Image sensing device

Abstract

The present application relates to an image sensing device. An image sensing device is provided, which includes a pixel array. The pixel array includes one or more phase difference detection pixel groups, each phase difference detection pixel group being composed of a plurality of phase difference detection pixels. Each phase difference detection pixel includes a photoelectric conversion element. Among them, the phase difference detection pixel group includes a light shielding pattern, and the light shielding pattern is configured to provide a light receiving region having a bracket-shaped planar shape for each of two or more phase difference detection pixels.

Description

Technical Field

[0001] The technologies and implementations disclosed in this patent document generally relate to image sensing devices. Background Art

[0002] Image sensing devices are used in electronic devices to convert optical images into electrical signals. Recent developments in the computer and communication industries have led to an increased demand for higher-performance image sensing devices in various devices such as smart phones, digital cameras, portable video cameras, personal communication systems (PCS), gaming consoles, security cameras, medical micro cameras, robots, and infrared sensing devices.

[0003] In terms of how to process image sensing signals, CMOS image sensing devices have advantages over other types of image sensors. In addition, CMOS image sensing devices are manufactured using CMOS manufacturing technology, so CMOS image sensors and other signal processing circuits can be integrated on a single chip, enabling the production of miniaturized CMOS image sensing devices and low-power image sensors at a lower cost. Summary of the Invention

[0004] Embodiments of the disclosed technology relate to an image sensing device that can simultaneously perform phase difference detection autofocus (PDAF) and single-trigger high dynamic range (HDR) imaging by using pixel signals generated by a plurality of unit pixels included in a pixel group.

[0005] In an embodiment, an image sensing device is provided that includes a pixel array including one or more phase difference detection pixel groups, each phase difference detection pixel group being composed of a plurality of phase difference detection pixels, each phase difference detection pixel including a photoelectric conversion element, wherein the phase difference detection pixel group includes a light-shielding pattern configured to provide a light receiving region having a bracket-shaped planar shape for each of two or more phase difference detection pixels.

[0006] In an embodiment, an image sensing device is provided that includes a pixel array including one or more phase difference detection pixel groups, each phase difference detection pixel group having a first phase difference detection pixel, a second phase difference detection pixel, a third phase difference detection pixel, and a fourth phase difference detection pixel arranged in a 2×2 matrix and each including a photoelectric conversion element, wherein the phase difference detection pixel group includes a light-shielding pattern arranged at the center of the phase difference detection pixel group and configured to provide a first light receiving region, a second light receiving region, a third light receiving region, and a fourth light receiving region each having a bracket-shaped planar shape to the first phase difference detection pixel to the fourth phase difference detection pixel, respectively.

[0007] In an embodiment, an image sensing device is provided that includes a pixel array having one or more phase difference detection pixel groups. Each phase difference detection pixel group includes first, second, third, fourth, fifth, sixth, seventh, eighth, and ninth phase difference detection pixels arranged in a 3×3 matrix and each including a photoelectric conversion element. Among them, the phase difference detection pixel group includes a light-shielding pattern configured to provide a first light reception region, a third light reception region, a seventh light reception region, and a ninth light reception region, each having a bracket-shaped planar shape, to the first, third, seventh, and ninth phase difference detection pixels located at respective corner portions of the phase difference detection pixel group.

[0008] In some embodiments of the disclosed technology, each of two or more unit pixels among a plurality of unit pixels included in one pixel group may include a light reception region having a bracket-shaped planar shape due to the light-shielding pattern. Accordingly, the image sensing device may perform operations on pixel signals generated by one pixel group, thereby simultaneously performing PDAF functions and single-shot HDR imaging functions in horizontal, vertical, and diagonal directions. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 is a diagram illustrating an example of an image sensing device according to an embodiment of the disclosed technology.

[0010] Figure 2 is a perspective view illustrating a part of a pixel array in an image sensing device according to some embodiments of the disclosed technology.

[0011] Figure 3 is a plan view illustrating a phase difference detection pixel group in an image sensing device according to some embodiments of the disclosed technology.

[0012] Figures 4A to 4D is a plan view illustrating an example of a phase difference detection pixel group in an image sensing device according to some embodiments of the disclosed technology.

[0013] Figure 5 is a plan view illustrating an example of a phase difference detection pixel group in an image sensing device according to an embodiment of the disclosed technology. DETAILED DESCRIPTION

[0014] With reference to the accompanying drawings, features of the technology disclosed in this patent document are described by way of examples of an image sensing device.

[0015] Phase difference detection autofocus (PDAF) is an autofocus scheme for automatically adjusting the focus using the phase difference between detected images. Single-shot high dynamic range (HDR) imaging is a scheme capable of creating an HDR image through a single imaging operation.

[0016] The disclosed technology can be implemented in some embodiments to provide an image sensing device having one or more pixels capable of performing both PDAF and single-shot HDR imaging.

[0017] In some implementations, the image sensing device can simultaneously perform PDAF and single-shot HDR imaging by using pixel signals generated by a pixel group including a plurality of unit pixels.

[0018] In some implementations, the pixel array of the image sensing device can include one or more pixel groups, each pixel group including a plurality of unit pixels. At least one of the one or more pixel groups can include a light-shielding pattern and one or more light-receiving regions. The light-shielding pattern can be configured to shield at least a portion of one or more phase difference detection pixels. The one or more light-receiving regions can be configured to allow a limited amount of light to pass through and enter the one or more phase difference detection pixels. In one example, each pixel group can provide a light-shielding pattern and a light-receiving region for two or more unit pixels in the pixel group. The light-receiving region can include an L-shaped structure. In some implementations, the light-receiving region can include a plurality of L-shaped openings.

[0019] Figure 1 is a diagram illustrating an example of an image sensing device according to an embodiment of the disclosed technology. Hereinafter, reference will be made to Figure 1 describe a method for the image sensing device to perform the PDAF function and a method for the image sensing device to perform the single-shot HDR imaging function.

[0020] As Figure 1 shown, an image sensing device ISD according to an embodiment of the disclosed technology can include an image sensor 100, a processor 200, and an imaging unit 300.

[0021] The imaging unit 300 may include components for receiving light. In some implementations, the imaging unit 300 may include a module lens 310, a lens driver 320, a diaphragm 330, and a diaphragm driver 340. In one example, the module lens 310 may include multiple lenses. In another example, the module lens 310 may include a single lens. The lens driver 320 may adjust the position of the module lens 310 based on a control signal from the processor 200. In some implementations, the position of the module lens 310 may be adjusted in a way that adjusts the distance between the module lens 310 and the object S. The diaphragm 330 may be used to adjust the amount of light entering the module lens 310 based on a control signal from the diaphragm driver 340. Changing the amount of light entering the module lens 310 through the diaphragm 330 may cause a change in the amplitude of the signal generated by the image sensor 100.

[0022] The processor 200 may provide a control signal for adjusting the position of the module lens 310 to the lens driver 320, or a control signal for adjusting the value of the diaphragm 330 to the diaphragm driver 340, based on the signal generated by the image sensor 100.

[0023] The image sensor 100 may include a pixel array 110, a CDS (correlated double sampler) 120, an ADC (analog-to-digital converter) 130, a buffer 140, a row driver 150, a timing generator 160, a control register 170, and a ramp signal generator 180.

[0024] In some embodiments of the disclosed technology, the pixel array 110 may include one or more pixel groups. Each pixel group may include multiple unit pixels. For example, a pixel group may include four unit pixels arranged in a 2×2 matrix. The light rays that have passed through the module lens 310 and the diaphragm 330 are incident on the pixel array 110 and converted into electrical signals, and the unit pixels may generate electrical signals (pixel signals) corresponding to the object S. The unit pixels included in the pixel array 110 may generate a current by absorbing photons of light, and the current is supplied to the CDS 120.

[0025] In some implementations, although not shown, each unit pixel included in the pixel array 110 may include a microlens, a color filter, a photoelectric conversion element (e.g., a photodiode), and an interconnection layer. The microlens may focus and concentrate light onto the color filter and the photoelectric conversion element of the pixel array 110. The color filter may selectively transmit incident light that passes through the microlens at a specific wavelength. The photoelectric conversion element may generate photo charges corresponding to the incident light that has passed through the microlens and the color filter. Examples of the photoelectric conversion element may include a photodiode, a phototransistor, a photogate, a pinned photodiode (PPD), or a combination thereof. In the following description, the term "photoelectric conversion element" is used to indicate a photodiode. In some implementations, the photoelectric conversion element may include a vertically stacked N-type impurity region and a P-type impurity region. The photoelectric conversion element may be formed in a semiconductor substrate. For example, the semiconductor substrate may be a P-type semiconductor substrate.

[0026] The interconnection layer may be formed under the photoelectric conversion element. The interconnection layer may include a reset transistor, a transfer transistor, a floating diffusion, a driving transistor, a selection transistor, etc. The reset transistor may be activated in response to a reset signal and reset the voltage of the unit pixel to a predetermined level (e.g., the pixel voltage level). When the reset transistor is activated, the transfer transistor may be activated, thereby resetting the floating diffusion. The transfer transistor may be activated in response to a transfer signal and transfer the charge accumulated in the photoelectric conversion element of each unit pixel to the floating diffusion. The floating diffusion may receive the charge generated by the photoelectric conversion element and convert the received charge into a voltage to accumulate the charge. The driving transistor may have a drain that receives the pixel voltage, and the floating diffusion may be connected to the gate of the driving transistor. The selection transistor may be connected to the source of the driving transistor. The driving transistor may output a current corresponding to the voltage of the floating diffusion connected to the gate of the driving transistor to a signal line through the selection transistor. The selection transistor may be activated in response to a selection signal applied to its gate and output the signal received from the driving transistor to the signal line and the CDS 120.

[0027] A CMOS image sensor can use correlated double sampling (CDS) to remove unwanted pixel offset values by sampling the pixel signal twice to remove the difference between the two samplings. In one example, correlated double sampling (CDS) can remove unwanted pixel offset values by comparing the pixel output voltages obtained before and after the optical signal is incident on the pixel, enabling the pixel output voltage based on the incident light to be measured only. In some implementations of the disclosed technology, CDS 120 can sample and hold the electrical signal provided by pixel array 110. CDS 120 can sample the signal level generated by the incident light and a specific noise level, and output a level corresponding to the difference between the two. ADC 130 can convert the analog signal received from CDS 120 into a digital signal and send the digital signal to buffer 140. Buffer 140 can latch the received digital signal and output the latched signal to processor 200 in sequence. Buffer 140 can include a memory for holding the digital signal and a sense amplifier for amplifying the digital signal. Row driver 150 can activate multiple unit pixels included in pixel array 110 based on the signal from timing generator 160. For example, row driver 150 can generate a signal for selecting one row line among multiple row lines. In addition, row driver 150 can generate a signal for activating the transistors included in the unit pixel. For example, the signal can include a transfer transistor drive signal, a reset transistor drive signal, a select transistor drive signal, etc. Timing generator 160 can control pixel array 110 to accumulate the charge generated by absorbing light or temporarily store the accumulated charge, and control row driver 150 to output the electrical signal based on the stored charge to the outside of pixel array 110. Timing generator 160 can control CDS 120 to sample and hold the electrical signal provided by pixel array 110. Control register 170 can generate control signals for controlling buffer 140, timing generator 160, and ramp signal generator 180 based on the signal received from processor 200. Ramp signal generator 180 can provide a reference signal for controlling ADC 130 to detect the signal under the control of timing generator 160.

[0028] Processor 200 can receive the output signal of buffer 140 and generate image data or phase difference data. As described above, processor 200 can use the generated image data to provide a control signal for aperture driver 340. In addition, processor 200 can use the phase difference data to provide a control signal for lens driver 320.

[0029] In the first mode, processor 200 receives the output signal of buffer 140 and generates phase difference data of object S by using the pixel signals generated by two or more unit pixels selected from among the multiple unit pixels included in the pixel group.

[0030] The processor 200 may generate first phase data of the object S based on pixel signals generated by pixels located on the left and right sides of the center of the pixel group. The first phase data may include a phase difference in the horizontal direction. In addition, the processor 200 may generate second phase data of the object S based on pixel signals generated by pixels located on the top and bottom sides of the center of the pixel group. The second phase data may include a phase difference in the vertical direction. In addition, the processor 200 may generate third phase data of the object S based on pixel signals generated by pixels located in the upper left and lower right of the center of the pixel group or pixels located in the upper right and lower left of the center of the pixel group. That is, the third phase data may include a phase difference in the diagonal direction. The diagonal direction may indicate a direction having a predetermined slope between the vertical direction and the horizontal direction. For example, the diagonal direction may indicate a direction having a slope of ±45° between the vertical direction and the horizontal direction.

[0031] When the distance between the module lens 310 and the object S corresponds to the in-focus position, the incident light rays reaching each unit pixel via one microlens may have the same amplitude. Accordingly, the pixel signals detected by the unit pixels sharing one microlens may have the same amplitude. Accordingly, when the distance between the module lens 310 and the object S corresponds to the in-focus position, the first to third phase data generated by the processor 200 may be the same. However, when the distance between the module lens 310 and the object S does not correspond to the in-focus position, the incident light rays reaching each unit pixel via one microlens may have different amplitudes. This is because path differences may occur between the incident light rays passing through the microlens. Accordingly, the pixel signals detected by the unit pixels sharing one microlens may have different amplitudes. Accordingly, the first to third phase data generated from different signals may also be different and may have different phases.

[0032] When the distance between the module lens 310 and the object S does not correspond to the in-focus position, the processor 200 may generate phase difference data by calculating the phase differences between the first phase data, the second phase data, and the third phase data. The processor 200 may use the signals to generate the phase difference data and provide a control signal to the lens driver 320 based on the phase difference data, thereby adjusting the distance between the object S and the module lens 310 and the distance between the pixel array 110 and the module lens 310.

[0033] Image data may be generated in response to light incident on image sensor 100 from object S, and is used as a control signal for adjusting the value of aperture 330. Processor 200 may obtain a high dynamic range (HDR) image by performing operations on the image data acquired from multiple unit pixels. Specifically, processor 200 may receive the output signal of buffer 140 and generate image data. In the second mode, processor 200 receives the output signal of buffer 140 and generates image data. Processor 200 may generate multiple pieces of image data of object S by using the pixel signals generated by each unit pixel included in the pixel group. During the second mode, processor 200 may use the pixel signals generated by two or more unit pixels sharing one microlens to generate image data. When processor 200 uses the pixel signals generated by each unit pixel included in a single pixel group to generate multiple pieces of image data, the multiple pieces of image data may be image data corresponding to different illuminance environments. Accordingly, processor 200 may generate an HDR image by synthesizing the multiple pieces of image data or performing operations on the multiple pieces of image data.

[0034] In addition to the image generation process, processor 200 may also perform image signal processing for image quality improvement, such as noise correction for image information or interpolation between adjacent pixels. Figure 1 It is illustrated that processor 200 is disposed outside image sensor 100. However, the disclosed technology is not limited thereto. As another example, processor 200 may be disposed inside image sensor 100, or separately disposed outside image sensing device ISD.

[0035] As will be referred to below Figure 2 and Figure 3 discussed, the pixel group may simultaneously perform a single-shot HDR imaging function and a PDAF function in the vertical direction, horizontal direction, and diagonal direction. The pixel group may include four unit pixels arranged in a 2×2 matrix. In the following description, the first direction D1 and the second direction D2 may indicate directions crossing each other. For example, in the XY coordinate system, the first direction D1 may be set as the X-axis direction, and the second direction D2 may be set as the Y-axis direction.

[0036] Figure 2 is a perspective view illustrating a part of a pixel array in an image sensing device according to some embodiments of the disclosed technology. Figure 3 is a plan view illustrating a phase difference detection pixel group in an image sensing device according to some embodiments of the disclosed technology. As a reference, for a clearer description of the shape of the light-shielding pattern, the illustration of the grid pattern is omitted from Figure 3 therein.

[0037] As Figure 2 andFigure 3 As shown, the pixel array 110 (see Figure 1 ) may include a plurality of unit pixels arranged in a matrix. The plurality of unit pixels may include a plurality of phase difference detection pixels PDPX and a plurality of image detection pixels IPX. That is, the plurality of phase difference detection pixels PDPX and the plurality of image detection pixels IPX may be arranged in a matrix. In some implementations, four phase difference detection pixels PDPX1 to PDPX4 may form a phase difference detection pixel group 410, and the pixel array 110 may include one or more phase difference detection pixel groups 410. Similarly, four image detection pixels IPX1 to IPX4 may form an image detection pixel group, and the pixel array 110 may include a plurality of image detection pixel groups.

[0038] The phase difference detection pixel group 410 may include a photoelectric conversion element PD, a filter layer 440 including different color filters, a microlens layer 450 including one or more microlenses, a light shielding pattern 430, and a grid pattern 420. The photoelectric conversion element PD may be formed in the substrate 400 at positions corresponding to the first phase difference detection pixel PDPX1 to the fourth phase difference detection pixel PDPX4, respectively. The filter layer 440 may be formed on the substrate 400, and one or more microlenses 450 may be formed on or above the filter layer 440. The light shielding pattern 430 may limit the light receiving regions LR1 to LR4 of the first phase difference detection pixel PDPX1 to the fourth phase difference detection pixel PDPX4, and the grid pattern 420 may start from the light shielding pattern 430 and extend along the boundaries between the respective phase difference detection pixels PDPX1 to PDPX4.

[0039] The components other than the light shielding pattern 430 in each image detection pixel group may be formed in the same manner as the phase difference detection pixel group 410.

[0040] The photoelectric conversion element PD may be used to generate photo charges corresponding to incident light that has passed through the microlens layer 450 and the filter layer 440. Examples of the photoelectric conversion element PD may include a photodiode, a phototransistor, a photogate, a PPD, or a combination thereof. For example, the photoelectric conversion element PD may be a photodiode. The photodiode may include an N-type impurity region and a P-type impurity region stacked in the vertical direction.

[0041] The filter layer 440 may include different color filters, where the color filters are placed above the pixels to filter the light received by the pixels. Such a filter layer 440 may be configured to capture color information in an image, and the spatial arrangement of different color filters is designed to filter incident light using different color filters in adjacent pixels to capture the color information of the scene or object to be imaged. One suitable color filter arrangement is a Bayer color filter array of different color filters, where 50% of the total color filters are green (G), 25% of the total color filters are blue (B), and 25% of the total color filters are red (R). One of the different implementations of the Bayer color filter array for placing adjacent color filters of the same color in a row or column is the Quad-Bayer pixel structure, where adjacent 2×2 pixels of a 4-pixel block have the same color as the basic building block, while the Bayer color arrangement is achieved by making 50% of the total 4-pixel filter block green (G), 25% of the total 4-pixel filter block blue (B), and 25% of the total 4-pixel filter block red (R). Figure 2 An example of Figure 2 shows an example of such a Quad-Bayer pixel structure in a 4×4 4-pixel block pattern including a 4-pixel block of blue filter, a 4-pixel block of red filter, and two 4-pixel blocks of green filter.

[0042] The first phase difference detection pixel PDPX1 to the fourth phase difference detection pixel PDPX4 may generate pixel signals in response to incident light rays in the same wavelength band. That is, the first phase difference detection pixel PDPX1 to the fourth phase difference detection pixel PDPX4 may each include a color filter having the same color. In one example, each of the first phase difference detection pixel PDPX1 to the fourth phase difference detection pixel PDPX4 includes a green color filter. However, the disclosed technology is not limited thereto. As another example, each of the first phase difference detection pixel PDPX1 to the fourth phase difference detection pixel PDPX4 may include any one selected from the group consisting of a red color filter, a blue color filter, an IR filter, and a white filter. The white filter may represent a filter that allows incident light to pass through without filtering a specific wavelength band.

[0043] In some implementations, the first phase difference detection pixel PDPX1 to the fourth phase difference detection pixel PDPX4 may share a microlens 450. As another example, the phase difference detection pixel group 410 may include two or more microlenses 450. In some implementations, the phase difference detection pixel group 410 may include two microlenses 450 each having an elliptical planar shape, and the first phase difference detection pixel PDPX1 and the second phase difference detection pixel PDPX2 or the third phase difference detection pixel PDPX3 adjacent to the first phase difference detection pixel PDPX1 may share a microlens 450, and the other phase difference detection pixels PDPX may share another microlens 450. In other implementations, the phase difference detection pixel group 410 may include four microlenses 450 each having a circular or rectangular planar shape, and the four microlenses 450 may be arranged to correspond to the first phase difference detection pixel PDPX1 to the fourth phase difference detection pixel PDPX4 respectively.

[0044] In some implementations, the light-shielding pattern 430 and the grid pattern 420 may be located between the substrate 400 and the filter layer 440. As another example, the light-shielding pattern 430 and the grid pattern 420 may be located between the filter layer 440 and the microlens layer 450. The light-shielding pattern 430 and the grid pattern 420 may include a material capable of blocking, absorbing, or reflecting incident light, such as a metal material. The grid pattern 420 may be used to prevent optical crosstalk between adjacent pixels.

[0045] The light-shielding pattern 430 may be used to define the light reception regions LR1 to LR4 of the first phase difference detection pixel PDPX1 to the fourth phase difference detection pixel PDPX4, and may be located at the center of the phase difference detection pixel group 410. Therefore, the phase difference detection pixel group 410 may include one light-shielding pattern 430, and the light-shielding pattern 430 may overlap with all of the first phase difference detection pixel PDPX1 to the fourth phase difference detection pixel PDPX4. In other words, the light-shielding pattern 430 may be formed as a single pattern overlapping a part of the photoelectric conversion elements PD of two or more phase difference detection pixels PDPX. Here, the overlapping areas between the light-shielding pattern 430 and the corresponding first phase difference detection pixel PDPX1 to the fourth phase difference detection pixel PDPX4 may be equal to each other.

[0046] To enable the phase-difference detection pixel group 410 to perform the PDAF function in the vertical, horizontal, and diagonal directions, the light-shielding pattern 430 shields two or more phase-difference detection pixels PDPX, and the light-receiving regions LR surrounding the light-shielding pattern 430 allow a limited amount of light to pass through and enter two or more phase-difference detection pixels PDPX. Each light-receiving region LR may include an L-shaped structure. In some implementations, each light-receiving region may include a plurality of L-shaped openings. In one example, each light-receiving region LR may include a first region and a second region. The first region may extend in a first direction D1, and the second region may extend in a second direction D2. In some implementations, the width of the first region in the second direction may be equal to the width of the second region in the first direction. In some implementations, the light-shielding pattern 430 may have a rectangular planar shape surrounded by four light-receiving regions LR each having an L-shaped structure.

[0047] In some implementations, the first to fourth phase-difference detection pixels PDPX1 to PDPX4 of the phase-difference detection pixel group 410 may respectively include first to fourth light-receiving regions LR1 to LR4 each having an L-shaped structure, and the light-shielding pattern 430 is located at the center of the phase-difference detection pixel group 410. The light-shielding pattern 430 covers the center of the phase-difference detection pixel group 410 of the four phase-difference detection pixels, leaving the edge regions of the phase-difference detection pixel group 410 as the light-receiving regions LR1 to LR4. In some implementations, each of the light-receiving regions LR1 to LR4 has an L shape, and the light-receiving regions LR1 to LR4 are arranged such that the light-shielding pattern 430 is surrounded by the light-receiving regions LR1 to LR4. In one example, the first light-receiving region LR1 and the second light-receiving region LR2 may be symmetric about the second direction D2, and the third light-receiving region LR3 and the fourth light-receiving region LR4 may be symmetric with each other in the second direction D2. The first light-receiving region LR1 and the third light-receiving region LR3 may be symmetric about the first direction D1, and the second light-receiving region LR2 and the fourth light-receiving region LR4 may be symmetric about the first direction D1. The first to fourth light-receiving regions LR1 to LR4 may have substantially the same area. In some implementations, the first to fourth light-receiving regions LR1 to LR4 may be symmetric about the center of the phase-difference detection pixel group 410 such that each of the first to fourth light-receiving regions LR1 to LR4 has substantially the same light-receiving area.

[0048] To detect the phase difference in the horizontal direction or the first direction D1, the phase difference detection pixel group 410 can generate data on the phase difference in the first direction D1 by comparing the sum of the pixel signals generated by the first phase difference detection pixel PDPX1 and the third phase difference detection pixel PDPX3 with the sum of the pixel signals generated by the second phase difference detection pixel PDPX2 and the fourth phase difference detection pixel PDX4. To detect the phase difference in the vertical direction or the second direction D2, the phase difference detection pixel group 410 can generate data on the phase difference in the second direction D2 by comparing the sum of the pixel signals generated by the first phase difference detection pixel PDPX1 and the second phase difference detection pixel PDPX2 with the sum of the pixel signals generated by the third phase difference detection pixel PDPX3 and the fourth phase difference detection pixel PDX4. In addition, to detect the phase difference in the diagonal direction, the phase difference detection pixel group 410 can generate data on the phase difference in the diagonal direction by comparing the pixel signal generated by the first phase difference detection pixel PDPX1 with the pixel signal generated by the fourth phase difference detection pixel PDPX4, or by comparing the pixel signal generated by the second phase difference detection pixel PDPX2 with the pixel signal generated by the third phase difference detection pixel PDPX3.

[0049] The disclosed technology can be implemented in some embodiments to provide a phase difference detection pixel group 410, which can also generate HDR image data by performing operations on the pixel signals generated by the first phase difference detection pixel PDPX1 to the fourth phase difference detection pixel PDPX4.

[0050] As described above, the first phase difference detection pixel PDPX1 to the fourth phase difference detection pixel PDPX4 of the phase difference detection pixel group 410 according to some embodiments of the disclosed technology can respectively include the first light receiving region LR1 to the fourth light receiving region LR4, such that the light shielding pattern 430 is surrounded by the first light receiving region LR1 to the fourth light receiving region LR4. The pixel signals generated by a single phase difference detection pixel group 410 can be processed to obtain an HDR image. Therefore, the phase difference detection pixel group 410 implemented according to some embodiments of the disclosed technology can simultaneously perform the single-trigger HDR imaging function and the PDAF function in the horizontal direction, the vertical direction, and the diagonal direction.

[0051] Figures 4A to 4D is a plan view illustrating a modified example of the phase difference detection pixel group 410 in an image sensing device according to some embodiments of the disclosed technology. It will be described below with reference to Figures 4A to 4DThe described phase difference detection pixel groups 411 to 414 can simultaneously perform the PDAF function and the single-shot HDR imaging function, and generate a more enhanced HDR image. To more clearly illustrate the shape of the light-shielding pattern, the grid pattern is omitted from Figures 4A to 4D as shown.

[0052] As Figures 4A to 4D shown, each of the phase difference detection pixel groups 411 to 414 based on other example implementations may include a first light-receiving region LR1 to a fourth light-receiving region LR4 having an L-shaped structure with various widths. Since the phase difference detection pixels PDPX in one phase difference detection pixel group have different light-receiving areas, a more enhanced HDR image can be generated.

[0053] As Figure 4A shown, the first light-receiving region LR1 of the phase difference detection pixel group 411 may be symmetric with respect to the light-shielding pattern 431 to any one of the second light-receiving region LR2 to the fourth light-receiving region LR4. In addition, the first light-receiving region LR1 may have a light-receiving area substantially the same as that of any one of the second light-receiving region LR2 to the fourth light-receiving region LR4 that is symmetric with the first light-receiving region LR1.

[0054] In some implementations, in the phase difference detection pixel group 411, the area of the first light-receiving region LR1 and the area of the second light-receiving region LR2 may be equal to each other, and the area of the third light-receiving region LR3 and the area of the fourth light-receiving region LR4 may be equal to each other. Here, the area of the first light-receiving region LR1 may be greater than the area of the third light-receiving region LR3. The first light-receiving region LR1 and the second light-receiving region LR2 may be symmetric about the second direction D2, and the third light-receiving region LR3 and the fourth light-receiving region LR4 may be symmetric about the second direction D2.

[0055] As Figure 4B shown, the first light-receiving region LR1 of the phase difference detection pixel group 412 may be symmetric with respect to the light-shielding pattern 432 to any one of the second light-receiving region LR2 to the fourth light-receiving region LR4. In addition, the first light-receiving region LR1 may have a light-receiving area substantially the same as that of any one of the second light-receiving region LR2 to the fourth light-receiving region LR4 that is symmetric with the first light-receiving region LR1.

[0056] In some implementations, in the phase difference detection pixel group 412, the area of the first light receiving region LR1 and the area of the third light receiving region LR3 can be equal to each other, and the area of the second light receiving region LR2 and the area of the fourth light receiving region LR4 can be equal to each other. Here, the area of the first light receiving region LR1 can be greater than the area of the second light receiving region LR2. The first light receiving region LR1 and the third light receiving region LR3 can be symmetric about the first direction D1, and the second light receiving region LR2 and the fourth light receiving region LR4 can be symmetric about the first direction D1.

[0057] As Figure 4C shown, the first light receiving region LR1 of the phase difference detection pixel group 413 can be symmetric with respect to the light shielding pattern 433 to any one of the light receiving regions of the second light receiving region LR2 to the fourth light receiving region LR4. In addition, the first light receiving region LR1 can have a light receiving area substantially the same as that of any one of the light receiving regions of the second light receiving region LR2 to the fourth light receiving region LR4 that is symmetric with the first light receiving region LR1.

[0058] In some implementations, in the phase difference detection pixel group 413, the area of the first light receiving region LR1 and the area of the fourth light receiving region LR4 can be equal to each other, and the area of the second light receiving region LR2 and the area of the third light receiving region LR3 can be equal to each other. Here, the area of the second light receiving region LR2 can be greater than the area of the first light receiving region LR1. The first light receiving region LR1 and the fourth light receiving region LR4 facing each other in the first diagonal direction can be symmetric about the center of the phase difference detection pixel group 413, while the second light receiving region LR2 and the third light receiving region LR3 facing each other in the second diagonal direction intersecting the first diagonal direction can be symmetric about the center of the phase difference detection pixel group 413.

[0059] As Figure 4D shown, the first light receiving region LR1 to the fourth light receiving region LR4 of the phase difference detection pixel group 414 can have different widths and areas while surrounding the light shielding pattern 434.

[0060] In some implementations, in the phase difference detection pixel group 414, the first light receiving region LR1 can have the smallest area, while the fourth light receiving region LR4 can have the largest area. Here, the area of the second light receiving region LR2 can be greater than the area of the first light receiving region LR1, and the area of the third light receiving region LR3 can be greater than the area of the second light receiving region LR2.

[0061] As described above, each of the first to fourth phase difference detection pixels PDPX1 to PDPX4 in the phase difference detection pixel groups 411 to 414 based on the modification example may include first to fourth light receiving regions LR1 to LR4 each having an L-shaped structure, and the light shielding patterns 431 to 434 are located at the centers of the corresponding phase difference detection pixel groups. Pixel signals generated by a single phase difference detection pixel group 411, 412, 413, or 414 can be processed to obtain an HDR image. Therefore, the phase difference detection pixel groups 411, 412, 413, or 414 implemented based on some embodiments of the disclosed technology can simultaneously perform the PDAF function in the horizontal, vertical, and diagonal directions and the single-shot HDR imaging function. In addition, the first to fourth light receiving regions LR1 to LR4 can be formed to have different light receiving areas, thereby obtaining a more enhanced HDR image.

[0062] In some embodiments of the disclosed technology, each of the phase difference detection pixel groups 410 to 414 includes four unit pixels arranged in a 2×2 matrix. In other embodiments of the disclosed technology, the pixel array 110 (see Figure 1 ) may include sub-pixel arrays each having a plurality of unit pixels arranged in a 3×3 or 4×4 matrix and configured to generate pixel signals in response to incident light in the same wavelength band, and the phase difference detection pixel groups 410 to 414 based on some embodiments of the disclosure may be arranged in each sub-pixel array. Here, the phase difference detection pixel groups 410 to 414 in each sub-pixel array may be arranged at the same position or different positions.

[0063] As will be discussed with reference to Figure 5 , a pixel group including nine unit pixels arranged in a 3×3 matrix can simultaneously perform the single-shot HDR imaging function and the PDAF function in the vertical, horizontal, and diagonal directions. To more clearly illustrate the shape of the light shielding pattern, the grid pattern is omitted from Figure 5 .

[0064] Figure 5 is a plan view illustrating an example of a phase difference detection pixel group in an image sensing device based on an embodiment of the disclosed technology.

[0065] In some implementations, the phase difference detection pixel group 415 may include photoelectric conversion elements PD1 to PD9, a filter (not shown), one or more microlenses (not shown), a light-shielding pattern 435, and a grid pattern (not shown). The photoelectric conversion elements PD1 to PD9 may be formed in a substrate (not shown) at positions corresponding to the first phase difference detection pixel PDPX1 to the ninth phase difference detection pixel PDPX9, respectively. The filter may be formed on the substrate, and one or more microlenses may be formed on the filter. The light-shielding pattern 435 may limit the light reception region LR of the first phase difference detection pixel PDPX1 to the ninth phase difference detection pixel PDPX9, and the grid pattern may start from the light-shielding pattern 435 and extend along the boundaries between the corresponding phase difference detection pixels PDPX.

[0066] To enable the phase difference detection pixel group 415 to perform the PDAF function in the horizontal direction, vertical direction, and diagonal direction, the light-shielding pattern 435 may provide the light reception region LR, and the light-shielding pattern 435 is configured to block at least a portion of two or more phase difference detection pixels PDPX. The light reception region LR may be configured to allow a limited amount of light to pass through and enter the phase difference detection pixel group 415. In some implementations, the light reception region LR may include one or more L-shaped structures and / or one or more I-shaped or linear structures.

[0067] In some implementations, the phase difference detection pixel group 415 may include a first phase difference detection pixel PDPX1, a third phase difference detection pixel PDPX3, a seventh phase difference detection pixel PDPX7, and a ninth phase difference detection pixel PDPX9. The first phase difference detection pixel PDPX1, the third phase difference detection pixel PDPX3, the seventh phase difference detection pixel PDPX7, and the ninth phase difference detection pixel PDPX9 are located at respective corners of the phase difference detection pixel group 415 due to the light shielding pattern 435 and respectively include first light receiving regions LR1, third light receiving regions LR3, seventh light receiving regions LR7, and ninth light receiving regions LR9 each having an L-shaped structure. In addition, the first light receiving region LR1 and the third light receiving region LR3 may be symmetric about the second direction D2, and the seventh light receiving region LR7 and the ninth light receiving region LR9 may be symmetric about the second direction D2. In addition, the first light receiving region LR1 and the seventh light receiving region LR7 may be symmetric about the first direction D1, and the third light receiving region LR3 and the ninth light receiving region LR9 may be symmetric about the first direction D1. The first light receiving region LR1, the third light receiving region LR3, the seventh light receiving region LR7, and the ninth light receiving region LR9 may have substantially the same area. In other words, the first light receiving region LR1, the third light receiving region LR3, the seventh light receiving region LR7, and the ninth light receiving region LR9 may be symmetric with each other and thus have substantially the same light receiving area.

[0068] The first phase difference detection pixel PDPX1, the third phase difference detection pixel PDPX3, the seventh phase difference detection pixel PDPX7, and the ninth phase difference detection pixel PDPX9 may generate pixel signals in response to incident light rays in the same wavelength band. For example, the first phase difference detection pixel PDPX1, the third phase difference detection pixel PDPX3, the seventh phase difference detection pixel PDPX7, and the ninth phase difference detection pixel PDPX9 may include the same color filter, for example, a green color filter.

[0069] In addition, the phase difference detection pixel group 415 may include a second phase difference detection pixel PDPX2, a fourth phase difference detection pixel PDPX4, a sixth phase difference detection pixel PDPX6, and an eighth phase difference detection pixel PDPX8. The second phase difference detection pixel PDPX2, the fourth phase difference detection pixel PDPX4, the sixth phase difference detection pixel PDPX6, and the eighth phase difference detection pixel PDPX8 are located between respective corners of the phase difference detection pixel group 415, and the light shielding pattern 435 is located at the center of the phase difference detection pixel group 415. The second phase difference detection pixel PDPX2, the fourth phase difference detection pixel PDPX4, the sixth phase difference detection pixel PDPX6, and the eighth phase difference detection pixel PDPX8 respectively include second light receiving regions LR2, fourth light receiving regions LR4, sixth light receiving regions LR6, and eighth light receiving regions LR8 each having an I-shaped structure or a linear structure. The fourth light receiving region LR4 and the sixth light receiving region LR6 may be symmetric about the second direction D2, and the second light receiving region LR2 and the eighth light receiving region LR8 may be symmetric about the first direction D1. The second light receiving region LR2, the fourth light receiving region LR4, the sixth light receiving region LR6, and the eighth light receiving region may have substantially the same area.

[0070] The second phase difference detection pixel PDPX2, the fourth phase difference detection pixel PDPX4, the sixth phase difference detection pixel PDPX6, and the eighth phase difference detection pixel PDPX8 may generate pixel signals in response to incident light rays in the same wavelength band. For example, the second phase difference detection pixel PDPX2, the fourth phase difference detection pixel PDPX4, the sixth phase difference detection pixel PDPX6, and the eighth phase difference detection pixel PDPX8 may include the same color filter, for example, a green color filter.

[0071] The second phase difference detection pixel PDPX2 and the eighth phase difference detection pixel PDPX8 facing each other in the second direction D2 may generate pixel signals in response to incident light rays in the first wavelength band, and the fourth phase difference detection pixel PDPX4 and the sixth phase difference detection pixel PDPX6 facing each other in the first direction D1 may generate pixel signals in response to incident light rays in the second wavelength band. For example, the second phase difference detection pixel PDPX2 and the eighth phase difference detection pixel PDPX8 may include the same color filter, for example, a red color filter. On the other hand, the fourth phase difference detection pixel PDPX4 and the sixth phase difference detection pixel PDPX6 may include the same color filter, for example, a blue color filter.

[0072] The light-shielding pattern 435 may have an annular planar shape as a single pattern, and this single pattern overlaps with a part of the photoelectric conversion elements PD of the first to fourth phase difference detection pixels PDPX1 to PDPX4 and the sixth to ninth phase difference detection pixels PDPX6 to PDPX9 along the edge of the fifth phase difference detection pixel PDPX5 located at the center of the phase difference detection pixel group 415. The fifth light reception region LR5 of the fifth phase difference detection pixel PDPX5 located at the center of the phase difference detection pixel group 415 may have the same area as the light reception region of the image detection pixel IPX (see Figure 1 ).

[0073] Although various embodiments have been described above, the described embodiments are merely examples. Variations and enhancements can be made to the disclosed embodiments and other embodiments based on what is described and / or illustrated in this patent document.

[0074] Cross-reference to related applications

[0075] This patent document claims the priority and benefits of Korean Patent Application No. 10-2021-0008717, filed on January 21, 2021, the entire content of which is incorporated herein by reference.

Claims

1. An image sensing device, the image sensing device comprising: A substrate; A pixel array, the pixel array including one or more groups of phase difference detection pixels supported by the substrate and responsive to incident light, each group of phase difference detection pixels including two or more phase difference detection pixels for detecting a phase difference of the incident light, wherein, the group of phase difference detection pixels includes a light shielding pattern, the light shielding pattern providing a light receiving area to each of the two or more phase difference detection pixels, each light receiving area being formed along two consecutive sides of each of the two or more phase difference detection pixels, and wherein, the light receiving area of each of the phase difference detection pixels is arranged along an edge of the group of phase difference detection pixels, the light shielding pattern being located at a center of the group of phase difference detection pixels and spaced apart from the edge of the group of phase difference detection pixels.

2. The image sensing device according to claim 1, wherein, Each of the phase difference detection pixels in the group of phase difference detection pixels generates a pixel signal in response to incident light in the same wavelength band.

3. The image sensing device according to claim 1, wherein, The phase difference detection pixels including the light receiving areas each having an L shape are located at corners of the group of phase difference detection pixels.

4. The image sensing device according to claim 1, wherein, The light shielding pattern is formed as a single pattern that overlaps a part of the photoelectric conversion elements of two or more of the phase difference detection pixels.

5. The image sensing device according to claim 1, wherein The light receiving area includes a first linear area extending in a first direction and a second linear area extending in a second direction intersecting the first direction, and wherein, a width of the first linear area in the second direction is equal to a width of the second linear area in the first direction.

6. The image sensing device according to claim 1, wherein, The group of phase difference detection pixels includes: One or more photoelectric conversion elements formed in the substrate; One or more filters formed above the substrate; and One or more microlenses formed on the one or more filters.

7. The image sensing device according to claim 6, wherein, The light shielding pattern is located between the substrate and the one or more filters.

8. The image sensing device according to claim 6, wherein, The light shielding pattern is located between the one or more filters and the one or more microlenses.

9. The image sensing device according to claim 1, wherein, The group of phase difference detection pixels further includes a grid pattern starting from the light shielding pattern and extending along boundaries between the phase difference detection pixels.

10. An image sensing device, the image sensing device comprising: A substrate; A pixel array, the pixel array including one or more groups of phase difference detection pixels supported by the substrate and responsive to incident light, each group of phase difference detection pixels including a first phase difference detection pixel, a second phase difference detection pixel, a third phase difference detection pixel, and a fourth phase difference detection pixel arranged in a 2×2 matrix, Wherein, the phase difference detection pixel group includes a light shielding pattern and first to fourth phase difference detection pixels, and wherein, the light shielding pattern is disposed at the center of the phase difference detection pixel group to shield at least a part of the phase difference detection pixel group, and respectively provides a first light receiving region, a second light receiving region, a third light receiving region, and a fourth light receiving region each having an L shape to the first to fourth phase difference detection pixels, and Wherein, the first to fourth light receiving regions are arranged along the edge of the phase difference detection pixel group, and the light shielding pattern is located at the center of the phase difference detection pixel group and is spaced apart from the edge of the phase difference detection pixel group.

11. The image sensing device according to claim 10, wherein, The first to fourth phase difference detection pixels generate pixel signals in response to incident light rays in the same wavelength band.

12. The image sensing device according to claim 10, wherein, The first to fourth light receiving regions are symmetric with each other and have the same light receiving area.

13. The image sensing device according to claim 10, wherein, The first light receiving region is symmetric with any one of the second to fourth light receiving regions and has the same light receiving area as any one of the second to fourth light receiving regions that is symmetric with the first light receiving region.

14. The image sensing device according to claim 10, wherein, The first to fourth light receiving regions have different light receiving areas.

15. The image sensing device according to claim 10, wherein, The light shielding pattern is formed as a single pattern that overlaps at least a part of the photoelectric conversion elements of the first to fourth phase difference detection pixels.

16. The image sensing device according to claim 10, wherein, Each of the first to fourth light receiving regions includes a first linear region extending in a first direction and a second linear region extending in a second direction intersecting the first direction, and wherein, the width of the first linear region in the second direction is equal to the width of the second linear region in the first direction.

17. The image sensing device according to claim 10, wherein, The phase difference detection pixel group includes: One or more photoelectric conversion elements formed in the substrate; One or more filters formed above the substrate; and One or more microlenses formed on the one or more filters.

18. The image sensing device according to claim 17, wherein, The light shielding pattern is located between the substrate and the one or more filters.

19. The image sensing device according to claim 17, wherein, The light shielding pattern is located between the one or more filters and the one or more microlenses.

20. The image sensing device according to claim 10, wherein, The phase difference detection pixel group further includes a grid pattern that starts from the light shielding pattern and extends along the boundaries between the phase difference detection pixels.

21. An image sensing device, the image sensing device includes: A substrate; A pixel array having one or more groups of phase difference detection pixels supported by the substrate and responsive to incident light, each group of phase difference detection pixels including a first phase difference detection pixel, a second phase difference detection pixel, a third phase difference detection pixel, a fourth phase difference detection pixel, a fifth phase difference detection pixel, a sixth phase difference detection pixel, a seventh phase difference detection pixel, an eighth phase difference detection pixel, and a ninth phase difference detection pixel arranged in a 3×3 matrix and each including a photoelectric conversion element. Wherein, the group of phase difference detection pixels includes a light-shielding pattern that provides first light-receiving regions, third light-receiving regions, seventh light-receiving regions, and ninth light-receiving regions each having an L shape for the first phase difference detection pixel, the third phase difference detection pixel, the seventh phase difference detection pixel, and the ninth phase difference detection pixel located at the four corners of the group of phase difference detection pixels, respectively, and Wherein, the light-shielding pattern is formed as a single pattern that overlaps a part of the photoelectric conversion elements of the first phase difference detection pixel to the fourth phase difference detection pixel and the sixth phase difference detection pixel to the ninth phase difference detection pixel along the edge of the fifth phase difference detection pixel located at the center of the group of phase difference detection pixels, and is spaced apart from the edge of the group of phase difference detection pixels.

22. The image sensing device according to claim 21, wherein, The first phase difference detection pixel, the third phase difference detection pixel, the seventh phase difference detection pixel, and the ninth phase difference detection pixel generate pixel signals in response to incident light in the same wavelength band.

23. The image sensing device according to claim 21, wherein, The first light-receiving region, the third light-receiving region, the seventh light-receiving region, and the ninth light-receiving region are symmetric with each other and have the same light-receiving area.

24. The image sensing device according to claim 21, wherein, The light-shielding pattern includes second light-receiving regions, fourth light-receiving regions, sixth light-receiving regions, and eighth light-receiving regions, and each of the second light-receiving regions, fourth light-receiving regions, sixth light-receiving regions, and eighth light-receiving regions has a linear region corresponding to the second phase difference detection pixel, the fourth phase difference detection pixel, the sixth phase difference detection pixel, and the eighth phase difference detection pixel, respectively. The second phase difference detection pixel, the fourth phase difference detection pixel, the sixth phase difference detection pixel, and the eighth phase difference detection pixel are located between the first phase difference detection pixel and the third phase difference detection pixel, between the first phase difference detection pixel and the seventh phase difference detection pixel, between the third phase difference detection pixel and the ninth phase difference detection pixel, and between the ninth phase difference detection pixel and the seventh phase difference detection pixel in the group of phase difference detection pixels, respectively.

25. The image sensing device according to claim 24, wherein, The second light-receiving region and the eighth light-receiving region facing each other in one direction are symmetric with each other and have the same light-receiving area, and the fourth light-receiving region and the sixth light-receiving region facing each other in another direction are symmetric with each other and have the same light-receiving area.

26. The image sensing device according to claim 24, wherein, The second phase difference detection pixel, the fourth phase difference detection pixel, the sixth phase difference detection pixel, and the eighth phase difference detection pixel generate pixel signals in response to incident light in the same wavelength band.

27. The image sensing device according to claim 24, wherein, The second phase difference detection pixel and the eighth phase difference detection pixel facing each other in one direction generate pixel signals in response to incident light in the first wavelength band, and the fourth phase difference detection pixel and the sixth phase difference detection pixel facing each other in the other direction generate pixel signals in response to incident light in the second wavelength band.

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