A TOF camera module and electronic equipment

Abstract

The present application relates to a time-of-flight TOF camera module and electronic equipment. The camera module includes a circuit board and a transmitting module and a receiving module arranged on the upper surface of the circuit board. The transmitting module includes a light source for transmitting N beams of point light and a projection lens for collimating and projecting the N beams of point light. The receiving module is used to receive N returned depth light signals and convert them into electrical signals. The field of view FOV of the projection lens satisfies 65°<FOV<80°, the F number of the projection lens is less than 1.9, and the focal length is 1.2<f<1.4. Through the design of the projection lens, the N beams of point light emitted by the light source pass through the projection lens and are directly projected onto the target object with a predetermined field of view and intensity without copying the light signal and setting a light signal copying element, which saves costs, reduces the thickness of the entire camera module, and reduces the difficulty of assembling the camera module. Since the N beams of point light directly reach the target object after passing through the projection lens, the loss of light is reduced and the utilization rate of the light source is improved.

Description

Technical Field

[0001] The present application relates to the technical field of electronic products, and in particular to a time-of-flight TOF camera module and electronic equipment. Background Art

[0002] Time of Flight (TOF) camera module is a commonly used depth camera module that can be used to measure depth of field (depth) or distance information, and can realize the three-dimensional imaging or distance detection function of the electronic device to the target object. The TOF camera module generally includes an optical signal transmission (Tx) module and an optical signal receiving (Rx) module. The optical signal transmission module of the existing TOF camera module usually includes a transmitter chip, a collimator lens (collimator lens) and a diffractive projection lens (Diffractive Optical Elements, DOE). DOE is used to replicate the light beam emitted by the transmitter chip in a certain multiple and transmit it outward into a speckle light signal in multiple areas, so as to expand the measurement range of the TOF camera module and improve the measurement accuracy of the depth measurement. However, the structure of the existing TOF is relatively complex, the assembly is difficult, and the cost is high. Summary of the invention

[0003] The present application provides a time-of-flight TOF camera module and electronic equipment, which are used to simplify the structure of the camera module, reduce processing difficulty, and reduce costs.

[0004] The embodiment of the present application provides a time-of-flight TOF camera module, which is used to project a speckle light array consisting of N speckles to a target object at a target field of view angle, and the camera module includes:

[0005] A circuit board, the upper surface of which includes at least a first area and a second area that do not overlap each other;

[0006] an emission module, which is arranged in the first area of ​​the circuit board, the emission module comprises a light source and a projection lens, the light source is used to emit N beams of spot light, the field of view angle FOV of the projection lens satisfies: 65°<FOV<80°, the F number of the projection lens is less than 1.9, the focal length is 1.2<f<1.4, and the projection lens is used to collimate the N beams of spot light and project the N beams of spot light onto the target object to generate a speckle light array consisting of the N speckles on the target object; and

[0007] A receiving module is arranged in the second area of ​​the circuit board, and is used for receiving the depth light signal returned after the N speckle arrays irradiate the target object and for converting the depth light signal into an electrical signal.

[0008] In a possible implementation, the projection lens satisfies: 0.1 < |Y / (f * TTL)| < 0.4, where f is the focal length of the projection lens, Y is the maximum object height of the projection lens, and TTL is the distance between the diaphragm plane and the imaging plane of the projection lens.

[0009] In a possible implementation, the projection lens satisfies: 0.3 < f / TTL < 0.5, where f is the focal length of the projection lens, and TTL is the distance between the diaphragm plane and the imaging plane of the projection lens.

[0010] In a possible implementation, the projection lens satisfies: 0.2 < Y / TTL < 0.4, where Y is the maximum object height of the projection lens, and TTL is the distance between the diaphragm plane and the imaging plane of the projection lens.

[0011] In a possible implementation, the field of view FOV of the projection lens is 71.9°.

[0012] In a possible implementation, the F-number of the projection lens is equal to 1.76.

[0013] In a possible implementation, a diaphragm and a lens group are sequentially arranged on the projection lens along the imaging side to the light source side, and the lens group includes at least two lenses.

[0014] In a possible implementation, the lens group includes a first lens, a second lens, and a third lens sequentially arranged along the imaging side to the light source side;

[0015] The first lens is a lens with positive optical power. The first lens is concave on the imaging side in the paraxial region and convex on the light source side in the paraxial region. At least one of the two surfaces of the first lens is an aspherical surface;

[0016] The second lens is a lens with negative optical power. The second lens is concave on the imaging side in the paraxial region and convex on the light source side in the paraxial region, and at least one of the two surfaces of the second lens is an aspherical surface;

[0017] The third lens is a lens with positive optical power. The third lens is convex on the imaging side in the paraxial region, and at least one of the two surfaces of the third lens is an aspherical surface.

[0018] In a possible implementation, the camera module includes a first lens barrel and a second lens barrel, and the receiving module includes an image sensor chip, an imaging lens, and a filter;

[0019] The first lens barrel is installed in the first area of the circuit board, and the projection lens is fixed to the first lens barrel and arranged above the light source;

[0020] The second lens barrel is installed in the second area of ​​the circuit board, the image sensor chip is accommodated in the second lens barrel, the imaging lens is fixed in the second lens barrel and arranged above the image sensor chip, and is used to image the depth light signal to the image sensor chip, and the filter is located between the imaging lens and the image sensor chip.

[0021] In a possible implementation, the camera module further includes a ceramic substrate, the light source is disposed on a prime circuit board through the ceramic substrate, and a projection area of ​​the ceramic substrate on an upper surface of the circuit board is smaller than an area of ​​the upper surface.

[0022] In a possible implementation manner, the first lens barrel is mounted on the circuit board through the ceramic substrate.

[0023] In a possible implementation, the camera module further includes a driver, which is mounted on the circuit board and is used to drive the light source to emit light.

[0024] In a possible implementation manner, the driving component is mounted on the circuit board through a ceramic substrate, and the driving component and the light source are located on the same side of the ceramic substrate.

[0025] In a possible implementation, the circuit board has a lower surface opposite to the upper surface, the lower surface is provided with a recessed portion recessed toward the upper surface, and at least a portion of the driving member is located in the recessed portion.

[0026] In a possible implementation manner, a reinforcing plate is provided on the lower surface of the circuit board.

[0027] The present application also provides an electronic device, comprising:

[0028] A time-of-flight TOF camera module as described in any of the above items, wherein the time-of-flight TOF camera module is used to measure depth information of a target object;

[0029] A control unit is used to perform operation control on at least one function of the electronic device according to the depth information.

[0030] The present application relates to a time-of-flight TOF camera module and electronic equipment. The camera module includes a circuit board and a transmitting module and a receiving module arranged on the upper surface of the circuit board. The transmitting module includes a light source for emitting N beams of point light and a projection lens for collimating and projecting the N beams of point light. The receiving module is used to receive N returned depth light signals and convert them into electrical signals. Among them, the field of view FOV of the projection lens satisfies 65°<FOV<80°, the F number of the projection lens is less than 1.9, and the focal length is 1.2<f<1.4. Through the design of the projection lens, the N beams of point light emitted by the light source pass through the projection lens and are directly projected onto the target object with a predetermined field of view and intensity without copying the light signal and setting up a light signal copying element, which saves costs, reduces the thickness of the entire camera module, and reduces the difficulty of assembling the camera module. Furthermore, since the N beams of point light directly reach the target object after passing through the projection lens, the loss of light is reduced, and the utilization rate of the light source is greatly improved.

[0031] It should be understood that the foregoing general description and the following detailed description are exemplary only and are not restrictive of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 A schematic diagram of the structure of the camera module provided in this application;

[0033] Figure 2 A schematic diagram of the internal structure of the first embodiment of the camera module provided in this application;

[0034] Figure 3 A schematic diagram of a projection lens provided in this application;

[0035] Figure 4 A schematic diagram of the internal structure of the second embodiment of the camera module provided in this application;

[0036] Figure 5 A schematic diagram of the internal structure of the third embodiment of the camera module provided in this application;

[0037] Figure 6 This is a schematic diagram of the structure of the circuit board and reinforcement board provided in this application.

[0038] Reference numerals:

[0039] 1- Transmitter module;

[0040] 11- Light source;

[0041] 12- Projection lens;

[0042] 121- aperture;

[0043] 122-first lens;

[0044] 123- second lens;

[0045] 124- third lens;

[0046] 13- first lens barrel;

[0047] 2- receiving module;

[0048] 21- second lens barrel;

[0049] 22- Image sensor chip;

[0050] 23- Imaging lens;

[0051] 24- filter;

[0052] 3- Circuit board;

[0053] 31-depression;

[0054] 4- Ceramic substrate;

[0055] 5- driving member;

[0056] 6-Reinforcement plate.

[0057] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application. DETAILED DESCRIPTION

[0058] In order to better understand the technical solution of the present application, the embodiments of the present application are described in detail below with reference to the accompanying drawings.

[0059] It should be clear that the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present application.

[0060] The terms used in the embodiments of the present application are only for the purpose of describing specific embodiments, and are not intended to limit the present application. The singular forms "a", "said" and "the" used in the embodiments of the present application and the appended claims are also intended to include plural forms, unless the context clearly indicates other meanings.

[0061] It should be understood that the term "and / or" used in this article is only a description of the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0062] It should be noted that the directional words such as "upper", "lower", "left", and "right" described in the embodiments of the present application are described at the angles shown in the accompanying drawings and should not be understood as limiting the embodiments of the present application. In addition, in the context, it is also necessary to understand that when it is mentioned that an element is connected to another element "upper" or "lower", it can not only be directly connected to another element "upper" or "lower", but also indirectly connected to another element "upper" or "lower" through an intermediate element.

[0063] like Figure 1 and Figure 2 As shown, the embodiment of the present application provides a time-of-flight TOF camera module, the camera module includes a circuit board 3, a transmitting module 1 and a receiving module 2, the circuit board 3 has an upper surface and a lower surface arranged along its thickness direction, wherein the upper surface is provided with a first area and a second area which do not overlap each other, the transmitting module 1 is arranged in the first area, the transmitting module 1 includes a light source 11 and a projection lens 12, the light source 11 is used to emit N beams of point light, and the specific value of N can be set according to actual needs. The projection lens 12 is used to process the light signal emitted by the light source 11 into a speckle light signal. Among them, the light source 11 can be a light source 11 such as a vertical cavity surface emitting laser (VCSEL), a light emitting diode (LED), or an array composed of multiple light sources 11, and the light source 11 can be a single-chip multi-point emitting VCSEL chip, and multiple light emitting points are arranged in a two-dimensional matrix, and correspondingly emit multiple laser signals to form a matrix light signal array. The projection lens 12 is used to collimate N spot lights and transmit the N spot lights to the target object, generating a speckle light array composed of N speckles on the target object. The receiving module 2 is arranged in the second area of ​​the circuit board 3, and is used to receive the depth light signal returned after the N speckle light arrays are irradiated to the target object and to convert the depth light signal into an electrical signal. Among them, the field of view (FOV) of the projection lens 12 satisfies: 65°<FOV<80°, and the F number of the projection lens is less than 1.9, and the focal length is 1.2<f<1.4.

[0064] Field of View (FOV): It is used to characterize the field of view of a lens. When the lens sizes are equal, the larger the FOV of the lens, the larger the projection field of view of the lens.

[0065] Distortion: It is used to measure the degree of visual distortion of an image. The smaller the distortion, the better the imaging effect.

[0066] Relative Illumination (RI): refers to the ratio of the illumination at different coordinate points on the imaging surface to the illumination at the center point. The smaller the relative illumination, the more uneven the illumination on the imaging surface, which is prone to underexposure in some locations or overexposure in the center, affecting the imaging quality. The larger the relative illumination, the higher the imaging quality.

[0067] Working F number, or F number (F-number, Fno): It is the reciprocal of the relative diameter of the lens, which is used to characterize the amount of light that enters the photosensitive chip through the lens. The smaller the F number, the more light enters the lens.

[0068] Generally, the existing TOF module can change the diameter and divergence angle of the light beam in the dimming system through the collimating lens, so that the light beam becomes a collimated parallel light beam, so that the energy of the light beam is more concentrated, so that a small high-power density light spot can be obtained. When it is necessary to obtain a speckle light signal, a light copying element will be further added above the collimating lens to copy the collimated light signal to obtain a speckle light signal. Optionally, the light signal copying element can be a combination of at least one or more optical elements in a diffractive optical element (DOE), a micro lens array (MLA), a grating or any other optical element that can form spot light. DOE is usually made of glass or plastic, and is used to copy the light beam emitted by the light source at a certain multiple and then project it outward into a speckle light signal in multiple regions. Taking DOE as an example, the light signal is copied by DOE to increase the number of light signals, thereby meeting the demand of the receiving module 2 for the number of light signals to improve the accuracy of the measurement. For example, the array optical signal emitted by the transmitter chip includes n optical signals, and the replication multiple of DOE is m. After being replicated by DOE, n*m optical signals are formed, and the receiving module 2 can receive n*m ​​optical signals returned from the target object, thereby improving the accuracy of measurement. However, when the light passes through the DOE, more than 10% of energy loss will be generated. The optical efficiency of the existing transmitting module 1 including the collimating lens and the diffractive optical element is usually 56%, and the F number is 2.83. Due to the low transmittance of the light, it is necessary to increase the power of the TOF module. The single-hole optical power requirement is usually 100mW. Usually, a boost circuit (boost circuit) needs to be set, and the safety of the TOF module will decrease with the increase of power. When the TOF module is damaged, the light emitted by the transmitter chip is directly irradiated and easily causes harm to the human body. Therefore, an indium tin oxide (ITO) protection circuit needs to be set. The protection circuit needs to include components such as metal shrapnel as positive and negative electrodes, resulting in an increase in the number of components of the TOF module as a whole, a complex structure, a greater difficulty in assembly, and a higher material cost.

[0069] Compared with the existing method of processing the optical signal into a collimated optical signal, the solution provided in the embodiment of the present application can process the optical signal emitted by the light source 11 through the projection lens 12 so that the optical signal forms a speckle light array, which can increase the irradiation range of a single optical signal to a certain extent, so that the processed optical signal can meet the use requirements, thereby eliminating the optical signal replication element, and thus reducing the loss of the optical signal during propagation, which is beneficial to improving the optical efficiency, and the optical efficiency can reach 80%. Due to the high optical efficiency, the single-hole optical power can be reduced, usually to 7mW, so the boost circuit can be omitted, and the structure of the TOF module is simplified. At the same time, due to the reduction of the single-hole optical power, the safety of the TOF module is also improved, and the protection circuit and related components of the protection circuit can be omitted. While simplifying the TOF module structure, it can also reduce the difficulty of assembly, and the cost of materials can be reduced to better meet actual use requirements.

[0070] Through the design of the projection lens 12, the N beams of point light emitted by the light source 11 are directly projected onto the target object at a predetermined field angle and intensity after passing through the projection lens 12, without the need to copy the light signal or set up a light signal copying element, thus saving costs, reducing the thickness of the entire camera module, and reducing the difficulty of assembling the camera module. Since the N beams of point light directly reach the target object after passing through the projection lens 12, light loss is reduced and the utilization rate of the light source 11 is improved.

[0071] The transmitting module 1 and the receiving module 2 share a circuit board 3 and are arranged on the same surface. During installation, they can refer to a common reference point or each other, which is beneficial to reducing the alignment tolerance between the transmitting module 1 and the receiving module 2, and can reduce the relative optical axis angle between the optical axis of the transmitting module 1 and the receiving module 2, which can enhance the imaging function or distance detection function of the camera module, and at the same time can reduce the cost of the circuit board 3. The transmitting module 1 and the receiving module 2 no longer require a metal bracket during the assembly process, which is not only beneficial to reducing the bracket cost of the camera module, but also can save the assembly process of the additional metal bracket, which is beneficial to reducing the assembly process cost of the camera module.

[0072] In a possible implementation, the projection lens 12 can have a larger field of view FOV and a smaller F number by designing various parameters of the projection lens 12. f is the focal length of the projection lens 12, Y is the maximum image height on the image plane of the camera module, and TTL is the distance between the aperture 121 and the light source 11. For example, f, Y and TTL can satisfy 0.1<|Y / (f*TTL)|<0.4.

[0073] The f, Y, and TTL of the projection lens 12 affect the FOV and F-number of the projection lens. There are also mutual restrictions and influences among f, Y, and TTL. Therefore, by controlling the three parameters of f, Y, and TTL to meet the above preset conditions, the projection lens 12 can obtain a larger wide-angle field of view, detect a larger range, and enable the projection lens 12 to have a smaller F-number so as to collect more light and improve the performance of the lens.

[0074] When the relationship among the f, Y, and TTL of the projection lens satisfies 0.1 < |Y / (f * TTL)| < 0.4, the FOV of the projection lens 12 satisfies 60° < FOV < 85°. Further, the FOV of the projection lens 12 can also satisfy 65° < FOV < 85°, 65° < FOV ≤ 80°, 65° < FOV ≤ 75°, or 65° < FOV ≤ 70°, etc., so as to achieve the balance between the accuracy requirement and the field-of-view requirement of depth detection. When the relationship among the f, Y, and TTL of the projection lens 12 satisfies 0.1 < |Y / (f * TTL)| < 0.4, the F-number of the projection lens 12 is less than 1.9. Further, the F-number of the projection lens 12 can also satisfy: the F-number is less than 1.8, etc., so that the projection lens 12 can collect more light.

[0075] It should be understood that the above preset conditions are the conditions that the f, Y, and TTL of the projection lens 12 should meet when designing the projection lens 12, so as to improve the projection performance of the projection lens 12 while ensuring the required FOV and F-number. In some cases, in order to obtain better projection performance, the preset conditions can be appropriately adjusted. For example, the preset conditions can be adjusted to: 0.1 < |Y / (f * TTL)| < 0.30, 0.2 < |Y / (f * TTL)| < 0.30, 0.1 < |Y / (f * TTL)| < 0.25, 0.15 < |Y / (f * TTL)| < 0.30, or 0.15 < |Y / (f * TTL)| < 0.25, etc.

[0076] In a possible implementation manner, the f, Y, and TTL of the projection lens 12 can also satisfy at least one of 0.3 < f / TTL < 0.5 and 0.2 < Y / TTL < 0.4.

[0077] By further restricting the parameters of the projection lens 12, the FOV of the projection lens 12 can be made as large as possible within the above range, and the F-number of the projection lens can be made as small as possible within the above range. The above preset conditions can also be further adjusted to: 0.3 < f / TTL < 0.46, 0.4 < f / TTL < 0.46, 0.2 < Y / TTL < 0.35, 0.25 < Y / TTL < 0.35, or 0.2 < Y / TTL < 0.3, etc.

[0078] In a possible implementation, by restricting the above parameters, the parameters of the projection lens 12 can meet the following conditions: FOV = 71.9°, and the F-number is equal to 1.76.

[0079] The camera module provided by the embodiments of the present application has a small F-number and a large field of view FOV, which can improve the optical efficiency of the camera module and the light transmittance. The transmittance of the existing TOF module (including DOE) is usually 56%, while the transmittance of the camera module provided by the embodiments of the present application can reach 80%.

[0080] In a possible implementation, the projection lens 12 includes a diaphragm 121 and a lens group. The lens group includes at least two lenses. By adjusting the structure and parameters of the lens group, the parameters of the projection lens 12 can meet the foregoing conditions.

[0081] As Figure 3 shown, in a possible implementation, the projection lens 12 is sequentially provided with a diaphragm 121, a first lens 122, a second lens 123, and a third lens 124 from the imaging side (projection target side) to the light source side. The first lens 122 is a positive refractive power lens. The first lens 122 is convex on the near-axis light source side, and at least one of the two surfaces of the first lens 122 is an aspherical surface. The second lens 123 is a negative refractive power lens. The second lens 123 is concave on the near-axis imaging side and convex on the near-axis light source side, and at least one of the two surfaces of the second lens 123 is an aspherical surface. The third lens 124 is a positive refractive power lens. The third lens 124 is convex on the near-axis imaging side, and at least one of the two surfaces of the third lens 124 is an aspherical surface.

[0082] The first lens 122 is a positive refractive power lens with a focal length of f1. The positive refractive power distribution of the first lens 122 can expand the angle when the light exits, and can increase the field of view FOV. The near-axis curvature radius of the imaging side surface of the first lens 122 is R1, and the near-axis curvature radius of the light source side surface is R2. The first lens 122 can meet the following conditions: -1 < f1 / R1 < -0.2; -2.5 < f1 / R2 < -1.5; 2 < R1 / R2 < 4.5. Through the above conditions, the curvature radii of the two surfaces of the first lens 122 can be reasonably distributed, which helps to correct aberration when deflecting light rays.

[0083] The second lens 123 is a negative-power lens with a focal length of f2. The negative-power distribution of the second lens 123 can effectively correct aberrations and improve the quality of projection. The paraxial curvature radius of the image side surface of the second lens 123 is R3, and the paraxial curvature radius of the light source side surface is R4. The second lens 123 can satisfy the following conditions: 2 < f2 / R3 < 4.5; 0.4 < f2 / R4 < 2; 0.25 < R3 / R4 < 0.45. The reasonable distribution of the curvature radii of the two surfaces of the second lens 123 helps the lens to better correct aberrations while contributing negative power.

[0084] The third lens 124 is a positive-power lens with a focal length of f3. The paraxial curvature radius of the image side surface of the third lens 124 is R5, and the paraxial curvature radius of the light source side surface is R6. The third lens 124 satisfies the following conditions: 1.4 < f3 / R5 < 1.6; 0.2 < f3 / R6 < 0.1; -0.2 < R5 / R6 < 0.1.

[0085] The third lens 124 is the lens closest to the light source 11. After the light rays are emitted from the light source 11, the positive-power third lens 124 deflects the light rays first, which can effectively reduce the effective aperture sizes of the first lens 122 and the second lens 123, and at the same time can ensure that the projection lens 12 has a large field of view FOV.

[0086] In addition, since 2 < R1 / R2 < 4.5, 0.2 < R3 / R4 < 0.45, -0.2 < R5 / R6 < 0.1, by designing the curvature radii of the three lenses in the lens 110 respectively, while the FOV and F-number of the lens 110 meet the requirements, the sensitivity of the lens 110 can be reduced and the yield rate of the product can be improved.

[0087] The number of lenses in the lens group can be adjusted. It can be two lenses, or four or more lenses. The parameters of each lens can be adjusted to make the projection lens 12 meet the foregoing preset conditions.

[0088] When the number of lenses is too large, the volume of the transmitting module 1 increases, and the overall volume of the camera module increases. Moreover, the positions of the receiving module 2 and the transmitting module 1 need to be matched with each other. Normally, the receiving module 2 and the transmitting module 1 are approximately at the same height. When the volume and position of the transmitting module 1 change, the position of the receiving module 2 also needs to be adjusted accordingly, which increases the difficulty of the overall design of the camera module. Moreover, due to the increase in the number of lenses, the cost of the projection lens 12 is also relatively high. When the number of lenses is too small, the ability of the lens to process light signals is relatively poor. Normally, four lenses can be arranged inside the receiving module 2. Since the transmitting module 1 is provided with a light source 11, the light source 11 will occupy a certain space. In order to make the heights of the transmitting module 1 and the receiving module 2 approximately the same, the volume of the projection lens 12 can be reduced by reducing the number of lenses of the projection lens 12, thereby reducing the impact on the volume of the transmitting module 1. Considering the comprehensive structure, processing difficulty, cost and other factors, the projection lens 12 with three lenses is a more preferred solution.

[0089] In a possible implementation, the focal length of the projection lens 12 is f, the focal length of the first lens 122 is f1, the focal length of the second lens 123 is f2, the focal length of the third lens 124 is f3, and the distribution of the optical power between the lenses satisfies the following conditions: 0.8 <f1 / f<1.3、-1.3<f2 / f<-0.5、0.4<f3 / f<1.1、-1.3<f2 / f1<-0.5、0.3<f3 / f1<1。

[0090] By designing the focal lengths of the three lenses respectively and reasonably allocating the focal lengths of the first lens 122 , the second lens 123 and the third lens 124 , the projection lens 12 can have a larger FOV range and a smaller F number, while better correcting aberrations, thereby effectively improving the projection quality of the projection lens 12 .

[0091] The radius of curvature satisfies the following conditions: 2 <r1 / r2<4.5、0.25<r3 / r4<0.45、-0.2<r5 / r6<0.1。

[0092] Such a design can reduce the sensitivity of the lens group and improve product yield.

[0093] The thickness of the first lens 122 on the optical axis is CT1, the thickness of the second lens 123 on the optical axis is CT2, and the thickness of the third lens 124 on the optical axis is CT3. The three lenses meet the following conditions: 0.5 <CT1 / CT2<1.5、0.2<CT2 / CT3<1。

[0094] By designing the center thickness of the lens, that is, the thickness of the lens along the optical axis, the lens can have a reasonable thickness, making the projection lens 12 more robust, which is beneficial to improving the service life of the projection lens 12.

[0095] The refractive index of the first lens material is n1, the dispersion coefficient is v1, the refractive index of the second lens is n2, the dispersion coefficient is v2, and the refractive index of the third lens is n3, the dispersion coefficient is v3. And the following conditions are met: n1>1.60, n2>1.60, n2>1.60, v1>22.0, v2>22.0 and v3>22.0.

[0096] By designing the refractive index and dispersion coefficient of the material of each lens, the production cost can be reduced, dispersion can be reduced, and a suitable aberration balance can be provided.

[0097] In a possible implementation manner, the parameters of the projection lens 12 may be adjusted so that the projection lens 12 satisfies: f=1.35 mm, F number=1.78, FOV=72°, and TTL=3.29 mm.

[0098] Specifically, in this embodiment, other parameters of the projection lens 12 satisfy:

[0099] Table 1

[0100]

[0101] Table 3 shows the aspheric high-order coefficients of aspheric lenses: A4, A6, A8, A10, A12, A14, A16:

[0102] Table 2

[0103]

[0104]

[0105] like Figure 2As shown, in a possible implementation, the camera module includes a first lens barrel 13 and a second lens barrel 21, and the receiving module 2 also includes an image sensor chip 22, an imaging lens 23 and a filter 24. The first lens barrel 13 is installed in the first area of ​​the circuit board 3, and the projection lens 12 is fixed to the first lens barrel 13 and installed above the light source 11. The first lens barrel 13 is used to install and protect the projection lens 12. The second lens barrel 21 is installed in the second area of ​​the circuit board 3 and can accommodate the image sensor chip 22, and the imaging lens 23 is fixed in the second lens barrel 21 and is arranged above the image sensor chip 22, and is used to image the depth light signal to the image sensor chip 22. The filter 24 is located between the imaging lens 23 and the image sensor chip 22, that is, along the direction away from the upper surface of the circuit board 3, the image sensor chip 22, the filter 24, and the imaging lens 23 are arranged in sequence.

[0106] like Figure 2 As shown, in a possible embodiment, the camera module includes a ceramic substrate 4, the light source 11 is mounted on the upper surface of the circuit board 3 through the ceramic substrate 4, and the projection area of ​​the ceramic substrate 4 on the upper surface of the circuit board 3 is smaller than the area of ​​the upper surface.

[0107] The light source 11 generates a large amount of heat during operation, and VCSEL is usually a porous structure, which is prone to deformation and fracture. Ceramic materials have the advantages of high heat dissipation efficiency and good thermal stability, which can improve the heat dissipation efficiency, thereby reducing the occurrence of heat deformation of the VCSEL chip, improving the working stability of the camera module, and more in line with actual use requirements. Appropriately reducing the area of ​​the ceramic substrate 4 can save the overall cost of the camera module.

[0108] like Figure 4 As shown, in a possible implementation manner, the first lens barrel 13 is mounted on the circuit board 3 through the ceramic substrate 4 .

[0109] By connecting the first lens barrel 13 to the ceramic substrate 4, the first lens barrel 13 can be easily positioned during installation, and the space occupied by the first lens barrel 13 on the circuit board 3 can be saved, so that the structure of the camera module can be more compact, which is conducive to the miniaturization design of the camera module.

[0110] like Figure 5 As shown, in a possible implementation, the camera module further includes a driving component 5 installed on the circuit board 3 for driving the light source 11 to emit light.

[0111] like Figure 5 As shown, in a possible implementation manner, the driver 5 is mounted on the circuit board through the ceramic substrate 4 , and the driver 5 and the light source 11 are located on the same side of the ceramic substrate 4 .

[0112] Through such a design, the ceramic substrate 4 can be used to dissipate heat for the driver 5, which is beneficial to improving the working stability of the driver 5. At the same time, arranging the driver 5 and the light source 11 on the same side of the ceramic substrate 4 can integrate the driver 5 into the first lens barrel 13, and can also reduce the space occupied by the driver 5 on the circuit board 3, which is beneficial to reducing the size of the circuit board 3 and reducing costs.

[0113] In a possible implementation manner, the circuit board 3 has a lower surface opposite to the upper surface, and the driving member 5 can be installed on the lower surface of the circuit board 3 .

[0114] By installing the driving member 5 on the side of the circuit board where the transmitting module 1 and the receiving module 2 are arranged, the utilization rate of the circuit board 3 can be improved, which is conducive to reducing the volume of the circuit board 3, thereby saving costs.

[0115] like Figure 6 As shown, in a possible implementation, a recessed portion 31 is provided on the lower surface of the circuit board 3, and the recessed portion 31 may be a groove or a through hole, etc. The recessed portion 31 is recessed toward the direction close to the upper surface of the circuit board 3, and at least a part of the driving member 5 is located in the recessed portion 31.

[0116] By arranging the driving member 5 on the side of the circuit board 3 away from the transmitting module 1 and the receiving module 2, the utilization rate of the circuit board 3 can be improved, the area of ​​the circuit board 3 can be reduced, and the size of the circuit board 3 can be reduced. The recessed portion 31 can facilitate the positioning of the driving member 5, and is also conducive to reducing the size of the camera module in the thickness direction of the circuit board 3.

[0117] like Figure 6 As shown, in a possible implementation manner, a reinforcing plate 6 may be provided on the lower surface of the circuit board 3 .

[0118] In a possible implementation, the circuit board 3 may be a flexible circuit board 3 or a rigid-flexible board or a printed circuit board 3 .

[0119] The reinforcing plate 6 can be but is not limited to a steel sheet reinforcement. When the circuit board 3 is a hard-soft board, it can also include a reinforcing plate to improve the flatness of the camera module. The reinforcing plate 6 can be provided with an avoidance structure at a position corresponding to the recessed portion 31 .

[0120] Since the camera module provided in the embodiment of the present application can omit components such as DOE, protection circuit, photodiode (PD), etc., the steps can be simplified during assembly, thereby improving assembly efficiency and reducing costs.

[0121] Based on the TOF camera module involved in the above embodiments, the embodiment of the present application further provides an electronic device, the electronic device includes a camera module and a control unit, the camera module is used to measure the depth information of the target object, and the control unit is used to operate and control at least one function of the electronic device according to the depth information. The camera module can be the TOF camera module involved in any of the above embodiments. Since the camera module has the above technical effects, the electronic device including the camera module also has the corresponding technical effects, which will not be repeated here.

[0122] The embodiment of the present application provides a time-of-flight TOF camera module and an electronic device. The camera module includes a circuit board 3 and a transmitting module 1 and a receiving module 2 arranged on the upper surface of the circuit board 3. The transmitting module 1 includes a light source 11 for transmitting N beams of point light and a projection lens 12 for collimating and projecting the N beams of point light. The receiving module 2 is used to receive N returned depth light signals and convert them into electrical signals. Among them, the field of view FOV of the projection lens 12 satisfies 65°<FOV<80°, the F number of the projection lens 12 is less than 1.9, and the focal length is 1.2<f<1.4. Through the design of the projection lens 12, the N beams of point light emitted by the light source 11 are directly projected onto the target object with a predetermined field of view and intensity after passing through the projection lens 12, without the need to copy the light signal, and without the need to set up a light signal copying element, which saves costs, reduces the thickness of the entire camera module, and reduces the difficulty of assembling the camera module. Furthermore, since the N beams of point light directly reach the target object after passing through the projection lens, the loss of light is reduced, and the utilization rate of the light source is greatly improved.

[0123] The above description is only the preferred embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A time-of-flight (TOF) camera module, which is used to project a speckle light array consisting of N speckles to a target object at a target field of view, characterized in that: The camera module includes: A circuit board, the upper surface of which at least includes a non-overlapping first area and a second area; A transmitting module, which is arranged in the first area of the circuit board. The transmitting module includes a light source and a projection lens. The light source is used to emit N beams of point light. The field of view FOV of the projection lens satisfies: 65° < FOV < 80°. The F-number of the projection lens is less than 1.9, and the focal length 1.2mm < f < 1.4mm. The projection lens is used to collimate the N beams of point light and project the N beams of point light onto the target object to generate a speckle light array composed of the N speckles on the target object; and A receiving module, which is arranged in the second area of the circuit board. The receiving module is used to receive the depth light signal returned after the N speckle arrays irradiate the target object and is used to convert the depth light signal into an electrical signal; A diaphragm and a lens group are sequentially arranged on the projection lens along the imaging side to the light source side. The lens group includes at least two lenses; The lens group includes a first lens, a second lens, and a third lens sequentially arranged along the imaging side to the light source side; The first lens is a lens with positive optical power. The first lens is concave on the near-axis imaging side and convex on the near-axis light source side. At least one of the two surfaces of the first lens is an aspherical surface; The second lens is a lens with negative optical power. The second lens is concave on the near-axis imaging side and convex on the near-axis light source side, and at least one of the two surfaces of the second lens is an aspherical surface; The third lens is a lens with positive optical power. The third lens is convex on the near-axis imaging side, and at least one of the two surfaces of the third lens is an aspherical surface; The near-axis curvature radius of the imaging side surface of the first lens is R1, and the near-axis curvature radius of the light source side surface is R2. The first lens satisfies 2 < R1 / R2 < 4.5; The near-axis curvature radius of the imaging side surface of the second lens is R3, and the near-axis curvature radius of the light source side surface is R4. The second lens satisfies 0.25 < R3 / R4 < 0.45; The near-axis curvature radius of the imaging side surface of the third lens is R5, and the near-axis curvature radius of the light source side surface is R6. The third lens satisfies -0.2 < R5 / R6 < 0.

1.

2. The TOF camera module according to claim 1, characterized in that: The projection lens satisfies: , where f is the focal length of the projection lens, Y is the maximum object height of the projection lens, and TTL is the distance between the aperture surface and the imaging surface of the projection lens.

3. The TOF camera module according to claim 1, characterized in that: The projection lens satisfies: 0.3 < f / TTL < 0.5, where f is the focal length of the projection lens and TTL is the distance between the diaphragm plane and the imaging plane of the projection lens.

4. The TOF camera module according to claim 1, characterized in that: The projection lens satisfies: 0.2 < Y / TTL < 0.4, where Y is the maximum object height of the projection lens and TTL is the distance between the diaphragm plane and the imaging plane of the projection lens.

5. The TOF camera module according to claim 1, characterized in that: The field of view FOV of the projection lens = 71.9°; 6. The TOF camera module according to claim 1, characterized in that: The F-number of the projection lens is equal to 1.76; 7. The TOF camera module according to claim 1, characterized in that: The camera module includes a first lens barrel and a second lens barrel. The receiving module includes an image sensor chip, an imaging lens, and a filter; The first lens barrel is installed in the first area of the circuit board. The projection lens is fixed to the first lens barrel and is arranged above the light source; The second lens barrel is installed in the second area of ​​the circuit board, the image sensor chip is accommodated in the second lens barrel, the imaging lens is fixed in the second lens barrel and arranged above the image sensor chip, and is used to image the depth light signal to the image sensor chip, and the filter is located between the imaging lens and the image sensor chip.

8. The TOF camera module according to claim 7, characterized in that: The camera module also includes a ceramic substrate, the light source is arranged on the prime circuit board through the ceramic substrate, and the projection area of ​​the ceramic substrate on the upper surface of the circuit board is smaller than the area of ​​the upper surface.

9. The TOF camera module according to claim 8, characterized in that: The first lens barrel is mounted on the circuit board through the ceramic substrate.

10. The TOF camera module according to claim 1, characterized in that: The camera module also includes a driving component, which is installed on the circuit board and is used to drive the light source to emit light.

11. The TOF camera module according to claim 10, characterized in that: The driving component is mounted on the circuit board through a ceramic substrate, and the driving component and the light source are located on the same side of the ceramic substrate.

12. The TOF camera module according to claim 10, characterized in that: The circuit board has a lower surface opposite to the upper surface, the lower surface is provided with a recessed portion recessed toward the upper surface, and at least a portion of the driving member is located in the recessed portion.

13. The TOF camera module according to claim 1, characterized in that: The circuit board is a flexible circuit board, a rigid-flexible circuit board, or a printed circuit board.

14. The TOF camera module according to claim 1, characterized in that: A reinforcing plate is arranged on the lower surface of the circuit board.

15. An electronic device, characterized in that: include: The time-of-flight TOF camera module according to any one of claims 1 to 14, wherein the time-of-flight TOF camera module is used to measure depth information of a target object; A control unit is used to perform operation control on at least one function of the electronic device according to the depth information.

Images