JPH02223813A - Transparency distortion evaluating method for laminated glass plate - Google Patents

Abstract

PURPOSE:To accurately and automatically evaluate transparency distortion by measuring the uneven shape of the outside surface of the laminated glass plate and predicting the transparency distortion of the laminated glass plate. CONSTITUTION:The unevenness of the surface of the glass plate is found in the width direction of the glass plate, the refraction of light is found from the uneven shape by geometric optical calculation, and the refraction of the laminated glass is found from the uneven shape of the outside surface of the two glass plates. A measuring person views the motion of a lattice pattern on a screen as transparency distortion through the laminated glass plate. The relation between the characteristic parameter of the dynamic variation pattern and a flicker angle which is found by a conventional flicker functional test is found in advance to calculate a flicker angle. Consequently, the flicker angle of the laminated glass plate can be calculated only by measuring the surface shape of the glass plate.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a method for evaluating perspective distortion of a laminated glass plate, and particularly to a method for evaluating perspective distortion of a laminated glass plate suitable for evaluating the quality of laminated glass for automobiles.

[Prior Art] Generally, laminated glass for automobiles is manufactured by laminating two glass plates with a synthetic resin interlayer such as polyvinyl butyral interposed between them.

By the way, when such a laminated glass is used as a window glass of a car and the outside world is viewed through the window glass from inside the car, a phenomenon in which the view of the outside world flickers, that is, perspective distortion may occur. Various causes of perspective distortion have been estimated, and one of them is considered to be irregularities existing on the surface of a float glass plate for laminated glass. It is said that this perspective distortion is generally more significant as the surface irregularities of the float glass plate for laminated glass become larger.

Therefore, in order to provide a laminated glass plate free of perspective distortion as a laminated glass for automobiles, it is necessary to quantitatively and reliably evaluate the perspective distortion of the laminated glass plate as a product.

Conventionally, as testing methods for this purpose, the Shiraki Industrial Standards include a perspective distortion test and a double image test. These two test methods quantitatively evaluate image distortion caused by laminated glass plates, but because they are static test methods, they cannot evaluate subtle flickering in the external scenery seen from inside a moving car. There will be cases. On the other hand, a dynamic test method has been proposed that simulates the situation of viewing from inside a moving car, and this is usually called the flicker sensory test method. The flicker sensory test method is carried out according to the following steps 1 to 2.

■ Laminated glass plates are produced by laminating glass plates that are continuously produced using a float-type plate making machine with a synthetic resin interlayer interposed between them.

■ On the approximately 200cm square white board shown in Figure 6,
A grid screen 1 with black lines at cm intervals and a sample stand 2 on which a laminated glass plate is placed are prepared, and the screen 1, sample stand 2,
Place measurer 3.

■ On the sample stage 2, the angle θ with the horizontal is θ = 3.
A standard sample plate, which serves as a reference for perspective distortion, is set so that the angle is 0°.

■Measuring person 3 looks at screen 1 while moving his head up and down. At this time, the flicker in which the grid pattern on the screen 1 slightly moves up and down is used as the standard for flickering.

■Next, set the laminated glass plate 4 on which the flicker sensory test will be conducted on the sample stand 2, and adjust the inclination angle θ of the sample stand 2 so that the flicker at the point where the flicker is large is the same as the flicker based on the criteria in (■) above. Adjust.

(2) The angle θ obtained in (2) becomes the flicker angle that quantitatively represents the quality of perspective distortion of the laminated glass plate.

[Problems to be Solved by the Invention] The flicker sensory test method, which simulates the situation in which the outside world is viewed from inside a car, quantitatively evaluates the dynamic perspective distortion of laminated glass plates. Since this is a test, there is inevitably individual error by the measurer, and this individual error arises from differences in the individual's sense of flicker. Particularly in this flicker sensory test, there are various patterns of flickering, and the sensation of these flickers differs depending on the individual, so judging them all at the same time is a source of greater individual error. For this reason, in the conventional flicker sensory test, errors occur clearly in the measured values when different operators are used, and errors also occur in the measured values even when the same operator uses different measurement dates and times. Under such circumstances, the flicker angle obtained in this flicker sensory test cannot be used as reliable material for determining the quality of the laminated glass plate.

The present invention solves the above-mentioned conventional problems, is consistent with the conventional evaluation method using the flicker sensory test method, and enables uniquely accurate evaluation of perspective distortion of laminated glass plates. The purpose is to provide an evaluation method.

[Means for Solving the Problems] The method for evaluating perspective distortion of a laminated glass plate of the present invention is for evaluating perspective distortion of a laminated glass plate formed by bonding two glass base plates with an interlayer interposed therebetween. The present invention is characterized in that the uneven shape of the outer surface of a laminated glass plate is measured, and the perspective distortion of the laminated glass plate is predicted from the surface uneven shape.

That is, the present invention utilizes the principle that the perspective distortion of a laminated glass plate is mainly caused by the refraction of light due to the unevenness of the surface of the glass base plate constituting the laminated glass plate.

An example of a method for implementing the present invention is a method using the following steps (1) to (2).

(2) Measuring the unevenness of the surface of a float glass plate continuously produced by a float-type plate making machine using an optical or stylus type surface unevenness needle.

■ From the measured unevenness of the surface of the glass plate, we performed ray tracing to determine the refraction of light on the surface using geometric optics calculations to detect the flickering or dynamic fluctuation pattern of the grid pattern on the screen seen through the laminated glass plate. Predict.

(2) The flicker angle of the target laminated glass plate is determined from the empirical formula that relates the characteristic parameters of the dynamic fluctuation pattern predicted in (2) and the flicker angle determined by the above-mentioned flicker sensory test.

According to the above steps ■ to ■, even if the method of the present invention is used,
Since the flicker angle can be determined in the same manner as before and there is no need to particularly change the conventional evaluation criteria, quality control is easy.

Below, the above procedures ① to ② will be explained in more detail.

(2) Measurement of unevenness on the surface of a glass plate The measurement of unevenness on the surface of a glass plate is usually carried out along the width direction of the glass plate. The measurement mode may be either cross-sectional measurement or roughness measurement, but cross-sectional measurement that represents the true surface shape is preferable.

■: Prediction of dynamic fluctuation pattern from the uneven shape From the uneven shape of the glass plate obtained in step (■), the refraction of light there is determined by geometric optics calculation. In this case, the laminated glass plate consists of an interlayer film and two glass plates with the interlayer film sandwiched between them, but since the refractive index of both is almost the same at the boundary between the interlayer film and the glass plate, this can be approximated as follows. Refraction of light at the interface can be ignored.

Therefore, the refraction at the boundary between the glass plate and the air is the main factor in the refraction of the laminated glass plate, so the refraction of light is determined from the uneven shape of the outer surface of the laminated glass plate. All you need to do is calculate. Therefore, in the following explanation, the refraction of light is calculated from the uneven shape of the outer surfaces of the two glass plates (two surfaces in total).

Once the refraction of light by the laminated glass plate is determined in this way, the movement of the lattice pattern when the measurer views the lattice pattern on the screen through the laminated glass plate can be calculated from this refractive index. The movement of this lattice pattern (dynamic variation pattern) appears as flicker, or perspective distortion, to the eyes of the measurer.

■ = Calculation of flicker angle An experimental formula that relates the characteristic parameters of the movement of the above-mentioned checkered pattern, that is, the dynamic fluctuation pattern, and the flicker angle determined by the conventional flicker sensory test is determined in advance, and this empirical formula is used to calculate the flicker angle. The flicker angle is calculated by substituting the characteristic parameters of the dynamic fluctuation pattern obtained in step (2). Thereby, the flicker angle of the laminated glass plate can be calculated by simply measuring the surface shape of the glass plate.

An empirical formula relating the characteristic parameter of this dynamic fluctuation pattern to the flicker angle can be obtained as follows.

In areas where the perspective distortion of the laminated glass plate is large, the lattice pattern moves greatly and quickly, as shown by arrows X in FIG. (Figure 1 shows the flickering of the grid pattern of the screen, that is, the dynamic This is a graph showing the fluctuation pattern. The horizontal axis shows the position of the laminated glass plate, and the vertical axis shows the vertical movement of the grid pattern at that position (unit: mm).
) is shown. ) Therefore, if the maximum amplitude, which is a characteristic parameter of this movement, that is, the dynamic fluctuation pattern, is AO, and the gradient of change at the maximum amplitude is BO (BO=AO/Co, see Fig. 1 for Co), then Q=A1. ×B
'', where m and n are constants and 1
≦m/n<4 is suitable. Then, for samples of laminated glass plates with various levels of perspective distortion, we correlated this Q with the flicker angle determined by the conventional flicker sensory test,
Find an empirical formula that expresses that relationship. As in the Examples described below, it was found that the value obtained from this experimental formula corresponded well to the actually measured flicker angle.

[Operation] The perspective distortion of a laminated glass plate is mainly caused by the refraction of light due to the unevenness of the surface of the glass plate that constitutes the laminated glass plate.

Therefore, by the method of the present invention, by measuring the uneven shape of the surface of two glass plates, the refraction of light can be calculated from this uneven shape, and the perspective distortion of the laminated glass plate can be easily calculated from the refraction of light. Moreover, it becomes possible to predict it uniquely and quantitatively.

In particular, by finding an empirical formula that relates the perspective distortion obtained by the method of the present invention and the flicker angle obtained by the conventional flicker sensory test, and substituting the characteristic parameters of the obtained dynamic fluctuation pattern into this, The flicker angle can be determined from the uneven shape of the surface.

[Example] Examples of the present invention are shown below.

Example 1 Regarding a float glass plate that is a material for laminated glass,
The uneven shape of the plate surface was measured using a stylus type surface unevenness meter. FIG. 2 shows the results and shows the uneven shape of the surface of the glass plate.

The horizontal axis in FIG. 2 indicates the position of the glass plate, and the vertical axis indicates an enlarged view of its unevenness. Further, the shaded area indicates the float glass plate section. That is, FIG. 2 shows the cross-sectional shape of the surface of the float glass plate.

Furthermore, the surface irregularities of the float glass plate that was the counterpart of this float glass plate were also measured in the same manner. The results are shown in FIG.

Figure 4 shows the movement of the lattice pattern on the screen obtained by refraction of light from these two surface irregularities.
=A/C-0,23), m= of Q; AMaXBI''
1.0. When n=0.5, Q = AI·OX B 0.5 w3.8”xo, 23°·5 =1.82 is calculated.

On the other hand, the relationship between the flicker angle (F) determined in advance and Q is as shown in FIG.

From FIG. 5, an experimental formula 9 expressing the relationship between F and Q was obtained. From this experimental formula, the flicker angle of the laminated glass plate, ie, the value of F in the case of Q-1, 82, was determined to be F-31° in this example. (In the conventional flicker sensory test method, it was 32 degrees.) In the same way, the flicker angle of a laminated glass plate was determined from the surface irregularities of a large number of glass plates. , shown in Table 1. From Table 1,
There is only a deviation of less than 1° between the flicker angle obtained by the conventional method and the flicker angle obtained by the method according to the present invention.
It is clear that the method of the present invention is a highly accurate evaluation method that can replace the conventional method.

Table 1 [Effects of the Invention] As detailed above, according to the method for evaluating perspective distortion of a laminated glass plate of the present invention, the perspective distortion of a laminated glass plate can be evaluated uniquely and accurately, mechanically, and It is possible to do this automatically.

That is, since the evaluation method according to the present invention can be carried out using a wiping cloth, evaluation errors due to individual differences among the measurers, as seen in conventional flicker sensory tests, do not occur at all. Therefore, the quality of the laminated glass plate can be evaluated more reliably since the evaluation is always performed using a constant standard.

Moreover, since the evaluation method according to the present invention can be consistent with conventional flicker sensory tests in its evaluation value (flicker angle), it can meet the standards for the quality of laminated glass sheets that have been accumulated from the past. There's no need to change.

[Brief explanation of the drawing]

Fig. 1 shows the movement of the grid pattern on the screen (dynamic fluctuation pattern) obtained by the evaluation method of the present invention, and Fig. 2 shows the cross-sectional shape of one surface of the laminated glass plate in Example 1. Figure 3 is a diagram showing the cross-sectional shape of the other surface of the laminated glass plate in Figure 2, and Figure 4 is a diagram showing the cross-sectional shape of the other surface of the laminated glass plate in Figures 2 and 3. A diagram showing the movement of the grid pattern on the screen (dynamic fluctuation pattern) obtained by the evaluation method, Figure 5 is a diagram showing the relationship between flicker angle and Q, and Figure 6 is the diagram used in the conventional flicker sensory test. FIG. 7 is an explanatory diagram of the flicker sensory test method. 1...Screen, 2...Sample stand, 3...Measuring person.

Claims (1)

[Claims] (1) When evaluating the perspective distortion of a laminated glass plate made by bonding two glass plates with an interlayer interposed, the unevenness of the outer surface of the laminated glass plate is measured, and the unevenness of the surface is used to A method for evaluating perspective distortion of laminated glass plates, which is characterized by predicting perspective distortion of glass plates.