JPS59143908A - Surface roughness detecting device - Google Patents

Abstract

PURPOSE:To detect surface roughness highly sensitively, by constituting a device, by a first optical system and a second optical system, whose light axes are intersected each other, a divider, which obtains the ratios of the outputs of a light source device and first and second light receiving devices, and an operator, which performs the inverse logarithm operation of the output of the divider, and correcting the difference in surface reflectivity caused by the quality of the surface of a material to be measured, the state of the surface, and the like, even though light projecting and receiving angles, distance between the surface to be measured, and the like are fluctuated. CONSTITUTION:The optical fibers of a first optical system 11 and a second optical system 12 are formed by bundling the light projecting fibers in a circular shape in the inside and bundling the light receiving fibers in a concentric shape at the outside thereof. The area ratio of the optical fibers is 1:1. A first light receiving device 15 and a second light receiving device 16 are phototransistors, which perform photoelectric conversion of the received reflected light beams into electric signals. The output electric signals are outputted to a divider 17 through amplifiers 19. An operator 18 is an inverse logarithm operator, which operates a central-line average roughness Ra based on the ratio between the output Fo from the first light receiving device 15 and the output Fe from the second light receiving device 16.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement of a surface roughness detection device, and more particularly, to a surface roughness detection device that detects surface roughness from the reflectance of the dazzling light on the inspection surface by projecting light onto the inspection surface. This invention relates to improvements in detection devices.

Conventionally, there is a stylus-type surface roughness detection device as one of the surface roughness detection devices. There is a problem in that contact with the surface deteriorates the surface condition and makes it impossible to make accurate measurements.

In contrast, devices have been adopted that optically non-contact (surface roughness measurement) without damaging the surface of the object.

This non-contact surface roughness detection device using optical means is
For example, (, 11 light) is projected onto the surface of the object to be measured through an optical system consisting of a fiber, etc., and the reflected light beam is
;C: The surface roughness is detected from the irregularities on the surface of the object.

Such surface roughness detection devices have the advantage of being able to perform non-contact measurements, but the output of the anti-Q'J rays on the surface of the object to be measured may be slightly distorted. Projection angle, angle of light reception by the optical system, distance between the optical system and the measurement surface11j .

This invention has been made in view of the above-mentioned conventional problems, and includes such things as the angle of light projection and reception, the distance El11 between the surface to be measured and the optical system, the angle of the optical axis between the surface to be measured and the optical system, etc. It is an object of the present invention to provide a surface roughness detection device that can detect surface roughness with high sensitivity even if there is a variation in surface roughness.

In addition, this invention (1/J day, large surface condition, etc. of the surface of the object to be measured, etc.)
The following four objectives are provided: to provide a surface roughness detection device that can detect surface roughness at both temperatures.

This invention includes a first optical system and a second optical system whose optical axes intersect with each other, and a light source device that projects light onto an inspection surface through at least -h of the first optical system and the second optical system. a first light receiver that receives the anti-Q′l light from the inspection surface via the first optical system;
A second light receiver that receives light from the optical system at fF L, a divider that calculates the ratio of the output horns of the first light receiver, l-5, and the second light receiver, and a divider quantity horn by this divider. Anti-logarithm calculation
The above object is achieved by forming a surface roughness detection device (for detecting roughness) and a roughness detection device (Table 11).

Further, the present invention achieves the above object by arranging the forces of the first optical system and the second optical system in the surface roughness detection tool u7f so that their optical axes are perpendicular to the inspection surface. ) It is composed of Zuruchino.

The father of this invention is the surface'! 1. The first optical system A3 and the second light beam are placed in the first optical system A3 and the second light beam. system,
The above objective is achieved by arranging the optical axes at an intersection angle of 0 or 90° with respect to the state of the inspection surface.

Also, this invention L1. , ii? The above object is achieved by 15 in the surface roughening device j, wherein at least one of the first) 1C optical system and the second optical system is composed of an optical fiber having an outgoing path i1J and a returning path. It is.

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

As shown in Fig. 1, this first series has an optical axis (
1:l! The first optical/optical system 1, such as the first optical system 11J3 and the second optical system 12, which intersect with J- at an angle of 30'
1J5'': a light source device 14 that emits light onto the inspection surface 13 via the second optical system 12; and a first light receiver that receives reflected light from the inspection surface 13 via the first optical system 11. 15, a second light receiver 16 that receives reflected light from the inspection surface 13 via the second optical system 12; and a first light receiver 15.
and a divider 17 for calculating the output ratio of the second light receiver 16, and an arithmetic device for calculating the inverse logarithm of the divider output by this divider and 17; This is the configuration of the device.

The first optical system 11 and the second optical system 12 are each composed of a horn fiber having an outgoing path and a returning path.

These optical fibers of the first optical system 11J3 and the second optical system 12 have optical fibers for projecting light bundled in a circle inside,
Moreover, light receiving optical horn fibers are bundled in a concentric ring shape on the outside thereof, and the area ratio of the light projecting and light receiving optical horn fibers is 1:1. .

The first light receiver 15 and the second light receiver 16 each photoelectrically convert the received reflected light beam into an electric signal) 711
1 to 1 are transistors, and their output electric signals are outputted to the splitter 17 via an amplifier 19, respectively.

181, jt of the output Fo from the first light receiver 15 and the output F e from the second light receiver 16.
F o = "-' e =" Based on I-o, it is considered to be an anti-logarithm calculation device that calculates the center line average roughness l' (a = 1o (h8)), where M , K is for the object to be measured (A for processing conditions, etc.): There are different definite sentences.

- When measuring the phase height of the inspection surface 13 using the surface (i) size detection device shown in FIG. 11 is arranged so that its optical axis is perpendicular to the inspection surface 13, and the second optical system 12 is arranged at an intersection angle with the first optical system 11 whose optical axis meets the inspection surface 13. They are arranged so that they intersect with θ.

Next, an inspection is performed using the above-mentioned embodiment apparatus.
The principle of measuring the surface roughness of G and the theory on that principle.

In the experiment, the first optical system 11 and the second optical system 12) were equipped with an optical fiber for light projection with an autonomous diameter of 0.8' and 11 m on the inside, and a ring-shaped optical fiber with an outer diameter of 1.2 m on the outside. Each bundle of 300 optical fibers in the north has an area of 1:
It was set to 1. Further, the intersection angle θ between the first optical system 11 and the second optical system 12 was set to 30'.

The light source device 14 includes a tongue lamp and a first lamp.
The optical system 11a5 and the second optical system 12 illuminate
7. Bo'/l'? 41J, about 1.5 tiles, 1st optical system ゛1 and 2nd optical system 12 tip inspection M1η] 13
Open the cap of the saw about 2 to 3 times.

In general, it is known that in the case of 1 grinding, the surface inclination angle of the 1O1 surface curve il is the normal component li, but if the center line average roughness is 1 and a is 0.2 μm A3 and 0
．． The length of the surface roughness standard piece of 8L1m, the result of the experiment,
The surface inclination angle b1.1.
It became like the histodaram shown in Figure 2 (a) J5 Yohi (0).

It can be seen that the Hiss I-gram shown in FIG. 2(a) (1) shows a normal distribution, and that the theoretical value and the experimental value are approximately equal to each other.

Therefore, let the surface 1lJ1 oblique angle be O5, and the table if+11L
+ to the standard 4 of sada r1 kakumin i 11! Taking the difference as σes, the function f (θS) is 2πσes... (1)
−(to be expressed,.

Therefore, regarding the reflected light from the two optical systems '11 and 12-(-)'N?ii+i13, which is received, l1
Here, the optical neutron beam has a unique acceptance angle (light) due to the aperture VIN, △ (incident angle at which the neutron can receive light), so the detection activation is limited to one river or be done. The first one used for the actual test
The optical system 11 (υ) and the vertical light fiber Fo of the second optical system 12 and the oblique light horn fiber Fe are 8 to N,
/10.26, and the effective acceptance angle is about 7", which is inferior. If the total amount of reflected light from the measurement object is expressed as Φ, then the amount of reflected light that Noaiba can receive can be expressed as constant a
, Ill The effective acceptance angle C' of the optical shear bar is determined.

Here (゛, Detect the amount of reflected light that the optical fiber can receive!
If we call this the rate Q, then it becomes Q-Φ Φ (/I).

As shown in FIG. 3, the reflection angle θr of the light reflected on the surface of the object with the deflection angle θS is θr”2O5 (5).

Therefore, the detection 111i1 of the vertical rivet Fo is
±3 relative to the center of the normal distribution as shown in Figure 4.
5', and the slope of θ-30' - Nononi Iha 1
- The detection probability Qe of θ is obtained by performing integration over a range of 3.5° around a position deviated by 1 from the center of the normal distribution.

Figure 5 shows the results of the four poems with detection probabilities Qo and Qe.

Qo, Qe and Qo -Qe, □Qo fko-
1) I-(' z-I Find the Pi approximation using the least squares method, Qo = 1.09-0.081ogσθs - (6)Q
e −−0, 11+0. 191og 0t3
6- (7) Q o ---1, 671-1, 7
2lo Ri σe s − (F3) ('I”a relation coefficient γ=o, 97> roar.

Figure 916 shows the urine condensation measured with 1.2 < face value r% J' + Nitsui. Here (゛ is Htl
o , F e it> and l: o = F B' l
” o 'I:') Obtaining the logarithmic function approximation using the least squares method, L-o=8.90-6.2710!J σes-<9
nt e-〇, 'l 6+'l, 221ogσes...
・For (1o), o =-! 3, 484 11.
591og σ θ S...(11) Correlation coefficient γ-0,95) I yelled.

The tlIJ relationship between the surface (circle 1 direct numerator 1' θS) and the ratio Fo of the two systems of light 7 for the width difference σθS is as follows: ]!l of the detection probability in Figure j)
! It is clear that compared with Ronkei Sakusho, there is a qualitatively high degree of consistency.
The surface roughness is reduced to A! 'J > m is Okawa-(not □1zoko-C1σe5-Ra). t−j, σe 5−−−11.03+6.
961og l dog a...(12) Obtained (correlation coefficient γ-0,99) 1c.

In the same work, [When finding the relational expression of oRa, Fo--6,0
7+4.221o<+l'<a...(13) ('lfJ function r=0.99) was obtained (see Figure 8). i,lllIJII
In the case of measuring the center line average roughness Ra of Lir+i, it can be expressed by the following general equation.

F o =M+ K 1ofJ Ra −(1
4) Therefore, 1pe a -1o"p-') ...... (I E) ). However, fvl is a constant that varies depending on the conditions of the measured object, etc. 1 So, should we fix the relationship between SoC Tsuno'Iha and Outkado0 Ra?
11, reverse gradient, 2'! A demonstration of the epidemic?
It will be a good thing.

Therefore, in the surface 1u height detection device according to the above embodiment, the measurement conditions in the performance device 18 are as follows: 1) the constant M in the expression (1/'I) and the expression (15) in 1j;
and K 'a' of the object to be measured, addition [set in advance according to the conditions, etc.'C] is the first optical system 11 and the second optical system 12 fp and the first branch/optical device. , l13 and the second optical receiver, the surface roughness ('51Ra) can be detected.

As a result of measuring the surface first horizontal strip 1"F- (1" F-), the above-mentioned method (refer to Figure 9 shows that the surface first [standard 1"1") was measured by recessing.

As is clear from FIG. 9, the experimental results substantially match the actual phase of Table 1a1.

It should be noted that the above embodiment device has a first optical system 11 and a second optical system R.
C light is projected from both N12 onto the inspection surface 13 via the light source device 14! However, it is also possible to project light from only one of the optical systems.

In addition, in the embodiment described above, the optical axis of the first optical system 11 or the inspection surface 1
is perpendicular to 3, and Ji
゛The optical axis of the system 12 is 30° with respect to the optical axis of the first optical system 11.
are arranged so that they intersect at the angle +a of the inspection surface 13. However, the present invention is not limited to this;
The angle of oblique angle 1 and the intersection angle θ of both optical systems 11 and σ12
1. 1. In the state of the L inspection surface 13. Jin, Shiku O/θ〈90°
The range is arbitrary (if θ≧90°, no reciprocal light can be received).

Also, l'+6 #L first optical system (b and second optical system 11
．． 12 is ) (outward trip o': and return trip plus 1ift)
"There are 416 neu-bars" (although the present invention is not limited to this, for example, the first optical system may be used for forward and return paths, and the second optical system may be used for 5ISi paths). In the history, the optical system was constructed by a system other than the one described in Section 1. The surface roughness can be detected, and therefore the light emitted by the optical system, b-receiver) is adjusted to the angle 1, the optical path, ', the distance between the limit inspection surface and the inspection surface. When the angle of It has the helpful effect of being able to expand.

Moreover, this invention is capable of detecting a concrete center line average roughness, which is different from the conventional surface roughness detection device which is designed to provide an abstract output related to surface roughness. It has one obvious effect: it increases the amount of water.

[Brief explanation of drawings]

Fig. 1 is a block diagram showing an embodiment of the surface cutting device according to the present invention;
Figure 3 is an optical diagram showing the relationship between the surface IC+4 slope angle in the cross-sectional curve of measurement 1r11 and the light reflection angle in the slope table 1f11. Figure 5 shows the detection probabilities in two optical fibers and the theory of the ratio of these detection 1i'ff rates. The diagram, Figure 6, shows the output values of the two-system optical fiber and their ratios, l1lllllll
'I is a small scale diagram, and Figure 7 is the surface ILnfu! of an unspecified surface. 1
A diagram showing the experimental results of the relationship between the standard deviation and the average roughness of the center line of the surface. Figure 8 shows the ratio of the output of the two threads Uc' to the average horn fiber output and the center line. Relationship with average roughness 4 A diagram showing the experimentally determined results, Figure 9 shows the relationship between the measurement axis 1.1 and the actual 1.
- It is a line diagram showing the relationship with appearance. 11...1st optical system, 12...1st? Optical system,
I3...Inspection surface, 14...) (device N, 15...1st receiver, 16...2nd
Receiver, 17... divided bK: jj÷,
18... Iri 4 [)
'n limb 1 light, θ...reverse angle. 1) person) public l1l-: i-1i. <+,, 1 or 1 person) Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 f: a 2 Figure 6 Kurin

Claims (1)

[Scope of Claims] (1) A first optical system and a second optical system whose optical axes intersect each other, and a light source that projects light onto the inspection surface via at least one of the first optical system and the second optical system. a first light receiver that receives reflected light from the inspection surface via the first optical system; and a second light receiver that receives reflected light from the inspection surface via the second optical system. , a divider for calculating the ratio of the outputs of the first light receiver and the second light receiver, and an arithmetic device for calculating the output of the divider by the divider using an anti-logarithm. Detection device. (2) One of the first optical system and the second optical system is arranged such that its optical axis is perpendicular to the inspection surface. (3) The first optical system a3 and the second optical system have an intersecting angle 1 θ of their front axes depending on the state of the inspection surface (, O〈θ〈
Special 8 characterized by being arranged at 90°
'f A surface roughness detection device according to claim 1. (4) At least one of the first optical system and the second optical system is constructed from an optical fiber having an outgoing path and a returning path. The surface roughness detection device described in .