A fixed focus lens and video communication imaging device

Abstract

The embodiment of the present application discloses a kind of fixed focus lens and video communication imaging equipment.The fixed focus lens is sequentially arranged by setting first lens, second lens, third lens, fourth lens, fifth lens, sixth lens and seventh lens from object side to image side along optical axis;First lens, second lens and sixth lens have negative focal power, third lens, fourth lens, fifth lens and seventh lens have positive focal power;And limit the focal power of first lens, third lens, fifth lens, sixth lens, seventh lens and entire fixed focus lens meet certain proportion range, can control optical distortion less than 3%, diagonal field angle is controlled between 80~100 °, finally realizes a kind of wide-angle small distortion lens scheme of large image surface.

Description

Technical Field

[0001] This invention relates to the field of optical system technology, and more particularly to a fixed-focus lens and a video communication imaging device. Background Technology

[0002] With the widespread use of video calls and video conferencing across various industries, their convenience and ease of use have profoundly changed the way people communicate and exchange information.

[0003] As the video communication product market continues to expand, the shortcomings of its video communication lens products are gradually becoming apparent: the field of view is small, making it unable to capture a wide range of scene information; the distortion is large, resulting in distorted images that affect the viewing experience; and the compatible sensors are small in size, failing to provide rich scene and image details. Summary of the Invention

[0004] This invention provides a fixed-focus lens and a video communication imaging device to achieve a large image area, wide-angle, and low-distortion lens solution that meets the lens requirements for video communication.

[0005] In a first aspect, embodiments of the present invention provide a fixed-focus lens, comprising a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, and a seventh lens arranged sequentially along the optical axis from the object plane to the image plane; The first lens, the second lens, and the sixth lens have negative optical power, while the third lens, the fourth lens, the fifth lens, and the seventh lens have positive optical power. Some of the lenses from the first to the seventh lens satisfy the following condition: -0.291 < φ1 / φ < -0.241; 0.463 < φ3 / φ < 0.544; 0.421 < φ5 / φ < 0.491; -0.999 < φ6 / φ < -0.922; 0.425 < φ7 / φ < 0.474; Wherein, φ1, φ3, φ5, φ6, φ7, and φ represent the optical power of the first lens, the third lens, the fifth lens, the sixth lens, the seventh lens, and the entire fixed-focus lens, respectively.

[0006] Optionally, the object plane side of the first lens is convex, and the image plane side is concave. The image plane side of the second lens is concave; The image plane side of the third lens is convex; The object plane side of the fourth lens is convex, and the image plane side is also convex. The object plane side of the fifth lens is convex, and the image plane side is also convex. The object plane side of the sixth lens is concave, and the image plane side is also concave. The object plane side of the seventh lens is convex, and the image plane side is also convex.

[0007] Optionally, the opposing surfaces of the fifth lens and the sixth lens are glued together to form a cemented lens assembly.

[0008] Optionally, some of the lenses from the first lens to the seventh lens satisfy the following condition: 1.60 <ND1<1.65; 1.61 <ND5<1.66; 1.74 <ND6<1.80; 1.51 <ND7<1.58; Wherein, ND1, ND5, ND6, and ND7 are the refractive indices of the first lens, the fifth lens, the sixth lens, and the seventh lens, respectively.

[0009] Optionally, some of the lenses from the first lens to the seventh lens satisfy the following condition: 50.1 <VD1<72.3; 46.8 <VD2<66.7; 49.7 <VD5<66.8; 54.8 <VD7<70.3; Wherein, VD1, VD2, VD5, and VD7 are the Abbe constants of the first lens, the second lens, the fifth lens, and the seventh lens, respectively.

[0010] Optionally, the fourth lens satisfies the following condition: 1.72 <ND4<1.77; Wherein, ND4 is the refractive index of the fourth lens.

[0011] Optionally, the second lens and the seventh lens are aspherical plastic lenses, and the first lens, the third lens, the fourth lens, the fifth lens and the sixth lens are spherical glass lenses.

[0012] Optionally, the fixed-focus lens satisfies the following condition: 0.308 <BFL / ImgH<0.532; Wherein, BFL represents the distance from the image-side surface of the seventh lens to the imaging surface, and ImgH is the diagonal length of the effective imaging area on the imaging surface.

[0013] In a second aspect, embodiments of the present invention also provide a video communication imaging device, including a fixed-focus lens as described in any of the first aspects.

[0014] The technical solution of this invention, by setting a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, and a seventh lens arranged sequentially along the optical axis from the object side to the image side; the first lens, the second lens, and the sixth lens have negative optical power, and the third lens, the fourth lens, the fifth lens, and the seventh lens have positive optical power; and by limiting the optical power of the first lens, the third lens, the fifth lens, the sixth lens, the seventh lens, and the entire fixed-focus lens to meet a certain proportional range, optical distortion can be controlled to be less than 3%, and the diagonal field of view can be controlled between 80 and 100°, ultimately achieving a lens solution with a large image plane, wide angle, and small distortion. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the structure of a fixed-focus lens provided in Embodiment 1 of the present invention; Figure 2 yes Figure 1 The spherical aberration curve of the fixed-focus lens in Embodiment 1 is shown below; Figure 3 yes Figure 1 Field curvature distortion diagram of the fixed-focus lens in Embodiment 1 shown; Figure 4 This is a schematic diagram of the structure of a fixed-focus lens provided in Embodiment 2 of the present invention; Figure 5 yes Figure 4 The spherical aberration curve of the fixed-focus lens in Embodiment 2 is shown below; Figure 6 yes Figure 4 Field curvature distortion diagram of the fixed-focus lens in Embodiment 2 shown. Detailed Implementation

[0016] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the present invention, and not all of the structures.

[0017] The terminology used in the embodiments of this invention is for the purpose of describing specific embodiments only and is not intended to limit the invention. It should be noted that directional terms such as "upper," "lower," "left," and "right" described in the embodiments of this invention are used to describe the angles shown in the accompanying drawings and should not be construed as limiting the embodiments of this invention. Furthermore, in the context, it should be understood that when referring to an element being formed "on" or "below" another element, it can be formed not only directly on or below the other element, but also indirectly on or below it through intermediate elements. The terms "first," "second," etc., are used for descriptive purposes only and do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0018] The term "comprising" and its variations as used in this invention are open-ended, meaning "including but not limited to". The term "based on" means "at least partially based on". The term "one embodiment" means "at least one embodiment".

[0019] It should be noted that the concepts of "first" and "second" mentioned in this invention are only used to distinguish the corresponding contents and are not used to limit the order or interdependence.

[0020] It should be noted that the terms "a" and "a plurality of" used in this invention are illustrative rather than restrictive. Those skilled in the art should understand that, unless otherwise expressly indicated in the context, they should be understood as "one or more".

[0021] Figure 1 This is a schematic diagram of a fixed-focus lens provided in Embodiment 1 of the present invention, for reference. Figure 1 The fixed-focus lens includes a first lens 11, a second lens 12, a third lens 13, a fourth lens 14, a fifth lens 15, a sixth lens 16, and a seventh lens 17 arranged sequentially along the optical axis from the object plane to the image plane; the first lens 11, the second lens 12, and the sixth lens 16 have negative optical power, and the third lens 13, the fourth lens 14, the fifth lens 15, and the seventh lens 17 have positive optical power; some of the lenses from the first lens 11 to the seventh lens 17 satisfy the following conditions: -0.291 < φ1 / φ < -0.241; 0.463 < φ3 / φ < 0.544; 0.421 < φ5 / φ < 0.491; -0.999 < φ6 / φ < -0.922; 0.425 < φ7 / φ < 0.474; Among them, φ1, φ3, φ5, φ6, φ7, and φ represent the optical power of the first lens 11, the third lens 13, the fifth lens 15, the sixth lens 16, the seventh lens 17, and the entire fixed-focus lens, respectively.

[0022] The optical power of a lens is equal to the difference between the convergence of the image-side beam and the convergence of the object-side beam, characterizing the optical system's ability to deflect light. A larger absolute value of the optical power indicates a stronger ability to bend light, while a smaller absolute value indicates a weaker ability. When the optical power is positive, the refraction of light is converging; when the optical power is negative, the refraction of light is diverging. In this embodiment, all lenses can be housed in a single lens barrel (…). Figure 1 (Not shown in the image) The first lens 11, the second lens 12 and the sixth lens 16 are provided with negative optical power, while the third lens 13, the fourth lens 14, the fifth lens 15 and the seventh lens 17 are provided with positive optical power, so that light can be converged or diverged by each lens.

[0023] Furthermore, setting the first lens 11, third lens 13, fifth lens 15, sixth lens 16, and seventh lens 17 to satisfy the aforementioned proportional relationship between the optical power of each lens and the overall optical power of the lens essentially defines the specific role of the first lens 11, third lens 13, fifth lens 15, sixth lens 16, and seventh lens 17 in the entire optical system of the lens. These five lenses can be used to converge or diverge light. In other words, by reasonably setting the positive and negative values ​​and specific ranges of the optical power of each lens, the relative beam converging or diverging effects of each lens in the entire lens are effectively limited. The aforementioned ratio of the optical power of each lens to the overall optical power of the lens is a proportional relationship obtained through reasonable experiments. Under this optical power ratio, the entire lens can achieve a large image plane and wide-angle imaging performance, while also facilitating the correction and balancing of aberrations such as distortion and axial chromatic aberration. In particular, it can effectively reduce the influence of distortion and ensure the imaging quality of the large image plane.

[0024] The above technical solution, by setting a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, and a seventh lens arranged sequentially along the optical axis from the object side to the image side; the first lens, the second lens, and the sixth lens have negative optical power, while the third lens, the fourth lens, the fifth lens, and the seventh lens have positive optical power; and by limiting the optical power of the first lens, the third lens, the fifth lens, the sixth lens, the seventh lens, and the entire fixed-focus lens to meet a certain proportional range, optical distortion can be controlled to be less than 3%, and the diagonal field of view can be controlled between 80 and 100°, ultimately achieving a lens solution with a large image plane, wide angle, and small distortion.

[0025] In this embodiment, specifically, the object plane side of the first lens 11 is convex, and the image plane side is concave; the image plane side of the second lens 12 is concave; the image plane side of the third lens 13 is convex; the object plane side of the fourth lens 14 is convex, and the image plane side is convex; the object plane side of the fifth lens 15 is convex, and the image plane side is convex; the object plane side of the sixth lens 16 is concave, and the image plane side is concave; and the object plane side of the seventh lens 17 is convex, and the image plane side is convex. By defining the curvature direction of each lens surface, the target optical power of the lens can be achieved, which is beneficial for achieving a proportional match of the optical power of each lens.

[0026] Optionally, the opposing surfaces of the fifth lens 15 and the sixth lens 16 are cemented together to form a cemented lens assembly. Those skilled in the art will understand that the fifth lens 15 and the sixth lens 16 are biconvex and biconcave lenses, respectively. Based on this, by reasonably modifying the surface shapes of the fifth lens 15 and the sixth lens 16, such as the radius of curvature, the curvature of their adjacent surfaces can be made consistent before cementing. This ensures that the fifth lens 15 and the sixth lens 16 can achieve a match in positive and negative optical power, which is beneficial for correcting aberrations such as chromatic aberration.

[0027] Optionally, some of the lenses from the first lens 11 to the seventh lens 17 satisfy the following conditions: 1.60 <ND1<1.65; 1.61 <ND5<1.66; 1.74 <ND6<1.80; 1.51 <ND7<1.58; Among them, ND1, ND5, ND6, and ND7 are the refractive indices of the first lens 11, the fifth lens 15, the sixth lens 16, and the seventh lens 17, respectively.

[0028] Alternatively, some of the lenses from the first lens 11 to the seventh lens 17 may satisfy the following condition: 50.1 <VD1<72.3; 46.8 <VD2<66.7; 49.7 <VD5<66.8; 54.8 <VD7<70.3; Among them, VD1, VD2, VD5, and VD7 are the Abbe constants of the first lens 11, the second lens 12, the fifth lens 15, and the seventh lens 17, respectively.

[0029] Wherein, the refractive index represents the refraction ability of the lens to incident light. A higher refractive index of the material means a stronger refraction ability to incident light. The Abbe number is an index representing the dispersion ability of a medium, and a larger Abbe number indicates slighter dispersion. The adoption of the above combination is beneficial for effectively correcting the axial chromatic aberration and lateral chromatic aberration of the entire lens, thereby obtaining higher resolution and better imaging performance.

[0030] In addition, for the fourth lens 14, the following condition may alternatively be satisfied: 1.72 < ND4 < 1.77, wherein ND4 is the refractive index of the fourth lens 14. Limiting the refractive index of the fourth lens 14 within the range of 1.72 to 1.77 can reduce the lens sensitivity, allow the light passing through the fourth lens 14 to transition smoothly, help reduce the incident angle of light, and also contribute to correcting chromatic aberration and spherical aberration.

[0031] Alternatively, the fixed-focus lens satisfies the following condition: 0.308 < BFL / ImgH < 0.532, wherein BFL represents the distance from the image-side surface of the seventh lens 17 to the imaging surface, and ImgH is the diagonal length of the effective imaging area on the imaging surface. In this case, the fixed-focus lens can ensure a large image surface while maintaining a sufficiently long back focal length, thereby helping provide sufficient installation space for the flat filter and facilitating assembly.

[0032] More specifically, the second lens 12 and the seventh lens 17 are aspheric plastic lenses, and the first lens 11, the third lens 13, the fourth lens 14, the fifth lens 15, and the sixth lens 16 are spherical glass lenses.

[0033] Wherein, configuring the second lens 12 and the seventh lens 17 as aspheric lenses mainly utilizes the aspheric structure to correct aberrations of the second lens 12 and the seventh lens 17 which are prone to produce obvious aberrations, and configuring the second lens 12 and the seventh lens 17 to be made of plastic is more for the consideration that compared with other materials, aspheric plastic lenses have relatively lower manufacturing difficulty, which can save manufacturing costs to a certain extent.

[0034] In addition, configuring all other lenses except the second lens 12 and the seventh lens 17 to be made of glass, whose main purpose is to use glass material to reduce the temperature sensitivity of the lenses, ensure the imaging quality of the lenses under different temperatures, meet the use requirements under the temperature condition of -40°C to 95°C, and is more suitable for the use requirements of different application scenarios such as indoor and outdoor.

[0035] Based on the same inventive concept, an embodiment of the present invention further provides a video communication imaging apparatus, and the video communication imaging apparatus includes any one of the fixed-focus lenses provided in the above embodiments. And since the video communication imaging apparatus includes the fixed-focus lens of the above embodiments, it has the same or similar beneficial effects as the fixed-focus lens, which will not be repeated herein.

[0036] Based on the same inventive concept, this invention provides three different specific embodiments, the optical power relationship and related physical and optical parameter design ranges of which are shown in Table 1: Table 1. Relationships of optical power and design ranges of related physical and optical parameters for fixed-focus lenses in three embodiments of the present invention. like Figure 1 The parameter design values ​​of each lens in the fixed-focus lens of Embodiment 1 are shown in Table 2: Table 2 shows a design value for each lens in the fixed-focus lens in Example 1. The surface numbers in Table 2 are assigned according to the surface sequence of each lens. "S1" represents the front surface of the first lens, "S2" represents the rear surface of the first lens, and so on. The radius of curvature represents the curvature of the lens surface. A positive value indicates that the surface bends towards the image plane, and a negative value indicates that the surface bends towards the object plane. "PL" indicates that the surface is flat and the radius of curvature is infinite. The thickness represents the central axial distance between the current surface and the next surface. The refractive index represents the ability of the material between the current surface and the next surface to deflect light. A blank space indicates that the current position is air and the refractive index is 1. The Abbe number represents the dispersion characteristics of the material between the current surface and the next surface. A blank space indicates that the current position is air. The K value represents the value of the best-fit conic coefficient of the aspherical surface.

[0037] The conicity coefficients of aspherical surfaces can be defined using the following aspherical formulas, but are not limited to the following representations: ; Where z is the axial sagitta in the Z-direction of the aspherical surface; r is the height of the aspherical surface; c is the curvature of the fitted sphere, numerically the reciprocal of the radius of curvature; k is the fitted conic coefficient; a n These are the coefficients of the 2n-th order terms of the aspherical polynomial.

[0038] The coefficients of even-order terms for each aspherical surface in the above embodiment 1 are shown in Table 3: Table 3 Parameters of each aspherical surface Table 4 shows the technical specifications of the fixed-focus lens in this embodiment: Figure 2 yes Figure 1 The spherical aberration curve of the fixed-focus lens in Embodiment 1 is shown below. Figure 3 yes Figure 1 The field curvature distortion diagram of the fixed-focus lens in Embodiment 1 is shown. Figure 2The vertical axis is dimensionless, representing the normalized entrance pupil radius, while the horizontal axis represents the distance from the image sensor surface to the focal point on each wavelength axis. The spherical aberration curve shows that the horizontal axis values ​​for all wavelengths are within ±0.1 mm, indicating that the optical system has good axial chromatic aberration correction. Figure 3 In the left-hand coordinate system, the horizontal coordinate represents the magnitude of the field curvature in mm; the vertical coordinate represents the normalized image height, which has no unit; where T represents the meridion and S represents the arc loss; from Figure 3 It can be seen that the fixed-focus lens in this embodiment effectively controls field curvature, meaning that during imaging, the difference in image quality between the center and the periphery is small; in the coordinate system on the right, the horizontal axis represents the magnitude of distortion, expressed as a percentage; the vertical axis represents the normalized image height, which has no unit; from Figure 3 It can be seen that the substrate of the fixed-focus lens in this embodiment satisfies: -3%≤distortion≤0.

[0039] Figure 4 This is a schematic diagram of a fixed-focus lens provided in Embodiment 2 of the present invention. Figure 4 The optical power relationship and related physical and optical parameter design ranges of the fixed-focus lens in Embodiment 2 are shown in Table 1. The design values ​​of one parameter for each lens in this fixed-focus lens are shown in Table 5. Table 5 shows a design value for each lens in the fixed-focus lens in Example 2. The surface numbers in Table 5 are assigned according to the surface sequence of each lens. "S1" represents the front surface of the first lens, "S2" represents the rear surface of the first lens, and so on. The radius of curvature represents the curvature of the lens surface. A positive value indicates that the surface bends towards the image plane, and a negative value indicates that the surface bends towards the object plane. "PL" indicates that the surface is flat and the radius of curvature is infinite. The thickness represents the central axial distance between the current surface and the next surface. The refractive index represents the ability of the material between the current surface and the next surface to deflect light. A blank space indicates that the current position is air and the refractive index is 1. The Abbe number represents the dispersion characteristics of the material between the current surface and the next surface. A blank space indicates that the current position is air. The K value represents the value of the best-fit conic coefficient of the aspherical surface.

[0040] The conicity coefficients of aspherical surfaces can be defined using the following aspherical formulas, but are not limited to the following representations: ; Where z is the axial sagitta in the Z-direction of the aspherical surface; r is the height of the aspherical surface; c is the curvature of the fitted sphere, numerically the reciprocal of the radius of curvature; k is the fitted conic coefficient; a n These are the coefficients of the 2n-th order terms of the aspherical polynomial.

[0041] The even-order coefficients of each aspherical surface in the above embodiment 2 are shown in Table 6: Table 6 Parameters of Aspherical Surfaces Table 7 shows the technical specifications of the fixed-focus lens in this embodiment two: Figure 5 yes Figure 4 The spherical aberration curve of the fixed-focus lens in Embodiment 2 is shown below. Figure 6 yes Figure 4 The field curvature distortion diagram of the fixed-focus lens in Embodiment 2 is shown. Figure 5 The vertical axis is dimensionless, representing the normalized entrance pupil radius, while the horizontal axis represents the distance from the image sensor surface to the focal point on each wavelength axis. The spherical aberration curve shows that the horizontal axis values ​​for all wavelengths are within ±0.1 mm, indicating that the optical system has good axial chromatic aberration correction. Figure 6 In the left-hand coordinate system, the horizontal coordinate represents the magnitude of the field curvature in mm; the vertical coordinate represents the normalized image height, which has no unit; where T represents the meridion and S represents the arc loss; from Figure 6 It can be seen that the fixed-focus lens in this embodiment effectively controls field curvature, meaning that during imaging, the difference in image quality between the center and the periphery is small; in the coordinate system on the right, the horizontal axis represents the magnitude of distortion, expressed as a percentage; the vertical axis represents the normalized image height, which has no unit; from Figure 6 It can be seen that the substrate of the fixed-focus lens in this embodiment two satisfies: -3%≤distortion≤0.

[0042] Note that the above description is merely a preferred embodiment of the present invention and the technical principles employed. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and various obvious changes, readjustments, combinations, and substitutions can be made without departing from the scope of protection of the present invention. Therefore, although the present invention has been described in detail through the above embodiments, the present invention is not limited to the above embodiments, and may include many other equivalent embodiments without departing from the concept of the present invention, the scope of which is determined by the scope of the appended claims.

Claims

1. A fixed-focus lens, characterized in that, It includes a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, and a seventh lens arranged sequentially along the optical axis from the object plane to the image plane; The first lens, the second lens, and the sixth lens have negative optical power, while the third lens, the fourth lens, the fifth lens, and the seventh lens have positive optical power. The fixed-focus lens has 7 lenses with optical power. The opposing surfaces of the fifth lens and the sixth lens are cemented together to form a cemented lens group, and the fixed-focus lens has one cemented lens group. The first lens, the third lens, the fifth lens, the sixth lens, and the seventh lens satisfy the following conditions: -0.291 < φ1 / φ < -0.241; 0.463 < φ3 / φ < 0.544; 0.421 < φ5 / φ < 0.491; -0.999 < φ6 / φ < -0.922; 0.425 < φ7 / φ < 0.474; Wherein, φ1 is the optical power of the first lens, φ3 is the optical power of the third lens, φ5 is the optical power of the fifth lens, φ6 is the optical power of the sixth lens, φ7 is the optical power of the seventh lens, and φ is the optical power of the fixed-focus lens.

2. The fixed-focus lens according to claim 1, characterized in that: The object plane side of the first lens is convex, and the image plane side is concave. The image plane side of the second lens is concave; The image plane side of the third lens is convex; The object plane side of the fourth lens is convex, and the image plane side is also convex. The object plane side of the fifth lens is convex, and the image plane side is also convex. The object plane side of the sixth lens is concave, and the image plane side is also concave. The object plane side of the seventh lens is convex, and the image plane side is also convex.

3. The fixed-focus lens according to claim 1, characterized in that, The first lens, the fifth lens, the sixth lens, and the seventh lens satisfy the following conditions: 1.60 <ND1<1.65; 1.61 <ND5<1.66; 1.74 <ND6<1.80; 1.51 <ND7<1.58; Wherein, ND1 is the refractive index of the first lens, ND5 is the refractive index of the fifth lens, ND6 is the refractive index of the sixth lens, and ND7 is the refractive index of the seventh lens.

4. The fixed-focus lens according to claim 1, characterized in that, The first lens, the second lens, the fifth lens, and the seventh lens satisfy the following conditions: 50.1 <VD1<72.3; 46.8 <VD2<66.7; 49.7 <VD5<66.8; 54.8 <VD7<70.3; Wherein, VD1 is the Abbe constant of the first lens, VD2 is the Abbe constant of the second lens, VD5 is the Abbe constant of the fifth lens, and VD7 is the Abbe constant of the seventh lens.

5. The fixed-focus lens according to claim 1, characterized in that, The fourth lens satisfies the following condition: 1.72 <ND4<1.77; Wherein, ND4 is the refractive index of the fourth lens.

6. The fixed-focus lens according to claim 1, characterized in that, The second lens and the seventh lens are aspherical plastic lenses, while the first lens, the third lens, the fourth lens, the fifth lens, and the sixth lens are spherical glass lenses.

7. The fixed-focus lens according to claim 1, characterized in that, The fixed-focus lens satisfies the following condition: 0.308 <BFL / ImgH<0.532; Wherein, BFL represents the distance from the image-side surface of the seventh lens to the imaging surface, and ImgH is the diagonal length of the effective imaging area on the imaging surface.

8. A video communication imaging device, characterized in that, Including the fixed-focus lens as described in any one of claims 1-7.

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