KR0171688B1 - Method and equipment to measure verticality without contact - Google Patents

Abstract

The present invention relates to a non-contact verticality measuring method and measuring apparatus.

The method combines a partial image of the lower part of the column and a partial image of the upper part of the column into a single image through an optical system, in order to measure the perpendicularity of the straight column installed perpendicular to the reference plane. The image is taken by a video camera installed parallel to the reference plane, and the slopes of the two lower partial images and the two upper partial images are calculated from the combined image, and the slopes are compared to measure the verticality of the image acquisition camera. Way.

In addition, the apparatus is coupled to the optical system for displacing the moving path on the column of the column so as to obtain by selecting only the partial image of the lower end of the column and the partial image of the upper part of the column, the relative position is fixed to the optical system, It is possible to reciprocate to adjust the relative position with respect to the pillar, using the image pickup camera installed in parallel with the reference plane in the near position and the image obtained from the camera, the signal processing to measure the verticality of the pillar Including the processing and control system.

Description

Non-contact vertical measuring bar up and vertical measuring device

1 is a plan view illustrating a deck for video and a perspective view of the deck post.

2 is a view for explaining the law of refraction used in the present invention.

Figure 3 illustrates a displacing glass used in the present invention.

4 is a view showing a state of the image through the displacing glass used in the present invention.

5 is a plan view and a front view and an image on a monitor, illustrating an apparatus for measuring verticality of the present invention.

6 is a diagram illustrating a relationship with an optical path of the present invention.

7 is a block diagram of the measuring device of the present invention.

8 is a schematic view of a device centering on the mechanism of the measuring device of the present invention.

* Explanation of symbols for main parts of the drawings

51: lamp 52.61.89: pillar (post)

53.87: right angle prism 54.88: upper displacement

54-1.54-2.62: Phase Displacement Glass

55.71.85. Image pickup camera 63: Screen

72: Video Multiplexer 73: Image Grabber

74: bus 75: main computer

76: system monitor 77: display monitor

81: base plate 82: deck

83: Feed Device 84: Post Guide

86: Adapter

The present invention relates to a method and apparatus for measuring the verticality of a structure such as a column installed perpendicularly to the reference plane, in particular, to be suitable for enabling the non-contact precise measurement of the verticality of the odometer posts of the 8mm VCR deck. A contactless vertical measuring method and a vertical measuring device.

With the rapid advancement in multimedia technology, the spread of VTRs is growing at an alarming rate. As the VTR market expands, technological competition for high-performance and miniaturization to increase the added value of products has become fierce. Accordingly, the miniaturization of products has continuously increased the required precision of components, and the introduction of advanced manufacturing technology has been required. However, these small products still have a very high defect rate, and at the present time, the production cost is very high due to high wages, and defective products are a big obstacle to securing international competitiveness.

In order to accurately record and reproduce video signals, audio signals and control signals recorded on the video tape, the video tape must pass exactly through the fixed position of the head drum and the audio / control head. It is the multiple posts of the deck odometer that are responsible for this function.

Some posts are designed to be adjustable, but some are riveted and fixed to the base. Fixed posts can not be calibrated after the deck has been manufactured, resulting in a major problem after assembly.

(A) of FIG. 1 illustrates the deck running system 10 of a small VCR, and the main fixing posts 11 constituting the compact VCR are formed as shown in the figure.

Since the posts should be installed perpendicular to the base, and the required precision is about tens of micrometers / 10 mm, it is necessary to develop a precise inspection technique.

If the state of the fixed posts 11 is not maintained vertical as assumed, it is difficult to maintain the state of the odometer only by adjusting a few posts, and in some cases, a situation of inhibiting tape running occurs.

If the verticality of the fixing posts 11 is maintained well, it will not only facilitate the adjustment work in the final manufacturing stage, but will also play a big role in stabilizing the odometer operation. It can be very helpful in finding out the process.

Conventionally, as a method of measuring the verticality of the posts of the deck traveling system, it is a contact inspection method, which is a method mainly used in large corporations in Japan and Korea at present. This is also a method mainly used for the inspection of conventional VTRs.

However, as the deck becomes smaller and smaller, the size of the posts becomes smaller, which causes the posts to be damaged due to the probe contact pressure of the measuring device or the diameter of the posts becomes smaller, resulting in a large error in the test result. There was a problem causing.

The present invention has been made to solve the problems in the above-described contact verticality measurement method using a non-contact measurement method that can measure and examine the verticality without applying a physical force using the image processing method.

As a method of evaluating the vertical degree, there is also a method of having the inclination of the post with respect to an arbitrary plane, but here, as shown in (b) of FIG. 1, the deviation from the reference position with respect to the post 11 having a length of 10 mm (D) It is defined as Currently, the verticality condition required for an 8mm VCR is 40 mu m and the verticality condition for quality control is 16 mu m.

Since the inclination of a straight line lying on an arbitrary plane is represented by two angles with respect to the plane, the verticality inspection task needs to be measured at two or more different places.

However, if, for example, you want to measure the posts of a small VCR deck odometer, the heights around the posts 11 to be inspected, as shown in FIG. Access to inspection equipment is not easy. Therefore, a single post needs to be measured more than once in a confined space, requiring a very careful design of the device.

By the way, especially in the case of a post of a deck driving system of a small VCR, the size and shape vary depending on the product or function, but the length is about 12-15 mm and the diameter is about 10-12 mm. In addition, the surface roughness is 0.8s class, the reflectivity (reflectivity) to light shows a property close to Lambertian.

The invention uses Snell's law for refraction, and according to the Fermat's principle, light travels in a path that takes the least propagation time. Thus, as shown in FIG. 2, the light passing between two different objects eventually causes refraction that satisfies Snap's law as shown in Equation (1).

Therefore, as the second tile, when that the refractive index of the light incident on the medium n1, relatively smaller n ₁ the refractive index in the interface the medium n2 forms as angle of incidence α in the medium of the n _2, the light in the medium of the n ₂ Proceeds by bending at the refraction angle of β.

Further, as shown in (a) of FIG. 3, if the glass plate 30 having a flat surface on both sides and a thickness T is inclined by θ in the horizontal plane, and the light in the vertical direction is shining upward from the bottom, the light passes through the glass. The path of is changed, but the direction is the same as when first entering, and only position change D occurs. This displacement D is determined by the following two equations (2) and (3).

As a result, it is clear that when the equations (2) and (3) are put together, the displacement D is determined by the thickness T and the inclination θ of the glass plate.

Therefore, when the two glass plates are connected to each other in a V-shape at a predetermined angle as shown in FIG. 3 (b), only light emitted from both ends of the actual image 31 passes through the glass plate. Therefore, the obtainable image 32 has the same effect as the longitudinal reduction.

In this case, the problem of aberration does not occur greatly, so that the degradation of the image is eliminated, and the glass plate has an advantage of not having to pay much attention to the arrangement because only the position of light is changed.

FIG. 4 is exemplified to compare images obtained when the phase shift glass is not used and the phase shift glass.

As shown in (a) of FIG. 4, when the phase shift glass is not used, only a part of the measurement target 42 is observed, and in general, when the tilt is very small, it becomes difficult to measure the tilt. However, as shown in (b) of FIG. 4, when the phase displacement glass 43 is used, the images 43-1 and 43-2 at both ends of the measurement target 42 can be collected in the center to obtain a single screen. As a result, the effect can be clearly observed even in the case of having a slight slope.

As described above, when the image is obtained through the phase shift glass even at the same inclination, a large change occurs, thereby enabling accurate measurement.

The present invention relates to a measuring device for implementing the non-contact verticality measuring method as described above, in order to measure the verticality of the linear pillar is installed perpendicular to the reference plane, on the column, a partial image of the column bottom and The optical system displaces the movement path on the column so that only a partial image of the maneuvering upper part can be obtained by selecting it, and the relative position is fixed to the optical system, and the reciprocating movement is possible to adjust the relative position to the column. And an image processing camera and a control system for measuring the vertical degree of the pillar by signal processing the image pickup camera installed in parallel with the reference plane at the position.

At this time, the optical system is a portion of the pillar reflecting the light reflected in a direction perpendicular to the camera's incident optical axis parallel to the camera's incident optical axis, and the light reflected from the reflecting portion and proceeds directly from the pillar It is composed of the phase displacement part made by forming the flat glass in V shape to change the two light paths to narrow the gap between the two paths.

The reflector may be implemented using a right-angle prism, and the phase shift part is formed of a material (glass) having a refractive index larger than the medium of the measurement space, the first phase shift pair arranged in a V shape in the direction of the pillar, and the length of the pillar. It can be implemented by having a second phase shift pair arranged in a V-shape in the direction.

In addition, the optical system may further include a light source unit for illuminating the pillar to be incident on the reflecting portion and the image displacement portion in a direction perpendicular to each other reflected from the pillar in consideration of the positions of the reflecting portion, the pillar, and the image displacement portion. It may be. At this time, the light source unit can also be implemented as a linear light source made of a bundle of optical fibers provided next to the pillar.

The image processing and control system includes an image processing unit which receives a signal from an image pickup camera, and processes the image, and a main computer for calculating the tilt of the column using the signal and outputting the signal to the screen.

In addition, the perpendicularity measuring device of the present invention, in order to measure a plurality of pillars at the same time, a plurality of optical systems formed for each of the plurality of pillars, a plurality of imaging cameras formed one for each of the optical system, and the plurality of imaging By using a plurality of images coming from the camera, it may be formed by including an image processing and control system for each signal processing to measure the verticality of each pillar.

At this time, the image processing and control system further comprises a multiplexer card to receive a plurality of images.

The method of the present invention is a vertical measurement method for measuring the verticality of a straight column installed perpendicular to the reference plane, and the partial image of the lower part of the column and the partial image of the upper part of the column perpendicular to each other through the optical system Combine the images into a video camera installed parallel to the reference plane, and calculate the inclination of the two lower part images and the two upper part images, i.e., the four pillar images, By comparing these inclinations, the perpendicularity to the image acquisition camera is measured.

As an embodiment of the present invention will be described in detail taking the case of measuring the verticality of the posts of the compact VCR deck odometer as an example.

Vertical measuring apparatus of the present invention

Optical system

Image processing unit

Mechanism

Can be divided into general control and display.

Looking at each of the parts, first, as shown in (a), (b) of Figure 5, the optical system serves to receive the image of the deck odometer post 52 and deliver it to the CC camera 56, zoom lens , As the barrel 55, the image displacement section 54, two pairs of V-shaped glass plates 54-1, 54-2, the focal length correction prism 53, the CCD camera 56, the illumination device 51 Consists of.

In designing the optical system, the requirements are first, because the lens is hard to approach each post, the working distance should be large. Second, the size of the deck itself is small, so the lens and camera should be reduced. In order to achieve the magnification, the V-shaped glass plate should be closer to the target post.

The device is equipped with five identical optics for each post that meet the above requirements. In order to obtain the inclination of the post in the three-dimensional space, it is necessary to measure the inclination at each of two points perpendicular to each other, so that ten optical systems are required.

However, since the place around the deck is cramped, it is virtually impossible to install ten CCD (charge coupled device) cameras for imaging.

Therefore, in the present invention, as shown in FIG. 5, the image from the side can be viewed from the front through a 90 ° prism, and the two images can be entered into the view field (about 3 mm) of the CCD camera. The V-shaped glass was installed.

At this time, in order to correct the optical paths of the two images, the length of the prism (reflector) 53 reflecting at 90 ° must be accurately processed by calculation. In this way, the number of optical systems was reduced to five, resulting in the simplification and cost reduction of the whole device.

The lighting device was only used in the specific direction of the post, and the installation space is very narrow, so it was used to make a vertical straight light source using a bundle of optical fibers.

As shown in (c) of FIG. 5, the image received at each post is represented by a quad screen 56, in which the left portions 57-1 and 57-2 and the right portions 58-1 and 58-2 are Each corresponds to an image viewed from the front and an image viewed from the side surface perpendicular to the image.

Also, as shown in (a) and (b) of FIG. 6, the image processing method considers only one part of the image which is incident directly from the post 61, and as shown in (a) of FIG. Set as shown in the picture. Since the value obtained from the CCD camera is between 0 and 255 brightness values, the brightest point y at each x coordinate can be obtained. Using the n data thus obtained, equations of a straight line are obtained by the first order regression using the following equations (4) and (5), and then the y-coordinate of the point a1 corresponding to the y-intercept is obtained.

In a similar way it is obtained a a ₂ a ₁ and Car Guide Obtaining a d (pixel) of a ₂ value is measured that deviates from the direction of the extent of two locations spaced apart by h from each other on the post. To find the exact slope measured in one direction, correct it by the following equation (6).

At this time, xscale and ysclae should be accurately measured in advance as a value indicating how far a pixel is actually on the screen. In this way, the slope 2 is also obtained in other directions perpendicular to each other, and the actual slope and the tilted direction are obtained by the following equation (7).

The image processing system used DT Translation's DT-2862 board and a DT-2859 multiplexer card to receive images from five CCD cameras.

7 is a block diagram of the entire apparatus including the image processor.

First, an image video signal from the camera unit 71 is input from the video multiplexer card 72 to be digital image data on an image grabber 73, which is loaded on the bus 74 to the monitor 77. Is displayed and stored in memory. The data carried on the bus 74 is analyzed and processed on the main computer 75 so that the results of the measurements are shown on the system monitor 76. The overall control of these operations is of course done by the computer processing the program.

8 is a schematic front view and a plan view of the mechanism of the present invention. Here, the configuration of the optical system and the camera unit of the entire equipment can be seen.

As shown in (a) of FIG. 8, the mechanism part has a relative position between the apparatuses 83 and 84 for feeding the deck by the operator and the posts 89 and the optical systems 87 and 88 of the deck 82 within 0.05 mm. It consists of the base plate 81 which fixes it precisely. The deck feeding device is composed of a pneumatic cylinder and a guide post (84). The camera 85 is also seated on the base plate 86 via an adapter 86.

(B) of FIG. 8 is a partial schematic view of the device centered on the mechanism, and as mentioned above for the measurement of the post of the deck odometer, the optical system 87, centered around the main stationary post 89 of the deck odometer, The planar positional relationship between the camera 88 and the camera 85 is shown.

In addition, the general control and display unit is composed of a main computer and monitor that collectively manages each optical system and image processing unit, and a S / W of a menu screen processed by a picture so that an operator can easily check the inspection results. The operator can immediately see on the screen whether or not the amount of vertical error of each post on the screen.

On the other hand, the non-contact vertical measuring method and verticality measuring device of the present invention measures the verticality of the column-shaped object requiring the installation perpendicular to the reference plane, as well as the post of the deck odometer of the small VCR described in detail above. Can also be used to. In particular, the effect is great on the verticality of the structure installed in a small space.

The non-contact vertical measuring method and the vertical measuring device using the same according to the present invention can perform measurement without actually contacting the measuring object by using the optical principle, unlike the conventional contact measuring method. Solve problems such as occurrence of error. In addition, it can be sufficiently applied to the measurement for the object with a small measurement space.

In addition, since the defect rate of the product can be lowered through the ease and accuracy of the measurement, the quality competitiveness of the product can be improved, and in particular, when used for measuring the posts of the deck odometer of the small VCR, the verticality of the fixed boosts If it is well maintained, it will not only make adjustments easier in the last step, but will also play a big role in stabilizing the odometer operation and may have the advantage of finding a problem-prone process in the installation of the current fixed post.

Claims (9)

In the vertical measurement method for measuring the verticality of the straight column is installed perpendicular to the reference plane, a partial image of the lower part of the column and the partial image of the upper part of the column viewed from the right angle direction are combined into one image through the optical system The image is taken by a video camera installed to be substantially parallel to the reference plane, and the slopes of the lower and upper four images are calculated from the combined image, and the vertical angles of the reference planes are measured. Non-contact vertical measuring method. A verticality measuring device for measuring the verticality of a straight column installed perpendicular to the reference plane, comprising: an optical system for displacing a path of light reflected from the pillar to be measured and the optical system and a relative optical beam And an image processing and control system for measuring the vertical degree of the column by processing the image signal obtained from the camera and an image pickup camera installed to adjust the position. The optical system of claim 2, wherein the optical system comprises: a reflector configured to change a path of light so that a part of the light reflected from a portion of the pillar in a direction perpendicular to the incident optical axis of the camera is parallel to the incident optical axis of the camera; And a phase displacement unit for reducing the distance between the two paths by changing the paths of the light reflected from the reflecting part and the two light proceeding directly from the pillar. The light source unit of claim 3, further comprising a light source unit configured to illuminate the pillar to be reflected by the pillar and incident on the reflector and the phase displacement unit in consideration of positions of the reflector, the pillar, and the phase shift unit. Verticality measuring device. 5. The verticality measuring apparatus according to claim 4, wherein the light source unit is a linear light source formed of a bundle of optical fibers arranged next to a pillar. The apparatus of claim 3, wherein the reflector is formed of a right prism. The V-shaped flat plate of claim 3, wherein the phase shift part comprises a first phase shift pair consisting of a pair of V-shaped flat glass glasses arranged at right angles to the longitudinal direction of the column, and a V-shaped flat plate arranged in the longitudinal direction of the column. And a second phase displacement pair composed of glass pairs. The method according to claim 2, wherein a plurality of optical systems each formed for the plurality of pillars, a plurality of imaging cameras formed one for each of the optical systems, and the plurality of imaging cameras are provided to measure the plurality of pillars simultaneously. And an image processing and control system for measuring a vertical degree of each pillar by signal processing the plurality of images by using a plurality of images. 10. The apparatus of claim 8, wherein said image processing and control system comprises a video multiplexer card and an image grabber card to receive a plurality of images.