Phase detection autofocus pixel element

Abstract

A phase detection autofocus pixel element (1), the phase detection autofocus pixel element comprising: a photodiode (2); a plurality of microlenses (3) for concentrating light incident on each of the microlenses (3) onto the photodiode (2); and a light shield (4) for each microlens (3), associated with each microlens (3), for blocking a portion of the light transmitted by the microlens (3) towards the photodiode (2), in which the light shield (4) is offset in the same offset direction (X) with respect to the optical axis (31) of the microlens (3) to which the light shield (4) is associated.

Description

Technical Field

[0001] The invention relates to the field of phase detection auto-focus pixel elements. Background Art

[0002] Phase detection autofocus (PDAF) pixel elements are commonly used in CMOS image sensors (CIS). PDAF pixel elements can directly measure the amount of (out-of-)focus and, if out-of-focus, the direction of the out-of-focus (front focus, back focus). As a result, the camera's lens can be quickly adjusted to bring the image into focus. PDAF pixel elements can achieve faster focusing than, for example, applying contrast autofocus.

[0003] refer to Figure 1A , which corresponds to FIG. 17 of US6829008B1, which shows an image sensor 61 of a camera including a plurality of PDAF pixel elements 9. In the prior art, each PDAF pixel element 9 comprises a single microlens 93. For illustrative purposes, in this example, each PDAF pixel element 9 comprises a first photodiode S1 and a second photodiode S2, which are offset in opposite directions, i.e., in the -X and X directions, respectively, relative to the optical axis 95 of the microlens 93 of the PDAF pixel element 9. The camera also comprises a camera lens 5.

[0004] The following describes how to use the PDAF pixel element 9 to determine whether the camera is focused. It is assumed here that the function of the PDAF pixel element 9 is idealized, ignoring the limited focusing ability of the microlens, which will be described later.

[0005] It can be assumed that the light from each specific point on the object (the object is not shown) collected by the camera lens 5 is divided into a first light beam L1 and a second light beam L2. Figure 1A , only the light collected by the camera lens 5 from a single specific point on the object is shown. The first light beam L1 propagates through the first half of the camera lens 5, then passes through the microlens 93 of one of the PDAF pixel elements 9, and is incident on the first photodiode S1 of the PDAF pixel element 9. The second light beam L2 propagates through the second half of the camera lens 5, then passes through the microlens 93 of one of the PDAF pixel elements 9, and is incident on the second photodiode S2 of the PDAF pixel element 9.

[0006] When the camera focuses on an object, such as Figure 1AIn the case of FIG. 5 , the camera lens 5 focuses the light from each point on the object onto the microlens 93 of the image sensor 61, thereby generating an image of the object on the plane of the microlens 93. In this way, when the camera is focused, the two light beams L1 and L2 from each specific point on the object are focused on a single point on the microlens 93 of a single PDAF pixel element 9. Therefore, when focusing, the first photodiode S1 that detects the first light beam L1 from the specific point on the object and the second photodiode S2 that detects the second light beam L2 from the specific point on the object are located in the same PDAF pixel element 9. Therefore, when focusing, the first image of the object formed by the L1 light beam detected by the first photodiode S1 of the image sensor 61 and the second image of the object formed by the L2 light beam detected by the second photodiode S2 of the image sensor 61 overlap on the same pixel element.

[0007] Figure 2 FIG. 17 corresponding to US6829008B1 shows a situation where the camera is out of focus, more specifically, in the front focus situation. Figure 2 As shown, when out of focus, the first light beam L1 and the second light beam L2 from each specific point on the object intersect each other at a position far away from the plane of the microlens 93. Therefore, when out of focus, for the light beam L1 and the light beam L2 from each specific point on the object, the first light beam L1 and the second light beam L2 are incident on different microlenses 93, so that the first photodiode S1 detecting the first light beam L1 and the second photodiode S2 detecting the second light beam L2 are located in different PDAF pixel elements 9. Therefore, as can be seen in Figure 3 As observed in FIG. 19 corresponding to US6829008B1, when out of focus, the first image of the object detected by the first photodiode S1 of the image sensor 61 ("S1 image") deviates relative to the second image of the object detected by the second photodiode S2 of the image sensor 61 ("S2 image") . As further explained in US6829008B1, the magnitude of this deviation can be directly related to the distance between the point where the first light beam L1 and the second light beam L2 from a particular point on the object intersect and the plane of the microlens 93, thereby directly determining the distance that the camera lens 5 must move along the optical axis 50 of the camera lens 5 to bring the camera into focus with the object.

[0008] refer to Figure 1B. Although each PDAF pixel element includes two photodiodes (i.e., a first photodiode S1 and a second photodiode S2) for illustrative purposes above, in reality, a single pixel element 91, 910 typically only includes a single photodiode 92, 920. Therefore, in reality, a single PDAF pixel element 91, 910 cannot detect the first light beam L1 and the second light beam L2 independently of each other. The art solves this problem by using pairs of PDAF pixel elements 91 and 910. Each pair includes a first PDAF pixel element 91 for detecting the first light beam L1, the first PDAF pixel element 91 including a microlens 93 and a light shielding member 94, the light shielding member 94 is offset in a first offset direction X relative to an optical axis 95 of the microlens 93, and covers half of the photodiode 92 of the first PDAF pixel element 91 on one side of the optical axis 95 in the first offset direction X, thereby blocking the second light beam L2. Each pair further includes a second PDAF pixel element 910 for detecting the second light beam L2, the second PDAF pixel element 910 including a microlens 930 and a light shield 940, the light shield 940 being offset along a second offset direction -X opposite to the first offset direction X relative to the optical axis 950 of the microlens 930, and covering half of the photodiode 920 of the second PDAF pixel element 910 on one side of the optical axis 950 in the second offset direction -X, thereby blocking the first light beam L1. Therefore, the first PDAF pixel element 91 of the image sensor 62 basically detects the light beam L2 emitted by the microlens 930. Figure 1A and Figure 2 The first photodiode S1 in the illustrative example corresponds to the first image measured (ie, Figure 3 The second PDAF pixel element 910 of the image sensor 62 basically detects the Figure 1A and Figure 2 The second photodiode S2 in the illustrative example corresponds to the measured second image (ie Figure 3 Of course, for each specific point on the object, only the first beam L1 or the second beam L2 is measured, and the resolution of the image will be slightly reduced.

[0009] refer to Figure 4A, shows a first PDAF pixel element 91 and a second PDAF pixel element 910, in which different light beams with the same specific incident angle α are incident (corresponding to the first light beam L1 from different adjacent positions on the object, propagating through the first half of the camera lens). The figure on the left represents the direction of the incident angle α of the light incident on the microlenses 93 and 930. Here, the incident angle α is located in a plane parallel to the optical axes 95 and 950 of the microlenses 93 and 930 and parallel to the X-axis (the light shielding members 94 and 940 deviate from the optical axes 95 and 950 of the respective PDAF pixel elements 91 and 910 along the X-axis), and relative to the normal incidence, the normal incidence is along the optical axes 95 and 950 of the microlenses 93 and 930. Here, the direction of the incident light having an X component pointing in the X direction has a negative incident angle α, and the direction of the incident light having an X component pointing in the -X direction has a positive incident angle α.

[0010] The ideal function of the above-mentioned PDAF pixel elements 91, 910, without intra-pixel element crosstalk, means that the first PDAF pixel element 91 has perfect selectivity for the first light beam L1, and the second PDAF pixel element has perfect selectivity for the second light beam L2. This can be achieved when the first PDAF pixel element 91 detects all light beams with a positive incident angle α (i.e., the first light beam L1) and its light shield 94 blocks all light with a negative incident angle α (i.e., the second light beam L2), and the second PDAF pixel element 910 detects all light beams with a negative incident angle α and its light shield 940 blocks all light with a positive incident angle α. This good selectivity can be achieved when each microlens 93, 930 clearly focuses the light from each incident angle α on the plane of the light shield 94, 940, as shown. Figure 4A As shown, the light with a negative incident angle α or a positive incident angle α collected by each microlens 93 , 930 is focused in a first direction X or a second direction −X relative to the optical axis 95 , 950 , respectively.

[0011] refer to Figure 4B , which shows the quantum efficiency (QE) of a conventional (non-PDAF) pixel element (denoted by 1100), a PDAF pixel element with an unoptimized structure (denoted by 1200), and a second PDAF pixel element with a well-optimized structure (denoted by 1300) as a function of the incident angle α.

[0012] For the well-optimized second PDAF pixel element (denoted by 1300), it can be observed that such good focus in the plane, and correspondingly such good selectivity, the second PDAF pixel element can sense light with negative incidence angles, but hardly detect any light with positive incidence angles. In practice, it is usually difficult to achieve such a sharp focus in the plane of the light shield, for example, because the microlens is not well optimized in structure. Therefore, as observed for the unoptimized PDAF pixel element (denoted by 1200), the second PDAF pixel element presents a limited focusing capability of the microlens, which means that, undesirably, the second PDAF pixel element does detect a considerable portion of the light with positive incidence angle (i.e., the first light beam L1), while a considerable portion of the light with negative incidence angle (i.e., the second light beam L2) is blocked by the light shield, thereby reducing its sensitivity and accuracy. Of course, this limited focusing capability is also correspondingly presented by the first PDAF pixel element. The more limited the focusing capability of the microlens of the PDAF pixel element, the more the shape of the curve is reminiscent of a conventional pixel element (indicated by 1100), which of course does not exhibit any selectivity for positive or negative angles of incidence. Due to the limited focusing capability of the microlens, the contrast between the first image and the second image detected by the first PDAF pixel element and the second PDAF pixel element, respectively, is reduced, resulting in reduced autofocus accuracy.

[0013] This limited focusing capability of the microlenses can be particularly problematic for image sensors that include large pixel elements, where the process capabilities are limited in terms of the shape, material, and height of the microlenses, as well as the height of the color filters and transparent planarization layers. For example, for large pixel elements, the height and radius of curvature of the microlenses can become so large that known manufacturing techniques cannot produce well-formed microlenses. As a result, for large pixel elements, it is particularly difficult for the microlenses to focus clearly on light from every angle of incidence on the plane of the light shield.

[0014] Therefore, there is still a need in the art for devices and methods that solve at least some of the above problems. Summary of the invention

[0015] One object of embodiments of the present invention is to provide a good phase detection autofocus pixel element. Another object of embodiments of the present invention is to provide a good image sensor comprising a pair of phase detection autofocus pixel elements. Yet another object of embodiments of the present invention is to provide a good camera comprising an image sensor.

[0016] The purpose of the embodiments of the present invention is to provide a good application of using phase detection auto-focus pixel elements to focus a camera lens.

[0017] The above objectives are achieved by the method and device according to the embodiments of the present invention.

[0018] An advantage of embodiments of the present invention is that the consequences of the limited focusing capability of the microlens can be limited. An advantage of embodiments of the present invention is that a good contrast can be obtained between a first image generated by a first phase detection autofocus pixel element and a second image generated by a second phase detection autofocus pixel element in a pair of phase detection autofocus pixel elements. Thus, a good quality of the phase detection autofocus function can be achieved.

[0019] In a first aspect, the present invention relates to a phase detection autofocus pixel element. The phase detection autofocus pixel element comprises a photodiode and a plurality of microlenses, the plurality of microlenses being used to concentrate light incident on each of the microlenses onto the photodiode. The phase detection autofocus pixel element also comprises a light shield for each microlens, the light shield being associated with each microlens, the light shield being used to block a portion of the light transmitted by the microlens toward the photodiode. The light shield is offset relative to the optical axis of the microlens associated with the light shield in the same offset direction. The light shield may have vertical edges and horizontal edges, but the light shield may also have inclined edges. An advantage of an embodiment of the present invention is that, in particular for large pixel elements, a plurality of lenses of smaller size may be used, such that the manufacturing technology is optimized, rather than using a single large microlens for each pixel element as in the prior art, because the height and radius of curvature of the microlens may become so large that known manufacturing technology cannot produce a well-shaped microlens.

[0020] The microlenses can be arranged in any manner, such as in an array. For example, the array may include N×M microlenses per pixel element, where N and M are integers that may be the same or different. In a preferred embodiment, a plurality of microlenses are arranged in a square array. In other words, the phase detection autofocus pixel element may include N×N microlenses, where N is an integer. Such a regular pattern can make manufacturing relatively easy. In an embodiment, the square microlens array includes rows and columns of microlenses, each row and column including at least two microlenses (ie, N is at least 2). For example, the square array may include 2 to 10 microlenses in rows and columns (ie, N is 2 to 10), or 2 to 4 microlenses in rows and columns (ie, N is 2 to 4). In an alternative embodiment, the microlenses are arranged in an array of N×M microlenses per pixel element, where N or M may be equal to one, as long as the other of M or N is equal to or greater than two.

[0021] In an embodiment, the shapes and sizes of the plurality of microlenses are substantially consistent. In an embodiment, each of the plurality of microlenses may have substantially the same aperture and substantially the same focal length. Typically, each microlens has a flat surface facing the photodiode and a convex surface facing away from the photodiode. For example, each microlens may be a spherical lens. In practice, the microlens may also have a rectangular parallelepiped shape with rounded corners and edges on the side of the microlens facing away from the photodiode. However, the present invention is not limited to microlenses of any shape. The shape typically depends on the manufacturing method.

[0022] In an embodiment, the shape and size of the light shielding member can be basically the same. In an embodiment, for different light shielding members and associated microlenses, the distance between each light shielding member and the microlens associated with the light shielding member is basically the same. Preferably, each light shielding member is offset substantially the same distance relative to the optical axis of the microlens associated with the light shielding member. The advantage of these embodiments is that the explanation of the detection signal detected by the photodiode may be very simple. However, in an alternative embodiment, the shape, size and / or offset of the light shielding member may be uneven on different pixel elements.

[0023] In a preferred embodiment, each light shield has a rectangular cross-section in the plane of the light shield. However, the present invention is not limited thereto, and the light shield may have any suitable shape. In a preferred embodiment, the light shield associated with the microlens blocks substantially all of the following light transmitted by the associated microlens: these lights would be collected by a photodiode located on one side of the optical axis of the associated microlens in the offset direction in the absence of the light shield. In addition, preferably, the light shield does not substantially block the following light: these lights would be collected by a photodiode located on the side opposite to the offset direction of the optical axis of the associated microlens in the absence of the light shield. The advantage of these embodiments is that good sensitivity and angular response of phase detection autofocus pixel elements can be achieved.

[0024] Each light shielding member can be formed of any material that can block light. For example, the material can effectively absorb visible light and / or effectively reflect visible light. In an embodiment, each light shielding member can be formed of a metal, such as tungsten, aluminum or copper. Metals are generally highly reflective and can therefore effectively block light.

[0025] In a second aspect, the present invention relates to an image sensor comprising a pair of phase detection autofocus pixel elements. The pair of phase detection autofocus pixel elements comprises a first phase detection autofocus pixel element according to an embodiment of the first aspect of the present invention, wherein the light shielding members of the first phase detection autofocus pixel element are all deviated in a first direction relative to the optical axis of the microlens associated with the light shielding member. The pair of phase detection autofocus pixel elements also comprises a second phase detection autofocus pixel element according to an embodiment of the first aspect of the present invention, wherein the light shielding members of the second phase detection autofocus pixel element are all deviated in a second direction relative to the optical axis of the microlens associated with the light shielding member, and the second direction is substantially opposite to the first direction. One advantage of the embodiments of the present invention is that the image sensor can provide good focus of the camera lens.

[0026] Preferably, the first phase detection autofocus pixel element and the second phase detection autofocus pixel element are positioned close to each other. Preferably, the first phase detection autofocus pixel element and the second phase detection autofocus pixel element are spaced apart from each other by a maximum of ten pixel elements, for example, a maximum of five pixel elements, or are directly adjacent to each other, for example, in contact with each other. This can result in a good comparison of the signals of the first phase detection autofocus pixel element and the second phase detection autofocus pixel element. Typically, the image sensor includes a plurality of first phase detection autofocus pixel elements and a plurality of second phase detection autofocus pixel elements. In other words, the image sensor may include a plurality of paired phase detection autofocus pixel elements. In these embodiments, the first phase detection autofocus pixel element and the second phase detection autofocus pixel element may be substantially evenly distributed within the image sensor.

[0027] Although in most cases the analysis of the two signals is performed external to the image sensor, in certain embodiments the image sensor includes a device configured to compare the signal generated by the photodiode of the first phase detection autofocus pixel element with the signal generated by the photodiode of the second phase detection autofocus pixel element. In embodiments including a plurality of pairs of phase detection autofocus pixel elements, the device may be configured to compare the signals generated by the photodiodes of the plurality of first phase detection autofocus pixel elements (i.e., the first image) with the signals generated by the photodiodes of the plurality of second phase detection autofocus pixel elements (i.e., the second image). It should be noted that the "image" formed by the signals of the PDAF pixel elements may be composed of a very limited number of pixel elements and does not necessarily constitute an image that would be appreciated by a user of a camera incorporating these pixel elements.

[0028] In addition, the image sensor may include at least one additional pair of phase detection autofocus pixel elements, for example, a plurality of pairs of phase detection autofocus pixel elements, wherein the additional pairs of phase detection autofocus pixel elements include a third phase detection autofocus pixel element according to an embodiment of the first aspect of the present invention. In these embodiments, the light shielding members of the third phase detection autofocus pixel element are all offset in a third direction relative to the optical axis of the microlens associated with the light shielding member, and the third direction is substantially vertical to the first direction. In these embodiments, the additional pairs of phase detection autofocus pixel elements also include a fourth phase detection autofocus pixel element according to an embodiment of the first aspect of the present invention, wherein the light shielding members of the fourth phase detection autofocus pixel element are all offset in a fourth direction relative to the optical axis of the microlens associated with the light shielding member, and the fourth direction is substantially opposite to the third direction. The advantage of these embodiments is that more accurate focusing can be obtained. The features of the third phase detection autofocus pixel element and the fourth phase detection autofocus pixel element can be independently as described for the first phase detection autofocus pixel element and the second phase detection autofocus pixel element, respectively.

[0029] In a third aspect, the invention relates to a camera comprising an image sensor according to an embodiment of the second aspect of the invention, the image sensor comprising means configured to compare a signal generated by a photodiode of a first phase detection autofocus pixel element with a signal generated by a photodiode of a second phase detection autofocus pixel element. The camera further comprises a camera lens. The camera is configured, for example, to include suitable means (e.g. an actuator) for moving the camera lens along an optical axis of the camera lens based on a comparison of the signal generated by the photodiode of the first phase detection autofocus pixel element with the signal generated by the photodiode of the second phase detection autofocus pixel element.

[0030] In a preferred embodiment, the comparison is performed between a signal representing the first image generated by the photodiodes of the plurality of first phase detection autofocus pixel elements and a signal representing the second image generated by the photodiodes of the plurality of second phase detection autofocus pixel elements. If a shift of the first image relative to the second image is detected, the camera lens may be moved to bring the first image into coincidence with the second image.

[0031] Alternatively, the device for moving the camera lens can be configured to reduce (preferably, minimize) the difference between the photodiode signal of the first phase detection autofocus pixel element and the signal generated by the photodiode of the second phase detection autofocus pixel element. For example, the comparison can include determining whether the signal generated by the photodiode of the first phase detection autofocus pixel element in the pair of phase detection autofocus pixel elements has a predefined offset compared to the signal generated by the photodiode of the second phase detection autofocus pixel element in the pair of phase detection autofocus pixel elements. If it is determined that this is not the case, the camera lens can be moved until the signal exhibits the predefined offset.

[0032] In a fourth aspect, the present invention relates to the use of a phase detection autofocus pixel element according to an embodiment of the first aspect of the present invention for focusing a camera lens.

[0033] Particular and preferred aspects of the invention are set out in the accompanying independent and dependent claims. Features in the dependent claims may be combined with features of the independent claim and features of other dependent claims as appropriate and not limited to those explicitly set out in the claims.

[0034] The above and other features, characteristics and advantages of the present invention will become apparent from the following detailed description in conjunction with the accompanying drawings, which illustrate the principles of the present invention by way of example. This description is for illustrative purposes only and does not limit the scope of the present invention. The reference figures cited below refer to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1A is a schematic diagram of a vertical cross-section of a camera lens and an image sensor according to the prior art, wherein the image sensor includes a phase detection autofocus pixel element, the phase detection autofocus pixel element includes a first photodiode S1 and a second photodiode S2, wherein the camera lens focuses light from a point on an object on a microlens of the image sensor.

[0036] Figure 1B is a schematic diagram of a vertical cross-section of a camera lens and an image sensor according to the prior art, the image sensor including a phase detection autofocus pixel element, the phase detection autofocus pixel element including a light shield, wherein the camera lens focuses light on a microlens of the image sensor.

[0037] Figure 2 is a schematic diagram of a vertical cross-section of a camera lens and an image sensor according to the prior art, the image sensor including a phase detection autofocus pixel element, the phase detection autofocus pixel element including a first photodiode S1 and a second photodiode S2, wherein the camera is in a defocus state.

[0038] Figure 3 ] is a diagram of images "S1 image" and "S2 image" generated by first and second light beams incident on a plurality of first photodiodes S1 and a plurality of second photodiodes S2, respectively.

[0039] Figure 4A Schematic diagram of a vertical cross section of a pair of phase detection autofocus pixel elements according to the prior art, wherein a light beam with a specific incident angle is incident on a microlens of the phase detection autofocus pixel element. The illustration on the left indicates the direction of the incident angle.

[0040] Figure 4B 3 is a graph showing the quantum efficiency of a conventional (non-PDAF) pixel element, a phase detection autofocus pixel element that is not optimized according to the prior art structure, and a phase detection autofocus pixel element that is optimized according to the prior art structure as a function of the incident angle.

[0041] Figure 5 is a schematic diagram of a partial top view of an image sensor according to an embodiment of the present invention.

[0042] Figure 6 is a partial vertical cross-sectional view of an image sensor according to an embodiment of the present invention.

[0043] Figure 7 is a schematic diagram of a vertical cross section of a camera according to an embodiment of the present invention.

[0044] Figure 8 is a chart showing modeling results of a series of phase detection auto-focus pixel elements, wherein the series of phase detection auto-focus pixel elements include phase detection auto-focus pixel elements of the prior art and phase detection auto-focus pixel elements according to an embodiment of the present invention.

[0045] In different drawings, the same reference symbols identify the same or similar elements. DETAILED DESCRIPTION

[0046] The present invention will be described with respect to specific embodiments and with reference to certain drawings, but the invention is not limited thereto but only by the claims. The drawings are illustrative and non-limiting only. In the drawings, for ease of illustration, the dimensions of some elements may be exaggerated and not drawn to scale. The dimensions and relative dimensions do not correspond to reductions in actual implementation of the invention.

[0047] The terms "first", "second", "third", etc. in the specification and claims are used to distinguish similar elements and are not necessarily used to describe a sequence in time, space, order or any other manner. It should be understood that these terms can be interchanged under appropriate circumstances, and the embodiments of the invention described herein are capable of operating in sequences other than those described or shown herein.

[0048] In addition, the terms "top", "bottom", "above", "below", etc. in the specification and claims are used for descriptive purposes only and are not necessarily used to describe relative positions. It is understood that these terms are interchangeable under appropriate circumstances and that the embodiments of the invention described herein are capable of operation in other orientations than described or illustrated herein.

[0049] It should be noted that the term "comprising" used in the claims and the description should not be interpreted as being limited to the means listed thereafter; it does not exclude other elements or steps. Therefore, it should be interpreted as the presence of the stated features, wholes, steps or components, but does not exclude the presence or addition of one or more other features, wholes, steps or components or groups thereof. Therefore, the term "comprising" covers the case where only the stated features are present as well as the case where these features and one or more other features are present. Therefore, according to the present invention, the word "comprising" also includes an embodiment in which no other components are present. Therefore, the scope of the expression "a device comprising devices A and B" should not be interpreted as being limited to a device consisting only of components A and B. This means that, for the purposes of the present invention, the only relevant components of the device are A and B.

[0050] Similarly, it should be noted that the term "coupled" should not be interpreted as being limited to only direct connections. The terms "coupled" and "connected" and their derivatives may be used. It should be understood that these terms are not synonymous with each other. Therefore, the scope of the expression "device A is coupled to device B" should not be limited to devices or systems where the output of device A is directly connected to the input of device B. This means that there is a path between the output of A and the input of B, which may be a path that includes other devices or components. "Coupled" may mean that two or more elements are in direct physical or electrical contact, or that two or more elements are not in direct contact with each other but still cooperate or interact with each other.

[0051] References in this specification to "one embodiment" or "an embodiment" mean that a particular feature, structure, or characteristic described in connection with that embodiment is included in at least one embodiment of the present invention. Thus, the phrases "in one embodiment" or "in an embodiment" appearing in various places in this specification do not necessarily all refer to the same embodiment, but may refer to the same embodiment. Furthermore, particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments, as will be apparent to one of ordinary skill in the art from this disclosure.

[0052] Similarly, it should be understood that in describing exemplary embodiments of the invention, various features of the invention are sometimes grouped together to form a single embodiment, figure, or description in order to simplify the disclosure and aid in understanding one or more of the various inventive aspects. However, this method of disclosure should not be interpreted as reflecting an intention that the claimed invention requires more features than are expressly recited in each claim. On the contrary, as reflected in the appended claims, inventive aspects are present in all of the features of a single, previously disclosed embodiment. Therefore, the claims that follow the detailed description are hereby expressly incorporated into this detailed description, with each claim independently serving as a separate embodiment of the invention.

[0053] In addition, although some embodiments described herein include some features included in other embodiments but do not include other features, combinations of features of different embodiments should also be within the scope of the present invention and form different embodiments, as understood by those skilled in the art. For example, in the appended claims, any claimed embodiment can be used in any combination.

[0054] In addition, some of the embodiments described herein are combinations of methods or method elements, which can be implemented by a processor of a computer system or other devices that perform the function. Therefore, a processor with instructions required to perform such methods or method elements constitutes a device that performs the method or method elements. In addition, the elements of the device embodiments described herein are examples of devices that perform the functions performed by the elements to implement the present invention.

[0055] In the description provided herein, many specific details are set forth. However, it should be understood that embodiments of the present invention can be implemented without these specific details. In other cases, well-known methods, structures, and techniques are not shown in detail to avoid confusing the understanding of this description.

[0056] The present invention will now be described by a detailed description of several embodiments of the present invention. Obviously, other embodiments of the present invention can be configured according to the knowledge of those skilled in the art without departing from the technical teaching of the present invention, and the present invention is only limited by the terms of the appended claims.

[0057] In a first aspect, the present invention relates to a phase detection autofocus pixel element. The phase detection autofocus pixel element comprises a photodiode and a plurality of microlenses, the plurality of microlenses being used to concentrate light incident on each of the microlenses onto the photodiode. The phase detection autofocus pixel element also comprises a light shield for each microlens, the light shield being associated with each microlens, the light shield being used to block a portion of light transmitted by the microlens toward the photodiode. The light shield is offset relative to the optical axis of the microlens to which the light shield is associated along the same offset direction.

[0058] In a second aspect, the present invention relates to an image sensor, the image sensor comprising a pair of phase detection autofocus pixel elements. The pair of phase detection autofocus pixel elements comprises a first phase detection autofocus pixel element according to an embodiment of the first aspect of the present invention, wherein the light shielding members of the first phase detection autofocus pixel element are all offset in a first direction relative to the optical axis of the microlens associated with the light shielding member. The pair of phase detection autofocus pixel elements also comprises a second phase detection autofocus pixel element according to an embodiment of the first aspect of the present invention, wherein the light shielding members of the second phase detection autofocus pixel element are all offset in a second direction relative to the optical axis of the microlens associated with the light shielding member, and the second direction is substantially opposite to the first direction.

[0059] refer to Figure 5 , Figure 5 FIG. 6 is a schematic diagram of a top view of a portion of an image sensor 6 according to an embodiment of the present invention. Figure 6 , Figure 6 For along Figure 5 Schematic diagram of a vertical cross-section of a portion of an image sensor 6 indicated by a dashed line in FIG. In the example shown, the portion of the image sensor 6 includes a plurality of pixel elements, the plurality of pixel elements including two phase detection autofocus pixel elements 1 and 10 according to an embodiment of the present invention, and six conventional pixel elements 100, i.e., conventional pixel elements are pixel elements configured to detect light and thereby detect an image but not to perform phase detection autofocus. In the embodiment shown, the conventional pixel elements and the PDAF pixel elements have microlenses of different sizes. However, this is not necessary for the present invention, and all microlenses or substantially all microlenses may be equal to one another. Microlenses of different sizes or shapes are possible, but generally make the production process more complicated.

[0060] Each of the two phase-detection autofocus pixel elements 1, 10 includes a single photodiode 2, 20. In the illustrated example, the first phase-detection autofocus pixel element 1 of the two phase-detection autofocus pixel elements 1, 10 includes four microlenses 3, which are used to focus the light incident on each microlens 3 in the microlenses through a transparent planarization layer 72 and an optional color filter 71 to the photodiode 2 of the first phase-detection autofocus pixel element 1. In the illustrated example, the second phase-detection autofocus pixel element 10 of the two phase-detection autofocus pixel elements 1, 10 includes four microlenses 30, which are used to focus the light incident on each microlens 30 in the microlenses through a transparent planarization layer 72 and an optional color filter 71 to the photodiode 20 of the second phase-detection autofocus pixel element 10. Here, the microlenses 3 and 30 in each phase detection autofocus pixel element 1, 10 are arranged in a square array of 2×2 microlenses 3, 30, that is, the microlenses 3 and 30 are arranged in two rows 32 and two columns 33. In general, each autofocus pixel element may include a plurality of microlenses arranged in a regular or irregular manner, preferably a rectangular array of N×M microlenses, preferably a square array of N×N microlenses.

[0061] In the example shown, each of the regular pixel elements 100 includes a single microlens 300 for concentrating (eg, focusing) light through a transparent planarization layer 72 and an optional color filter 71 onto the photodiode 200 of the regular pixel element 100 .

[0062] Each microlens 3, 30, 300 of a specific pixel element 1, 10, 100 can ensure that light incident on the microlens 3, 30, 300 propagates to the photodiode 2, 20, 200 of the specific pixel element 1, 10, 100, thereby preventing the light from propagating to adjacent pixel elements 1, 10, 100. In addition, as described in the background of the present invention, preferably, the microlens 3, 30 of the phase detection autofocus pixel element 1, 10 focuses light having a specific incident angle in the plane of the light shield 4, 40. In other words, preferably, the microlens 3, 30 of the phase detection autofocus pixel element 1, 10 has a focal length that is substantially equal to the distance between the microlens 3, 30 and the light shield 4, 40 associated with the microlens 3, 30.

[0063] Although in the example shown, each of the conventional pixel elements 100 includes a single microlens 300, alternatively, each of the conventional pixel elements 100 may also include a plurality of microlenses, such as a regular array of four microlenses. The number and order of the microlenses may be the same as or different from the number and order of the microlenses of the autofocus pixel element. The microlenses of the conventional pixel element 100 may have substantially the same shape and size as the microlenses 3, 30 of the phase detection autofocus pixel elements 1, 10. This may facilitate the manufacture of the image sensor 6.

[0064] The color filter 71 can block light that is not desired to be detected so that it cannot reach the photodiode 2, 20, 200, for example, the light is not in the visible spectrum but causes the photodiode 2, 20, 200 to produce a signal undesirably. In addition, the color filter 71 can only allow a limited portion of the visible spectrum (e.g., red or blue or green) to pass. For example, different conventional pixel elements 100 can have different color filters 71 to allow different portions of the visible spectrum to pass, so that the conventional pixel element 100 can be used as a color pixel element.

[0065] The transparent planarization layer 72 can provide a uniform and flat top surface 70 on which the microlenses 3, 30, 300 are formed. Therefore, the bottom surface of the microlenses 3, 30, 300 can be substantially flat, thereby facilitating good focusing of the microlenses 3, 30, 300.

[0066] In this example, each microlens 3, 30, 300 has a rounded rectangular parallelepiped shape. However, the microlens 3, 30, 300 may have any shape, for example, each microlens 3, 30, 300 may be a spherical lens.

[0067] Each microlens 3 of the first phase detection autofocus pixel element 1 is associated with a light shield 4 for blocking a portion of the light transmitted by the microlens 3 toward the photodiode 2 of the first phase detection autofocus pixel element 1. Here, the light shield 4 of the first phase detection autofocus pixel element 1 is offset by a distance d relative to the optical axis 31 of the microlens 3 to which the light shield 4 is associated along the same first offset direction X. In the example shown, the light shield 4 associated with the microlens 3 of the first phase detection autofocus pixel element 1 blocks substantially all of the following light transmitted by the associated microlens 3: these lights would be collected by the photodiode 2 located on one side of the optical axis 31 in the first offset direction X without the light shield 4. Similarly, each microlens 30 of the second phase detection autofocus pixel element 10 is associated with a light shield 40 for blocking a portion of the light transmitted by the microlens 30 toward the photodiode 20 of the second phase detection autofocus pixel element 10. Here, the light shield 40 is offset by a distance d relative to the optical axis 310 of the microlens 30 associated with the light shield 40 in the same second offset direction -X opposite to the first offset direction X. In the example shown, the light shield 40 associated with the microlens 30 of the second phase detection autofocus pixel element 10 blocks substantially all of the following light transmitted by the associated microlens 30: these lights would be collected by the photodiode 20 located on one side of the optical axis 310 in the second offset direction -X in the absence of the light shield 40. As can be seen in Figure 5 and Figure 6 As observed, in the example shown, each light shield 4, 40 covers a complete portion of the photodiode 1, 10 that overlaps half of the associated microlens 3, 30 in the following position, while exposing the remaining portion of the photodiode 1, 10: the complete portion is located on the side of the associated microlens 3, 30 located on the optical axis 31, 310 in the corresponding offset direction X, -X. Figure 5 and Figure 6 In the embodiment shown, all light shields have the same width. This is not necessarily the case. For PDAF pixel elements in the center of the image sensor, their widths should be the same, while for pixel elements near the edge of the imager, the widths can be different.

[0068] In the example shown, each light shield 4, 40 has substantially the same shape and size. The light shield 4, 40 is offset by substantially the same distance d relative to the optical axis 31, 310 of the microlens 3, 30 to which it is associated. Here, the distance d may be the distance between the center of the light shield 4, 40 and the optical axis 31, 310 of the microlens 3, 30 to which it is associated. In addition, the light shield 4, 40 is positioned at the same distance from the associated microlens 3, 30. Although in Figure 5In the embodiment, the light shielding members 4, 40 are shown as being separated from each other, but this is not necessary. For example, alternatively, the light shielding members 4, 40 that are in physical contact with each other can be integrated with each other, which can facilitate manufacturing.

[0069] Although in the example shown, the light shields 4, 40 are offset in the X direction, the offset can be any horizontal direction, that is, any direction in the plane of the image sensor 6, that is, the plane is a plane perpendicular to the optical axis 31, 310. For example, alternatively, the offset can be in the Y direction perpendicular to X. In this case, the light shields 4, 40 are usually rotated 90° in the X, Y plane. The image sensor may include: a first pair of phase detection autofocus pixel elements 1, 10, which include light shields 4, 40 offset in the X direction; and a second pair of phase detection autofocus pixel elements, which include light shields offset in the Y direction perpendicular to the X direction. This can improve focusing accuracy. In addition, in other embodiments, the third pair of PDAF pixel elements may have the following light shields: the light shield can be rotated at 45° in the X, Y plane compared to the direction of the light shields of the first pair of PDAF pixel elements or the second pair of PDAF pixel elements. In other alternative embodiments, other rotation angles of light shields of some PDAF pixel element pairs can also be achieved.

[0070] exist Figure 6 In the embodiment shown, the phase detection autofocus pixel elements 1, 10 (like the conventional pixel element 100) have color filters. It should be noted that if color filters are used in the phase detection autofocus pixel elements, the PDAF pixel element pair has the same color filter (e.g., R, G or B).

[0071] In a third aspect, the invention relates to a camera comprising an image sensor according to an embodiment of the second aspect of the invention, the image sensor comprising means configured to compare a signal generated by a photodiode of a first phase detection autofocus pixel element with a signal generated by a photodiode of a second phase detection autofocus pixel element. The camera further comprises a camera lens. The camera is configured to move the camera lens along an optical axis of the camera lens based on the comparison of the signal generated by the photodiode of the first phase detection autofocus pixel element with the signal generated by the photodiode of the second phase detection autofocus pixel element.

[0072] Generally, a camera according to an embodiment of the present invention may have similar functions and similar features as cameras at the prior art level, except that each phase detection autofocus pixel element according to an embodiment of the present invention includes more than one microlens and a light shield associated with each microlens, rather than a single microlens and a light shield associated with the phase detection autofocus pixel element at the prior art level.

[0073] refer to Figure 7 , Figure 7 A camera 8 according to an embodiment of the invention is shown. The camera 8 comprises an image sensor 6, of which only a part is shown. The image sensor 6 comprises a plurality of pairs of phase detection autofocus pixel elements 1,10.

[0074] The image sensor 6 includes a comparison device 60 configured to compare a signal (e.g., a first image) generated by a photodiode 2 of a first phase detection autofocus pixel element 1 with a signal (e.g., a second image) generated by a photodiode 2 of a second phase detection autofocus pixel element 10 of a plurality of pairs of phase detection autofocus pixel elements 1, 10. Specifically, the comparison device 60 is coupled to the photodiode 2 of each first phase detection autofocus pixel element 1 and the photodiode 20 of each second phase detection autofocus pixel element 10 in a communication manner to receive signals from the photodiodes 2, 20 of the phase detection autofocus pixel elements 1, 10. Here, it is assumed that the signal generated in each photodiode 2, 20 is proportional to the amount of light incident on the photodiode 2, 20. The comparison device 60 may include a processor for performing the comparison.

[0075] In addition, the camera 8 further comprises a collecting device (not shown) for collecting the signal generated by the photodiode 200 of the regular pixel element 100. The comparing device 60 for the comparison and the collecting device for collecting the signal generated by the photodiode 200 of the regular pixel element 100 may be the same device, such as the same processor, or they may be different devices, such as different processors.

[0076] The camera 8 further comprises a camera lens 5. Similar to the prior art and as described elsewhere in the specification, a comparison device 60 can compare signals from the first phase detection autofocus pixel element 1 and the second phase detection autofocus pixel element 10, and the comparison device 60 can cause the actuator 51 to move the camera lens 5 along the optical axis 50 of the camera lens 5 based on the comparison. Specifically, partially repeating the explanation in the background of the invention, it can be assumed that light from each point 801, 802 on the object 80 is split into a first light beam L1 and a second light beam L2, thereby propagating through different halves of the camera lens 5.

[0077] When camera 8 is said to be focused relative to object 80, as in Figure 7 As shown, the light collected by the camera lens 5 from each specific point 801, 802 on the object 80 is focused on the plane of the microlens 3, 30, 300. In this way, the camera lens 5 projects a clear image of the object 80 onto the image sensor 6.

[0078] For simplicity, Figure 7 , the propagation paths of the light beams L1 and L2 from two different adjacent points 801 and 802 on the object 80 are shown. Similar to the phase detection autofocus pixel elements of the prior art, in the ideal case where the microlens has the best focusing ability, when the camera 8 is focused, for the light beams L1 and L2 focused on the microlens 3 of one of the first phase detection autofocus pixel elements 1 (for example, the light beams L1 and L2 from the first point 801), the first light beam L1 is detected by the photodiode 2 of the first phase detection autofocus pixel element 1, and the light shield 4 associated with the microlens 3 blocks the second light beam L2. For the light beams L1 and L2 focused on the microlens 3 of one of the second phase detection autofocus pixel elements 10 (for example, the light beams L1 and L2 from the second point 802), the second light beam L2 is detected by the photodiode 20 of the second phase detection autofocus pixel element 10, and the light shield 40 associated with the microlens 30 blocks the first light beam L1.

[0079] Thus, when the camera 8 is focused, a first image of the object 80 generated by the first phase detection autofocus pixel element 1 has a predefined offset compared to a second image of the object generated by the second phase detection autofocus pixel element 10. The predefined offset takes into account the physical offset between the two centers of the PDAF pixel element pair.

[0080] On the contrary, when the camera 8 is out of focus relative to the object 80, the first light beam L1 and the second light beam L2 from each point 801, 802 on the object 80 are focused at a point far away from the plane of the microlens 3, 30, 300, so that the first light beam L1 and the second light beam L2 from each point 801, 802 on the object 80 are incident on different pixel elements 1, 10, 100. Figure 3 As shown and similar to what is described in the background of the invention, the first image ("S1 image") generated by the first phase detection autofocus pixel element 1 detecting the first light beam L1 and the second image ("S2 image") generated by the second phase detection autofocus pixel element 10 detecting the second light beam L2 will be offset relative to each other by more than a predefined offset. When the camera 8 is out of focus, the actuator 51 can move the camera lens 5 so that the first image and the second image overlap, thereby focusing the camera 8. Figure 3If the S1 image is in front of the S2 image, a back focus situation occurs; if the S2 image is in front of the S1 image (not shown), a front focus situation occurs. Depending on what happens, the actuator can decide in which direction the camera lens must move to focus.

[0081] The inset in the upper right corner indicates the direction of the incident angle α of the light incident on the microlens 3, 30. The incident angle α is in a plane parallel to the optical axis 31, 310 of the microlens 3, 30 and the X axis, and the incident angle α is relative to normal incidence, that is, along the optical axis 31, 310 of the microlens 3, 30. The direction of the incident light having an X component pointing in the X direction has a negative incident angle α, and the direction of the incident light having an X component pointing in the -X direction has a positive incident angle α.

[0082] The above idealized function means that the first phase detection autofocus pixel element 1 has perfect selectivity for the first light beam L1, and the second phase detection pixel element 10 has perfect selectivity for the second light beam L2. For the first phase detection autofocus pixel element 1, in the example shown, all light incident on each microlens 3 of each first phase detection autofocus pixel element 1 at an angle α less than 0° (i.e., the second light beam L2) is blocked by the light shield 4 associated with the microlens 3, and all light incident on the microlens 3 at an angle α greater than 0° (i.e., the first light beam L1) is detected by the photodiode 2 of the first phase detection autofocus pixel element 1, thereby achieving the above perfect selectivity. Similarly, for the second phase detection autofocus pixel element 10, in the example shown, all light incident on each microlens 30 of each second phase detection autofocus pixel element 10 at an angle α greater than 0° is blocked by the light shielding member 40 associated with the microlens 30, while all light incident on the microlens 30 at an angle α less than 0° is detected by the photodiode 20 of the second phase detection autofocus pixel element 10, thereby achieving the above-mentioned perfect selectivity.

[0083] refer to Figure 8 , Figure 8Graph showing the relationship between the simulated quantum efficiency and the incident angle α for different large first phase detection autofocus pixel elements, where the photodiodes of different pixel elements have the same size. The simulation data was obtained by TCAD simulation (Ansys Lumerical optoelectronic device simulator). The curve marked with diamonds is the angular dependent quantum efficiency of the large first phase detection autofocus pixel element, which, according to the prior art, only includes a single microlens with a height of 2.7μm and a single light shield associated with the single microlens. Due to the large size of the phase detection autofocus pixel elements in the prior art (the pixel element in the simulation is 7.2μm), the components that form the pixel elements are performed at the edge of processing capabilities. For example, the shape of the microlens is particularly poor, because in this case, the height and radius of curvature of the microlens are so large that known manufacturing technologies cannot produce well-shaped microlenses. Therefore, the microlens has a poor focusing effect on the plane of the light shield for light at each incident angle. In fact, from Figure 8 It can be clearly seen in FIG. 1 that, according to the prior art, the light shield of the first phase detection autofocus pixel element cannot effectively block incident light with an incident angle α below zero, compared with incident light with an incident angle α greater than zero. This poor selectivity results in poor contrast between the first image and the second image generated by such a large first phase detection autofocus pixel element and the second phase detection autofocus pixel element of the prior art, resulting in poor autofocus function.

[0084] For comparison, the general curve shows the angle-dependent quantum efficiency of a conventional pixel element having a single microlens with a height of 2.7 μm and no light shielding member. Therefore, the conventional pixel element is equally sensitive to light with a positive incident angle and light with a negative incident angle, in other words, does not show any selectivity.

[0085] exist Figure 8In the figure, the curve marked with black squares corresponds to a large phase detection autofocus pixel element (7.2μm width) according to an embodiment of the present invention, which includes a 2×2 microlens array, each microlens has a height of 2.7μm, and each microlens has an associated light shield that blocks all light that propagates through the microlens in a first direction of the optical axis of the microlens toward the portion of the photodiode of the phase detection autofocus pixel element. It should be noted that the single microlens and the 2×2 microlens array used in the different simulations have the same thickness of 2.7μm. The same thickness of the microlenses at a smaller spacing results in a larger curvature of the microlenses and therefore a higher focusing ability, so that the smaller microlenses are better able to focus light at the light shield (for a given flattening and a given color filter thickness). The curve marked with triangles represents the case of a similar phase detection autofocus pixel element according to an embodiment of the present invention, but with 4×4 microlenses (with associated light shields), each microlens has a height of 1.8μm. The curve marked with circles represents the case of a similar phase detection autofocus pixel element according to an embodiment of the present invention, but with 3×3 microlenses (with associated light shields), each of which has a height of 1.2 μm. It can be observed that each exemplary first phase detection autofocus pixel element according to an embodiment of the present invention has very good selectivity for a light beam with a positive incident angle α, wherein almost all light with a negative incident angle α is blocked by the light shield, and a good signal is obtained from light with a positive incident angle α.

[0086] Therefore, when using a phase detection autofocus pixel element according to an embodiment of the present invention, wherein each pixel element includes a plurality of microlenses, each microlens having a light shield associated with the microlens, the processing steps for forming the microlenses and the optical stack can be performed within an optimized range even when the pixel element is large and the photodiode is large. Therefore, for an image sensor including large pixel elements, and therefore an image sensor including large phase detection autofocus pixel elements, light at each incident angle can be well focused by the microlenses in the plane of the light shield, thereby having good selectivity and therefore good autofocus function.

[0087] It should be understood that although the preferred embodiments, specific constructions and configurations and materials of the device according to the present invention have been discussed herein, various changes or modifications in form and detail may be made without departing from the scope of the present invention. Steps may be added or deleted to the method within the scope of the present invention.

Claims

1. A phase detection auto-focus pixel element (1), the phase detection auto-focus pixel element comprising: Photodiode (2), a plurality of microlenses (3), the plurality of microlenses being used to focus light incident on each of the microlenses (3) onto the photodiode (2), and A light shield (4) for each microlens (3), the light shield (4) being associated with each microlens, the light shield (4) being used to block part of the light transmitted by the microlens (3) toward the photodiode (2), wherein the light shield (4) is offset along the same offset direction (X) relative to the optical axis (31) of the microlens (3) to which the light shield is associated.

2. The phase detection autofocus pixel element (1) according to claim 1, wherein: A plurality of microlenses (3) are arranged in a square array.

3. The phase detection autofocus pixel element (1) according to claim 2, wherein: The square array of microlenses (3) comprises rows and columns of microlenses, and each row (32) and each column (33) comprises at least two microlenses (3).

4. The phase detection autofocus pixel element (1) according to claim 1, wherein: The shapes and sizes of the plurality of microlenses (3) are substantially the same.

5. The phase detection autofocus pixel element (1) according to claim 1, wherein: The light shield (4) associated with the microlens (3) blocks substantially all of the light transmitted by the associated microlens (3) which, in the absence of the microlens (3), would be collected by the photodiode (2) located on one side of the optical axis (31) in the offset direction (X).

6. The phase detection autofocus pixel element (1) according to claim 1, wherein: Each light shielding member (4) is formed of metal.

7. The phase detection autofocus pixel element (1) according to claim 1, wherein: The light shields (4) have substantially the same size, and wherein the light shields (4) are offset by substantially the same distance relative to the optical axis (31) of the microlens (3) to which they are associated.

8. An image sensor (6), comprising a pair of phase detection autofocus pixel elements (1, 10), the pair of phase detection autofocus pixel elements comprising: A first phase detection autofocus pixel element (1) according to any one of claims 1 or 2 or 3 or 4 or 5 or 6 or 7, wherein the light shielding members (4) of the first phase detection autofocus pixel element (1) are offset in a first offset direction (X) relative to an optical axis (31) of a microlens (3) associated with the light shielding member, and A second phase detection autofocus pixel element (10) according to any one of claims 1 or 2 or 3 or 4 or 5 or 6 or 7, wherein the light shielding members (40) of the second phase detection autofocus pixel element (10) are offset along a second offset direction (-X) relative to the optical axis (310) of the microlens (30) associated with the light shielding member, and the second offset direction (-X) is substantially opposite to the first offset direction (X).

9. An image sensor (6) according to claim 8, comprising a device (60) configured to compare a signal generated by a photodiode (2) of the first phase detection autofocus pixel element (1) with a signal generated by a photodiode (20) of the second phase detection autofocus pixel element (10).

10. A camera (8), comprising an image sensor (6) according to claim 9, the camera further comprising a camera lens (5), in, The camera is configured to move the camera lens (5) along an optical axis (50) of the camera lens (5) based on the comparison of the signal generated by the photodiode (2) of the first phase detection autofocus pixel element (1) and the signal generated by the photodiode (20) of the second phase detection autofocus pixel element (10).

11. Use of the phase detection auto-focus pixel element (1) according to any one of claims 1 or 2 or 3 or 4 or 5 or 6 or 7 for focusing a camera lens (5).

Images