CN113834640B

CN113834640B - Method for determining optical center deviation of thermal imaging module, optical center alignment method and device

Info

Publication number: CN113834640B
Application number: CN202111165818.5A
Authority: CN
Inventors: 温俊阳
Original assignee: Hangzhou Micro Image Software Co ltd
Current assignee: Hangzhou Micro Image Software Co ltd
Priority date: 2021-09-30
Filing date: 2021-09-30
Publication date: 2024-03-01
Anticipated expiration: 2041-09-30
Also published as: CN113834640A

Abstract

The specification provides a method for determining optical center deviation of a thermal imaging module, an optical center alignment method and an optical center alignment device. The optical center alignment method comprises the following steps: determining the central position of an imaging target surface of a sensor chip of the thermal imaging module; acquiring a first image signal acquired by a sensor chip in a state that a lens assembly of a thermal imaging module is positioned right in front of the sensor chip; determining a position of an optical center of the lens assembly corresponding to an optical center of the imaging target surface by using the first image signal; determining deviation of the optical center of the lens assembly relative to the center of the sensor chip according to the optical center position and the center position of the imaging target surface; when the deviation does not meet the allowable deviation condition, the relative position between the lens assembly and the sensor chip is adjusted to reduce the deviation of the optical center of the lens assembly relative to the center of the sensor chip. The alignment scheme of the present disclosure can perform optical center alignment on the thermal imaging module.

Description

Method for determining optical center deviation of thermal imaging module, optical center alignment method and device

Technical Field

The present document relates to the field of thermal imaging technologies, and in particular, to a method for determining deviation of optical centers of thermal imaging modules, and a method and device for aligning optical centers.

Background

The thermal imaging module includes a flexible board (Flexible Printed Circuit, FPC), a sensor chip, and a lens assembly. When the lens is wide-angle, the thermal imaging module can cause that the optical center of the lens is not in the center of the photosensitive Die plane when the thermal imaging module images because of the relative offset error of the photosensitive Die part in the sensor chip in the package, the dimension processing error of the lens component and the error accumulation of the lens component placed on the plane of the flexible board (Flexible Printed Circuit, FPC), and finally, the whole machine images are eccentric (for example, the deviation is delta L), the image has the phenomenon of dark angle and the like, and even the shooting precision of the thermal imaging sighting device can be influenced when the deviation is larger.

Thus, there is a need for a more reliable thermal imaging module optical center alignment scheme to more precisely align the thermal imaging module optical center.

Disclosure of Invention

The embodiment of the specification provides a method for determining optical center deviation of a thermal imaging module, wherein the thermal imaging module comprises a sensor chip and a lens assembly, and the method comprises the following steps:

determining the central position of an imaging target surface of the sensor chip;

acquiring a first image signal acquired by a sensor chip in a state that a lens assembly is positioned right in front of the sensor chip;

Determining a position of an optical center of the lens assembly corresponding to an optical center of the imaging target surface by using the first image signal;

and determining the deviation of the optical center of the lens assembly relative to the center of the sensor chip according to the optical center position and the center position of the imaging target surface.

Optionally, determining the center position of the imaging target surface of the sensor chip includes:

acquiring a second image signal on the imaging target surface acquired by the sensor chip before the lens assembly is moved to the sensor chip after the thermal imaging module is electrified;

and determining the center of a second image area where the image formed by the second image signal on the imaging target surface is located as the center position of the imaging target surface.

Further, determining an image area formed by the second image signal on the imaging target surface comprises:

acquiring an image formed by the second image signal on the imaging target surface;

and carrying out non-uniformity correction on an image formed by the second image signal on the imaging target surface to obtain a corrected image so as to determine the center position of the imaging target surface according to the area of the corrected image.

Optionally, the image formed by the imaging target surface is a rectangular image, and the center of the rectangular image is the center position of the imaging target surface.

Optionally, determining, using the first image signal, a position of an optical center of the lens assembly corresponding to an optical center of the imaging target surface includes:

determining a first image area where an image formed on the imaging target surface by the first image signal is located, wherein the first image area is a circular area;

and determining the center of the circular area as the position of the optical center of the lens assembly corresponding to the optical center of the imaging target surface.

In a second aspect, embodiments of the present disclosure provide a method for aligning optical centers of a thermal imaging module, the thermal imaging module including a sensor chip and a lens assembly, the method comprising:

according to the method for determining the optical center offset of the thermal imaging module according to any one of the embodiments of the first aspect, the deviation of the optical center of the lens assembly relative to the center of the sensor chip is determined;

when the deviation does not meet the allowable deviation condition, the relative position between the lens assembly and the sensor chip is adjusted to reduce the deviation of the optical center of the lens assembly relative to the center of the sensor chip.

Optionally, when the deviation does not meet the allowable deviation condition, adjusting a relative position between the lens assembly and the sensor chip to reduce a deviation of an optical center of the lens assembly with respect to a center of the sensor chip, including:

And when the deviation does not meet the allowable deviation condition, controlling the lens assembly to move a preset step distance towards the center of the sensor chip along the radial direction during each adjustment.

Optionally, the deviation of the optical center of the lens assembly with respect to the center of the sensor chip includes:

before adjusting the relative position between the lens assembly and the sensor chip, the optical center of the lens assembly deviates from the center of the sensor chip; or alternatively

After adjusting the relative position between the lens assembly and the sensor chip, the optical center of the lens assembly is offset relative to the center of the sensor chip.

Optionally, the deviation of the optical center of the lens assembly relative to the center of the sensor chip is a distance deviation or an abscissa deviation.

Optionally, the allowable deviation condition includes: the distance deviation is smaller than a first preset deviation threshold; alternatively, the abscissa and ordinate deviations are both less than a second preset deviation threshold.

In a third aspect, embodiments of the present disclosure further provide a thermal imaging module optical center deviation determining device, including:

a first determining module for determining the center position of an imaging target surface of a sensor chip of the thermal imaging module;

The acquisition module acquires a first image signal acquired by the sensor chip in a state that a lens assembly of the thermal imaging module is positioned right in front of the sensor chip;

a second determining module for determining the optical center position of the lens assembly corresponding to the imaging target surface by using the first image signal;

and the third determining module is used for determining deviation of the optical center of the lens assembly relative to the center of the sensor chip according to the optical center position and the center position of the imaging target surface.

Optionally, the first determining module is specifically configured to: acquiring a second image signal on the imaging target surface acquired by the sensor chip before the lens assembly is moved to the sensor chip after the thermal imaging module is electrified; determining the center of a second image area where an image formed by the second image signal on the imaging target surface is located as the center position of the imaging target surface;

the third determining module is specifically configured to: determining a first image area where an image formed on the imaging target surface by the first image signal is located, wherein the first image area is a circular area; determining the center of the circular area as the position of the optical center of the lens assembly corresponding to the optical center of the imaging target surface;

The first determining module is specifically configured to, when acquiring the second image signal on the imaging target surface acquired by the sensor chip: acquiring a third image signal on the imaging target surface before the lens assembly is moved to the sensor chip after the thermal imaging module is powered on; and carrying out non-uniformity correction on the third image signal to obtain the second image signal.

In a fourth aspect, embodiments of the present disclosure further provide a thermal imaging module optical center alignment apparatus, including:

the third determining module is used for determining deviation of the optical center of the lens assembly relative to the center of the sensor chip according to the optical center position and the center position of the imaging target surface;

and the fine adjustment moving module is used for adjusting the relative position between the lens assembly and the sensor chip when the deviation does not meet the allowable deviation condition so as to reduce the deviation of the optical center of the lens assembly relative to the center of the sensor chip.

the fine adjustment mobile module is specifically used for: when the deviation does not meet the allowable deviation condition, controlling the lens assembly to move a preset step length distance to the center of the sensor chip along the radial direction during each adjustment;

the first determining module is specifically configured to, when acquiring the second image signal on the imaging target surface acquired by the sensor chip: acquiring a third image signal on the imaging target surface before the lens assembly is moved to the sensor chip after the thermal imaging module is powered on; performing non-uniformity correction on the third image signal to obtain the second image signal;

The deviation of the optical center of the lens assembly relative to the center of the sensor chip includes: before adjusting the relative position between the lens assembly and the sensor chip, the optical center of the lens assembly deviates from the center of the sensor chip; or, after adjusting the relative position between the lens assembly and the sensor chip, the optical center of the lens assembly deviates from the center of the sensor chip;

the deviation of the optical center of the lens assembly relative to the center of the sensor chip is a distance deviation or an abscissa-ordinate deviation, and the allowable deviation condition includes: the distance deviation is smaller than a first preset deviation threshold; alternatively, the abscissa and ordinate deviations are both less than a second preset deviation threshold.

In a fifth aspect, embodiments of the present disclosure further provide an optical center alignment system of a thermal imaging module, including:

thermal imaging module, control module and actuating mechanism, wherein:

the thermal imaging module comprises a sensor chip and a lens assembly;

the actuating mechanism is connected with the lens assembly and used for controlling the movement of the lens assembly;

the control module is connected with the execution mechanism and is used for determining deviation of the optical center of the lens assembly relative to the center of the sensor chip according to any one of the possible implementation methods of the first aspect, and when the deviation does not meet the allowable deviation condition, the execution mechanism is driven to control the lens assembly to move so as to adjust the relative position between the lens assembly and the sensor chip, so that the deviation of the optical center of the lens assembly relative to the center of the sensor chip is reduced.

Optionally, when the deviation does not meet the allowable deviation condition, the control module is used for driving the actuator to control the lens assembly to move a preset step distance towards the center of the sensor chip along the radial direction during each adjustment;

wherein, the deviation of the optical center of the lens assembly relative to the center of the sensor chip comprises: before adjusting the relative position between the lens assembly and the sensor chip, the optical center of the lens assembly deviates from the center of the sensor chip; or, after adjusting the relative position between the lens assembly and the sensor chip, the optical center of the lens assembly deviates from the center of the sensor chip;

Optionally, the thermal imaging module further comprises a flexible board, and the flexible board is used for connecting the sensor chip and the control module, and sending the image signals collected by the sensor chip to the control module.

Optionally, the system includes a thermostatic plate disposed at the light inlet of the lens assembly to form a thermostatic surface of the thermal imaging module.

Further, the temperature difference between the temperature of the thermostatic board and the ambient temperature is larger than a preset temperature difference threshold value.

Embodiments of the present specification also provide an electronic device comprising a processor and a memory electrically connected to the processor, the memory for storing a computer program, the processor for invoking the computer program to perform the method of the first or second aspect described above.

Embodiments of the present specification also provide a computer readable storage medium storing a computer program executable by a processor to implement the method of the first or second aspect described above.

On the one hand, in the embodiments of the present disclosure, the center position of the imaging target surface of the sensor chip and the center position of the imaging target surface corresponding to the optical center in the state of the lens assembly right in front of the sensor chip are determined, and the deviation of the optical center relative to the center of the sensor chip is determined according to the center position of the optical center and the center position of the imaging target surface, so that the optical center deviation of the thermal imaging module can be obtained more accurately, so that the optical center alignment can be performed based on the optical center deviation.

On the other hand, in the embodiment of the specification, the center position of the imaging target surface of the sensor chip and the center position of the imaging target surface corresponding to the optical center in the state of the right front of the sensor chip of the lens assembly are determined, the deviation of the optical center relative to the center of the sensor chip is determined according to the center positions of the optical center and the imaging target surface, and the relative position between the lens assembly and the sensor chip is adjusted based on the optical center deviation, so that the deviation of the optical center of the lens assembly relative to the center of the sensor chip is reduced, the optical center deviation of the thermal imaging module can be accurately obtained, and the optical center alignment is performed based on the optical center deviation.

Drawings

The accompanying drawings, which are included to provide a further understanding of the specification, illustrate and explain the exemplary embodiments of the present specification and their description, are not intended to limit the specification unduly. In the drawings:

FIG. 1 is a schematic diagram illustrating a method for determining a deviation of a photo center of a thermal imaging module according to an embodiment of the disclosure;

FIG. 2 is a schematic diagram of a thermal imaging module according to an embodiment of the disclosure;

FIG. 3 is a schematic diagram illustrating imaging using temperature differences of relative illumination of a lens according to an embodiment of the present disclosure;

FIG. 4 is a schematic diagram illustrating a method for aligning optical centers of a thermal imaging module according to an embodiment of the present disclosure;

FIG. 5 is a schematic diagram of a thermal imaging module optical center alignment system according to an embodiment of the present disclosure;

FIG. 6 is a schematic diagram illustrating a thermal imaging module optical center deviation determining device according to an embodiment of the present disclosure;

fig. 7 is a schematic structural diagram of an optical center alignment device of a thermal imaging module according to an embodiment of the disclosure;

fig. 8 is a schematic structural diagram of an electronic device according to an embodiment of the present disclosure.

Detailed Description

For the purposes of making the objects, technical solutions and advantages of the present specification more apparent, the technical solutions of the present specification will be clearly and completely described below with reference to specific embodiments of the present specification and corresponding drawings. It will be apparent that the described embodiments are only some, but not all, of the embodiments of the present specification. All other embodiments, which can be made by one of ordinary skill in the art without undue burden from the present disclosure, are intended to be within the scope of the present disclosure.

The following describes in detail the technical solutions provided by the embodiments of the present specification with reference to the accompanying drawings.

Fig. 1 is a schematic structural diagram of an optical center alignment system of a thermal imaging module according to an embodiment of the disclosure. It should be appreciated that in embodiments of the present description, the thermal imaging module includes a sensor chip and a lens assembly. The sensor chip is used for converting the incident light into an image signal and outputting the image signal to the imaging target surface; the lens assembly is movable, and when the lens assembly moves to the position right in front of the sensor chip, light rays are emitted onto the sensor chip through the lens assembly. Of course, it should be understood that the thermal imaging module may also include a flexible board connected to the sensor chip, which can convert signals of the sensor chip into image signals and output. In addition, the sensor chip may include a photosensitive chip Die, and the center of the sensor chip referred to in this specification, that is, the center of the photosensitive surface of the photosensitive chip of the sensor chip, will not be described in detail later. The specific structure and working principle of the thermal imaging module can refer to the related content of the prior art, and the embodiments of the present disclosure are not repeated here. Referring to fig. 1, the method may include:

s110, determining the center position of an imaging target surface of the sensor chip.

It should be appreciated that when the thermal imaging module is just powered up, and the lens assembly has not moved to the sensor chip, external light from the thermal imaging module is directly incident on the sensor chip and forms an image on the imaging target surface of the sensor chip. Of course, it should be understood that the area range of the image corresponding to the image signal of the imaging target surface at this time, that is, the area range of the imaging target surface, or the area range of the imaging target surface may be obtained by clipping according to a preset rule according to the area range of the image of the imaging target surface at this time. Thus, from the image on the imaging target surface at this time, the center position of the imaging target surface can be determined.

Alternatively, step S110 may be implemented as:

It should be appreciated that in this state after the thermal imaging module is powered up, where the lens assembly has not been moved in front of the sensor chip, light is directly incident on the photosensitive Die of the sensor chip and forms an image on the imaging target surface of the sensor chip. The imaging target surface range is consistent with the area range of the formed image at this time, or the imaging target surface range can be obtained by cutting according to the preset rule according to the area range imaged at this time. Therefore, according to the second image signal collected by the sensor chip and the related determination rule of the imaging target surface, the area of the imaging target surface can be determined, and then the central position of the imaging target surface can be determined, namely, the first central coordinate (X ', Y') of the center projection of the photosensitive surface (namely, the plane in which the photosensitive chip is located) of the sensor chip on the imaging target surface.

It should be appreciated that the particular rules and particular shapes of the imaging target surface may have different manners of determination from brand to brand. Alternatively, the image formed by the imaging target surface is a rectangular image, and the center of the rectangular image is the center position of the imaging target surface. It is assumed that the four vertex coordinates of the imaging target surface are (0, 0), (0, M), (N, 0), and (N, M), and the first center coordinate (X ', Y') is (N/2, M/2). Of course, it is not excluded that the imaging target surface takes other shapes, such as circular, regular hexagonal, etc.

Of course, it should be appreciated that to obtain more accurate coordinates of the center of the sensor chip, non-uniformity correction of the image formed by the imaging target surface at this time is required. Non-uniformity correction (Non-Uniformity Calibration, NUC) is where the thermal imaging module adjusts for small detector drift that occurs when the scene and environment changes. Typically, the thermal imaging module itself will interfere with its temperature readings, and to improve accuracy, the thermal imaging module will measure the infrared radiation of its optics and then adjust the image based on these readings. NUC adjusts the gain and offset for each pixel, resulting in a higher quality, more accurate image.

At this time, the acquiring of the second image signal on the imaging target surface acquired by the sensor chip may be specifically implemented as:

acquiring a third image signal on the imaging target surface before the lens assembly is moved to the sensor chip after the thermal imaging module is powered on;

and carrying out non-uniformity correction on the third image signal to obtain the second image signal.

It should be understood that the third image signal mentioned in the embodiment of the present disclosure may be an initial image signal on the imaging target surface acquired before the lens assembly is moved to the sensor chip after the thermal imaging module is powered up, or may be a corrected image signal on the imaging target surface acquired during the non-uniformity correction process.

In the present description embodiment, NUC correction may keep all pixels monotonically within a fixed environment. For example: by adjusting the internal parameters of the detector, all pixels of the detector are in monotonicity in the normal temperature environment. Meanwhile, part of pixels and other pixels have larger output difference (particularly bright or dark points, stripes or the like on an image), and are compensated by adopting a conventional filtering algorithm. The specific implementation manner of performing the non-uniformity correction on the image signal on the imaging target surface acquired by the sensor chip may refer to the prior art, and this embodiment of the present disclosure is not described herein again.

S120, acquiring a first image signal acquired by the sensor chip in a state that the lens assembly is positioned right in front of the sensor chip.

When the thermal imaging module is powered on, the lens assembly can be controlled to move to the right front of the sensor chip. The schematic positions of the lens assembly and other components in the thermal imaging module can be shown in fig. 2. Referring to fig. 2, the thermal imaging module is constructed as follows:

(1) representing an FPC flexible board;

(2) a photosensitive Die portion in the sensor chip;

(3) packaging of the sensor chip;

(4) lens assembly (including lens and lens mount).

It should be understood that a thermostatic plate may be provided at the light inlet of the lens assembly, the temperature of the thermostatic plate being constant and distributed uniformly. At this time, the plane of the thermostatic plate forms a thermostatic surface. Wherein, the sensor chip is close to the target surface side of the flexible board, and the lens component is close to the constant temperature surface side. Of course, it should be appreciated that to enable proper operation of the thermal imaging assembly, the temperature of the constant temperature surface may generally be set to a temperature difference from the ambient temperature greater than a preset temperature difference threshold, which may be empirically determined. Alternatively, the thermostatic plate may be a black body like element or device to provide a nominal temperature at a specified emissivity.

It should be appreciated that when the lens assembly is moved directly in front of the sensor chip, incident light of the thermal imaging module is incident from the lens assembly onto the sensor chip, and then an image signal is formed on the imaging target surface. At this time, the image signal on the imaging target surface acquired by the sensor chip is the first image signal in step S120.

S130, determining the optical center position of the lens assembly corresponding to the imaging target surface by using the first image signal.

Referring to fig. 3, when a constant temperature plane (e.g., black body) is provided in front of the thermal imaging module, because the center illuminance of the lens itself is different from the edge illuminance of the lens, the difference is imaged by the sensor into a regular pattern, typically a circle. Alternatively, step S130 may be implemented as:

An example is illustrated below in connection with fig. 3. For example: the center illuminance of the lens is 100%, the edge illuminance of the lens is 90%, and the temperature difference δt at a certain position between the center and the edge of the lens assembly is sensed by the thermal imaging sensor and a circular image is output. The circular center area (black area in fig. 3) is the center of the lens assembly. Since the coordinates of each pixel point on the circle are known, the center coordinate equation of the circle can be calculated by taking three points. At least three pixel points of the circular edge in the circular image are selected, and the center coordinates of the circular image are determined based on the pixel coordinates of the at least three pixel points. Of course, to avoid larger errors, it may be required that the pitch of the three selected pixels is larger than a predetermined threshold, such as a radius length of a circle, or a radius length of 1/2, etc. Taking three pixel coordinates as the following (X1, Y1), (X2, Y2), (X3, Y3) as an example, the specific calculation process of the center coordinates (X, Y) of the circular image is as follows:

X＝((x2^2-x1^2+y2^2-y1^2)*(2*(y3-y2))-(x3^2-x2^2+y3^2-y2^2)*(2*(y2-y1))/((2*(x2-x1))*(2*(y3-y2))-(2*(x3-x2))*(2*(y2-y1)))；

Y＝((2*(x3-x2))*(x2^2-x1^2+y2^2-y1^2)-(x3^2-x2^2+y3^2-y2^2)*(2*(x2-x1)))/((2*(x3-x2))*(2*(y2-y1))-(2*(y3-y2))*(2*(x2-x1)))。

Of course, it should be appreciated that after the coordinates (X, Y) are calculated, the X, Y coordinate values may be rounded off or the like according to the accuracy requirements.

And S140, determining deviation of the optical center of the lens assembly relative to the center of the sensor chip according to the optical center position and the center position of the imaging target surface.

It should be understood that, based on the coordinates of the optical center position and the coordinates of the center position of the imaging target surface, the deviation of the optical center of the lens assembly with respect to the center of the sensor chip, that is, the deviation between the center coordinates (X, Y) of the circular image and the center coordinates (X ', Y') of the imaging target surface mentioned in step S130 may be determined. It should be appreciated that the deviation between two coordinates may generally be represented by a distance deviation or an abscissa-ordinate deviation.

Specifically, when the deviation is a distance deviation, the distance deviation may be expressed as: (|X '-X|2+|Y' -Y|2)/(1/2).

Alternatively, when the deviation is an abscissa deviation, the abscissa deviation may be expressed as: x' -X; the ordinate deviation can be expressed as: y' -Y.

According to the embodiment of the specification, the center position of the imaging target surface of the sensor chip and the center position of the imaging target surface corresponding to the optical center of the lens assembly in the state of the front of the sensor chip are determined, and the deviation of the optical center relative to the center of the sensor chip is determined according to the center positions of the optical center and the imaging target surface, so that the optical center deviation of the thermal imaging module can be accurately obtained, and the optical center alignment can be performed based on the optical center deviation.

Fig. 4 is a schematic diagram of an optical center alignment method of a thermal imaging module according to an embodiment of the disclosure. As shown in FIG. 4, the method may include steps S110-S140 and step S210 as shown in FIG. 1. The specific implementation of steps S110 to S140 may refer to the embodiment shown in fig. 1, and will not be described again.

And S410, when the deviation does not meet the allowable deviation condition, adjusting the relative position between the lens assembly and the sensor chip so as to reduce the deviation of the optical center of the lens assembly relative to the center of the sensor chip.

It will be appreciated that, after the deviation of the two coordinates is obtained, it can be determined whether the deviation of the two coordinates satisfies the allowable deviation condition.

Alternatively, when the deviation of the optical center coordinates (X, Y) of the lens assembly with respect to the center coordinates (X ', Y') of the sensor chip is a distance deviation, the allowable deviation condition may be expressed by the following formula:

|X’-X|^2+|Y’-Y|^2<(δL)^2。

where δl represents the allowable distance deviation value.

Alternatively, when the deviation of the optical center coordinates (X, Y) of the lens assembly with respect to the center coordinates (X ', Y') of the sensor chip is an abscissa deviation, the allowable deviation condition may be expressed by the following formula:

|x '-x| < δl' and |y '-y| < δl'.

Where δl' represents the abscissa and ordinate deviations.

Preferably, the relationship between δl' and δl may be expressed by the following formula:

it will be appreciated, of course, that after the movement of the lens assembly is completed once, it is generally not possible to achieve a deviation within the allowable range, and therefore, it is generally necessary to cyclically adjust several times when controlling the lens assembly toward the center of the sensor chip. After each movement, the optical center coordinates of the lens assembly are required to be redetermined, and the deviation between the optical center coordinates and the center coordinates of the sensor chip is recalculated, and if the deviation does not meet the allowable deviation condition, the lens assembly is continuously controlled to move and the deviation is recalculated until the deviation meets the allowable deviation condition.

That is, in the embodiment of the present disclosure, the deviation of the optical center of the lens assembly with respect to the center of the sensor chip may include:

It should be appreciated that the optical center deviation adjustment may be performed according to a predetermined rule.

Alternatively, a preset step size may be set, each time the distance of the preset step size is moved. At this time, step S410 may specifically include:

It should be understood that reference herein to the radial direction is with respect to the axial direction of the lens assembly. The axial direction generally refers to the direction of the rotation center of the cylindrical object, that is, the direction common to the central axis, and the axis is the central axis. The axial direction of the embodiment of the present disclosure refers to the direction along the central axis of the lens assembly, and the radial direction refers to the direction perpendicular to the central axis of the lens assembly.

Of course, the distance of each movement may not be fixed. For example, when the deviation is greater than a certain preset threshold, the movement can be performed according to a first preset step length; and when the deviation is smaller than the preset threshold value, moving according to a second preset step length. Wherein the preset threshold is greater than the allowable deviation threshold, and the first preset step is greater than the second preset step. For example, the preset threshold is equal to 10 times the allowable deviation threshold, the first preset step size is equal to 5 times the second preset step size, and the second preset step size is equal to 0.5-1 times the allowable distance deviation threshold. It should be understood, of course, that the foregoing numbers are merely illustrative, and other numbers may be used in practice, and the embodiments of the present disclosure are not limited thereto.

Optionally, the deviation of the optical center of the lens assembly with respect to the center of the sensor chip is a distance deviation or an abscissa-ordinate deviation, and the allowable deviation condition includes: the distance deviation is smaller than a first preset deviation threshold; alternatively, the abscissa and ordinate deviations are both less than a second preset deviation threshold.

According to the embodiment of the specification, the center position of the imaging target surface of the sensor chip and the center position of the imaging target surface corresponding to the optical center in the state of the right front of the sensor chip of the lens assembly are determined, the deviation of the optical center relative to the center of the sensor chip is determined according to the center positions of the optical center and the imaging target surface, and the relative position between the lens assembly and the sensor chip is adjusted based on the optical center deviation, so that the deviation of the optical center of the lens assembly relative to the center of the sensor chip is reduced, the optical center deviation of the thermal imaging module can be accurately obtained, and the optical center alignment is performed based on the optical center deviation.

Based on this, this description embodiment can effectively improve thermal imaging sighting telescope product shooting precision on the one hand, reduces the user and calibrates the degree of difficulty for the product ease of use improves, and competitiveness improves. On the other hand, when the technology is used for manufacturing the thermal imaging module, bad phenomena such as dark corners are prevented from being generated, the production yield of the module can be greatly improved, the repair cost is reduced, and the market share is obviously improved.

Fig. 5 is a schematic structural diagram of a thermal imaging module optical center alignment system according to an embodiment of the present disclosure, referring to fig. 5, the thermal imaging module optical center alignment system may include:

a thermal imaging module 510, a control module 520, and an actuator 530, wherein:

the thermal imaging module includes a sensor chip 512 and a lens assembly 513;

the actuator 530 is connected to the lens assembly 513, and is configured to control movement of the lens assembly 513;

the control module 520 is connected to the actuator 530, and is configured to determine a deviation of the optical center of the lens assembly 513 with respect to the center of the sensor chip 512 according to the method of the embodiment shown in fig. 1, and when the deviation does not satisfy the allowable deviation condition, drive the actuator 530 to control the lens assembly 513 to move so as to adjust the relative position between the lens assembly 513 and the sensor chip 512, so as to reduce the deviation of the optical center of the lens assembly 513 with respect to the center of the sensor chip 512.

It should be understood that, the specific implementation of the control module 520 for determining the deviation of the optical center of the lens assembly 513 relative to the center of the sensor chip 512 may refer to the method of the embodiment shown in fig. 1, and this embodiment will not be described herein.

Optionally, when the control module 520 drives the actuator 530 to control the lens assembly 513 to move to adjust the relative position between the lens assembly 513 and the sensor chip 512, the method performed by the corresponding steps in the embodiment shown in fig. 4 may also be referred to, and the description of the embodiment is omitted herein.

Optionally, as shown in fig. 5, the thermal imaging module 510 further includes a flexible board 511. The positional relationship between the flexible board, the sensor chip 512 and the lens assembly 513 can be as shown in fig. 2. It should be appreciated that the flexible board 511 may be used to connect the sensor chip 512 with the control module and transmit the image signals collected by the sensor chip 512 to the control module 520.

Optionally, the optical center alignment system of the thermal imaging module may further include a thermostatic plate disposed at the light inlet of the lens assembly 513 to form a thermostatic surface of the thermal imaging module. Optionally, the temperature difference between the temperature of the thermostatic board and the ambient temperature is greater than a preset temperature difference threshold.

The control module 520 may also execute the method executed by the corresponding module in the embodiment shown in fig. 1 or fig. 4, and the specific implementation may refer to the embodiment shown in fig. 1, which is not described herein again.

Fig. 6 is a schematic structural diagram of a thermal imaging module optical center deviation determining device 600 according to an embodiment of the present disclosure, referring to fig. 6, the device includes:

A first determining module 610 for determining a center position of an imaging target surface of a sensor chip of the thermal imaging module;

an acquisition module 620, configured to acquire a first image signal acquired by the sensor chip in a state in which the lens assembly of the thermal imaging module is located right in front of the sensor chip;

a second determining module 630 for determining, using the first image signal, a position of an optical center of the lens assembly corresponding to an optical center of the imaging target surface;

and a third determining module 640 for determining deviation of the optical center of the lens assembly relative to the center of the sensor chip according to the optical center position and the center position of the imaging target surface.

The optical center alignment device of the thermal imaging module may also execute the method executed by the corresponding module in the embodiment shown in fig. 1, and the specific implementation may refer to the embodiment shown in fig. 1, and the description of this embodiment is not repeated here.

Fig. 7 is a schematic structural diagram of a thermal imaging module optical center alignment apparatus 700 according to an embodiment of the present disclosure, referring to fig. 7, the apparatus includes:

a first determining module 710 for determining a center position of an imaging target surface of a sensor chip of the thermal imaging module;

an acquisition module 720, configured to acquire a first image signal acquired by the sensor chip in a state in which the lens assembly of the thermal imaging module is located right in front of the sensor chip;

A second determining module 730 for determining, using the first image signal, a position of an optical center of the lens assembly corresponding to an optical center of the imaging target surface;

and a third determining module 740, configured to determine a deviation of the optical center of the lens assembly relative to the center of the sensor chip according to the optical center position and the center position of the imaging target surface.

The fine tuning movement module 750 adjusts the relative position between the lens assembly and the sensor chip to reduce the deviation of the optical center of the lens assembly with respect to the center of the sensor chip when the deviation does not satisfy the allowable deviation condition.

The optical center alignment device of the thermal imaging module may also execute the method executed by the corresponding module in the embodiment shown in fig. 1 and fig. 4, and the specific implementation may refer to the embodiment shown in fig. 1 and fig. 4, and the description of this embodiment is not repeated here.

For the above-described apparatus and system embodiments, the description is relatively simple, as it is substantially similar to the method embodiments, and reference will be made to the description of the method embodiments for relevant points. Further, it should be noted that, among the respective components of the apparatus of the present specification, the components thereof are logically divided according to functions to be realized, but the present specification is not limited thereto, and the respective components may be re-divided or combined as necessary.

Fig. 8 is a schematic structural diagram of an electronic device according to an embodiment of the present disclosure, and referring to fig. 8, the electronic device includes a processor, an internal bus, a network interface, a memory, and a nonvolatile memory, and may include hardware required by other services. The processor reads the corresponding computer program from the nonvolatile memory to the memory and then runs the computer program to form the optical center alignment device of the thermal imaging module on a logic level. Of course, other implementations, such as logic devices or combinations of hardware and software, are not excluded from the present description, that is, the execution subject of the following processing flows is not limited to each logic unit, but may be hardware or logic devices.

The network interface, processor and memory may be interconnected by a bus system. The bus may be an ISA (Industry Standard Architecture ) bus, a PCI (Peripheral Component Interconnect, peripheral component interconnect standard) bus, or EISA (Extended Industry Standard Architecture ) bus, among others. The buses may be classified as address buses, data buses, control buses, etc. For ease of illustration, only one bi-directional arrow is shown in FIG. 8, but not only one bus or type of bus.

The memory is used for storing programs. In particular, the program may include program code including computer-operating instructions. The memory may include read only memory and random access memory and provide instructions and data to the processor. The Memory may comprise a Random-Access Memory (RAM) or may further comprise a non-volatile Memory (non-volatile Memory), such as at least 1 disk Memory.

And the processor is used for executing the program stored in the memory and particularly executing the method of the embodiment shown in fig. 1 or fig. 4.

The method disclosed in the embodiments shown in fig. 1 and fig. 4 of the present specification may be applied to a processor or implemented by a processor. The processor may be an integrated circuit chip having signal processing capabilities. In implementation, the steps of the above method may be performed by integrated logic circuits of hardware in a processor or by instructions in the form of software. The processor may be a general-purpose processor, including a central processing unit (Central Processing Unit, CPU), a network processor (Network Processor, NP), etc.; but also digital signal processors (Digital Signal Processor, DSP), application specific integrated circuits (Application Specific Integrated Circuit, ASIC), field programmable gate arrays (Field-Programmable Gate Array, FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components. The various methods, steps and logic blocks disclosed in the embodiments of this specification may be implemented or performed. A general purpose processor may be a microprocessor or the processor may be any conventional processor or the like. The steps of a method disclosed in connection with the embodiments of the present specification may be embodied directly in hardware, in a decoded processor, or in a combination of hardware and software modules in a decoded processor. The software modules may be located in a random access memory, flash memory, read only memory, programmable read only memory, or electrically erasable programmable memory, registers, etc. as well known in the art. The storage medium is located in a memory, and the processor reads the information in the memory and, in combination with its hardware, performs the steps of the above method.

The electronic device may also execute the method of the embodiment shown in fig. 1 and fig. 4, and the specific implementation may refer to the embodiment shown in fig. 1 and fig. 4, which is not repeated herein.

Based on the same inventive concept, the present embodiments also provide a computer-readable storage medium storing one or more programs, which when executed by an electronic device comprising a plurality of application programs, cause the electronic device to perform the methods provided by the corresponding embodiments of fig. 1, 4.

Based on the same invention, the embodiment of the specification also provides a photo-center alignment system of the thermal imaging module, which comprises the photo-center alignment device of the thermal imaging module.

In this specification, each embodiment is described in a progressive manner, and identical and similar parts of each embodiment are all referred to each other, and each embodiment mainly describes differences from other embodiments. In particular, for system embodiments, since they are substantially similar to method embodiments, the description is relatively simple, as relevant to see a section of the description of method embodiments.

The foregoing describes specific embodiments of the present disclosure. Other embodiments are within the scope of the following claims. In some cases, the actions or steps recited in the claims can be performed in a different order than in the embodiments and still achieve desirable results. In addition, the processes depicted in the accompanying figures do not necessarily require the particular order shown, or sequential order, to achieve desirable results. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

It will be appreciated by those skilled in the art that embodiments of the present description may be provided as a method, system, or computer program product. Accordingly, the present specification may take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present description can take the form of a computer program product on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) having computer-usable program code embodied therein.

The present description is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems) and computer program products according to embodiments of the specification. It will be understood that each flow and/or block of the flowchart illustrations and/or block diagrams, and combinations of flows and/or blocks in the flowchart illustrations and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means which implement the function specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

In one typical configuration, a computing device includes one or more processors (CPUs), input/output interfaces, network interfaces, and memory.

The memory may include volatile memory in a computer-readable medium, random Access Memory (RAM) and/or nonvolatile memory, such as Read Only Memory (ROM) or flash memory (flash RAM). Memory is an example of computer-readable media.

Computer readable media, including both non-transitory and non-transitory, removable and non-removable media, may implement information storage by any method or technology. The information may be computer readable instructions, data structures, modules of a program, or other data. Examples of storage media for a computer include, but are not limited to, phase change memory (PRAM), static Random Access Memory (SRAM), dynamic Random Access Memory (DRAM), other types of Random Access Memory (RAM), read Only Memory (ROM), electrically Erasable Programmable Read Only Memory (EEPROM), flash memory or other memory technology, compact disc read only memory (CD-ROM), digital Versatile Discs (DVD) or other optical storage, magnetic cassettes, magnetic tape magnetic disk storage or other magnetic storage devices, or any other non-transmission medium, which can be used to store information that can be accessed by a computing device. Computer-readable media, as defined herein, does not include transitory computer-readable media (transmission media), such as modulated data signals and carrier waves.

It should also be noted that the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one … …" does not exclude the presence of other like elements in a process, method, article or apparatus that comprises the element.

It will be appreciated by those skilled in the art that embodiments of the present description may be provided as a method, system, or computer program product. Accordingly, the present specification may take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. Furthermore, the present description can take the form of a computer program product on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) having computer-usable program code embodied therein.

The foregoing is merely exemplary of the present disclosure and is not intended to limit the disclosure. Various modifications and alterations to this specification will become apparent to those skilled in the art. Any modifications, equivalent substitutions, improvements, or the like, which are within the spirit and principles of the present description, are intended to be included within the scope of the claims of the present description.

Claims

1. The method is characterized by being applied to an optical center alignment system of a thermal imaging module, wherein the optical center alignment system comprises a constant temperature plate and the thermal imaging module, the thermal imaging module comprises a sensor chip and a lens assembly, and the constant temperature plate is arranged at an optical inlet of the lens assembly to form a constant temperature surface of the thermal imaging module; the temperature difference between the temperature of the constant temperature plate and the ambient temperature is larger than a preset temperature difference threshold value; the central illuminance of the lens assembly is different from the edge illuminance of the lens assembly;

The method comprises the following steps:

acquiring a first image signal acquired by a sensor chip in a state that the constant temperature plate is arranged at an optical inlet of the lens assembly and the lens assembly is positioned right in front of the sensor chip;

determining deviation of the optical center of the lens assembly relative to the center of the sensor chip according to the optical center position and the center position of the imaging target surface;

determining, using the first image signal, a position of an optical center of the lens assembly corresponding to an optical center of the imaging target surface, comprising:

2. The method of claim 1, wherein,

determining a center position of an imaging target surface of the sensor chip includes:

3. The method of claim 2, wherein the second image area is a rectangular area.

4. A method as claimed in claim 2 or 3, wherein acquiring the second image signal on the imaging target surface acquired by the sensor chip before the lens assembly has been moved to the sensor chip after the thermal imaging module is powered up, comprises:

5. A method for aligning optical centers of a thermal imaging module, the method comprising:

determining deviation of the optical center of the lens assembly relative to the center of the sensor chip according to the thermal imaging module optical center deviation determining method of any one of claims 1 to 4;

6. The method of claim 5, wherein,

when the deviation does not satisfy the allowable deviation condition, adjusting the relative position between the lens assembly and the sensor chip to reduce the deviation of the optical center of the lens assembly relative to the center of the sensor chip, comprising:

7. The method of claim 5, wherein the misalignment of the optical center of the lens assembly relative to the center of the sensor chip comprises:

8. The method of claim 5, wherein the deviation of the optical center of the lens assembly from the center of the sensor chip is a distance deviation or an abscissa-ordinate deviation.

9. The method of claim 8, wherein,

The allowable deviation condition includes: the distance deviation is smaller than a first preset deviation threshold; alternatively, the abscissa and ordinate deviations are both less than a second preset deviation threshold.

10. A thermal imaging module optical center deviation determination apparatus, comprising:

the acquisition module is used for acquiring a first image signal acquired by the sensor chip in a state that the constant temperature plate is arranged at the light inlet of the lens assembly of the thermal imaging module and the lens assembly of the thermal imaging module is positioned right in front of the sensor chip; the temperature difference between the temperature of the constant temperature plate and the ambient temperature is larger than a preset temperature difference threshold value; the central illuminance of the lens assembly is different from the edge illuminance of the lens assembly;

11. The apparatus of claim 10, wherein the device comprises a plurality of sensors,

The first determining module is specifically configured to: acquiring a second image signal on the imaging target surface acquired by the sensor chip before the lens assembly is moved to the sensor chip after the thermal imaging module is electrified; determining the center of a second image area where an image formed by the second image signal on the imaging target surface is located as the center position of the imaging target surface; wherein the second image area is a rectangular area;

the first determining module is specifically configured to, when the second image signal on the imaging target surface acquired by the sensor chip is acquired before the lens assembly is moved to the sensor chip after the thermal imaging module is powered on: acquiring a third image signal on the imaging target surface before the lens assembly is moved to the sensor chip after the thermal imaging module is powered on; and carrying out non-uniformity correction on the third image signal to obtain the second image signal.

12. A thermal imaging module optical center alignment apparatus, comprising:

13. The apparatus of claim 12, wherein the device comprises a plurality of sensors,

the first determining module is specifically configured to: acquiring a second image signal on the imaging target surface acquired by the sensor chip before the lens assembly is moved to the sensor chip after the thermal imaging module is electrified; determining an image area formed by the second image signal on an imaging target surface; determining the center of a second image area where an image formed by the second image signal on the imaging target surface is located as the center position of the imaging target surface; wherein the second image area is a rectangular area;

The first determining module is specifically configured to, when the second image signal on the imaging target surface acquired by the sensor chip is acquired before the lens assembly is moved to the sensor chip after the thermal imaging module is powered on: acquiring a third image signal on the imaging target surface before the lens assembly is moved to the sensor chip after the thermal imaging module is powered on; performing non-uniformity correction on the third image signal to obtain the second image signal;

14. An optical center alignment system of a thermal imaging module, comprising:

thermal imaging module, control module and actuating mechanism, wherein:

the thermal imaging module comprises a sensor chip and a lens assembly;

the control module is connected with the execution mechanism and is used for determining deviation of the optical center of the lens assembly relative to the center of the sensor chip according to the method of any one of claims 1-5, and when the deviation does not meet the allowable deviation condition, the execution mechanism is driven to control the lens assembly to move so as to adjust the relative position between the lens assembly and the sensor chip, so that the deviation of the optical center of the lens assembly relative to the center of the sensor chip is reduced;

the system also comprises a constant temperature plate which is arranged at the light inlet of the lens assembly to form a constant temperature surface of the thermal imaging module; the temperature difference between the temperature of the constant temperature plate and the ambient temperature is larger than a preset temperature difference threshold value; the center illuminance of the lens assembly is different from the edge illuminance of the lens assembly.

15. The system of claim 14, wherein the system comprises a plurality of sensors,

When the deviation does not meet the allowable deviation condition, the control module is used for driving the actuating mechanism to control the lens assembly to move a preset step length distance towards the center of the sensor chip along the radial direction during each adjustment;

16. The system of claim 14, wherein the system comprises a plurality of sensors,

the thermal imaging module further comprises a flexible board, wherein the flexible board is used for connecting the sensor chip with the control module and sending image signals acquired by the sensor chip to the control module.

17. An electronic device, comprising:

a processor; and

a memory arranged to store computer executable instructions which, when executed, cause the processor to perform operations corresponding to the method of any of claims 1-8.