JP3182924U - Optical detector - Google Patents

Abstract

An optical detection device capable of imaging and detecting even in a place with dust or splashes.
Gas supply holes 198 and 199 supply pressurized gas from a compressed air source to an internal space 192. The gas supplied to the internal space 192 through the gas supply holes 198 and 199 is ejected from the opening 193 to the outside of the housing 191. By ejecting the gas from the opening 193, contamination of the lens of the detection unit 195 or the illumination unit 197 with cutting fluid, shavings, or a mixture thereof can be prevented. Further, the opening 193 serves as an orifice to increase the gas flow velocity and blow off the cutting fluid on the workpiece.
[Selection] Figure 1

Description

  The present invention relates to an optical detection device suitable for use in a place with dust or splashes.

  The positioning of the workpiece has changed from a conventional mechanical type to a mode of XYθ correction after reference imaging. However, in the processing machine, the generation of by-products such as dust and cutting fluid has contaminated the optical system, making reference imaging itself difficult.

  The following Patent Document 1 is an example in which an imaging device for reference imaging is used in a processing machine using a laser, and the subject is imaging + positioning of a galvanometer mirror, and there is no disclosure of by-products. The following Patent Document 2 is an example in which generation of a by-product of the laser processing machine is an issue, and the by-product is sucked directly on the workpiece so that the by-product does not adhere to the Fθ lens through which the laser beam passes. Yes.

  In the case of laser processing, the by-product is smoke-like, but when it is involved in machining, the by-product extends to chips, abrasive grains, polishing cutting fluid and the like. In addition to the processing machine, for example, in the case of an apparatus that handles powder or liquid as a workpiece, the imaging optical system must be arranged at a position that avoids the influence thereof.

  Patent Document 3 below forms an air flow around an objective lens (or fiber end) in order to protect dust and water droplets at the time of seam bonding, and includes an air turbine wheel to generate an air flow. Patent Document 4 below discloses a lens hood in which a transparent body (plate) is placed in front of the objective lens and air can be injected along the transparent body in order to completely prevent foreign matter from adhering to the objective lens. . Patent Document 5 listed below discloses a method of capturing dust or the like in an adhesive by forming a spiral air flow inside a laser guide tube and applying the flow to the adhesive.

JP-A-8-71780 JP 2005-305537 A JP-A-3-158882 JP 2001-108880 A JP 2002-361467 A

  Patent Document 3 has a complicated structure due to the presence of an air turbine wheel, etc., and Patent Document 4 is a structure that further removes foreign matter that cannot be protected only by the air flow by the air flow. Dustproofing and dustproofing outside the objective lens is not disclosed.

  The present invention has been made in view of such a situation, and an object of the present invention is to provide an optical detection device capable of imaging and detecting even in a place with dust or splashes.

One embodiment of the present invention is an optical detection device. This optical detection device
A housing;
An internal space in the housing;
An opening that allows communication between the outside of the housing and the internal space;
A detection unit having an optical axis passing through the internal space and continuing from the opening to the outside of the housing;
A gas supply hole for supplying gas to the internal space,
The gas supplied to the internal space through the gas supply hole is jetted out of the housing from the opening.

  In an optical detection device of a certain aspect, it is preferable to have a means for adjusting the pressure of the gas delivered to the gas supply hole.

  In one aspect of the optical detection device, the optical detection device may include an imaging element and an optical system in a lens barrel.

  The optical detection apparatus of a certain aspect may include an illumination unit that illuminates the outside of the housing from the internal space through the opening.

Another aspect of the present invention is also an optical detection device. This optical detection device
A housing;
An internal space in the housing;
An opening that allows communication between the outside of the housing and the internal space;
An imaging unit including an imaging element and an optical lens having an imaging optical axis that passes through the internal space and extends from the opening to the outside of the housing;
An illumination unit that illuminates the exterior of the housing through the opening from the internal space;
A gas supply hole for supplying gas to the internal space;
And means for adjusting the pressure of the gas delivered to the gas supply hole,
The gas supplied to the internal space through the gas supply hole is jetted out of the housing from the opening.

  In any aspect of the optical detection device, the opening may also serve as an orifice, and the gas in the internal space may be ejected at a high flow rate.

  It should be noted that any combination of the above-described constituent elements, or a conversion of the expression of the present invention between systems or the like is also effective as an aspect of the present invention.

  ADVANTAGE OF THE INVENTION According to this invention, the optical detection apparatus which can image and detect also in a place with dust or a droplet is realizable.

Sectional drawing which shows the 1st structural example of the optical detection apparatus which concerns on embodiment of this invention. The conceptual perspective view of the workpiece | work cutting device which shows the 1st usage example of the optical detection apparatus of FIG. The top view which shows an example of the workpiece | work made into a process target in the 1st usage example. FIG. 3 is a cross-sectional view illustrating another configuration example of the imaging apparatus illustrated in FIG. 2. The whole block diagram of the Example of the laser positioning processing method and apparatus which shows the 2nd usage example of the optical detection apparatus of FIG. The upper surface schematic of the magnet molding apparatus which shows the 3rd usage example of the optical detection apparatus of FIG. The front schematic of the magnet molding apparatus. The enlarged view of the optical sensor use part in the magnet molding apparatus.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. In addition, the same code | symbol is attached | subjected to the same or equivalent component, member, etc. which are shown by each drawing, and the overlapping description is abbreviate | omitted suitably. Further, the embodiments do not limit the invention but are exemplifications, and all features and combinations thereof described in the embodiments are not necessarily essential to the invention.

(Configuration example of optical detector)
FIG. 1 is a cross-sectional view showing a first configuration example of an optical detection device according to an embodiment of the present invention. In addition, when three directions orthogonal to each other are defined as an X direction, a Y direction, and a Z direction (the Z direction is a vertical direction), the cross section of this figure is a plane parallel to the YZ plane. The optical detection device includes a housing 191 (housing) made of aluminum or resin, and a detection unit 195. The detection unit 195 includes, for example, an imaging device such as a CCD image sensor or a CMOS image sensor and an optical system (images formed on the imaging device, such as an optical lens), or a light emitting side or a light receiving side of a photoelectric sensor. The illumination unit 197 may be incorporated together as necessary. The illumination unit 197 is, for example, fiber illumination. The detection unit 195 and the illumination unit 197 are attached so as to seal the housing 191, and the housing 191 does not allow air to enter and exit except for the opening 193 and the gas supply holes 198 and 199.

  The internal space 192 in the housing 191 and the outside of the housing 191 communicate with each other through an opening 193. The detection unit 195 has an optical axis that passes through the internal space 192 and continues from the opening 193 to the outside of the housing 191. The illumination unit 197 illuminates the outside of the housing 191 from the internal space 192 through the opening 193. The optical axis of the detection unit 195 is parallel to the Z direction, whereas the optical axis of the illumination unit 197 forms a predetermined angle with respect to the Z direction. The opening 193 preferably has a tip diameter as small as possible within the imaging range of the detection unit 195 and a range in which brightness can be secured in the imaging range. In the illustrated example, the opening 193 has a smaller diameter on the inner side (terminal side) than the lens barrel of the detection unit 195, and a smaller diameter on the outer side (tip side) than the inner diameter. In addition, the opening 193 preferably has a tapered shape with a diameter decreasing from the inner side toward the outer side.

  The gas supply holes 198 and 199 are for supplying pressurized gas (compressed air) from the compressed air source to the internal space 192. The gas is normally air, but nitrogen or argon gas may be used when an inert atmosphere is required. The gas is supplied from an air pressure supply means such as a pump or a compressor (not shown), or from a tank in which the gas is sealed at a high pressure, via a pressure adjusting device such as a regulator or a device for adjusting the flow rate. , 199 and supplied to the internal space of the housing 191. The supply gas may be standard factory air (for example, 0.2 MPa to 0.5 MPa). The gas supplied to the internal space 192 through the gas supply holes 198 and 199 is ejected from the opening 193 to the outside of the housing 191. By ejecting the gas from the opening 193, contamination of the lens of the detection unit 195 or the illumination unit 197 with cutting fluid, shavings, or a mixture thereof (hereinafter also referred to as “cutting fluid”) can be prevented. Further, the opening 193 serves as an orifice to increase the gas flow rate and blow off the cutting fluid or the like on the workpiece 10.

(First use example of optical detector)
FIG. 2 is a conceptual perspective view of a workpiece cutting apparatus showing a first usage example of the optical detection apparatus of FIG. FIG. 3 is a plan view showing an example of a workpiece 10 to be processed in this usage example. This workpiece cutting device includes a spindle unit 20, a θ table 40 as a processing table, two imaging devices 90L and 90R, and a rough positioning camera 92. The optical detection device of FIG. 1 is used as each of the two imaging devices 90L and 90R.

  The spindle unit 20 includes a flange 21, a spindle shaft / spindle bearing assembly (hereinafter referred to as “rotary shaft 22”), and a cutting rotary grindstone (hereinafter referred to as “rotating blade 23”) in which fixed abrasive grains are adhered to a base material. And a Z slider 25. The rotary blade 23 is attached to the rotary shaft 22 by a flange 21 and rotates in a plane perpendicular to the rotary shaft 22. The Z slider 25 supports the rotary shaft 22 and a drive motor (not shown) for the rotary shaft 22. The Z slider 25 is movable (slidable) in the Z direction by the support of the Y slider 70. The Y slider 70 is movable (slidable) in the Y direction by the support of a Y direction slide guide 60 (fixed to the device base (not shown)). Therefore, the rotary blade 23 is movable in the Y direction and the Z direction orthogonal to each other. In addition, the cutting fluid at the time of processing is supplied from the cutting fluid supply nozzle 30. The cutting fluid supply nozzle 30 is fixed to the spindle unit 20 and is movable in the Y direction and the Z direction integrally with the rotary blade 23.

  The imaging devices 90L and 90R are located on opposite sides of the rotation shaft 22 with respect to the X direction perpendicular to the Y direction and the Z direction. In FIG. 2, the imaging device 90 </ b> L is located on the left side of the rotation shaft 22, and the imaging device 90 </ b> R is located on the right side of the rotation shaft 22. The imaging devices 90 </ b> L and 90 </ b> R are movable in the Y direction and the Z direction similarly to the rotation shaft 22. In addition, the optical axes of the imaging devices 90L and 90R intersect the plane where the workpiece 10 exists at each position shifted by a predetermined distance from the plane perpendicular to the rotary shaft 22 passing through the mounting position of the rotary blade 23 to the same side in the Y direction. .

  The θ table 40 is supported by a θ axis 41 parallel to the Z direction. The θ axis 41 is rotated by a drive motor (not shown). The θ table 40 can rotate in the θ direction integrally with the θ axis 41. The X slider 80 is movable (slidable) in the X direction by the support of an X direction slide guide 81 (fixed to a device base (not shown)). Therefore, the workpiece 10 on the upper surface of the θ table 40, that is, the workpiece placement surface (a plane perpendicular to the Z direction) is rotatable in the XY plane and movable in the X direction.

  The Z slider 25, Y slider 70, and X slider 80 are driven by, for example, a known ball screw mechanism. The relative position of the workpiece 10 relative to the XYZ directions with respect to the rotary blade 23 and the imaging devices 90L and 90R, and the relative rotation angle about the Z direction of the workpiece 10 with respect to an arbitrary direction parallel to the XY plane (for example, the X direction) are controlled. As long as it is possible, the support structure of the workpiece 10, the rotary blade 23, and the imaging devices 90L and 90R is not limited to the above.

  A control unit 95 is stored inside the control box 5. The control unit 95 includes a processor, a memory, a program, and other elements necessary for operation control of the entire apparatus and various calculations (including image processing). The current position data of the rotary blade 23, the θ table 40, the imaging devices 90L and 90R, and other components is held in the control unit 95 in real time. The captured images of the imaging devices 90L and 90R and the coarse positioning camera 92 are stored in a memory in the control unit 95.

  The coarse positioning camera 92 captures an image including the reference mark (see FIG. 3) of the workpiece 10. Based on this image, the workpiece 10 is roughly positioned relatively before cutting. That is, based on the captured image of the coarse positioning camera 92, the control unit 95 recognizes the position of the workpiece 10, and the X-direction position and rotation angle of the θ table 40, and the Y-direction positions of the spindle unit 20 and the imaging devices 90L and 90R. Determine. Detailed positioning is performed based on an image obtained by imaging the cutting mark (see FIG. 3) of the workpiece 10 by the imaging devices 90L and 90R. One or a plurality of coarse positioning cameras 92 may be provided.

  FIG. 4 is a cross-sectional view illustrating another configuration example of the imaging devices 90L and 90R illustrated in FIG. Unlike the configuration shown in FIG. 1, there are two illumination units and one gas supply hole. The other points are the same as the configuration shown in FIG. That is, this imaging device includes a housing 291, an imaging unit 295, and illumination units 297 A and 297 B, and the housing 291 has one gas supply hole 299. The illumination units 297A and 297B are opposed to each other with the imaging unit 295 interposed therebetween, and irradiate the outside through the small diameter opening 293 with a predetermined angle with the Z direction. The housing 291 and the imaging unit 295 are supported by a cylindrical holder 280, and the holder 280 is fixed to the apparatus side by a bracket 285. This imaging apparatus also has the same operational effects as those shown in FIG. In addition, by using two illumination units, it is possible to prevent the occurrence of shadows and more reliably capture images and recognize captured images.

(Second use example of optical detector)
Here, a case where the optical detection apparatus of FIG. 1 is used in the laser positioning processing method and apparatus proposed by the present applicant in Japanese Patent Laid-Open No. 08-071780 will be described. FIG. 5 shows an overall configuration of an embodiment of a laser positioning processing method and apparatus showing a second usage example of the optical detection apparatus of FIG. In this figure, 301 is a laser oscillator that generates laser light, and 302 is a laser head (laser optical system) that receives the laser light from the laser oscillator 301 and scans it. Power is supplied to the laser oscillator 301 from a laser power source, and this laser oscillator 301 is controlled by a controller (controller) 304 to be turned on and off.

  As shown in FIG. 5, a continuous sheet-like material (for example, a continuous green sheet which is an unfired ceramic sheet) 320 as a workpiece has processing regions 320a to be laser processed at equal intervals on its upper surface. For example, image recognition marks 321 are provided at four locations so as to surround one processing region 320a. The continuous sheet 320 is repeatedly operated by an intermittent conveyance mechanism (not shown) when it is conveyed by one pitch for the arrangement interval of the processing region 320a. This one-pitch conveyance is performed with high accuracy so as not to cause a positional shift by a cylinder or a feed motor. Here, the continuous sheet 320 is disposed on the XY plane, and the conveying direction of the continuous sheet 320 coincides with the X-axis scanning direction of the laser light emitted from the laser head 302, that is, the X direction, The Y-axis scanning direction is assumed to be orthogonal to the transport direction. The four image recognition marks 321 are assumed to be at the vertices of a rectangle having two sides parallel to the X direction and two sides parallel to the Y direction.

  In FIG. 5, in order to image each of the four image recognition marks 321 in the image capturing stage Q that is one pitch before the processing stage P that performs laser processing located below the laser head 302, Four imaging cameras (CCD cameras or the like) 322 are fixedly arranged. Imaging signals (video signals) from these imaging cameras 322 are input to the image processing device 323. This image processing device 323 detects the position of each image recognition mark 321 from the image signal from each camera, and the amount of deviation from the reference arrangement of the continuous sheet 320 from the center of gravity position of the four image recognition marks 321 (X direction). Deviation amount: ΔX, deviation amount in the Y direction: ΔY, deviation amount in the rotation direction θ direction: Δθ) is detected. The controller 304 receives the output signals (ΔX, ΔY, Δθ) of the image processing device 323 and applies the scanning output signals corrected in the X direction, Y direction, and θ direction to the scanner controller 324. The scanner controller 324 adds the X-axis scanning signal and the Y-axis scanning signal to the scanner driver 325. The scanner driver 325 controls the XY galvanometer mirror system in the laser head 302 based on the X-axis scanning signal and the Y-axis scanning signal so as to cancel out the deviation amount of the continuous sheet 320 from the reference arrangement. The laser beam is positioned at a position where the scanning position of the laser beam is corrected.

  However, since laser processing “burns” the workpiece, it is inevitable that smoke-like by-products are generated from the processing region. In many cases, the laser irradiation area is surrounded for the safety of the operator, and even if an exhaust duct is prepared in the processing portion, a by-product adheres to the objective lens of the imaging camera 322.

  Therefore, the imaging camera 322 has the structure shown in FIG. 1, and contamination of the objective lens can be prevented by performing laser processing while ejecting gas from the opening 193. In this embodiment, since the recognition mark 321 exists on a plane, only one illumination may be used.

(Third use example of optical detector)
Here, a case will be described in which the optical detection device of FIG. 1 is used in order to take out material powder by a predetermined amount in the compression molding apparatus proposed by the present applicant in Japanese Patent Application Laid-Open No. 2007-083280.

  For example, when a magnet is formed using a fine and active rare earth alloy powder, it is necessary to prevent rapid oxidation of the powder, and the steps of supplying, weighing, molding and sintering the powder have a low oxygen partial pressure. It needs to be performed in a maintained nitrogen atmosphere, for example. In each of these processes, a processing unit that performs various types of processing inside each dedicated device or actually performs various processes is surrounded by a housing, etc., and the oxygen partial pressure of the gas inside the housing is managed, and more simply nitrogen replacement. It is considered possible to satisfy these needs.

  FIG. 6 shows a schematic top view of a magnet molding apparatus showing a third usage example of the optical detection apparatus of FIG. FIG. 7 shows a schematic front view of the magnet molding apparatus. FIG. 8 is an enlarged view of a portion where the photoelectric sensor is used in the magnet molding apparatus. The magnetic powder molding apparatus 400 is disposed between the material supply unit 410, the weighing unit 420, the filling / magnetic field press molding unit 430, the alignment unit 440, the transport zone 450, and the filling / magnetic field press molding unit 430 and the alignment unit 440. Maintenance zone 460. Each of these parts is configured by arranging a predetermined unit in a casing isolated from the external atmosphere.

  The material powder mainly composed of rare earth alloy powder is brought into the material supply unit 410 by a capsule 402 capable of holding the material powder in a nitrogen atmosphere. The capsule 402 set in the supply elevator 412 of the material supply unit 410 is conveyed by the elevator, and the material powder is taken out by the photoelectric sensor 495 at a predetermined position by a predetermined amount. The material powder taken out by a predetermined amount is made a predetermined amount by a more precise weighing in the weighing unit 421 in the weighing unit 420 and then filled in a predetermined portion of the compression molding unit such as a molding die.

  The material powder is further conveyed to the magnetic field press molding unit 430, and compression molded with a magnetic field applied in an arbitrary direction in the molding unit 430 to obtain a molded body before sintering treatment having a predetermined shape and strength. The molded body is taken out from the filling / magnetic field press molding unit 430 by the take-out robot 442 and placed on the tray 413 arranged in the alignment unit 440. Here, the take-out robot 442 has an arm length that can hold the molded magnetic powder (hereinafter referred to as a molded body) present in the filling / magnetic field press molding unit 430 via the maintenance zone 460. Yes. When a predetermined number of molded bodies are placed on the tray 413, the tray 413 is transported toward the opening 450 a in the transport zone 450 by the processing device conveyor disposed so as to be continuous in the transport zone 450. The The tray 413 taken out from the opening 450a is transported to another apparatus by the automatic guided vehicle 481.

  In the magnetic powder molding apparatus 400, the photoelectric sensor 495 has a role of checking the approximate amount of the powder material falling in the material supply unit. However, as described above, the powder is isolated from the external atmosphere to prevent oxidation. For example, there is an idea of providing a light emitting window in the material supply unit 410 and attaching a light projecting unit and a light receiving unit of a photoelectric sensor outside the window, but the window is immediately contaminated due to the powder material.

  Therefore, as shown in an enlarged view in FIG. 8, a housing 491 communicating with the material supply unit 410, a pair of photoelectric sensors 495 (light emitting side and light receiving side) attached so as to substantially seal one end of the housing 491, Adopting a photoelectric sensor unit having a nitrogen supply means for supplying nitrogen at a predetermined pressure to the remaining space in the housing 491 (the light emitting side and the light receiving side are equivalent to those excluding the illumination unit 197 from FIG. 1). Thus, the approximate amount of the powder material can be checked without the objective lens of the photoelectric sensor 495 being contaminated by dust produced by the powder material and without impairing the nitrogen atmosphere.

(Effects of embodiment, industrial applicability)
As seen in the above three examples, the optical detection device of the present embodiment is
The gas supplied to the internal space is ejected from the opening that also serves as the orifice to the outside of the housing at a high flow rate. By ejecting the gas from the opening, the gas is caused by cutting fluid, shavings or a mixture thereof (hereinafter referred to as contaminants) and dust. Contamination of the objective lens or illumination unit of the imaging or optical detection unit can be prevented before adhering dust,
If the cause of contamination is contaminants (liquid, slurry, etc.), increase the pressure supplied to the internal space and make the opening communicating with the outside as small as possible, so that contaminants can enter the housing internal space from the opening. Surely prevent,
If the cause of contamination is dust, reducing the pressure supplied to the internal space reduces wasteful gas consumption,
Further, when the detection target is powder, the detection target can be adjusted to a predetermined gas pressure that is not disturbed by the gas ejected from the opening and prevents dust from entering the internal space of the housing.
Therefore, it is desirable to provide a gas pressure adjusting means (regulator) in the path for supplying gas to the internal space. Furthermore, when it is desired to suppress unnecessary consumption of gas, it is preferable to provide a shut-off valve in a path for supplying gas to the internal space. It is desirable to use an electrically controllable valve such as an electromagnetic valve so that the shutoff valve can be opened and closed in conjunction with the operation of the apparatus.

  The present invention has been described above by taking the embodiment as an example, but it will be understood by those skilled in the art that various components and processing processes of the embodiment can be variously modified within the scope of the claims. By the way.

191 Housing 192 Internal space 193 Opening 195 Detection unit 197 Illumination unit 198,199 Gas supply hole

Claims (6)

A housing;
An internal space in the housing;
An opening that allows communication between the outside of the housing and the internal space;
A detection unit having an optical axis passing through the internal space and continuing from the opening to the outside of the housing;
A gas supply hole for supplying gas to the internal space,
The optical detection device having a configuration in which the gas supplied to the internal space through the gas supply hole is ejected from the opening to the outside of the housing.   The optical detection apparatus according to claim 1, further comprising an adjusting unit for adjusting a pressure of the gas to be delivered to the gas supply hole.   The optical detection device according to claim 1, wherein the optical detection device includes an imaging element and an optical system in a lens barrel.   The optical detection device according to claim 1, further comprising an illumination unit that illuminates the outside of the housing through the opening from the internal space. A housing;
An internal space in the housing;
An opening that allows communication between the outside of the housing and the internal space;
An imaging unit including an imaging element and an optical lens having an imaging optical axis that passes through the internal space and extends from the opening to the outside of the housing;
An illumination unit that illuminates the exterior of the housing through the opening from the internal space;
A gas supply hole for supplying gas to the internal space;
And means for adjusting the pressure of the gas delivered to the gas supply hole,
The optical detection device having a configuration in which the gas supplied to the internal space through the gas supply hole is ejected from the opening to the outside of the housing.   The optical detection device according to claim 1, wherein the opening serves also as an orifice and ejects the gas in the internal space at a high flow velocity.

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