CN109819144B - TOF camera module and design method thereof - Google Patents
TOF camera module and design method thereof Download PDFInfo
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- CN109819144B CN109819144B CN201711170716.6A CN201711170716A CN109819144B CN 109819144 B CN109819144 B CN 109819144B CN 201711170716 A CN201711170716 A CN 201711170716A CN 109819144 B CN109819144 B CN 109819144B
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Abstract
The invention discloses a TOF camera module and a design method thereof, which are used for acquiring image information of a target object in at least one special scene, and are particularly sensitive to meridional direction light beams of reflected light beams of the target object. The special scene TOF camera module comprises a light source module and a photosensitive control module, wherein the photosensitive control module comprises at least one meridional lens and is sensitive to meridional light beams of reflected light beams of the target object, and the special scene TOF camera module is small in size, low in cost and good in application in a special scene.
Description
Technical Field
The invention relates to the field of camera shooting, in particular to a TOF camera shooting module and a design method thereof, wherein the TOF camera shooting module is suitable for some special scenes so as to better acquire image information of the special scenes.
Background
Time Of Flight (TOF) measures the three-dimensional structure or three-dimensional profile Of a target object (or a target object detection area) by using a Time interval t (often called pulse ranging) between transmission and reception Of a pulse signal from a measuring instrument or a phase difference ranging (phase difference ranging) generated when a laser beam travels back and forth to the target object once.
The TOF measuring instrument is a testing instrument prepared by using a flight time method, can simultaneously obtain a gray image and a distance image of a target object, and is widely applied to the fields of somatosensory control, behavior analysis, monitoring, automatic driving, artificial intelligence, machine vision, automatic 3D modeling and the like. TOF measuring instruments are of various types, taking a TOF camera as an example, whose measurement of the depth or three-dimensional structure of a target object is based mainly on the measurement of phase differences of pulsed signals or laser light. It typically includes a light source emitting module and a photosensitive receiving module, which cooperate with the photosensitive receiving module and generate depth information of the target object based on TOF depth measurements. More specifically, the light source emitting module emits a light wave of a specific wavelength band, the emitted light wave is reflected on the surface of the target object to be received by the photosensitive receiving module, and the photosensitive receiving module calculates the depth information of the target object according to the time difference or the phase difference between the emitted light wave and the received light wave. The TOF measuring instrument can acquire not only depth information of a target object, but also gray information and brightness information of the target object simultaneously, so that the TOF measuring instrument is applied to various fields.
In particular, the TOF measuring instrument may be applied to multiple fields to accurately acquire depth information of a target object instead of human eyes, such as the TOF measuring instrument may be applied to a home device to enable intelligent control of the home device by a user, to a robot device to enable a robot to have a three-dimensional vision function, to a mobile device to enable unmanned control of the mobile device, and so on. It is worth noting that TOF measuring instruments are applied to various electronic devices, and a big characteristic of the TOF measuring instruments applied to various fields is that: the TOF measuring instrument enables the set electronic equipment to have a three-dimensional visual function, vividly, the application of the TOF measuring instrument enables the electronic equipment to have a human eye function, and the human eye function of the electronic equipment is enabled to be more powerful than a normal human eye function. The three-dimensional visual function enables a plurality of electronic devices to have the obstacle avoidance function, and the intellectualization of the electronic devices is realized in the mode, however, the application of the conventional TOF camera module in some obstacle avoidance scenes or other special scenes is not considerable.
Specifically, in application scenarios such as robots and vehicle-mounted obstacle avoidance, or other special scenarios, the effective test range of the TOF measuring instrument is a bar-shaped area. In other words, in some special scenarios, such as an obstacle avoidance scenario, the test range of the TOF measuring instrument is a bar-shaped area. For example, when the TOF measuring instrument is applied to vehicle-mounted obstacle avoidance, the TOF measuring instrument only tests information conditions on the periphery of the vehicle and on the ground, and does not need to test conditions in the air. When applied to a scanning robot, the TOF measuring instrument also only needs to test the floor condition and not the ceiling condition. In this case, the test range of the TOF measuring instrument only requires the meridional direction of the TOF measuring instrument, but does not require the sagittal direction, so that in some special scenes, the test method of the TOF measuring instrument only requires the resolution in a certain direction of the TOF measuring instrument.
However, since the photosensitive element, the lens and the module of the existing general TOF measuring instrument are all set to be 4:3 or 16:9, when such TOF measuring instruments are applied to a special scene (such as an obstacle avoidance scene), the working range of the TOF measuring instruments is far larger than the actual range required by the test, which results in that the TOF measuring instruments test a non-effective region while testing an effective region, thus not only reducing the test efficiency of the TOF measuring instruments, but also introducing unnecessary stray light and distance measurement errors for testing the effective region.
For such special scenes (such as obstacle avoidance scenes), the optimal proportion of the TOF measuring instrument is 4:1 or 10:1, while existing lenses generally have uniform resolution in both the meridional and sagittal directions, when such lenses are adapted to the best ratio of the photosensitive elements, it is necessary to provide multiple sets of lenses in the TOF measuring instrument to compensate each other for the particular application of the particular scene. This results in a significant increase in the size and cost of TOF measuring instruments, which must be large enough to be housed in the electronics, and which cannot be placed in small spaces to acquire images of particular scenes. In addition, the cost of the TOF measuring instrument also limits the application of the TOF measuring instrument to a great extent, the cost expenditure of the lens is increased due to the arrangement of a plurality of groups of lenses in the TOF measuring instrument, the assembly difficulty of the TOF measuring instrument is increased, and the testing precision of the TOF measuring instrument can be directly influenced by the position difference between the lenses.
In summary, the conventional general TOF measuring instrument is not suitable for testing some special scenes (such as obstacle avoidance scenes), and has the following problems: not only are TOF measuring instruments costly and large in size, but such costly TOF measuring instruments also fail to obtain an accurate test of the active area of a particular scene.
Disclosure of Invention
An object of the present invention is to provide a TOF camera module and a design method thereof, wherein the TOF camera module optimizes the resolution requirement in a single direction, and reduces the resolution requirement in another direction, so that the TOF camera module can be applied to a special scene.
An object of the present invention is to provide a TOF camera module and a design method thereof, wherein the resolution of the TOF camera module in the meridional direction is optimized, so that the TOF camera module has good optical performance in the meridional direction.
An object of the present invention is to provide a TOF camera module and a design method thereof, wherein the resolution force in the direction of the sagittal of the TOF camera module is weakened, or the resolution force in the direction of the sagittal of the TOF camera module is not too much required, so as to reduce the cost of the TOF camera module.
An object of the present invention is to provide a TOF camera module and a design method thereof, wherein a test range of the TOF camera module is implemented as a bar region, so that the TOF camera module can be applied to some special scenes, such as an obstacle avoidance scene, to improve test accuracy of the TOF camera module in a targeted manner.
An object of the present invention is to provide a TOF camera module and a design method thereof, wherein the TOF camera module tests a special scene in a targeted manner, in other words, a test range of the TOF camera module is adapted to an actual range of the special scene, so as to avoid an influence of stray light on a test of the special scene and avoid unnecessary distance test errors.
An object of the present invention is to provide a TOF camera module and a design method thereof, wherein only one lens can be disposed in the TOF camera module, and the number of conventional lenses is replaced by one lens, so that the number of lenses of the TOF camera module is greatly reduced, and in this way, the size and the manufacturing cost of the TOF camera module are reduced.
The invention aims to provide a TOF camera module and a design method thereof, wherein the TOF camera module is small in lens number, so that the assembly difficulty of the TOF camera module in a special scene is reduced, the assembly cost of the TOF camera module is reduced, and the manufacturing efficiency of the TOF camera module is improved.
One objective of the present invention is to provide a TOF camera module and a design method thereof, wherein the TOF camera module has a low requirement on a photosensitive element, in other words, the photosensitive element of the TOF camera module only needs to have a strong one-way resolving capability, thereby reducing the manufacturing cost of the TOF camera module.
The invention aims to provide a TOF camera module and a design method thereof, wherein the TOF camera module has high light energy utilization rate, namely the TOF camera module is low in cost and strong in light induction performance.
The invention aims to provide a TOF camera module and a design method thereof, wherein the TOF camera module has high test precision and can effectively and quickly capture an image of a target object in a special scene, so that the TOF camera module is well applied in the special scene.
An object of the present invention is to provide a TOF camera module and a design method thereof, wherein the TOF camera module has a small size and can be installed in various places or various types of electronic devices to expand the application range of the TOF camera module.
The invention aims to provide a TOF camera module and a design method thereof, wherein the TOF camera module is low in cost and has accurate test precision when being applied to a special scene. According to an aspect of the present invention, a TOF camera module is provided for acquiring image information of a target object of at least one special scene, wherein the TOF camera module is sensitive to meridional light beams of a reflected light beam from the target object, so that the TOF camera module is suitable for the special scene, and the TOF camera module comprises:
at least one light source module, wherein the light source module comprises at least one light emitter, wherein the light emitter emits the emission beam toward the target object, and the emission beam is reflected by the target object to form at least one reflection beam; and
at least one photoreception receiving module, wherein the photoreception receiving module comprises at least one lens and at least one TOF image sensor, wherein the lens is arranged in an optical path of the TOF image sensor, so that the reflected light beam is received and processed after reaching the TOF image sensor through the lens, and the lens is sensitive to the meridional light beam of the reflected light beam.
According to an embodiment of the invention, the lens comprises at least one meridional lens, wherein the meridional lens is sensitive to the meridional beams of the reflected beam.
According to one embodiment of the invention, the meridional lens is implemented as an aspherical lens and is sensitive to the meridional beam of the reflected beam.
According to one embodiment of the invention, the curvature of the aspheric lens is related to the meridional beam sensitivity of the meridional lens to the reflected beam.
According to one embodiment of the invention, the number of meridional lenses is one.
According to one embodiment of the invention, the meridional lens is implemented as a rectangular area, wherein the size area of the rectangular area is not less than 4: 1.
According to one embodiment of the invention, the meridional lenses are implemented with a scale size of 4:1 or 20: 1.
According to one embodiment of the invention, the image working area of the TOF image sensor is implemented as a rectangular area, wherein the size area of the rectangular area is not less than 4: 1.
According to one embodiment of the invention, the TOF image sensor is communicatively connected to at least one external end device, wherein the external end device determines the image working area on the TOF image sensor.
According to one embodiment of the invention, the rectangular area formed by the image working area of the TOF image sensor is implemented as a 4:1 or 20: scale size of 1.
According to an embodiment of the present invention, the TOF camera module further includes a circuit board, wherein the light source module and the light sensing receiving module are disposed at different positions of the circuit board.
According to an embodiment of the present invention, the photoreception receiving module further includes at least one support frame, wherein the support frame is disposed on the circuit board, and the TOF image sensor and the lens are supported by the support frame.
According to an embodiment of the present invention, the photoreception receiving module further includes at least one filter element, wherein the filter element is disposed between the lens and the TOF image sensor to filter stray light of the reflected light beam.
According to one embodiment of the present invention, the light source module comprises at least one metal protective cover, wherein the metal protective cover defines an isolation cavity, and the light emitter and the diffusion element are supported by the metal protective cover.
According to an embodiment of the invention, the special scene is implemented as an obstacle avoidance scene.
According to an embodiment of the invention, the special scene is implemented as an obstacle avoidance scene.
According to another aspect of the present invention, a design method of a TOF camera module is provided, configured to acquire image information of a target object of at least one special scene, where the TOF camera module is sensitive to meridional beams of reflected beams from the target object, so that the TOF camera module is suitable for the at least one special scene, where the design method includes the following steps:
s1: assembling at least one light source module and at least one photosensitive receiving module on at least one circuit board, wherein the photosensitive receiving module is sensitive to meridional light beams of the reflected light beams.
According to an embodiment of the present invention, the step S1 further includes the steps of:
s11: assembling at least one TOF image sensor on the circuit board; and
s12: and assembling at least one lens on the optical path of the TOF image sensor.
According to one embodiment of the invention, the lens is sensitive to meridional beams of the reflected beam.
According to one embodiment of the invention, the lens comprises at least one meridional lens, wherein the meridional lens is sensitive to meridional beams of the reflected beam.
According to an embodiment of the invention, the meridional lens is implemented as an aspheric lens, wherein the curvature of the aspheric lens is related to the meridional beam sensitivity of the meridional lens to the reflected beam.
According to one embodiment of the invention, the TOF image sensor is sensitive to the meridional light beams of the reflected light beams.
According to one embodiment of the invention, the TOF image sensor is provided with at least one image working area, wherein the image working area receives the meridional light beams of the reflected light beams.
According to one embodiment of the invention, the TOF image sensor is implemented as a rectangular area, wherein the size area of the rectangular area is not less than 4: 1.
According to one embodiment of the invention, the TOF image sensor is implemented as a 4:1 or 20: scale size of 1.
Drawings
Fig. 1 is a diagram of practical application of a TOF camera module according to the invention in a particular scene.
Fig. 2 is an overall schematic diagram of a TOF camera module according to an embodiment of the invention.
Fig. 3 is a schematic cross-sectional view of a TOF camera module according to the above-described embodiment of the invention.
Fig. 4 is an exploded schematic view of a TOF camera module according to the above embodiment of the invention.
Fig. 5 is a schematic cross-sectional view of a lens of a TOF camera module according to the above embodiment of the invention.
Fig. 6 is a schematic view of the principle of the lens of the TOF camera module according to the above embodiment of the invention.
Fig. 7 is a schematic diagram of the operation principle of the TOF camera module according to the above embodiment of the invention.
Fig. 8 is an MTF diagram of the TOF camera module according to the above embodiment of the invention.
Fig. 9 is a schematic flow chart of a design method of a TOF camera module according to the invention.
Detailed Description
The following description is presented to disclose the invention so as to enable any person skilled in the art to practice the invention. The preferred embodiments in the following description are given by way of example only, and other obvious variations will occur to those skilled in the art. The basic principles of the invention, as defined in the following description, may be applied to other embodiments, variations, modifications, equivalents, and other technical solutions without departing from the spirit and scope of the invention.
It will be understood by those skilled in the art that in the present disclosure, the terms "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," and the like are used in an orientation or positional relationship indicated in the drawings for ease of description and simplicity of description, and do not indicate or imply that the referenced devices or components must be constructed and operated in a particular orientation and thus are not to be considered limiting.
It is understood that the terms "a" and "an" should be interpreted as meaning that a number of one element or element is one in one embodiment, while a number of other elements is one in another embodiment, and the terms "a" and "an" should not be interpreted as limiting the number.
Fig. 1 is a diagram of a TOF camera module according to the present invention applied to a special scene, which is implemented as an automobile obstacle avoidance scene in the embodiment, and it should be understood by those skilled in the art that the special scene is not limited to the automobile obstacle avoidance scene, and the embodiment is only exemplified. When the special scene is suitable for the automobile obstacle avoidance scene, at least one TOF (time of flight) measuring instrument is arranged on an automobile.
In the embodiment of the invention, the TOF camera module is arranged on the automobile to detect the surrounding environment information of the automobile, and the TOF camera module enables the automobile to have a three-dimensional visual function. Specifically, the TOF camera module is arranged around the automobile, for example, the TOF camera module arranged on the front side of the automobile is adapted to detect whether an obstacle exists in front of the automobile, the TOF camera module arranged on the rear side of the automobile is adapted to detect whether a rear-end vehicle exists behind the automobile, and the TOF camera module arranged on the side of the automobile is adapted to detect whether a security threat exists around the automobile. In addition, the TOF camera module can also be applicable to the blind area that detects this car, thereby makes the car can realize safe driving even unmanned driving.
However, it should be noted that in the special scene application of the above embodiment, the detection ranges of the TOF camera module are all bar-shaped regions. Specifically, when the TOF camera module is applied to vehicle-mounted obstacle avoidance, the TOF camera module only tests information conditions of the periphery of the vehicle and the ground, and does not need to test conditions in the air. Namely, the test range of the TOF camera module is implemented as a special range requirement, and a special scene of the special range requirement requires that the TOF camera module has good resolution in the meridional direction without excessive requirements on the sagittal direction of the TOF camera module. Of course, there are some special scenes that require good resolution in the sagittal direction of the TOF camera module, and there is no excessive requirement in the meridional direction of the TOF camera module. In short, different application scenarios have different resolution requirements on the TOF camera module.
In an embodiment of the present invention, the special scene is implemented as a scene in which the meridional direction is large and the sagittal direction is small, and specifically, the special scene is implemented as a bar-shaped region. In other words, in the embodiment of the present invention, the special scene has a large requirement on the resolution force of the TOF camera module in the meridional direction, and has a small requirement on the sagittal direction. Therefore, the invention provides a TOF camera module, wherein the TOF camera module has high meridional resolution and low sagittal resolution, and the special scene can be implemented as an obstacle avoidance scene, a bar scan scene, and the like, which is not limited in this respect.
As shown in fig. 2 to 5, the TOF camera module according to the above preferred embodiment of the invention is shown, the TOF camera module includes at least one light source module 10 capable of emitting light beams outwards and at least one photosensitive receiving module 20, wherein the TOF camera module is adapted to obtain depth information of at least one target object. Specifically, the light source module 10 emits the emitted light beam outwards, the emitted light beam is reflected to form at least one reflected light beam after reaching the target object, and the reflected light beam is received by the photosensitive receiving module 20, so that the photosensitive receiving module 20 can calculate the depth information of the target object according to the time difference or the phase difference between the emitted light wave and the reflected light wave. In other words, the TOF camera module obtains the depth information of the target object according to the time-of-flight principle, and it should be noted that the photosensitive receiving module 20 of the TOF camera module according to the present invention is implemented as a photosensitive module with strong unidirectional resolution, so as to be suitable for a special scene application.
As shown in fig. 2, the TOF camera module further includes a circuit board 30, and the light source module 10 and the light receiving module 20 are disposed at different positions of the circuit board 30, so that the light source module 10 and the light receiving module 20 can be communicatively connected to jointly complete the imaging of the target object by the TOF camera module.
It should be noted that, when the light source module 10 and the light sensing receiving module 20 are disposed on the circuit board 30, the circuit board 30 may further communicate with other embedded end devices, so that the TOF camera module is applied to other electronic devices. For example, the embedded end device may include, but is not limited to, a smart phone, a tablet computer, a portable computer, or other portable electronic device, wherein the electronic device is communicably connected to the TOF camera module to receive and process the depth information of the target object acquired by the TOF camera module. And the electronic equipment directly displays the depth information image of the measured target on a display screen through a display module, such as the display screen, so as to realize the functions of 3D modeling, AR and the like.
The circuit board 30 includes, but is not limited to, a rigid circuit board, a flexible circuit board, a rigid-flex board, and a ceramic and aluminum substrate. In the preferred embodiment of the present invention, the circuit board 30 is a hard circuit board having a light source module assembling area 31 and a light receiving module assembling area 32.
As shown in fig. 3 and 4, the light source module 10 includes at least one power supply 11 and at least one light emitter 12 electrically connected to the power supply 11, wherein the power supply 11 provides energy support for the light emitter 12, so that the light emitter 12 can emit the emitted light beam toward the target object. The power supply 11 is provided to the circuit board 30, the light emitter 12 is also provided to the circuit board 30 or the light emitter 12 is provided to the power supply 11, so that the wiring board 30 can control the light emission of the light emitter 12 by controlling the power supply 11.
It is worth mentioning that in some embodiments, the power supply 11 may be further implemented as a light-emitting circuit control, so that the light-emitting device 12 can not only be powered by the power supply 11, but also the power supply 11 can change the circuit characteristics of the light-emitting device 12 to adjust the type and the light-emitting intensity of the light-emitting device 12.
In another embodiment, the power supply 11 is built in the light emitter 12, and the light emitter 12 is disposed on the circuit board 30, so as to reduce the size and volume of the light source module 10.
It is worth mentioning that in the embodiment of the present invention, the light source module 10 is implemented as a Vertical Cavity Surface Emitter (VCSEL) including the power supply 11 of a VCSEL and the light emitter 12. Those skilled in the art will appreciate that the Vertical Cavity Surface Emitter (VCSEL) needs to be maintained within a specific temperature range for proper operation, i.e., the TOF camera module needs to be considered for heat dissipation, so as to maintain stable operation performance of the VCSEL. Accordingly, in the preferred embodiment of the present invention, the power supply 11 and the light emitter 12 are disposed at intervals, in such a way that, on the one hand, the total heat dissipation area of the light source module 10 is increased, and on the other hand, the heat generated by the power supply 11 and the light emitter 12 is prevented from affecting each other, so as to facilitate the heat dissipation of the light source module 10.
The TOF camera module further provides a safety protection structure to protect eyes of people. More specifically, the light source module 10 further includes a metal protection cover 14, wherein the metal protection cover 14 is disposed outside the light emitter 12 and is used as a part of a conduction circuit.
In some embodiments, the light source module 10 further includes a diffractive optical element 15(DOE), wherein the diffractive optical element 15 is used to change the phase and the spatial intensity of the light wave generated by the light emitter 12 to obtain the desired optical energy density. Those skilled in the art should understand that the modulated emitted laser has a higher environmental interference resistance, which is beneficial to improving the measurement accuracy of the TOF camera module, and the modulated emitted light wave does not cause damage to human eyes.
In particular, in this preferred embodiment of the invention, the diffractive optical element 15 is arranged between the metallic protective cover 14 and the light emitter 12. Specifically, the metal protection cover 14 is mounted on the circuit board 30 to form an isolation cavity 141 between the circuit board 30 and the metal protection cover 14, wherein the light emitter 12 and the diffractive optical element 15 are accommodated in the isolation cavity 141, and the emitting direction of the laser light is controlled through an optical window 142 disposed at the top end of the metal protection cover 14. The isolation cavity 141 is coupled to the optical window 142, on one hand, isolates the light emitter 12 to prevent radiation contamination, and on the other hand, the laser generated by the light emitter 12 can only reach the outside through the optical window 142, so as to limit the emitting direction of the laser to a limited extent.
In this way, the light source module 10 can emit the emission light beam toward the target object, the emission light beam is reflected to form the reflection light beam after reaching the target object, and the emission light beam is received by the photoreception receiving module 20, and it is noted that the unidirectional resolution of the photoreception receiving module 20 is strong. Specifically, the light receiving module 20 has a strong meridional resolution and a low sagittal resolution.
As shown in fig. 3 to 4, the photoreception receiving module 20 includes at least one TOF image sensor 21 and at least one lens 23, wherein the TOF image sensor 21 is configured to receive and/or sense the target object or the reflected light beam reflected by the target object and generate depth information of the target object. Specifically, the TOF image sensor 21 converts the emission light beam into the depth information of the target object, thereby preliminarily completing imaging of the photoreception receiving module 20.
It should be noted that the lens 23 is disposed in the optical path of the TOF image sensor 21, so that the reflected light beam entering the photoreception receiving module 20 can be processed by the optical path of the lens 23 before being received by the TOF image sensor 21.
The photoreception receiving module 20 further includes a holder 24, wherein the holder 24 is configured to hold the lens 23 in place. Preferably, the lens 23 is disposed in a position fixing hole 240 formed in the holder 24 to secure the lens 23 at a predetermined position.
The light sensing receiving module 20 further includes a filter element 25, wherein the filter element 25 is disposed between the TOF image sensor 21 and the lens 23, so as to filter stray light through the filter element 25, thereby improving the measurement accuracy of the TOF camera module. Preferably, the filter element 25 is configured to allow only the laser generated by the emitter 12 to pass through and finally irradiate to the TOF image sensor 21 for performing a photoelectric reaction, so as to convert an optical signal with depth information of the measured object into an electrical signal. It is worth mentioning that, in an embodiment of the present invention, the filter element 25 is disposed on the holding frame 24 and between the lens 23 and the TOF image sensor 21.
It should be noted that, in the present invention, the TOF camera module has high meridional resolution and low sagittal resolution, which also means that the lens 23 has high meridional resolution and low sagittal resolution. In other words, the TOF camera module is applied to a special scene that requires a high resolution in the meridional direction of the lens 23 and a low resolution in the sagittal direction of the lens 23.
The lens 23 includes at least one lens 231, and the reflected light beam reaches the TOF image sensor 21 through the lens 231. It should be noted that, since the sagittal resolution requirement of the lens 23 is low, the lens 23 may include only one or two lenses 231, unlike the conventional TOF camera module.
Specifically, in order to satisfy the resolution requirement in both the meridional direction and the sagittal direction, the conventional TOF camera module generally includes at least 4-5 lenses. However, the TOF camera module may include only one lens 231, and the lens 231 is implemented as an optical element with high meridional resolution and low sagittal resolution.
It should be noted that, since the TOF camera module includes only one lens 231, and the lens 231 is implemented as the meridional lens 231, the overall height of the lens 23 is reduced. Compared with a traditional TOF camera module, one meridian lens 231 of the TOF camera module can achieve the effect of 4-5 lenses of the traditional TOF camera module, and the size and height of the lens 23 of the TOF camera module are lower, so that the photosensitive receiving module 20 and the light source module 10 are located on the same horizontal plane of the circuit board 30. In this way, the size and volume of the TOF camera module are greatly reduced, and the manufacturing cost of the TOF camera module is reduced. In addition, it should be understood by those skilled in the art that since the lens 23 may only provide one lens 231 or two lenses 231, the optical performance of the lens 23 can be better controlled, which is unexpected for the prior art TOF camera module, so as to facilitate the improvement of the imaging capability of the TOF camera module and to greatly improve the product yield of the TOF camera module.
As shown in fig. 6, when the photoreception receiving module 20 is adapted to receive the emission beam from or reflected by the target object, the target object is defined as an off-axis object point, and in the optical field, a plane defined by the off-axis object point and the optical axis of the photoreception receiving module 20 is a meridian plane, and a direction of the meridian plane is also determined as a meridian direction. Similarly, in the photoreception receiving module 20, a plane passing through a principal ray and perpendicular to the meridian plane is a sagittal plane, and a direction of the sagittal plane is defined as the sagittal direction. At this time, the principal ray refers to a ray that exits from the edge of the target object, passes through the center of the aperture stop, and reaches the edge of the image.
And because the special scene mainly refers to scenes similar to an obstacle avoidance scene, the special scene only puts forward a higher resolution requirement on the meridional direction of the target object, and does not have much requirement on the sagittal direction of the target object. As can be seen from fig. 6, the special scene requirement puts a high resolution requirement on the meridional direction of the lens 231, but does not put much resolution requirement on the sagittal direction of the lens 231.
It should be mentioned that, when the light entering the lens 23 passes through only the single lens 231, it is difficult to satisfy the effect of uniform optical paths in both the meridional direction and the sagittal direction, so that in order to satisfy the optical path requirements in both the meridional direction and the sagittal direction of the conventional TOF camera module, a plurality of groups of lenses need to be arranged in the lens, and the optical paths of the plurality of groups of lenses compensate each other, so that the light of the TOF camera module has good resolving power in both the meridional direction and the sagittal direction. However, the conventional TOF camera module with multiple groups of lenses poses great challenges to the processing and cost of the TOF camera module.
The TOF camera module provided by the invention only needs to meet the requirement of resolution in the meridional direction, so the lens 23 can only comprise one lens 231, and the lens 231 is implemented as an optical element with high resolution in the meridional direction. Specifically, in the embodiment of the present invention, the lens 231 is designed by controlling the surface shape of the aspherical mirror, and since the lens 231 is an optical element, the arc of the curved surface of the lens 231 significantly affects the optical path of the reflected light beam. In other words, in order to make the meridional resolution of the lens 231 high, it is possible to change by changing the aspherical surface type of the lens 231, and the meridional resolution of the lens 231 is possible to change by changing the aspherical surface type of the lens 231.
In other words, the lens 23 includes at least one meridional lens 231, and the meridional lens 231 has a special aspheric cambered surface design, wherein the aspheric cambered surface design enables the meridional lens 231 to have high resolving power in the meridional direction, or the aspheric cambered surface design enables the meridional lens 231 to have good optical processing on the meridional direction of the emitted light beam. In an embodiment of the present invention, the lens 23 may include only one meridional lens 231, which greatly saves the cost of the lens 23.
Specifically, since the lens 23 only requires the meridional direction of the reflected light beam, the lens 23 may only include one or two meridional lenses 231, so that the size and volume of the TOF camera module are greatly reduced compared with those of the conventional TOF camera module. The lens of the conventional TOF camera module comprises more than 4 lenses, the number of the lenses is accumulated to increase the size of the conventional TOF camera module, however, the lens 23 of the TOF camera module only comprises one to two meridional lenses 231, so that the volume of the lens 23 is greatly reduced, and the volume of the photoreception receiving module 20 is also reduced.
In addition, the arrangement of the meridional lens 231 of the TOF camera module also greatly reduces the production cost and the assembly cost of the TOF camera module, the assembly of the photoreception receiving module 20 does not need to be carried out, and the arrangement of the meridional lens 231 not only reduces the cost of the lens but also facilitates the processing and assembly of processing personnel. In addition, the TOF camera module can be manufactured with a significantly higher yield by providing the meridional lens 231.
In addition, it should be noted that when only one meridional lens 231 is disposed on the lens 23, the passing rate of the meridional lens 231 for the reflected light beam and the utilization rate of the light energy are greatly increased, so that the meridional lens 231 can satisfy the normal operation of the photoreception module 20 in terms of the utilization of the light energy. Of course, to be suitable for the needs of the special scenario, the meridional lens 231 is preferably implemented as a rectangular area, wherein the size area of the rectangular area is not less than 4: 1. Specifically, in the embodiment of the present invention, the meridional lens 231 is implemented as a 4:1 size ratio or 20:1 size ratio, so that the lens 23 can be implemented as 4: a 1 size ratio or a 20:1 size ratio.
As shown in fig. 7, to match the optical characteristics of the lens 23, in some embodiments, the TOF image sensor 21 is implemented as a high aspect ratio TOF image sensor 21. The TOF image sensor 21 of the conventional TOF camera module is implemented with a size ratio of 4:3 or 16:9, and in order to meet the photosensitive surface of the TOF image sensor, the lens needs to be provided with multiple groups of lenses. However, the TOF camera module only needs to satisfy the resolution requirement in the meridional direction, so the effective photosensitive area of the TOF image sensor 21 only needs to sense the optical path from the meridional direction, so the TOF image sensor 21 is implemented as a high aspect ratio TOF image sensor 21, and it is worth mentioning that the size volume of the TOF image sensor 21 is implemented as a rectangular area, wherein the size area of the rectangular area is not less than 4: 1.
Specifically, in the embodiment of the present invention, the TOF image sensor 21 is implemented as 4: a size of 1 or 20:1 to suit the application of a particular scenario.
In an embodiment of the present invention, the TOF image sensor 21 is designed to be 4:1 or 20:1, and is disposed on the circuit board 30 to receive the reflected light beam passing through the lens 23. In another embodiment of the present invention, the TOF image sensor 21 is implemented in a normal size, and at this time, an image working area 211 is set on the TOF image sensor 21, the image working area 211 being set to 4:1 or 10:1 to receive said emission light beam through said lens 23.
As shown in fig. 7, the target object or the reflected light beam reflected from the target object passes through the lens 23, wherein the lens 23 is provided with a meridional lens 231, and after the reflected light beam is processed by the meridional lens 231, the meridional direction of the reflected light beam is optimized so that the meridional direction of the reflected light beam has good resolution performance. At this time, the reflected light beam emitted from the lens 23 reaches the TOF image sensor 21, wherein the TOF image sensor 21 is set to 4: a size volume of 1 or 10:1, or a high aspect ratio of the image working area 211 is disposed on the TOF image sensor 21 to receive the reflected beam.
In this way, good resolution performance of the TOF camera module in the meridian direction is ensured, so that the TOF camera module is suitable for application in special scenes. In addition, as the direction of the sagittal of the TOF camera module does not have much requirements, the size and the volume of the TOF camera module are reduced, and the cost is low, so that the TOF camera module is better and more widely applicable to some special scenes.
As shown in fig. 8, fig. 8 is an MTF schematic diagram of the TOF camera module according to the above embodiment of the invention, where the MTF schematic diagram shows that the solution force in the meridional direction of the TOF camera module is high, and the solution force in the sagittal direction of the TOF camera module is low, so that the TOF camera module can be adapted to a special scene.
According to another aspect of the present invention, a method for designing a TOF camera module, where the TOF camera module has a high resolution in the meridional direction and a low resolution in the sagittal direction, includes the steps of: assembling a light source module 10 and a light sensing receiving module 20 on at least one circuit board 30, wherein the light source module 10 and the light sensing receiving module 20 are disposed at different positions of the circuit board 30, the light source module 10 emits the emission beam to at least one target object, the emission beam is reflected by the target object to form the reflection beam, and the reflection beam is received by the light sensing receiving module 20 to form the TOF camera module.
The image resolution in the meridional direction of the photosensitive receiving module 20 is high, and the image resolution in the sagittal direction is low. The step of assembling the photoreception receiving module 20 further includes: a TOF image sensor 21 is disposed on the circuit board 21, and a lens 23 is disposed on an optical path of the TOF image sensor 21, wherein the reflected light beam enters the lens 23 and reaches the TOF image sensor 21 for reception.
It should be noted that the lens 23 is provided with at least one meridional lens 231, wherein the meridional lens 231 has high meridional resolution and low sagittal resolution, it is noted that the aspheric cambered surface of the meridional lens 231 is designed to make the meridional lens 231 have high meridional resolution, and the lens 23 may be provided with only one meridional lens 231.
1. It is worth mentioning that, in an embodiment of the present invention, the TOF image sensor 21 is designed to be 4:1 or 10:1, and is disposed on the circuit board 30 to receive the reflected light beam passing through the lens 23. In another embodiment of the present invention, the TOF image sensor 21 is implemented in a normal size, and at this time, an image working area 211 is provided on the TOF image sensor 21, the image working area 211 being defined by a rectangular area, wherein the size area of the rectangular area is not less than 4: 1.
Specifically, in the embodiment of the present invention, the image work area 211 is implemented as 4:1 or 20:1 to receive the emitted light beam exiting outward from the lens 23.
In this way, the size and volume of the photoreception receiving module 20 are much smaller than the size and volume of the photoreception receiving module 20 of a conventional TOF module, and the fabrication and assembly costs of the photoreception receiving module 20 are also lower than that of the conventional TOF module.
The invention further provides a TOF camera module, wherein the lens 23 of the TOF camera module is not different from a conventional lens, and the only difference is that the TOF image sensor 21 of the TOF camera module is provided with the image working area 211, so that the production cost of the TOF camera module is reduced.
Specifically, according to another aspect of the present invention, the present invention provides a TOF camera module, wherein a meridional direction resolving power of the TOF camera module is determined by the TOF image sensor 21, and the TOF image sensor 21 is provided with the image working area 211, so that the TOF camera module is more sensitive to the meridional direction light of the target object, and further the TOF camera module is suitable for a series of special scenes, such as an obstacle avoidance scene.
Furthermore, those skilled in the art will appreciate that the embodiments of the present invention described above and illustrated in the accompanying drawings are by way of example only and are not limiting of the invention. The objects of the invention have been fully and effectively accomplished. The functional and structural principles of the present invention have been shown and described in the examples, and any variations or modifications of the embodiments of the present invention may be made without departing from the principles.
Claims (20)
1. A TOF module of making a video recording for obtain the image information of target object in the special scene, in this special scene, TOF module of making a video recording's effective detection scope is the bar region, its characterized in that includes:
at least one light source module, wherein the light source module comprises at least one light emitter, the light emitter emits an emission light beam to the target object, and the emission light beam is reflected by the target object to form at least one reflection light beam; and
at least one photosensitive receiving module, wherein the photosensitive receiving module comprises at least one lens and at least one TOF image sensor, the lens is arranged in an optical path of the TOF image sensor, so that the reflected light beam is received after reaching the TOF image sensor through the lens and is processed by the TOF image sensor, the lens is sensitive to a meridional light beam in the reflected light beam, so that the TOF camera module is sensitive to the meridional light beam in the reflected light beam from the target object, and the TOF camera module is suitable for the special scene;
the lens comprises at least one meridional lens, and the resolution of the meridional lens in the meridional direction is higher than that of the meridional lens in the sagittal direction, so that the meridional lens is sensitive to the meridional light beams in the reflected light beams.
2. The TOF camera module of claim 1 wherein the meridional lens is an aspheric lens.
3. The TOF camera module of claim 2, wherein the curvature of the aspheric lens is related to the meridional beam sensitivity of the meridional lens to the reflected beam.
4. The TOF camera module of claim 1 wherein the number of meridional lenses is one.
5. The TOF camera module of claim 1, wherein the active area of the meridional lens is a rectangular area, wherein the ratio of the length to the width of the rectangular area is not less than 4: 1.
6. The TOF camera module of claim 5, wherein the rectangular area is implemented with a length to width dimension ratio of 4:1 or 20: 1.
7. The TOF camera module of claim 5, wherein the image working area of the TOF image sensor is a rectangular area, wherein the ratio of the length to the width dimension of the rectangular area is not less than 4: 1.
8. The TOF camera module of claim 7, wherein the rectangular area formed by the image working area of the TOF image sensor is implemented as a 4:1 or 20:1 length to width dimension ratio.
9. The TOF camera module of claim 1, further comprising a circuit board, wherein the light source module and the photoreception receiving module are disposed at different locations on the circuit board.
10. The TOF camera module of claim 9, wherein the photoreception receiving module further comprises at least one support frame, wherein the support frame is disposed on the circuit board, and the TOF image sensor and the lens are supported by the support frame.
11. The TOF camera module of claim 10, wherein the photoreception receiving module further comprises at least one filter element, wherein the filter element is disposed between the lens and the TOF image sensor to filter stray light of the reflected beam.
12. The TOF camera module of claim 11, wherein the light source module comprises at least a metal shield and a diffractive optical element, wherein the metal shield defines an isolated cavity, and the light emitter and the diffractive optical element are housed within the isolated cavity.
13. The TOF camera module according to any of claims 1 to 12, wherein said special scene is implemented as an obstacle avoidance scene.
14. A design method of a TOF camera module, configured to obtain image information of a target object in at least one special scene, where the TOF camera module is sensitive to a meridional light beam in a reflected light beam from the target object, so that the TOF camera module is suitable for the special scene, where an effective detection range of the TOF camera module is a bar region in the special scene, and the method is characterized by comprising the following steps:
s1: assembling at least one light source module and at least one photosensitive receiving module on at least one circuit board, wherein the photosensitive receiving module is sensitive to meridional light beams of the reflected light beams, wherein the photosensitive receiving module comprises at least one lens and at least one TOF image sensor, wherein the lens is disposed in an optical path of the TOF image sensor, so that the reflected light beams are received and processed after passing through the lens and reaching the TOF image sensor, wherein the lens comprises at least one meridional lens, and a resolution of the meridional lens in the meridional direction is higher than a resolution of the meridional lens in the sagittal direction, so that the meridional lens is sensitive to the meridional light beams in the reflected light beams.
15. The design method of the TOF camera module according to claim 14, wherein said step S1 further comprises the steps of:
s11: assembling the TOF image sensor on the circuit board; and
s12: and assembling the lens on an optical path of the TOF image sensor.
16. The method of designing a TOF camera module of claim 15, wherein the meridional lens is implemented as an aspheric lens, wherein the curvature of the aspheric lens is related to the meridional beam sensitivity of the meridional lens to the reflected beam.
17. The design method of the TOF camera module of claim 15, wherein said TOF image sensor is sensitive to said meridional beams of said reflected beams.
18. The method of claim 17, wherein the TOF camera module is configured with at least one image field, and wherein the image field receives the meridional beam of the reflected beam.
19. The method of designing a TOF camera module according to claim 18 wherein the TOF image sensor is implemented as a rectangular area wherein the ratio of the length to the width of the rectangular area is not less than 4: 1.
20. The method of designing a TOF camera module according to claim 19, wherein the TOF image sensor is implemented as a 4:1 or 20:1 length to width dimension ratio.
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| CN110595735B (en) * | 2019-09-29 | 2022-05-20 | 歌尔光学科技有限公司 | TOF module testing device, testing system and testing method |
| CN113472995B (en) * | 2020-03-31 | 2022-12-06 | 深圳市安思疆科技有限公司 | Dynamic automatic focusing system and method based on SPAD sensor receiving module |
| CN111596507B (en) * | 2020-05-11 | 2022-04-22 | 常州纵慧芯光半导体科技有限公司 | Camera module and manufacturing method thereof |
| CN114518642B (en) * | 2020-11-20 | 2024-03-22 | 余姚舜宇智能光学技术有限公司 | Linear TOF camera module, manufacturing method thereof and electronic equipment |
| CN214259197U (en) * | 2020-11-25 | 2021-09-24 | 深圳市杉川机器人有限公司 | TOF module, camera subassembly and robot of sweeping floor |
| CN114390759A (en) * | 2022-01-13 | 2022-04-22 | 北京瞰瞰智能科技有限公司 | Intelligent illumination system control method and device based on TOF camera and medium |
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