Optical sensor, optical sensing method, and electronic device

Abstract

To provide an optical sensor capable of performing highly accurate optical sensing of a scene.SOLUTION: The optical sensor includes a unit D1 including x blocks 11, for example, three (x = 3) blocks a, b, and c, each having a plurality of pixels 12 arranged in a first direction 11A in a plan view. The pixels 12 are arranged at a pixel pitch D1 in the first direction P1. The three blocks a, b, and c are arranged side by side in a second direction D1 orthogonal to the first direction D2, and are arranged to be shifted from each other by P1 / 3 in the first direction D1. For example, the light receiving elements 11A and 10b each including the units 10a corresponding to the number of stages of the TDI are arranged so as to partially overlap each other in the D1 in the first direction, and the optical sensing is performed using the blocks a and b in which the positional deviation of the pixels 12 is minimized. In addition, by increasing the size of each of the light receiving elements 10a and 10b in the second direction D2, inclination at the time of mounting, poor connection, and the like are suppressed.SELECTED DRAWING: Figure 10

Description

[Technical Field]

[0001] The present invention relates to an optical sensor, an optical sensing method, and an electronic device. [Background technology]

[0002] A document reading device is known in which multiple line sensors, each with multiple light receiving elements arranged in a row, are arranged in a staggered pattern with the ineffective light receiving elements at each end aligned, and the output of the line sensor that reads first is delayed by a time corresponding to the interval between it and the line sensor that reads next (Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 60-31357 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in an optical sensor using a light receiving element in which a plurality of pixels including a light receiving portion are arranged in a one-dimensional array, the configuration of the light receiving element may make it difficult to perform high-precision optical sensing of a scene, which makes it difficult to obtain a high-resolution image of the scene.

[0005] In one aspect, the present invention aims to provide an optical sensor capable of performing highly accurate optical sensing of a scene. [Means for solving the problem]

[0006] In one aspect, an optical sensor is provided that includes x blocks (x is an integer greater than or equal to 2) each having a plurality of pixels arranged in a first direction in a planar view, the plurality of pixels being arranged at a first pixel pitch in the first direction in a planar view, and the x blocks being arranged side by side in a second direction perpendicular to the first direction in a planar view, and being shifted from each other in the first direction by a distance of 1 / x of the first pixel pitch.

[0007] In another aspect, there is provided an optical sensing method using the optical sensor as described above, and an electronic device including the optical sensor as described above. [Effects of the Invention]

[0008] In one aspect, it becomes possible to realize an optical sensor capable of performing highly accurate optical sensing of a scene. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 2 is a diagram illustrating an example of a light receiving element. [Figure 2] 1 is an example of a circuit diagram of an optical sensor. [Figure 3] FIG. 2 is a diagram illustrating a configuration example of an optical sensor. [Figure 4] FIG. 2 is a diagram illustrating an example of an optical sensor according to the first embodiment. [Figure 5] 2A and 2B are diagrams illustrating an example of a light receiving element according to the first embodiment. [Figure 6] FIG. 2 is a diagram illustrating a first configuration example of a module according to the first embodiment. [Figure 7] FIG. 4 is a diagram illustrating a second configuration example of the module according to the first embodiment. [Figure 8] 5A to 5C are diagrams illustrating an example of a method for manufacturing the module according to the first embodiment. [Figure 9] 10A and 10B are diagrams illustrating an example of a light receiving element according to a second embodiment. [Figure 10] 10A and 10B are diagrams illustrating an example of the arrangement of light receiving elements according to the second embodiment. [Figure 11] 10A and 10B are diagrams (part 1) for explaining an example of an optical sensing method using a light receiving element according to a second embodiment. [Figure 12] FIG. 10 is a diagram (part 2) for explaining an example of an optical sensing method using a light receiving element according to the second embodiment. [Figure 13] 10A and 10B are diagrams illustrating an example of a light receiving element according to a third embodiment. [Figure 14] FIG. 10 is a diagram illustrating an example of an electronic device according to a fourth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0010] First, the light receiving element provided in the optical sensor will be described. Figure 1 is a diagram illustrating an example of a light-receiving element. Figure 1(A) shows a schematic cross-sectional view of a main part of an example of a light-receiving element. Figure 1(B) shows a schematic band diagram of the light-receiving element.

[0011] The light receiving element 100 shown in FIG. 1A is an example of a light receiving element that is sensitive to light in a predetermined wavelength band, for example, infrared light. The light receiving element 100 includes a plurality of pixels 110. Each pixel 110 includes a light receiving section 120, and a first electrode 130 and a second electrode 140 that are arranged on either side of the light receiving section 120. The first electrode 130 is a common electrode shared by the plurality of pixels 110. The second electrode 140 is an individual electrode that is individual to each pixel 110. The light receiving section 120 and the second electrode 140 are separated for each pixel 110 by, for example, a pixel separation groove 111. The second electrode 140 is used to output a signal (charge such as electrons) generated in the light receiving section 120.

[0012] The light receiving section 120 includes, for example, a light absorption layer 121 and a hole barrier layer 122. The light absorption layer 121 is a light absorption layer that is sensitive to light such as infrared light. The hole barrier layer 122 is provided between the light absorption layer 121 and the second electrode 140. For example, the light receiving section 120 has a Type II Super Lattice (T2SL) structure formed by combining semiconductors such as InAs (indium arsenide), GaSb (gallium antimony), and AlSb (aluminum antimony). Alternatively, the light receiving section 120 may be made of HgCdTe (mercury cadmium telluride). The light receiving section 120 is formed to have a predetermined conductivity type and impurity concentration.

[0013] In the light-receiving element 100, light is incident on the light-receiving section 120 and absorbed by the light-absorbing layer 121, generating electron-hole pairs in the light-absorbing layer 121. When reading this as a signal, for example, a bias is applied so that the first electrode 130 is at a low potential and the second electrode 140 is at a high potential. As a result, as shown in FIG. 1(B), of the electron-hole pairs generated in the light-absorbing layer 121, the hole (+) is transported toward the first electrode 130, and the electron (-) is transported toward the second electrode 140. In this case, the transport of electrons toward the first electrode 130 and the transport of holes toward the second electrode 140 are restricted by the hole barrier layer 122.

[0014] The light receiving element 100 is connected to a signal readout circuit. For example, the charges (electrons) transported to the second electrode 140 are output to the signal readout circuit through the second electrode 140, and the amount of charge is read out by the signal readout circuit. This process is performed for each pixel 110 of the light receiving element 100, and light incident from the scene and absorbed by the light receiving element 100 and its image are detected.

[0015] Figure 2 is an example of a circuit diagram for an optical sensor. The optical sensor 200 has a light receiving element 100 including a light receiving section 120 and a signal readout circuit 150 connected thereto.

[0016] The signal readout circuit 150 includes a reset transistor 160 having one load terminal connected to a reset level Vrst of a predetermined potential, and a capacitor 170 connected to the other load terminal of the reset transistor 160. The signal readout circuit 150 further includes a storage transistor 180 having one load terminal connected to a connection node between the reset transistor 160 and the capacitor 170. The other load terminal of the storage transistor 180 is connected to the light-receiving element 100. In the light-receiving element 100, an electrode (the second electrode 140) provided on one side of the light-receiving section 120 is connected to the storage transistor 180, and an electrode (the first electrode 130) provided on the other side of the light-receiving section 120 is set to a predetermined potential V0.

[0017] In the optical sensor 200, the reset transistor 160 and the storage transistor 180 of the signal readout circuit 150 are both turned off, and the system is prepared to detect charge generated in the light-receiving section 120 of the light-receiving element 100 by absorption of light such as infrared rays. When detecting charge, the reset transistor 160 of the signal readout circuit 150 is turned on, and the potential of the capacitor 170 is reset to an initial value. When the reset transistor 160 is turned off and the storage transistor 180 is turned on, and a predetermined bias is applied to the light-receiving element 100, the charge in the light-receiving section 120 is transported to and stored in the capacitor 170. This causes the potential of the capacitor 170 to change from its initial value, and this change is read out by the potential detection circuit 151 and detected as a signal generated in the light-receiving section 120.

[0018] Then, the reset transistor 160 is turned on to reset the potential of the capacitor 170, and both the reset transistor 160 and the storage transistor 180 are turned off to prepare for the next signal detection.

[0019] One type of optical sensor is a linear array optical sensor, which uses a light-receiving element with multiple pixels arranged in a one-dimensional array. Linear array optical sensors are often used when capturing a scene while the optical sensor itself moves or when capturing a scene by changing the field of view by swinging a mirror. Linear array optical sensors obtain a continuous image by sequentially reading out signals generated by incident light, such as infrared light, in accordance with the sensor's movement speed or the mirror's scanning speed. Linear array optical sensors may also employ a time delay integration (TDI) method, in which multiple rows of linearly arranged pixel groups are arranged in the direction of the field of view, and the pixel groups in each row integrate signals capturing the same location, albeit with a time delay between them. Linear array optical sensors employing TDI can capture images of a scene with a higher signal-to-noise ratio (S / N) than those without TDI.

[0020] Here, an example of the configuration of a linear array type optical sensor will be described. 3A and 3B are diagrams illustrating examples of the configuration of an optical sensor. FIG. 3A is a schematic plan view of a main part of a first example of the optical sensor. FIG. 3B is a schematic plan view of a main part of a second example of the optical sensor. FIG. 3C is a schematic plan view of a main part of a third example of the optical sensor.

[0021] As described above, a linear array optical sensor includes a light receiving element in which a group of pixels is arranged in a one-dimensional manner. In order to obtain a high-definition image, for example, a linear array optical sensor may use a light receiving element in which a large number of pixels are arranged in a one-dimensional manner.

[0022] The optical sensor 200A shown in FIG. 3A includes a light receiving element 100A and a circuit board 190A. In order to obtain a high-definition image, the light receiving element 100A has a configuration in which a large number of pixels 110 (FIG. 1A) as described above are linearly arranged in a first direction D1. The circuit board 190A has a signal readout circuit 150 (FIG. 2) as described above formed thereon. The light receiving element 100A is mounted on the circuit board 190A by flip chip bonding (FCB) or the like.

[0023] In such an optical sensor 200A, a large number of pixels 110 are linearly arranged in a first direction D1 in a plan view, resulting in a significantly long photodiode 100A in the first direction D1. Even if the photodiode 100A employs a TDI method, the rows of the linearly arranged pixels 110 are only aligned in a second direction D2 perpendicular to the first direction D1 in a plan view, corresponding to the number of TDI rows. Therefore, the length of the photodiode 100A in the second direction D2 is significantly shorter than the length in the first direction D1, resulting in an extremely elongated shape, as shown in FIG. 3A. When the photodiode 100A has an elongated shape, the circuit board 190A on which it is mounted, i.e., the circuit board 190A on which the signal readout circuit 150 is formed, may also have a relatively elongated shape, as shown in FIG. 3A.

[0024] The light receiving element 100A and the circuit board 190A are manufactured through pattern formation using an exposure process. For example, pattern formation using an exposure process is used to form the pixels 110 of the light receiving element 100A and the signal readout circuit 150 of the circuit board 190A.

[0025] However, in order to achieve higher resolution, the number of pixels 110 arranged in the first direction D1 of the light receiving element 100A is increased, and the length in the first direction D1 may be as long as 70 mm. The extremely elongated shapes of the light receiving element 100A and the circuit board 190A may exceed the range of sizes that can be manufactured using a normal exposure apparatus. In this case, the formation area of ​​the light receiving element 100A is divided into multiple parts, or the formation area of ​​the circuit board 190A is divided into multiple parts, and the entire pattern is formed by stitching exposure. However, such stitching exposure may result in an increase in the number of steps and misalignment between patterns (exposure shots).

[0026] Even if the light receiving element 100A and the circuit board 190A can be properly formed using stitched exposure, another problem may arise. That is, if the light receiving element 100A has an extremely elongated shape, when it is mounted on the circuit board 190A using an FCB or the like, the light receiving element 100A may tilt due to uneven contact caused by insufficient parallelism. The tilt of the light receiving element 100A may cause poor connection with the circuit board 190A or tilt of the light receiving surface.

[0027] Misalignment between patterns in stitched exposure, tilt of the light receiving element 100A, poor connection with the circuit board 190A, etc. may make it difficult to perform high-precision optical sensing of a scene using the optical sensor 200A.

[0028] In response to this, it is possible to adopt a configuration such as that shown in FIG. 3(B) or FIG. 3(C) for the linear array type optical sensor. 3B includes a plurality of light receiving elements, here divided into two, for example, a light receiving element 100Ba and a light receiving element 100Bb. The light sensor 200B is obtained by dividing the extremely elongated light receiving element 100A (FIG. 3A) of the light sensor 200A into two, i.e., the two light receiving elements 100Ba and 100Bb realize the same function as the single light receiving element 100A.

[0029] The divided light receiving element 100Ba and the divided light receiving element 100Bb of the optical sensor 200B each have a configuration in which a plurality of pixels 110 (FIG. 1(A)) as described above are linearly arranged in the first direction D1. The divided light receiving element 100Ba and the divided light receiving element 100Bb are both mounted by FCB or the like on a relatively large single circuit board 190B on which the signal readout circuit 150 (FIG. 2) is formed.

[0030] In such an optical sensor 200B, the divided light receiving elements 100Ba and 100Bb are mounted on one circuit board 190B, so that the relative alignment accuracy of the light receiving elements 100Ba and 100Bb is relatively high.

[0031] However, in optical sensor 200B, light receiving elements 100Ba and 100Bb still have an elongated shape, and when mounted on circuit board 190B, light receiving elements 100Ba and 100Bb may tilt due to uneven contact caused by insufficient parallelism. The tilt of light receiving elements 100Ba and 100Bb may cause poor connection with circuit board 190B or tilt of the light receiving surface.

[0032] The tilt of the light receiving elements 100Ba and 100Bb, poor connection with the circuit board 190B, and the like may make it difficult to perform high-precision optical sensing of a scene using the optical sensor 200B.

[0033] 3(C) is an example in which two divided light receiving elements 100Ca and 100Cb are mounted on circuit boards 190Ca and 190Cb, respectively, on which signal readout circuit 150 (FIG. 2) is formed, using FCB or the like. Optical sensor 200C is obtained by dividing the extremely slender light receiving element 100A (FIG. 3(A)) of optical sensor 200A into two, i.e., two light receiving elements 100Ca and 100Cb realize the same function as the single light receiving element 100A.

[0034] The optical sensor 200C is formed by combining a module in which a light receiving element 100Ca is mounted on a circuit board 190Ca and a module in which a light receiving element 100Cb is mounted on a circuit board 190Cb, which are further mounted on a predetermined support (not shown) by adhesive or the like.

[0035] The module in which the light receiving element 100Ca is mounted on the circuit board 190Ca and the module in which the light receiving element 100Cb is mounted on the circuit board 190Cb can be inspected individually to determine whether they are good products. Then, the modules determined to be good products can be combined to obtain the optical sensor 200C. Therefore, an improvement in yield can be expected for the optical sensor 200C.

[0036] However, in optical sensor 200C, light receiving element 100Ca and light receiving element 100Cb still have an elongated shape, and when mounted on circuit board 190Ca and circuit board 190Cb, respectively, they may tilt due to uneven contact caused by insufficient parallelism. The tilt of light receiving element 100Ca and light receiving element 100Cb may result in poor connection with circuit board 190Ca and circuit board 190Cb or tilt of the light receiving surface. Furthermore, in optical sensor 200C, when a module in which light receiving element 100Ca is mounted on circuit board 190Ca and a module in which light receiving element 100Cb is mounted on circuit board 190Cb are combined by bonding them to a support, it is necessary to accurately align their relative pixel positions.

[0037] The tilt of the light receiving element 100Ca and the light receiving element 100Cb, the poor connection between the circuit board 190Ca and the circuit board 190Cb, and the misalignment between the modules resulting from the connection may make it difficult to perform high-precision optical sensing of a scene using the optical sensor 200C.

[0038] As described above, in a linear array optical sensor using a light receiving element in which a plurality of pixels including a light receiving portion are arranged in a one-dimensional array, high-precision implementation of the light receiving element may be difficult due to the configuration of the light receiving element, such as the one-dimensional arrangement of a large number of pixels, the elongated shape when not divided, or the divided shape. If high-precision implementation of the light receiving element cannot be performed, it may be difficult to perform high-precision optical sensing of a scene. Furthermore, if high-precision optical sensing of a scene cannot be performed, it may also be difficult to obtain a high-resolution image of the scene.

[0039] In view of the above, the following configuration is adopted as an embodiment, and a light receiving element capable of performing highly accurate light sensing of a scene and an optical sensor using the same are realized.

[0040] [First embodiment] 4A and 4B are diagrams illustrating an example of an optical sensor according to the first embodiment. Fig. 4A is a schematic plan view of a main part of a first configuration example of the optical sensor according to the first embodiment. Fig. 4B is a schematic plan view of a main part of a second configuration example of the optical sensor according to the first embodiment.

[0041] 4A includes a plurality of light receiving elements 10a and 10b, which are divided into two, as an example. The two light receiving elements 10a and 10b are used to optically sense a target on a line in a scene with a predetermined time difference. The light sensor 1A further includes circuit boards 20a and 20b on which the light receiving elements 10a and 10b are mounted, respectively.

[0042] The light receiving element 10a and the light receiving element 10b each include a plurality of pixels. A signal readout circuit (for example, the signal readout circuit 150 shown in FIG. 2) that reads out signals (charges) from the plurality of pixels included in the light receiving element 10a and the light receiving element 10b is formed on the circuit board 20a and the circuit board 20b, respectively. In the optical sensor 1A, a module 30a in which the light receiving element 10a is mounted on the circuit board 20a and a module 30b in which the light receiving element 10b is mounted on the circuit board 20b are further mounted on a predetermined support (not shown) by adhesive or the like, and combined into one.

[0043] The light receiving element 10a and the light receiving element 10b each include a plurality of blocks in which a plurality of pixels are arranged in a first direction D1 (one-dimensional array), and these blocks are arranged side by side in a second direction D2 perpendicular to the first direction D1. Details of the blocks will be described later. The light receiving element 10a and the light receiving element 10b are configured in such a way that a plurality of blocks in which a plurality of pixels are arranged in the first direction D1 are arranged in the second direction D2, and therefore their size in the second direction D2 is larger than that of an element having only one row of blocks in which a plurality of pixels are arranged in the first direction D1.

[0044] Furthermore, each of the light receiving elements 10a and 10b may be configured such that a plurality of blocks form one unit, and the units are arranged in the second direction D2 in a number equal to the number of stages of the TDI. Details of the blocks and units will be described later. The light receiving elements 10a and 10b are configured in this manner such that a plurality of blocks are arranged in the second direction D2 in a number equal to the number of stages of the TDI, and thus the size in the second direction D2 is larger than that of a light receiving element having a single row of blocks equal to the number of stages of the TDI.

[0045] In this way, the light receiving elements 10a and 10b are each made up of a plurality of blocks or units, each having a fixed length in the first direction D1 corresponding to the number of pixels, arranged side by side in the second direction D2, resulting in a larger planar size than when they are not arranged side by side in the second direction D2. In other words, the light receiving elements 10a and 10b have a planar shape closer to that of a two-dimensional array-type optical sensor. In the example of the optical sensor 1A in FIG. 4(A), the light receiving elements 10a and 10b, which have a relatively large size in the second direction D2, are mounted on the circuit boards 20a and 20b, respectively, using an FCB or the like.

[0046] In the optical sensor 1A, the sizes of the light receiving elements 10a and 10b in the second direction D2 are relatively large, which makes it possible to prevent uneven contact due to insufficient parallelism when mounting the light receiving elements 10a and 10b on the circuit boards 20a and 20b, respectively. This prevents tilting of the light receiving elements 10a and 10b and poor connection with the circuit boards 20a and 20b, enabling highly accurate mounting of the light receiving elements 10a and 10b. Therefore, the optical sensor 1A enables highly accurate optical sensing of a scene using the light receiving elements 10a and 10b.

[0047] Here, two modules 30a and 30b are shown as examples in which two divided light receiving elements 10a and 10b are mounted on circuit boards 20a and 20b, respectively, but the number of modules is not limited to two.

[0048] 4B includes a module 30c in which the light receiving elements 10a and 10b described above are mounted on a single circuit board 20c. The light sensor 1B differs from the light sensor 1A shown in FIG. 4A in this respect. The circuit board 20c is provided with a signal readout circuit (for example, the signal readout circuit 150 shown in FIG. 2) that reads out signals (charges) from the plurality of pixels included in the light receiving elements 10a and 10b. In the light sensor 1B, the light receiving elements 10a and 10b are mounted on the circuit board 20c using an FCB or the like.

[0049] In the optical sensor 1B, the sizes of the light receiving elements 10a and 10b in the second direction D2 are relatively large. This makes it possible to prevent uneven contact due to insufficient parallelism when mounting them on the circuit board 20c. This prevents tilting of the light receiving elements 10a and 10b and poor connection with the circuit board 20c, enabling highly accurate mounting of the light receiving elements 10a and 10b. Furthermore, it makes it possible to position the light receiving elements 10a and 10b on the circuit board 20c with relatively high positional accuracy. Therefore, the optical sensor 1B enables highly accurate optical sensing of a scene using the light receiving elements 10a and 10b.

[0050] Here, we will explain an example of a module 30c in which two divided light receiving elements 10a and 10b are mounted on a single circuit board 20c, but the number of light receiving elements mounted on the circuit board 20c is not limited to two.

[0051] The light receiving elements 10a and 10b and the modules 30a, 30b, and 30c using them will now be described in further detail. In the following description, each of the light receiving elements 10a and 10b will also be referred to as a "light receiving element 10." Each of the circuit boards 20a, 20b, and 20c will also be referred to as a "circuit board 20." Each of the modules 30a, 30b, and 30c will also be referred to as a "module 30."

[0052] Fig. 5 is a diagram illustrating an example of a light receiving element according to the first embodiment. Fig. 5 is a schematic plan view of a main part of an example of a light receiving element according to the first embodiment. As shown in FIG. 5, the light receiving element 10 includes x blocks 11 (x is an integer greater than or equal to 2). Each of the x blocks 11 has a plurality of pixels 12 arranged in a first direction D1 in a planar view. The pixels 12 in each block 11 are arranged in the first direction at a pixel pitch P1 in a planar view. The x blocks 11 are arranged side by side in a second direction D2 perpendicular to the first direction D1 in a planar view, and are shifted from each other in the first direction D1 by a distance (P1 / x) that is 1 / x of the pixel pitch P1. The x blocks 11 are arranged side by side in the second direction D2 at an interval (P1 / x) that is 1 / x of the pixel pitch P1 in a planar view. The pixel pitch P1 is also referred to as a "first pixel pitch."

[0053] The light receiving element 10 having such a configuration is mounted on a circuit board 20 on which a signal readout circuit is formed, thereby realizing a module 30. Fig. 6 is a diagram illustrating a first configuration example of the module according to the first embodiment. Fig. 6(A) and Fig. 6(B) each show a schematic cross-sectional view of a main part of the first configuration example of the module according to the first embodiment.

[0054] Here, Fig. 6(A) is a schematic diagram showing an example of a cross section of a module 30 in which the light receiving element 10 of Fig. 5 is mounted on a circuit board 20, the cross section being taken along line VIa-VIa in Fig. 5 for the light receiving element 10. Fig. 6(B) is a schematic diagram showing an example of a cross section of a module 30 in which the light receiving element 10 of Fig. 5 is mounted on a circuit board 20, the cross section being taken along line VIb-VIb in Fig. 5 for the light receiving element 10.

[0055] As shown in FIGS. 6A and 6B, the light-receiving element 10 includes an etching stopper layer 13, a common electrode 14, an extraction electrode 14a, a light-receiving portion 15, individual electrodes 16, and an insulating film 17. The common electrode 14 is provided on one side of the etching stopper layer 13. A plurality of light-receiving portions 15 are provided at intervals on the side of the common electrode 14 opposite the etching stopper layer 13 side. An individual electrode 16 is provided on the side of each light-receiving portion 15 opposite the common electrode 14 side. Each light-receiving portion 15 is covered with an insulating film 17 except for the connection portion with the individual electrode 16. The common electrode 14 is extracted to the same side as the individual electrode 16 by the extraction electrode 14a.

[0056] Each light receiving section 15 is formed with a light absorbing layer or the like that is sensitive to light such as infrared light. Each pixel 12 of the light receiving element 10 includes such a light receiving section 15. For example, adjacent light receiving sections 15 are separated by pixel separation grooves 18. Each light receiving section 15 has a pixel size S1. As shown in FIG. 6(A), in each block 11, multiple pixels 12 each including a light receiving section 15 are arranged at a pixel pitch P1 in a first direction D1. As shown in FIG. 6(B), each block 11 has a width of the pixel pitch P1, and adjacent blocks 11 are arranged side by side in a second direction D2 with a distance P1 / x between them.

[0057] The circuit board 20 on which the light receiving element 10 described above is mounted includes a substrate 21, a common electrode 22, individual electrodes 23, and an insulating film 24. A signal readout circuit is formed on the substrate 21. Although not shown here, the substrate 21 includes a semiconductor layer made of silicon (Si) or the like on which various transistors and the like included in the signal readout circuit are formed, and a wiring layer including wiring and the like connected to the various transistors and the like. The common electrode 22 and the individual electrodes 23 are provided on one side of the substrate 21 and are exposed from the insulating film 24. The common electrode 22 and the individual electrodes 23 are electrically connected to the various transistors, wiring and the like provided on the substrate 21.

[0058] The common electrode 22 of the circuit board 20 is provided at a position corresponding to the lead-out electrode 14a of the light receiving element 10. The individual electrodes 23 of the circuit board 20 are provided at a position corresponding to the individual electrodes 16 of the light receiving element 10. The common electrode 22 of the circuit board 20 and the lead-out electrode 14a of the light receiving element 10 are connected using connection electrodes 40 such as bumps. Corresponding individual electrodes 23 of the circuit board 20 and individual electrodes 16 of the light receiving element 10 are also connected using connection electrodes 40 such as bumps. This results in a state in which the multiple pixels 12 of the light receiving element 10 are electrically connected to the circuit board 20.

[0059] For example, the light receiving element 10 shown in Fig. 5 has a cross-sectional structure as shown in Fig. 6(A) and Fig. 6(B). For example, such a light receiving element 10 is mounted on a circuit board 20 by an FCB using connection electrodes 40, thereby realizing a module 30 having a configuration as shown in Fig. 6(A) and Fig. 6(B).

[0060] The configuration of the module 30 is not limited to that shown in FIGS. 6(A) and 6(B). 7A and 7B are diagrams illustrating a second configuration example of the module according to the first embodiment. Figures 7A and 7B are schematic cross-sectional views of the main part of the second configuration example of the module according to the first embodiment.

[0061] 7(A) and 7(B) are other examples of the cross-sectional structures shown in FIGS. 6(A) and 6(B), respectively. It can be said that FIG. 7(A) is a schematic representation of another example of a cross section of a module 30 in which the light-receiving element 10 of FIG. 5 is mounted on a circuit board 20, the cross section being taken along line VIa-VIa in FIG. 5 for the light-receiving element 10. It can also be said that FIG. 7(B) is a schematic representation of another example of a cross section of a module 30 in which the light-receiving element 10 of FIG. 5 is mounted on a circuit board 20, the cross section being taken along line VIb-VIb in FIG. 5 for the light-receiving element 10.

[0062] The light receiving element 10 does not necessarily need to be separated into each light receiving section 15 by the pixel separation grooves 18 as described above. The light receiving element 10 may have light receiving sections 15 that are continuous in the first direction D1 and the second direction D2, as shown in Figures 7(A) and 7(B).

[0063] In the light receiving element 10 shown in FIGS. 7(A) and 7(B), pixels 12 having a pixel size S1 are provided in a light receiving section 15 having a continuous shape. In the light receiving element 10 shown in FIGS. 7(A) and 7(B), the pixel size S1 of each pixel 12 is the pixel pitch P1. As shown in FIG. 7(A), in each block 11, the multiple pixels 12 are arranged at the pixel pitch P1 (pixel size S1) in the first direction D1. As shown in FIG. 7(B), each block 11 has a width of the pixel pitch P1 (pixel size S1), and adjacent blocks 11 are arranged side by side in the second direction D2 so that the interval between them is P1 / x.

[0064] 7(A) and 7(B), an extraction electrode 14a extracted from the common electrode 14 of the light receiving element 10 and an individual electrode 16 provided on each pixel 12 are connected to a common electrode 22 and an individual electrode 23 of the circuit board 20 using connection electrodes 40 such as bumps. This results in a state in which the multiple pixels 12 of the light receiving element 10 are electrically connected to the circuit board 20.

[0065] For example, the light receiving element 10 shown in Fig. 5 may have a cross-sectional structure as shown in Fig. 7(A) and Fig. 7(B) in addition to the cross-sectional structure as shown in Fig. 6(A) and Fig. 6(B). For example, such a light receiving element 10 may be mounted on a circuit board 20 by an FCB using connection electrodes 40, thereby realizing a module 30 having a configuration as shown in Fig. 7(A) and Fig. 7(B).

[0066] The module 30 having the above configuration is manufactured, for example, as follows. 8A and 8B are diagrams illustrating an example of a method for manufacturing a module according to the first embodiment. Fig. 8A is a schematic cross-sectional view of a main part of an example of a light-receiving element preparation step according to the first embodiment. Fig. 8B is a schematic cross-sectional view of a main part of an example of a circuit board preparation step according to the first embodiment. Fig. 8C is a schematic cross-sectional view of a main part of an example of an FCB step according to the first embodiment.

[0067] Here, a method for manufacturing a module 30 having the configuration shown in Fig. 6(A) will be described as an example. In manufacturing the module 30, a light receiving element 10 as shown in Fig. 8(A) and a circuit board 20 as shown in Fig. 8(B) are prepared.

[0068] In forming the light-receiving element 10 as shown in FIG. 8A, an etching stopper layer 13, a common electrode 14, and a light-receiving portion 15 are formed on one side of a support substrate 19. The support substrate 19, the etching stopper layer 13, the common electrode 14, and the light-receiving portion 15 are made of compound semiconductors such as InAs, GaSb, and AlSb. The etching stopper layer 13, the common electrode 14, and the light-receiving portion 15 are epitaxially grown in this order on one side of the support substrate 19 using a method such as molecular beam epitaxy (MBE), metal organic chemical vapor deposition (MOCVD), or metal organic vapor phase epitaxy (MOVPE). Next, the light-receiving portion 15 is patterned, and in this example, pixel separation grooves 18 are formed to form a plurality of pixels 12. Next, an insulating film 17 is formed to cover the patterned light-receiving portion 15. The insulating film 17 is made of silicon oxide (SiO) or the like. Next, openings leading to the light receiving sections 15 of each pixel 12 and openings leading to a part of the common electrode 14 are formed in the formed insulating film 17. Then, individual electrodes 16 are formed in the openings leading to the light receiving sections 15, and extraction electrodes 14a are formed in the openings leading to the common electrode 14. Metals such as Ti (titanium), Pt (platinum), and Au are used for the individual electrodes 16 and extraction electrodes 14a. For example, such a method is used to prepare a light receiving element 10 as shown in FIG. 8(A).

[0069] 8(B), a substrate 21 is formed which includes a semiconductor layer of Si or the like on which various transistors and the like included in a signal readout circuit are formed, and a wiring layer including wiring and the like connected to the various transistors and the like. An inorganic or organic insulating film 24 is formed on one side of the substrate 21. A common electrode 22 and individual electrodes 23 are formed so as to be exposed from the insulating film 24 and are electrically connected to the various transistors and wiring and the like of the substrate 21. For example, such a method is used to prepare a circuit substrate 20 including a signal readout circuit as shown in FIG.

[0070] After preparing the light-receiving element 10 and the circuit board 20, the surface of the light-receiving element 10 on which the lead-out electrodes 14a and the individual electrodes 16 are formed is opposed to the surface of the circuit board 20 on which the common electrode 22 and the individual electrodes 23 are formed, as shown in Fig. 8(C). The lead-out electrodes 14a and the common electrode 22, as well as the individual electrodes 16 and the individual electrodes 23 of the light-receiving element 10 and the circuit board 20, are then connected to each other using connection electrodes 40 such as bumps. This completes the basic structure of the module 30, in which the light-receiving element 10 is mounted on the circuit board 20 by FCB using the connection electrodes 40.

[0071] In the module 30, the side of the light receiving element 10 opposite the circuit board 20 is the light receiving surface (incident surface) for light such as infrared light. Therefore, the support substrate 19 on the light receiving surface side may prevent light from reaching the light receiving section 15 of the pixel 12 or may reduce the light reaching efficiency. Therefore, it is desirable to thin or remove the support substrate 19 on the light receiving surface side. Therefore, after the light receiving element 10 is mounted on the circuit board 20, the support substrate 19 of the light receiving element 10 is etched to thin or remove the support substrate 19. For example, by removing the support substrate 19 from the light receiving element 10 after mounting on the circuit board 20, the structure shown in FIG. 6(A) above can be obtained.

[0072] For example, the module 30 is manufactured using the method shown in FIGS. 8(A) to 8(C) and 6(A). Two modules 30, each having a light receiving element 10 mounted on a circuit board 20, are used as the modules 30a and 30b shown in Fig. 4(A) to realize the optical sensor 1A. For example, a module 30 having two light receiving elements 10 mounted on one circuit board 20 is used as the module 30c shown in Fig. 4(B) to realize the optical sensor 1B.

[0073] Here, the light receiving element 10 shown in Fig. 5 is used as the light receiving element 10a of the module 30a and the light receiving element 10b of the module 30b shown in Fig. 4(A). The light receiving element 10 shown in Fig. 5 is used as the light receiving element 10a and the light receiving element 10b of the module 30c shown in Fig. 4(B).

[0074] 5, the light receiving element 10 includes x blocks 11, each of which has a plurality of pixels 12 arranged in a first direction D1 at a pixel pitch P1. As shown in FIG. 5, the light receiving element 10 has x blocks 11 arranged side by side in the second direction D2 and shifted from each other in the first direction D1 by 1 / x of the pixel pitch P1. The light receiving element 10 may be configured such that x blocks 11 form one unit, and the unit is further arranged side by side in the second direction D2 by the number of stages of the TDI.

[0075] In the light receiving element 10, any one of the x blocks 11 is used, and light sensing is performed on a scene moving in the second direction D2 relative to the one block 11. The remaining blocks 11 (x-1 blocks 11) of the x blocks 11 may be configured not to be used for light sensing. If the light receiving element 10 includes units of x blocks 11 equal to the number of stages of the TDI, one block 11 in the unit of each stage may be configured to be used for light sensing, and the remaining blocks 11 in the unit of each stage may be configured not to be used for light sensing.

[0076] The light receiving element 10 has x blocks 11 extending in the first direction D1 arranged side by side in the second direction D2. This arrangement results in a larger size in the second direction D2 than a light receiving element of a conventional linear array optical sensor, in which a single row of blocks 11 is arranged. Furthermore, if the light receiving element 10 includes x blocks 11 units equal to the number of TDI stages, the size in the second direction D2 will be larger than a light receiving element including a single row of blocks 11 equal to the number of TDI stages. In other words, the light receiving element 10 has a planar shape closer to that of a two-dimensional array optical sensor. Therefore, when mounting the light receiving element 10 on the circuit board 20, uneven contact due to insufficient parallelism of the light receiving element 10 can be reduced. This reduces tilt of the light receiving element 10 and poor connection with the circuit board 20, enabling high-precision mounting of the light receiving element 10. Therefore, the use of the light receiving element 10 enables high-precision optical sensing of a scene, enabling high-resolution images of the scene to be acquired.

[0077] In the light receiving element 10, x blocks 11 each extending in the first direction D1 are arranged side by side in the second direction D2 and are shifted from one another in the first direction D1 by 1 / x of the pixel pitch P1. Arranging the x blocks 11 with a shift from one another in the first direction D1 in this manner is effective for aligning the positions of the pixels of, for example, two light receiving elements 10 arranged side by side in the second direction D2 with a partial overlap in the first direction D1 (FIG. 4(A) or FIG. 4(B)).

[0078] That is, from the x number of blocks 11 of each of the two light receiving elements 10, the blocks 11 that result in a combination with the minimum pixel misalignment can be selected, and the blocks 11 of that combination can be used to perform optical sensing of a scene. Using the blocks 11 of the two light receiving elements 10 with the minimum pixel misalignment has the following advantages: A high-resolution image can be obtained when stitching together an image generated based on a signal obtained from one light receiving element 10 and an image generated based on a signal obtained from the other light receiving element 10. For example, it is possible to prevent the boundary between the image generated based on the signal obtained from one light receiving element 10 and the image generated based on the signal obtained from the other light receiving element 10 from becoming unclear or discontinuous, resulting in distortion. That is, it is possible to obtain a seamless image using two light receiving elements 10.

[0079] An example of optical sensing using such a plurality of light receiving elements 10 will be described later (second embodiment). Furthermore, in manufacturing the module 30, after the light receiving element 10 is mounted on the circuit board 20 as shown in Fig. 8(C) above, the support substrate 19 can be removed from the light receiving element 10 by etching. In this case, the light receiving element 10 has a relatively large size in the second direction D2 and a planar shape closer to that of a two-dimensional array type optical sensor, so that the removal accuracy of the support substrate 19 by etching can be improved.

[0080] When the size in the second direction D2 is relatively small, such as in the case of the light receiving elements of a conventional linear array optical sensor in which blocks 11 are arranged in one row or in the same number as the number of stages of the TDI, the removal accuracy of the support substrate 19 by etching may decrease. Possible factors that decrease the removal accuracy of the support substrate 19 by etching include the fact that the light receiving elements have an elongated shape in the first direction D1 and that they may be mounted on the circuit board 20 in an inclined state.

[0081] In contrast, in the case of the light receiving element 10, which has a relatively large size in the second direction D2 and a planar shape closer to that of a two-dimensional array optical sensor, the support substrate 19 can be removed by etching with high precision. This makes it possible to increase the efficiency with which light reaches the light receiving section 15 of the pixel 12. Therefore, it becomes possible to use the light receiving element 10 to perform high-precision sensing of a scene, and to acquire a high-resolution image of the scene.

[0082] Furthermore, since the support substrate 19 is removed by etching with high precision, an improvement in the yield of the module 30 in which the light receiving element 10 is used is expected. For convenience, the term "optical sensor" is used herein to refer to an entity including a module 30 in which a light-receiving element 10 is mounted on a circuit board 20. Alternatively, the light-receiving element 10 may be referred to as an "optical sensor," and the module 30 in which a light-receiving element 10 is mounted on a circuit board 20 may be referred to as an "optical sensor."

[0083] [Second embodiment] Here, an example of the light receiving element 10 described in the first embodiment and an example of a light sensing method using the same will be described as a second embodiment.

[0084] Fig. 9 is a diagram illustrating an example of a light receiving element according to the second embodiment, which is a schematic plan view of a main part of the example of the light receiving element according to the second embodiment. As an example, the light receiving element 10 shown in Fig. 9 includes three blocks 11, i.e., blocks a, b, and c (x=3), as constituent units. For convenience, the blocks a, b, and c are hatched differently in Fig. 9.

[0085] Each of three blocks 11, blocks a, b, and c, in the light receiving element 10 shown in FIG. 9 has a plurality of pixels 12 arranged in a first direction D1 in a plan view. Note that the number of pixels 12 arranged in each block 11 in the first direction D1 is an example and is not limited to the number shown in FIG. 9. The plurality of pixels 12 in each block 11 are arranged in the first direction D1 at a pixel pitch P1 in a plan view. The three blocks 11, blocks a, b, and c, are arranged side by side in a second direction D2 perpendicular to the first direction D1 in a plan view, and are shifted from each other in the first direction D1 by a distance (P1 / 3) that is 1 / 3 of the pixel pitch P1. The blocks 11 are arranged side by side in the second direction D2 at an interval (P1 / 3) that is 1 / 3 of the pixel pitch P1 in a plan view.

[0086] The light receiving element 10 shown in Fig. 9 includes three blocks 11, blocks a, b, and c, which are arranged with a shift of P1 / 3 in each block in the first direction D1, as one unit 11A. The light receiving element 10 shown in Fig. 9 has a configuration in which such units 11A are arranged in the number of stages of the TDI (four stages in this example) and are further arranged side by side in the second direction D2. The units 11A are arranged side by side in the second direction D2 with the positions of the outermost pixels 12 (the pixels 12 on the left or right edge of each block 11) among the multiple pixels 12 in the first direction D1 aligned.

[0087] In the light receiving element 10 shown in FIG. 9, one of the units 11A included in the light receiving element 10 is also referred to as a "first unit," and the other is also referred to as a "second unit."

[0088] For example, the light receiving element 10 shown in Fig. 9 is used as the light receiving element 10a and the light receiving element 10b shown in Fig. 4(A) above, and these are mounted on the circuit board 20a and the circuit board 20b, respectively, to realize the optical sensor 1A shown in Fig. 4(A) above. For example, the light receiving element 10 shown in Fig. 9 is used as the light receiving element 10a and the light receiving element 10b shown in Fig. 4(B) above, and these are mounted on the circuit board 20c to realize the optical sensor 1B shown in Fig. 4(B) above.

[0089] 9, when optical sensing is performed using the light receiving element 10, for example, one block 11 in each stage of the units 11A is used to perform TDI optical sensing. That is, among all the blocks 11, blocks a in each stage of the four stages of the units 11A (four in total) are used to perform TDI optical sensing. Alternatively, among all the blocks 11, blocks b in each stage of the four stages of the units 11A (four in total) are used to perform TDI optical sensing. Alternatively, among all the blocks 11, blocks c in each stage of the four stages of the units 11A (four in total) are used to perform TDI optical sensing.

[0090] 9, the blocks 11 are arranged side by side in the second direction D2 at intervals of P1 / 3, so that, for example, the blocks a of each unit 11A are arranged at intervals of a total of three pixels (the pixel pitch P1 of blocks b and c and the interval of P1 / 3 × 3). Similarly, the blocks b of each unit 11A are arranged at intervals of a total of three pixels, and the blocks c of each unit 11A are arranged at intervals of a total of three pixels. Therefore, in TDI-type optical sensing, the positional relationship between the blocks 11 of each stage used is simplified, the delay timing when reading out signals accumulated in the blocks 11 of each stage is simplified, and control of the signal readout circuit is made easier.

[0091] In the light-receiving element 10 shown in FIG. 9, units 11A including three blocks 11 (a, b, c) extending in the first direction D1 are arranged in four rows, the number of rows of the TDI, in the second direction D2. Therefore, the size of the light-receiving element 10 shown in FIG. 9 is larger in the second direction D2 than a light-receiving element 10 in which a single row of blocks 11 is arranged in four rows, the number of rows of the TDI. In other words, the light-receiving element 10 shown in FIG. 9 has a planar shape closer to that of a two-dimensional array optical sensor. Therefore, when mounting this light-receiving element 10 on a circuit board 20, it is possible to prevent uneven contact due to insufficient parallelism of the light-receiving element 10. This prevents tilting of the light-receiving element 10 and poor connection with the circuit board 20, enabling high-precision mounting of the light-receiving element 10.

[0092] Therefore, by using the light receiving element 10 shown in FIG. 9, it is possible to perform high-precision optical sensing of a scene, and to acquire a high-resolution image of the scene. Furthermore, in the light receiving element 10 shown in FIG. 9, the increased size in the second direction D2 allows for high-precision mounting, and the support substrate 19 (FIG. 8(C)) can be etched with high precision during the manufacturing process. This increases the efficiency with which light reaches the pixel 12, enabling high-precision sensing of a scene, and enabling a high-resolution image of the scene to be acquired. Furthermore, the high-precision etching of the support substrate 19 (FIG. 8(C)) can improve yield.

[0093] Next, an example of an optical sensing method using a plurality of light receiving elements 10 having the configuration shown in FIG. 9 will be described. Fig. 10 is a diagram illustrating an example of the arrangement of light receiving elements according to the second embodiment, which is a schematic plan view of the main part of the example of the arrangement of light receiving elements according to the second embodiment.

[0094] In FIG. 10, for convenience, the three blocks 11, blocks a, b, and c, are hatched differently. For example, a light receiving element 10 having the configuration shown in Fig. 9 above, here as an example two light receiving elements 10a and 10b, are arranged to line up in the second direction D2 as shown in Fig. 10. The two light receiving elements 10a and 10b are arranged to partially overlap each other in the first direction D1 as shown in Fig. 10. It can also be said that the two light receiving elements 10a and 10b are arranged so that the units 11A of each element are arranged to line up in the second direction D2 and partially overlap each other in the first direction D1.

[0095] In the light receiving element 10a and the light receiving element 10b shown in FIG. 10, the unit 11A included in one light receiving element 10a is also referred to as the "first unit," and the unit 11A included in the other light receiving element 10b is also referred to as the "second unit."

[0096] For example, the two light receiving elements 10a and 10b shown in Fig. 10 may be mounted on separate circuit boards 20a and 20b, i.e., may be included in separate modules 30a and 30b, as shown in the example of Fig. 4(A) above. In this case, the circuit board 20a on which one light receiving element 10a is mounted is also referred to as the "first circuit board," and the circuit board 20b on which the other light receiving element 10b is mounted is also referred to as the "second circuit board."

[0097] 10 may be mounted on a single circuit board 20c, i.e., included in a single module 30c, as shown in the example of FIG. 4(B). In this case, the circuit board 20c on which the two light receiving elements 10a and 10b are mounted is also referred to as the "circuit board."

[0098] 10, the light receiving element 10a and the light receiving element 10b are arranged such that an end portion of one light receiving element 10a (a group of several pixels 12 provided at the right end) overlaps an end portion of the other light receiving element 10b (a group of several pixels 12 provided at the left end). Here, when a module 30a including the light receiving element 10a and a module 30b including the light receiving element 10b are mounted on a support by adhesive or the like, misalignment may occur between the modules 30a and 30b, i.e., between the light receiving element 10a and the light receiving element 10b. Alternatively, when the light receiving element 10a and the light receiving element 10b are mounted on a single circuit board 20c to form the module 30c, misalignment may occur between the light receiving element 10a and the light receiving element 10b.

[0099] For example, in a case where a row of blocks 11 are arranged side by side (as in the cases shown in FIGS. 3B and 3C above) as in a conventional linear array optical sensor, misalignment between the blocks 11 can cause a discrepancy in the continuity of the pixels between the blocks 11. Therefore, when an image generated based on signals obtained from one row of blocks 11 and an image generated based on signals obtained from another row of blocks 11 are stitched together with a delay corresponding to the distance between the blocks 11, the following may occur: The boundary between the two images in the stitched image may become unclear or discontinuous, causing distortion in the stitched image and making it impossible to obtain a seamless, high-definition image.

[0100] 10, if the light receiving elements 10a and 10b are arranged so as to overlap, it is possible to suppress discontinuity of the pixels 12 caused by misalignment between the light receiving elements 10a and 10b. That is, the misalignment between the pixels 12 in one of the blocks 11 a, b, and c in one light receiving element 10a and the pixels 12 in one of the blocks 11 a, b, and c in the other light receiving element 10b is suppressed to a small value.

[0101] In the specific example shown in Fig. 10, the positional deviation between pixels 12 in block a in one light receiving element 10a and pixels 12 in block b in the other light receiving element 10b is smaller than the positional deviation between pixels 12 in the remaining blocks a and c, resulting in the smallest positional deviation. Therefore, in the example of Fig. 10, block a of each unit 11A in one light receiving element 10a is used for light sensing, and block b of each unit 11A in the other light receiving element 10b is used for light sensing.

[0102] That is, the blocks a in each stage of the four-stage unit 11A of the light receiving element 10a are used to perform optical sensing by TDI of a scene moving in the second direction D2 relative to the group of blocks a. Also, the blocks b in each stage of the four-stage unit 11A of the light receiving element 10b are used to perform optical sensing by TDI of a scene moving in the second direction D2 relative to the group of blocks b. The delay timing is controlled based on the positional relationship between the group of blocks a of the light receiving element 10a and the group of blocks b of the light receiving element 10b. The signals accumulated in the group of blocks a and the group of blocks b by optical sensing are used to generate an image of the scene.

[0103] Here, the block group a of the light receiving element 10a and the block group b of the light receiving element 10b are combined to minimize the positional deviation of the pixels 12 relative to each other. Therefore, when an image generated based on the signal obtained from the light receiving element 10a and an image generated based on the signal obtained from the light receiving element 10b are stitched together, a seamless, high-resolution stitched image can be obtained. For example, it is possible to prevent the boundary between the image generated based on the signal obtained from the light receiving element 10a and the image generated based on the signal obtained from the light receiving element 10b from becoming unclear or discontinuous, resulting in distortion. This enables high-precision optical sensing of a scene and acquisition of a high-resolution image of the scene.

[0104] The light receiving element 10a may be configured such that block a, which has a relatively small positional deviation from the pixels 12 of the light receiving element 10b, is used for light sensing, and the remaining blocks b and c, which have a relatively large positional deviation from the pixels 12 of the light receiving element 10b, are not used for light sensing. The light receiving element 10b may be configured such that block b, which has a relatively small positional deviation from the pixels 12 of the light receiving element 10a, is used for light sensing, and the remaining blocks a and c, which have a relatively large positional deviation from the pixels 12 of the light receiving element 10a, are not used for light sensing.

[0105] Which of blocks a, b, and c of light receiving element 10a is used and which of blocks a, b, and c of light receiving element 10b is used can be determined by using a measurement technique such as 3D measurement of their positions after light receiving element 10a and light receiving element 10b are arranged. For example, as shown in the example of FIG. 4A above, modules 30a and 30b, in which light receiving element 10a and light receiving element 10b are mounted on circuit boards 20a and 20b, respectively, are further mounted on a support by adhesive or the like, and then 3D measurement or the like is performed. Alternatively, as shown in the example of FIG. 4B above, 3D measurement or the like is performed on module 30c, in which light receiving element 10a and light receiving element 10b are mounted on circuit board 20c.

[0106] For example, a reference point (such as a corner of the chip or a separately formed mark) is set on the light receiving element 10a, and the position of at least one pixel 12 from that reference point is determined. A reference point is also set on the circuit board 20a. The positions of the reference points of the light receiving element 10a and the circuit board 20a are measured by 3D measurement or the like, and the positions of the pixels 12 of the light receiving element 10a mounted on the circuit board 20a can be determined based on the relative positions of the measured reference points. Similarly, the positions of the pixels 12 of the light receiving element 10b mounted on the circuit board 20b can be determined. After mounting on the support, the positions of the pixels 12 of the light receiving elements 10a and 10b mounted on the circuit board 20a can be determined from the relative positions of the circuit boards 20a and 20b on the support. The positions of the pixels 12 of the light receiving elements 10a and 10b mounted on the circuit board 20c can also be determined by 3D measurement or the like of those reference points.

[0107] The positional relationship between the groups of pixels 12 in the light receiving elements 10a and 10b is known from the pixel pitch P1 and the above-described configuration (arrangement rule). Therefore, once the position of at least one pixel 12 after arrangement (mounting) is determined, the positions of all groups of pixels 12 and the positions of the blocks 11 can be determined. Based on the position information thus determined, it is possible to determine a combination of blocks 11 (block a of the light receiving elements 10a and block b of the light receiving elements 10b in the above example) that minimizes the positional deviation of the pixels 12 between the light receiving elements 10a and 10b after arrangement. Furthermore, based on the position information thus determined, it is possible to determine the relative distance between the blocks 11 in the combination that minimizes the positional deviation of the pixels 12. Based on this relative distance, it is possible to control the delay timing between the light receiving elements 10a and 10b.

[0108] 11 and 12 are diagrams illustrating an example of an optical sensing method using a light receiving element according to the second embodiment. 11 and 12, for the sake of convenience, the three blocks 11, blocks a, b, and c, are hatched differently.

[0109] Fig. 11 is a schematic diagram showing the arrangement of the blocks 11 of the light receiving element 10a and the light receiving element 10b. In Fig. 11, four rows of units 11A of the light receiving element 10a, each of which includes three blocks 11 (a, b, c), and four rows of units 11A of the light receiving element 10b, each of which includes three blocks 11 (a, b, c), are arranged in a straight line in the second direction D2. Fig. 11 is an image diagram showing the light receiving element 10a and the light receiving element 10b shown in Fig. 10, as viewed from the side (the right or left side of the paper surface of Fig. 10).

[0110] The scene moves in the second direction D2 relative to the optical sensor including such light receiving elements 10a and 10b, and therefore the optical sensor moves relatively in the opposite direction (the direction of the thick arrow in FIG. 11).

[0111] 10, the combination of the block a group of the light receiving element 10a and the block b group of the light receiving element 10b is assumed to minimize the positional deviation of the pixels 12. In the light receiving element 10a, the blocks a (referred to herein as "blocks a1, a2, a3, and a4") of the four rows of units 11A among all the blocks 11 are used for light sensing. In the light receiving element 10b, the blocks b (referred to herein as "blocks b1, b2, b3, and b4") of the four rows of units 11A among all the blocks 11 are used for light sensing.

[0112] An example of how optical sensing is performed in the arrangement shown in Fig. 11 is shown in Fig. 12. Fig. 12 is a schematic diagram showing how a scene in which background 51, target 50, and background 52 are arranged in the movement direction of the optical sensor is focused on the optical sensor through an optical system. Consider the case in which light receiving elements 10a and 10b arranged as shown in Fig. 11 move relatively in the movement direction of the optical sensor with respect to background 51, target 50, and background 52 of the scene.

[0113] In the example of Figure 12, at time T02, light such as infrared light from background 51 is incident on pixel 12 of block a3 of light receiving element 10a. At time T03, the optical sensor moves, and light from target 50 is incident on pixel 12 of block a3. At time T04, the optical sensor moves, and light from background 52 is incident on pixel 12 of block a3.

[0114] As the optical sensor continues to move, at time T06, light from background 51 is incident on pixel 12 of block a4 of light receiving element 10a. Then, at time T07, light from target 50 is incident on pixel 12 of block a4, and at time T08, light from background 52 is incident on pixel 12 of block a4.

[0115] As the optical sensor moves further, at time T16, light from background 51 is incident on pixel 12 of block b1 of light receiving element 10b. Then, at time T17, light from target 50 is incident on pixel 12 of block b1, and at time T18, light from background 52 is incident on pixel 12 of block b1.

[0116] For example, the signal generated and accumulated in block a3 by the incidence of light at time T03, the signal generated and accumulated in block a4 by the incidence of light at time T07, and the signal generated and accumulated in block b1 by the incidence of light at time T17 are integrated, thereby obtaining a high S / N image of the target 50 in the scene.

[0117] Although the focus here is on blocks a3, a4, and b1 for convenience, light from the target 50 in the scene may also be incident on other blocks a1, a2, b2, b3, and b4 as the optical sensor moves. When acquiring an image, the signals generated and accumulated in blocks a1, a2, a3, and a4 may be integrated, or the signals generated and accumulated in blocks b1, b2, b3, and b4 may be integrated.

[0118] For convenience, the example shown here illustrates an example in which an image is acquired by integrating signals generated by blocks a3, a4, b1, etc. of the light receiving element 10a and the light receiving element 10b for the same target 50 in the scene. Alternatively, if the target of the scene differs between the light receiving element 10a and the light receiving element 10b, the images acquired from each are stitched together. That is, an image generated based on signals generated and integrated by the block a group of the light receiving element 10a and an image generated based on signals generated and integrated by the block b group of the light receiving element 10b are stitched together with a delay based on the relative positions of the block a group and the block b group. The block a group of the light receiving element 10a and the block b group of the light receiving element 10b are combined to minimize the misalignment of the pixels 12 between them. This minimizes distortion at the boundary of the stitched images, enabling a high-resolution image of the scene to be acquired.

[0119] In the above description of the second embodiment, a case where one unit 11A of the light receiving element 10 includes three blocks 11 (x=3) has been described as an example, but the number of blocks 11 included in one unit 11A is not limited to this. Increasing the number of blocks 11 included in one unit 11A of the light receiving element 10 increases the size of the light receiving element 10 in the second direction D2, thereby reducing tilt and connection failure and achieving high-precision mounting. Furthermore, increasing the number of blocks 11 included in one unit 11A of the light receiving element 10 makes it easier to combine blocks 11 with small pixel 12 misalignment between different light receiving elements 10. Alternatively, it becomes easier to minimize pixel 12 misalignment between combined blocks 11. This makes it possible to improve the S / N ratio of images generated based on signals obtained from different light receiving elements 10 and reduce distortion at the boundaries of stitched images. As a result, it becomes possible to acquire higher-resolution images.

[0120] Furthermore, in the explanation of Figures 10 to 12 in the second embodiment, an example using two light receiving elements 10 as shown in Figure 9 was described, but it is also possible to perform optical sensing by arranging three or more light receiving elements 10 as shown in Figure 9 so that they overlap each other.

[0121] The light receiving element 10 having the configuration shown in FIG. 9 can also be called an "optical sensor," and the module 30 in which the light receiving element 10 is mounted on the circuit board 20 can also be called an "optical sensor."

[0122] [Third embodiment] Fig. 13 is a diagram illustrating an example of a light receiving element according to the third embodiment, which diagrammatically shows a plan view of a main part of an example of a light receiving element according to the third embodiment.

[0123] 13 includes three blocks 11, a, b, and c (x=3), as constituent units. For convenience, blocks a, b, and c are hatched differently in FIG.

[0124] Each of three blocks 11, blocks a, b, and c, in the light receiving element 10 shown in Fig. 13 has a plurality of pixels 12 arranged in a matrix in a first direction D1 and a second direction D2 in a plan view. Note that the number of pixels 12 arranged in the first direction D1 in each block 11 is an example and is not limited to the number shown in Fig. 13. Also, as an example, each block 11 has four rows of pixels 12, which is the number of rows of TDI, arranged in the second direction D2, but the number of pixels 12 arranged in the second direction D2 is not limited to this.

[0125] 13, the pixels 12 included in each of the blocks 11, a, b, and c, are arranged at a pixel pitch P1 in a first direction D1 and a second direction D2 in a plan view. The three blocks 11, a, b, and c, are arranged side by side in a second direction D2 that is perpendicular to the first direction D1 in a plan view, and are shifted from each other in the first direction D1 by a distance of 1 / 3 (P1 / 3) of the pixel pitch P1.

[0126] 13 includes three blocks 11, blocks a, b, and c, which are arranged with a shift of P1 / 3 in the first direction D1, as one unit 11A. The light receiving element 10 may further include a plurality of such units 11A. In this case, one of the group of units 11A will be referred to as the "first unit" and the other as the "second unit."

[0127] The light receiving element 10 shown in FIG. 13 differs from the light receiving element 10 (FIG. 9) described in the second embodiment in that it has such a configuration. 13 can be said to be a combination of the block a group, the block b group, and the block c group of the four-stage unit 11A shown in FIG. 9 of the second embodiment, all combined into a single block 11. The light receiving element 10 having the configuration shown in FIG. 13 also makes it possible to perform highly accurate optical sensing of a scene, and to obtain a high-resolution image of the scene.

[0128] 13, light sensing is performed using, for example, one of blocks 11 a, b, or c of one or more units 11A. Signals accumulated by the pixel 12 groups of each row are integrated by TDI using four rows of pixel 12 groups (columns) in the block 11, and an image is generated based on the integrated signals. This allows a high-resolution image of the scene to be acquired.

[0129] For example, the light receiving element 10 shown in Fig. 13 is used as the light receiving element 10a and the light receiving element 10b shown in Fig. 4(A) above, and these are mounted on the circuit board 20a and the circuit board 20b, respectively, to realize the optical sensor 1A shown in Fig. 4(A) above. For example, the light receiving element 10 shown in Fig. 13 is used as the light receiving element 10a and the light receiving element 10b shown in Fig. 4(B) above, and these are mounted on the circuit board 20c to realize the optical sensor 1B shown in Fig. 4(B) above.

[0130] In this case, two light receiving elements 10 having the configuration shown in Fig. 13 are arranged side by side in the second direction D2 and partially overlapping in the first direction D1, following the example of Fig. 10 above. Then, the blocks 11 (groups of pixels 12 arranged in a matrix) of one light receiving element 10 and the other light receiving element 10 that result in a combination with minimal positional deviation of the pixels 12 are used, and light sensing is performed according to the example described in the second embodiment above. In this case, the unit 11A including the block 11 used for light sensing of one light receiving element 10 is also referred to as the "first unit," and the unit 11A including the block 11 used for light sensing of the other light receiving element 10 is also referred to as the "second unit."

[0131] For example, signals accumulated by four rows of pixels 12 in a block 11 used for light sensing of one light receiving element 10 and signals accumulated by four rows of pixels 12 in a block 11 used for light sensing of the other light receiving element 10 are integrated. An image is generated based on the signals integrated in this manner. This allows a high-resolution image of the scene to be acquired.

[0132] Alternatively, an image is generated based on signals accumulated and integrated by four rows of pixels 12 in a block 11 used for light sensing of one of the light receiving elements 10. An image is generated based on signals accumulated and integrated by four rows of pixels 12 in a block 11 used for light sensing of the other light receiving element 10. These two images are then stitched together. This allows a high-resolution image of the scene to be obtained.

[0133] In the above description of the third embodiment, a case where one unit 11A of the light receiving element 10 includes three blocks 11 (x=3) has been described as an example, but the number of blocks 11 included in one unit 11A is not limited to this. Increasing the number of blocks 11 included in one unit 11A of the light receiving element 10 increases the size of the light receiving element 10 in the second direction D2, thereby reducing tilt and connection failure and achieving high-precision mounting. Furthermore, increasing the number of blocks 11 included in one unit 11A of the light receiving element 10 makes it easier to combine blocks 11 with small pixel 12 misalignment between different light receiving elements 10. Alternatively, it becomes easier to minimize pixel 12 misalignment between combined blocks 11. This makes it possible to improve the S / N ratio of images generated based on signals obtained from different light receiving elements 10 and reduce distortion at the boundaries of stitched images. As a result, it becomes possible to acquire higher-resolution images.

[0134] Furthermore, in the explanation of the third embodiment above, an example was described in which one or two light receiving elements 10 as shown in FIG. 13 are used, but it is also possible to perform optical sensing by arranging three or more light receiving elements 10 as shown in FIG. 13 so that they overlap each other.

[0135] The light receiving element 10 having the configuration shown in FIG. 13 can also be called an "optical sensor," and the module 30 in which the light receiving element 10 is mounted on the circuit board 20 can also be called an "optical sensor."

[0136] [Fourth embodiment] Here, an example of an electronic device equipped with a light sensor will be described as the fourth embodiment. FIG. 14 is a diagram illustrating an example of an electronic device according to the fourth embodiment.

[0137] 14 includes an imaging unit 61, a processing unit 62, a storage unit 63, and a display unit 64. The imaging unit 61 includes an optical sensor 1 that uses a module 30 in which a light receiving element 10 is mounted on a circuit board 20 as described in the first to third embodiments. The optical sensor 1 or the imaging unit 61 that includes the optical sensor 1 may be housed in a cooler 65.

[0138] The processing unit 62 controls the operation of the optical sensor 1 of the imaging unit 61. For example, the processing unit 62 controls circuit elements such as transistors of the signal readout circuit and applies bias to the pixels 12 of the light receiving element 10. The processing unit 62 further generates an image of light incident on the optical sensor 1 using a signal detected by the optical sensor 1 of the imaging unit 61. The memory unit 63 stores the image generated by the processing unit 62. The display unit 64 displays the image generated by the processing unit 62 or an image generated by the processing unit 62 and stored in the memory unit 63.

[0139] The processing unit 62 is, for example, a processor such as a CPU (Central Processing Unit), a GPU (Graphics Processing Unit), or a DSP (Digital Signal Processor). The processing unit 62 may include an application-specific electronic circuit such as an ASIC (Application Specific Integrated Circuit) or an FPGA (Field Programmable Gate Array). The processing unit 62 executes a program stored in a memory (which may be the storage unit 63) such as a RAM (Random Access Memory). The storage unit 63 may be a volatile semiconductor memory such as a RAM, or a non-volatile storage such as a HDD (Hard Disk Drive) or a flash memory. The display unit 64 is, for example, a display device.

[0140] In the electronic device 60, the processing unit 62 controls the operation of the optical sensor 1 of the imaging unit 61. In the electronic device 60, the processing unit 62 controls the operation of the optical sensor 1 of the imaging unit 61, and detects signals of light incident on the pixels 12 of the optical sensor 1. In the electronic device 60, the processing unit 62 uses the signals detected by the optical sensor 1 to generate an image. In the electronic device 60, the image generated by the processing unit 62 is displayed on the display unit 64. In the electronic device 60, for example, an image of a scene through the optical sensor 1 is acquired by such processing by the processing unit 62.

[0141] The light receiving element 10 described in the first to third embodiments is used in the optical sensor 1 of such an electronic device 60. As described above, the light receiving element 10 enables highly accurate sensing of a scene, making it possible to acquire a high-resolution image of the scene. By using the light receiving element 10 in the optical sensor 1, a high-performance electronic device 60 is realized.

[0142] The following additional notes are provided regarding the above-described embodiment. (Supplementary Note 1) The image sensor includes x blocks (x is an integer of 2 or more), each of which has a plurality of pixels arranged in a first direction in a planar view; the plurality of pixels are arranged at a first pixel pitch in the first direction in a plan view, An optical sensor in which the x blocks are arranged side by side in a second direction perpendicular to the first direction in a planar view and are shifted from each other in the first direction by a distance of 1 / x of the first pixel pitch.

[0143] (Supplementary Note 2) The optical sensor according to Supplementary Note 1, wherein the x blocks are arranged side by side in the second direction at intervals of 1 / x of the first pixel pitch in a plan view. (Supplementary Note 3) The optical sensor according to Supplementary Note 1, wherein the x blocks each have the plurality of pixels arranged in a matrix in the first direction and the second direction in a plan view.

[0144] (Supplementary Note 4) A first unit and a second unit each having the x number of blocks, An optical sensor as described in Appendix 1, wherein the first unit and the second unit are arranged side by side in the second direction in a planar view, with the positions of the outermost pixels of each of the plurality of pixels in the first direction aligned.

[0145] (Supplementary Note 5) The optical sensor according to Supplementary Note 4, including a circuit board on which the first unit and the second unit are mounted and which is electrically connected to the plurality of pixels included in the first unit and the second unit.

[0146] (Supplementary Note 6) A first unit and a second unit each having the x number of blocks, An optical sensor as described in Appendix 1, wherein the first unit and the second unit are arranged side by side in the second direction in a planar view and are arranged so as to partially overlap each other in the first direction.

[0147] (Supplementary Note 7) A first circuit board on which the first unit is mounted and which is electrically connected to the plurality of pixels included in the first unit; a second circuit board on which the second unit is mounted and which is electrically connected to the plurality of pixels included in the second unit; 7. The optical sensor of claim 6, comprising:

[0148] (Supplementary Note 8) The optical sensor according to Supplementary Note 6, including a circuit board on which the first unit and the second unit are mounted and which is electrically connected to the plurality of pixels included in the first unit and the second unit.

[0149] (Supplementary Note 9) The image sensor includes x blocks (x is an integer equal to or greater than 1) each having a plurality of pixels arranged in a first direction in a planar view, the plurality of pixels are arranged at a first pixel pitch in the first direction in a plan view, an optical sensing method using an optical sensor, wherein the x blocks are arranged side by side in a second direction perpendicular to the first direction in a plan view and are shifted from each other in the first direction by a distance of 1 / x of the first pixel pitch, An optical sensing method using one of the x blocks to sense light from a scene moving in the second direction relative to the one block.

[0150] (Supplementary Note 10) The optical sensor a first unit and a second unit each having the x blocks; the first unit and the second unit are arranged side by side in the second direction in a plan view such that positions of outermost pixels among the plurality of pixels in the first direction are aligned, and An optical sensing method as described in Appendix 9, in which light from a scene moving in the second direction relative to each other's blocks is sensed using blocks among the x blocks in each of the first unit and the second unit in which the positions of the multiple pixels are aligned.

[0151] (Appendix 11) The optical sensing method described in Appendix 10, wherein the optical sensor integrates and reads out an optical signal sensed in one of the blocks and an optical signal sensed in the other of the blocks with a timing shift corresponding to the distance from the one block.

[0152] (Supplementary Note 12) The optical sensor a first unit and a second unit each having the x blocks; the first unit and the second unit are arranged side by side in the second direction in a plan view and are arranged to partially overlap each other in the first direction, An optical sensing method as described in Appendix 9, wherein light from a scene moving in the second direction relative to each other's blocks is sensed using blocks from each of the x blocks in the first unit and the second unit that form a combination with the smallest positional shift of the multiple pixels in the first direction.

[0153] (Appendix 13) The optical sensing method described in Appendix 12, wherein the optical sensor reads out a signal of light sensed in one of the blocks, and reads out a signal of light sensed in the other of the blocks with a timing shift corresponding to the distance from the one block.

[0154] (Supplementary Note 14) The image sensor includes x blocks (x is an integer equal to or greater than 1) each having a plurality of pixels arranged in a first direction in a planar view, the plurality of pixels are arranged at a first pixel pitch in the first direction in a plan view, The x blocks are arranged side by side in a second direction perpendicular to the first direction in a planar view, and are provided with optical sensors that are shifted from each other in the first direction by a distance of 1 / x of the first pixel pitch. [Explanation of symbols]

[0155] 1, 1A, 1B, 200, 200A, 200B, 200C Optical Sensor 10, 10a, 10b, 100, 100A, 100Ba, 100Bb, 100Ca, 100Cb photodetector 11, a, a1, a2, a3, a4, b, b1, b2, b3, b4, c block 11A unit 12,110 pixels 13 Etching stop layer 14, 22 common electrode 14a Extraction electrode 15, 120 Light receiving section 16, 23 Individual electrodes 17, 24 Insulating film 18, 111 Pixel separation groove 19 Support substrate 20, 20a, 20b, 20c, 190A, 190B, 190Ca, 190Cb circuit board 21 PCB 30, 30a, 30b, 30c modules 40 connecting electrode 50 goals 51, 52 Background 60 Electronic equipment 61 Imaging unit 62 Processing section 63 Memory section 64 Display section 65 Cooler 121 Light absorbing layer 122 Hole barrier layer 130 1st electrode 140 2nd electrode 150 Signal readout circuit 151 Potential detection circuit 160 Reset transistor 170 capacity 180 Storage transistor D1 1st direction D2 2nd direction S1 pixel size P1 pixel pitch T01-T19 hours V0 potential Vrst Reset Level

Claims

1. includes x blocks (x is an integer of 2 or more) each having a plurality of pixels arranged in a first direction in a planar view, the plurality of pixels are arranged at a first pixel pitch in the first direction in a plan view, An optical sensor in which the x blocks are arranged side by side in a second direction perpendicular to the first direction in a planar view, and are shifted from each other in the first direction by a distance of 1 / x of the first pixel pitch.

2. The optical sensor according to claim 1 , wherein the x blocks are arranged side by side in the second direction at intervals of 1 / x of the first pixel pitch in a plan view.

3. The optical sensor according to claim 1 , wherein each of the x blocks has the plurality of pixels arranged in a matrix in the first direction and the second direction in a plan view.

4. a first unit and a second unit each having the x blocks; 2. The optical sensor according to claim 1, wherein the first unit and the second unit are arranged side by side in the second direction in a plan view, with the positions of the outermost pixels of the plurality of pixels in the first direction aligned.

5. a first unit and a second unit each having the x blocks; The optical sensor according to claim 1 , wherein the first unit and the second unit are arranged side by side in the second direction in a plan view and are arranged so as to partially overlap each other in the first direction.

6. includes x blocks (x is an integer of 2 or more) each having a plurality of pixels arranged in a first direction in a planar view, the plurality of pixels are arranged at a first pixel pitch in the first direction in a plan view, an optical sensing method using an optical sensor, wherein the x blocks are arranged side by side in a second direction perpendicular to the first direction in a plan view and are shifted from each other in the first direction by a distance of 1 / x of the first pixel pitch, A light sensing method using one of the x blocks to sense light from a scene moving in the second direction relative to the one block.

7. The optical sensor a first unit and a second unit each having the x blocks; the first unit and the second unit are arranged side by side in the second direction in a plan view such that positions of outermost pixels of the plurality of pixels in the first direction are aligned, The optical sensing method of claim 6, wherein light from a scene moving in the second direction relative to each other is sensed using blocks among the x number of blocks in each of the first unit and the second unit in which the positions of the plurality of pixels are aligned.

8. The optical sensor a first unit and a second unit each having the x blocks; the first unit and the second unit are arranged side by side in the second direction in a plan view and are arranged to partially overlap each other in the first direction, 7. The optical sensing method of claim 6, wherein light from a scene moving in the second direction relative to each other's blocks is sensed using a combination of the x blocks in each of the first unit and the second unit that results in the smallest positional shift of the multiple pixels in the first direction.

9. includes x blocks (x is an integer of 2 or more) each having a plurality of pixels arranged in a first direction in a planar view, the plurality of pixels are arranged at a first pixel pitch in the first direction in a plan view, The x blocks are arranged side by side in a second direction perpendicular to the first direction in a planar view, and are provided with optical sensors that are shifted from each other in the first direction by a distance of 1 / x of the first pixel pitch.

Images