JPH1163930A - Lighting system for image measuring instrument - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a low-priced lighting system for an image measuring instrument, which prevents erroneous edge position detection due to scratches or coating on an object to be measured without increasing the quantity of light for illumination, and irradiates illumination light effectively to the object to be measured by suppressing an influence of external disturbance light. SOLUTION: This lighting system is provided with a ring light 46 for irradiating scattered light, and three types of color filters 42 of red, blue, and green with gradation, which are formed so as to be slid freely at the front surface of a camera, and can have difficulty in looking at scratches or coating of every color by sliding and combining the color filters 42 for use, it is thus possible to prevent erroneous edge position detection. The scattered light of the ring light 46 is reflected, and is irradiated to the object to be measured, and effective illumination is attained by a reflection screen plate 45 whose inclination angle can be changed freely so as to screen disturbance light, thus it is possible to eliminate an increase in illumination light in vain, therefore, it becomes difficult to generate halation on the screen.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an illuminating device for an image measuring device equipped with a camera, and more particularly to an illuminating device having a reflection shielding plate and a color filter integrally provided.

[0002]

2. Description of the Related Art A mechanism is provided for driving along X, Y, and Z axes orthogonal to each other (hereinafter referred to as X, Y, and Z drive axes), and a CCD camera is provided at one of the drive shaft ends. An image measuring machine as shown in FIG. 4 is well known, and mainly uses various types of image processing, in particular, an edge detection function.
It is used for dimension measurement of C parts and the like.

Usually, in this type of image processing, an edge position is detected by paying attention to a contrast difference in an image. However, for example, scratches and paint on the image,
If there is a material that greatly affects the change in contrast, such as a change in the material or a difference in the surface properties, a malfunction often occurs such that this position is erroneously detected as an edge position.

Therefore, conventionally, complicated operations such as adjusting the amount of illumination light or adjusting the angle of illumination have been performed so that such a problem does not occur. For example, as in an illumination device disclosed in Japanese Patent Application No. 5-183865, independent illumination systems are provided in advance for epi-illumination, transmission illumination, and oblique illumination, respectively, and the respective light amounts are adjusted. In addition, a complicated device such as an illumination unit disclosed in Japanese Patent Application No. 1-58098, which changes an illumination angle in conjunction with elevation of a camera, is required.

[0005]

However, in such a device, there is a problem that the illumination device becomes complicated and the price of the image measuring device increases. In addition, in order to weaken the relative intensity of disturbance light, which is considered to have an adverse effect on image processing, an operation of increasing the amount of illumination in the opposite direction is often performed. In this case, halation occurs in the image. There is a problem that it becomes easier.

SUMMARY OF THE INVENTION The present invention has been made to solve such a problem, and it is possible to prevent erroneous edge position detection in image processing due to scratches or painting on an object to be measured without increasing the amount of illumination, and It is an object of the present invention to provide an inexpensive manual operation type illumination device for an image measuring machine that efficiently irradiates an object with illumination light while suppressing the influence of disturbance light.

[0007]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides an image measurement system having an X, Y, Z drive shaft mechanism which is orthogonal to each other and a camera provided at one end of one of the drive shaft mechanisms. In the illumination device of the machine, a ring light that irradiates the object to be illuminated with illumination light, and a tilt angle that can be freely changed so as to reflect the scattered light from the ring light and irradiate the object to be measured and shield disturbance light It is characterized by comprising a reflection shielding plate having a reflection surface, and three kinds of color filters of red, blue and green with gradations slidably disposed on the front of the camera.

[0008] In the present invention, a red with a gradation,
By using a combination of three color filters, blue and green,
A synthesis filter corresponding to any color can be freely configured. Therefore, it is possible to make scratches and paints of all colors difficult to see. In addition, by appropriately adjusting the angle of the reflection shielding plate, it is possible to appropriately irradiate the illumination light to the object to be measured and, at the same time, shield disturbance light that is considered to adversely affect image processing. Erroneous edge position detection can be prevented without increasing the intensity of illumination light.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings. In all the drawings, components denoted by the same reference numerals represent the same components. FIG. 4 shows an external view of the image measuring machine system. The image measuring machine main body 10 includes a table 11 on which an object to be measured 13 is placed, and which is driven in the front-rear direction.
A CCD camera 12 housed inside the image measuring device main body 10 above and capable of being driven in the horizontal and vertical directions. The image photographed by the CCD camera 12 is input into the host computer 20 and various image processing, calculations such as dimension measurement and the like are performed. The host computer 20 includes a CRT 21, a keyboard 22, a mouse 23, and an operation panel 24.
And the printer 25 are connected to each other. In addition, a power source and a light source device 60 including a power source of the image measuring device main body and a light source of the illumination device are provided. A lamp serving as a light source of the lighting device is provided inside the device, and the amount of light of this lamp is controlled by a command from the host computer 20 and is configured to be guided to a ring light 46 inside the lighting device 40 by a glass fiber. I have.

Next, an image measuring machine system will be described with reference to the system block diagram of FIG. A video signal output from the CCD camera 12 is input to an A / D converter 14 and converted into a digital signal, and then input to a multi-valued image memory 15. The image information stored in the multi-valued image memory 15 is input to the CPU 30 in the host computer 20 for image processing.
Displayed at T21. The CPU 30 reads the position of each axis from the X-axis encoder 32, the Y-axis encoder 34, and the Z-axis encoder 36 of the image measuring device, and further drives the X-axis drive system 31, the Y-axis drive system 33, and the Z-axis drive system 35. The control is performed to constitute a so-called computer numerical control type image measuring device as a whole. Further, the outputs of the keyboard 22 and the mouse 23 operated by the operator are input to the CPU 30 through the I / F 31, and the driving operation of the image measuring device main body, the designation of the image processing position, the instruction of the image processing content, and the like are performed. .
Also, an operation panel 2 for operating the driving operation of the image measuring device.
4 is also input to the CPU 30. Furthermore, CPU3
Lighting device 33 through lighting control 34 according to a command from 0
Is turned on and off and simple light quantity adjustment is controlled. In addition, a memory 32 is connected to the CPU 30.

Next, a lighting device using the present invention will be described. As shown in FIG. 1A, the lighting device 40
It is connected to the optical barrel 41 of the image measuring device main body. Inside the illuminating device 40, there are provided three kinds of color filters 42 of red, blue and green, each of which has a gradation on the front surface of the opening where light from the object to be measured enters. As shown in FIG. 6, the color filter 42 has a substantially rectangular shape, and is provided with a gradation such that the color density gradually changes along the longitudinal direction. Each color filter 42 is slidable in the longitudinal direction.

Each color filter 42 is connected to a knob 43 for sliding through a slit 44. The operator grasps this knob and grasps the knob shown in FIG.
To adjust the position of the color filter 42 so as to freely set the color and brightness synthesized by the color filter 42. That is, the CCD camera 12
It is possible to freely set the color and brightness of the light from the object to be measured incident on the object. Therefore, for example, when there is a flaw or paint of a specific color on the DUT 13 in measurement such as edge detection or the like, the color filter 42 is appropriately set so that the flaw or paint of this color is difficult to see, and image processing is performed. Edge detection at an incorrect position can be prevented. Although all of the color filters 42 shown in FIG. 1 are configured to slide in the same direction, the respective color filters 42 are arranged so as to slide radially at intervals of 120 degrees, so that the color filters 42 are arranged in front of the opening 47. Each of the color filters 42 may be configured to intersect.
With such a configuration, there is an advantage that unevenness of gradation can be reduced.

Although not shown, it is also possible to arrange the color filter 42 in front of the ring light 46 so as to adjust the color of the illuminating light itself. This makes it possible to make the scratches or paint of a specific color less visible.

FIG. 1B is a bottom view of the lighting device 40. An opening 47 is provided at the center, and a ring light 46 is provided so as to surround the periphery. The ring light 46 guides light from the power supply and the light source device 60 shown in FIG.
6 is configured to emit scattered light. By separating the lamp of the light source, which is a heat source, and the power supply unit from the image measuring device main body 10, the influence of heat on the measurement accuracy and the failure of the measuring device main body due to the heat are prevented.

Although it is inevitable that the measurement accuracy is slightly deteriorated due to heat, it is possible to provide a smaller light source of, for example, a fluorescent lamp type inside the ring light 46 so as to be configured at a lower cost. In addition, this ring light 46
Can be divided into four, for example, at every 90 °, and the lighting and extinguishing of each can be controlled to easily adjust the light amount and direction of irradiation to the DUT 13.

Further, a reflection shielding plate 45 whose inclination angle can be freely adjusted is provided around the illumination device 40. The reflection shielding plate 45 reflects the scattered light from the ring light 46 to irradiate the object 13 placed on the table 11 as shown in FIG. 2 and at the same time, adversely affects the result of image processing such as edge detection. The disturbance light 51 which is considered to be exerted can be shielded so as not to hit the object 13 to be measured. Conventionally, in order to relatively reduce the influence of the disturbance light 51, the illumination light is increased. However, the use of the reflection shielding plate 45 of the present invention makes it unnecessary to increase the illumination light. . Therefore, there is an effect that the occurrence of halation in the image due to too strong illumination light is greatly reduced.

It is also possible to bend the reflection shield plate 45 inward to cover and close the ring light 46 itself so as to reduce the amount of light emitted from the ring light 46 to the object 13 to be measured. In this case, since a light control circuit or a light control mechanism for adjusting the light amount or turning on / off of the ring light 46 is not required, the light amount can be adjusted easily and at low cost.

Although the present invention has been described with reference to the preferred embodiments, the present invention is not limited to these embodiments, and can be modified without departing from the spirit of the present invention. For example, in the above embodiment, the apparatus for mounting the lighting apparatus of the present invention has been described as being limited to a so-called computer numerical control type image measuring apparatus having a driving mechanism as shown in FIG. 4, but also shown in FIG. Such a manual operation type image measuring device 10a can also be implemented.

Similarly, the illumination device of the present invention can be mounted on a microscope, a projector, and other optical devices, and the same effect can be expected.

Although only the rectangular color filter has been described in the above embodiment, the present invention can be similarly applied to a disk-shaped or fan-shaped color filter in which a gradation is provided in the circumferential direction. It is.

In the above embodiment, the reflection shielding plate is described as four rectangular flat plates. However, the number of the reflection shielding plates is not limited, and the shape of the reflection shielding plate is not limited to a rectangular flat surface. For example, the reflection shielding plate of the present invention can be constituted by a plurality of spherical pieces each having a concave mirror on the inside.

[0022]

As described above, according to the present invention, it is possible to prevent erroneous edge position detection due to scratches or painting on the object to be measured without increasing the amount of illumination light, and to suppress the influence of disturbance light to reduce the illumination light. It is possible to provide an inexpensive illumination device for an image measuring device that efficiently irradiates the object to be measured.

[Brief description of the drawings]

FIG. 1 is an external view of a lighting device according to the present invention.

FIG. 2 is an external view of a lighting device according to the present invention.

FIG. 3 is a system block diagram illustrating a configuration of an image measuring device system.

FIG. 4 is an external view of a computer numerical control type image measuring machine system.

FIG. 5 is an external view of a manual operation type image measuring machine system.

FIG. 6 is an external view of a color filter 42.

[Explanation of symbols]

 1 Image measuring machine system 10, 10a Image measuring machine main body 11 Table 12 CCD camera 13 DUT 20 Host computer 30 CPU 40 Lighting device 41 Optical column 42 Color filter 45 Reflection shielding plate 46 Ring light 51 Disturbance light 60 Power supply and light source device

──────────────────────────────────────────────────の Continued on front page (51) Int.Cl. ⁶ Identification code FI H04N 9/04 G06F 15/62 380

Claims (1)

[Claims] 1. An illumination device for an image measuring machine having X, Y, and Z drive shaft mechanisms orthogonal to each other and having a camera at an end of one of the drive shaft mechanisms, wherein a ring light for irradiating an object to be measured with illumination light. A reflection shielding plate having a reflection surface configured to change the inclination angle so as to reflect the scattered light from the ring light to irradiate the object to be measured and shield disturbance light, and slide on a front surface of the camera. Red, blue, and green color filters with gradations that can be arranged freely,
An illumination device for an image measuring device, comprising: