JP6284276B2 - Component mounter and camera unit - Google Patents

Description

The present invention relates to a component mounting machine and a camera unit including an image processing apparatus that processes an image obtained by capturing a component sucked by a suction nozzle and recognizes the component .

  In various industrial machines used in today's industry, an image processing device that captures an object with a camera during production and inspection processes and recognizes the shape, dimensions, position, etc. of the object with image processing technology There are a lot of things equipped with. Camera performance [number of pixels, resolution, field of view size, transfer speed, number of gradations (monochrome 8bit, monochrome 10bit, color), resolution, etc.] is determined for each camera, so replace the camera according to the required performance. There is a need to. Thus, for example, some component mounting machines are configured such that a camera that captures an image of a component sucked by a suction nozzle can be replaced with a camera having a different performance on the user side.

  In general, images taken with a camera are distorted by a lens, etc., and some of them are equipped with a function to correct image distortion. However, if the camera is replaced, the image distortion also changes, so the image distortion is corrected. It is also necessary to change the image correction parameters used for the processing to be performed.

  Therefore, in the component mounter described in Patent Document 1 (Japanese Patent Laid-Open No. 2011-180084), a camera in which a lens distortion correction jig in which dot marks are displayed in a matrix at a predetermined pitch is attached to the component mounter in advance. The difference (distortion amount) between the recognized position and the theoretical position of each dot mark of the lens distortion correction jig obtained by the image processing is calculated as an image correction parameter, and this image correction parameter is calculated as a component mounter. The image processing apparatus of the component mounter reads the image signal transferred from the camera from the storage medium of the image processing apparatus during actual production. Correction is performed using image correction parameters.

JP 2011-180084 A

  However, in the image correction method of Patent Document 1 described above, every time the camera attached to the component mounter is replaced, before starting production, the lens distortion correction jig is imaged with the camera attached to the component mounter, and the image correction parameter is set. Thus, there is a drawback that preparation work for storing the image correction parameters in the storage medium of the image processing apparatus of the component mounter has to be performed, which requires time and labor when replacing the camera.

Therefore, the problem to be solved by the present invention is to provide a component mounter and a camera unit that can simplify the work at the time of camera replacement.

In order to solve the above-described problems, the present invention provides a camera unit that is replaceably mounted on a component mounter including an image processing device that recognizes the component by processing an image obtained by capturing the component adsorbed by the adsorption nozzle. The camera unit includes an image pickup device that picks up an image of the component that is an image pickup object, a lens that is fixed to the image pickup device in a predetermined positional relationship, and an image distortion that is determined by the positional relationship between the lens and the image pickup device. A non-volatile storage unit storing image correction parameters used for correcting the image, and reading the image correction parameter from the storage unit and correcting an image signal captured by the image sensor using the image correction parameter that the image correcting means for transferring the image signal corrected to the image processing device is provided as a first aspect, further, to the camera unit, before A second feature is that an illumination light source that illuminates the component that is the imaging target is provided, and the image correction parameter includes a parameter for correcting an influence on the captured image by illumination of the illumination light source. To do.

  Since distortion of an image captured by the image sensor of the camera is determined by the positional relationship between the image sensor and the lens, as long as the image sensor and the lens are fixed to the camera unit in a predetermined positional relationship as in the present invention. The condition (positional relationship between the image sensor and the lens) that causes image distortion does not change before and after the camera unit is attached to the component mounter. Focusing on this point, the present invention provides a non-volatile storage means in which an image sensor and a lens are fixed to a camera unit in a predetermined positional relationship, and image correction parameters for correcting image distortion are stored. When the camera unit attached to the component mounter is replaced, the image processing device of the component mounter performs image correction from the nonvolatile storage means of the replaced camera unit. Since the parameters can be acquired, it is not necessary to perform the preparatory work of capturing the lens distortion correction jig before starting production and obtaining the image correction parameters and storing them in the storage medium of the image processing apparatus of the component mounting machine as in the past. The work when replacing the camera unit can be simplified. As a result, it is possible to easily configure an imaging system having different resolutions and optical characteristics only by exchanging the camera unit.

In addition, according to the present invention, the camera unit is provided with image correction means for correcting the image signal using the image correction parameter in addition to the nonvolatile storage means in which the image correction parameter is stored. Even when no image correction means is provided, there is an advantage that image correction processing can be performed on the camera unit side.

Furthermore, the present invention is the camera unit, Rutotomoni provided an illumination light source for illuminating the component is imaged object, the image correction parameter to correct the influence on the image captured by the illumination of the illumination light source (uneven shading or contrast) To include parameters . If the lighting conditions change, shading of the captured image and unevenness of the contrast also change, but if the imaging element, lens, and illumination light source are fixed to the camera unit in a predetermined positional relationship, the illumination conditions can be fixed. Conditions that cause an effect on the captured image (shading and uneven contrast) can also be fixed. Therefore, when an illumination light source is provided in the camera unit, if the image correction parameter includes a parameter for correcting the influence of the illumination light source on the captured image, the image distortion is corrected and the illumination light source is illuminated. The influence on the captured image can also be corrected.

  Furthermore, when using an image sensor including a defective pixel, a parameter for correcting a pixel defect may be included in the image correction parameter. In this way, when using an image sensor including defective pixels, it is possible to correct pixel defects as well as image distortion correction.

  In this case, the image correction means may be configured using a programmable logic device. As the programmable logic device, for example, a field programmable gate array (FPGA), a complex programmable logic device (CPLD), or the like may be used. Thereby, the function as the image correction means can be easily installed by software.

FIG. 1 is a block diagram showing a system configuration of a first embodiment as a reference example related to the present invention. FIG. 2 is a longitudinal sectional view showing the configuration of the camera unit. FIG. 3 is a block diagram showing a system configuration of Embodiment 2 of the present invention.

Hereinafter, the embodiments of the present invention will be described with reference to two Examples 1 and 2.

Example 1 as a reference example related to the present invention will be described with reference to FIGS.
First, the configuration of the camera unit 11 that is replaceably attached to the component mounter will be described with reference to FIG.

  In the camera unit 11, a camera 12 incorporating an image sensor, a lens 13, and an illumination light source 14 are fixed in a predetermined positional relationship. Specifically, a lens 13 is fixed to the light receiving surface side (upper surface side in FIG. 2) of the camera 12, and a dome-shaped (bowl-shaped) illumination light source 14 is directed upward on the lens 13 via a box-shaped member 15. The center of the camera 12 (optical axis), the center of the lens 13 and the center of the illumination light source 14 are arranged to coincide with each other. A plurality of light emitting elements 16 such as LEDs are provided on the dome-shaped inner surface of the illumination light source 14. Although not shown, a part (imaging target) sucked by a suction nozzle of a component mounting machine is picked up by the camera 12 from below. At that time, the illumination light source 14 illuminates the component from below. The upper surface of the illumination light source 14 is covered with a transparent cover 17 through which illumination light is transmitted.

  The camera unit 11 is provided with a non-volatile memory 20 (see FIG. 1) such as a flash memory, ROM, PROM, EPROM, or EEPROM, which is a non-volatile storage means. The nonvolatile memory 20 stores image correction parameters used for correcting image distortion determined by the positional relationship between the lens 13 and the image sensor of the camera 12. In the present embodiment, the non-volatile memory 20 also stores an image correction parameter for correcting the influence (shading or contrast unevenness) on the captured image by illumination of the illumination light source 14 and an image correction parameter for correcting pixel defects. Has been.

  These image correction parameters are measured by the manufacturer of the camera unit 11 using the camera unit 11 and stored in the nonvolatile memory 20. For example, an image correction parameter for correcting image distortion is obtained by imaging a lens distortion correction jig on which a dot matrix or a checker pattern having a predetermined pitch is displayed in advance with the camera 12 and for each predetermined pitch (every dot interval or every lattice interval). The distortion amount is measured, and the distortion amount is stored as an image correction parameter for image distortion correction. Further, image correction parameters for correcting the influence (shading and unevenness of contrast) on the captured image due to illumination of the illumination light source 14 are set in advance while illuminating a correction reference plane colored in, for example, white or black with the illumination light source 14 in advance. The image is taken by the camera 12 and measured for each pixel. Image correction parameters for correcting pixel defects are stored in advance in the nonvolatile memory 20 as pixel correction image correction parameters for the positions of defective pixels detected in advance. A pixel defect is corrected by interpolation correction or the like using the luminance of the pixel.

Next, the configuration of the image processing apparatus 21 of the component mounter will be described with reference to FIG.
The image processing apparatus 21 is configured using an image processing board on which a CPU 22, a chip set 23, a memory 24 such as a RAM, an FPGA 25 that is a programmable logic device, and the like are mounted. The FPGA 25 is written with a program for correcting the image signal transferred from the camera unit 11 using the image correction parameter read from the nonvolatile memory 20 of the camera unit 11. As a result, the FPGA 25 serves as image correction means in the claims.

The CPU 22 of the image processing device 21 writes the image correction parameters read from the nonvolatile memory 20 of the camera unit 11 to the FPGA 25 when the power is turned on, and the image transferred from the camera unit 11 attached to the component mounter to the FPGA 25. Signal to the FPG
In A25, correction is performed using the image correction parameter, and the corrected image signal is transferred to the memory 24 and stored therein. The CPU 22 of the image processing device 21 executes an image processing application, reads the corrected image signal from the memory 24, performs image processing, and recognizes a component that is an imaging target.

  According to the first embodiment described above, the camera 12, the lens 13, and the illumination light source 14 are fixed to the camera unit 11 in a predetermined positional relationship, and image distortion correction, shading correction, contrast correction, and pixel defect correction are performed. The camera unit 11 is provided with a non-volatile memory 20 in which image correction parameters used for the camera are stored. The image processing apparatus 21 of the component mounter reads the image correction parameters from the non-volatile memory 20 of the camera unit 11 and transfers them from the camera unit 11. An FPGA 25 for correcting the received image signal using the image correction parameter is provided.

  Since distortion of an image captured by the camera 12 (imaging device) is determined by the positional relationship between the camera 12 and the lens 13, the camera 12 and the lens 13 are placed at predetermined positions in the camera unit 11, as in the first embodiment. If the relationship is fixed, the condition for causing image distortion (positional relationship between the camera 12 and the lens 13) does not change before and after the camera unit 11 is attached to the component mounter. Focusing on this point, in the first embodiment, the camera 12 and the lens 13 are fixed to the camera unit 11 in a predetermined positional relationship, and non-volatile in which image correction parameters for correcting image distortion are stored. The memory 20 is provided in the camera unit 11, so that when the camera unit 11 attached to the component mounter is replaced, the image processing device 21 of the component mounter can Since the image correction parameters can be acquired from the non-volatile memory 20, the lens distortion correction jig is imaged before the start of production as in the prior art, and the image correction parameters are obtained and stored in the storage medium of the image processing device 21 of the component mounting machine. Thus, it is possible to simplify the work when replacing the camera unit 11. Thereby, it is possible to easily configure an imaging system having different resolutions and optical characteristics only by exchanging the camera unit 11.

  If the illumination condition changes, the shading of the captured image and the unevenness of the contrast also change. However, as in the first embodiment, the illumination light source 14 is placed in a predetermined positional relationship with the camera 12 and the lens 13 in the camera unit 11. If it is fixed, the illumination condition can be fixed, so that the condition (shading and contrast unevenness) on the captured image due to the illumination of the illumination light source 14 can also be fixed. Therefore, when the illumination light source 14 is provided in the camera unit 11 as in the first embodiment, the image correction parameter stored in the nonvolatile memory 20 of the camera unit 11 has an influence on the captured image due to the illumination of the illumination light source 14. By including parameters for correction, it is possible to correct not only the image distortion but also the influence on the captured image due to the illumination of the illumination light source 14.

  In addition, in the first embodiment, the image correction parameter stored in the nonvolatile memory 20 of the camera unit 11 includes the parameter for correcting the pixel defect. Therefore, the pixel defect is corrected together with the image distortion correction. Can do.

  Furthermore, in the first embodiment, the FPGA 25 that is faster than the CPU 22 is used as the image correction unit that corrects the image signal using the image correction parameter, so that the image correction process can be performed at a high speed and the number of pixels can be increased. Can be easily accommodated.

  Further, since the camera unit 11 is not provided with an image correction function, the camera unit 11 does not need to be provided with an expensive FPGA and can meet the demand for cost reduction of the camera unit 11.

  In addition, since the image processing apparatus 21 of the component mounter is provided with the FPGA 25 that functions as an image correction unit, the image correction process can be performed even if it is replaced with various types of camera units having no image correction function.

  Next, Embodiment 2 of the present invention will be described with reference to FIG. However, substantially the same parts as those in the first embodiment are denoted by the same reference numerals, description thereof is omitted or simplified, and different parts are mainly described.

  In the first embodiment, the image processing apparatus 21 of the component mounter is provided with the FPGA 25 that functions as an image correction unit. However, in the second embodiment of the present invention illustrated in FIG. 3, the camera unit 11 functions as the image correction unit. FPGA 25 is provided. Therefore, the image processing apparatus 21 of the component mounter is not provided with the FPGA 25 that functions as an image correction unit. The camera unit 11 is provided with a non-volatile memory 20 in which image correction parameters are stored, as in the first embodiment.

  In this configuration, the FPGA 25 of the camera unit 11 corrects the image signal transferred from the camera 12 using the image correction parameter read from the non-volatile memory 20, and the corrected image signal is subjected to image processing of the component mounter. The data is transferred to the device 21 and stored in the memory 24. The image processing apparatus 21 of the component mounter reads an image signal after correction from the memory 24 and executes image processing by executing an image processing application, and recognizes a component that is an imaging target.

In the second embodiment described above, the same effect as that of the first embodiment can be obtained.
In the second embodiment, since the FPGA 25 that functions as the image correction unit is provided in the camera unit 11, even when the FPGA 25 that functions as the image correction unit is not provided in the image processing device 21 of the component mounter, the image is displayed. Correction processing can be performed.

  In the first and second embodiments, the image correction parameters stored in the nonvolatile memory 20 of the camera unit 11 include image correction parameters used for image distortion correction, shading correction, contrast correction, and pixel defect correction. The present invention only needs to include at least image correction parameters used for image distortion correction, and may be configured not to include some or all image correction parameters of shading correction, contrast correction, and pixel defect correction.

  Further, the object to be imaged by the camera unit 11 attached to the component mounter in a replaceable manner is not limited to the component, and the mark on the board, the component mounting state, and the like may be imaged.

In addition, the present invention can be variously modified without departing from the Abstract.

  DESCRIPTION OF SYMBOLS 11 ... Camera unit, 12 ... Camera (imaging element), 13 ... Lens, 14 ... Illumination light source, 20 ... Non-volatile memory (non-volatile memory | storage means), 21 ... Image processing apparatus, 22 ... CPU, 23 ... Chip set, 24 ... memory, 25 ... FPGA (programmable logic device, image correction means)

Claims (6)

A component mounting machine comprising a camera unit that is attached in a replaceable manner and that captures an image of a component adsorbed by an adsorption nozzle, and an image processing device that processes an image signal transferred from the camera unit and recognizes the component In
The camera unit has an image pickup device that picks up an image of the component that is an image pickup object, a lens that is fixed to the image pickup device in a predetermined positional relationship, and an image distortion that is determined by the positional relationship between the lens and the image pickup device. Nonvolatile storage means in which image correction parameters used for correction processing are stored, and the image correction parameters are read from the storage means and the image signal captured by the image sensor is corrected and corrected using the image correction parameters. Image correction means for transferring a subsequent image signal to the image processing apparatus ,
Furthermore, the camera unit is provided with an illumination light source that illuminates the component that is the imaging object,
The component mounter according to claim 1, wherein the image correction parameter includes a parameter for correcting an influence on a captured image by illumination of the illumination light source . The component mounting machine according to claim 1, wherein the image correction parameter includes a parameter for correcting a pixel defect. Wherein the image correcting means, the component mounting apparatus according to claim 1 or 2, characterized in that it is constructed using a programmable logic device. In a camera unit that is replaceably attached to a component mounter equipped with an image processing device that recognizes the component by processing an image obtained by imaging the component adsorbed by the adsorption nozzle,
An image used to correct an image distortion determined by the positional relationship between the imaging element that images the component that is the imaging target, a lens that is fixed to the imaging element in a predetermined positional relationship, and the lens and the imaging element Nonvolatile storage means in which correction parameters are stored, and the image correction parameters read from the storage means and image signals captured by the image sensor are corrected using the image correction parameters to obtain corrected image signals A camera unit provided with image correction means for transferring to an image processing apparatus ,
An illumination light source for illuminating the component that is the imaging object is provided,
The camera unit according to claim 1, wherein the image correction parameter includes a parameter for correcting an influence on a captured image by illumination of the illumination light source . The camera unit according to claim 4 , wherein the image correction parameter includes a parameter for correcting a pixel defect. The camera unit according to claim 4 , wherein the image correction unit is configured using a programmable logic device.

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