Image sensor

Abstract

The utility model 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. The image sensor solves the problem that an image sensor in the prior art is difficult to give consideration to both authentic identification capability and low cost at the same time.

Description

Technical Field

[0001] This utility model relates to the field of optical inspection equipment technology, and more specifically, to an image sensor. Background Technology

[0002] Currently, contact image sensors are widely used in the financial industry, primarily for scanning banknotes, recognizing serial numbers, and verifying authenticity. However, banknotes now feature optically variable security threads with perforated windows for anti-counterfeiting purposes. These threads are characterized by their color changing from magenta at a small viewing angle to green when the light or viewing angle increases; they also appear bright when illuminated by monochromatic light at a small viewing angle and black when the light or viewing angle increases. Existing contact image sensors cannot detect this magenta feature, hindering comprehensive counterfeit detection and impacting authentication capabilities. While existing technologies offer some solutions to meet the magenta feature recognition requirements, these involve adding numerous optical components, resulting in a more complex and costly overall device with a larger size.

[0003] In other words, existing image sensors suffer from the problem of simultaneously failing to achieve both counterfeit detection capabilities and low cost. Utility Model Content

[0004] The main objective of this invention is to provide an image sensor that solves the problem that existing image sensors cannot simultaneously achieve both counterfeit detection capability and low cost.

[0005] To achieve the above objectives, this utility model provides an image sensor, comprising: a housing, with a light-transmitting plate disposed on one side of the housing; a photosensitive structure disposed within the housing; a lens structure disposed within the housing and located between the photosensitive structure and the light-transmitting plate, the photosensitive structure being located along the optical axis of the lens structure; and a linear light source structure disposed within the housing and located around the lens structure. The surface to be scanned by the image sensor is located on the side of the light-transmitting plate away from the photosensitive structure, and the light emitted from the linear light source structure illuminates the surface to be scanned. The angle α between the principal ray 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 principal ray direction of the linear light source structure and the optical axis direction of the lens structure are not perpendicular to the light-transmitting plate. The angle b between the principal ray direction of the linear light source structure and the perpendicular line of the light-transmitting plate is equal to or not equal to the angle c between the optical axis direction of the lens structure and the perpendicular line of the light-transmitting plate.

[0007] Furthermore, the angle b between the principal ray 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 principal ray direction of the linear light source structure and the optical axis direction of the lens structure is perpendicular to the light-transmitting plate, and the angle α between the principal ray 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 between the minimum vertical distance d between the linear light source structure and the lens structure and the angle α between the principal ray 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, the 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 stop block disposed in the housing and located on the side of the light-transmitting plate facing the linear light source structure. The stop block avoids the main light direction of the linear light source structure, and the projection of the stop 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 base light source, which is disposed in the housing 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. The angle e between the main ray direction of the base 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, linear light source structures are provided on both opposite sides of a set of lens 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 and is located in the optical axis direction of the lens structure. There are multiple photosensitive chips 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 this utility model, the image sensor includes a housing, a photosensitive structure, a lens structure, and a linear light source structure. A light-transmitting plate is provided on one side of the housing; the photosensitive structure is disposed in the housing; the lens structure is disposed in the housing and located between the photosensitive structure and the light-transmitting plate, with the photosensitive structure located on the optical axis of the lens structure; the linear light source structure is disposed in the housing and located on the periphery 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 from the linear light source structure illuminates the surface to be scanned. The angle α between the principal ray 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 designing a housing, the photosensitive structure, lens structure, and linear light source structure are provided with a suitable space, which helps ensure the operational stability and reliability of these structures. Simultaneously, a light-transmitting plate on one side of the housing seals the internal space, preventing external dust and contaminants from affecting these structures and ensuring detection accuracy. Light emitted from the linear light source structure illuminates the surface to be scanned through the light-transmitting plate. The surface reflects the light carrying image information, which is then transmitted through the light-transmitting plate to the lens structure, where it is imaged onto the photosensitive structure. The photosensitive structure converts the light signal into an electrical signal, thus enabling the identification function. By constraining the angle α between the principal ray direction of the linear light source structure and the optical axis 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 incident light, making the light more perpendicular to the surface to be scanned. When the surface to be scanned is a banknote, this significantly improves the ability to identify the security thread color under small-angle observation, as the specific color of the optically variable ink or security thread is most visible at small-angle incident light.

[0017] Furthermore, by rationally setting the included angle α, the incident angle of the linear light source structure is planned, which not only captures the changes in the optically variable perforated security thread, but also ensures compatibility with other anti-counterfeiting technologies, such as fluorescent ink and infrared ink. This allows the image sensor of this application to detect multiple anti-counterfeiting features in the same device, improving the comprehensiveness and efficiency of authentication and enhancing anti-counterfeiting capabilities. At the same time, no additional optical components are added, reducing costs and simplifying maintenance and replacement. Attached Figure Description

[0018] The accompanying drawings, which form part of this application, are used to provide a further understanding of the present invention. The illustrative embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an undue limitation of the present invention. In the drawings:

[0019] Figure 1 A schematic diagram of the structure of the image sensor according to Embodiment 1 of this utility model is shown;

[0020] Figure 2 A schematic diagram of the structure of an image sensor according to Embodiment 2 of this utility model is shown;

[0021] Figure 3 A schematic diagram of another image sensor according to Embodiment 2 of this utility model is shown;

[0022] Figure 4 A schematic diagram of the image sensor structure according to Embodiment 3 of this utility model is shown;

[0023] Figure 5 A schematic diagram of the image sensor structure of Embodiment 4 of this utility model is shown;

[0024] Figure 6 A schematic diagram of the image sensor structure of Embodiment 5 of this utility model is shown.

[0025] The above figures include the following reference numerals:

[0026] 10. Housing; 20. Light-transmitting plate; 21. Perpendicular 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. Principal ray 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 Implementation

[0027] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0028] It should be noted that, unless otherwise specified, all technical and scientific terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains.

[0029] In this utility model, unless otherwise stated, directional terms such as "upper," "lower," "top," and "bottom" are generally used in relation to the direction shown in the accompanying drawings, or in relation to the vertical, perpendicular, or gravitational direction of the component itself; similarly, for ease of understanding and description, "inner" and "outer" refer to the inner and outer contours of each component itself, but the above directional terms are not used to limit this utility model.

[0030] Because traditional contact image sensors have a large incident angle of light source, they are limited in capturing specific colors (such as magenta) of optically variable security threads with perforated windows, and thus cannot capture magenta, thereby limiting their ability to detect counterfeits.

[0031] To address the problem that existing image sensors cannot simultaneously achieve both counterfeit detection capabilities and low cost, this invention provides an image sensor.

[0032] Example 1

[0033] like Figure 1 As shown, the image sensor includes a housing 10, a photosensitive structure, a lens structure 40, and a linear light source structure 50. A light-transmitting plate 20 is disposed on one side of the housing 10; the photosensitive structure is disposed in the housing 10; the lens structure 40 is disposed in the housing 10 and located between the photosensitive structure and the light-transmitting plate 20, with the photosensitive structure located on the optical axis direction 41 of the lens structure; the linear light source structure 50 is disposed in the housing 10 and located around 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 from the linear light source structure 50 illuminates the surface to be scanned 60. The angle α between the principal ray 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°.

[0034] By providing housing 10, the housing provides a space for the photosensitive structure, lens structure 40, and linear light source structure 50, which helps ensure the operational stability and reliability of these structures. Simultaneously, a light-transmitting plate 20 is provided on one side of the housing 10 to seal its internal space, preventing external dust and contaminants from affecting the internal photosensitive structure, lens structure 40, and linear light source structure 50, thus ensuring detection accuracy. Light emitted from the linear light source structure 50 is transmitted through the light-transmitting plate 20 to the surface 60 to be scanned. The surface 60 reflects the light carrying image information, which is then transmitted through the light-transmitting plate 20 to the lens structure 40, and finally imaged onto the photosensitive structure. The photosensitive structure converts the light signal into an electrical signal, thereby achieving the recognition function. By constraining the angle α between the principal ray 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 incident light, thereby making the light more closely perpendicular to the surface to be scanned 60. When the surface to be scanned 60 is the surface of a banknote, the ability to identify 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 when incident at a small angle.

[0035] Furthermore, by rationally setting the included angle α, the incident angle of the linear light source structure 50 is planned, which not only captures the changes in the optically variable perforated windowed security thread, but also ensures compatibility with other anti-counterfeiting technologies, such as fluorescent ink and infrared ink. This enables the image sensor of this application to detect multiple anti-counterfeiting features in the same device, improving the comprehensiveness and efficiency of authentication and enhancing anti-counterfeiting capabilities. At the same time, no additional optical components are added, reducing costs and simplifying maintenance and replacement.

[0036] It should be noted that the main ray direction 51 of the linear light source structure specifically refers to the central ray direction of the linear light source structure 50, which is a straight line. In this embodiment, the linear light source structure 50 is strip-shaped and can emit one or more of red, green, blue, infrared, and ultraviolet light, which can be set according to the actual situation.

[0037] Furthermore, 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 on 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, which are arranged in a linear array. The photosensitive chips 32 are used to receive the converged light from the lens structure 40, and the circuit board 31 is used to provide circuitry for the photosensitive chips 32. Specifically, the lens structure 40 is strip-shaped, 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 converge the reflected light, or it can be an imaging lens to image the reflected light. The extension direction of the linear light source structure 50 is also parallel to the arrangement direction of the multiple photosensitive chips 32.

[0038] In this application, the surface to be scanned 60 is specifically the surface of a banknote; however, in other alternative embodiments, the surface to be scanned 60 may also be the surface of a product with anti-counterfeiting features. Light emitted from the linear light source structure 50 passes uniformly through the light-transmitting plate 20 at a specific angle to the perpendicular 21 of the light-transmitting plate, and illuminates the surface to be scanned 60.

[0039] In this embodiment, as Figure 1As shown, neither the principal ray direction 51 of the linear light source structure nor the optical axis direction 41 of the lens structure is perpendicular to the light-transmitting plate 20. In other words, neither the principal ray direction 51 of the linear light source structure nor the optical axis direction 41 of the lens structure is perpendicular to the surface 60 to be scanned. At this time, the angle b between the principal ray 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 may be equal to or unequal to the angle c, depending on the actual situation. The angle a between the principal ray direction 51 of the linear light source structure and the optical axis direction 41 of the lens structure is equal to the sum of angle b and angle c; it is only necessary to ensure that the sum of angle b and angle c is less than or equal to 30°. This arrangement allows the linear light source structure 50 to be positioned closer to the lens structure 40, and the angle at which the principal ray of the linear light source structure 50 is incident on the surface 60 to be scanned is smaller, which is beneficial for capturing specific color changes of the light-changing perforated windowed security line under small-angle observation. For example, magenta.

[0040] Specifically, the angle b between the principal ray 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°. This angle b is the incident angle of the principal ray of the linear light source structure 50 onto the surface 60 to be scanned. 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°. By rationally planning the range of these two angles, while ensuring a small incident angle for the linear light source structure 50, the lens structure 40 can receive most of the light reflected from the surface 60 to be scanned. This ensures that the lens structure 40 converges the received light onto the photosensitive chip 32, thereby achieving the recognition of the surface 60 to be scanned, ensuring the image sensor's anti-counterfeiting capability and reliability, while also ensuring high light transmission efficiency and the clarity of the recognized image. In this embodiment, angle b equals 15°, angle c equals 15°, and angle a equals 30°. Although in this embodiment, both included angle b and included angle c are equal to 15°, this value is not intended to limit this application. In other optional embodiments of this application, included angle b and included angle c can be smaller degrees less than 15°, such as 12°, 10°, 7°, 5°, etc.

[0041] 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 closest points of the linear light source structure 50 and the lens structure 40 to each other. When the distance d is small, especially close to 0 mm, the transmission path of 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 rate of light. More light can be effectively focused by the lens structure 40, enhancing the brightness and clarity of image acquisition.

[0042] Furthermore, the smaller d-value allows the light emitted from the linear light source structure 50 to enter the surface 60 to be scanned at a more ideal small angle, ensuring that the light is received by the lens structure 40 at a small angle. This helps improve the design of the optical system, such as reducing the spot size and increasing image resolution. This is particularly important for identifying subtle anti-counterfeiting features, such as the optically variable security thread with a window in the new version of the RMB. By reducing the distance between the linear light source structure 50 and the lens structure 40, the internal structure can be simplified, reducing space requirements and avoiding the use of expensive optical coupling components or complex mechanical positioning devices, thereby reducing manufacturing costs and maintenance complexity.

[0043] Furthermore, this configuration optimizes the utilization of internal space, allowing for a more compact design of the contact-type image sensor. This facilitates miniaturization and integration into various devices, such as ATMs and banknote detectors, improving overall portability and aesthetics. At close range, it also allows for better control and management of stray light in the optical path, reducing background light interference and improving image contrast and clarity, thereby enhancing the ability to identify anti-counterfeiting features. In summary, by controlling the minimum vertical distance d between the linear light source structure 50 and the lens structure 40 to between 0mm and 1.5mm, not only can the optical performance and image acquisition quality of the image sensor be improved, but a low-cost, highly integrated design can also be achieved, demonstrating significant optimization effects for applications such as banknote authentication.

[0044] In this embodiment, d = 1.45 mm.

[0045] Specifically, 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 principal ray 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, this 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 them is precisely controlled. This helps ensure that the light rays traveling from the linear light source structure 50 to the lens structure 40 can more effectively concentrate on illuminating the surface 60 to be scanned, i.e., the area of ​​the banknote to be scanned, especially for detailed anti-counterfeiting features such as the optically variable security thread with a window, enabling more accurate image acquisition. Due to the optimization of the light path, the influence of background stray light can be reduced, improving the clarity of the security thread details during image acquisition. At the same time, by controlling the incident angle of the light, the contrast of the security thread color changes under different viewing angles can be enhanced, which is crucial for feature recognition during the authentication 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 requirements inside the device, making the image sensor design more compact and easy to integrate into various devices, such as ATMs and banknote detectors. At the same time, it reduces the size and weight of the device and improves portability.

[0046] In this embodiment, the ratio between the minimum vertical distance d between the linear light source structure 50 and the lens structure 40 and the angle α between the principal ray direction 51 of the linear light source structure and the optical axis direction 41 of the lens structure is equal to 0.048.

[0047] In this embodiment, there is one linear light source structure 50, located on the periphery of the lens structure 40. However, in other alternative embodiments, there may be multiple linear light source structures 50. Specifically, there may be two linear light source structures 50, with one set of opposing sides of the lens structure 40 each having a linear light source structure 50.

[0048] It should be noted that the light-transmitting plate 20 is placed on one side of the housing 10 to seal the housing 10. The material of the light-transmitting plate 20 can be transparent glass or other transparent materials.

[0049] In this embodiment, the image sensor displays a magenta color when scanning the optically variable security thread with a perforated window on banknotes.

[0050] Example 2

[0051] like Figure 2 and Figure 3 As shown, the image sensor of Embodiment 2 is described.

[0052] The difference between this embodiment and Embodiment 1 is that at least one of the principal ray 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 α between the principal ray 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°. Furthermore, in this embodiment, the lens structure 40 is positioned closer to the light-transmitting plate 20 than the linear light source structure 50, which facilitates mold fabrication.

[0053] exist Figure 2 In this configuration, the optical axis 41 of the lens structure is perpendicular to the light-transmitting plate 20, while the principal ray direction 51 of the linear light source structure is not perpendicular to the light-transmitting plate 20. That is, the optical axis 41 of the lens structure is parallel to the perpendicular line 21 of the light-transmitting plate. At this point, the angle b between the principal ray direction 51 of the linear light source structure and the perpendicular line 21 of the light-transmitting plate is equal to 15°, and this angle b is also the angle a. The angle c between the optical axis 41 of the lens structure and the perpendicular line 21 of the light-transmitting plate is equal to 0°. The distance d is equal to 0.81 mm, and the ratio between the minimum perpendicular distance d between the linear light source structure 50 and the lens structure 40 and the angle a between the principal ray direction 51 of the linear light source structure and the optical axis 41 of the lens structure is equal to 0.054.

[0054] exist Figure 3 In this configuration, the optical axis direction 41 of the lens structure is not perpendicular to the light-transmitting plate 20, while the principal ray direction 51 of the linear light source structure is perpendicular to the light-transmitting plate 20. That is, the principal ray direction 51 of the linear light source structure is parallel to the perpendicular line 21 of the light-transmitting plate. At this point, the angle b between the principal ray direction 51 and the perpendicular line 21 is 0°, and the angle c between the optical axis direction 41 of the lens structure and the perpendicular line 21 is 15°. This angle c is also called angle a. d equals 1.08 mm. The ratio between the minimum perpendicular distance d between the linear light source structure 50 and the lens structure 40 and the angle a between the principal ray direction 51 of the linear light source structure and the optical axis direction 41 of the lens structure is 0.072.

[0055] In this embodiment, the image sensor displays a magenta color when scanning the optically variable security thread with a perforated window on banknotes.

[0056] Example 3

[0057] like Figure 4 As shown, the image sensor of Embodiment 3 is described.

[0058] The difference between this embodiment and Embodiment 2 or Embodiment 1 lies in the structure of the linear light source structure 50. 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 is connected to the edge of the lens structure 40.

[0059] like Figure 4As shown, the array light source includes a light source substrate 52 and multiple LED chips 53 mounted on the side surface of the light source substrate 52 facing the light-transmitting plate 20. These LED chips 53 are arranged linearly. The multiple LED chips 53 are located at the edge of the light source substrate 52 near the lens structure 40. In actual installation, the projection of the light source substrate 52 onto the lens structure 40 can be configured to at least partially cover the ineffective portion of the lens structure 40. This configuration allows the linear array light source to be positioned as close as possible to the lens structure 40.

[0060] In this embodiment, the optical axis direction 41 of the lens structure is perpendicular to the light-transmitting plate 20, while the principal ray direction of the array light source is not perpendicular to the light-transmitting plate 20. At this time, the angle α between the principal ray 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 principal ray direction 51 of the linear light source structure and the perpendicular line 21 of the light-transmitting plate is equal to 15°, and this angle b is also angle α. 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 equals 0 mm, and the ratio between the minimum perpendicular distance d between the linear light source structure 50 and the lens structure 40 and the angle α between the principal ray direction 51 of the linear light source structure and the optical axis direction 41 of the lens structure is equal to 0.

[0061] In this embodiment, the image sensor displays a magenta color when scanning the optically variable security thread with a perforated window on banknotes.

[0062] Example 4

[0063] like Figure 5 As shown, the image sensor of Embodiment 4 is described.

[0064] In this embodiment, the image sensor further includes a block 70, which is disposed in the housing 10 and 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 stray light from the edge of the linear light source structure 50 away from the lens structure 40. At the same time, since the lens structure 40 is set closer 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 stray light from the edge of the linear light source structure 50 near 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 enter the surface to be scanned 60, the impact of stray light from the edge on the scanned image is reduced, which is beneficial to ensuring the clarity and quality of the detected image.

[0065] In this embodiment, the stop 70 is a non-transparent structure and can be glued to the housing 10 or integrally formed with the housing 10. This embodiment can be combined with any of the embodiments one to three above to form a new embodiment.

[0066] In this embodiment, the optical axis direction 41 of the lens structure is perpendicular to the light-transmitting plate 20, while the principal ray direction 51 of the linear light source structure is not perpendicular to the light-transmitting plate 20. That is, the optical axis direction 41 of the lens structure is parallel to the perpendicular line 21 of the light-transmitting plate. At this time, the angle b between the principal ray 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°, specifically equal to 15°. This angle b is also called 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 0.78 mm, and the ratio between the minimum perpendicular distance d between the linear light source structure 50 and the lens structure 40 and the angle a between the principal ray direction 51 of the linear light source structure and the optical axis direction 41 of the lens structure is equal to 0.052.

[0067] In this embodiment, the image sensor displays a magenta color when scanning the optically variable security thread with a perforated window on banknotes.

[0068] Example 5

[0069] like Figure 6 As shown, the image sensor of Embodiment 5 is described.

[0070] The difference between this embodiment and Embodiment 1 is that a basic light source 80 is added.

[0071] In this embodiment, the image sensor also includes a base light source 80. The base light source 80 is disposed in the housing 10 and located on the side of the linear light source structure 50 away from the lens structure 40, or on the side of the lens structure 40 away from the linear light source structure 50. That is, the base light source 80 and the lens structure 40 can be disposed on opposite sides of the linear light source structure 50, or the linear light source structure 50 and the base light source 80 can be disposed on opposite sides of the lens structure 40. The base light source 80 is a conventional light source, and the angle e between the principal ray direction of the base light source 80 and the perpendicular line 21 of the light-transmitting plate is greater than 30° and less than or equal to 80°. Specifically, the angle e shown in the figure is 48°.

[0072] In this embodiment, the base light source 80 can emit one or more of red, green, blue, infrared, and ultraviolet light, which can be set according to actual conditions. By adding the base light source 80, the light emitted by the base light source 80 can achieve scanning of another color of the optically variable windowed security thread, for example, scanning the optically variable windowed security thread to show black. At the same time, normal image scanning function can also be achieved. Thus, when scanning the optically variable windowed security thread of banknotes using the image sensor of this embodiment, not only can a magenta display effect be achieved, but also a black display effect can be achieved. This gives the optically variable windowed security thread two scanning effects, thereby increasing the reliability of anti-counterfeiting identification, and thus the authenticity of the banknote can be determined.

[0073] In this embodiment, the basic light source 80 and the linear light source structure 50 can emit light simultaneously or alternately, depending on the actual situation.

[0074] In this embodiment, the angle α between the principal ray direction 51 of the linear light source structure and the optical axis direction 41 of the lens structure is 28°. d equals 1.47 mm.

[0075] Of course, a basic light source 80, as in this embodiment, can also be added in embodiments two to four to achieve two scanning effects.

[0076] Obviously, the embodiments described above are only some embodiments of this utility model, and not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort should fall within the protection scope of this utility model.

[0077] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0078] It should be noted that the terms "first," "second," etc., used in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented in sequences other than those illustrated or described herein.

[0079] The above description is merely a preferred embodiment of this utility model and is not intended to limit the utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. An image sensor, characterized by, The application relates to an image sensor. The image sensor comprises: a housing (10) provided with a light-transmitting plate (20) on one side; a light-sensing structure arranged in the housing (10); a lens structure (40) arranged in the housing (10) and located between the light-sensing structure and the light-transmitting plate (20), the light-sensing structure being located on the optical axis direction (41) of the lens structure; 2. The image sensor of claim 1, wherein, a linear light source structure (50) arranged in the housing (10) and located on the circumferential side of the lens structure (40), a to-be-scanned surface (60) of the image sensor being located on the side of the light-transmitting plate (20) away from the light-sensing structure, the light rays emitted by the linear light source structure (50) being irradiated on the to-be-scanned surface (60), and the included angle a between the chief ray direction (51) of the linear light source structure and the optical axis direction (41) of the lens structure being greater than 0 degrees and less than or equal to 30 degrees.

3. The image sensor of claim 2, wherein, The chief ray direction (51) of the linear light source structure and the optical axis direction (41) of the lens structure are both not perpendicular to the light-transmitting plate (20), the included angle b between the chief ray direction (51) of the linear light source structure and the perpendicular line (21) of the light-transmitting plate is equal to or not equal to the included angle c between the optical axis direction (41) of the lens structure and the perpendicular line (21) of the light-transmitting plate.

4. The image sensor of claim 1, wherein, The included angle b between the chief ray 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 degrees and less than or equal to 15 degrees, and the included 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 degrees and less than or equal to 15 degrees.

5. The image sensor of claim 1, wherein, At least one of the chief ray 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 included angle a between the chief ray direction (51) of the linear light source structure and the optical axis direction (41) of the lens structure is greater than 0 degrees and less than or equal to 15 degrees.

6. The image sensor of claim 4, wherein, The ratio between the minimum vertical distance d of the linear light source structure (50) and the lens structure (40) and the included angle a between the chief ray 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.

7. The image sensor according to any one of claims 1 to 6, wherein, The minimum vertical distance d of 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. The image sensor further comprises a stop block (70) arranged in the housing (10) and located on the side of the light-transmitting plate (20) facing the linear light source structure (50), the stop block (70) avoids the chief ray direction (51) of the linear light source structure, and the projection of the stop block (70) on the linear light source structure (50) covers at least part 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, wherein, The image sensor further comprises a base light source (80) arranged in the shell (10) and 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 included angle e between a principal ray direction of the base light source (80) and a perpendicular line (21) of 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, wherein, The linear light source structure (50) is one or more, and when the linear light source structure (50) is multiple, the lens structure (40) is provided with the linear light source structure (50) on each of a pair of opposite sides.

10. The image sensor according to any one of claims 1 to 6, wherein, The light-sensing structure comprises a circuit board (31) and a light-sensing chip (32) carried thereon, the light-sensing chip (32) is located on a side of the circuit board (31) facing the lens structure (40), the light-sensing chip (32) is located on an optical axis direction (41) of the lens structure, the light-sensing chip (32) is multiple, the multiple light-sensing chips (32) are arranged in a linear array, 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).

Images