CN100342543C - Packaging equipment and method capable of selecting optimal distance to package optical sensing module - Google Patents

Abstract

A packaging device and method for selecting the best distance to package optical sensing module is composed of a base, an image analysis module, a distance regulation module and a stain detection module. The packaging equipment can package a lens and an optical sensor into an optical sensing module at an optimal packaging distance, has the function of detecting whether the lens or the optical sensor is stained or not, and can effectively, quickly and accurately complete the packaging and detection of the optical sensing module.

Description

Packaging equipment and method capable of selecting optimal distance to package optical sensing module

technical field

The invention provides a packaging device, especially a packaging device capable of selecting an optimal distance to package an optical sensing module.

Background technique

Light energy has been a very important source of energy in human life from ancient times to the present. Early humans used light energy for heating, fire or lighting. In modern times, they have a deeper understanding of the characteristics of light, and have derived more Applications, no matter in communication (optical fiber communication), image processing (digital camera), display equipment (liquid crystal screen) or other application fields, you can see technology products using optics. Components, such as optical sensors that detect the amount of light, have become one of the staple products produced by many electronics manufacturing companies today.

There are two types of optical sensors that are more common. One is the optical sensor used in digital cameras, called a charge-coupled device (CCD), which is a semiconductor that can record optical changes. The surface of the charge-coupled device has the ability to store charges and is arranged in a matrix. It can convert an image signal presented as an optical signal into an image signal stored in charge, and it can be judged according to the amount of charge stored in the charge-coupled device. The intensity of the image signal and restore to the original image. The other is an optical sensor made of the principle of a metal oxide semiconductor (CMOS), which is a semiconductor made of two elements, silicon and germanium, so that a semiconductor with N and P poles coexists on the CMOS. , the current generated by these two complementary effects can be recorded and interpreted as an image by the processing chip.

However, when a factory manufactures components for detecting the amount of light, it produces an optical sensing module including an optical sensor and a lens. Please refer to Figure 1. FIG. 1 is a schematic diagram of an optical sensing module 10 . The optical sensing module 10 includes a lens 14 , an optical sensor 16 and an interface circuit 18 . Generally speaking, the image range to be detected is much larger than the area of the optical sensor, so a lens is needed to reduce the external image and image it on the optical sensor. As shown in Figure 1, the luminous object 12 is imaged on the optical sensor through the lens 14 16 on. After the optical sensor 16 detects the optical signal of the received image, the optical signal is stored in the interface circuit 18 in the form of an electrical signal, and the interface circuit 18 can transmit these electrical signals with image information to other devices for image processing.

In the prior art, if the lens 14 is to be imaged on the optical sensor 16, an optimal distance must be adjusted between the lens 14 and the optical sensor 16 (D in the figure), so that the image formed on the optical sensor 16 is clearest . The factory must find this optimal distance when these optical sensing modules 10 are released, and at the same time fix the lens 14 and the optical sensor 16 on this optimal distance and package them up. After that, when users use the optical sensing module 10, they will Get the clearest image without worrying about focusing.

The current method for adjusting the optimal distance between the lens 14 and the optical sensor 16 is as follows. First, a luminous object 12 is placed outside the optical sensing module 10. The luminous object 12 will be imaged on the optical sensor 16 through the lens 14. At this time, the lens 14 and There is a distance between the optical sensors 16 (usually not the optimal distance), after which the optical sensors 16 will transmit the image signal to the interface circuit 18, and output the image signal to a computer through the interface circuit 18, and finally display the image signal on the computer screen. The image projected on the optical sensor 16 is displayed on the top. The tester judges whether the current imaging is clear from the image on the computer screen. If it is not clear, it means that the distance between the lens 14 and the optical sensor 16 is not the focal length of the lens. Therefore, manually adjust the distance between the lens 14 and the optical sensor 16, and at the same time While paying attention to the image on the computer screen. When the tester thinks that the image on the computer screen has been the clearest situation, then it is determined that the distance between the lens 14 and the optical sensor 16 has been the optimal distance, so the fixed packaging of the lens 14 and the optical sensor 16 becomes a possible The optical sensing module 10 shipped from the factory.

Although the previous method of packaging the optical sensing module can fix the optimal distance between the lens and the optical sensor during the packaging process, it has the following disadvantages: 1. Since the clarity and blur of the image are judged manually, it is often difficult for the tester Different focal lengths are defined differently, and the results of focusing are not clear and uniform. 2. People are not machines and are prone to fatigue, so manual focusing is less reliable. 3. The price of human resources is high and the speed is slow, which is not in line with the economic benefits of production. 4. If the lens of the optical sensing module itself is stained or there are small dead spots on the optical sensor, it cannot be detected quickly and effectively. Therefore, the present invention provides a packaging device capable of selecting an optimal distance to package the optical sensing module, which improves the shortcomings of the prior art and improves the accuracy and speed of packaging the optical sensing module.

Contents of the invention

The invention discloses a packaging device capable of selecting an optimal distance to package an optical sensing module, which includes a base for placing a lens and an optical sensor, the distance between the lens and the optical sensor is adjustable; an image An analysis module is used to analyze the image signal received by the optical sensor and output an analysis result signal according to the analysis result; a distance adjustment module is connected to the base and the image analysis module to be used for analysis based on the output of the image analysis module result signal, adjust the distance between the lens of the base and the optical sensor; and a stain detection module, connected with the base, used to judge whether the lens or the optical sensor is based on the image signal received by the optical sensor and a standard image defaced.

The present invention provides a method for packaging the optical sensing module with the optimal packaging distance between a lens and an optical sensor in the optical sensing module, comprising the following steps:

(a) read the image signal received by the optical sensor;

(b) the image analysis module extracts a part of the image signal from the image signal received by the optical sensor;

(c) The image analysis module calculates the image difference coefficient according to the captured part of the image signal, and the calculation of the image difference coefficient performs the following steps:

(c1) in the partial image signal, calculate the square of the difference between each adjacent partial image signal on the horizontal axis;

(c2) of the partial image signal, calculate the square of the difference between adjacent partial image signals on the vertical axis; and

(c3) adding the square of each image signal difference on the horizontal axis to the square of each image signal difference on the vertical axis to obtain the image difference coefficient;

(d) The distance adjustment module controls the adjustment mechanism to adjust the distance between the lens and the optical sensor according to the image difference coefficient, and the step (d) adjusts the distance between the lens and the optical sensor so that the lens and the optical sensor are within At this distance, the image difference coefficient calculated from the captured part of the image signal is the largest;

(e) fixing the lens and the optical sensor by the packaging module and completing the packaging of the optical sensing module.

The present invention is remarkable with respect to the effect of existing structure:

In the packaging equipment of the present invention that can select the optimal distance to package the optical sensing module, the lens on the base and the optical sensor are automatically adjusted to the optimal distance of the packaging by using the cooperation of the image analysis module and the distance adjustment module, so that the optical sensor After the detection module is packaged, the detected image can be clearly imaged in the internal optical sensor. In addition, the packaging equipment of the present invention has a stain detection module, which can simultaneously detect whether the lens and the optical sensor in the optical sensing module are stained during the packaging process. With a defaced position on the optical sensor. The present invention combines packaging and optical detection into the same process, and realizes the adjustment of packaging distance, packaging of optical sensing modules and detection optical modules in a fully automatic manner, which greatly shortens the time of previous packaging and testing, and reduces the cost of packaging and testing. It is beyond the reach of the prior art to reduce the required human resources, improve the factory efficiency of the optical sensing module, and improve the accuracy of packaging and inspection of the optical sensing module.

The existing method of packaging the optical sensing module uses testers to manually adjust the packaging distance between the lens and the optical sensor, often resulting in unclear focusing results due to different definitions of clear and blurred images. Furthermore, the human resources required by the previous method are expensive and the packaging speed is slow, which is not in line with the economic benefits of production. Moreover, it is impossible to quickly and effectively detect stains on the lens or dead pixels on the optical sensor during the packaging process. The present invention can select the optimal distance to package the packaging equipment of the optical sensing module, has an image analysis module, a distance adjustment module and a stain detection module, can automatically complete the packaging of the optical sensing module and the stain detection of the lens and the optical sensor, and has the advantages of high speed The advantages of fast, high efficiency, improved accuracy and low cost.

Description of drawings

FIG. 1 is a schematic diagram of a conventional optical sensing module.

FIG. 2 is a block diagram of a packaging device capable of selecting an optimal distance to package an optical sensing module according to a first embodiment of the present invention.

FIG. 3 is a schematic diagram of the change of the image difference coefficient FD when the distance between the lens and the optical sensor is different.

FIG. 4 is a block diagram of a packaging device capable of selecting an optimal distance to package an optical sensing module according to a second embodiment of the present invention.

Fig. 5 is a top view of the base structure in the packaging device of the present invention.

FIG. 6 is a flowchart of a method for detecting whether a lens or an optical sensor is defaced according to the present invention.

FIG. 7 is a flow chart of the method for determining the optimal packaging distance between a lens and an optical sensor in the optical sensing module of the present invention.

Description of figure number

10 Optical sensing module 14 Lens 16 Optical sensor

18 Interface circuit 30 Packaging equipment 32 Stain detection module

33 Memory 34 Distance Adjustment Module 36 Image Analysis Module

37 Logic device 31 Encapsulation module 35 Adjusting mechanism

38 Base 40 Packaging Equipment 44 Motor

46 Signal conversion interface 48 Processor 39 Lift cover

Detailed ways

Please refer to FIG. 2 , which is a block diagram of a packaging device 30 capable of selecting an optimal distance to package an optical sensing module according to a first embodiment of the present invention. The packaging device 30 includes a stain detection module 32 , a distance adjustment module 34 , an image analysis module 36 , a packaging module 31 and a base 38 . The base 38 is used to place a lens and an optical sensor, and there is a distance between the lens and the optical sensor. The base 38 also includes an adjustment mechanism 35 for adjusting the distance between the lens and the optical sensor. The image analysis module 36 is connected to the base 38 for analyzing the image signal received by the optical sensor on the base 38 . The distance adjustment module 34 is connected to the base 38 and the image analysis module 36. After the image analysis module 36 analyzes a group of image signals, the analysis result is transmitted to the distance adjustment module 34, and the distance adjustment module 34 decides whether to control the The adjustment mechanism 35 is used to adjust the distance between the lens and the optical sensor on the base 38. If the distance between the lens and the optical sensor must be changed, the distance adjustment module 34 controls the adjustment mechanism 35 in the base 38 to adjust the lens and the optical sensor. distance between sensors. The stain detection module 32 is connected to the base 38 and is used for judging whether the image signal received by the optical sensor is a perfect image signal without stain. The packaging module 31 is used to package the lens and the optical sensor to form the optical sensing module.

After receiving the image signal from the base 38 , the image analysis module 36 captures part of the image signal for analysis. The function of image analysis is accomplished by a logic device 37 inside the image analysis module 36 . The logic device 37 is able to judge the clarity of an image signal by evaluating a parameter called the image difference coefficient. If the image difference coefficient of an image is larger, it means that the image is clearer. Assuming that part of the captured image signal is composed of multiple pixel image signals, only the pixel at the position of Gb (or Gr) in the Color Filter is taken, and its image signal value is represented by g(x, y). Next, define a signal gradient Gx on the horizontal axis and a signal gradient Gy on the vertical axis, which are expressed in mathematical formulas as follows:

Gx=g(x,y)-g(x+1,y)

Gy=g(x,y)-g(x,y+1)

Therefore, the image difference coefficient FD can be expressed as follows:

$\mathrm{<span\; class="notranslate">\; FD</span>}<span\; class="notranslate">\; =</span>\underset{\mathrm{<span\; class="notranslate">\; x</span>}}{\mathrm{<span\; class="notranslate">\; \&Sigma;</span>}}\underset{\mathrm{<span\; class="notranslate">\; the\; y</span>}}{\mathrm{<span\; class="notranslate">\; \&Sigma;</span>}}<span\; class="notranslate">\; \{</span>{\mathrm{<span\; class="notranslate">\; G</span>}}_{\mathrm{<span\; class="notranslate">\; x</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; G</span>}}_{\mathrm{<span\; class="notranslate">\; the\; y</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; \}</span>$

When the lens in the base 38 and the optical sensor are separated by different distances, the image difference coefficient FD of the received image signal analyzed by the image analysis module 36 is also different. If the distance adjustment module 34 adjusts the distance between the lens on the base 38 and the optical sensor from near to far, different values of the image difference coefficient FD can be obtained.

Please refer to FIG. 3 . FIG. 3 is a schematic diagram of the change of the image difference coefficient FD when the distance between the lens and the optical sensor is different. The horizontal axis in the figure represents the distance between the lens and the optical sensor, and the vertical axis represents the image difference factor FD. As shown in FIG. 3 , when there is an optimal distance between the lens and the optical sensor, the image difference coefficient FD is the largest, and this distance is the distance at which the packaging device 30 packages and fixes the optical sensing module.

When selecting an optimal distance to package the optical sensing module, the operation of each module in the packaging equipment 30 is for example as follows: the distance adjustment module 34 first controls the base 38 to change the distance between the lens and the optical sensor, and during the distance change process The image analysis module 36 analyzes the image difference coefficient FD at each distance. If the image difference coefficient FD starts to decrease during the distance change process and is less than a degree, the distance adjustment module 34 controls the adjustment mechanism 35 in the base 38 to reversely adjust the distance between the lens and the optical sensor (that is, When the original distance is zoomed out, it will be zoomed in closer, and when the original distance is zoomed out, it will be zoomed out). On the contrary, if the image difference coefficient FD is getting larger and larger during the distance change process, continue to adjust the distance in the same direction, and keep on Until the image difference coefficient FD starts to decrease. It can be seen from FIG. 3 that the optimal distance occurs at the turning point of the curve, so the distance adjustment module 34 and the image analysis module 36 cooperate with each other to find the optimal distance. After that, the distance adjustment module 34 fixes the lens between the base and the optical sensor. The packaging of the optical sensing module is completed by the packaging module 31 at this optimal distance.

During the distance adjustment process, the distance adjustment module 34 changes the distance between the lens and the optical sensor with a different distance adjustment range. When searching for the first time, the distance adjustment module 34 is fixed to find the best focal length with a larger adjustment range. After the search exceeds the turning point of the curve, it will start a reverse search with a smaller adjustment range to find a more accurate focal length position. Repeat this until the search is completed with the smallest adjustment range. The purpose of doing this is to make the process of distance adjustment fast and accurate.

An important feature of the packaging device 30 of the present invention is that it has a stain detection module 32 that can detect stains on the lens or dead pixels of the optical sensor. The stain detection module 32 includes a memory 33 for storing a standard image. The standard image is a perfect reference image, which is stored in the memory 33 by receiving an image signal obtained by a set of perfect (no contamination) lenses and optical sensors from a sample light source. Assuming that the lens and the optical sensor to be packaged are of good quality and there is no problem, the image signal transmitted from the sample light source to the stain detection module 32 through the lens and the optical sensor should be exactly the same as the standard image stored in the memory 33 . On the contrary, if the image signal received by the stain detection module 32 is different from the standard image in the memory 33, it means that the lens or the optical sensor is stained.

The image signal received by the optical sensor transmitted from the base 38 to the stain detection module 32 is divided into a plurality of sub-image signals, each sub-image signal represents a pixel signal on the optical sensor, and each pixel signal corresponds to a position of the optical sensor. On the other hand, the standard image is also decomposed into a plurality of sub-standard images, and each sub-standard image also corresponds to a position of the optical sensor. One by one comparison of the standard images, if the comparison is found to be inconsistent, it can be known that the sub-image signals corresponding to those positions do not match, and thus the position of the stain on the optical sensor or lens can be deduced.

In addition, the stain detection of the present invention is not necessarily completed by an independent stain detection module, and the stain detection function can be completed by the circuit in the image analysis module. Therefore, the packaging device capable of selecting the optimal distance to package the optical sensing module according to the second embodiment of the present invention includes a distance adjustment module 34 , an image analysis module 36 , a packaging module 31 and a base 38 . The distance adjustment module 34 , the encapsulation module 31 and the base 38 all have the same functions as those mentioned above, but the image analysis module 36 has the function of contamination detection in addition to the functions mentioned above.

Please refer to FIG. 4 , which is a block diagram of a packaging device 40 capable of selecting an optimal distance to package an optical sensing module according to a second embodiment of the present invention. The packaging device 40 includes a lens 14 , an optical sensor 16 , a base 38 , a motor 44 , a signal conversion interface 46 and a processor 48 . Base 38 places lens 14 and optical sensor 16 at an adjustable distance. The image signal received by the optical sensor 16 is transmitted to the signal conversion interface 46 . The signal conversion interface 46 stores or transmits the video signal to the processor 48 . The processor 48 is used to analyze and process the image signal, and send the analysis result back to the signal conversion interface 46 . The motor 44 is used to adjust the distance between the lens 14 and the optical sensor 16 . The signal conversion interface 46 controls the rotation of the motor 44 according to the analysis result of the processor 48, so that the lens 14 and the optical sensor 16 are separated by an optimal distance, which is used as the packaging distance. Please refer to Figure 5. FIG. 5 is a top view of the structure of the base 38 in the packaging device of the present invention. The base 38 in Fig. 5 comprises a flip cover 39, after the flip cover 39 is opened, the lens 14 and the optical sensor 16 are placed therein, the flip cover 39 is used to fix or protect the lens 14 and the optical sensor 16, so that the packaging device 40 The encapsulation process can be successfully completed.

Please refer to FIG. 6 , which is a flowchart of a method for inspecting a lens or an optical sensor of the present invention. In step 100, an image signal imaged on the optical sensor through the lens is received. Step 110 divides the image signal into a plurality of sub-image signals, the plurality of sub-image signals represent each pixel signal on the optical sensor, and each pixel signal corresponds to a position on the optical sensor. Step 120 compares the plurality of sub-image signals with a standard image, wherein the standard image is a perfect reference image as described above, which is a sample received by a set of perfect (no contamination) lenses and optical sensors The image signal obtained by the light source. The standard image is also decomposed into a plurality of sub-standard images, and each sub-standard image corresponds to a position of the optical sensor. When the comparison is performed in step 120, the plurality of sub-image signals corresponding to the same position are compared one by one with the plurality of sub-standard images . In step 130, if the comparison in step 120 is found to be inconsistent, find out the corresponding position of the sub-image signal that does not match, and deduce the position of the stain on the optical sensor or lens. The sequence of the flow in FIG. 6 is a preferred embodiment of the method of the present invention, and the sequence of the flow can be changed according to the situation, and is not limited to the sequence described.

Please refer to FIG. 7 . FIG. 7 is a flowchart of a method for determining an optimal packaging distance between a lens and an optical sensor in an optical sensing module according to the present invention. Firstly, in step 200 , the distance between the lens and the optical sensor is adjusted to a fixed distance. The process of adjusting the distance is as mentioned above, which is to search successively with different adjustment ranges to obtain a more accurate optimum distance. Then in step 210, the image signal received by the optical sensor is read. In step 220, a part of the image signal is extracted from the image signal received by the optical sensor for subsequent image analysis. If the area is too large, it may cover objects with different depths of field, making it difficult to focus. Step 230 calculates the image difference coefficient according to the partial image signals captured in step 220 . As mentioned above, the image difference coefficient is used to evaluate the clarity of an image signal. If the image difference coefficient of an image is larger, it means that the image is clearer. The calculation of the image difference coefficient in step 230 carries out the following steps:

(a) In this part of the image signal, the difference between each adjacent partial image signal on the horizontal axis is represented by Gx=g(x, y)-g(x+1, y), where g(x, y) For the coordinate position corresponding to ColorFilter being Gb (or Gr) in the partial image, calculate the square Gx ² of the partial image signal difference;

(b) In this part of the image signal, the difference value of each adjacent partial image signal on the vertical axis is represented by Gy=g(x, y)-g(x, y+1), and the difference value of the partial image signal is calculated square Gy ² ;

(c) Adding the squares Gx ² of all local image signal differences on the horizontal axis and the squares Gy ² of all the local image signal differences on the vertical axis to obtain the image difference coefficient.

In step 240, it is judged whether the number of image differences calculated in step 230 starts to decrease and is less than a degree, and the adjustment range is changed and the reverse search is performed; otherwise, steps 210, 220 and 230 are repeated in the same direction and adjustment range. Process, until the maximum image difference value is found with the smallest adjustment range, stop adjusting the distance between the lens and the optical sensor, and fix the distance between the lens and the optical sensor to the maximum value of the image difference coefficient . Once the optimal distance is found, step 250 packages the lens and the optical sensor into an optical sensing module, ie all steps are completed. The sequence of the flow in FIG. 7 is a preferred embodiment of the method of the present invention, and the sequence of the flow can be changed according to the situation, and is not limited to the sequence described.

The above descriptions are only preferred embodiments of the present invention. All equivalent changes and modifications made according to the claims of the present invention shall fall within the scope of the patent of the present invention.

Claims (9)

1. A packaging device capable of selecting an optimal distance to package an optical sensing module, characterized in that it comprises: A base for placing a lens and an optical sensor, the base also includes an adjustment mechanism for adjusting the distance between the lens and the optical sensor; An image analysis module, used to analyze the image signal received by the optical sensor and output an analysis result signal according to the analysis result; A distance adjustment module, connected to the base and the image analysis module, is used to control the adjustment mechanism of the base to adjust the distance between the lens and the optical sensor according to the analysis result signal output by the image analysis module; and A packaging module is used to package the lens and the optical sensor to form the optical sensing module. 2. The packaging device as claimed in claim 1, wherein the distance adjusting module comprises a motor. 3. The packaging device as claimed in claim 1, wherein the image analysis module comprises a stain detection circuit for judging whether the lens or the optical sensor is stained according to the image signal received by the optical sensor and a standard image . 4. The packaging device according to claim 1, further comprising a stain detection module connected to the base for judging the lens or the optical sensor according to the image signal received by the optical sensor and a standard image Whether it is defaced. 5. The packaging device of claim 4, wherein the blemish detection module comprises a memory for storing the standard image. 6. The packaging device as claimed in claim 1, further comprising a memory disposed in the image analysis module for storing the image signal received by the optical sensor. 7. A method for packaging the optical sensing module with an optimal packaging distance between a lens and an optical sensor in the optical sensing module, characterized in that it comprises the following steps: (a) read the image signal received by the optical sensor; (b) the image analysis module extracts a part of the image signal from the image signal received by the optical sensor; (c) The image analysis module calculates the image difference coefficient according to the captured part of the image signal, and the calculation of the image difference coefficient performs the following steps: (c1) in the partial image signal, calculate the square of the difference between each adjacent partial image signal on the horizontal axis; (c2) of the partial image signal, calculate the square of the difference between adjacent partial image signals on the vertical axis; and (c3) adding the square of each image signal difference on the horizontal axis to the square of each image signal difference on the vertical axis to obtain the image difference coefficient; (d) The distance adjustment module controls the adjustment mechanism to adjust the distance between the lens and the optical sensor according to the image difference coefficient, and the step (d) adjusts the distance between the lens and the optical sensor so that the lens and the optical sensor are within At this distance, the image difference coefficient calculated from the captured part of the image signal is the largest; (e) fixing the lens and the optical sensor by the packaging module and completing the packaging of the optical sensing module. 8. The method according to claim 7, wherein the step (d) of adjusting the distance between the lens and the optical sensor comprises a plurality of adjustment processes, and each adjustment range is different. 9. The method according to claim 7, further comprising a detection step between steps (a) and (b), using a stain detection module or a stain detection circuit to detect a lens or an optical sensor ,Include: (a) receiving an image signal imaged on the optical sensor through the lens; (b) dividing the image signal into a plurality of sub-image signals, and the plurality of sub-image signals correspond to a plurality of positions respectively; (c) comparing the plurality of sub-image signals with the plurality of sub-standard images of the standard image; (d) When the image signal does not match the standard image, determine the position of the inconsistent sub-image signal.

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