JPWO2020136885A1 - Three-dimensional measuring device and work work device - Google Patents

Abstract

A three-dimensional measuring device for measuring the height of the component E, which is a pattern light 65 in which the relative brightness (hue) between a plurality of wavelengths is continuously changed in a predetermined direction, and is a pattern light 65 of each wavelength. A pattern light 65 whose calculated values of a predetermined calculation formula using the brightness of light as a variable do not overlap within one cycle of the change in brightness is directed in a predetermined direction toward a reference plane 62 which is a reference of the height of the component E. The first light source unit 39A that projects obliquely from the light source, the first light receiving unit 39B that receives the pattern light 65 reflected by the component E for each wavelength, and the light that the first light receiving unit 39B receives for each wavelength. A three-dimensional measuring device including a control unit 33 that obtains the height of the component E based on the amount of light received.

Description

The techniques disclosed herein relate to three-dimensional measuring devices and workpiece work devices.

Conventionally, a phase shift method is known as a method of measuring the height of a measurement target using an imaging unit such as a digital camera (see, for example, Patent Document 1). In the phase shift method, light whose black and white changes due to a sine wave is imaged multiple times in the same region of the measurement target by shifting the phase by 1/3 or 1/4, and the height of the measurement target is measured from the phase difference. The method.

Further, conventionally, a light cutting method is also known as a method for measuring the height of a measurement target. The optical cutting method projects spot light or line light onto a measurement target, and measures the height from the position of a light receiving element that receives the light reflected by the measurement target by the principle of triangulation.

Japanese Unexamined Patent Publication No. 2015-1381

However, in the phase shift method, it takes time to measure because the same region to be measured must be imaged a plurality of times with the phase shifted. In addition, since the optical cutting method can obtain only the height information on the line, it is necessary to move and image the line by the number of pixels in the direction orthogonal to the line in order to obtain the height information of the entire field of view. Will increase significantly.
This specification discloses a technique capable of measuring the height of a measurement target in a shorter time than the phase shift method or the optical cutting method.

The three-dimensional measuring device disclosed in the present specification is a three-dimensional measuring device that measures the height of a measurement target, and is a pattern in which the relative brightness between a plurality of wavelengths continuously changes in a predetermined direction. A pattern light that is light and whose calculated values of a predetermined calculation formula with the brightness of the light of each wavelength as a variable does not overlap within one cycle of the change in brightness is used as a reference for the height of the measurement target. A first light source unit that projects obliquely from the predetermined direction toward a reference plane, a first light receiving unit that receives the pattern light reflected by the measurement target for each wavelength, and the first light receiving unit. The light receiving unit includes a control unit that obtains the height of the measurement target based on the amount of light received by the light receiving unit for each wavelength.

Even if light of multiple wavelengths is reflected on an achromatic surface (black, white or gray with an intermediate brightness, etc.), the ratio of the brightness of the light of each wavelength (relative brightness between multiple wavelengths) changes. do not. In other words, when light of multiple wavelengths is reflected on an achromatic surface, the ratio of the brightness of the reflected light of each wavelength is the brightness of the achromatic surface (black, white or gray with an intermediate brightness). Etc.) and the brightness of the light itself.
Therefore, when the predetermined calculation formula has the same calculation value if the ratio of the brightness of light of each wavelength is the same, the relative brightness between the plurality of wavelengths is continuous in the predetermined direction. The pattern light that is changing and whose calculated values of the predetermined formula do not overlap within one cycle of the change in the brightness of the light of each wavelength is projected onto the achromatic surface, and the pattern light is projected. When the calculated value of the predetermined calculation formula is obtained from the received amount of light of each wavelength reflected at each position in the projected region, the calculated calculation value is the brightness of the measurement target or the brightness of the pattern light itself. Regardless, it becomes a unique value (unique value) for each position.
Therefore, for example, a pattern light is projected on a reference plane that serves as a reference for height in advance, and the amount of light received for each wavelength of the pattern light reflected at each position or a calculated value obtained from the amount of light received by a predetermined calculation formula. If the above is stored, the height of each position can be determined from the amount of light received by the pattern light reflected by the measurement target and the amount of light received or the calculated value stored in advance.
That is, when the pattern light is used, the calculated value becomes a unique value for each position regardless of the brightness of the measurement target or the brightness of the pattern light itself, so it is not necessary to image the same region multiple times as in the phase shift method. Can also measure the height. In addition, the height can be measured without moving and imaging the line by the number of pixels in the direction orthogonal to the line as in the optical cutting method.
Therefore, according to the above-mentioned three-dimensional measuring device, the height of the measurement target can be measured in a shorter time than the phase shift method or the optical cutting method.
The surface to be measured is not limited to achromatic color. When the surface to be measured is chromatic, light outside the visible region (in other words, light in the invisible region) may be projected. If the light in the invisible region is projected, the same effect can be obtained because the ratio of the brightness of the light of a plurality of wavelengths does not change even if it is reflected by the chromatic surface.

The control unit may obtain the calculated value of the predetermined calculation formula from the received amount of light received by the first light receiving unit for each wavelength, and obtain the height of the measurement target based on the calculated value. good.

According to the above-mentioned three-dimensional measuring device, for example, pattern light is projected in advance on a reference plane that serves as a reference for height, and the pattern light reflected at each position is calculated from the amount of received light received for each wavelength by a predetermined calculation formula. The calculated value is stored, and the measurement target is based on the calculated value calculated by the predetermined calculation formula from the received amount of light received by the first light receiving unit for each wavelength and the calculated value stored in advance. The height of can be calculated.

The pattern light may be projected on a predetermined range of the reference plane.

According to the above-mentioned three-dimensional measuring device, the height of the measurement target can be measured by arranging the measurement target within the above-mentioned predetermined range.

The first light source unit projects the linear pattern light, the first light receiving unit is a plurality of line sensors extending in parallel in the main scanning direction, and the three-dimensional measuring device is the first. A moving unit that moves the light source unit 1 and the line sensor relative to the measurement target in the sub-scanning direction orthogonal to the main scanning direction may be provided.

According to the above-mentioned three-dimensional measuring device, the imaging range can be changed according to the size of the measurement target by changing the amount of relative movement.

The first light source unit projects the planar pattern light, and the first light receiving unit may be an area sensor.

According to the above-mentioned three-dimensional measuring device, since the entire measurement target can be imaged at one time, the height can be measured in a shorter time than when a line sensor is used.

The plurality of wavelengths may be wavelengths outside the visible region.

Since wavelengths outside the visible region (hereinafter referred to as wavelengths in the invisible region) are not affected (or difficult to be affected) by the color of the measurement target, the height can be measured even if the color of the measurement target is a chromatic color.

In the pattern light, the relative brightness between the plurality of wavelengths may change continuously and periodically, and the fluctuation range of the brightness may differ for each period.

If the height of the measurement target exceeds the width of one cycle of the pattern light, if the pattern light is phase-connected and projected for multiple cycles, the calculated values will overlap between the cycles, and the height will be erroneously measured. there is a possibility.
By making the fluctuation range of brightness different for each cycle, even if the same calculated value is obtained in each cycle, it is possible to specify which cycle the calculated value is from the difference in the fluctuation range of brightness. Therefore, even if the height of the measurement target exceeds the width of one cycle of the pattern light, the height of the measurement target can be measured by one imaging.

The control unit represents the calculated value obtained from the received amount of light received by the first light receiving unit for each wavelength and the calculated value obtained from the brightness of the light of each of the wavelengths of the pattern light. The height of the measurement target may be obtained based on the reference plane map.

According to the above-mentioned three-dimensional measuring device, the height of the measurement target can be obtained by using the reference plane map.

The control unit may create the reference plane map by obtaining the calculated value from the theoretical brightness of the light of each of the wavelengths of the pattern light by the predetermined calculation formula.

According to the above-mentioned three-dimensional measuring device, since the reference plane map can be created without using the reference plate, the reference plane map can be created with a simple configuration.

It has a reference plate arranged so as to coincide with the reference plane, and the control unit projects the pattern light onto the reference plate by the first light source unit, and is reflected by the reference plate to be reflected by the reference plate. The reference plane map may be created by obtaining the calculated value by the predetermined calculation formula from the received amount of light for each wavelength of the pattern light received by the light receiving unit of 1.

According to the above-mentioned three-dimensional measuring device, since the reference plate is provided, the brightness of the first light source unit and the light reception sensitivity of the first light receiving unit can be adjusted by periodically creating a reference plane map from the reference plate. It is possible to suppress a decrease in measurement accuracy even if it changes over time.

It has a reference plate arranged so as to coincide with the reference plane, and the control unit projects the pattern light onto the reference plate by the first light source unit, and is reflected by the reference plate to be reflected by the reference plate. A partial map is created by obtaining the calculated value from the received amount of light for each wavelength of the pattern light received by the light receiving unit 1 by the predetermined calculation formula, and the partial map is used to obtain the calculated value. The reference plane map may be created by interpolating other parts of the reference plane map.

According to the above-mentioned three-dimensional measuring device, the reference plate can be made smaller than the case of using a large reference plate capable of creating the entire reference plane map at one time.

The pattern light is projected by the first light source unit onto a reference plate provided with a storage unit and arranged so as to coincide with the reference plane, reflected by the reference plate, and received by the first light receiving unit. In the reference plane map representing the calculated value obtained by the predetermined calculation formula from the received amount of light for each wavelength of the pattern light, a plurality of the above, which are arranged in the direction in which the brightness of the light of each wavelength changes. When the calculated value is defined as a row and a plurality of the calculated values arranged in a direction orthogonal to the direction are defined as a column, the storage unit stores the average value obtained by averaging the calculated values for each column. The control unit receives the amount of light received for each wavelength of the pattern light reflected by the measurement target and received by the first light receiving unit, and the average value for each column stored in the storage unit. The height of the measurement target may be obtained based on the above.

Since the reference plane map has a large amount of data, storing the entire reference plane map in the storage unit requires a large-capacity storage unit, which increases the manufacturing cost of the three-dimensional measuring device.
According to the above-mentioned three-dimensional measuring device, since the average value obtained by averaging the calculated values for each column is stored in the storage unit, the amount of data stored in the storage unit is the amount of data for one row of the reference plane map. Therefore, the storage area of the storage unit can be saved as compared with the case where the entire reference plane map is stored.

The pattern light is projected by the first light source unit onto a reference plate provided with a storage unit and arranged so as to coincide with the reference plane, reflected by the reference plate, and received by the first light receiving unit. In the reference plane map representing the calculated value obtained by the predetermined calculation formula from the received amount of light for each of the wavelengths of the pattern light, the plurality of said light sources arranged in the direction in which the brightness of the light of each said wavelength changes. When the calculated value is defined as a row and a plurality of the calculated values arranged in a direction orthogonal to the direction are defined as a column, the storage unit contains the predetermined number of rows at one end in the column direction for each column. The average value obtained by averaging the calculated values is stored, and the average value obtained by averaging the calculated values is stored for each column for a predetermined number of rows at the other end in the column direction. Each row of the reference plane map is stored in the storage unit from the average value for each column of the predetermined number of rows at one end and the average value for each column of the predetermined number of rows at the other end. The reference plane map may be restored by interpolating.

When creating a reference plane map from an image captured by projecting pattern light on a reference plate, the reference plane map is created by tilting because the relative angle between the first light source unit and the first light receiving unit is tilted. May be done. In that case, the measurement target is also tilted and the image is taken, but since the reference plane map is also tilted, there is no problem in measuring the height.
However, if the average value obtained by averaging the calculated values for each column is stored in the storage unit and the average value for each stored column is used as the reference plane map, a non-tilted reference plane map is used.
According to the above-mentioned three-dimensional measuring device, the storage unit stores the average value for each column of a predetermined number of rows at one end in the column direction and the average value for each column of a predetermined number of rows at the other end. Therefore, the storage area of the storage unit can be saved as compared with the case where the entire reference plane map is stored. Then, according to the above-mentioned three-dimensional measuring device, since each line of the reference plane map is interpolated from the average value thereof, the reference plane map in the tilted state can be restored. Therefore, the height can be accurately measured even if the relative angle between the first light source unit and the first light receiving unit is tilted.

The control unit creates a multi-valued image representing the brightness of the measurement target from the amount of light received for each wavelength of the pattern light reflected by the measurement target and received by the first light receiving unit. You may.

There is a region where there is no step in the measurement target, and a figure such as a character or a polarity mark may be written in the region with a brightness different from the brightness of the region. Since the 3D measuring device measures the height of parts from the relative brightness of light of multiple wavelengths, it is not affected by the brightness of the measurement target, but from the amount of light received in each wavelength in the process, It is possible to create a multi-valued image showing the brightness of the measurement target. That is, by imaging the entire component once, it is possible to measure the height of the component and recognize the figure displayed on the measurement target.

The first light source unit includes a changing unit that relatively changes the direction in which the pattern light is projected onto the measurement target, and the control unit relatively changes the direction by the changing unit. The pattern light may be projected onto the first light source unit in order from at least two directions.

If the pattern light is projected onto the measurement target in only one direction, a shaded portion where the pattern light is not projected may occur depending on the shape of the measurement target, and the height of the measurement target may not be measured over the entire surface.
According to the above three-dimensional measuring device, the direction in which the pattern light is projected onto the measurement target is relatively changed to project the pattern light in order from at least two directions. Therefore, when the pattern light is projected in only one direction. Compared to the above, there is a high possibility that the height of the measurement target can be measured over the entire surface.

A second light source unit that obliquely projects the pattern light having a wavelength different from that of the pattern light projected by the first light source unit from a direction different from that of the first light source unit toward the reference plane. The control unit includes the first light source unit and the second light source unit that receives the pattern light projected by the second light source unit and reflected by the measurement target for each wavelength. The pattern light may be projected onto the second light source unit at the same time.

If the pattern light is projected in only one direction, a shaded portion where the pattern light is not projected may occur depending on the shape of the measurement target, and the height of the measurement target may not be measured over the entire surface.
According to the above three-dimensional measuring device, since the pattern light is projected onto the measurement target from a plurality of directions, the height of the measurement target is measured over the entire surface as compared with the case where the pattern light is projected in only one direction. There is a high possibility that it can be done.
Further, according to the three-dimensional measuring device, the wavelength of the pattern light projected by the first light source unit and the wavelength of the pattern light projected by the second light source unit are different, so these are simultaneously projected onto the measurement target. Even so, light of each wavelength can be received individually. Therefore, the pattern light can be projected from the first light source unit and the second light source unit at the same time to image the measurement target. Therefore, the time required for imaging can be shortened, and the height of the measurement target can be measured in a short time.

The work work apparatus disclosed in the present specification is described in any one of claims 1 to 12, wherein the work unit that performs a predetermined work on the work and the height of the object involved in the work are measured. It is equipped with a three-dimensional measuring device.

According to the work work apparatus described above, the height of the measurement target can be measured in a shorter time than the phase shift method or the optical cutting method.

Schematic diagram of the component mounting line according to the first embodiment Schematic diagram of surface mounter viewed from above Schematic diagram of the head unit seen from the front side Schematic diagram showing a component imaging camera viewed from the X direction Schematic diagram showing a component imaging camera viewed from the Y direction Block diagram showing the electrical configuration of the surface mounter Schematic diagram showing the color wheel (A) is a schematic diagram of a trapezoidal wave, and (B) is a schematic diagram of a color image. (A) is a schematic diagram of a sine wave, and (B) is a schematic diagram of a color image. Schematic diagram for explaining height measurement of parts Schematic diagram for explaining the procedure of height measurement Schematic diagram for explaining height calculation Schematic diagram showing the underside of the part (A) is a schematic diagram for explaining the method 1 for reducing the amount of data according to the second embodiment, and (B) is a schematic diagram for explaining the method 2 for reducing the amount of data according to the second embodiment. Schematic diagram for explaining another method 2 for creating a reference plane hue map according to the third embodiment. (A) is a schematic diagram of a trapezoidal wave according to the fourth embodiment, and (B) is a schematic diagram of a color image. (A) is a schematic diagram of a sine wave, and (B) is a schematic diagram of a color image. (A) is a schematic diagram of an independent wave, and (B) is a schematic diagram of a color image. Schematic diagram for explaining the procedure of height measurement (A) is a schematic diagram of a color image according to the fifth embodiment, and (B) is a schematic diagram of another color image. Schematic diagram of the component imaging camera according to the sixth embodiment (A) is a graph of hue values according to other embodiments, and (B) is a graph in which the phase of the graph shown in (A) is corrected.

<Embodiment 1>
The first embodiment will be described with reference to FIGS. 1 to 13. In the following description, the reference numerals of the drawings may be omitted for the same constituent members except for some parts.

(1) Component mounting line The component mounting line 10 will be described with reference to FIG. The component mounting line 10 is a line for mounting component E (see FIG. 2, an example of a measurement target and an object related to work) on a substrate W (see FIG. 2, an example of a work). The component mounting line 10 includes a loader 11, a screen printing machine 12, a printing inspection machine 13, a dispenser 14, a plurality of surface mounting machines 15 (an example of a work work device), a post-mounting visual inspection machine 16, a reflow device 17, and a post-curing appearance. An inspection device 18 and an unloader 19 are provided, and these are connected in series via a plurality of conveyors 20.

The loader 11 is a device that supplies the substrate W housed in the rack to the screen printing machine 12.
The screen printing machine 12 is a device that forms a circuit by screen-printing a solder paste on the surface of the substrate W.
The printing inspection machine 13 is a device that inspects the solder screen-printed by the screen printing machine 12.

The dispenser 14 is a device for applying an adhesive to the substrate W.
The surface mounter 15 is a device that performs a mounting operation (an example of a predetermined operation) for mounting a component E on a substrate W. The configuration of the surface mounter 15 will be described later.
The post-mounting visual inspection machine 16 is a device that inspects the appearance of the substrate W after the component E is mounted by the surface mounting machine 15.

The reflow device 17 is a device that melts the solder paste at a high temperature and electrically connects the component E and the electrode (so-called land) on the substrate W.
The post-curing visual inspection device 18 is a device that inspects the appearance of the substrate W after the solder paste melted by the reflow device 17 is cured.
The unloader 19 is a device for storing the substrate W sent out from the visual inspection device 18 after curing in a rack.

(1-1) Configuration of Surface Mounter The configuration of the surface mounter 15 will be described with reference to FIG. In the following description, the X direction shown in FIG. 2 is referred to as a left-right direction, the Y direction is referred to as a front-back direction, and the Z direction shown in FIG. 3 is referred to as a vertical direction. Further, in the following description, the right side shown in FIG. 2 is referred to as an upstream side, and the left side is referred to as a downstream side.

The surface mounter 15 is supplied by a base 29, a substrate transfer device 30 that conveys a substrate W, a backup device (not shown), four tape component supply devices 31 that supply components E to be mounted on the substrate W, and a tape component supply device 31. It includes a component mounting device 32 for mounting the component E on the substrate W, a control unit 33 (see FIG. 6), and an operation unit 34 (see FIG. 6). The board transfer device 30, the backup device, the tape component supply device 31, and the component mounting device 32 are examples of working units.

The board transfer device 30 carries the board W from the upstream side in the X direction to the work position A, and carries out the board W on which the component E is mounted at the work position A to the downstream side. The substrate transfer device 30 includes a pair of conveyor belts 30A and 30B that circulate and drive in the X direction, a conveyor drive motor 60 that drives the conveyor belts 30A and 30B (see FIG. 6), and the like. The rear conveyor belt 30A can be moved in the front-rear direction, and the distance between the two conveyor belts 30A and 30B can be adjusted according to the width of the substrate W.

A backup device (not shown) is located below the working position A. The backup device includes a plurality of backup pins set at positions according to the type of the substrate W, and when the substrate W is conveyed to the working position A, the backup pins are raised to support the substrate W from below.

The tape component supply devices 31 are arranged at two locations in the X direction on both sides of the component mounting device 32 in the Y direction, for a total of four locations. A plurality of feeders 35 are attached to these tape component supply devices 31 side by side in the X direction. Each feeder 35 is provided with a reel on which a component tape containing a plurality of components E is wound, an electric tape delivery device for pulling out the component tape from the reel, and the like, and is provided at the end on the working position A side. Parts E are supplied one by one from the specified component supply positions.

Although the tape component supply device 31 will be described here as an example of the component supply device, the component supply device may be a so-called tray feeder that supplies a tray on which the component E is placed, or may supply a semiconductor wafer. It may be something to do.

The component mounting device 32 includes a head unit 36, a head transport unit 37 (an example of a moving unit), a substrate imaging camera 38, and two component imaging cameras 39 (an example of an imaging unit). The component imaging camera 39 and the control unit 33 (see FIG. 6) constitute the three-dimensional measuring device according to the first embodiment.

The head unit 36 includes a plurality of (five here) mounting heads 40, and the mounting heads 40 attract and release the component E. The head unit 36 according to this embodiment is a so-called in-line type, and a plurality of mounting heads 40 are provided side by side in the X-axis direction. The configuration of the head unit 36 will be described later.

The head transport unit 37 transports the head unit 36 in the X direction and the Y direction within a predetermined movable range. The head transport unit 37 supports the beam 41 that supports the head unit 36 so as to be reciprocally movable in the X direction, the pair of Y-axis guide rails 42 that support the beam 41 so that the beam 41 can be reciprocated in the Y direction, and the head unit 36. It includes an X-axis servomotor 56 that reciprocates in the direction, a Y-axis servomotor 57 that reciprocates the beam 41 in the Y direction, and the like.

The substrate imaging camera 38 is provided in the head unit 36. The substrate imaging camera 38 is for recognizing the position and inclination of the substrate W by imaging a fiducial mark (not shown) attached to the substrate W from above, and is arranged with the imaging surface facing downward. Has been done.

The two component imaging cameras 39 are provided between the two tape component supply devices 31 arranged in the X-axis direction, respectively. The component imaging camera 39 images the component E attracted to the mounting head 40 from below to obtain the shape of the component E, the position of the component E with respect to the mounting head 40, the rotation angle of the component E around the central axis of the mounting head 40, and the like. It is for recognition and is arranged with the imaging surface facing up. Further, in the present embodiment, the component imaging camera 39 is also used for measuring the height of the component E. The configuration of the component imaging camera 39 will be described later.

The configuration of the head unit 36 will be described with reference to FIG. The head unit 36 includes five mounting heads 40, a Z-axis servomotor 58 that raises and lowers each mounting head 40 individually (see FIG. 6), and an R-axis servomotor 59 that simultaneously rotates each mounting head 40 around an axis (FIG. 6). Refer to 6 and an example of the changed part).

Each mounting head 40 has a nozzle shaft 40A and a suction nozzle 40B detachably attached to the lower end of the nozzle shaft 40A. Negative pressure and positive pressure are supplied to the suction nozzle 40B from an air supply device (not shown) via the nozzle shaft 40A. The suction nozzle 40B sucks the component E by supplying a negative pressure, and releases the component E by supplying a positive pressure.

Although the in-line type head unit 36 has been described here as an example, the head unit 36 may be, for example, a so-called rotary head in which a plurality of mounting heads 40 are arranged on the circumference.

The configuration of the component imaging camera 39 will be described with reference to FIG. The component imaging camera 39 has a first light source unit 39A that projects line-shaped light extending in the Y direction (main scanning direction) onto the lower surface of the component E from diagonally below, and a light receiving unit 39B that receives the light reflected by the component E. And have.

As described above, the component imaging camera 39 is also used for measuring the height of the component E. As will be described in detail later, in the present embodiment, the line-shaped pattern light 65 (relative between a plurality of wavelengths) in which the hue, which is one of the three attributes (hue, saturation, and lightness) of the color, is continuously changed. An example of a pattern light whose brightness is continuously changing) is projected onto the component E, and the height is measured. That is, the pattern light 65 can be said to be a pattern light in which the hue continuously changes in one direction on a plane having an inclination angle with respect to the optical axis of the pattern light 65.

The first light source unit 39A is configured as a color liquid crystal projector for projecting the pattern light 65. The first light source unit 39A is not limited to the color liquid crystal projector as long as it can project the pattern light 65. For example, the first light source unit 39A may be a projector that projects a pattern image drawn on a transparent sheet.

The light receiving unit 39B has three rows of line sensors (not shown) in which a plurality of light receiving elements are arranged in a row in the Y direction (main scanning direction). Each row is arranged in parallel with each other, and a color filter is provided to transmit only light of a wavelength (color) different from that of the other rows among R (red), G (green), and B (blue). There is. The three-row linear sensor is an example of the first light receiving unit.

One pixel in which the density used in the calculation is detected is an adjacent light receiving element of the above-mentioned three line sensors. As will be described in detail later, the component imaging camera 39 images the component E passing above in chronological order. At this time, the component imaging camera 39 receives the light by slightly shifting the timing at which each line sensor receives the light so that the light reflected at the same location of the component E is incident on each line sensor. Therefore, the three light receiving elements can be regarded as one pixel. If more accuracy is required, the light on one line may be simultaneously distributed to each line sensor by a prism or the like.

The pattern light 65 reflected by the component E is received by the line sensor, and an analog voltage corresponding to the amount of light received by each light receiving element is output to the image processing unit 53 (see FIG. 6). The component imaging camera 39 may convert the analog voltage into digital data (density) and output it to the image processing unit 53.

As shown in FIG. 5, the control unit 33 controls the head transport unit 37, and the component E moves above the component imaging camera 39 from the upstream side to the downstream side (or from the downstream side to the upstream side) in the X direction (sub-scanning direction). The head unit 36 is conveyed so as to pass toward. The component imaging camera 39 images the entire component E by imaging the component E passing above in chronological order.

(1-2) Electrical Configuration of Surface Mounter The electrical configuration of the surface mounter 15 will be described with reference to FIG. The surface mounter 15 includes a control unit 33 and an operation unit 34.
The control unit 33 includes an arithmetic processing unit 50, a motor control unit 51, a storage unit 52, an image processing unit 53, an external input / output unit 54, a feeder communication unit 55, and the like.

The arithmetic processing unit 50 includes a CPU, a ROM, a RAM, and the like. A control program and various data are stored in the ROM. The CPU controls each part of the surface mounter 15 by executing a control program. The RAM is used as a main storage device for the CPU to execute various processes.

The motor control unit 51 rotates each motor such as the X-axis servomotor 56, the Y-axis servomotor 57, the Z-axis servomotor 58, the R-axis servomotor 59, and the conveyor drive motor 60 under the control of the arithmetic processing unit 50.
The storage unit 52 is an external storage device that uses a hard disk, a non-volatile memory, or the like as a storage medium. The storage unit 52 stores various data such as a production program that defines the operation of the surface mounter 15. The production program defines information on the number of boards W to be produced, information on the product type, information on the mounting coordinates and mounting angle of the component E, information on the mounting order of the component E, and the like.

The image processing unit 53 creates color image data by converting the analog voltage output from the substrate imaging camera 38 and the component imaging camera 39 into digital data (density) of 256 gradations of 0 to 255 for each RGB. The image processing unit 53 is adjusted so that when the received amount of light of each wavelength is a predetermined value, it is output as the maximum gradation. Further, the maximum amount of light of each wavelength of the pattern light 65 projected by the first light source unit 39A of the component imaging camera 39 is adjusted to be the maximum gradation of 256 gradations.
When the substrate image pickup camera 38 or the component image pickup camera 39 directly outputs digital data (density), the image processing unit 53 is unnecessary.

The external input / output unit 54 is a so-called interface, and is configured to capture detection signals output from various sensors 67 provided on the surface mounter 15. Further, the external input / output unit 54 is configured to control the operation of various actuators 68 based on the control signal output from the arithmetic processing unit 50.

The feeder communication unit 55 is an interface for the arithmetic processing unit 50 to communicate with the feeder 35.
The operation unit 34 includes a display device such as a liquid crystal display and an input device such as a touch panel, a keyboard, and a mouse. The operator can operate the operation unit 34 to make various settings.

(2) Coplanarity In FIG. 4, SOP (Small Outline Package) is shown as an example of component E. The SOP has lead electrodes 61 on two opposite sides of the component body. If the height of the lowermost surface of each lead electrode 61 varies, a part of the lead electrodes 61 may not come into contact with the substrate W when the component E is mounted on the substrate W, which may result in mounting failure.

Therefore, the control unit 33 measures the height of the lowermost surface of each lead electrode 61 using the component imaging camera 39, and determines the uniformity of the height of the lowermost surface of each lead electrode 61 (so-called coplanarity). When the coplanarity is poor (that is, when the height of the lowermost surface has a large variation), the control unit 33 disposes the component E in the disposal box as a component defect.

Here, in FIG. 4, the plane 62 is a plane on which the lower end surface of the suction nozzle 40B is located when measuring the height of the component E. In the following description, the plane 62 is referred to as a reference plane 62. The reference plane 62 is perpendicular to the optical axis of the light receiving unit 39B, that is, the straight line of the light receiving element of the three line sensors (or the plane of the light receiving element of the area sensor when the light receiving unit 39B has the area sensor). ) Is preferable. If there is an inclination with respect to the plane perpendicular to the optical axis of the light receiving unit 39B, the inclination may be corrected.

In the following description, the vertical distance between an arbitrary point on the lower surface of the component E and the reference plane 62 is referred to as the height of that point. In the present embodiment, the height can be measured regardless of whether the lower surface of the component E is above or below the reference plane 62. When the lower surface of the component E is above the reference plane 62, the height is negative. The height can also be said to be the amount of displacement with respect to the reference plane 62.

Here, SOP has been described as an example of component E, but component E is not limited to SOP. For example, the component E may be a QFP (Quad Flat Package) or a BGA (Ball Grid Array) having a plurality of solder balls on the lower surface.

(3) Height measurement using a component imaging camera In the following description, it is assumed that the color of the lower surface of the component E (the surface on which the pattern light 65 is projected) is achromatic. Achromatic color is a color obtained by mixing white and black, and includes white, black, and gray. The reason for limiting to achromatic colors is that the hue (in other words, the relative brightness of light of each wavelength) changes when the pattern light 65 consisting of three wavelengths of RGB is reflected on the chromatic surface, so the height is changed. This is because it cannot be measured accurately.

(3-1) Hue First, the hue will be described with reference to FIG. 7. As described above, hue is one of the three attributes of color (hue, saturation, and lightness), and is also called hue or hue. Saturation is the vividness of a color, and lightness is the lightness (brightness) of a color. It can also be said that the hue is the remainder of the color after removing the saturation element and the lightness element.

・・・ 式１The hue circle schematically shown in FIG. 7 is a ring representation of the hue. In FIG. 7, R is red, Y is yellow, G is green, C is cyan, B is blue, and M is magenta. In the following description, the counterclockwise angle starting from red in the color wheel is referred to as the hue value. In the case of the HSV color system, the hue value can be calculated from the following equation 1. Equation 1 is an example of a predetermined arithmetic expression, and the hue value is an example of an arithmetic value of a predetermined arithmetic expression.

・ ・ ・ Equation 1

The pattern light 65 shown in FIG. 4 is obtained by repeating two cycles of continuously and uniquely changing the hue from 0 degree to 360 degree from the front side to the rear side in the Y direction (an example of a predetermined direction). .. Since the hue changes continuously and uniquely within the same cycle (in other words, the same hue does not appear twice), all the hue values are calculated for each pixel by receiving the pattern light for one cycle of the hue. The hue value of is a unique value.

Further, since the hue is the remainder after removing the saturation element and the lightness element from the color, the calculated hue value is the brightness of the component E (the brightness of whether the surface color is white, black, or gray) or the brightness. The brightness of the light source (the brightness of the entire light source including the case where the brightness is different due to the difference in distance from the light source, etc., and it is affected even if the height of the imaging target is partially different and the brightness is different. Not affected by).

For example, when projecting light of a predetermined hue (light having a predetermined ratio of light amounts between wavelengths of R, G, and B) onto component E and receiving the light reflected by component E to calculate a hue value. If the hue of the projected light is the same, the calculated hue value will be the same even if the brightness of the component E or the brightness of the light source is changed.

(3-2) Generation of Pattern Light A method for generating pattern light 65 will be described with reference to FIGS. 8 and 9. There are various methods for generating the pattern light 65, and here, a method using the trapezoidal wave shown in FIG. 8 and a method using the sine wave shown in FIG. 9 will be described.

(3-2-1) Method using trapezoidal wave FIG. 8 (A) is an example of a trapezoidal wave. FIG. 8B shows a color image captured by projecting the pattern light 65 generated by using the trapezoidal wave shown in FIG. 8A onto the reference plane 62. Here, it is assumed that the brightness of light is represented by 256 gradations from 0 (black) to 255 (white).

As shown in FIG. 8A, in the method using the trapezoidal wave, the brightness of the light of each color of RGB is changed into a trapezoidal shape, and their phases are shifted by 1/3 (= 120 degrees) and superposed. Specifically, in the example shown in FIG. 8A, one cycle (360 degrees) of hue is divided into six equal parts. The brightness of red light changes linearly from 0 to 60 degrees to 255, 60 to 120 degrees from 255 to 0, and 120 to 240 degrees from 0, 240 to 300 degrees. In the section of, it changes linearly from 0 to 255, and in the section of 300 degrees to 360 degrees, it is 255.

The brightness of green light changes linearly from 0 to 255 in the section from 0 to 60 degrees, 255 in the section from 60 degrees to 180 degrees, and linearly from 255 to 0 in the section from 180 degrees to 240 degrees. The change is 0 in the section of 240 degrees to 360 degrees.
The brightness of blue light changes linearly from 0 to 0 in the section of 0 to 120 degrees, from 0 to 255 in the section of 120 to 180 degrees, and 255 and 300 to 360 degrees in the section of 180 to 300 degrees. In the section of, it changes linearly from 255 to 0.

Although the trapezoidal wave has been described here as an example, it may be other than the trapezoidal wave as long as the waveform of any of RGB is continuously changed. For example, it may be an isosceles triangle (preferably symmetrical). Further, it does not have to be symmetrical (extremely sawtooth wave). Further, in the section where the brightness of at least one of the RGB lights changes continuously like the trapezoidal wave described above, the brightness of the light of other colors does not have to change.

(3-2-2) Method using sine wave FIG. 9 (A) is an example of a sine wave. FIG. 9B shows a color image captured by projecting the pattern light 65 generated by using the sine wave shown in FIG. 9A onto the reference plane 62. As shown in FIG. 9A, in the method using a sine wave, the brightness of the light of each color of RGB is changed by the sine wave, and the phase is 1/3 so that the sum of the brightness of RGB is always constant. (= 120 degrees) shift each and overlap.

In the example shown in FIG. 9A, the brightness of the red light becomes 255 at 0 degrees and 360 degrees, and becomes 0 at 180 degrees. The green light is 120 degrees out of phase with the red light, and the brightness becomes 255 at 120 degrees and 0 at 300 degrees. The blue light is 240 degrees out of phase with the red light, and the brightness becomes 0 at 60 degrees and the brightness becomes 255 at 240 degrees.

The light source unit 39A repeats projecting a pattern light 65 of one cycle of a trapezoidal wave or a sine wave over a predetermined length on a reference plane 62 separated by a predetermined distance for two cycles, and the predetermined length is designed. It is stored in the storage unit 52 as a value. Further, since the light source unit 39A is fixed to the reference plane 62, the pattern light 65 is formed at a predetermined position on the reference plane 62. Therefore, by determining the predetermined origin position in the direction in which the brightness of the light of each wavelength of the pattern light 65 continuously changes, the predetermined phase position of the pattern light 65 is located at the corresponding predetermined distance from the origin. It will be.

(3-3) Height measurement procedure As shown in FIG. 10, for convenience, a case where parts E1 and E2 are simultaneously imaged and their heights are measured will be described as an example (usually, the case where they are measured) will be described. The parts E adsorbed on the mounting head 40 are imaged one by one). Further, here, a case where one cycle of pattern light 65 is phase-connected and two cycles of pattern light 65 (trapezoidal wave shown in FIG. 8 or sine wave shown in FIG. 9) is projected will be described as an example.

The image 70 shown in FIG. 11 is a color image (an example of an image) obtained by capturing the component E1 and the component E2 on which the pattern light 65 shown in FIG. 10 is projected by the component imaging camera 39. The density of each pixel of the color image 70 for each RGB is represented by 256 gradations of 0 to 255, respectively. In the color image 70, the rectangular region 71 shows the lower surface of the component E1, and the rectangular region 72 shows the lower surface of the component E2.

Since the pattern light 65 is projected obliquely, a shadow of the component E is formed in the color image 70, but the shadow is omitted in the color image 70 for simplification. Further, depending on the shape of the component E, a shadow may be cast on the rectangular region 71 or the rectangular region 72, but since the lower surface of the component E shown in FIG. 11 is flat, no shadow is cast on the rectangular region 71 or the rectangular region 72. ..

In the image 73, an achromatic (for example, white) reference plate (not shown) is arranged so as to coincide with the reference plane 62, and in that state, the component imaging camera 39 captures the reference plate on which the pattern light 65 shown in FIG. 10 is projected. This is an image displayed by converting the resulting color image into a hue value by the above-mentioned equation 1 and further converting the hue value into brightness (density). Hereinafter, a map in which these hue values are stored for each position in the reference plane 62 is referred to as a reference plane hue map. The position in the reference plane 62 is represented by the position of the pixel of the component imaging camera 39.

The density of each pixel of the image 73 in which the reference plane hue map is displayed in lightness is represented by 360 gradations of 0 to 359 degrees. In the first embodiment, it is assumed that the reference plane hue map is created in advance at the time of shipment from the factory of the surface mounter 15 and stored in the storage unit 52.
In the creation of the reference plane hue map, an elongated achromatic (for example, white) reference plate extending in the Y direction having a size for projecting one line of pattern light 65 is arranged so as to overlap the reference plane 62. Then, one line of pattern light 65 is projected onto the reference plate by the component imaging camera 39, and one line of reference plane hue is obtained from the amount of light received by the line sensor for each wavelength of the pattern light 65 reflected by the reference plate. The map is created. The image 73 shown in FIG. 7 is obtained by arranging a plurality of images showing a reference plane hue map for one line extending in the Y direction in parallel in the X direction, and the reference plane hue map stored in the storage unit 52 is one line. Only minutes.

As described above, the image 73 shows an example of the reference plane map as an image. In the reference plane hue map, the pattern light 65 having the theoretical value shown in FIG. 8 or 9 was projected onto the reference plane 62 without capturing the pattern light projected on the reference plate corresponding to the reference plane 62. Assuming a case, the RGB value for each position may be calculated by Equation 1 and stored for each position. Each position may be stored for each pixel of the assumed component imaging camera 39, or may be stored for each distance interval different from that.
Further, the hue value of each position may be obtained by calculation when calculating the height of the object without storing it as a reference plane map in advance.

Graph 74 is a graph showing the hue values of the pixels on the straight line 75 of the image 73 showing the reference plane hue map. The horizontal axis of the graph 74 is the number of pixels indicating the position on the reference plane (that is, the distance from the reference position on the reference plane 62), and the vertical axis is the hue value of 0 to 359 degrees.
As shown in Graph 74, the hue of the pattern light 65 changes substantially linearly (approximately linearly) within one cycle (that is, the hue changes continuously and uniquely within one cycle). It should be noted that the pattern light 65 only needs to continuously and uniquely change the hue within one cycle, and is not necessarily limited to the one that changes linearly.

The image 76 is an image in which the density of each pixel of the color image 70 for each RGB is converted into a hue value by the above-mentioned formula 1 (to be exact, it is a black-and-white image in which the hue value is further converted into lightness (density). Hereinafter, the hue conversion is performed. Image 76). The density of each pixel of the hue-converted image 76 is also represented by 360 gradations.
Graph 77 is a graph showing the hue values of the pixels on the straight line 78 of the hue-converted image 76. The horizontal axis of the graph 77 is the number of pixels indicating the position on the reference plane, and the vertical axis is the hue value of 0 to 359 degrees.

The image 79 is an image obtained by subtracting the hue value of the corresponding pixel of the image 73 showing the reference plane hue map from the hue value of each pixel of the hue-converted image 76 (hereinafter, referred to as a hue difference image 79).
Graph 80 is a graph showing the hue values of the pixels on the straight line 81 of the hue difference image 79. The horizontal axis of the graph 80 is the number of pixels, and the vertical axis is the hue value of 0 to 359 degrees. It is assumed that the straight lines 75, 78, and 81 are the same straight lines on the reference plane 62.

For example, consider the position (pixel number) P1 in the X direction (horizontal axis direction) of the graph 77 of the hue-converted image 76. For convenience, it is assumed here that the hue value at position P1 is 200 degrees. In the graph 74 of the image 73 showing the reference plane hue map, the position where the hue value is 200 degrees is the position P2. That is, the light received at the position P2 without the component E1 is received at the position P1 due to the presence of the component E1.

In this case, as shown in FIG. 12, assuming that the inclination of the pattern light 65 projected from the first light source unit 39A is θ, the distance (number of pixels) between the position P1 and the position P2 and the inclination θ of the pattern light 65 The height of the component E1 at the position P1 can be calculated from. Specifically, the height can be calculated by Equation 2 shown below.
Height = distance between position P1 and position P2 x tan θ ・ ・ ・ Equation 2

The unit of height calculated by the above equation 2 is the number of pixels. The unit can be converted from the number of pixels to the distance [m] on the reference plane 62 by multiplying by a predetermined proportional coefficient.

When the pattern light 65 is not parallel light, the inclination θ of the pattern light 65 differs depending on the position in the region where the pattern light 65 is projected. Therefore, when the pattern light 65 is not parallel light, the inclination θ may be corrected according to the position.

By the way, as shown in the graph 74 of the reference plane hue map of the image 73, in the present embodiment, the position (pixel number) and the hue value correspond substantially linearly, so that the position of the image 73 in the reference plane hue map The difference (hue difference) between the hue value of P1 and the hue value of the position P1 in the hue-converted image 76 is substantially directly proportional to the distance between the position P1 and the position P2. Therefore, in the present embodiment, the control unit 33 calculates the height of the position P1 not from the distance between the position P1 and the position P2 but from the hue difference.

Specifically, when the control unit 33 considers that the difference (hue difference) between the hue value of the position P1 and the hue value of the position P1 in the hue conversion image 76 is directly proportional to the distance between the position P1 and the position P2. Obtains the hue difference at the position P1 from the hue difference image 79, and calculates the height by the following equation 3.
Height = hue difference x tan θ ・ ・ ・ Equation 3

Since there is a proportional relationship between the hue difference and the distance, the unit of height calculated by the above equation 3 is equivalent to the number of pixels. Therefore, the unit can be converted into the number of pixels by multiplying by a predetermined proportional coefficient. It can also be converted to a distance [m] on the reference plane 62 by multiplying by another proportional coefficient.

The position (pixel number) and the hue value may have a one-to-one correspondence, and may not necessarily correspond linearly. When the position and the hue value do not correspond linearly, the height may be calculated by the above-mentioned equation 2. That is, the hue value of the position P1 may be acquired, the position P2 having the same hue value as this hue value may be searched from the hue value stored in the reference plane hue map, and the calculation may be performed by Equation 2.

(4) Creation of a multi-valued image showing the brightness of the component As shown in FIG. 13, the figure 85 such as characters and polarity marks on the lower surface of the component E is different from the brightness (brightness) of the lower surface of the component E. It may be written as. The control unit 33 creates a multi-valued image representing the brightness of the lower surface of the component E from the color image 70 created in the process of measuring the height of the component E, analyzes the created multi-valued image, and draws the figure 85. recognize.

Hereinafter, a method of creating a multi-valued image representing the brightness of the lower surface of the component E from the color image 70 will be described. The method of creating the multi-valued image differs depending on the method of creating the pattern light 65. Here, a method of creating a multi-valued image will be described for each method of creating the pattern light 65.

(4-1) When pattern light is created using a trapezoidal wave As shown in FIG. 8A described above, the trapezoidal wave always has the maximum value of any of RGB. Therefore, as shown in Equation 4 below, the control unit 33 creates a multi-valued image by acquiring the maximum value of RGB brightness (density) for each pixel from the color image 70. In the case of the trapezoidal wave of FIG. 8A, since the maximum value for each position (pixel) is always the maximum density, a constant brightness can be obtained.
Brightness = Max (R, G, B) ・ ・ ・ Equation 4

(4-2) When pattern light is created using a sine wave As shown in FIG. 9A described above, the sum of the brightness of RGB is always constant in the sine wave. Therefore, as shown in the following equation 5, the control unit 33 creates a multi-valued image by acquiring the sum of the brightness (density) of RGB for each pixel from the color image 70.
Brightness = R + G + B ・ ・ ・ Equation 5

(5) Effect of the Embodiment According to the three-dimensional measuring apparatus (component imaging camera 39 and control unit 33) according to the first embodiment, the pattern light 65 whose hue is continuously changing is projected onto the component E. When the pattern light 65 is used, the hue value becomes a unique value for each position regardless of the brightness of the component E or the brightness of the pattern light 65 itself, so that the same region does not need to be imaged multiple times as in the phase shift method. The height can be measured. In addition, the height can be measured without moving and imaging the line by the number of pixels in the direction orthogonal to the line as in the optical cutting method. Therefore, the height of the component E can be measured in a shorter time than the phase shift method or the optical cutting method.

According to the three-dimensional measuring device, since the line sensor is used as the light receiving unit 39B, the imaging range can be changed according to the size of the component E by changing the amount of movement that relatively moves the component imaging camera 39 and the component E. can. Further, since the irradiation range of the pattern light 65 can be narrowed, the size of the three-dimensional measuring device can be reduced.

According to the three-dimensional measuring device, a multi-valued image showing the brightness of the lower surface of the component E is created from the color image 70 created in the process of measuring the height of the component E, so that the entire component E can be imaged once. , The height of the component E can be measured and the figure 85 shown on the lower surface of the component E can be recognized.

<Embodiment 2>
In the first embodiment described above, the first light source unit 39A projects a line-shaped pattern light, and a line sensor is used as the light receiving unit 39B. Then, in the first embodiment, the reference plane hue map for one line is stored in the storage unit 52.

On the other hand, the first light source unit 39A according to the second embodiment projects a planar pattern light, and the light receiving unit 39B is a color in which light receiving elements of each color of RGB are two-dimensionally arranged in a predetermined arrangement pattern. It is an area sensor (hereinafter, simply referred to as an area sensor). In the second embodiment, a reference plane hue map is created using a planar reference plate. Specifically, the first light source unit 39A projects the planar pattern light onto the planar reference plate, and the pattern light reflected by the reference plate is received by the area sensor for each wavelength based on the amount of light received. A reference plane hue map is created.

Since the reference plane hue map according to the second embodiment is two-dimensional data, the amount of data is larger than that of the reference plane hue map of the first embodiment. Therefore, in the second embodiment, the amount of data of the reference plane hue map is reduced and stored. Here, two methods will be described as methods for reducing the amount of data in the reference plane hue map.

(1) Method 1
Method 1 will be described with reference to FIG. 14 (A). In the method 1, in the reference plane hue map created by imaging the reference plate, the direction in which the brightness of the light of each wavelength of the pattern light changes (horizontal direction in FIG. 14) is defined as the row direction, and the direction is defined as the row direction. When the orthogonal direction (vertical direction in FIG. 14) is defined as the column direction, the storage unit 52 stores an average value (hereinafter, referred to as a representative hue value) obtained by averaging the hue values for each column.

The control unit 33 uses the representative hue value for each column stored in the storage unit 52 as the reference plane hue map. Specifically, the control unit 33 creates the hue difference image 79 by subtracting the representative hue value of the column in which the pixel is located from each pixel of the hue conversion image 76.

(2) Method 2
Method 2 will be described with reference to FIG. 14 (B). When the reference plane 62 is imaged, the relative angle between the first light source unit 39A and the light receiving unit 39B is deviated, so that the reference plane hue is obtained for the obliquely inclined plane portion as shown in FIG. 14 (B). A map may be created. In this case, if only the representative hue value of each column is stored in the storage unit 52 as in method 1, the hue value of the upper part of the reference plane hue map (an example of one end in the column direction) and the lower part of the reference plane hue map. The hue value of (an example of the other end in the column direction) is significantly different from the representative hue value.

Therefore, in the method 2, in the reference plane hue map created by imaging the reference plate, the average value of the hue values is stored for each column for a predetermined number of rows (for example, 2 to 3 rows) at the upper part of the reference plane hue map. In addition to storing in the storage unit 52, the storage unit 52 stores the average value of the hue values for each column for a predetermined number of rows at the bottom of the reference plane hue map.
The control unit 33 is based on the average value for each column of a predetermined number of rows at the top of the reference plane hue map stored in the storage unit 52 and the average value for each column of a predetermined number of rows at the bottom of the reference plane hue map. A diagonally tilted reference plane hue map is restored by linearly interpolating each row of the hue map.

(3) Effect of the Embodiment According to the method 1, since the average value (representative hue value) obtained by averaging the hue values for each column is stored in the storage unit 52, the amount of data stored in the storage unit 52 is the reference plane hue map. It is the amount of data for one line. Therefore, the storage area of the storage unit 52 can be saved as compared with the case where the entire reference plane hue map is stored.

According to the method 2, the storage unit 52 stores the average value for each column of a predetermined number of rows at one end in the column direction and the average value for each column of a predetermined number of rows at the other end. The storage area of the storage unit 52 can be saved as compared with the case where the entire reference plane hue map is stored. Then, according to the method 2, since the reference plane hue map is restored from the average value thereof, the reference plane hue map in the tilted state can be restored. Therefore, the height can be accurately measured even if the relative angle between the first light source unit 39A and the light receiving unit 39B is tilted.

<Embodiment 3>
In the first embodiment described above, a case where a reference plane hue map is created by imaging a reference plate has been described as an example. In the third embodiment, another method of creating a reference plane hue map will be described.

(1) Other method 1
The other method 1 is a method of creating a reference plane hue map by calculation. Specifically, for example, the control unit 33 converts the brightness (0 to 255) of the light of each of the RGB colors shown in FIGS. 8 (A) and 9 (A) described above into a hue value for each angle, thereby converting the reference plane. Create a hue map logically. For example, in the case of 120 degrees shown in FIG. 8A, the control unit 33 converts the brightness (0,255,0) of the light of each RGB color at 120 degrees into a hue value by substituting it into the above equation 1.

The above-mentioned 120 degrees is a phase value. The phase value is the position on the reference plane 62, that is, the distance from the phase origin (for example, X). The brightness of the light of each color of RGB at the distance X is a function of a trapezoidal wave or a sine wave. Therefore, the hue value is represented by a function of distance X. Since the hue value is a function of the distance X, the position where the hue value should be can be calculated from the hue value. As described above, the reference plane hue map may be stored from now on, or only the calculation formula may be stored without being stored in the reference plane hue map.

In the other method 1, the first light source unit 39A can faithfully reproduce the calculated hue value (design value) of the pattern light 65, and the light receiving unit 39B also receives the pattern light 65 to obtain the above-mentioned design value. It can be applied when it can be faithfully reproduced (or when it can be considered that it can be faithfully reproduced).

(2) Other method 2
Another method 2 will be described with reference to FIG. In the other method 2, an elongated achromatic (for example, white) reference plate 87 extending in the Y direction is arranged on the left side of the imaging range 86 of the component imaging camera 39, the right side of the imaging range 86, or both. The control unit 33 creates a partial map by calculating the hue value from the density of each pixel converted from the amount of light received by the pattern light 65 reflected by the reference plate 87 for each wavelength. Then, the control unit 33 creates a reference plane hue map by interpolating other parts of the reference plane hue map from the created partial map in the same manner as in the method 1 and method 2 of the above-described second embodiment.

(3) Effect of the Embodiment Since the reference plane hue map does not have to be stored in the storage unit 52 in the other method 1, the storage area of the storage unit 52 can be saved. Further, in the other method 1, since the reference plane hue map is created without using the reference plate, the reference plane hue map can be created with a simpler configuration than the case where the reference plate is used.

In the other method 2, since the reference plane hue map does not have to be stored in the storage unit 52, the storage area of the storage unit 52 can be saved. Further, in the other method 2, the reference plate 87 can be made smaller than the case where a large reference plate capable of creating the entire reference plane hue map at one time is used. Further, in the other method 2, the reference plate 87 is periodically imaged to create a reference plane hue map (or the reference plate 87 is imaged each time the height of the component E is measured, and the reference plane hue is captured. By creating a map), it is possible to suppress a decrease in measurement accuracy even if the brightness of the first light source unit 39A and the light receiving sensitivity of the light receiving unit 39B change with time.

<Embodiment 4>
In the first embodiment described above, the hues of one cycle are connected in phase to project the pattern light 65 for a plurality of cycles. On the other hand, in the fourth embodiment, the pattern light whose hue changes continuously and periodically and whose saturation value (brightness fluctuation range) is different for each cycle is projected.

(1) Generation of pattern light Examples of the method of generating the pattern light described above include a method using a trapezoidal wave, a method using a sine wave, and a method using an independent wave. Hereinafter, each method will be described. In the following description, RGB will be described as an example of the wavelength of the pattern light, but the wavelength is not limited to RGB.

(1-1) Method using trapezoidal wave FIG. 16A is an example of a trapezoidal wave. FIG. 16B shows a color image captured by projecting the pattern light generated by using the trapezoidal wave shown in FIG. 16A onto the reference plane 62.
As shown in FIG. 16 (A), in the method using the trapezoidal wave, the brightness of the upper side of the trapezoid is set to 255 in any cycle, and the brightness of the lower side of the trapezoid is gradually lowered as one cycle elapses. do. Specifically, in the example shown in FIG. 16A, the brightness of the lower side of the trapezoid is 150 in the first cycle, 100 in the second cycle, 50 in the third cycle, and 0 in the fourth cycle. The brightness of the lower side is gradually decreasing.

・・・ 式６When using a trapezoidal wave, the hue value, lightness value, and saturation value can be calculated from the following formulas. Equation 6 is an example of a predetermined arithmetic expression.

・ ・ ・ Equation 6

・・・ 式８Brightness value = MAX (R, G, B) ・ ・ ・ Equation 7

・ ・ ・ Equation 8

(1-2) Method using sine wave FIG. 17 (A) is an example of a sine wave. FIG. 17B shows a color image captured by projecting the pattern light generated by using the sine wave shown in FIG. 17A onto the reference plane 62. As shown in FIG. 17A, in the method using a sine wave, the amplitude (brightness fluctuation range) of the sine wave is gradually increased every time one cycle elapses.

・・・ 式９When using a sine wave, the hue value, lightness value, and saturation value can be calculated from the following equations. Equation 9 is an example of a predetermined arithmetic expression.

・ ・ ・ Equation 9

・・・ 式１１Brightness value = R + G + B ・ ・ ・ Equation 10

・ ・ ・ Equation 11

(1-3) Method using independent wave FIG. 18 (A) is an example of an independent wave. FIG. 18B shows a color image captured by projecting the pattern light generated by using the independent wave shown in FIG. 18A onto the reference plane 62. As shown in FIG. 18A, in the method using an independent wave, the brightness is changed in a change pattern different from each other for each of RGB. Specifically, in the example shown in FIG. 18A, the brightness of red is constant at 255. The brightness of green changes linearly so that the beginning of the cycle is 0 and the brightness becomes 255 at the end of the cycle. The brightness of blue gradually increases with each cycle.

When using an independent wave, the hue value, lightness value, and saturation value can be calculated from the following formulas. Equation 12 is an example of a predetermined arithmetic expression.
Hue value = G / R ・ ・ ・ Equation 12
Lightness = R ・ ・ ・ Equation 13
Saturation value = B / R ・ ・ ・ Equation 14

In the above example, R (red) is used as the brightness and a constant value (reference) is used, G (green) is used as the hue and the hue is continuously changed, and B (blue) is used as the saturation and the saturation is changed stepwise. , Which color (wavelength) should be used as hue, lightness, or saturation can be appropriately determined.

(2) Height measurement procedure The image 90 shown in FIG. 19 is a color image obtained by capturing the reference plane 62 on which the above-mentioned pattern light is projected. For convenience, component E is omitted in FIG.
The image 91 is an image converted from the color image 90 (hereinafter, referred to as a hue-converted image 91). Graph 92 is a graph showing the hue values of the pixels on the straight line 93 of the hue conversion image 91. As shown in Graph 92, the hue value of the pixels of the hue-converted image 91 changes linearly from 0 degrees to 360 degrees in each cycle.

The image 94 is an image representing the saturation value converted from the color image 90 (hereinafter, referred to as a saturation conversion image 94). In the case of the HSV color system, the saturation value can be calculated from the above-mentioned equation 8. Graph 95 is a graph showing the saturation value of the pixel on the straight line 96 of the saturation conversion image 94. As shown in Graph 95, the saturation value of the pixel of the saturation conversion image 94 is constant within one cycle, and gradually increases as one cycle elapses.

The image 97 is an image obtained by correcting the hue-converted image 76 based on the saturation-converted image 94 (hereinafter, referred to as a corrected hue image 97). Specifically, in the corrected hue image 97, as shown in the following equations 15 to 17, 360 each time the saturation value of the saturation conversion image 94 changes to the hue value of each pixel of the hue conversion image 91. It is an image corrected by adding.
S0: Corrected hue value = hue value +0 ... Equation 15
S1: Corrected hue value = hue value + 360 ... Equation 16
S2: Corrected hue value = hue value +720 ... Equation 17

Graph 98 is a graph showing the hue values of the pixels on the straight line 99 of the corrected hue image 97. As shown in Graph 98, the hue value of each pixel of the corrected hue image 97 becomes a unique value over the entire period. Graph 98 is a completely linear linear function if the pattern light 65 is as theoretical and the light receiving unit 39B is as theoretical.

(2) Effect of Embodiment According to the three-dimensional measuring apparatus according to the fourth embodiment, the hue of the pattern light changes continuously and periodically, and the saturation value (brightness fluctuation range) changes every cycle. ) Are different, so even if the same calculated value is calculated in each cycle, it is possible to specify which cycle the calculated value is from the difference in saturation value. Therefore, even if the height of the component E exceeds the width of one cycle of the pattern light, the height of the measurement target can be measured by one imaging.

<Embodiment 5>
In the fifth embodiment, the direction in which the component imaging camera 39 projects the pattern light 65 onto the component E is relatively changed, and the component imaging camera 39 images the component E in each direction. Specifically, as described above, the head unit 36 includes an R-axis servomotor 59 that rotates the mounting head 40 that attracts the component E around the axis. The control unit 33 rotates the component E by rotating the mounting head 40 about an axis. As a result, the direction in which the component imaging camera 39 projects the pattern light 65 onto the component E is changed. The control unit 33 images the component E by the component imaging camera 39 in a plurality of directions (for example, 0 degree and 180 degrees).

The direction in which the pattern light 65 is projected is not limited to two directions, and may be projected from three or more directions. However, in order to measure the height accurately, it is desirable to include at least two opposite directions (for example, 0 degree and 180 degree).

FIG. 20 (A) shows a color image captured at 0 degrees, and FIG. 20 (B) shows a color image captured at 180 degrees. In FIG. 20 (A), there is a shadow portion on the right side of the component E where the pattern light 65 is not projected, but in FIG. 20 (B), since the pattern light 65 is projected from the opposite side, the shadow on the right side of the component E is formed. Has disappeared. The control unit 33 measures the height of the component E by using these two color images.

According to the three-dimensional measuring device according to the fifth embodiment, since the direction in which the pattern light 65 is projected onto the component E is relatively changed to project the pattern light 65 in order from at least two directions, the direction in which the pattern light 65 is projected is different. Compared to the case where there is only one direction, there is a high possibility that the height of the component E can be measured over the entire surface.

Further, according to the three-dimensional measuring device, the direction in which the component imaging camera 39 projects the pattern light 65 onto the component E is relatively changed by using the R-axis servomotor 59, so that the direction can be relatively changed. It is not necessary to provide a separate configuration. Therefore, the cost for changing the direction relatively can be suppressed.

<Embodiment 6>
As shown in FIG. 21, the component imaging camera 39 according to the sixth embodiment includes a second light source unit 101. The second light source unit 101 is also configured as a projector. The second light source unit 101 is a pattern light 102 in which the relative brightness between a plurality of wavelengths is continuously changed, and the wavelength is different from that of the pattern light 65 projected by the first light source unit 39A. The light 102 is projected onto the component E from a direction different from that of the first light source unit 39A (for example, a direction rotated 180 degrees around the axis of the mounting head 40 from the first light source unit 39A).

Here, the wavelengths that are different are wavelengths in a range that does not overlap with the RGB range, for example, a wavelength in the ultraviolet region or a wavelength in the infrared region.
The pattern light 102 may have a wavelength in the RGB range as long as it does not overlap with the pattern light 65 projected by the first light source unit 39A. Here, "does not overlap" means that none of the plurality of wavelengths of the pattern light 102 overlaps between the minimum value and the maximum value of the plurality of wavelengths of the pattern light 65. Further, the pattern light 102 may be visible light (wavelength in the visible region) or invisible light (wavelength in the invisible region).

Further, both the first light source unit 39A and the second light source unit 101 may project invisible light. For example, even if the first light source unit 39A projects a pattern light composed of light having two or more wavelengths in the ultraviolet region, and the second light source unit 101 projects a pattern light composed of light having two or more wavelengths in the infrared region. good.

In addition to the RGB three-row line sensor (an example of the first light receiving unit) described above, the light receiving unit 39B receives a plurality of pattern lights 102 projected by the second light source unit 101 and reflected by the component E. It has a line sensor (an example of a second light receiving unit). These line sensors are provided with a filter that transmits only light having a wavelength different from that of other line sensors among the wavelengths of light constituting the pattern light 102.

Since the wavelengths of the pattern light 65 projected by the first light source unit 39A and the pattern light 102 projected by the second light source unit 101 are different, even if these are projected at the same time, each line sensor is the line sensor. Only the light of the wavelength corresponding to the above can be received. Therefore, in order to shorten the time required for imaging, the control unit 33 simultaneously projects the pattern lights 65 and 102 onto the component E from the first light source unit 39A and the second light source unit 101 to image the component E.
Then, the control unit 33 receives a color image created by receiving the pattern light 65 projected by the first light source unit 39A and an image created by receiving the pattern light 102 projected by the second light source unit 101. The height of the part E is determined using and.

According to the three-dimensional measuring device according to the sixth embodiment, since the pattern lights 65 and 102 are projected onto the component E from two directions, there is a high possibility that the height of the component E can be measured over the entire surface. Further, according to the three-dimensional measuring device, the first light source unit 39A and the second light source unit 101 simultaneously project the pattern lights 65 and 102 onto the component E to image the component E, so that the time required for imaging is shortened. can. Therefore, the height of the component E can be measured in a short time.

<Other embodiments>
The techniques disclosed herein are not limited to the embodiments described above and in the drawings, and for example, the following embodiments are also included in the technical scope disclosed herein.

(1) In the above-described first embodiment, three visible light of RGB are described as a plurality of wavelengths as an example, but the plurality of wavelengths may be wavelengths in an invisible region (for example, near-infrared light). Since the wavelength in the invisible region is not affected (or is not easily affected) by the color of the component E, the height can be measured even if the color of the lower surface of the component E is chromatic. When using a wavelength in the invisible region, it is necessary to match the light receiving wavelength of the light receiving unit 39B with that wavelength.

(2) In the above embodiment, the projector is described as an example as the first light source unit 39A and the second light source unit 101, but these light source units are not limited to the projector. For example, the light source unit may be a diffraction grating, a prism, an optical filter, a multi-color LED sequential arrangement, or the like.

(3) In the above embodiment, three wavelengths have been described as an example of a plurality of wavelengths, but the plurality of wavelengths is not limited to three wavelengths, and may be two or more wavelengths.

(4) In the above embodiment, the HSV color system has been described as an example as the color system of the color image, but the color system is not limited to the HSV color system. For example, the color system may be a YIQ color system, a Lab color system, or the like.

・・・ 式１８In the case of the YIQ color system, the hue value can be calculated by the following equation 18. Equation 18 is an example of a predetermined arithmetic expression.

・ ・ ・ Equation 18

・・・ 式２２In the case of the Lab color system, the hue value can be calculated by the following equations 19 to 22. In Equation 22, Xn, Yn, and Zn are XYZ values in the reference white color. Equations 19 to 22 are examples of predetermined arithmetic expressions.
X = 0.412R + 0.358G + 0.181B ・ ・ ・ Equation 19
Y = 0.213R + 0.715G + 0.072B ・ ・ ・ Equation 20
Z = 0.019R + 0.119G + 0.951B ・ ・ ・ Equation 21

・ ・ ・ Equation 22

FIG. 22 (A) is a graph showing hue values calculated by the HSV color system, the YIQ color system, and the Lab color system. As shown in the figure, each color system is out of phase. FIG. 22B is a graph corrected so that the phases of the respective color systems match.

(5) In the first embodiment, a case where a reference plane hue map created in advance is stored in the storage unit 52 has been described as an example. On the other hand, a large reference plate capable of creating the entire reference plane hue map at one time may be provided, and the reference plane hue map may be created from the reference plate. In this way, the height can be accurately measured even if the accuracy of the first light source unit 39A faithfully reproducing the pattern light and the accuracy of faithfully reproducing the pattern light of the light receiving unit 39B are low.

(6) In the above embodiment, the component imaging camera 39 has been described as an example of the imaging unit, but the imaging unit may be the substrate imaging camera 38.

(7) In the above embodiment, the surface mounter 15 has been described as an example of the work work apparatus, but the work work apparatus is not limited to the surface mounter 15. For example, the work work apparatus may be a screen printing machine 12, a printing inspection machine 13, a dispenser 14, a post-mounting visual inspection machine 16, or a post-curing visual inspection device 18.
For example, in the case of the screen printing machine 12, an image pickup unit having an image pickup surface facing downward and a transfer unit for horizontally transporting the image pickup unit above the substrate W are provided, and the image pickup unit is conveyed to the substrate W. The height of the solder paste printed on the substrate W may be measured by photographing each part of the above.
Further, in the case of the dispenser 14, since the head unit 36 for holding the dispenser head to which the adhesive is applied so as to be movable in the vertical direction and the transport unit for transporting the head unit 36 in the horizontal direction are provided, an image pickup is performed. The height of the adhesive applied to the substrate W is measured by arranging the image pickup unit with the surface facing down on the head unit 36 and transporting the image pickup unit to image each part of the substrate W from above. You may.
The same applies to the printing inspection machine 13, the post-mounting visual inspection machine 16, the post-curing visual inspection device 18, and the like.

15 ... Surface mounting machine (example of work unit), 30 ... Board transfer device (example of working unit), 31 ... Tape parts supply equipment (example of working unit), 32 ... Parts mounting equipment (example of working unit), 33 ... Control unit (an example of a three-dimensional measuring device), 37 ... Head transport unit (an example of a moving unit), 39 ... Parts imaging camera (an example of an imaging unit and a three-dimensional measuring device), 39A ... A first light source unit, 39B ... 1st light receiving unit, 52 ... storage unit, 59 ... R-axis servo motor (example of changing unit), 62 ... reference plane, 65 ... pattern light, 70 ... color image (example of image), 73 ... reference plane Hua map (an example of a reference plane map), 87 ... a reference plate, 90 ... a color image (an example of an image), 100 ... a pattern light, 101 ... a second light source unit, 102 ... a pattern light, E (E1, E2) ... Parts (an example of measurement target)

Claims (17)

It is a three-dimensional measuring device that measures the height of the object to be measured.
Pattern light in which the relative brightness between a plurality of wavelengths continuously changes in a predetermined direction, and the calculated value of a predetermined calculation formula with the brightness of the light of each of the wavelengths as a variable is the brightness. A first light source unit that obliquely projects pattern light that does not overlap within one cycle of the change of light toward a reference plane that serves as a reference for the height of the measurement target from the predetermined direction.
A first light receiving unit that receives the pattern light reflected by the measurement target for each wavelength, and
A control unit that obtains the height of the measurement target based on the amount of light received by the first light receiving unit for each wavelength.
A three-dimensional measuring device equipped with. The three-dimensional measuring device according to claim 1.
The control unit obtains a calculated value of the predetermined calculation formula from the amount of light received by the first light receiving unit for each wavelength, and obtains the height of the measurement target based on the calculated value. Former measuring device. The three-dimensional measuring device according to claim 1 or 2.
A three-dimensional measuring device in which the pattern light is projected onto a predetermined range of the reference plane. The three-dimensional measuring device according to any one of claims 1 to 3.
The first light source unit projects the linear pattern light.
The first light receiving unit is a plurality of line sensors extending in parallel in the main scanning direction.
The three-dimensional measuring device is a three-dimensional measuring device including a moving unit that moves the first light source unit and the line sensor relative to the measurement target in a sub-scanning direction orthogonal to the main scanning direction. The three-dimensional measuring device according to any one of claims 1 to 3.
The first light source unit projects the planar pattern light.
The first light receiving unit is a three-dimensional measuring device which is an area sensor. The three-dimensional measuring device according to any one of claims 1 to 5.
A three-dimensional measuring device in which the plurality of wavelengths are wavelengths outside the visible region. The three-dimensional measuring device according to any one of claims 1 to 6.
A three-dimensional measuring device in which the relative brightness between a plurality of wavelengths of the pattern light changes continuously and periodically, and the fluctuation range of the brightness differs for each period. The three-dimensional measuring device according to claim 2.
The control unit represents the calculated value obtained from the received amount of light received by the first light receiving unit for each wavelength and the calculated value obtained from the brightness of the light of each of the wavelengths of the pattern light. A three-dimensional measuring device that obtains the height of the measurement target based on a reference plane map. The three-dimensional measuring device according to claim 8.
The control unit is a three-dimensional measuring device that creates the reference plane map by obtaining the calculated value from the theoretical brightness of the light of each of the wavelengths of the pattern light by the predetermined calculation formula. The three-dimensional measuring device according to claim 8.
It has a reference plate arranged so as to coincide with the reference plane, and has a reference plate.
The control unit projects the pattern light onto the reference plate by the first light source unit, reflects the pattern light on the reference plate, and receives the pattern light received by the first light receiving unit. A three-dimensional measuring device that creates the reference plane map by obtaining the calculated value from the amount of received light by the predetermined calculation formula. The three-dimensional measuring device according to claim 8.
It has a reference plate arranged so as to coincide with the reference plane, and has a reference plate.
The control unit projects the pattern light onto the reference plate by the first light source unit, reflects the pattern light on the reference plate, and receives the pattern light received by the first light receiving unit. A partial map is created by obtaining the calculated value from the received light amount by the predetermined calculation formula, and the reference plane map is created by interpolating other parts of the reference plane map from the created partial map. A three-dimensional measuring device. The three-dimensional measuring device according to claim 8.
Equipped with a storage unit
The pattern light is projected onto a reference plate arranged so as to coincide with the reference plane by the first light source unit, reflected by the reference plate, and received by the first light receiving unit. In the reference plane map representing the calculated value obtained from the received amount of light for each wavelength by the predetermined calculation formula, a plurality of the calculated values arranged in the direction in which the brightness of the light of each wavelength changes are lined up. When a plurality of the calculated values arranged in a direction orthogonal to the said direction are defined as a column, the storage unit stores the average value obtained by averaging the calculated values for each column.
The control unit receives the amount of light received for each wavelength of the pattern light reflected by the measurement target and received by the first light receiving unit, and the average value for each column stored in the storage unit. A three-dimensional measuring device that obtains the height of the measurement target based on the above. The three-dimensional measuring device according to claim 8.
Equipped with a storage unit
The pattern light is projected onto a reference plate arranged so as to coincide with the reference plane by the first light source unit, reflected by the reference plate, and received by the first light receiving unit. In the reference plane map representing the calculated value obtained from the received amount of light for each wavelength by the predetermined calculation formula, a plurality of the calculated values arranged in the direction in which the brightness of the light of each said wavelength changes are lined up. When a plurality of the calculated values arranged in a direction orthogonal to the direction are defined as columns, the calculated values are averaged for each column for a predetermined number of rows at one end in the column direction in the storage unit. The average value is stored, and the average value obtained by averaging the calculated values for each column for a predetermined number of rows at the other end in the column direction is stored.
The control unit is composed of an average value for each column of the predetermined number of rows at one end stored in the storage unit and an average value for each column of the predetermined number of rows at the other end. A three-dimensional measuring device that restores the reference plane map by interpolating each row of the reference plane map. The three-dimensional measuring device according to any one of claims 1 to 13.
The control unit creates a multi-valued image representing the brightness of the measurement target from the amount of light received for each wavelength of the pattern light reflected by the measurement target and received by the first light receiving unit. , 3D measuring device. The three-dimensional measuring device according to any one of claims 1 to 14.
The first light source unit includes a changing unit that relatively changes the direction in which the pattern light is projected onto the measurement target.
The control unit is a three-dimensional measuring device that projects the pattern light onto the first light source unit in order from at least two directions by relatively changing the direction by the changing unit. The three-dimensional measuring device according to any one of claims 1 to 14.
A second light source unit that obliquely projects the pattern light having a wavelength different from that of the pattern light projected by the first light source unit from a direction different from that of the first light source unit toward the reference plane.
A second light receiving unit that receives the pattern light projected by the second light source unit and reflected by the measurement target for each wavelength.
With
The control unit is a three-dimensional measuring device that simultaneously projects the pattern light onto the first light source unit and the second light source unit. A work unit that performs a predetermined work on the work,
The three-dimensional measuring device according to any one of claims 1 to 16, which measures the height of an object involved in the work.
Work work equipment equipped with.

Images