TWI737582B - Camera and inspection device - Google Patents

Abstract

The present invention provides an imaging device capable of performing corrections corresponding to a plurality of imaging conditions. The camera device includes: a camera mechanism, which obtains image data of the subject; a memory mechanism, which stores a plurality of correction data, and the correction data is used to correct at least one of the aforementioned camera mechanism and the aforementioned image data; and a correction mechanism, Switching the plurality of calibration data to perform calibration of at least one of the imaging mechanism and the image data.

Description

Camera and inspection device Field of invention

The present invention relates to an imaging device and an inspection device with a correction mechanism, in particular to an imaging device and an inspection device with a shadow correction mechanism.

Background of the invention

For the inspection device that inspects foreign objects or scars on the surface of the inspected object based on the image data obtained by imaging the inspected object, there is an inspection device that is synchronized with the imaging sequence and sequentially switches the plural To capture images with a single illumination (for example, refer to Patent Document 1).

In addition, in recent years, a technique has been reviewed to correct the uneven brightness of image data obtained by an imaging device using an imaging element such as CCD or CMOS. For example, a technique for correcting the unevenness of the sensitivity of the imaging element or the illumination, and the unevenness of the brightness of the lens, etc., is known as shading correction (for example, refer to Patent Document 2). The shadow correction is a technique for correcting the difference in the sensitivity characteristics of each pixel of the strip sensor. According to the white reference data and the black reference data, the image data is subjected to specification processing, thereby correcting the sensitivity difference of each pixel. For this reason, in the shadow correction, each strip sensor (R, Each pixel of G and B) holds white reference data and black reference data.

Furthermore, there is also a data processing circuit including three shading correction circuits for each color of RGB for the use of the color stripe sensor (for example, refer to Patent Document 3).

Advanced technology Patent literature

Patent Document 1: Japanese Patent Application Publication No. 2012-42297

Patent Document 2: Japanese Patent Application Publication No. H8-307672

Patent Document 3: Japanese Patent Application Publication No. 2009-94928

Summary of the invention

In the above-mentioned shading correction technology, for the three RGB imaging elements, the correction data for the respective RGB imaging elements are held, but the correction data is the correction data under specific lighting conditions, and does not have multiple lighting conditions for each Correct the information.

However, if the lighting conditions during shooting are different, the data used for shadow correction will also change. For this reason, it is difficult to perform correct shadow correction with only the correction data under one scanning condition when switching between multiple lighting conditions for recording, etc.

The object of the present invention is to provide an imaging device that can perform corrections corresponding to a plurality of imaging conditions.

The imaging device of the present invention is characterized by comprising: an imaging mechanism to obtain image data of an object to be captured; a memory mechanism to store a plurality of correction data, and the correction data is used to correct at least one of the imaging mechanism and the image data One; and a correction mechanism that switches the plurality of correction data to perform correction of at least one of the imaging mechanism and the image data.

According to the imaging device of the present invention, at least one of the imaging mechanism and the image data can be calibrated by the calibration data corresponding to the imaging conditions, so that proper calibration corresponding to the imaging conditions can be performed.

1,11‧‧‧Camera mechanism

1a,11a‧‧‧Camera element

1b,11b‧‧‧Camera control mechanism

2,12‧‧‧Memory Mechanism

2a‧‧‧The first calibration data

2b‧‧‧Second calibration data

2c‧‧‧The third calibration data

2d‧‧‧Fourth calibration data

3‧‧‧Correction mechanism

4,14‧‧‧Output mechanism

5‧‧‧The object to be photographed, the object to be inspected

10,10a,10b,10c,10d‧‧‧Camera device

12a‧‧‧The first shadow correction data

12b‧‧‧Second shadow correction data

12c‧‧‧The third shadow correction data

12d‧‧‧Fourth shadow correction data

13‧‧‧Shadow Correction Mechanism

15‧‧‧Lens

16‧‧‧Synchronization signal generating mechanism

17‧‧‧Lighting control mechanism

18a, 18b, 18c, 18d‧‧‧lighting

19‧‧‧Transportation agency

20,20a,20b‧‧‧Control device

22a, 22b, 22c ‧ ‧ strip memory

25‧‧‧Inspection agency

30‧‧‧Camera system with lighting

40,40a,40b‧‧‧Inspection device

Fig. 1 is a block diagram showing the structure of the imaging device of the first embodiment.

Fig. 2 is a block diagram showing the structure of an imaging system with illumination including the imaging device of the second embodiment.

Fig. 3 is a schematic diagram showing the operation of the shadow correction mechanism of the imaging device of Fig. 2.

Fig. 4 is a line diagram showing the white reference and black reference of each pixel constituting the shading correction data, the image signal before correction, and the image signal after correction.

Fig. 5 is a flow chart of a camera method. The camera method is a method of correcting and obtaining corrected image data in a switchable camera in which _{m max illuminations are sequentially switched to perform the camera.}

Fig. 6 is a block diagram showing the structure of the inspection device of the third embodiment.

Fig. 7 is a block diagram showing the structure of the inspection device of the fourth embodiment.

Fig. 8 is a block diagram showing the structure of the inspection device of the fifth embodiment.

Detailed description of the preferred embodiment

The imaging device of the first aspect is characterized by comprising: an imaging mechanism to obtain image data of the subject; a memory mechanism to store a plurality of correction data, the correction data being used to correct the imaging mechanism and the image data At least one of; and a calibration mechanism, which switches the plurality of calibration data to perform calibration of at least one of the camera mechanism and the image data.

In the imaging device of the second aspect, in the above-mentioned first aspect, the correction data may be shadow correction data for shadow correction of the image data.

In this case, the aforementioned correction mechanism may also be a shadow correction mechanism that uses the aforementioned shadow correction data to perform shadow correction.

In the imaging device of the third aspect, in the above-mentioned first aspect, the calibration data may also be calibration data related to the storage time of the imaging element in the imaging mechanism.

At this time, the calibration mechanism may also be a mechanism that uses calibration data related to the storage time to adjust the storage time of the imaging element in the imaging mechanism.

In the imaging device of the fourth aspect, in the above-mentioned first aspect, the calibration data may also be calibration data related to the gain in the imaging mechanism.

At this time, the aforementioned correction mechanism may also be a mechanism that uses correction data related to the aforementioned gain to adjust the gain in the aforementioned imaging mechanism.

In the imaging device of the fifth aspect, in any one of the above-mentioned first to fourth aspects, the aforementioned calibration data may also be calibration data for calibration corresponding to the lighting conditions at the time of imaging.

At this time, the correction mechanism can also perform correction by switching from the plurality of correction data to the correction data corresponding to the lighting conditions during the shooting in response to the switching of the lighting conditions during the shooting.

With the above configuration, it is possible to perform calibration using calibration data corresponding to each lighting condition. In addition, the correction is performed inside the imaging device, so that it will not be affected by the low-level processing when outputting to the outside, and high-precision correction processing based on the high-level image signal can be performed.

In the imaging device of the sixth aspect, in the fifth aspect, the calibration mechanism may be synchronized with the switching of the lighting conditions during imaging, and switch to calibration data corresponding to the lighting conditions during imaging.

With the above configuration, the calibration data is switched in synchronization with the switching of the lighting conditions, so that the calibration corresponding to each lighting condition can be performed in sequence.

In the imaging device of the seventh aspect, in the above-mentioned first aspect, the calibration mechanism may be synchronized with the imaging in the imaging mechanism to switch the calibration data.

The imaging device of the eighth aspect, in the above-mentioned first aspect, may also include an output mechanism that performs low-level processing on the image signal of the corrected image data and outputs it to the outside.

The inspection device of the ninth aspect includes the aforementioned imaging device in any one of the above-mentioned first to eighth aspects.

The inspection device of the tenth aspect is characterized in that it includes: lighting A mechanism that can switch a plurality of different lighting conditions for the inspection object to illuminate; the imaging mechanism obtains the image data of the inspection object illuminated by the lighting mechanism; the memory mechanism stores a plurality of calibration data, the calibration data is Used to calibrate at least one of the aforementioned imaging mechanism and the aforementioned image data corresponding to the aforementioned plural lighting conditions; the correction mechanism, corresponding to the switching of the illumination conditions during imaging, switch the aforementioned plural correction data, and perform the aforementioned imaging mechanism and the aforementioned image Correction of at least one of the data; and the inspection agency, based on the corrected image data, conducts the inspection of the aforementioned object to be inspected.

In the inspection device of the eleventh aspect, in the above-mentioned tenth aspect, the lighting mechanism may have a plurality of lighting devices that perform lighting under different lighting conditions.

In the inspection device of the twelfth aspect, in the tenth or eleventh aspect, the correction data may also be shadow correction data for shadow correction of the image data.

In this case, the aforementioned correction mechanism may also be a shadow correction mechanism that uses the aforementioned shadow correction data to perform shadow correction.

In the inspection device of the 13th aspect, in the 10th or 11th aspect, the calibration data may also be calibration data related to the storage time of the imaging element in the imaging mechanism.

At this time, the aforementioned calibration mechanism can also be used in relation to the aforementioned storage time The calibration data is a mechanism for adjusting the storage time of the imaging element in the aforementioned imaging mechanism.

In the inspection device of the fourteenth aspect, in any one of the tenth or eleventh aspects, the calibration data may also be calibration data related to the gain in the imaging mechanism.

At this time, the aforementioned correction mechanism may also be a mechanism that uses correction data related to the aforementioned gain to adjust the gain in the aforementioned imaging mechanism.

In the inspection device of the fifteenth aspect, in any one of the tenth to fourteenth aspects, the correction mechanism may be synchronized with the switching of the lighting conditions during imaging, and switch to correspond to the lighting conditions during imaging The calibration data.

With the above configuration, the calibration data can be switched in synchronization with the switching of the lighting conditions, and the calibration corresponding to each lighting condition can be executed in sequence.

In the inspection device of the sixteenth aspect, in any one of the tenth to fifteenth aspects, the calibration mechanism may be synchronized with the imaging in the imaging mechanism to switch the calibration data.

Hereinafter, an imaging device and an inspection device according to an embodiment of the present invention will be described with reference to the drawings. In addition, in the figures, the same reference numerals are attached to substantially the same members.

(Embodiment 1)

<Camera Device>

Fig. 1 is a block diagram showing the structure of an imaging device 10 according to the first embodiment. The camera device 10 includes: a camera mechanism 1, which obtains image data of the object 5; a memory mechanism 2, which stores correction data 2a, 2b, 2c, 2d, and The positive data 2a, 2b, 2c, and 2d are used to calibrate at least one of the imaging mechanism 1 and the image data; and the calibration mechanism 3 uses the calibration data to calibrate at least one of the imaging mechanism 1 and the image data. In addition, it may also include an output mechanism 4 for outputting the image signal of the corrected image data to the outside.

In this imaging device, at least one of the imaging mechanism 1 and the image data can be calibrated by the calibration data corresponding to the imaging conditions, so that appropriate corrections corresponding to the imaging conditions can be performed. In addition, the imaging device 10 includes a memory mechanism 2 with calibration data 2a, 2b, 2c, and 2d, and a calibration mechanism 3. Therefore, compared with the form of outputting to external processing, it will not be lowered by external output. The effect of the color gradation processing can be corrected in the original state of the high-precision image data (high-color gradation image signal) inside the imaging device 10, and the image data that has been calibrated with high precision can be obtained.

Hereinafter, each component constituting the imaging device 10 will be described.

<Camera Mechanism>

The imaging mechanism 1 may also include an imaging element 1a such as CCD and CMOS, and an imaging control mechanism 1b that controls the imaging element 1a. In addition, the imaging mechanism 1 may be either a strip sensor or a block sensor. For example, when the imaged object 5 is transported, a strip sensor can also be used for high-speed scanning in the transport direction. The strip sensor can also be a single monochrome strip sensor.

<Memory Mechanism>

The memory mechanism 2 has a plurality of calibration data 2a, 2b, 2c, and 2d. The calibration data 2a, 2b, 2c, and 2d are used to calibrate the camera mechanism 1 and the image data. One less. Taking the correction data 2a, 2b, 2c, and 2d as an example, it may also be shading correction data. Or, the calibration data can also be calibration data used to adjust the overall brightness of the image, for example, calibration data related to the storage time of the imaging element 1a in the imaging mechanism 1. In addition, the calibration data may also be calibration data related to the gain in the imaging mechanism 1. In addition, the form in which the correction data is shading correction data is described in detail in the second embodiment.

<Correction Mechanism>

By means of the calibration mechanism 3, the calibration data is used to calibrate at least one of the camera mechanism 1 and the image data. The correction mechanism 3 can also be implemented as a physical structure by using electrical circuits, for example. Or, it can also be implemented by computer software that runs on the computer. The computer only needs to have the minimum functions necessary to perform the above-mentioned correction actions among the usual constituent elements, such as CPU, ROM, RAM, hard disk, and input/output interface.

In addition, when the calibration data is related to the storage time of the imaging element in the imaging mechanism 1, the calibration mechanism 3 can change the storage time of the imaging element of the imaging mechanism 1 based on the calibration data to perform exposure and imaging. Get image data. In fact, the calibration mechanism 3 reads any of the calibration data 2a, 2b, 2c, 2d related to the storage time from the memory mechanism 2, and sets the value in the imaging mechanism 1, thereby changing the imaging element 1a Storage time.

When the calibration data is the calibration data related to the gain in the camera mechanism 1, the gain of the camera mechanism 1 (analog gain or digital gain) is changed according to the calibration data by the calibration mechanism 3 to perform exposure and shooting. Get image data. In fact, the correction mechanism 3 reads and increases from the memory mechanism 2. For any one of the calibration data 2a, 2b, 2c, 2d related to the setting value, set the value in the imaging mechanism 1 to change the gain.

In addition, the calibration mechanism 3 can also be synchronized with the imaging of the imaging mechanism 1 to switch calibration data.

<Output mechanism>

Through the output mechanism 4, the image signal of the corrected image data is output to the outside.

In addition, when the transmission rate of the output mechanism 4 is limited when outputting to the outside, there is a form in which the image signal is subjected to low-level processing and then output to the outside. At this time, it is necessary to reduce the accuracy of the high-precision image signal and output it.

In the imaging device 10, as described above, it will not be affected by the low-level processing when outputting to the outside, and can be performed in the original state of the high-precision image data (high-level image signal) inside the imaging device 10 Correction can obtain high-precision corrected image data. In addition, because the corrected image data after output to the outside is processed by low-level processing, it will not be affected by low-level processing, such as large Decrease in the number of digits, etc., so the impact of decreased accuracy can be suppressed.

<Buffer memory>

In the imaging device 10, a buffer memory may be provided between the imaging mechanism 1 and the correction mechanism 3. The buffer memory can hold the image signal from the camera 1 for a period of time. In this way, when the timing of shooting cannot be synchronized with the timing of correction, the image data before correction can also be held within a predetermined period.

(Embodiment 2)

<Camera Device>

2 is a block diagram showing the structure of an imaging system 30 with illumination including the imaging device 10a of the second embodiment. The imaging device 10a includes: an imaging mechanism 11 to obtain image data of the subject 5; a memory mechanism 12 to store shadow correction data 12a, 12b, 12c, 12d, and the aforementioned shadow correction data 12a, 12b, 12c, 12d are used Perform shadow correction on the image data; and the shadow correction mechanism 13 uses the shadow correction data 12a, 12b, 12c, and 12d to perform shadow correction on the image data. In addition, it may also have an output mechanism 14 for outputting the image signal of the corrected image data to the outside.

In this imaging device 10a, the image data can be subjected to shading correction based on the shading correction data corresponding to the lighting conditions at the time of shooting, so that appropriate corrections corresponding to the imaging conditions can be performed. In addition, the imaging device 10a includes a memory mechanism 12 and a shadow correction mechanism 13 having shadow correction data 12a, 12b, 12c, and 12d. Here, compared with the form of processing after outputting to the outside, it will not be affected by the low-level processing when outputting to the outside. High-precision image data (high-level image signal ) Perform shadow correction in the original state to obtain high-precision corrected image data.

Hereinafter, each component constituting the imaging device 10a will be described.

<Camera Mechanism>

The imaging mechanism 11 can be substantially the same as the imaging device 1 of the first embodiment. Therefore, detailed description is omitted.

In addition, in FIG. 2, the lens 15 and the imaging mechanism 11 are displayed separately, but this is only to show the imaging state of the imaging from approximately directly above. The lens 15 and the camera mechanism 11 are displayed separately. In addition, the lens 15 may also be included in the imaging mechanism 11. In addition, in FIG. 2 the imaging device is shown as an integrated object, for example, it may be a head-separated structure (the imaging mechanism 11 and the lens 15 are regarded as the head, and the processing located at the back of the head The part should be regarded as a separate structure of the controller part).

<Memory Mechanism>

The memory mechanism 12 has a plurality of shading correction data 12a, 12b, 12c, and 12d. The shading correction data 12a, 12b, 12c, and 12d are composed of the white reference and the black reference of each pixel of the imaging element 11a of the imaging mechanism 11 for each lighting condition. For example, FIG. 4 is a line diagram showing the white reference W and the black reference B of each pixel constituting the shading correction data. The horizontal axis of FIG. 4 represents the pixel position, and the vertical axis represents the brightness.

In addition, the first shadow correction data 12a, the second shadow correction data 12b, the third shadow correction data 12c, and the fourth shadow correction data 12d correspond to lighting L1 (18a), lighting L2 (18b), lighting L3 (18c), and Illumination L4 (18d) lighting conditions. In addition, it is not necessary to make the number of lighting and the number of shadow correction data consistent, as long as the required number of shadow correction data corresponding to the combination of various lighting conditions is memorized, and then corresponding to the switching of the lighting conditions, use the appropriate shadow correction Information, that's it.

The white reference W of each pixel constituting the shading correction data can be obtained by shooting with a white correction plate for each illumination. Or, there is also a form in which the white reference W is obtained by directly irradiating the imaging element 11a of the imaging mechanism 11 from each illumination. The black reference B can be captured in a state where no light enters the imaging element 11a of the imaging mechanism 11, for example, with the lens 15 covered. or, As with the white reference W, the black reference B may be obtained by imaging using a black calibration plate for each illumination. In addition, the black reference B can also be used as data common to all the illuminations 18a, 18b, 18c, and 18d.

<Shadow Correction Mechanism>

The shadow correction mechanism 13 uses shadow correction data to perform shadow correction on the image data. The shadow correction mechanism 13, for example, can also be implemented by using electrical circuits as a physical structure. Or, it can also be implemented by computer software that runs on the computer. The computer only needs to have the minimum necessary functions for performing the above-mentioned correction actions among the usual constituent elements, namely, CPU, ROM, RAM, hard disk, input and output interface, etc.

In addition, when the shadow correction mechanism 13 is configured as an electric circuit, a plurality of shadow correction circuits set for each lighting condition are switched in synchronization with the lighting of imaging and lighting, so that there is no need to switch the lighting every time. The memory mechanism 12 reads the time when the shading correction data 12a, 12b, 12c, and 12d are read, so that higher-speed correction processing can be performed.

FIG. 3 is a schematic diagram showing the operation of the shadow correction mechanism 13 of the imaging device 10a of FIG. 2. Fig. 4 is a line diagram showing that the white reference Wi and the black reference Bi of each pixel i constituting a shading correction data are respectively used as elements in all pixels, and the white reference W and the black reference B are included, and each pixel i is ordered in all pixels. The image signal Si before correction is used as an element and the image signal S before correction is included, and the image signal S'i after correction for each pixel i is used as an element and the image signal after correction is included in all pixels. Like an example of signal S'.

The following is a description of the shadow correction performed by the shadow correction agency 13 bright.

(a) The shadow correction mechanism 13 stores the image signal S, the white reference W and the black reference B constituting the shadow correction data corresponding to the lighting conditions as the imaging conditions in the strip memories 22a, 22b, and 22c, respectively.

(b) Next, calculate the difference between the white reference Wi and the black reference Bi (Wi-Bi) and the difference between the image signal Si and the black reference Bi (Si-Bi) for each pixel i.

(c) After that, for each pixel i, the difference between the white reference Wi and the black reference Bi (Wi-Bi) is divided by the difference between the image signal Si and the black reference Bi (Si-Bi), and then the specification processing is performed The value of (Si-Bi)/(Wi-Bi).

(d) The value (Si-Bi)/(Wi-Bi)*(2 ^{n -1) of the maximum value 2 n} -1 of the n-bit image signal Si multiplied by the value processed by the specification as the correction The image signal S'i is output.

As above, shadow correction can be performed corresponding to the lighting conditions.

<Output mechanism>

The output mechanism 14 can be substantially the same as the output mechanism 4 in the first embodiment. Here, detailed description is omitted.

<Buffer memory>

The buffer memory can be substantially the same as the buffer memory in the first embodiment. Here, detailed description is omitted.

<Camera system with lighting>

The camera system 30 with illumination includes the camera device 10a of the second embodiment, the synchronization signal generating mechanism 16, the illumination control mechanism 17, and the illumination 18a, 18b, 18c, and 18d. The camera system 30 with illumination, as described in Japanese Patent Application Publication No. 2012-42297, can be combined with the camera mechanism 11 The imaging timing is synchronized, and the multiple illuminations 18a, 18b, 18c, and 18d are switched while imaging, which is driven in a so-called switching imaging mode.

In addition, the camera system 30 with illumination can also be driven without synchronizing the camera timing of the camera mechanism 11 with the switching of the plurality of illuminations 18a, 18b, 18c, and 18d. Therefore, the synchronization of the camera timing and the switching of the illumination is not necessary. .

Hereinafter, each component constituting the imaging system 30 with illumination will be described.

<Camera Device>

As the imaging device 10a, the above-mentioned imaging device 10a can be used, so the description is omitted.

<Lighting>

The imaging system 30 with illumination includes illumination L1 (18a), illumination L2 (18b), illumination L3 (18c), and illumination L4 (18d) that become regular reflected light. In addition, illumination L1 (18a), illumination L2 (18b), and illumination L3 (18c) illuminate red (R), green (G), and blue (B) corresponding to R, G, and B respectively, and illumination L4 (18d) ) Is to irradiate white light.

In addition, the number of illuminations 18a, 18b, 18c, and 18d is not limited to four types. For example, the number of lighting may be one, two, three, or five or more. In addition, in the above example, it is a combination of three types of diffuse reflection light and one type of forward reflection light, but it is not limited to this. For example, the transmitted light may be further combined.

<Synchronization Signal Generator>

The synchronization signal generating mechanism 16 transmits synchronization signals to the imaging mechanism 11, the shadow correction mechanism 13, and the lighting control mechanism 17, so that the lighting 18a, 18b, The switching of 18c and 18d is synchronized with the timing of shooting. In addition, after the recording is finished, the switching to the next illumination is synchronized with the shadow correction for the image signal captured by the previous illumination. Therefore, the switching of the illuminations 18a, 18b, 18c, and 18d and the reading of the shadow correction data 12a, 12b, 12c, and 12d corresponding to the previous illumination are synchronized.

In addition, the synchronization signal generating mechanism 16 may also be provided in either the imaging device 10 a or the lighting control mechanism 17. Or it can be set separately in another body.

<Lighting Control Mechanism>

The lighting control mechanism 17 controls the lighting 18a, 18b, 18c, and 18d. The lighting control mechanism 17 sequentially switches the lighting 18a, 18b, 18c, and 18d according to the aforementioned synchronization signal. In addition, the lighting control in switchable imaging is not limited to switching multiple lightings in sequence. For example, two or more lightings can be combined to irradiate at the same time, and one lighting can be irradiated several times while switching the wavelength or brightness. .

<Transportation Organization>

The transport mechanism 19 may, for example, transport the object 5 in a single direction. Taking the conveying mechanism 19 as an example, it may be a belt conveyer, for example.

<Camera method>

Fig. 5 is a flow chart of a camera method. The camera method is a method of correcting and obtaining corrected image data in a switchable camera in which _{m max illuminations are sequentially switched to perform the camera.}

(1) First, store the correction data, storage time, and gain for each shadow of each lighting in the memory mechanism (S01). In addition, the acquisition of the shading correction data corresponding to each illumination, as described above, is to obtain the white reference and the black reference corresponding to each illumination. Regarding the storage time and gain, the brightness of each lighting is also obtained. The relationship between degree, storage time and gain, so as to obtain calibration data.

(2) For the initial setting, it is set to n=1 and m=1 (S02).

(3) Start the n-th imaging (S03).

(4) Set the storage time and gain based on the m-th calibration data (S04). For example, when the illumination is too bright due to the forward reflected light, etc., reduce the storage time of the imaging element 11a of the imaging mechanism 11 or reduce the gain. Conversely, when it is too dark due to the penetrating light, etc., the imaging element can also be added. The storage time of 11a may increase the gain.

(5) Turn on the m-th illumination (S05).

(6) Perform exposure and take a picture to obtain an image signal (S06).

(7) Turn off the m-th illumination (S07).

(8) Perform shading correction on the image signal with the m-th correction data (shading correction data) and output it (S08).

(9) Determine whether the number m of the lighting is m _max (S09). When it is m _max , reset the number m of the lighting to 1 (S10). When it is not m _max , increase m (m=m+1) ( S11), go back to step S04. In addition, the resetting of the lighting number m (S10) is not limited to the form performed at this stage. For example, it is also possible to reset the number of lighting to m at the same time when the n-th shooting (S03) is started.

(10) After resetting the lighting number m to 1, when the online number n is n _max , it is judged whether it is n _max (S12), and _{when it is n max} , the imaging is ended. When the number n of the line is not n _max , n is increased (n=n+1) (S13), and the process returns to step S03.

With the above steps, switch the _{camera after switching m max} illuminations in sequence, use the correction data (shadow correction data, storage time, gain) corresponding to each lighting condition, and combine the camera mechanism and the image data At least one is corrected to obtain corrected image data.

According to the above-mentioned imaging method, the unevenness of the sensitivity per pixel of the imaging mechanism 11 such as the strip sensor and the unevenness of the illumination caused by the difference in the lighting conditions can be simultaneously corrected in the interior of the imaging device 10a.

In addition, in the above-mentioned imaging method, the form of correction of shadow correction, storage time, and gain is explained, but it is not necessary to correct all of them. It can also be corrected for one of shadow correction, storage time, gain, or a combination of these.

(Embodiment 3)

<Checking device>

Fig. 6 is a block diagram showing the structure of the inspection device 40 of the third embodiment. The inspection device 40 includes: an imaging device 10b, a synchronization signal generating mechanism 16, a lighting control mechanism 17, a plurality of lighting devices 18a, 18b, 18c, 18d, and a control device 20. The inspection device 40, as described in Japanese Patent Application Publication No. 2012-42297, can be switched by the synchronization signal generated by the synchronization signal generating mechanism 16 with the timing of the imaging mechanism 1 in the imaging device 10b. The illumination conditions of the plurality of illuminators 18a, 18b, 18c, and 18d are driven while imaging, which is a so-called switching imaging method. The plurality of lightings 18a, 18b, 18c, and 18d can be controlled by the lighting control mechanism 17.

The inspection device 40 includes a memory mechanism 2 that stores calibration data 2a, 2b, 2c, 2d, and the calibration data 2a, 2b, 2c, 2d are used to calibrate at least one of the imaging mechanism 1 and image data. Corresponding to each lighting condition; and calibration mechanism 3, using calibration data, calibration camera mechanism 1 At least one of image data. In this way, at least one of the imaging mechanism 1 and the image data can be calibrated by the calibration data corresponding to the lighting conditions, so that proper calibration corresponding to the lighting conditions can be performed.

The memory mechanism 2 and the correction mechanism 3 described above are included in the control device 20, but are not limited to this. For example, as shown in the second embodiment, it may be included in the imaging device 10b. In addition, the control device 20 has an inspection mechanism 25 that performs inspection of the inspection object based on the corrected image data.

In addition, the inspection device 40 can also be driven without the need to synchronize the switching of the imaging timing of the imaging mechanism 1 in the imaging device 10b with the switching of the lighting conditions of the plurality of illuminations 18a, 18b, 18c, and 18d, and the switching of the imaging timing and lighting conditions is synchronized. Not a necessary composition.

<Camera Device>

The imaging device 10b includes an imaging mechanism 1 that obtains image data of the object to be inspected. In addition, an output mechanism 4 for outputting the image signal of the image data to the outside after low-level processing of the image data can also be provided.

<Camera Mechanism>

The imaging mechanism 1 may also include an imaging element 1a such as CCD and CMOS, and an imaging control mechanism 1b that controls the imaging element 1a. In addition, the imaging mechanism 1 may also be a line sensor or an area sensor. For example, when the inspection object is being transported, in order to perform high-speed scanning in the transport direction, a strip-shaped sensor can also be used. The strip sensor can also be a single monochromatic strip sensor.

In addition, in FIG. 1, the lens 15 is displayed separately from the imaging mechanism 1, but this is just to show the imaging state of the imaging from approximately directly above. The lens 15 is displayed separately from the camera mechanism 1. In addition, the lens 15 may also be included in the imaging mechanism 1. In addition, in FIG. 1, the imaging device is shown as an integrated object, for example, it can also be a head-separated structure (the imaging mechanism 1 and the lens 15 are regarded as the head, and the processing located at the back of the head The part should be regarded as a separate structure of the controller part).

<Output mechanism>

Through the output mechanism 4, the image signal of the image data is output to the outside of the imaging device 10b.

In addition, when the transmission rate of the output mechanism 4 is limited when outputting to the outside, there is a form of outputting the image signal to the outside through low-level processing. At this time, it is necessary to reduce the accuracy of the high-precision image signal and output it.

<Control device>

The control device 20 includes a memory mechanism 2, a correction mechanism 3, and an inspection mechanism 25. In addition, a buffer memory may be provided between the imaging mechanism 1 and the correction mechanism 3.

<Memory Mechanism>

The memory mechanism 2 has a plurality of calibration data 2a, 2b, 2c, and 2d corresponding to each lighting condition. The calibration data 2a, 2b, 2c, and 2d are used to calibrate at least one of the imaging mechanism 1 and the image data. Taking the correction data 2a, 2b, 2c, and 2d as an example, it may also be shading correction data. Or, the calibration data can also be calibration data used to adjust the overall brightness of the image, for example, calibration data related to the storage time of the imaging element 1a in the imaging mechanism 1. In addition, the calibration data may also be calibration data related to the gain in the imaging mechanism 1. In addition, the form of correction data as shadow correction data is described in detail in Embodiment 4. Of.

<Correction Mechanism>

By means of the calibration mechanism 3, the calibration data is used to calibrate at least one of the camera mechanism 1 and the image data. The correction mechanism 3 can also be implemented as a physical structure by using electrical circuits, for example. Or, it can also be implemented by computer software that runs on the computer. The computer only needs to have the minimum necessary functions for performing the above-mentioned correction actions among the usual constituent elements, namely, CPU, ROM, RAM, hard disk, input and output interface, etc.

In addition, when the calibration data is related to the storage time of the imaging element in the imaging mechanism 1, the calibration mechanism 3 can change the storage time of the imaging element of the imaging mechanism 1 based on the calibration data to perform exposure and imaging. Get image data. In fact, the calibration mechanism 3 reads any of the calibration data 2a, 2b, 2c, 2d related to the storage time from the memory mechanism 2, and sets the value in the imaging mechanism 1, thereby changing the imaging element 1a Storage time.

When the calibration data is the calibration data related to the gain in the camera mechanism 1, the gain of the camera mechanism 1 (analog gain or digital gain) is changed according to the calibration data by the calibration mechanism 3 to perform exposure and shooting. Get image data. In fact, the correction mechanism 3 reads any one of the correction data 2a, 2b, 2c, 2d of the setting value related to the gain from the memory mechanism 2, and sets the value in the imaging mechanism 1, thereby changing the gain.

In addition, the calibration mechanism 3 can also switch the calibration data in synchronization with the switching of the lighting conditions of the lighting 18a, 18b, 18c, and 18d and the imaging of the imaging mechanism 1.

<Inspection Organization>

The inspection mechanism 25 is used to inspect the inspected object 5 based on the corrected image data. For example, for image data, pattern matching techniques can also be used to inspect the shape, pattern, color, etc. of the inspection object 5. In addition, various image processing filters can also be used to capture the defects of the inspected object 5.

In addition, a combination of a plurality of image data captured under different lighting conditions can be inspected, so that it is also possible to inspect defects such as that the image data obtained only under a single lighting condition cannot be judged. For example, a plurality of image data captured by the inspection object 5 with different wavelengths of illumination may be expressed in different colors, and the respective image data may be synthesized to form a color image. Based on the synthesized color image, perform Inspection of the inspected object 5.

In addition, the above-mentioned corrected image data refers to, for example, the correction is related to image data. When the correction of image data such as shading correction, it is "corrected image data". When the correction is the storage time or When calibrating the camera mechanism for gain, it means "image data obtained by the camera mechanism after calibration".

At this time, according to the inspection device 40 of the present invention, the correction data corresponding to the lighting conditions at the time of imaging is used for calibration, so it is easy to combine a plurality of image data captured under different lighting conditions.

<Buffer memory>

In the control device 20, a buffer memory may be provided between the imaging mechanism 1 and the correction mechanism 3. The buffer memory can hold the image signal from the camera 1 for a period of time. In this way, when the timing of shooting cannot be synchronized with the timing of correction, the image data before correction can also be held within a predetermined period.

<Lighting Mechanism>

The lighting mechanism can switch and illuminate the inspected object 5 in a plurality of different lighting conditions. In the inspection device 40, as the lighting mechanism, there are lighting L1 (18a), lighting L2 (18b), lighting L3 (18c), and lighting devices that are forward reflected light. Illumination L4 (18d). In addition, illumination L1 (18a), illumination L2 (18b), and illumination L3 (18c) respectively irradiate red light (R), green light (G), and blue light (B) corresponding to R, G, and B, and illumination L4 ( 18d) Irradiate white light.

In addition, the lighting mechanism is not limited to the four types of lighting 18a, 18b, 18c, and 18d. For example, the number of lighting devices can also be one, two, three, or more than five. In addition, in the above example, a combination of three diffuse reflected lights and one forward reflected light constitutes the lighting mechanism, but it is not limited to this, for example, the transmitted light (not shown in the figure) may be further combined. In addition, for the same diffuse reflection light, diffuse reflection lights with different incident angles may also be provided. By this, it is possible to inspect two kinds of foreign objects that are easy to see when the incident angle is shallow, and those that are easy to see when the incident angle is deep.

<Synchronization Signal Generator>

The synchronization signal generating mechanism 16 transmits synchronization signals to the camera mechanism 1, the calibration mechanism 3, and the lighting control mechanism 17, so that the switching of the lighting conditions of the lighting 18a, 18b, 18c, and 18d is synchronized with the timing of shooting. In addition, after the end of the shooting, the switching to the next lighting is synchronized with the correction of the image signal captured by the previous lighting condition. Therefore, the switching of the lighting 18a, 18b, 18c, and 18d and the reading of the correction data 2a, 2b, 2c, and 2d corresponding to the previous lighting condition are synchronized.

In addition, the synchronization signal generating mechanism 16 may also be provided in any one of the imaging device 10b, the lighting control mechanism 17, and the control device 20. Or it can be set separately in another body.

<Lighting Control Mechanism>

The lighting control mechanism 17 controls the lighting 18a, 18b, 18c, and 18d. The lighting control mechanism 17 sequentially switches the lighting 18a, 18b, 18c, and 18d according to the aforementioned synchronization signal. In addition, the control of lighting conditions in switchable imaging is not limited to switching multiple lightings in sequence. For example, two or more lightings can be combined to irradiate them at the same time, and one lighting can be irradiated while switching the wavelength or brightness. Several times.

In addition, the lighting control mechanism 17 may be provided in either the imaging device 10b or the control device 20. Or it can be set separately in another body.

<Transportation Organization>

The transport mechanism 19 may, for example, transport the inspection object 5 in a single direction. Taking the conveying mechanism 19 as an example, it may be a belt conveyer, for example.

In addition, in the inspection device 40, the transport mechanism 19 is not an essential configuration. For example, when a strip sensor is used as the imaging mechanism 1, the inspection object can be transported in a single direction by the transportation mechanism 19, and the entire inspection object can be imaged. On the other hand, when a block sensor is used as the imaging mechanism 1, the entire inspection object can be imaged in its original state, so the transport mechanism 19 is not required.

<Camera method>

_{In the switching type imaging in which m max} illuminations are sequentially switched to perform imaging, the imaging method of performing correction to obtain corrected image data is substantially the same as the procedure of the imaging method of FIG. 5, so the description is omitted.

In this switchable _{imaging in which m max} illuminations are sequentially switched to perform imaging, the correction data (shadow correction data, storage time, gain) corresponding to each lighting condition is used to calibrate at least one of the imaging mechanism and the image data. Get the corrected image data.

According to the above-mentioned imaging method, it is possible to simultaneously correct the uneven sensitivity of each pixel of the imaging mechanism 1 such as a strip sensor and the uneven illumination caused by the difference in lighting conditions.

In addition, in the above-mentioned imaging method, the form of correcting all the shading correction, storage time, and gain is explained, but it is not necessary to correct all of them. It can also be corrected for one of shadow correction, storage time, gain, or a combination of these.

(Embodiment 4)

Fig. 7 is a block diagram showing the structure of an inspection device 40a of the fourth embodiment. This inspection device 40a is compared with the inspection device 40 of the third embodiment. The difference is that the imaging device 10c has a memory mechanism 2 and a correction mechanism 3 instead of the control device 20 having a memory mechanism 2 and a correction mechanism 3. Specifically, the imaging device 10c includes: a memory mechanism 2 that stores calibration data 2a, 2b, 2c, 2d corresponding to each lighting condition used to calibrate at least one of the imaging mechanism 1 and image data; and a calibration mechanism 3 , Use the calibration data to calibrate at least one of the camera mechanism 1 and the image data.

In this way, the imaging device 10c includes a memory mechanism 2 and a correction mechanism 3 having correction data 2a, 2b, 2c, and 2d corresponding to each lighting condition. Therefore, compared with the form of outputting to external processing, there is no Affected by the low-level processing of the external output, it can be inside the camera device 10c The high-precision image data (high-level image signal) is calibrated in the original state, and the image data that has been calibrated with high precision can be obtained.

In addition, because the subsequent output of the externally corrected image data is low-level processing, it will not be affected by the low-level processing, such as large-scale bit Therefore, it is possible to suppress the influence of the decrease in accuracy.

(Embodiment 5)

<Checking device>

Fig. 8 is a block diagram showing the structure of an inspection device 40b according to the fifth embodiment. This inspection device 40b is compared with the inspection device 40a of the fourth embodiment. The difference is that the imaging device 10d constituting the inspection device 40b includes a memory mechanism 12 that stores the shadow correction data 12a, 12b for shadow correction of the image data. , 12c, 12d, 12e; and, the shadow correction mechanism 13, which uses the shadow correction data 12a, 12b, 12c, 12d, and 12e to perform shadow correction on the image data. In addition, the lighting is different in that the lighting L5 (18e) is further provided as a penetrating light. In addition, the structure other than this is substantially the same as that of the inspection device of the fourth embodiment.

In the inspection device 40b, the image data can be subjected to shadow correction based on the shadow correction data corresponding to the lighting conditions at the time of imaging, so that appropriate corrections corresponding to the lighting conditions can be performed. In addition, the imaging device 10d constituting the inspection device 40b includes therein a memory mechanism 12 and a shadow correction mechanism 13 having shadow correction data 12a, 12b, 12c, 12d, and 12e. Here, compared to the form of outputting to the outside for reprocessing, it will not be affected by the low-level processing when outputting to the outside, and the image with high precision inside the imaging device 10d Shadow correction is performed on the original state of the data (high-level image signal), and high-precision corrected image data can be obtained.

Hereinafter, each component constituting the inspection device 40b will be described.

<Camera Device>

Each component of the imaging device 10d constituting the inspection device 40b will be described.

<Camera Mechanism>

The imaging mechanism 11 can be substantially the same as the imaging mechanism 1 in the third and fourth embodiments. Here, detailed description is omitted.

<Memory Mechanism>

The memory mechanism 12 has a plurality of shading correction data 12a, 12b, 12c, 12d, and 12e. The shading correction data 12a, 12b, 12c, 12d, and 12e are composed of the white reference and the black reference of each pixel of the imaging element 11a of the imaging mechanism 11 for each lighting condition. For example, FIG. 4 is a line diagram showing the white reference W and the black reference B of each pixel constituting the shading correction data. The horizontal axis of FIG. 4 represents the pixel position, and the vertical axis represents the brightness.

In addition, the first shadow correction data 12a, the second shadow correction data 12b, the third shadow correction data 12c, the fourth shadow correction data 12d, and the fifth shadow correction data 12e correspond to illumination L1 (18a) and illumination L2 (18b), respectively. , Illumination conditions of Illumination L3 (18c), Illumination L4 (18d), Illumination L5 (18e). In addition, there is no need to match the number of lighting with the number of shadow correction data, as long as the required number of shadow correction data corresponding to the combination of various lighting conditions is memorized, and then corresponding to the switching of the lighting conditions, use the appropriate shadow correction Information, that's it.

The white reference W of each pixel that constitutes the shadow correction data can be obtained by shooting with a white correction plate for each illumination. Or, there is also a form in which the white reference W is obtained by directly irradiating the imaging element 11a of the imaging mechanism 11 from each illumination. The black reference B can be captured in a state where no light enters the imaging element 11a of the imaging mechanism 11, for example, with the lens 15 covered. Or, similarly to the white reference W, the black reference B may be obtained by imaging with a black calibration plate for each illumination. In addition, the black reference B can also be used as a common data for all the illuminations 18a, 18b, 18c, 18d, and 18e.

<Shadow Correction Mechanism>

The shading correction mechanism 13 corresponds to the correction mechanism 3 of the third and fourth embodiments. The shadow correction mechanism 13 uses the shadow correction data to perform shadow correction on the image data. The shadow correction mechanism 13 can be implemented as a physical structure with an electrical circuit. Or, it can also be implemented by computer software that runs on the computer. The computer only needs to have the minimum functions necessary to perform the above-mentioned correction actions among the usual constituent elements, such as CPU, ROM, RAM, hard disk, and input/output interface.

In addition, when the shadow correction mechanism 13 is configured as an electric circuit, a plurality of shadow correction circuits set for each lighting condition are switched in synchronization with the lighting of imaging and lighting, so that there is no need to switch the lighting every time. The memory mechanism 12 reads the time when the shading correction data 12a, 12b, 12c, 12d, and 12e are read, so that higher-speed correction processing can be performed.

In addition, the schematic diagram showing the operation of the shadow correction mechanism 13 of the imaging device 10d constituting the inspection device 40b is the same as that of FIG. 3. In addition, the white reference of each pixel constituting the shading correction data in the inspection device 40b is displayed, The line graphs of the black reference, the image signal before correction, and the image signal after correction are the same as those shown in Figure 4. Here, the description of the shading correction by the shading correction mechanism 13 is also the same as the above, so it is omitted.

<Output mechanism>

The output mechanism 14 can be substantially the same as the output mechanism 4 in the third and fourth embodiments. Here, detailed description is omitted.

<Buffer memory>

The buffer memory can be substantially the same as the buffer memory in the third embodiment. Here, detailed description is omitted.

<Lighting>

The inspection device 40b is further provided with an illumination L5 (18e) that becomes a penetrating light. By using the illumination L5 (18e) which is the transmitted light, for example, it is possible to obtain the effect of easily detecting foreign matter on the transparent inspection object.

<Synchronization Signal Generator>

The synchronization signal generating mechanism 16 can be substantially the same as the synchronization signal generating mechanism 16 in the third and fourth embodiments. Here, detailed description is omitted.

<Lighting Control Mechanism>

The lighting control mechanism 17 can be substantially the same as the lighting control mechanism 17 in the third and fourth embodiments. Here, detailed description is omitted.

<Transportation Organization>

The transport mechanism 19 can be substantially the same as the transport mechanism 19 in the third and fourth embodiments. Here, detailed description is omitted.

In addition, in the present disclosure, it includes appropriate combinations of any of the aforementioned various embodiments, and the effects of each embodiment can be exerted. fruit.

Industrial availability

According to the imaging device and the inspection device of the present invention, at least one of the imaging mechanism and the image data can be calibrated by the imaging conditions, such as the calibration data of the lighting conditions, so that the appropriate imaging conditions (lighting conditions) can be adjusted Correction.

10‧‧‧Camera Device

1‧‧‧Camera mechanism

1a‧‧‧Camera element

1b‧‧‧Camera control mechanism

2‧‧‧Memory Mechanism

2a‧‧‧The first calibration data

2b‧‧‧Second calibration data

2c‧‧‧The third calibration data

2d‧‧‧Fourth calibration data

3‧‧‧Correction mechanism

4‧‧‧Output mechanism

Claims (13)

A camera device, characterized in that the camera device includes a camera mechanism to obtain image data of a subject illuminated by an illumination mechanism, and the aforementioned illumination mechanism can switch between a plurality of different lighting conditions for the subject to be illuminated. The memory mechanism has a plurality of calibration data corresponding to the plurality of lighting conditions in advance, and the calibration data is used to calibrate the image data; the calibration mechanism switches the plurality of calibration data corresponding to the switching of the lighting conditions during shooting, Carry out the correction of the aforementioned image data; and the output mechanism, which outputs the image signal of the corrected image data to the outside of the camera device after being outputted to the outside of the camera device after low-level processing in accordance with the transmission rate when outputting to the outside. The mechanism is to correct the aforementioned image data without being affected by the low-level processing of the aforementioned output mechanism. For example, the imaging device of claim 1, wherein the correction data is shadow correction data for performing shadow correction on the image data, and the correction mechanism is a shadow correction mechanism that uses the shadow correction data to perform shadow correction. For example, the imaging device of claim 1 or 2, wherein the aforementioned correction data is correction data used to perform correction corresponding to the lighting conditions at the time of imaging, and the aforementioned correction mechanism is corresponding to the aforementioned lighting conditions at the time of imaging. In other words, the correction data is switched from the aforementioned plurality of correction data to the correction data corresponding to the aforementioned lighting conditions at the time of shooting to perform correction. Such as the imaging device of claim 3, wherein the aforementioned correction mechanism is synchronized with the switching of the aforementioned lighting conditions during the imaging, and is switched to the correction data corresponding to the aforementioned illumination conditions during the imaging. Such as the imaging device of claim 1, wherein the calibration mechanism is synchronized with the imaging in the imaging mechanism, and the calibration data is switched. An inspection device comprising the aforementioned camera device as in any one of Claims 1 to 5. An inspection device, characterized in that it comprises: a lighting mechanism that can switch a plurality of different lighting conditions to illuminate the inspected object; a camera mechanism to obtain the image data of the inspected object illuminated by the lighting mechanism; and a memory mechanism , Memorizing a plurality of calibration data, the calibration data is used to calibrate at least one of the camera mechanism and the image data corresponding to the plurality of lighting conditions; the calibration mechanism, corresponding to the switching of the lighting conditions during shooting, switch the plurality of calibrations Data, performing correction of at least one of the aforementioned imaging mechanism and the aforementioned image data; and the inspection mechanism, combining a plurality of the aforementioned corrected image data to perform defect inspection of the aforementioned inspection object. The inspection device of claim 7, wherein the aforementioned lighting mechanism has a plurality of lighting devices that perform lighting under different lighting conditions. For example, the inspection device of claim 7 or 8, wherein the correction data is shadow correction data for shadow correction of the image data, and the correction mechanism is a shadow correction mechanism that uses the shadow correction data to perform shadow correction. For example, the inspection device of claim 7 or 8, wherein the calibration data is calibration data related to the storage time of the imaging element in the imaging mechanism, and the calibration mechanism uses the calibration data related to the storage time to adjust the imaging mechanism The storage time mechanism of the image sensor. For example, the inspection device of claim 7 or 8, wherein the calibration data is calibration data related to the gain in the camera mechanism, and the calibration mechanism is a mechanism that uses the calibration data related to the gain to adjust the gain in the camera mechanism. Such as the inspection device of claim 7 or 8, wherein the aforementioned calibration mechanism is synchronized with the switching of the aforementioned lighting conditions during imaging, and is switched to the calibration data corresponding to the aforementioned illumination conditions during imaging. Such as the inspection device of claim 7 or 8, wherein the calibration mechanism is synchronized with the imaging in the imaging mechanism to switch the calibration data.

Images