Image sensor

Abstract

The invention provides an image sensor. The image sensor comprises a housing, and one side of the housing is provided with a light-transmitting plate; the photosensitive structure is arranged in the shell; the lens structure is arranged in the shell and located between the photosensitive structure and the light-transmitting plate, and the photosensitive structure is located in the optical axis direction of the lens structure; the linear light source structure is arranged in the shell and located on the peripheral side of the lens structure, the to-be-scanned surface of the image sensor is located on the side, away from the light sensing structure, of the light transmitting plate, and light emitted by the linear light source structure irradiates the to-be-scanned surface; the included angle a between the principal ray direction of the linear light source structure and the optical axis direction of the lens structure is larger than 0 degree and smaller than or equal to 30 degrees. According to the invention, the problem that an image sensor in the prior art is difficult to give consideration to both authentic identification capability and low cost is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of optical detection equipment, and in particular to an image sensor. Background Art

[0002] At present, contact image sensors have been widely used in the financial industry, mainly for image scanning, serial number recognition, and counterfeiting detection of banknotes. However, since the banknotes have added light-changing hollow window security lines for anti-counterfeiting, the characteristics of the light-changing hollow window security lines are: when the observation angle is small, the color is magenta, and when the light angle or observation angle becomes larger, the color of the security line is green; if monochromatic light is used and the observation angle is small, the security line is displayed as highlighted; when the light angle or observation angle becomes larger, the security line is displayed as black. This anti-counterfeiting feature cannot be recognized by the existing contact image sensors, and it is impossible to achieve comprehensive counterfeiting detection, which affects the counterfeiting detection ability. Although the prior art provides some features that can meet the requirements of magenta recognition, more optical elements are added, resulting in more parts of the overall device, which is more complicated, increases the cost, and has a larger overall size.

[0003] That is to say, the image sensors in the prior art have the problem of being difficult to achieve both counterfeit detection capability and low cost at the same time. Summary of the invention

[0004] The main purpose of the present invention is to provide an image sensor to solve the problem that the image sensor in the prior art has difficulty in achieving both counterfeit detection capability and low cost.

[0005] In order to achieve the above-mentioned objectives, the present invention provides an image sensor, comprising: a shell, a light-transmitting plate is arranged on one side of the shell; a photosensitive structure, the photosensitive structure is arranged in the shell; a lens structure, the lens structure is arranged in the shell and is located between the photosensitive structure and the light-transmitting plate, the photosensitive structure is located in the optical axis direction of the lens structure; a linear light source structure, the linear light source structure is arranged in the shell and is located on the peripheral side of the lens structure, the surface to be scanned of the image sensor is located on the side of the light-transmitting plate away from the photosensitive structure, the light emitted by the linear light source structure is irradiated on the surface to be scanned, and the angle a between the main light direction of the linear light source structure and the optical axis direction of the lens structure is greater than 0° and less than or equal to 30°.

[0006] Furthermore, the main light direction of the linear light source structure and the optical axis direction of the lens structure are not perpendicular to the light-transmitting plate, and the angle b between the main light direction of the linear light source structure and the perpendicular line of the light-transmitting plate and the angle c between the optical axis direction of the lens structure and the perpendicular line of the light-transmitting plate are equal or unequal.

[0007] Furthermore, the angle b between the main light direction of the linear light source structure and the perpendicular line of the light-transmitting plate is greater than or equal to 0° and less than or equal to 15°; the angle c between the optical axis direction of the lens structure and the perpendicular line of the light-transmitting plate is greater than or equal to 0° and less than or equal to 15°.

[0008] Furthermore, at least one of the main light direction of the linear light source structure and the optical axis direction of the lens structure is perpendicular to the light-transmitting plate, and an angle a between the main light direction of the linear light source structure and the optical axis direction of the lens structure is greater than 0° and less than or equal to 15°.

[0009] Furthermore, the ratio of the minimum vertical distance d between the linear light source structure and the lens structure to the angle a between the main light direction of the linear light source structure and the optical axis direction of the lens structure is greater than or equal to 0 and less than or equal to 0.4.

[0010] Furthermore, a minimum vertical distance d between the linear light source structure and the lens structure is greater than or equal to 0 mm and less than or equal to 1.5 mm.

[0011] Furthermore, the image sensor also includes a block, which is arranged in the shell and located on the side of the light-transmitting plate facing the linear light source structure. The block avoids the main light direction of the linear light source structure, and the projection of the block on the linear light source structure covers at least a portion of the linear light source structure away from the lens structure.

[0012] Furthermore, the image sensor also includes a basic light source, which is arranged in the shell and located on the side of the linear light source structure away from the lens structure or on the side of the lens structure away from the linear light source structure, and the angle e between the main light direction of the basic light source and the perpendicular line of the light-transmitting plate is greater than 30° and less than or equal to 80°.

[0013] Furthermore, there are one or more linear light source structures. When there are multiple linear light source structures, two opposite sides of a group of lens structures are both provided with linear light source structures.

[0014] Furthermore, the photosensitive structure includes a circuit board and a photosensitive chip mounted thereon. The photosensitive chip is located on the side of the circuit board facing the lens structure. The photosensitive chip is located in the optical axis direction of the lens structure. There are multiple photosensitive chips, and the multiple photosensitive chips are arranged in a linear array. The circuit board is parallel to the light-transmitting plate, and the light-transmitting plate is parallel to the surface to be scanned.

[0015] According to the technical solution of the present invention, the image sensor includes a shell, a photosensitive structure, a lens structure and a linear light source structure, wherein a light-transmitting plate is arranged on one side of the shell; the photosensitive structure is arranged in the shell; the lens structure is arranged in the shell and is located between the photosensitive structure and the light-transmitting plate, and the photosensitive structure is located in the optical axis direction of the lens structure; the linear light source structure is arranged in the shell and is located on the peripheral side of the lens structure, the surface to be scanned of the image sensor is located on the side of the light-transmitting plate away from the photosensitive structure, the light emitted by the linear light source structure is irradiated on the surface to be scanned, and the angle a between the main light direction of the linear light source structure and the optical axis direction of the lens structure is greater than 0° and less than or equal to 30°.

[0016] By setting a shell, the shell provides a space for accommodating the photosensitive structure, the lens structure and the linear light source structure, which is conducive to ensuring the working stability and reliability of the photosensitive structure, the lens structure and the linear light source structure. At the same time, a light-transmitting plate is set on one side of the shell to seal its internal space, so as to prevent external dust and dirt from affecting the internal photosensitive structure, the lens structure and the linear light source structure, which is conducive to ensuring the accuracy of detection. The light emitted by the linear light source structure is irradiated to the surface to be scanned through the light-transmitting plate, and the surface to be scanned reflects the light carrying image information, and transmits it to the lens structure through the light-transmitting plate, and then forms an image in the photosensitive structure. The photosensitive structure is used to convert the light signal into an electrical signal, so as to realize the recognition function. By constraining the angle a between the main light direction of the linear light source structure and the optical axis direction of the lens structure to be greater than 0° and less than or equal to 30°, the linear light source structure can achieve small-angle incidence, so that the light is closer to perpendicular to the surface to be scanned. When the surface to be scanned is the surface of a banknote, the recognition ability of the color of the security line under small-angle observation can be significantly improved, because the specific color of the optically variable ink or the security line is most visible under small-angle incidence.

[0017] In addition, by reasonably setting the angle a and planning the incident angle of the linear light source structure, not only can the changes of the light-variable hollow window security line be captured, but also other anti-counterfeiting technologies such as fluorescent ink, infrared ink, etc. can be compatible. The image sensor of the present application can detect multiple anti-counterfeiting features in the same device, improving the comprehensiveness and efficiency of counterfeiting detection and enhancing the anti-counterfeiting ability. At the same time, no additional optical elements are added, which reduces costs and also reduces the complexity of maintenance and replacement. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The drawings constituting a part of the present application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0019] Figure 1 A schematic diagram showing the structure of an image sensor according to a first embodiment of the present invention is shown;

[0020] Figure 2 A schematic diagram of the structure of an image sensor according to a second embodiment of the present invention is shown;

[0021] Figure 3 A schematic diagram showing the structure of another image sensor according to the second embodiment of the present invention is shown;

[0022] Figure 4 A schematic diagram showing the structure of an image sensor according to a third embodiment of the present invention is shown;

[0023] Figure 5 A schematic diagram showing the structure of an image sensor according to a fourth embodiment of the present invention is shown;

[0024] Figure 6 A schematic diagram showing the structure of an image sensor according to a fifth embodiment of the present invention is shown;

[0025] Figure 7 A scanning effect diagram of an image sensor according to an optional embodiment of the present invention is shown;

[0026] Figure 8 Shows Figure 6 The scanning effect diagram obtained by the light emitted by the basic light source.

[0027] The above drawings include the following reference numerals:

[0028] 10. Shell; 20. Light-transmitting plate; 21. Vertical line of the light-transmitting plate; 31. Circuit board; 32. Photosensitive chip; 40. Lens structure; 41. Optical axis direction of the lens structure; 50. Linear light source structure; 51. Main light direction of the linear light source structure; 52. Light source substrate; 53. LED chip; 60. Surface to be scanned; 70. Block; 80. Basic light source. DETAILED DESCRIPTION

[0029] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0030] It should be noted that, unless otherwise specified, all technical and scientific terms used in this application have the same meanings as commonly understood by ordinary technicians in the technical field to which this application belongs.

[0031] In the present invention, unless otherwise specified, the directional words used, such as "up, down, top, bottom", usually refer to the directions shown in the drawings, or to the components themselves in the vertical, perpendicular or gravity directions; similarly, for ease of understanding and description, "inside and outside" refer to the inside and outside relative to the outline of each component itself, but the above-mentioned directional words are not used to limit the present invention.

[0032] Since the incident angle of the light source of the traditional contact image sensor is large, it has limitations when capturing the specific color of the light-variable hollow window security thread (such as magenta), and is unable to capture magenta, thus limiting its counterfeit detection ability.

[0033] In order to solve the problem that it is difficult to achieve both counterfeit detection capability and low cost at the same time in the image sensor in the prior art, the present invention provides an image sensor.

[0034] Embodiment 1

[0035] like Figure 1 and Figure 7 As shown, the image sensor includes a shell 10, a photosensitive structure, a lens structure 40 and a linear light source structure 50, a light-transmitting plate 20 is arranged on one side of the shell 10; the photosensitive structure is arranged in the shell 10; the lens structure 40 is arranged in the shell 10 and is located between the photosensitive structure and the light-transmitting plate 20, and the photosensitive structure is located on the optical axis direction 41 of the lens structure; the linear light source structure 50 is arranged in the shell 10 and is located on the peripheral side of the lens structure 40, the surface 60 to be scanned of the image sensor is located on the side of the light-transmitting plate 20 away from the photosensitive structure, the light emitted by the linear light source structure 50 irradiates the surface 60 to be scanned, and the angle a between the main light direction 51 of the linear light source structure and the optical axis direction 41 of the lens structure is greater than 0° and less than or equal to 30°.

[0036] By setting the housing 10, the housing 10 provides a housing space for the photosensitive structure, the lens structure 40 and the linear light source structure 50, which is conducive to ensuring the working stability and reliability of the photosensitive structure, the lens structure 40 and the linear light source structure 50. At the same time, a light-transmitting plate 20 is provided on one side of the housing 10 to achieve sealing of its internal space, thereby preventing external dust and dirt from affecting the internal photosensitive structure, the lens structure 40 and the linear light source structure 50, which is conducive to ensuring the accuracy of detection. The light emitted by the linear light source structure 50 is irradiated to the surface to be scanned 60 through the light-transmitting plate 20, and the surface to be scanned 60 reflects the light carrying the image information and transmits it to the lens structure 40 through the light-transmitting plate 20, and then forms an image in the photosensitive structure. The photosensitive structure is used to convert the optical signal into an electrical signal, thereby realizing the recognition function. By constraining the angle a between the main light direction 51 of the linear light source structure and the optical axis direction 41 of the lens structure to be greater than 0° and less than or equal to 30°, the linear light source structure 50 can achieve small-angle incidence, so that the light is closer to perpendicular to the surface 60 to be scanned. When the surface 60 to be scanned is the surface of a banknote, the ability to recognize the color of the security thread under small-angle observation can be significantly improved, because the specific color of the optically variable ink or the security thread is most visible under small-angle incidence.

[0037] In addition, by reasonably setting the angle a and planning the incident angle of the linear light source structure 50, not only can the changes of the light-variable hollow window security line be captured, but also other anti-counterfeiting technologies such as fluorescent ink, infrared ink, etc. can be compatible. The image sensor of the present application can detect multiple anti-counterfeiting features in the same device, improving the comprehensiveness and efficiency of counterfeiting identification and enhancing the anti-counterfeiting ability. At the same time, no additional optical elements are added, which reduces costs and also reduces the complexity of maintenance and replacement.

[0038] It should be noted that the main light direction 51 of the linear light source structure specifically refers to the central light direction of the linear light source structure 50, which is a straight line. In this embodiment, the linear light source structure 50 is in a bar shape, and the linear light source structure 50 can emit one or more of red light, green light, blue light, infrared light, and ultraviolet light, which can be set according to actual conditions.

[0039] In addition, the photosensitive structure includes a circuit board 31 and a photosensitive chip 32 mounted thereon. The circuit board 31 is located on one side of the internal space of the housing 10, and the circuit board 31 and the light-transmitting plate 20 are respectively located on a set of opposite sides of the housing 10. The photosensitive chip 32 is located on the side of the circuit board 31 facing the lens structure 40, and the photosensitive chip 32 is located in the optical axis direction 41 of the lens structure. The circuit board 31 is parallel to the light-transmitting plate 20, and the light-transmitting plate 20 is parallel to the surface to be scanned 60. There are multiple photosensitive chips 32, and the multiple photosensitive chips 32 are arranged in a linear array. The photosensitive chip 32 is used to receive the converged light of the lens structure 40, and the circuit board 31 is used to provide a circuit for the photosensitive chip 32. Specifically, the lens structure 40 is in a strip shape, and the extension direction of the strip-shaped lens structure 40 is parallel to the arrangement direction of the multiple photosensitive chips 32. The lens structure 40 can be a focusing lens to achieve convergence of reflected light; it can also be an imaging lens to achieve imaging of reflected light. The extension direction of the linear light source structure 50 is also parallel to the arrangement direction of the plurality of photosensitive chips 32 .

[0040] In the present application, the surface to be scanned 60 is specifically the surface of a banknote, but in other optional embodiments, the surface to be scanned 60 may also be the surface of a product with anti-counterfeiting properties. The light emitted from the linear light source structure 50 is uniformly transmitted through the light-transmitting plate 20 along the main scanning direction at a specific angle to the vertical line 21 of the light-transmitting plate, and irradiates the surface to be scanned 60.

[0041] In this embodiment, if Figure 1As shown, the main light direction 51 of the linear light source structure and the optical axis direction 41 of the lens structure are not perpendicular to the light-transmitting plate 20, that is, the main light direction 51 of the linear light source structure and the optical axis direction 41 of the lens structure are not perpendicular to the surface 60 to be scanned. At this time, the angle b between the main light direction 51 of the linear light source structure and the vertical line 21 of the light-transmitting plate and the angle c between the optical axis direction 41 of the lens structure and the vertical line 21 of the light-transmitting plate are equal or unequal, and can be set according to actual conditions. The angle a between the main light direction 51 of the linear light source structure and the optical axis direction 41 of the lens structure = angle b + angle c, and it is only necessary to ensure that the sum of angle b and angle c is less than or equal to 30°. This arrangement enables the linear light source structure 50 to be arranged closer to the lens structure 40, and the main light of the linear light source structure 50 is incident on the surface 60 to be scanned at a smaller angle, which is conducive to capturing the specific color changes of the light-variable hollow window security line under small-angle observation. For example, magenta.

[0042] Specifically, the angle b between the main light direction 51 of the linear light source structure and the vertical line 21 of the light-transmitting plate is greater than or equal to 0° and less than or equal to 15°. The angle b between the main light direction 51 of the linear light source structure and the vertical line 21 of the light-transmitting plate is the incident angle of the main light of the linear light source structure 50 incident on the surface to be scanned 60. The angle c between the optical axis direction 41 of the lens structure and the vertical line 21 of the light-transmitting plate is greater than or equal to 0° and less than or equal to 15°. By rationally planning the range of the two angles, while ensuring the small incident angle of the linear light source structure 50, the lens structure 40 can receive most of the light reflected by the surface to be scanned 60, thereby ensuring that the lens structure 40 converges the received light to the photosensitive chip 32, thereby realizing the recognition of the surface to be scanned 60, ensuring the counterfeit detection ability and reliability of the image sensor, and at the same time ensuring the light transmission efficiency and the clarity of the recognized image. In this embodiment, the angle b is equal to 15°, the angle c is equal to 15°, and the angle a is equal to 30°. Although in the present embodiment, the angle b and the angle c are both equal to 15°, this value cannot be used as a limitation of the present application. In other optional embodiments of the present application, the angle b and the angle c can be smaller degrees less than 15°, such as 12°, 10°, 7°, 5°, etc.

[0043] like Figure 1 As shown, the minimum vertical distance d between the linear light source structure 50 and the lens structure 40 is greater than or equal to 0 mm and less than or equal to 1.5 mm. Specifically, the minimum vertical distance between the linear light source structure 50 and the lens structure 40 refers to the length of the line connecting the points where the linear light source structure 50 and the lens structure 40 are closest to each other. When the distance d is small, especially close to 0 mm, the transmission path of the light from the linear light source structure 50 to the lens structure 40 is shortened, which means that less light will be scattered or absorbed, thereby improving the utilization of light. More light can be effectively focused by the lens structure 40, enhancing the brightness and clarity of image acquisition.

[0044] In addition, the smaller d value enables the light emitted by the linear light source structure 50 to enter the scanned surface 60 at a more ideal small angle, and ensures that the light is received by the lens structure 40 at a small angle, which helps to improve the design of the optical system, such as reducing the spot size and improving the resolution of the image. This is particularly important for identifying subtle anti-counterfeiting features, such as the light-changing hollow window security line in the new version of RMB. By reducing the distance between the linear light source structure 50 and the lens structure 40, the internal structure can be simplified, the space requirement can be reduced, and the use of expensive optical coupling components or complex mechanical positioning devices can be avoided, thereby reducing the manufacturing cost and maintenance complexity.

[0045] In addition, such a setting also optimizes the utilization of the internal space of the device, so that the entire contact image sensor can be designed to be more compact, which is conducive to the realization of miniaturization and is easy to integrate into various devices, such as ATMs, banknote detectors, etc., to improve the overall portability and aesthetics of the device. Moreover, at a close distance, the stray light in the optical path can be better controlled and managed, the interference of background light can be reduced, the contrast and clarity of image acquisition can be improved, and the recognition ability of anti-counterfeiting features can be enhanced. In summary, by controlling the minimum vertical distance d between the linear light source structure 50 and the lens structure 40 to be between 0 mm and 1.5 mm, not only can the optical performance and image acquisition quality of the image sensor be improved, but also the low-cost and high-integration design of the device can be achieved, which has a significant optimization effect on application scenarios such as banknote counterfeiting.

[0046] In this embodiment, d=1.45 mm.

[0047] Specifically, the ratio of the minimum vertical distance d between the linear light source structure 50 and the lens structure 40 to the angle a between the main light direction 51 of the linear light source structure and the optical axis direction 41 of the lens structure is greater than or equal to 0 and less than or equal to 0.4. Preferably, the ratio is greater than or equal to 0 and less than or equal to 0.3. Keeping d / a within a small range means that the relationship between the distance between the linear light source structure 50 and the lens structure 40 and the angle between the two is precisely controlled. This helps to ensure that the light can be concentratedly illuminated on the surface to be scanned 60, that is, the area to be scanned of the banknote in a more effective manner during the process of reaching the lens structure 40 from the linear light source structure 50, especially for anti-counterfeiting features with rich details such as light-changing hollow window security lines, more accurate image acquisition can be achieved. Due to the optimization of the light path, the influence of background stray light can be reduced, and the clarity of the security line details during image acquisition can be improved. At the same time, by controlling the incident angle of the light, the contrast of the color change of the security line at different observation angles can be enhanced, which is crucial for feature recognition in the counterfeit detection process. The small d / a indicates that the linear light source structure 50 and the lens structure 40 are close to each other, which reduces the space requirement inside the device, making the image sensor design more compact and easy to integrate into various devices, such as ATMs, banknote detectors, etc., while reducing the size and weight of the device and improving portability.

[0048] In this embodiment, the ratio of the minimum vertical distance d between the linear light source structure 50 and the lens structure 40 to the angle a between the main light direction 51 of the linear light source structure and the optical axis direction 41 of the lens structure is equal to 0.048.

[0049] In this embodiment, there is one linear light source structure 50, and one linear light source structure 50 is located on the peripheral side of the lens structure 40. However, in other optional embodiments, there may be multiple linear light source structures 50, and when there are multiple linear light source structures 50, there may be two linear light source structures 50, and a group of opposite sides of the lens structure 40 are both provided with linear light source structures 50.

[0050] It should be noted that the light-transmitting plate 20 is covered on one side of the housing 10 to seal the housing 10 . The light-transmitting plate 20 may be made of transparent glass or other transparent materials.

[0051] The scanning effect of the image sensor of this embodiment on the light-changing hollow window security line of banknotes can be referred to Figure 7 As shown in , it appears magenta.

[0052] Embodiment 2

[0053] like Figure 2 and Figure 3 As shown, the image sensor of the second embodiment is described.

[0054] The difference between this embodiment and the first embodiment is that at least one of the main light direction 51 of the linear light source structure and the optical axis direction 41 of the lens structure is perpendicular to the light-transmitting plate 20, and the angle a between the main light direction 51 of the linear light source structure and the optical axis direction 41 of the lens structure is greater than 0° and less than or equal to 15°. In this embodiment, the lens structure 40 is arranged closer to the light-transmitting plate 20 than the linear light source structure 50, and such an arrangement facilitates the production of the mold.

[0055] exist Figure 2 , the optical axis direction 41 of the lens structure is perpendicular to the light-transmitting plate 20, and the main light direction 51 of the linear light source structure is not perpendicular to the light-transmitting plate 20. In other words, the optical axis direction 41 of the lens structure is parallel to the vertical line 21 of the light-transmitting plate. At this time, the angle b between the main light direction 51 of the linear light source structure and the vertical line 21 of the light-transmitting plate is equal to 15°, and the angle b is also the angle a. The angle c between the optical axis direction 41 of the lens structure and the vertical line 21 of the light-transmitting plate is equal to 0°. d is equal to 0.81 mm, and the ratio of the minimum vertical distance d between the linear light source structure 50 and the lens structure 40 to the angle a between the main light direction 51 of the linear light source structure and the optical axis direction 41 of the lens structure is equal to 0.054.

[0056] exist Figure 3 In the embodiment, the optical axis direction 41 of the lens structure is not perpendicular to the light-transmitting plate 20, and the main light direction 51 of the linear light source structure is arranged perpendicular to the light-transmitting plate 20. That is to say, the main light direction 51 of the linear light source structure is parallel to the vertical line 21 of the light-transmitting plate. At this time, the angle b between the main light direction 51 of the linear light source structure and the vertical line 21 of the light-transmitting plate is equal to 0°, and the angle c between the optical axis direction 41 of the lens structure and the vertical line 21 of the light-transmitting plate is equal to 15°, which is also the angle a. d is equal to 1.08 mm. The ratio between the minimum vertical distance d between the linear light source structure 50 and the lens structure 40 and the angle a between the main light direction 51 of the linear light source structure and the optical axis direction 41 of the lens structure is 0.072.

[0057] The scanning effect of the image sensor of this embodiment on the light-changing hollow window security line of banknotes can be referred to Figure 7 As shown in , it appears magenta.

[0058] Embodiment 3

[0059] like Figure 4 As shown, the image sensor of the third embodiment is described.

[0060] The difference between this embodiment and the second embodiment or the first embodiment is that the structure of the linear light source structure 50 is different. In this embodiment, the linear light source structure 50 is specifically an array light source. The array light source is located on the side of the lens structure 40 facing the light-transmitting plate 20 and connected to the edge of the lens structure 40.

[0061] like Figure 4 As shown, the array light source includes a light source substrate 52 and an LED chip 53 mounted on a surface of the light source substrate 52 facing the light-transmitting plate 20. There are multiple LED chips 53, and the multiple LED chips 53 are arranged linearly. The multiple LED chips 53 are located at the edge of the light source substrate 52 close to the lens structure 40. During actual installation, the projection of the light source substrate 52 on the lens structure 40 can be set to at least partially cover the invalid part of the lens structure 40, so that the linear array light source can be set as close to the lens structure 40 as possible.

[0062] In the present embodiment, the optical axis direction 41 of the lens structure is perpendicular to the light-transmitting plate 20, and the main light direction of the array light source is not perpendicular to the light-transmitting plate 20. At this time, the angle a between the main light direction 51 of the linear light source structure and the optical axis direction 41 of the lens structure is greater than 0° and less than or equal to 15°. The angle b between the main light direction 51 of the linear light source structure and the perpendicular line 21 of the light-transmitting plate is equal to 15°, and the angle b is also the angle a. The angle c between the optical axis direction 41 of the lens structure and the perpendicular line 21 of the light-transmitting plate is equal to 0°. d is equal to 0 mm, and the ratio of the minimum vertical distance d between the linear light source structure 50 and the lens structure 40 to the angle a between the main light direction 51 of the linear light source structure and the optical axis direction 41 of the lens structure is equal to 0.

[0063] The scanning effect of the image sensor of this embodiment on the light-changing hollow window security line of banknotes can be referred to Figure 7 As shown in , it appears magenta.

[0064] Embodiment 4

[0065] like Figure 5 As shown, an image sensor according to a fourth embodiment is described.

[0066] In this embodiment, the image sensor also includes a block 70, which is disposed in the shell 10 and is located on the side of the light-transmitting plate 20 facing the linear light source structure 50. The block 70 is located on the right side of the lens structure 40. The block 70 avoids the main light direction 51 of the linear light source structure, and the projection of the block 70 on the linear light source structure 50 covers at least a portion of the linear light source structure 50 away from the lens structure 40. By setting the block 70, the block 70 can block the edge stray light of the linear light source structure 50 on the side away from the lens structure 40. At the same time, since the lens structure 40 is arranged close to the light-transmitting plate 20 relative to the linear light source structure 50, and the projection of the lens structure 40 on the linear light source structure 50 at least partially covers at least a part of the left side of the linear light source structure 50, the edge stray light of the linear light source structure 50 on the side close to the lens structure 40 can be blocked and intercepted by the lens structure 40. Under the premise of ensuring that the main light of the linear light source structure 50 can stably pass between the lens structure 40 and the block 70 and then be shot into the surface to be scanned 60, the influence of the edge stray light on the scanning image is reduced, which is beneficial to ensure the clarity and quality of the detected image.

[0067] In this embodiment, the stopper 70 is a non-transparent structure, and can be bonded to the housing 10 by a glue structure, or can be integrally formed with the housing 10. This embodiment can be combined with any one of the above-mentioned embodiments 1 to 3 to form a new embodiment.

[0068] In the present embodiment, the optical axis direction 41 of the lens structure is perpendicular to the light-transmitting plate 20, and the main light direction 51 of the linear light source structure is not perpendicular to the light-transmitting plate 20. In other words, the optical axis direction 41 of the lens structure is parallel to the vertical line 21 of the light-transmitting plate. At this time, the angle b between the main light direction 51 of the linear light source structure and the vertical line 21 of the light-transmitting plate is greater than or equal to 0° and less than or equal to 15°, specifically equal to 15°, and the angle b is also the angle a. The angle c between the optical axis direction 41 of the lens structure and the vertical line 21 of the light-transmitting plate is equal to 0°. d is equal to 0.78 mm, and the ratio of the minimum vertical distance d between the linear light source structure 50 and the lens structure 40 to the angle a between the main light direction 51 of the linear light source structure and the optical axis direction 41 of the lens structure is equal to 0.052.

[0069] The scanning effect of the image sensor of this embodiment on the light-changing hollow window security line of banknotes can be referred to Figure 7 As shown in , it appears magenta.

[0070] Embodiment 5

[0071] like Figure 6 As shown, an image sensor according to a fifth embodiment is described.

[0072] The difference between this embodiment and the first embodiment is that a basic light source 80 is added.

[0073] In this embodiment, the image sensor further includes a basic light source 80, which is disposed in the housing 10 and is located on a side of the linear light source structure 50 away from the lens structure 40, or on a side of the lens structure 40 away from the linear light source structure 50. That is, the basic light source 80 and the lens structure 40 can be divided into being disposed on both sides of the linear light source structure 50, or the linear light source structure 50 and the basic light source 80 can be disposed on both sides of the lens structure 40, respectively. The basic light source 80 is an existing light source, and the angle e between the main light direction of the basic light source 80 and the vertical line 21 of the light-transmitting plate is greater than 30° and less than or equal to 80°. The angle e specifically shown in the figure is equal to 48°.

[0074] In this embodiment, the basic light source 80 can emit one or more of red light, green light, blue light, infrared light, and ultraviolet light, and can be set according to actual conditions. By adding the basic light source 80, the light emitted by the basic light source 80 can realize the scanning of another color of the light-changing hollow window security line, for example, scanning the light-changing hollow window security line to appear black. At the same time, the normal image scanning function can also be realized. In this way, the image sensor of this embodiment is used to scan the light-changing hollow window security line of the banknote, which can not only realize the following Figure 7 The magenta rendering effect shown can also be achieved as follows Figure 8 The black presentation effect shown makes the light-variable hollow window security line have two scanning effects, thereby increasing the reliability of anti-counterfeiting identification, and thus the authenticity of the banknote can be judged accordingly.

[0075] In this embodiment, the basic light source 80 and the linear light source structure 50 can emit light simultaneously or alternately, which can be set according to actual conditions.

[0076] In this embodiment, the angle a between the main light direction 51 of the linear light source structure and the optical axis direction 41 of the lens structure is 28°, and d is equal to 1.47 mm.

[0077] Of course, a basic light source 80 as in this embodiment may also be added to the second to fourth embodiments to achieve two scanning effects.

[0078] Obviously, the above-described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0079] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0080] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the numbers used in this way can be interchanged where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein.

[0081] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. An image sensor, characterized in that: include: A housing (10), wherein a light-transmitting plate (20) is provided on one side of the housing (10); A photosensitive structure, the photosensitive structure being arranged in the housing (10); A lens structure (40), the lens structure (40) being arranged in the housing (10) and located between the photosensitive structure and the light-transmitting plate (20), the photosensitive structure being located in the optical axis direction (41) of the lens structure; A linear light source structure (50), wherein the linear light source structure (50) is arranged in the housing (10) and is located on the peripheral side of the lens structure (40); the surface to be scanned (60) of the image sensor is located on the side of the light-transmitting plate (20) away from the photosensitive structure; the light emitted by the linear light source structure (50) irradiates the surface to be scanned (60); and the angle a between the main light direction (51) of the linear light source structure and the optical axis direction (41) of the lens structure is greater than 0° and less than or equal to 30°.

2. The image sensor according to claim 1, characterized in that The main light direction (51) of the linear light source structure and the optical axis direction (41) of the lens structure are not arranged perpendicular to the light-transmitting plate (20), and the angle b between the main light direction (51) of the linear light source structure and the perpendicular line (21) of the light-transmitting plate and the angle c between the optical axis direction (41) of the lens structure and the perpendicular line (21) of the light-transmitting plate are equal to or unequal to each other.

3. The image sensor according to claim 2, characterized in that The angle b between the main light direction (51) of the linear light source structure and the perpendicular line (21) of the light-transmitting plate is greater than or equal to 0° and less than or equal to 15°; the angle c between the optical axis direction (41) of the lens structure and the perpendicular line (21) of the light-transmitting plate is greater than or equal to 0° and less than or equal to 15°.

4. The image sensor according to claim 1, characterized in that At least one of the main light direction (51) of the linear light source structure and the optical axis direction (41) of the lens structure is perpendicular to the light-transmitting plate (20), and an angle a between the main light direction (51) of the linear light source structure and the optical axis direction (41) of the lens structure is greater than 0° and less than or equal to 15°.

5. The image sensor according to claim 1, characterized in that The ratio of the minimum vertical distance d between the linear light source structure (50) and the lens structure (40) to the angle a between the main light direction (51) of the linear light source structure and the optical axis direction (41) of the lens structure is greater than or equal to 0 and less than or equal to 0.

4.

6. The image sensor according to claim 4, characterized in that: The minimum vertical distance d between the linear light source structure (50) and the lens structure (40) is greater than or equal to 0 mm and less than or equal to 1.5 mm.

7. The image sensor according to any one of claims 1 to 6, characterized in that: The image sensor further comprises a block (70), the block (70) being arranged in the housing (10) and located on a side of the light-transmitting plate (20) facing the linear light source structure (50), the block (70) avoiding the main light direction (51) of the linear light source structure, and the projection of the block (70) on the linear light source structure (50) covering at least a portion of the linear light source structure (50) away from the lens structure (40).

8. The image sensor according to any one of claims 1 to 6, characterized in that: The image sensor further comprises a basic light source (80), wherein the basic light source (80) is arranged in the housing (10) and is located on a side of the linear light source structure (50) away from the lens structure (40) or on a side of the lens structure (40) away from the linear light source structure (50), and an angle e between a main light direction of the basic light source (80) and a perpendicular line (21) to the light-transmitting plate is greater than 30° and less than or equal to 80°.

9. The image sensor according to any one of claims 1 to 6, characterized in that: There are one or more linear light source structures (50). When there are multiple linear light source structures (50), the linear light source structures (50) are arranged on two opposite sides of a group of the lens structure (40).

10. The image sensor according to any one of claims 1 to 6, characterized in that: The photosensitive structure comprises a circuit board (31) and a photosensitive chip (32) mounted thereon, the photosensitive chip (32) being located on a side of the circuit board (31) facing the lens structure (40), the photosensitive chip (32) being located in the optical axis direction (41) of the lens structure, the photosensitive chips (32) being multiple, and the multiple photosensitive chips (32) being arranged in a linear array, the circuit board (31) being parallel to the light-transmitting plate (20), and the light-transmitting plate (20) being parallel to the surface to be scanned (60).

Images