JP2014149175A - Optical measuring device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical measuring device achieving reduction in space and costs.SOLUTION: Light from a measuring lamp 61 with which a measuring instrument 22 is provided is transmitted by a half mirror 63 to a coaxial epi-illumination telecentric lens 71, and the coaxial epi-illumination telecentric lens 71 emits the light as parallel light 72 to an object 2. The parallel light 72 reaches a mirror 12 while a part of the parallel light 72 is blocked by the object 2, which provides a shadow of the object 2 on the mirror 12. Light reflected by the mirror 12 passes through the coaxial epi-illumination telecentric lens 71, the half mirror 63, an imaging lens 65, and then an image of the light is taken by the camera 42. A control section 81 analyzes the image. Measuring external diameter dimensions, etc. of various parts of the object 2 on the basis of a shadow image 101 of the object 2 achieves inspection.

Description

  The present invention relates to an optical measuring device that measures an outer diameter of an object.

  Conventionally, when measuring the dimensions of a processed part, an optical measuring device has been used (for example, Patent Document 1), and the optical measuring device shown in FIG.

  The optical measuring device 801 includes a light transmitting unit 803 that transmits light to the object 802 and a light receiving unit 804 that receives light from the light transmitting unit 803.

  The translucent portion 803 includes an LED 811 as illumination and an irradiation side optical system 812 for irradiating light from the LED 811. The irradiation side optical system 812 includes a diffusion unit 813 that diffuses the light from the LED 811, a lens 814 that allows the light diffused by the diffusion unit 813 to pass, and a light transmission side mirror that reflects the light from the lens 814. 815 and a translucent lens 817 that converts the light from the translucent mirror 815 into parallel light 816, and a telecentric optical system that projects the parallel light 816 onto the object 802. .

  The light receiving unit 804 includes a light receiving side optical system 821 and an image pickup unit 822. The light receiving side optical system 821 receives a light receiving lens through which the parallel light 816 projected through the object 802 passes. 823, a light receiving side mirror 824 that reflects light from the light receiving lens 823, and a light receiving side lens 825 that reflects by the light receiving side mirror 824 and passes light. The imaging means 822 is composed of a CMOS 826 that receives light that has passed through the light-receiving side lens 825, so that parallel light 816 that is partially blocked by the object 802 is displayed on the CMOS 826. It is configured.

  Thereby, it is comprised so that the outer diameter dimension etc. of the target object 802 can be measured by measuring the shadow image of the said target object.

JP 2011-232336 A

  However, in such an optical measuring device 801, both the irradiation side optical system 812 and the light receiving side optical system 821 must be provided, and there is a problem that a space is required and a cost is increased. .

  The present invention has been made in view of such a conventional problem, and an object of the present invention is to provide an optical measurement apparatus capable of saving space and reducing costs.

  In order to solve the above-mentioned problem, in the optical measuring device according to claim 1 of the present invention, in an optical measuring device that performs measurement by irradiating light on an object, light from illumination is directed to one side through a half mirror. Epi-illumination that irradiates and projects the image on the one side to the other side via the half mirror, and telecentric optics that irradiates the object with parallel light from the epi-illumination. An epi-illumination telecentric optical system provided with a system, a reflecting means provided on the one side from the object, and reflecting the light from the epi-illumination telecentric optical system to the epi-illumination telecentric optical system side; and Imaging means for capturing an image projected to the other side via the epi-illumination telecentric optical system.

  That is, the light from the illumination is irradiated to one side through the half mirror, and then converted into parallel light by the telecentric optical system to irradiate the object.

  The parallel light that has passed through the object is reflected toward the epi-illumination telecentric optical system by the reflecting means provided on the one side from the object, and an image by this reflection, that is, an image reflected on the reflecting means is Then, the light passes through the half mirror constituting the epi-illumination and is projected to the other side and imaged by the imaging means.

  As a result, the imaging unit can acquire a shadow image of the object, and thus can measure the outer diameter of the object.

  Thus, the outer diameter dimension of the object is measured only by the telecentric optical system.

  The optical measuring device according to claim 2 further includes an illumination for visual inspection that irradiates the object with illumination for visual inspection.

  That is, since the optical measurement apparatus includes the appearance inspection illumination for irradiating the object with the illumination for appearance inspection, when the image reflected by the reflection means is captured by the imaging means, The state of the surface of the object can also be inspected.

  Examples of the inspection method include known light cutting methods, pattern projection methods, and pattern reflection methods, and the three-dimensional shape of the object surface can be obtained by these methods.

  Furthermore, in the optical measuring device according to claim 3, color map display means for comparing the shape measurement data of the master serving as a reference with the object to be inspected and displaying the state of the appearance shape of the object to be inspected as a color map. It has more.

  That is, when acquiring a color map of an object to be inspected, external shape measurement data in a master serving as a reference is acquired in advance. And the measurement data of the external shape of the target object to be inspected are acquired, and both measurement data are compared.

  When there is a difference between the two measurement data, for example, when a predetermined portion of the object to be inspected with respect to the master protrudes, the portion is red. Further, when a predetermined portion of the object to be inspected with respect to the master is recessed, the portion is blue, and these red and blue colors are displayed on the display screen of the object.

  Thereby, the state of the appearance shape of the inspection object is displayed as a color map.

  In the optical measurement device according to the fourth aspect, the end portion of the object is detected using the image acquired by the imaging means.

  That is, in the imaging unit, the shape of the object is acquired, and the end portion of the object is detected by using the image acquired by the imaging unit.

  For this reason, when an object with a long length is measured while moving the epi-illumination telecentric optical system in the length direction, the measurement end point position is acquired.

  As described above, in the optical measuring device according to the first aspect of the present invention, the outer diameter and the like of the object can be measured only by the telecentric optical system of the epi-illumination telecentric optical system.

  For this reason, if both the irradiation side optical system and the light receiving side optical system are not provided, the space can be saved and the cost can be reduced as compared with the conventional case in which the outer diameter dimension or the like cannot be measured. Can be achieved.

  Further, in the optical measuring device according to the second aspect of the present invention, by providing the appearance inspection illumination for irradiating the object with the illumination for appearance inspection, the image reflected by the reflection means is captured by the imaging means, and the outer diameter size and the like are determined. Simultaneously with the measurement, the state of the surface of the object can also be inspected.

  Furthermore, in the optical measuring device according to the third aspect, the state of the appearance shape of the inspection object can be displayed as a color map.

  This makes it possible to easily determine whether the inspection object is good or bad.

  Further, in the optical measuring device according to claim 4, a separate sensor is provided when measuring the epi-illumination telecentric optical system while moving in the length direction when measuring an object having a long length. The measurement end point position can be acquired without any problem.

  Thereby, cost reduction can be achieved.

It is explanatory drawing which shows 1st embodiment of this invention, (a) is a top view, (b) is a side view. It is explanatory drawing which shows the structure of the optical measuring device of the embodiment. (A) is an image acquired in the embodiment, and (b) is an explanatory diagram showing a color map. It is a flowchart which shows the operation | movement of the embodiment. It is explanatory drawing which shows a prior art example.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

  FIG. 1 is an explanatory view showing an optical measuring apparatus 1 according to the present embodiment. The optical measuring apparatus 1 is an apparatus for inspecting an object 2 such as a spool valve by applying light.

  This optical measuring device 1 includes a flat stage 11, and a mirror 12 as a reflecting means is provided on the upper surface of the stage 11. A support column 13 is erected on one end side of the stage 11, and a slide rail 14 extending along the mirror 12 is provided on the support column 13 in parallel with the mirror 12. Yes.

  A slider 21 is slidably supported on the slide rail 14, and the slider 21 can be moved along the slide rail 14 by a stepping motor (not shown). A measuring instrument 22 is supported on the slider 21, and the measuring instrument 22 is supported so as to be movable along the slide rail 14.

  On the lower side 31 that is one side of the measuring instrument 22, a holding mechanism 32 that holds the object 2 while being sandwiched from both ends in the length direction is provided. The holding mechanism 32 includes a motor 33, a fixing portion 34 provided on the rotation shaft of the motor 33, and a chuck 35 provided so as to face the fixing portion 34, and the fixing portion 34 and the chuck 35 are provided. The opposite part is formed in a tapered conical shape.

  The chuck 35 is configured to be movable in the length direction thereof, and the chuck 35 is moved toward the fixing portion 34 in a state in which one end of the object 2 is aligned with the fixing portion 34. The object 2 is configured to be held in a state of being sandwiched by the fixing portion 34 and the chuck 35 from both ends in the length direction.

  The mirror 12 is disposed on the lower side 31 that is one side of the holding mechanism 32.

  FIG. 2 is an explanatory view showing the structure of the optical measuring device 1, and the measuring instrument 22 of the optical measuring device 1 is composed of an epi-illumination telecentric optical system 41 and a camera 42.

  The epi-illumination telecentric optical system 41 includes an epi-illumination 51 and a telecentric optical system 52.

  The epi-illumination 51 includes a measurement illumination 61, an illumination-side lens 62 through which the light from the measurement illumination 61 passes, and a half that reflects and emits the light from the illumination-side lens 62 toward the lower side 31. A mirror 63 and an imaging lens 65 provided on the upper side 64 that is the other side of the half mirror 63 are provided, and an image on the lower side 31 of the half mirror 63 is converted into the half mirror 63 and the imaging lens 65. It is comprised so that it can project to the upper side 64 which is the other side.

  The telecentric optical system 52 includes a coaxial epi-illumination telecentric lens 71 that irradiates light from the half mirror 63 toward the lower side 31 that is one side. The light from the mirror 63 is configured to irradiate the lower side 31 as parallel light 72.

  The holding mechanism 32 is provided on the lower side 31 of the epi-illumination telecentric optical system 41, and light from the epi-illumination telecentric optical system 41 is applied to the lower side 31 of the holding mechanism 32. The mirror 12 is provided as a reflecting means for reflecting toward the telecentric optical system 41 side.

  On the upper part of the imaging lens 65 provided in the epi-illumination telecentric optical system 41, as an imaging means for imaging an image projected from the mirror 12 to the upper side 64 via the epi-illumination telecentric optical system 41. The camera 42 is provided, and the camera 42 is configured to output a captured image to the control unit 81.

  The control unit 81 is configured to control the stepping motor so that the measuring instrument 22 can be moved along the length direction of the object 2 held by the holding mechanism 32. By controlling 33, the object 2 held by the holding mechanism 32 can be rotated about its axis.

  Thereby, while measuring the said target object 2 hold | maintained of the said holding mechanism 32 over the whole length direction, it is comprised so that the whole peripheral surface area of the said target object 2 can be test | inspected.

  The measuring instrument 22 includes an appearance inspection illumination 91 that is held by the holding mechanism 32 to irradiate the object 2 with illumination for appearance inspection, and the appearance inspection illumination 91 applies slit light to the object. The object 2 can be irradiated from an oblique direction.

  In this Embodiment concerning the above structure, when inspecting the target object 2, the target object 2 is set in the holding mechanism 32.

  And the said measuring device 22 is moved to the length direction of the said target object 2 by controlling the said stepping motor, and the said target object 2 hold | maintained of the said holding mechanism 32 is measured over the whole length direction. . Further, the entire peripheral surface of the object 2 is inspected by rotating the object 2 by controlling the motor 33.

  That is, the light of the measurement illumination 61 provided in the measuring instrument 22 is sent to the coaxial epi-illumination telecentric lens 71 through the half mirror 63, and converted into parallel light 72 by the coaxial epi-illumination telecentric lens 71. Irradiation toward the object 2.

  At this time, a part of the parallel light 72 reaches the mirror 12 while being blocked by the object 2. As a result, the shadow of the object 2 is reflected on the mirror 12.

  The reflected light reflected on the upper side 64 by the mirror 12 is picked up by the camera 42 via the coaxial epi-illumination telecentric lens 71, the half mirror 63 and the imaging lens 65, and the picked-up image is sent to the control unit 81. Sent.

  As shown in FIG. 3A, the control unit 81 analyzes the shadow image 101 of the object 2 from the captured image, and the outer diameter dimensions of various portions of the object 2 from the shadow image 101. Etc. are measured and inspected.

  Thus, the outer diameter dimension of the object 2 can be measured only by the telecentric optical system 52.

  For this reason, unless both the irradiation side optical system and the light receiving side optical system are provided, the optical system is installed only on the upper side of the object 2 as compared with the conventional case in which the outer diameter dimension and the like cannot be measured. Therefore, space saving and cost reduction can be achieved.

  Further, since the outer diameter of the object 2 can be measured only by the telecentric optical system 52, the movable part can be reduced in size and weight. Thereby, the movable part can be moved at high speed, and the measurement time can be shortened.

  Furthermore, since the outer diameter of the object 2 can be measured only by installing the telecentric optical system 52 on one side of the object 2, it is easy to secure a space for attaching and detaching the object 2.

  At this time, the object 2 is irradiated with the slit light 111 from the appearance inspection illumination 91, and the slit light 111,... Is projected on a part of the shadow image 101. For this reason, the three-dimensional shape of the surface of the object 2 can be obtained by using a known light cutting method, pattern projection method, or pattern reflection method. It is also possible to acquire a three-dimensional shape from point cloud data.

  As a result, the image reflected by the mirror 12 is picked up by the camera 42 and the outer diameter and the like are measured, and at the same time, the uneven state of the surface of the object 2 can be inspected.

  FIG. 3B is a diagram showing the color map 121 displayed on the monitor connected to the control unit 81. When obtaining the color map 121 of the object 2 to be inspected, FIG. In this way, the measurement data indicating the external shape of the master serving as a reference, that is, the reference position on the surface of the master, is acquired and stored (S1).

  And the external appearance shape of the target object 2 to be inspected is measured to obtain measurement data (S2), and is compared with the master measurement data (S3).

  When there is a difference between the two measurement data, for example, when a predetermined part of the object 2 to be inspected with respect to the master protrudes, the part is red. In addition, when a predetermined portion of the object 2 to be inspected with respect to the master is recessed, the portion is blue, and these red and blue are displayed as a red portion 131 and a blue portion 132. It is displayed on 133 (S4).

  Thereby, the state of the external shape of the object 2 to be inspected is displayed on the monitor as a color map 121 as shown in FIG. 3B, so that it is easy to judge whether the object 2 to be inspected is good or bad. Can do.

  On the other hand, the control unit 81 controls the stepping motor to move the measuring instrument 22 in the length direction of the target object 2, so that the length of the target object 2 held by the holding mechanism 32 is increased. Measure across the entire direction.

  At this time, the camera 42 acquires the shape of the shadow of the object 2, and the end portion of the object can be detected by using the image acquired by the camera 42.

  More specifically, as shown in FIG. 3A, the contact point 142 between the shadow image 101 of the object 2 and the shadow image 141 of the chuck 35 is determined as the end of the object 2. it can.

  For this reason, when measuring the measuring instrument 22 while moving in the length direction when measuring the object 2 having a long length as in the present embodiment, the end of the object 2 is The measurement end point position can be acquired without separately providing a sensor for detection.

  Thereby, cost reduction can be achieved.

DESCRIPTION OF SYMBOLS 1 Optical measuring apparatus 2 Object 12 Mirror 31 Lower side 41 Epi-illumination telecentric optical system 42 Camera 51 Epi-illumination 52 Tele-centric optical system 61 Measurement illumination 63 Half mirror 64 Upper part 71 Coaxial epi-illumination telecentric lens 72 Parallel light 81 Control part 91 Appearance Inspection lighting 121 Color map

Claims (4)

In an optical measurement device that measures light by shining on an object,
Epi-illumination that irradiates light from the illumination to one side via a half mirror and projects an image on the one side to the other side via the half mirror, and illumination from the epi-illumination toward the one side An epi-illumination telecentric optical system including a telecentric optical system that irradiates the object with parallel light.
Reflecting means that is provided on the one side from the object and reflects light from the epi-illumination telecentric optical system to the epi-illumination telecentric optical system side;
Imaging means for capturing an image projected from the reflecting means to the other side via the epi-illumination telecentric optical system;
An optical measuring device comprising:   The optical measurement apparatus according to claim 1, further comprising an illumination for visual inspection that irradiates the object with illumination for visual inspection.   3. A color map display means for comparing the shape measurement data of the reference master with the object to be inspected and displaying the state of the appearance shape of the object to be inspected as a color map. The optical measuring device described.   The optical measurement apparatus according to claim 1, wherein an end portion of the object is detected using an image acquired by the imaging unit.

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