JP4443284B2 - Light source holding device set - Google Patents

Description

  The present invention relates to a light source holding device which is a constituent member of a light irradiation device used for detecting defects on a surface of a product or the like (hereinafter referred to as a workpiece) or for mark recognition.

  Conventionally, various illumination devices (light irradiation devices) for inspecting a workpiece surface and the like have been developed. For example, as shown in Patent Document 1, a ring-type light irradiation device that emits low-angle light from the surroundings, Various types according to the form of the workpiece and its irradiation purpose are known, such as a line-type light irradiation device configured to irradiate the workpiece with line light in combination with this.

Such a light irradiation apparatus includes a light source body that emits light and a light source holding device that holds the light source body. The light source holding device is provided with an observation hole, and a workpiece is imaged by the imaging device through the observation hole, and an inspection is performed by performing image processing.
Japanese Patent Laid-Open No. 10-21729

  However, the light irradiation device described above is basically one aspect of one product, for example, illumination that emits light from the same direction as the observation axis (hereinafter referred to as coaxial illumination, such light is referred to as coaxial light). Two types of light source holding devices are required depending on whether the light source is required or not. As a result, substantially two types of light irradiation devices themselves must be prepared. Also, for example, if you have an observation lens for setting the magnification of the image, prepare different types of light source holding devices for each lens holding tube length to vary the magnification. Will have to do.

  For this reason, in the conventional configuration, if the functions and configurations are slightly different, a different type of light irradiation device must be prepared for each, resulting in an extremely large variety of products and a small production lot. In addition, there is a risk of incurring a cost increase due to labor and manufacturing.

  In addition, it is necessary to consider the location of the light source body. For example, if the light source body is arranged on the front end side (target area side), it may cause wrinkles in the installation of other parts such as the second light source body for oblique illumination, and it is necessary to consider the arrangement location thereof. is there.

  The present invention has been made to solve such problems all at once, and by dividing the light source holding device into a plurality of replaceable units among the components constituting this type of light irradiation device, it is possible to make the components possible. The main challenge is to achieve various functions by simply exchanging some units while minimizing cost increase by standardization.

  In addition, in the case of multiple units, if the arrangement of each part is not taken into consideration, the work and structure may be hindered when replacing or adding parts. At the same time, a light source holding device is arranged on the device side so that other components such as a second light source body for oblique illumination can be easily attached and replaced.

  That is, the light source holding device according to the present invention is used for surface inspection of products and the like, has an observation hole for imaging a target area of the product or the like with an imaging device, and holds a light source body that emits light to the target area A coupling tube coupled to the imaging device, a lens holding tip tube that holds the observation lens and faces the target area, and between the coupling tube and the lens holding tip tube A light source holding intermediate tube that holds a light source body that emits light that emits light whose traveling direction coincides with the observation axis, and at least the light source holding intermediate tube is arranged with its axis aligned with the observation axis It is characterized in that it is configured to be selectively replaceable with a straight straight intermediate tube. Here, “surface inspection” refers to surface defect detection and mark recognition. In addition, “light whose traveling direction matches the observation axis” refers to the coaxial light, and includes not only parallel light but also light that travels while diffusing with the observation axis coincident with the optical axis and diffused light.

  If this is the case, it is sufficient to replace at least the intermediate tube with the light source holding one and the straight type with the case where the coaxial light is required and the case where the coaxial light is not required. The standardization of parts can be promoted as much as possible, and the cost increase can be minimized.

  Also, since the lens holding tip tube is arranged closer to the target area than the light source holding intermediate tube, the tip tube can be replaced with one of a different length to change the magnification, or the tip tube can be used for oblique illumination. It is possible to easily attach other parts such as attaching the second light source body.

  In addition, since the observation lens also serves to collect the coaxial light, it is possible to irradiate the target area with a sufficient amount of light.

  As a specific embodiment of the intermediate tube for holding a light source, the intermediate tube for holding a light source has a cylindrical main body arranged with its axis aligned with the observation axis, and a side through a side hole provided in the main body. A light source holder that holds a light source body that emits light from one side, and a half that is disposed obliquely on the observation axis of the main body, reflects light emitted from the light source body, and travels toward the target area along the observation axis The thing provided with the mirror can be mentioned.

  In order to further promote both standardization and multi-functionalization of parts, it is desirable that the main body detachably holds at least one of the diffusion plate and the light collimating lens between the light source body and the half mirror. . If this is the case, the three light source modes can be selected when the diffuser plate is used, when the light collimating lens is used, and when both are arranged in series along the optical axis. While being used, it is possible to select and irradiate one coaxial light according to the inspection purpose from a plurality of types of coaxial light.

  To change the magnification of the image in the target area, it is conceivable to prepare multiple types of lens holding tip tubes with different lengths as described above, but this is from the viewpoint of promoting cost reduction by standardizing parts. For example, it is preferable to further include a cylindrical distance changing tube that is configured to be selectively attached between the lens holding tip tube and the intermediate tube.

  In order to increase the depth of field, it is preferable that the lens holding tip tube hold the diaphragm detachably on the target area side than the observation lens.

  For example, by performing oblique illumination from around the target area and detecting defects by highlighting defects white in the dark field, it is possible to irradiate the target area with light in addition to the coaxial light so that more diverse light irradiation can be performed. In order to achieve this, it is preferable that the second light source body that irradiates the target area with light from around can be attached.

  According to the present invention configured as described above, various functions can be exhibited by simply exchanging, adding, or deleting a part while minimizing cost increase by standardizing parts as much as possible. A light source holding device that can irradiate a target area with a sufficient amount of light can be provided.

  An embodiment of the present invention will be described below with reference to the drawings.

  The light source holding device 1 according to the present embodiment is a component of a light irradiation device used for surface inspection of a workpiece, and an observation hole H that is penetrated along an observation axis C in order to image a target area AR of the workpiece. And a light source body LD1 for irradiating the target area AR with light.

  Specifically, as shown in FIG. 1, an annular coupling tube 2 connected to an imaging device (for example, a CCD camera or a CMOS camera, not shown) for imaging the target area AR, and an observation A lens holding tip tube 3 that holds the lens 31 and faces the target area AR, and a light source holding intermediate tube 4 interposed between the coupling tube 2 and the lens holding tip tube 3. They are configured to be separated and replaceable.

  Each part will be described in detail.

  The coupling tube 2 has an annular shape, and has a male screw portion 21 formed on the outer peripheral surface of the base end portion thereof, and is detachably attached to the body of the imaging apparatus using the male screw portion 21. Further, the proximal end portion of the light source holding intermediate tube 4 is fitted and attached to the inner peripheral surface of the distal end portion. For fixing, for example, a set screw penetrated in the radial direction is used. ing.

  The light source holding intermediate tube 4 includes a cylindrical main body 41 that is arranged with its axis aligned with the observation axis C, and a light source holder 42 attached to the side surface of the main body 41.

  As described above, the main body 41 is removably attached to the coupling pipe 2 by fitting its outer peripheral surface to the inner peripheral surface of the coupling pipe 2 as described above. A female thread portion 43 for attaching the lens holding tip tube 3 is formed. Further, a half mirror 5 attached at an angle of 45 ° is fixed on the center axis (observation axis C) inside the main body 41, and a side hole 44 penetrating in the radial direction on the side of the half mirror 5. Is provided.

  The light source holder 42 has a cylindrical shape for holding a light source body LD1 for coaxial illumination using LEDs, and the axis C1 is aligned with the side hole 44 of the main body 41, that is, so as to be orthogonal to the main body 41. The main body 41 is detachably attached to the side surface using screws or the like. The light source holder 42 is provided with, for example, a step 45 on the inner periphery of the tip, thereby forming a diffusion plate attachment portion and a lens attachment portion for attaching the diffusion plate 6 and the light collimating lens 7. Then, it is possible to select three modes in which both the diffusion plate 6 and the light collimating lens 7 are attached in series along the axis C1, or any one of them is attached, or none of them is attached.

  The lens holding tip tube 3 has a cylindrical shape having the same diameter as the main body 41, and holds a plurality (three in this case) of observation lenses 31 in series on the central axis (observation axis C). Therefore, the external thread portion 32 provided on the outer periphery of the base end portion is detachably attached to the main body 41 by being screwed to the screw portion 43 for providing at the distal end portion of the main body 41. More specifically, a large-diameter portion is provided on the inner peripheral surface of the lens holding tip tube 3, and the plurality of lenses 31 can be fitted into the large-diameter portion. An annular spacer 33 is interposed between the lenses 31 so that they are separated from each other by a predetermined distance. In addition, the lens 31 is fixed by attaching a pressing ring 34 from the tip to the plurality of lenses 31 that are fitted. Further, the diaphragm plate 8 can be fitted between the pressing ring 34 and the lens 31 with an annular spacer 33 interposed therebetween in order to increase the depth of field.

  In this embodiment, however, the light source holding intermediate tube 4 is configured to be replaceable with a straight intermediate tube 4A as shown in FIG. More specifically, the straight type intermediate tube 4A is a cylindrical tube having the same length and the same diameter as the main body 41 of the light source holding intermediate tube 4, and is attached to the coupling tube 2 provided at the base end thereof. In addition, the mounting structure for the lens holding tip tube 3 provided at the tip portion is made common with the light source holding intermediate tube 4. In this way, the straight type intermediate tube 4A is replaced with the light source holding intermediate tube 4 so that the central axis thereof can be aligned with the observation axis C.

  In this embodiment, as shown in FIGS. 3 to 6, a distance changing tube 9 is interposed between the intermediate tubes 4, 4 </ b> A and the lens holding tip tube 3. This distance changing pipe 9 has a cylindrical shape with the same diameter as the intermediate pipes 4 and 4A, and has a threaded portion 91 for attaching to the distal end of the intermediate pipes 4 and 4A. A female threaded portion 92 is formed at the distal end of the lens holding distal end tube 3 for attachment to the proximal end. In this example, two types of lengths are prepared for the distance changing tube 9, and when the long type 9 (a) is mounted (see FIGS. 3 and 4), the magnification is double and the type is short. When 9 (b) is mounted (see FIGS. 5 and 6), the magnification is set to the same magnification, and when not mounted (see FIGS. 1 and 2), the magnification is set to be 0.5 times. .

  According to the light source holding device 1 according to the present embodiment configured as described above, only the intermediate tube is used for holding the light source 4 and the straight type 4A for cases where the coaxial light is required and not required. Therefore, other parts can be used in common, and the standardization of the parts can be promoted as much as possible to minimize the cost increase.

  Further, since the lens holding tip tube 3 is arranged on the target area AR side with respect to the light source holding intermediate tube 4, the light source holding intermediate tube 4 does not interfere with the tip tube 3, for example as shown in FIG. As described above, it is possible to easily mount other components such as attaching the second light source body LD2 for oblique illumination.

  Furthermore, since the observation lens 31 also serves to collect the coaxial light, it is possible to irradiate the target area AR with a sufficient amount of light.

  In addition, since the main body 41 detachably holds at least one of the diffusion plate 6 and the light collimating lens 7 between the light source body LD1 and the half mirror 5, as described above, only the diffusion plate 6 is provided. Can be selected, and only the lens 7 for light collimation is used, and when both are arranged in series along the optical axis, a plurality of types of coaxials can be selected while using the same light source LD1. It is possible to select and irradiate one coaxial light according to the inspection purpose from the light.

  In addition, since the distance changing tube 9 can be selectively attached between the lens holding tip tube 3 and the intermediate tube, the lens holding tip tube 3 can also be standardized.

  The present invention is not limited to the above embodiment.

  For example, oblique illumination is performed from around the target area AR, and defects are detected by highlighting the defects white in the dark field. In addition to the coaxial light, the target area AR is irradiated with light to further irradiate various types of light. In order to be able to do so, as shown in FIG. 7, it is preferable that the second light source body LD2 that irradiates the target area AR with light from the surroundings can be attached. In this figure, the second light source body LD2 includes a light emitting source LD21 using an LED, an optical fiber LD22, a head LD23, and a bracket LD24. The light source LD21 is attached to the distance changing tube 9 via the bracket LD24. The light emitted from the light source LD21 is guided to a head LD23 attached to the peripheral tip of the lens holding tip tube 3 through a plurality of optical fibers LD22, and low angle light is emitted from the head LD23. Of course, it goes without saying that the second light source body is not limited to this.

  Of course, a plurality of types of intermediate tubes and lens holding tip tubes having different light source bodies can be prepared and configured to be exchangeable. The distance changing tube may be a telescopic type so that the magnification can be freely changed.

  In addition, the present invention is not limited to the above embodiment, and various modifications can be made without departing from the spirit of the present invention.

The longitudinal cross-sectional view which shows the example of 1 aspect of the light source holding device in one Embodiment of this invention. The longitudinal cross-sectional view which shows the other example of a light source holding device in the embodiment. The longitudinal cross-sectional view which shows the further another example of a light source holding | maintenance apparatus in the embodiment. The longitudinal cross-sectional view which shows the further another example of a light source holding | maintenance apparatus in the embodiment. The longitudinal cross-sectional view which shows the further another example of a light source holding | maintenance apparatus in the embodiment. The longitudinal cross-sectional view which shows the further another example of a light source holding | maintenance apparatus in the embodiment. The longitudinal cross-sectional view which shows the light source holding | maintenance apparatus in other embodiment of this invention.

Explanation of symbols

AR ... Target area H ... Observation hole LD1 ... Light source C ... Observation axis 2 ... Coupling tube 3 ... Lens holding tip tube 31 ... Observation lens 4 ... Light source holding intermediate tube 4A ... straight type intermediate tube 41 ... main body 42 ... light source holder 44 ... side hole 5 ... half mirror 6 ... diffuser plate 7 ... light collimating lens 8 ... Aperture (aperture plate)
9 ... Distance change tube LD2 ... Second light source

Claims (6)

It is used for surface inspection of products, etc., and has an observation hole for imaging a target area such as the product with an imaging device and can hold a light source that irradiates light to the target area,
A coupling tube coupled to the imaging device; a lens holding tip tube that holds the observation lens and faces the target area; and is interposed between the coupling tube and the lens holding tip tube; A light source holding device comprising: a light source holding intermediate tube that holds a light source body that emits light whose traveling direction matches; and a cylindrical straight intermediate tube that is replaceable with the light source holding intermediate tube. Equipment set . The light source holding intermediate tube includes a cylindrical main body arranged with its axis aligned with the observation axis, and a light source holder attached to a side surface of the main body, and a light source body held by the light source holder Then, the light irradiated inside the main body through the side hole provided in the main body is reflected by a half mirror arranged obliquely on the observation axis of the main body, and proceeds toward the target area along the observation axis. The light source holding device set according to claim 1, which is configured as follows. The light source holding device set according to claim 2, wherein the main body detachably holds at least one of the diffusion plate and the light collimating lens between the light source body and the half mirror. 4. A light source holding device according to claim 1, further comprising a distance changing tube having a cylindrical shape, wherein the distance changing tube can be selectively attached between the lens holding tip tube and the intermediate tube. Equipment set . The light source holding device set according to claim 1, 2, 3, or 4, wherein the lens holding tip tube detachably holds the stop closer to the target area than the observation lens. The light source holding device set according to claim 1, 2, 3, 4, or 5, wherein the second light source body that irradiates light from the periphery to the target area can be attached.