Light detection device and wafer

Abstract

This technology relates to a photodetector and a thin sheet that can limit the influence on photodetection while preventing dirt from adhering to the photodetector. The imaging device includes an imaging unit and signal processing circuitry as a photodetector element that detects incident light. The imaging device also includes a lens for controlling the light incident on the photodetector element and a surface portion formed on the light-incident side of the photodetector element. The surface portion is formed by a plurality of protrusions regularly arranged on a plate that transmits light. For example, this technology can be applied to imaging devices that include a CMOS image sensor or other imaging element, a lens, and a surface portion and capture images of an object.

Description

Technical Field

[0001] This technology relates to optical detection devices and wafers, and more particularly to optical detection devices and wafers capable of suppressing the effects on optical detection while preventing dirt from adhering to the optical detection device. Background Technology

[0002] As a result of the proliferation of automation and the Internet of Things (IoT) using artificial intelligence (AI), the use of stand-alone light detection devices, which are light detection devices not directly involved by humans, is increasing. Examples of stand-alone light detection devices include security cameras, unmanned imaging cameras (such as cameras used in AI checkout devices in cash registers, parking lots, etc.), and sensors for unmanned mobile devices (unmanned mobility) (such as drones or automated vehicles).

[0003] On the other hand, in optical detection devices, the presence of dirt can prevent detection, leading to false detections or decreased detection accuracy. Therefore, removing dirt from optical detection devices is crucial. In optical detection devices that involve direct human contact, people can identify dirt and remove it through cleaning or other methods.

[0004] However, dirt adhering to stand-alone photodetectors cannot be identified and removed by humans. Therefore, stand-alone photodetectors need to have the function of detecting the dirt themselves and removing it through cleaning or other means, or to perform regular cleaning and other maintenance on the stand-alone photodetectors.

[0005] As a method for removing dirt in a self-standing optical detection device, for example, a method for removing dirt from a vehicle-mounted camera using a cleaning fluid is designed (see, for example, Patent Document 1 and Patent Document 2).

[0006] However, the above methods require significant costs to remove dirt, such as power consumption due to the cleaning fluid spraying mechanism, the task of filling the cleaning fluid, mounting the cleaning fluid nozzle near the vehicle camera, or incorporating various components into the spraying mechanism.

[0007] Reference List

[0008] Patent documents

[0009] Patent Document 1: PCT enters the Japanese national phase, patent publication number 2022-547672

[0010] Patent Document 2: Japanese Patent Application Publication No. 2022-131226 Summary of the Invention

[0011] The problem to be solved by the present invention

[0012] As mentioned above, it is difficult to remove the dirt adhering to the optical detection device in a stand-alone unit. In addition, in places such as at sea, there are situations where dirt that is difficult to remove during cleaning or maintenance operations adheres to the optical detection device, making it difficult for the device to perform long-term or continuous detection.

[0013] Therefore, there is a need for a technology that can suppress the effects of light detection and prevent dirt from adhering to the light detection device, but this need has not been adequately met.

[0014] The present invention was made in view of the above circumstances, and its purpose is to prevent dirt from adhering to the photodetector while suppressing the influence of photodetection.

[0015] Solution to the problem

[0016] The light detection device in the first aspect of this technology is a light detection device comprising: a light detection element for detecting incident light; a light control unit for controlling the light incident on the light detection element; and a surface portion formed on the incident side of the light relative to the light detection element, wherein the surface portion includes a plurality of protrusions regularly arranged on a plate for transmitting light.

[0017] The first aspect of this technology includes a light detection element for detecting incident light, a light control unit for controlling the light incident on the light detection element, and a surface portion formed on the incident side of the light relative to the light detection element, wherein the surface portion includes a plurality of protrusions regularly arranged on a plate for transmitting light.

[0018] The second aspect of this technology is a sheet for a light detection device, wherein the light detection device includes: a light detection element for detecting incident light; and a light control unit for controlling the light incident on the light detection element. The sheet is formed on the incident side of the light relative to the light detection element, and the sheet includes a plurality of protrusions regularly arranged on a plate for transmitting light.

[0019] In a second aspect of the present technology, the light detection device includes: a light detection element for detecting incident light; and a light control unit for controlling the light incident on the light detection element. The second aspect of the present technology is formed on the light incident side relative to the light detection element and includes a plurality of protrusions regularly arranged on a plate that transmits light. Attached Figure Description

[0020] Figure 1 This is a diagram illustrating an example configuration of an imaging apparatus used as a light detection device applying the present technology according to a first embodiment.

[0021] Figure 2 This is a top view showing a first structural example of the surface portion.

[0022] Figure 3It is shown Figure 2 A side view of an example of a protruding structure.

[0023] Figure 4 This is a diagram illustrating the relationship between the contact angle of a droplet and its hydrophilicity or hydrophobicity.

[0024] Figure 5 This is a side view showing a second structural example of the surface portion.

[0025] Figure 6 This is a top view showing a third structural example of the surface portion.

[0026] Figure 7 These are top and side views showing a fourth structural example of the surface portion.

[0027] Figure 8 These are top and side views showing a fifth structural example of the surface portion.

[0028] Figure 9 This is a top view showing an example of the protruding configuration.

[0029] Figure 10 This is a top view showing the sixth structural example of the surface portion.

[0030] Figure 11 This is a diagram illustrating an example configuration of an imaging apparatus according to a second embodiment of a light detection device to which this technology is applied.

[0031] Figure 12 This is a diagram showing an example of the structure of a mask.

[0032] Figure 13 This is a block diagram illustrating an example of a schematic configuration of a vehicle control system.

[0033] Figure 14 This is an explanatory diagram showing an example of the mounting position of the imaging unit. Detailed Implementation

[0034] The modes for implementing this technology (hereinafter referred to as implementation methods) will be described below. Note that they will be described in the following order.

[0035] 1. First embodiment (imaging device including lens)

[0036] 2. Second embodiment (imaging device excluding lens)

[0037] 3. Examples of applications of moving bodies

[0038] Furthermore, in the accompanying drawings referenced in the following description, the same or similar reference numerals are used to denote the same or similar parts. However, the drawings are schematic, and the relationships between thicknesses and planar dimensions, the thickness ratios of each layer, etc., differ from reality. In addition, the drawings may include parts with different dimensional relationships or ratios in some cases.

[0039] Furthermore, the definitions of directions such as up and down in the following description are merely for ease of description and do not limit the technical concept of this disclosure. For example, if the target is rotated 90° and observed, up and down are interpreted by replacing them with left and right, and if the target is rotated 180° and observed, up and down are interpreted by reversing them.

[0040] <1. First Implementation Method>

[0041] <Imaging Device Configuration Example>

[0042] Figure 1 This is a diagram illustrating an example configuration of an imaging apparatus used as a light detection device applying the present technology according to a first embodiment.

[0043] Figure 1 The imaging device 10 shown is a camera, which includes, from the light incident side, a surface portion 11, a lens 12, an imaging unit 13, and a signal processing circuit 14. The imaging device 10 images the object 20 and generates a captured image.

[0044] Specifically, the surface portion 11 is formed on the boundary surface between the imaging device 10 and the external world. The surface portion 11 includes a plurality of protrusions regularly arranged on a flat plate that transmits light from the object 20. Examples of materials for the surface portion 11 include transparent resins, such as polyvinyl chloride (PVC), polypropylene (PP), polycarbonate (PC) or polystyrene (PS), siloxane-based inorganic coatings (glass coatings), etc. The materials of the flat plate and the protrusions of the surface portion 11 may be the same or different.

[0045] Lens 12 is a light control unit that controls the light incident from object 20 through surface portion 11 onto imaging unit 13.

[0046] The imaging unit 13 and the signal processing circuit 14 constitute an imaging element (light detection element) such as a CMOS (Complementary Metal-Oxide-Semiconductor) image sensor that detects light incident through the lens 12. Specifically, the imaging unit 13 receives light incident through the lens 12 and generates an electrical signal corresponding to the amount of light received as optical information. The imaging unit 13 provides the electrical signal to the signal processing circuit 14. The signal processing circuit 14 performs predetermined signal processing based on the electrical signal supplied from the imaging unit 13 to generate an image.

[0047] Alternatively, the surface portion 11 and the lens 12 can be integrated. In other words, the surface portion 11 can be formed on the incident side surface of the lens 12. The surface portion 11 can be constructed in a form different from a sheet or the like of the lens 12, and can be attached to the incident side surface of the lens 12.

[0048] <First Structural Example of the Surface Part>

[0049] Figure 2 It shows Figure 1 Top view of the first structural instance of surface portion 11.

[0050] exist Figure 2 In the surface portion 11, multiple protrusions 32 with light-shielding properties are arranged at equal intervals in a two-dimensional grid shape (matrix shape) on a plate 31 with light-transmitting properties. Figure 2 In the example, the protrusion 32 is conical in shape, and the diameter of the circle at the base of the protrusion 32 is 10 μm. The spacing between the protrusions 32 in the horizontal direction (row direction) and the spacing in the vertical direction (column direction) are 25 μm.

[0051] <First structural example of a protrusion>

[0052] Figure 3 It shows Figure 2 A side view of a structural example of protrusion 32.

[0053] As mentioned above, Figure 2 The protrusion 32 is conical in shape, and therefore the side surface of the protrusion 32 is triangular in shape, such as... Figure 3 As shown. The generatrix of protrusion 32 is approximately the same as the diameter of the circle on the bottom surface of protrusion 32. The plate 31 has light-transmitting properties, but protrusion 32 has light-blocking properties, for example, by applying a black light-blocking film to the surface.

[0054] Therefore, light incident on the surface portion 11, for example, light incident on the region 31a formed by the surface of the protrusion 32 on the side not subject to light incidence by the plate 31, passes through the plate 31 and is incident on the imaging unit 13 through the lens 12. On the other hand, light incident on the protrusion 32 is absorbed by the protrusion 32 and is not refracted or reflected by the protrusion 32. Therefore, light incident on the protrusion 32 does not pass through the lens 12 and is incident on the imaging unit 13, and does not adversely affect the captured image.

[0055] Note that the black light-blocking film may be applied only to the bottom surface of protrusion 32.

[0056] <Explanation of the relationship between contact angle and hydrophilicity or hydrophobicity>

[0057] Figure 4It is a diagram illustrating the relationship between the contact angle of a droplet attached to a solid surface and its hydrophilicity or hydrophobicity.

[0058] like Figure 4 As shown, as the contact angle θ decreases, hydrophilicity increases and hydrophobicity decreases. The contact angle θ is the angle formed by the flat surface of the solid surface 52 to which the droplet 51 adheres (e.g., a water droplet) and the contour of the droplet 51, located at the intersection of the flat surface of the solid surface 52 and the contour curve of the droplet 51. As the contact angle θ increases, hydrophilicity decreases and hydrophobicity increases. Hydrophilicity is the property of wetting a droplet, while hydrophobicity is the property of repelling a droplet. Generally, a contact angle θ of 100 degrees or more is called hydrophobicity, and a contact angle θ of 150 degrees or more is called superhydrophobicity.

[0059] Here, when the surface tension of droplet 51 is the same as the surface tension of droplet 51 in complete close contact with solid surface 52, if solid surface 52 is a rough surface, droplet 51 is subjected to amplified surface tension due to protrusions contained in the rough surface. In other words, the protrusions cause an increase in the contact angle θ. Therefore, the contact angle θr when solid surface 52 is a rough surface can be represented by the effective contact area ratio r (r≥1) according to the following approximation (1). The effective contact area ratio r is the ratio of the surface area of ​​solid surface 52 to the floor area when solid surface 52 is a rough surface, which is the surface area of ​​solid surface 52 when solid surface 52 is a flat surface. In other words, the effective contact area ratio r represents the roughness of solid surface 52.

[0060] [Mathematical Expression 1]

[0061] In equation (1), θ1 represents the contact angle of droplet 51 when the solid surface 52 is a flat surface. The above approximation (1) is called the Wenzel equation. According to equation (1), the contact angle θr increases with the increase of the effective contact area ratio r. Therefore, maximizing the water repellency is maximizing the effective contact area ratio r.

[0062] Therefore, to maximize the water repellency of surface portion 11, maximizing the effective contact area ratio r of surface portion 11 is sufficient. S It is expressed by the following formula (2).

[0063] [Mathematical Expression 2]

[0064] In equation (2), a is the radius of the bottom surface of protrusion 32, b (b>a) is the length of the generatrix of protrusion 32, and c (2a<c) is the interval (spacing) between protrusions 32 in the horizontal and vertical directions, that is, the interval between the centers of the corresponding protrusions 32 in the horizontal and vertical directions.

[0065] As shown in equation (2), the effective contact area ratio r S The surface area c of the flat plate 31 with a protrusion 32 is... 2 The sum of the areas πab of the side surfaces of the protrusion 32 minus the area πa of the base surface 2 The area obtained is relative to the surface area c. 2 than.

[0066] According to equation (2), the effective contact area ratio r S It is expressed by the quadratic form of a, the linear form of b, and the quadratic form of the reciprocal of c. According to equation (2), as the length b of the generatrix of protrusion 32 increases, and as the width 2a of protrusion 32 becomes closer to the interval c, the effective contact area ratio r S Increase. Therefore, by making the angle of the apex of the cone of the protrusion 32 more acute and making the spacing c between the protrusions 32 closer to the width 2a of the protrusion 32, the water repellency of the surface portion 11 can be improved. As a result, water droplets and other liquids adhering to the surface portion 11 retain dirt adhering to the surface portion 11 and flow down from the surface portion 11.

[0067] However, if the protrusion 32 is too small than the droplet, the droplet cannot make complete and tight contact with the surface of the protrusion 32 due to the surface tension of the droplet, and the surface area in contact with the droplet does not increase. Therefore, the minimum size of the protrusion 32 is set to be larger than the minimum size of the droplet. For example, the minimum size of a water droplet, determined based on the surface tension at atmospheric pressure, is approximately 1.3 μm. Therefore, the minimum size of the protrusion 32 is set to be between 0.1 μm and 1 μm at atmospheric pressure.

[0068] On the other hand, if the protrusion 32 is too large compared to the water droplet, the protrusion 32 does not function as a rough surface relative to the water droplet, but rather as a flat surface. Therefore, the maximum size of the protrusion 32 is set such that the protrusion 32 functions as a rough surface relative to the water droplet.

[0069] In view of the above, the protrusion 32 is formed, for example, in such a way that the height and width of the protrusion 32, more specifically, the size of the generatrix b and the diameter 2a of the base are approximately the same (e.g., one is 10 times smaller than the other), and are a few μm to tens of μm under atmospheric pressure. With the height and width of the protrusion 32 being approximately the same, it is easy to manufacture the protrusion 32.

[0070] As described above, to improve water repellency, it is preferable that the spacing between the protrusions 32 is small. However, the protrusions 32 block light, and therefore, if the spacing between the protrusions 32 is too small, sufficient light for imaging will not be incident on the imaging portion 13. The amount of light sufficient for imaging varies depending on the performance of the imaging element. Therefore, the spacing between the protrusions 32 is set in a manner that allows sufficient light for imaging to be incident on the imaging portion 13, depending on the performance of the imaging element, the bottom region of the protrusions 32, etc. As described above, the linear light transmittance and water repellency of the surface portion 11 are in a trade-off.

[0071] <Second structural example of the surface portion>

[0072] Figure 5 This is a side view showing a second structural example of surface portion 11.

[0073] exist Figure 5 In the surface portion 11, with Figure 3 The portions corresponding to those portions of surface portion 11 are denoted by the same reference numerals. Therefore, the description of these portions is appropriately omitted, and the focus will be on the portions corresponding to those of surface portion 11. Figure 3 The differences in the surface portion 11 are described. Figure 5 Surface portion 11 and Figure 3 The difference in surface portion 11 is that a black light-blocking film is not applied to the protrusion 32, and on the side of lens 12 ( Figure 5 A black light-shielding portion 71 is formed in the region corresponding to the region 70 on the light-incident side of the plate 31 (on the lower side). Figure 5 The surface portion 11 is constructed similarly to Figure 3 Surface portion 11.

[0074] In other words, in Figure 5 In the surface portion 11, the region 31a of the plate 31 where the protrusion 32 is not formed has light-transmitting properties, and the light-shielding portion 71 corresponding to the region 70 where the protrusion 32 is formed has light-shielding properties. The size of the region of the light-shielding portion 71 is slightly larger than the size of the bottom surface of the protrusion 32. Light incident on the protrusion 32 is absorbed by the light-shielding portion 71 and is neither transmitted through the light-shielding portion 71 nor reflected by the light-shielding portion 71. Therefore, the light incident on the protrusion 32 does not pass through the lens 12 and is incident on the imaging portion 13.

[0075] It should be noted that when the protrusion 32 is shaped like a cone or a triangular pyramid with refractive index or reflective properties, light that does not pass through the protrusion 32 is incident on the imaging unit 13 through the lens 12. Therefore, it is not necessary to apply a light-shielding film to the protrusion 32 or to place the light-shielding part 71 in the plate 31.

[0076] The light-shielding portion 71 may be formed in the region corresponding to region 70 on the light-incident side of the plate 31. Instead of forming the light-shielding portion 71, a light-shielding film may be applied to the region corresponding to region 70 on the surface of one side of the lens 12 of the plate 31.

[0077]

[0078] Figure 6 This is a top view (bird's-eye view) showing a third structural example of surface portion 11.

[0079] It should be noted that, Figure 6 To simplify the accompanying drawings, only a portion of the surface portion 11 is shown.

[0080] exist Figure 6 In the surface portion 11, with Figure 3 The portions corresponding to those portions of surface portion 11 are denoted by the same reference numerals. Therefore, the description of these portions is appropriately omitted, and the focus will be on the portions corresponding to those of surface portion 11. Figure 3 The differences in the surface portion 11 are described. Figure 6 Surface portion 11 and Figure 3 The surface portion 11 differs in that it includes protrusions 81 in the shape of a regular triangular pyramid, instead of protrusions 32 in the shape of a cone, and in other respects... Figure 6 Surface portion 11 is configured to be with Figure 3 The surface portion 11 is similar.

[0081] exist Figure 6 In the instance of A, the interval between the protrusions 81 in the horizontal and vertical directions is the length of one side of the equilateral triangle on the base of protrusion 81. Figure 6 In the instance of B, the length of one side of the equilateral triangle on the base of protrusion 81 is Figure 6 The length of one side of the equilateral triangle of instance A is 1 / 3, and the spacing of protrusion 81 in the horizontal and vertical directions is twice the length of one side of the equilateral triangle of the base of protrusion 81.

[0082] exist Figure 6 In the surface portion 11 of A, Figure 6 The ratio of the area of ​​region 31a of plate 31 without protrusion 81 to the area of ​​the entire surface on the light incident side of plate 31 is less than Figure 6 The ratio in the surface portion 11 of B. Therefore, Figure 6 The surface portion 11 of A has a greater than Figure 6 The surface portion 11 of B has a lower linear transmittance. However, compared with... Figure 6 Compared to the case of surface portion 11 of B, in Figure 6The spacing between the protrusions 81 in the surface portion 11 of A is close to the width of the protrusion 81, that is, the diameter of the inscribed circle of the bottom surface of the protrusion 81, thus resulting in high water repellency.

[0083] on the contrary, Figure 6 Surface portion 11 of B and Figure 6 The surface portion 11 of A has higher linear light transmittance but lower water repellency compared to its counterpart. However, by increasing... Figure 6 The height of the B-shaped protrusion 81 can improve water repellency.

[0084] <Fourth structural example of the surface portion>

[0085] Figure 7 These are top and side views showing a fourth structural example of surface portion 11. Specifically, Figure 7 A and Figure 7 B are the top view and side view of the fourth structural example of surface portion 11, respectively.

[0086] exist Figure 7 In the surface portion 11, corresponding to Figure 3 Those parts of surface portion 11 are denoted by the same reference numerals. Therefore, the description of these parts is appropriately omitted, and the focus will be on those parts with... Figure 3 The differences in the surface portion 11 are described. Figure 7 Surface portion 11 and Figure 3 The difference in surface portion 11 is that three protrusions 91 are formed on the side surface of protrusion 32, and in other respects, Figure 7 Surface portion 11 and Figure 3 The surface portion 11 is constructed similarly.

[0087] like Figure 7 As shown in A and B, the three protrusions 91 formed on the side surface of protrusion 32 are all cones of the same size. In other words, the entire shape of protrusions 32 and 91 on surface portion 11 is fractal. The size of protrusion 91 is smaller than that of protrusion 32, and... Figure 7 In this example, it is half the size of protrusion 32. The length of the generatrix of the base of protrusion 91 is approximately the same as the diameter of the circle. Figure 7 In the example, the corresponding vertices of the three protrusions 91 exist concentrically and at equal intervals on the same plane perpendicular to the line perpendicular from the vertex of protrusion 32.

[0088] As described above, by forming a protrusion 91 smaller than the protrusion 32 on the side surface of the protrusion 32, even droplets that are too small relative to the protrusion 32 are droplets of an appropriate size relative to the protrusion 91, and the protrusion 91 can serve as a rough surface relative to the droplet. As a result, the water repellency of the surface portion 11 for droplets of different sizes is improved. Furthermore, with... Figure 3 Compared to the surface portion 11, the formation of protrusions 91 leads to an increase in the effective contact area of ​​the surface portion 11, thus improving the water repellency itself.

[0089] <Fifth structural example of the surface portion>

[0090] Figure 8 These are top and side views showing a fifth structural example of surface portion 11. Specifically, Figure 8 A and Figure 8 B are the top view and side view of the fifth structural example showing the surface portion 11, respectively.

[0091] exist Figure 8 In the surface portion 11, corresponding to Figure 6 Those parts of surface portion 11 are denoted by the same reference numerals. Therefore, the description of these parts is appropriately omitted, and the focus will be on those parts with... Figure 6 The differences in the surface portion 11 are described. Figure 8 Surface portion 11 and Figure 6 The difference in surface portion 11 is that three protrusions 111 are formed on the side surface of protrusion 81, and in other respects, Figure 8 Surface portion 11 is configured to be with Figure 6 The surface portion 11 is similar.

[0092] like Figure 8 As shown in A and B, the three protrusions 111 formed on the side surface of protrusion 81 are all regular triangular pyramids of the same size. That is, the overall shape of protrusions 81 and 111 on surface portion 11 is fractal. The size of protrusion 111 is smaller than that of protrusion 81, and... Figure 8 In this example, the size of protrusion 81 is half that of the other protrusion. Three protrusions 111 are formed on the three corresponding triangular side surfaces of protrusion 81 in the same manner in the height direction perpendicular to the plate 31.

[0093] As described above, by forming protrusions 111 smaller than protrusion 81 on the side surface of protrusion 81, even droplets that are too small relative to protrusion 81 have a suitable size relative to protrusion 111, and protrusion 111 can serve as a rough surface relative to the droplet. Therefore, the water repellency of droplets with different sizes is improved. Furthermore, with... Figure 6Compared to the surface portion 11, the formation of protrusions 111 leads to an increase in the effective contact area of ​​the surface portion 11, thus improving the water repellency itself.

[0094] <Example of raised arrangement>

[0095] Figure 9 It shows Figure 8 A top view of an example of the arrangement of protrusions 81 in surface portion 11.

[0096] It should be noted that Figure 9 Only the area of ​​surface portion 11 in which 2×2 protrusions 81 are disposed is shown to simplify the figures. This also applies to the descriptions that follow. Figure 10 .

[0097] The spacing between the protrusions 81 is set such that a protrusion 111 disposed on the side of a protrusion 81 does not contact a protrusion 111 disposed on the side of an adjacent protrusion 81. Figure 9 In the example, the spacing between the protrusions 81 in the horizontal and vertical directions is twice the length of one side of the equilateral triangle on the base of the protrusion 81.

[0098] Note that, as Figures 7 to 9 As shown, when protrusion 91 (111) is formed on the side surface of protrusion 32 (81), the linear transmittance of surface portion 11 depends significantly on the size of the bottom surface of protrusion 32 (81) and the spacing between protrusions 32 (81) in the horizontal and vertical directions.

[0099] The number of divisions of the size of protrusion 32 (81) is not limited to two. The size of protrusion 32 (81) is divided, for example, in such a way that the smallest size is the size that allows protrusion 32 (81) to be used as a rough surface relative to the assumed droplet. Therefore, in the case where the protrusion with the largest size is an extremely slender cube or the like, the number of divisions of the size of the protrusion increases.

[0100] <Sixth structural example of the surface portion>

[0101] Figure 10 This is a top view showing a sixth structural example of surface portion 11.

[0102] exist Figure 10 In the surface portion 11, corresponding to Figure 9 Those parts of surface portion 11 are denoted by the same reference numerals. Therefore, the description of these parts is appropriately omitted, and the focus will be on those parts with... Figure 9 The differences in the surface portion 11 are described. Figure 10 Surface portion 11 and Figure 9 The difference in surface portion 11 is that new protrusions 131 are formed, and in other respects, Figure 10 Surface portion 11 and Figure 9 The surface portion 11 is constructed similarly.

[0103] like Figure 10 As shown, protrusion 131 is a regular triangular pyramid with the same dimensions as protrusion 111. Figure 10 In this example, for every 2×2 protrusions 81, a protrusion 131 is positioned at the center of the 2×2 protrusions 81. Furthermore, the protrusions 131 can be arbitrarily arranged as long as they are positioned between the protrusions 81. By forming protrusions 131 identical to those 111, the number of protrusions 111 and 131 with sizes suitable for small droplets increases. Therefore, the water repellency of the surface portion 11 can be further improved.

[0104] As described above, the imaging device 10 includes a surface portion 11, a lens 12, an imaging unit 13, and a signal processing circuit 14, and the surface portion 11 includes a plurality of protrusions 32 (81) regularly arranged on a light-transmitting plate 31. Therefore, water repellency is improved, while linear light transmission characteristics are achieved in the region 31a of the surface portion 11 where no protrusions 32 (81) are formed. As a result, it is possible to prevent dirt from adhering to the imaging device 10 while suppressing its influence on imaging. This allows the imaging device 10 to be installed even in places or conditions where dirt is difficult to remove. To ensure the reliability of the imaging device 10, for example, it is not necessary to detect and remove dirt adhering to the imaging device 10, or even if dirt is adhering, it is not necessary to perform signal processing that produces images with high image quality, thus simplifying the imaging device 10.

[0105] Conversely, when the imaging device performs signal processing to generate high-quality images even when dirt is present, the signal processing becomes complex and the processing load increases. In cases where lenses are coated with water-repellent materials, such as by spraying, to prevent dirt from adhering to the imaging element, the material causes significant changes in the light incident on the lens, making it difficult for the imaging element to receive light properly.

[0106] Furthermore, the shape of the protrusion 32 (81, 91, 111, or 131) can be any shape other than a cone or a regular triangular pyramid, such as a polygonal prism or a pyramid. When the protrusion 32 (81, 91, 111, or 131) is a quadrangular prism, the surface portion 11 can be easily manufactured. The protrusion 91 (111) can be arranged on the plate 31 near the protrusion 32 (81) instead of being formed on the side surface of the protrusion 32 (81). In this case, the surface portion 11 is easy to manufacture.

[0107] The shape, size, and spacing of the protrusions 32 (81, 91, 111, or 131) are configured according to the performance of the imaging unit 13 or the signal processing circuit 14 in subsequent stages. For example, the shape, size, and spacing of the protrusions 32 (81, 91, 111, or 131) are configured such that the surface portion 11 has a linear light transmittance according to the performance of the imaging unit 13 or the signal processing circuit 14, and the water repellency is maximized. In cases where the signal processing circuit 14 can interpolate the reduction in linear light transmittance or insufficient light due to the protrusions 32 (81 or 131), it is sufficient for the surface portion 11 to have a smaller linear light transmittance, and the water repellency can be further improved.

[0108] Considering the effect of light that has passed through the protrusions 32 (81, 91, 111, or 131), it is not necessary to form a light-shielding film (light-shielding part 71) if the signal processing circuit 14 is capable of performing processing, regardless of the shape, size, and spacing of the protrusions 32 (81, 91, 111, or 131). The spacing of the protrusions 32 (81) only needs to be approximately equal, and does not necessarily have to be exactly equal.

[0109] <2. Second Implementation Method>

[0110] <Imaging Device Configuration Example>

[0111] Figure 11 This is a diagram illustrating an example configuration of an imaging apparatus according to a second embodiment of a light detection device to which this technology is applied.

[0112] exist Figure 11 In the imaging device 210, and in Figure 1 The parts corresponding to the parts in the imaging device 10 are indicated by the same reference numerals. Therefore, the description of these parts is appropriately omitted, and the focus will be on the differences from the imaging device 10. The imaging device 210 is a lensless camera, and differs from the imaging device 10 in that it includes a surface portion 211 and a mask 212 instead of a surface portion 11 and a lens 12, and in other respects, the imaging device 210 is configured similarly to the imaging device 10.

[0113] The surface portion 211 differs from the surface portion 11 in that it has protrusions formed at locations other than those corresponding to the multiple holes formed in the mask 212, but otherwise it is configured in the same way as the surface portion 11.

[0114] The mask 212 is a light control unit that controls the light incident from the object 20 onto the imaging unit 13 via the surface portion 211. Specifically, multiple fine holes (random holes) penetrating the mask 212 are formed intermittently on the mask 212. The mask 212 serves as an encoding opening, and light incident from the object 20 is emitted to the imaging unit 13 via the surface portion 211 without focusing the light using the fine holes. Therefore, the captured image generated by the signal processing circuit 14 of the imaging device 10 is a non-formed image. Thus, in a subsequent stage, a formed image is recovered from the captured image using an image processing device (not shown).

[0115] Note that the surface portion 211 and the mask 212 can be integral. In other words, the surface portion 211 can be formed on the incident side surface of the mask 212. The surface portion 211 can be configured in the form of a thin sheet or the like, different from the mask 212, and can be attached to the incident side surface of the mask 212.

[0116] <Example of Mask Structure>

[0117] Figure 12 It shows Figure 11 A diagram illustrating a structural example of mask 212.

[0118] like Figure 12 As shown, a plurality of fine holes 231 are formed aperiodically in the mask 212. Light incident on the mask 212 is emitted to the imaging unit 13 through the fine holes 231. Therefore, no protrusions are formed in the region of the fine holes 231 corresponding to the plate of the surface portion 211. That is, protrusions are formed in the region of the plate of the surface portion 211 corresponding to the light-shielding region other than the fine holes 231 of the mask 212. This prevents the protrusions from adversely affecting the light incident on the imaging unit 13 through the fine holes 231.

[0119] As described above, the imaging device 210 includes a surface portion 211, a mask 212, an imaging unit 13, and a signal processing circuit 14. The surface portion 211 includes a plurality of protrusions disposed in a region other than the region corresponding to the aperture 231 of the mask 212, which is a plate for transmitting light. Therefore, the surface portion 211 can improve water repellency while exhibiting linear light transmission characteristics in the region corresponding to the aperture 231. Thus, it is possible to suppress the influence on imaging while preventing dirt from adhering to the imaging device 210.

[0120] Note that the protrusions can be arranged regularly in the surface portion 211.

[0121] This technology can also be applied to optical detection devices, including those utilizing optical detection elements, in addition to imaging devices that include imaging elements.

[0122] <3. Examples of applications of moving bodies>

[0123] The technology disclosed herein (the Technology) can be applied to various types of products. For example, the Technology disclosed herein can be implemented as a device mounted on any type of mobile body, such as a car, electric vehicle, hybrid electric vehicle, motorcycle, bicycle, personal mobility device, airplane, drone, ship, or robot.

[0124] Figure 13 This is a block diagram illustrating a schematic configuration example of a vehicle control system, which is an example of a mobile body control system to which the technology according to this disclosure can be applied.

[0125] The vehicle control system 12000 includes multiple electronic control units interconnected via a communication network 12001. Figure 13 In the example shown, the vehicle control system 12000 includes a drive system control unit 12010, a body system control unit 12020, an external information detection unit 12030, an internal information detection unit 12040, and an integrated control unit 12050. Furthermore, as examples of the functional structure of the integrated control unit 12050, a microcomputer 12051, an audio / image output unit 12052, and an in-vehicle network interface (I / F) 12053 are shown.

[0126] The drive system control unit 12010 controls the operation of devices related to the vehicle's drive system according to various programs. For example, the drive system control unit 12010 is used as a control device for drive force generating devices (such as internal combustion engines, drive motors, etc.) that generate drive force for the vehicle, drive force transmission mechanisms that transmit drive force to the wheels, steering mechanisms that adjust the vehicle's steering angle, and braking devices that generate braking force for the vehicle.

[0127] The body system control unit 12020 controls the operation of various devices installed on the vehicle body according to various programs. For example, the body system control unit 12020 serves as a control device for keyless entry systems, smart key systems, power windows, or various lights such as headlights, taillights, brake lights, turn signals, fog lights, etc. In this case, radio waves or signals from various switches, which are alternatives to buttons, can be input to the body system control unit 12020. The body system control unit 12020 receives these input radio waves or signals and controls the vehicle's door locks, power windows, lights, etc.

[0128] The exterior information detection unit 12030 detects exterior information, including information from outside the vehicle, which is part of the vehicle control system 12000. For example, an imaging unit 12031 is connected to the exterior information detection unit 12030. The exterior information detection unit 12030 causes the imaging unit 12031 to capture images of the exterior of the vehicle and receives these captured images. Furthermore, the exterior information detection unit 12030 can also perform processing based on the received images, such as detecting people, vehicles, obstacles, signs, text on the road surface, etc., or detecting their distances.

[0129] The imaging unit 12031 is an optical sensor that receives light and outputs an electrical signal corresponding to the amount of light received. The imaging unit 12031 can output an electrical signal as an image, or it can output an electrical signal as information about the measured distance. Furthermore, the light received by the imaging unit 12031 can be visible light, or it can be invisible light such as infrared light.

[0130] The in-vehicle information detection unit 12040 detects information about the interior of the vehicle. The in-vehicle information detection unit 12040 is connected, for example, to a driver state detection unit 12041 that detects the driver's state. The driver state detection unit 12041 includes, for example, a camera that captures images of the driver. Based on the detection information input from the driver state detection unit 12041, the in-vehicle information detection unit 12040 can calculate the driver's fatigue level or concentration level, or determine whether the driver is drowsy.

[0131] The microcomputer 12051 can calculate control target values ​​for the drive force generation device, steering mechanism, or braking device based on information about the vehicle's interior or exterior obtained by the external information detection unit 12030 or the internal information detection unit 12040, and output control commands to the drive system control unit 12010. For example, the microcomputer 12051 can perform cooperative control designed to implement functions of an advanced driver assistance system (ADAS), including collision avoidance or shock absorption for the vehicle, following driving based on following distance, maintaining vehicle speed, collision warning, lane departure warning, etc.

[0132] In addition, the microcomputer 12051 controls the drive force generating device, steering mechanism, braking device, etc., based on information about the outside or inside of the vehicle obtained by the external information detection unit 12030 or the internal information detection unit 12040, and can perform cooperative control for autonomous driving, which enables the vehicle to drive automatically without relying on the driver's operation.

[0133] Additionally, the microcomputer 12051 can output control commands to the body system control unit 12020 based on information about the outside of the vehicle obtained by the external information detection unit 12030. For example, the microcomputer 12051 can perform cooperative control aimed at preventing glare by controlling the headlights to switch from high beam to low beam based on the position of the vehicle in front or oncoming vehicle detected by the external information detection unit 12030.

[0134] The sound / image output unit 12052 sends an output signal of at least one of sound and image to an output device capable of visually or audibly notifying the vehicle occupants or the outside of the vehicle of information. Figure 13 In this example, audio speaker 12061, display unit 12062, and instrument panel 12063 are shown as output devices. For example, display unit 12062 may include at least one of an on-board display and a head-up display.

[0135] Figure 14 This is a diagram showing an example of the mounting position of the imaging unit 12031.

[0136] exist Figure 14 The imaging unit 12031 includes imaging units 12101, 12102, 12103, 12104 and 12105.

[0137] Imaging units 12101, 12102, 12103, 12104, and 12105 are, for example, installed on the front nose, side mirrors, rear bumper, and rear door of vehicle 12100, as well as on the upper part of the windshield inside the vehicle. Imaging unit 12101 installed on the front nose inside the vehicle and imaging unit 12105 installed on the upper part of the windshield primarily acquire images of the front of vehicle 12100. Imaging units 12102 and 12103 installed on the side mirrors primarily acquire images of the sides of vehicle 12100. Imaging unit 12104 installed on the rear bumper or rear door primarily acquires images of the rear of vehicle 12100. Imaging unit 12105 installed on the upper part of the windshield inside the vehicle is mainly used to detect vehicles, pedestrians, obstacles, signals, traffic signs, lanes, etc., ahead.

[0138] It should be noted that Figure 14Examples of the imaging ranges of imaging units 12101 to 12104 are shown. Imaging range 12111 represents the imaging range of imaging unit 12101 installed at the front nose. Imaging ranges 12112 and 12113 represent the imaging ranges of imaging units 12102 and 12103 installed at the side mirrors, respectively. Imaging range 12114 represents the imaging range of imaging unit 12104 installed at the rear bumper or rear door. For example, a bird's-eye view of the vehicle 12100 viewed from above is obtained by overlaying image data captured by imaging units 12101 to 12104.

[0139] At least one of the imaging units 12101 to 12104 may have the function of obtaining distance information. For example, at least one of the imaging units 12101 to 12104 may be a stereo camera composed of multiple imaging elements, or may be an imaging element having pixels for phase difference detection.

[0140] For example, the microcomputer 12051 can determine the distance to each three-dimensional object within the imaging range 12111 to 12114 and the time change of that distance (relative speed relative to the vehicle 12100) based on the distance information obtained from the imaging units 12101 to 12104. This allows it to extract objects existing on the vehicle 12100's travel path, in approximately the same direction as the vehicle 12100, at a predetermined speed (e.g., equal to or greater than 0 km / h). Furthermore, the microcomputer 12051 can preset a following distance to stay ahead of the preceding vehicle and execute automatic braking control (including follow-stop control), automatic acceleration control (including follow-start control), etc. Thus, coordinated control for autonomous driving, enabling the vehicle to drive automatically without relying on driver operation, is possible.

[0141] For example, the microcomputer 12051 can classify three-dimensional object data related to three-dimensional objects into three-dimensional object data such as two-wheeled vehicles, standard vehicles, large vehicles, pedestrians, utility poles, and other three-dimensional objects based on distance information obtained from imaging units 12101 to 12104, extract the classified three-dimensional object data, and use the extracted three-dimensional object data for automatic obstacle avoidance. For example, the microcomputer 12051 identifies obstacles around vehicle 12100 as obstacles that the driver of vehicle 12100 can visually recognize and obstacles that the driver of vehicle 12100 cannot visually recognize. Then, the microcomputer 12051 determines a collision risk indicating the risk of collision with each obstacle. If the collision risk is equal to or higher than a set value and therefore there is a possibility of collision, the microcomputer 12051 outputs a warning to the driver via audio speaker 12061 or display unit 12062, and performs forced deceleration or evasive steering via drive system control unit 12010. The microcomputer 12051 can thereby assist driving to avoid collisions.

[0142] At least one of the imaging units 12101 to 12104 may be an infrared camera that detects infrared light. The microcomputer 12051 can identify a pedestrian, for example, by determining whether a pedestrian exists in the images captured by the imaging units 12101 to 12104. This pedestrian identification is performed, for example, by extracting feature points from the images captured by the imaging units 12101 to 12104, which are infrared cameras, and by performing pattern matching processing on a series of feature points representing the outline of an object to determine whether it is a pedestrian. When the microcomputer 12051 determines that a pedestrian exists in the images captured by the imaging units 12101 to 12104 and thus identifies the pedestrian, the sound / image output unit 12052 controls the display unit 12062 such that a square outline for emphasis is displayed superimposed on the identified pedestrian. The sound / image output unit 12052 can also control the display unit 12062 such that an icon representing the pedestrian is displayed at a desired location.

[0143] Examples of vehicle control systems to which the technology according to this disclosure can be applied have been described above. The technology according to this disclosure can be applied to the imaging unit 12031, the external information detection unit 12030, etc., in the above-described configuration. Specifically, for example, the imaging device 10 (210) can be applied to the imaging unit 12031. By applying the technology according to this disclosure to the imaging unit 12031, it is possible to suppress the influence on imaging while preventing dirt from adhering to the imaging unit 12031. Therefore, more easily viewable captured images can be obtained, thereby reducing driver fatigue.

[0144] The implementation of this technology is not limited to the above-described implementation, and various changes can be made without departing from the spirit of this technology.

[0145] For example, a pattern obtained by combining all or some of the above instances can be used.

[0146] The effects described in this article are merely illustrative and not restrictive, and other effects may be observed.

[0147] This technology can have the following configurations. (1)

[0149] A light detection device, comprising: A photodetector element detects incident light; The light control unit controls the light incident on the light detection element; and A surface portion, which is formed on the incident side of the light relative to the photodetector element, The surface portion includes multiple protrusions regularly arranged on a light-transmitting plate. (2)

[0151] According to the optical detection device described in (1), Among them, several protrusions have light-blocking properties. (3)

[0153] According to the optical detection device described in (1), In the flat plate, the areas with multiple protrusions have light-blocking properties, while the areas without multiple protrusions have light-transmitting properties. (4)

[0155] According to any one of (1) to (3), the light detection device, Multiple protrusions are arranged at predetermined intervals. (5)

[0157] According to any one of (1) to (4), the light detection device, Among them, on the surface of each of the multiple protrusions, there is another protrusion with a different size than the multiple protrusions. (6)

[0159] According to any one of (1) to (5), the light detection device, Among them, there is another protrusion with a different size than the protrusions among the protrusions. (7)

[0161] A thin film for an optical detection device, The optical detection device includes: A photodetector element detects incident light; and The light control unit controls the light incident on the aforementioned light detection element. The aforementioned thin film is formed on the incident side of the light relative to the aforementioned photodetector element. Furthermore, the thin sheet includes multiple protrusions regularly arranged on the plate that transmits light.

[0162] Reference Symbol List

[0163] 10 Imaging Devices

[0164] 11 Surface Part

[0165] 12 lenses

[0166] 13 Imaging Section

[0167] 14 Signal Processing Circuit

[0168] 31 Tablet

[0169] Area 31a

[0170] 32 protrusions

[0171] 70 areas

[0172] 81, 91, 111, 131 protrusions

[0173] 210 Imaging Device

[0174] 211 Surface portion

[0175] 212 Mask

Claims

1. A light detection device, comprising: A photodetector element detects incident light; The light control unit controls the light incident on the light detection element; as well as A surface portion, said surface portion being formed on the incident side of the light relative to the photodetector element, The surface portion includes a plurality of protrusions regularly arranged on the light-transmitting plate.

2. The optical detection device according to claim 1, in, The multiple protrusions have light-blocking properties.

3. The optical detection device according to claim 1, in, In the flat plate, the areas where the plurality of protrusions are formed have light-blocking properties, while the areas where the plurality of protrusions are not formed have light-transmitting properties.

4. The optical detection device according to claim 1, in, The plurality of protrusions are arranged at predetermined intervals.

5. The optical detection device according to claim 1, in, On the surface of each of the plurality of protrusions, there is another protrusion with a different size than the plurality of protrusions.

6. The optical detection device according to claim 1, in, Another protrusion with a different size than the plurality of protrusions is provided between the plurality of protrusions.

7. A thin film for a light detection device, in, The optical detection device includes: A photodetector element detects incident light; and The light control unit controls the light incident on the light detection element. The thin sheet is formed on the incident side of the light relative to the photodetector element. Furthermore, the sheet includes multiple protrusions regularly arranged on a light-transmitting plate.

Images