, thereby performing a phase difference detection auto focusing (PDAF) function.

[0112] In the second mode for generating phase difference data, the processor 200 may generate image data using a first signal generated by the first unit pixel PX1 and a second signal generated by the second unit pixel PX2 .

[0113] In the second mode, when the first unit pixel PX1 and the second unit pixel PX2 are included in one pixel group PG1, PG2, PG3 or PG4, the processor 200 may perform binning of the first signal generated by the first unit pixel PX1 and the second signal generated by the second unit pixel PX2. Here, the first unit pixel PX1 and the second unit pixel PX2 may share one microlens.

[0114] The merging of signals may include obtaining data of at least one pixel by summing or averaging output signals of adjacent pixels.

[0115] For example, when the first unit pixel PX1 and the second unit pixel PX2 are included in the first pixel group PG1, an average value of a signal generated by the first unit pixel PX1 included in the first pixel group PG1 and a signal generated by the second unit pixel PX2 may correspond to an average value of incident light applied to the first unit pixel PX1 and incident light applied to the second unit pixel PX2.

[0116] Therefore, the processor 200 may generate image data of the object (S) using an average value of signals generated by the first and second unit pixels PX1 and PX2 included in each of the pixel groups PG1 , PG2 , PG3 , and PG4 and sharing one first microlens ML1 .

[0117] In the second mode, when the processor 200 generates image data of the object (S) using an average value of a signal generated by the first unit pixel PX1 and a signal generated by the second unit pixel PX2 , the generated image data may be considered as first image data.

[0118] In the second mode, the processor 200 may calculate signals generated by the first unit pixel PX1 and the second unit pixel PX2 for each pixel group PG1 , PG2 , PG3 , or PG4 .

[0119] The third unit pixel PX3 and the fourth unit pixel PX4 may include a second microlens ML2 and a third microlens ML3, respectively. In some implementations, the second microlens ML2 and the third microlens ML3 may have the same shape. In addition, the first microlens ML1 may be formed to be higher than each of the second microlens ML2 and the third microlens ML3.

[0120] When the first microlens ML1 is formed to be higher than each of the second microlens ML2 and the third microlens ML3, the amount of incident light applied to the first unit pixel PX1 and the second unit pixel PX2 may be greater than the amount of incident light applied to the third unit pixel PX3 or the fourth unit pixel PX4. In other words, the sensitivity to the incident light applied to the respective unit pixels PX1, PX2, PX3, and PX4 may be changed according to the shapes of the microlenses.

[0121] In the second mode, the processor 200 may generate the second image data based on the signal generated by the third unit pixel. In addition, the processor 200 may generate the third image data based on the signal generated by the fourth unit pixel (PX4).

[0122] The filter array 430 may be formed under the micro lens array 420. The filter array 430 may include a plurality of filters R, G, and B.

[0123] The filters R, G, and B may enable incident light guided by the microlens array 420 to selectively pass according to the wavelength of the incident light.

[0124] Among the filters included in the filter array 430, the filter configured to pass red light may be referred to as a first filter (R), the filter configured to pass green light may be referred to as a second filter (G), and the filter configured to pass blue light may be referred to as a third filter (B).

[0125] The first to third filters R, G, and B may be arranged in a quad-Bayer pattern over the filter array 430 .

[0126] The quad Bayer pattern may refer to an extension of the Bayer pattern. The Bayer pattern may refer to a pattern in which one first filter (R), two second filters (G), and one third filter (B) are arranged in a matrix and the two second filters (G) are arranged in a diagonal direction.

[0127] The quad Bayer pattern may refer to a pattern in which the first filters (R) constitute a (2×2) matrix, the second filters (G) constitute a (2×2) matrix, and the third filters (B) constitute a (2×2) matrix, such that the 2×2 matrix composed of the respective filters may constitute a Bayer pattern.

[0128] Unit pixels included in the same pixel group may include the same filter R, G, or B. For example, all unit pixels PX1 , PX2 , PX3 , and PX4 included in the first pixel group PG1 may include the second filter (G).

[0129] The light shielding structure array 440 may be used to reduce crosstalk between adjacent unit pixels PX1, PX2, PX3, and PX4 and adjust the amount of received light. The light shielding structure array 440 may include a metal such as tungsten (W).

[0130] Despite Figure 2 4. The light shielding structure array 440 is shown separately from the filter array 430, but other implementations are possible. In some implementations, the filter array 430 may overlap with the light shielding structure array 440 and the light shielding structure array 440 may be inserted into a predetermined area of ​​the filter array 430.

[0131] For example, one surface of the light shielding structure array 440 may be formed at the same vertical position as one surface of a semiconductor substrate (not shown) on which the filter array 430 and the photoelectric conversion element (not shown) are formed. The filter array 430 may overlap with another surface of the light shielding structure array 440.

[0132] The light receiving regions of the unit pixels PX1, PX2, PX3, and PX4 may have a size based on the shape of the light shielding structure array 440. When the light receiving regions of the unit pixels PX1, PX2, PX3, and PX4 have different sizes, the sensitivity of each of the unit pixels PX1, PX2, PX3, and PX4 receiving incident light may also be different.

[0133] The light shielding structure array 440 may include a first light shielding structure G1 and a second light shielding structure G2 .

[0134] The first light shielding structure G1 may be formed along an outer edge of the third unit pixel PX3. The first light shielding structure G1 may optically isolate the third unit pixel PX3 from adjacent unit pixels.

[0135] The second light shielding structure G2 may be formed along an outer edge of the fourth unit pixel PX4. The second light shielding structure G2 may optically isolate the fourth unit pixel PX4 from adjacent unit pixels.

[0136] The first light shielding structure G1 may have a greater width than the second light shielding structure G2. When the first light shielding structure G1 is formed to have a greater width than the second light shielding structure G2, the third unit pixel PX3 may have a smaller light receiving area than the fourth unit pixel PX4.

[0137] When using a unit pixel with a smaller light receiving area, the unit pixel has lower sensitivity to incident light, so that the size of the output signal of the unit pixel reacting to the incident light can be lower than the size of the output signal of another unit pixel with a larger light receiving area.

[0138] The third unit pixel PX3 and the fourth unit pixel PX4 included in the first pixel group PG1 are formed to have light receiving areas of different sizes so that the sensitivities of the third unit pixel PX3 and the fourth unit pixel PX4 may be different, which enables signals of different sizes to be obtained from the third unit pixel PX3 and the fourth unit pixel PX4.

[0139] The processor 200 may generate a plurality of image data using a plurality of signals corresponding to different exposure levels of incident light, and may generate a high dynamic range (HDR) image by synthesizing or calculating the generated plurality of image data. In conventional technology, in order to obtain a high dynamic range (HDR) image, a plurality of frames corresponding to different exposure levels of incident light may be required. Here, the term "frame" may refer to or include an image obtained by a single detection operation of detecting an output signal of a unit pixel included in a pixel array, and thus a plurality of detection operations are required to obtain a plurality of frames corresponding to different exposure levels of incident light.

[0140] Unlike conventional techniques that require multiple detection operations, an image sensing device based on some implementations of the disclosed technology can detect signals of multiple unit pixels included in a pixel array through only a single detection operation, and generate signals corresponding to different exposure levels of incident light when receiving signals detected by multiple unit pixels included in one pixel group. As a result, an image sensing device lSD based on some implementations of the disclosed technology can acquire a high dynamic range (HDR) image using only one frame.

[0141] In some implementations, a light shielding structure may not be formed in each of the first unit pixel PX1 and the second unit pixel PX2. When a light shielding structure is not formed in each of the first unit pixel PX1 and the second unit pixel PX2, a light receiving area of ​​a sufficient size for the first unit pixel PX1 and the second unit pixel PX2 may be obtained.

[0142] In addition, the size of the light receiving area of ​​the first unit pixel PX1 may be the same as that of the light receiving area of ​​the second unit pixel PX2.

[0143] As described above, in each of the pixel groups PG1, PG2, PG3, and PG4, the first unit pixel (PX1) and the second unit pixel (PX2) included in the pixel groups adjacent to each other in the row direction of the pixel array 410 may be arranged in different rows. In each of the pixel groups adjacent to each other in the column direction of the pixel array 410, the relative positions of the rows in which the first unit pixel (PX1) and the second unit pixel (PX2) are arranged in the corresponding pixel group may be the same. Therefore, the first unit pixel PX1 may be located between the third unit pixel (PX3) and the second unit pixel PX2 may be located between the fourth unit pixel (PX4).

[0144] Therefore, although a light shielding structure is not formed in each of the first and second unit pixels PX1 and PX2 , the first and second unit pixels PX1 and PX2 may be optically isolated from adjacent unit pixels by the first and second light shielding structures G1 and G2 .

[0145] FIG. 3A to FIG. 3D 2 is a top view showing various examples of pixel groups PG_A, PG_B, PG_C, and PG_D based on some implementations of the disclosed technology. For convenience of description, filters R, G, and B will be omitted herein for simplicity.

[0146] In the pixel groups PG_A, PG_B, PG_C and PG_D each including first to fourth unit pixels PX1, PX2, PX3 and PX4 arranged in a (2×2) matrix, when two unit pixels included in the same pixel group and adjacent to each other in a row direction of each of the pixel groups PG_A, PG_B, PG_C and PG_D share the first microlens ML1, one unit pixel located on the left side of the center of each of the pixel groups PG_A, PG_B, PG_C and PG_D may be referred to as a first unit pixel PX1, and one unit pixel located on the right side of the center of each of the pixel groups PG_A, PG_B, PG_C and PG_D may be referred to as a second unit pixel PX2.

[0147] In other implementations, when two unit pixels adjacent to each other in the column direction of each of the pixel groups PG_A, PG_B, PG_C, and PG_D share the first microlens ML1, a unit pixel located on the upper side of the center of each of the pixel groups PG_A, PG_B, PG_C, and PG_D may be referred to as a first unit pixel PX1, and a unit pixel located on the lower side of the center of each of the pixel groups PG_A, PG_B, PG_C, and PG_D may be referred to as a second unit pixel PX2.

[0148] In addition, one unit pixel having a smaller light receiving area among the remaining unit pixels except the first unit pixel PX1 and the second unit pixel PX2 may be referred to as a third unit pixel PX3, and one unit pixel having a larger light receiving area among the remaining unit pixels except the first unit pixel PX1 and the second unit pixel PX2 may be referred to as a fourth unit pixel PX4.

[0149] In a specific pixel group PG_A, PG_B, PG_C, or PG_D, positions of the third unit pixel PX3 and the fourth unit pixel PX4 may be interchanged. The second microlens ML2 may overlap the third unit pixel PX3, and the third microlens ML3 may overlap the fourth unit pixel PX4.

[0150] Figure 3A The first to fourth unit pixels PX1, PX2, PX3, and PX4 included in the pixel group A (PG_A) shown in FIG. Figure 2 The first pixel group PG1 shown is arranged in substantially the same manner.

[0151] The pixel group A (PG_A) may further include a third light shielding structure G3 formed along outer edges of the first and second unit pixels PX1 and PX2. The third light shielding structure G3 may optically isolate the first and second unit pixels PX1 and PX2 from adjacent unit pixels.

[0152] Since the third light shielding structure G3 is formed along the outer edges of the first and second unit pixels PX1 and PX2 , a light shielding structure may not be formed between the first and second unit pixels PX1 and PX2 .

[0153] When the light shielding structure is formed between the first unit pixel PX1 and the second unit pixel PX2 , incident light incident near a boundary between the first unit pixel PX1 and the second unit pixel PX2 may be reflected by the light shielding structure.

[0154] When the light shielding structure formed between the first unit pixel PX1 and the second unit pixel PX2 reflects incident light, distortion may occur in each of the signal generated by the first unit pixel PX1 and the signal generated by the second unit pixel PX2. Therefore, when the processor 200 generates phase difference data using the above signals, it may be difficult for the image sensor to perform correct auto focusing.

[0155] The first light shielding structure G1 may have a first width W1 in the row direction (ROW) and the column direction (COLUMN) of the pixel group A (PG_A), but the scope of the disclosed technology is not limited to this. It should be noted that the first light shielding structure G1 may have different widths in the row direction (ROW) and the column direction (COLUMN) of the pixel group A (PG_A) as needed.

[0156] The second light shielding structure G2 may have a second width W2 in the row direction (ROW) and the column direction (COLUMN) of the pixel group A (PG_A). The third light shielding structure G3 may have a third width W3 in the row direction (ROW) and the column direction (COLUMN) of the pixel group A (PG_A).

[0157] In some implementations, the size of the light receiving area of ​​each of the unit pixels PX1 , PX2 , PX3 , and PX4 may be adjusted by adjusting the first width W1 , the second width W2 , and the third width W3 .

[0158] For example, the first width W1 may be greater than the second width W2. Since the first width W1 is greater than the second width W2, the size of the light receiving area of ​​the third unit pixel PX3 may be smaller than that of the fourth unit pixel PX4.

[0159] When the third unit pixel PX3 has a smaller light receiving area, the sensitivity of the third unit pixel PX3 reacting to the same incident light may be lower than the sensitivity of the fourth unit pixel PX4 reacting to the same incident light.

[0160] Therefore, image data based on a signal generated by the third unit pixel PX3 (ie, second image data) may have lower sensitivity than image data based on a signal generated by the fourth unit pixel PX4 (ie, third image data).

[0161] In addition, the third width W3 may be smaller than the second width W2. As described above, since the first microlens ML1 is formed to have a height higher than each of the second microlens ML2 and the third microlens ML3 and the third width W3 is smaller than the second width W2, the sensitivity of each of the first unit pixel PX1 and the second unit pixel PX2 may be higher than the sensitivity of the third unit pixel PX3 or the fourth unit pixel PX4.

[0162] If the sensitivity of each of the first unit pixel PX1 and the second unit pixel PX2 becomes high, a signal may be detected in the first unit pixel PX1 and the second unit pixel PX2 even when the intensity level of incident light is low.

[0163] As a result, although the intensity of incident light is at a low level, the processor 200 may perform the operation of the first mode.

[0164] In addition, when the sensitivity of each of the first unit pixel PX1 and the second unit pixel PX2 becomes higher than the sensitivity of the third unit pixel PX3 or the fourth unit pixel PX4, the first image data generated by the processor 200 operating in the second mode (i.e., image data generated based on the signals generated by the first unit pixel PX1 and the second unit pixel PX2) may be image data having a higher illumination environment than each of the second image data generated based on the signal generated by the third unit pixel PX3 and the third image data generated based on the signal generated by the fourth unit pixel PX4.

[0165] The processor 200 may generate an HDR image by synthesizing or calculating the first image data, the second image data, and the third image data.

[0166] exist Figure 3B In the pixel group B (PG_B) shown, the first unit pixel PX1 and the second unit pixel PX2 may be arranged in the column direction of the pixel array. Since the first unit pixel PX1 and the second unit pixel PX2 are arranged in the column direction of the pixel array, the third unit pixel PX3 and the fourth unit pixel PX4 may also be arranged in the column direction of the pixel array.

[0167] Figure 3B The remaining characteristics other than the arrangement of the unit pixels PX1, PX2, PX3, and PX4 in the pixel group B (PG_B) shown (eg, the shape of the light shielding structure, etc.) may be structurally different from those in FIG. Figure 3A Those of the pixel group A (PG_A) shown are substantially identical.

[0168] Since the first unit pixel PX1 and the second unit pixel PX2 are arranged in a column direction of the pixel array, the processor 200 may acquire phase difference data in the column direction upon receiving signals generated by the first unit pixel PX1 and the second unit pixel PX2 .

[0169] Figure 3C The pixel group C (PG_C) and Figure 3D The illustrated pixel group D (PG_D) shows other implementations in which the unit pixels PX1 , PX2 , PX3 , and PX4 are arranged in a pixel group.

[0170] exist Figure 3C In the pixel group C (PG_C) shown, the first unit pixel PX1 and the second unit pixel PX2 may be arranged in the row direction of the pixel array. Since the first unit pixel PX1 and the second unit pixel PX2 are arranged in the row direction of the pixel array, the third unit pixel PX3 and the fourth unit pixel PX4 may also be arranged in the row direction of the pixel array.

[0171] exist Figure 3DIn the pixel group D (PG_D) shown, the first unit pixel PX1 and the second unit pixel PX2 may be arranged in the column direction of the pixel array. Since the first unit pixel PX1 and the second unit pixel PX2 are arranged in the column direction of the pixel array, the third unit pixel PX3 and the fourth unit pixel PX4 may also be arranged in the column direction of the pixel array.

[0172] In some implementations, FIG. 3A to FIG. 3D Four pixel groups among the illustrated pixel groups A, B, C, and D (PG_A, PG_B, PG_C, and PG_D) may be arranged in a (2×2) matrix.

[0173] In addition, the pixel array may have a (2×2) matrix repeated structure.

[0174] For example, pixel group A (PG_A) may be located at the first row and first column of a (2×2) matrix, and pixel group C (PG_C) may be located not only at the first row and second column, but also at the second row and first column of the (2×2) matrix. In addition, pixel group B (PG_B) may be located at the second row and second column of the (2×2) matrix.

[0175] Among the four pixel groups included in the (2×2) matrix (i.e., one pixel group (PG_A), one pixel group (PG_B), and two pixel groups (PG_C)), the first unit pixel PX1 and the second unit pixel PX2 included in the pixel group B (PG_B) are arranged in the column direction of the pixel array, and the processor 200 can obtain phase difference data in the column direction when receiving a signal generated by the pixel group B (PG_B) arranged in the entire pixel array in the first mode.

[0176] In addition, assuming that the filter array included in the pixel array is formed in the above-mentioned quad Bayer pattern, the filter included in each of the pixel group A (PG_A) and the pixel group B (PG_B) may be the second filter (G).

[0177] In the quad Bayer pattern, the number of unit pixels each including the second filter (G) is twice the number of unit pixels each including the first filter (R) or the number of unit pixels each including the third filter (B). As a result, although there is a difference between the signal generated by each of the first unit pixel PX1 and the second unit pixel PX2 of the pixel group B (PG_B) and the signal generated by another pixel group A (PG_A), the processor 200 can generate image data by easily performing interpolation in the second mode.

[0178] Figure 4 is a graph illustrating an example of a response signal to the intensity of incident light applied to each unit pixel included in a pixel group based on some implementations of the disclosed technology.

[0179] Figure 4 is a graph showing pixel signals used to generate image data. In more detail, Figure 4 , an average response (PDAF AVGRESPONSE) of a first signal generated by the first unit pixel PX1 and a second signal generated by the second unit pixel PX2, a third signal response (PX3RESPONSE) generated by the third unit pixel PX3, and a fourth signal response (PX4 RESPONSE) generated by the fourth unit pixel PX4 are shown.

[0180] Among the noise floor (NOISE FLOOR), the floating diffusion (FLOATING DIFFUSION), and the saturation signal (FDSATURATION), the signals generated by the first to fourth unit pixels PX1, PX2, PX3, and PX4 may have valid values. In the first to fourth unit pixels PX1, PX2, PX3, and PX4, the floating diffusion (FLOATING DIFFUSION) and the saturation signal (FD SATURATION) may have the same value.

[0181] The slope of each of the average response (PDAF AVG RESPONSE) of the first and second signals, the third signal response (PX3RESPONSE), and the fourth signal response (PX4 RESPONSE) may be proportional to the sensitivity of the unit pixels PX1, PX2, PX3, and PX4 configured to generate the above signals.

[0182] If each unit pixel has high sensitivity, the floating diffusion (FD) region may be saturated more quickly even when exposed to incident light of low intensity.

[0183] Compared with the fourth signal graph (PX4 RESPONSE), the average response (PDAFAVG RESPONSE) of the first and second signals can reach the floating diffusion saturation signal (FD SATURATION) more quickly. This is because each of the first and second unit pixels PX1 and PX2 has a higher sensitivity than the fourth unit pixel PX4.

[0184] In addition, the lowest intensity of incident light that can be detected by each of the first unit pixel PX1 and the second unit pixel PX2 may be lower than the lowest intensity of incident light that can be detected by the fourth unit pixel PX4 .

[0185] Therefore, when the processor 200 uses an average value of the signal of the first unit pixel PX1 and the signal of the second unit pixel PX2 , the size of the dynamic range of low-intensity incident light may be more extended than an exemplary case of using only the signal of the fourth unit pixel PX4 .

[0186] The processor 200 may acquire high-sensitivity image data using an average signal of the first signal and the second signal. In the high-sensitivity image data, a dark portion of the external object (S) may be more accurately represented than image data obtained using only the fourth signal.

[0187] In addition, when the third signal graph (PX3RESPONSE) is exposed to incident light with a stronger intensity than the fourth signal graph (PX4RESPONSE), the third signal graph (PX3RESPONSE) may reach a floating diffusion saturation signal (FDSATURATION) because the third unit pixel PX3 has a lower sensitivity than the fourth unit pixel PX4 when the size of the light receiving area of ​​the third unit pixel PX3 is smaller than the light receiving area of ​​the fourth unit pixel PX4.

[0188] Therefore, when the processor 200 uses the signal of the third unit pixel PX3 , the size of the dynamic range of incident light having a stronger intensity may be more extended than the exemplary case of using only the signal of the fourth unit pixel PX4 .

[0189] The processor 200 may acquire low-sensitivity image data using the third signal. In the low-sensitivity image data, a bright portion of the external object (S) may be more accurately represented than image data obtained using only the signal of the fourth unit pixel PX4.

[0190] The processor 200 uses the average signal of the first and second signals, the third signal, and the fourth signal so that the processor 200 can generate high dynamic range (HDR) image data having a dynamic range (contrast width) more extended than the exemplary case of using only the fourth signal.

[0191] Figure 5 is a diagram showing some implementations based on the disclosed technology. Figure 4 Shown is a graph showing the comparison results between the response average (RESPONSEAVG) corresponding to the average of the signal responses (PDAF AVGRESPONSE, PX3 RESPONSE and PX4 RESPONSE) and the intensity of the incident light.

[0192] Figure 5 Improvements in the gradient characteristics of an image sensing device ISD based on some implementations of the disclosed technology are shown.

[0193] The term "gradation" may refer to the contrast difference between light and dark portions of image data in representing the contrast of such image data. That is, good gradation may indicate that there is little contrast difference between light and dark portions of the image data.

[0194] Figure 5 An exponential response (LOG RESPONSE) and a linear response (LINEAR RESPONSE) compared to a response average (RESPONSE AVG) are shown exemplarily.

[0195] LINEAR RESPONSE Figure 4 The average response (PDAFAVG RESPONSE) of the first and second signals shown is the same.

[0196] The exponential response (LOG RESPONSE) may schematically illustrate an exemplary response of a unit pixel having an ideal response characteristic based on the intensity of incident light.

[0197] The slope of the average response (RESPONSE AVG) may change not only at a first point (PX1, PX2 SATURATION) where the first and second unit pixels PX1 and PX2 are saturated, but also at a second point (PX4 SATURATION) where the fourth unit pixel PX4 is saturated.

[0198] The average response (RESPONSE AVG) indicates an average of responses having different slopes, so that the average response (RESPONSE AVG) may have different slopes in respective sections based on the intensity of incident light.

[0199] Therefore, the shape of the average response (RESPONSEAVG) may be more similar to an exponential response (LOG RESPONSE) than a linear response (LINEAR RESPONSE).

[0200] As the similarity between the average response (RESPONSE AVG) and the exponential response (LOG RESPONSE) becomes higher, the shape of the average response (RESPONSE AVG) may be similar to the ideal response of the unit pixel and may smoothly represent pixel signal changes in response to varying intensity of incident light.

[0201] Therefore, by additionally applying the third signal and the average signal of the first signal and the second signal to the process of generating image data, the image sensing device ISD based on some implementations of the disclosed technology can improve the gradient characteristics of the image data.

[0202] As is apparent from the above description, an image sensing device based on some implementations of the disclosed technology can perform a phase difference detection autofocus (PDAF) function. In addition, the image sensing device can generate a high dynamic range (HDR) image using multiple signals generated by one pixel group.

[0203] An image sensing device based on some implementations of the disclosed technology may use multiple signals generated by a pixel group, and may perform signal detection only once with respect to each unit pixel included in a pixel array, so that a high dynamic range (HDR) image may be generated and a higher quality HDR image may be obtained.

[0204] Those skilled in the art will appreciate that the disclosed technology can be implemented in specific ways other than those described herein. In addition, claims that are not explicitly stated in the appended claims may be stated as a combination of embodiments, or may be included as new claims through subsequent amendments after filing an application.

[0205] Although a number of exemplary embodiments have been described, it should be understood that modifications to the disclosed embodiments and other embodiments are contemplated based on what is described and / or illustrated in this patent document.

[0206] CROSS-REFERENCE TO RELATED APPLICATIONS

[0207] This patent document claims priority to and the benefit of Korean Patent Application No. 10-2020-0124439, filed on September 25, 2020, the disclosure of which is incorporated by reference in its entirety as a part of the disclosure of this patent document.

Claims

1. An image sensing device, comprising: a plurality of pixel groups, each pixel group including a first unit pixel, a second unit pixel, a third unit pixel, and a fourth unit pixel that respond to incident light and generate an electrical signal, and wherein each of the first unit pixel, the second unit pixel, the third unit pixel, and the fourth unit pixel of the pixel group includes a filter operable to transmit incident light corresponding to the same color, wherein the first unit pixel and the second unit pixel included in the pixel group are arranged adjacent to each other and share a first microlens, and wherein the size of the light receiving area of ​​the third unit pixel of the pixel group is smaller than the size of the light receiving area of ​​the fourth unit pixel of the pixel group, The third unit pixel and the fourth unit pixel include a second microlens and a third microlens, respectively, and Wherein, the second microlens and the third microlens have the same shape, Wherein, each of the pixel groups further includes: a first light shielding structure formed along an outer edge of the third unit pixel; a second light shielding structure formed along an outer edge of the fourth unit pixel; and a third light shielding structure formed along outer edges of the first unit pixel and the second unit pixel, wherein the width of the first light shielding structure is greater than the width of the second light shielding structure, the width of the third light shielding structure is less than the width of the second light shielding structure, and The first microlens is formed to have a height higher than that of the second microlens or the third microlens.

2. The image sensing device according to claim 1, wherein: The optical filter is any one of a first optical filter that selectively passes red light, a second optical filter that selectively passes green light, or a third optical filter that selectively passes blue light.

3. The image sensing device according to claim 1, wherein: A size of a light receiving area of ​​the first unit pixel of the pixel group is the same as a size of a light receiving area of ​​the second unit pixel of the pixel group.

4. An image sensing device, comprising: A pixel array including a plurality of pixel groups, each pixel group including unit pixels arranged in a (2×2) matrix, the unit pixels responding to incident light and generating a signal corresponding to the incident light; as well as a processor electrically coupled to the pixel group and processing the signal generated by the unit pixel included in the pixel group, Each pixel group further includes: a first unit pixel, a second unit pixel, a third unit pixel, and a fourth unit pixel, wherein the first unit pixel, the second unit pixel, the third unit pixel, and the fourth unit pixel include filters that transmit incident light of the same color; a first microlens, the first microlens being arranged to overlap the first unit pixel and the second unit pixel, and The size of the light receiving area of ​​the third unit pixel is smaller than the size of the light receiving area of ​​the fourth unit pixel. wherein the processor generates phase difference data indicating a phase difference between a first path of the incident light reaching the first unit pixel and a second path of the incident light reaching the second unit pixel, The third unit pixel and the fourth unit pixel include a second microlens and a third microlens, respectively, and wherein the second microlens and the third microlens have the same shape, and Wherein, each of the pixel groups further includes: a first light shielding structure formed along an outer edge of the third unit pixel; a second light shielding structure formed along an outer edge of the fourth unit pixel; and a third light shielding structure formed along outer edges of the first unit pixel and the second unit pixel; wherein the width of the first light shielding structure is greater than the width of the second light shielding structure, the width of the third light shielding structure is less than the width of the second light shielding structure, and The first microlens is formed to have a height higher than that of the second microlens or the third microlens.

5. The image sensing device according to claim 4, wherein: The processor operates to generate first image data based on the signals generated by the first unit pixel and the second unit pixel.

6. The image sensing device according to claim 5, wherein: The processor also generates second image data based on the signal generated by the third unit pixel, and generates third image data based on the signal generated by the fourth unit pixel.

7. The image sensing device according to claim 6, wherein: The processor generates a high dynamic range (HDR) image using the first image data, the second image data, and the third image data.

Images