JP2017026424A - Method for evaluating background reflection on glass - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for evaluating a background reflection on a glass which is capable of properly evaluating a background reflection state to a glass by visual inspection.SOLUTION: A method is configured to evaluate by visual inspection a background reflection state in which a background reflection panel 4 arranged in a first space S1 is reflected on a glass 3, when a second space S2 is viewed from the first space S1 through the glass 3 for partitioning the first space S1 and the second space S2. The method for evaluating a background reflection is configured to create an evaluation environment in which a color difference ΔE calculated based on a lightness index Land chromaticness indexes a, bmeasured in accordance with a colorimetric system (L, a, b) regulated in a CIE 1976 colorimetric system becomes ΔE≥6, with respect to a background reflection image 31 in which the background reflection panel 4 is reflected and a background image 32 which is a background of the background reflection image 31 in the glass 3, when the second space S2 is viewed through the glass 3 from the first space S1, then evaluate the background reflection state by visual inspection in the created evaluation environment.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a method for evaluating reflection on glass, which is suitable for visual evaluation of a state reflected on glass.

  Conventionally, for example, it is generally known that an interior material such as an instrument panel is reflected on a windshield of an automobile. This type of reflection may cause the driver to feel uncomfortable or uncomfortable. For this reason, in order to suppress excessive reflection, it is important to visually evaluate the reflection state.

  For example, Patent Document 1 discloses a method for evaluating the reflection of an instrument panel on a windshield for an automobile, in which a difference in brightness or brightness between a concave portion and a convex portion constituting a texture on the surface of the instrument panel reflected on the windshield. Based on this, a reflection evaluation method for evaluating the reflection state of the instrument panel on the windshield has been proposed.

JP 2014-084071 A

  However, according to the technique of Patent Document 1, the reflection state is evaluated based on the luminance difference or brightness difference in the reflected image in which the reflection member such as the instrument panel is reflected among the glass such as the windshield. For this reason, there may be variations in the visual evaluation of the reflection state. This is because not only the reflected image but also the state of the non-reflected portion (background image) deviated from the reflected image has a great influence on the visual evaluation of the reflected state.

  In consideration of such points, the evaluation of the reflection state is made by setting a standard for the luminance difference or brightness difference between the reflection image reflected in the reflection member of the glass and the background image outside the reflection image. Can also be considered.

  However, the luminance difference and the lightness difference are optical indices that quantify only the lightness and darkness of light that the human eye feels. For this reason, even if a standard is set for the luminance difference or brightness difference and the reflection state is evaluated visually under the environment of this reference, the reflection is weak depending on the color combination of the reflection image and the background image (reflection In some cases, the reflection state on the glass cannot be properly confirmed by evaluation.

  This invention is made | formed in view of the said subject, The place made into the objective is to provide the reflection evaluation method to glass which can evaluate the reflection state to glass appropriately by visual observation. is there.

In view of the above problems, the method for evaluating reflection in glass according to the present invention provides the first space when the second space is viewed from the first space through the glass partitioning the first space and the second space. A reflection evaluation method for glass, in which a reflection state in which a reflection member arranged in a space is reflected in the glass is visually evaluated, wherein the second space is viewed from the first space through the glass. A color system (L ^* , a ^* , C ^*) defined in the CIE 1976 color system for a reflected image reflected by the reflected member and a background image as a background of the reflected image. b ^* ), an evaluation environment in which the color difference ΔE calculated from the lightness index L ^* and the chromaticness index a ^* , b ^* measured in accordance with b ^* ) is ΔE ≧ 6 is created. It is necessary to visually evaluate the reflection state. And butterflies.

  According to the present invention, in the evaluation environment in which the color difference ΔE between the reflected image reflected on the glass and the background image serving as the background satisfies ΔE ≧ 6, the degree of reflection on the glass is large (the reflection is strong). High correlation with visual reflection state. For this reason, under such an evaluation environment, the state of reflection on the glass can be more appropriately evaluated by visual observation.

(A) is a figure for demonstrating the calculation of the color difference (DELTA) E in the reflection evaluation method to the glass which concerns on embodiment of this invention, and the method of creating the conditions of color difference (DELTA) E> = 6, (b), It is the figure which showed the state of the reflection on the glass shown to (a), (c) is for demonstrating the visual evaluation of the reflection state to glass, after creating the conditions of color difference (DELTA) E> = 6. FIG. (A) is a figure for demonstrating the confirmation test for confirming the correlation with color difference (DELTA) E in the reflection evaluation method to the glass which concerns on embodiment of this invention, and visual sensory evaluation result, (b) (A) is the figure which showed the state of the reflection to the glass shown to (a), (c) is a figure for demonstrating the measuring method of color difference (DELTA) E. It is the figure which showed the evaluation sheet | seat of visual sensory evaluation shown to Fig.2 (a). (A) is a graph showing an example of the relationship between the color difference ΔE and the visual sensory evaluation result, (b) is a graph showing an example of the relationship between the luminance difference ΔY and the visual sensory evaluation result, c) is a graph showing an example of the relationship between the brightness difference ΔL ^* and the visual sensory evaluation result. And the maximum color difference Delta] E, is a graph showing the relationship between the correlation coefficient R ² of the visual.

  Below, the reflection evaluation method to the glass which concerns on embodiment of this invention is demonstrated, referring Fig.1 (a)-(c).

  FIG. 1A is a diagram for explaining the calculation of the color difference ΔE and the method of creating the condition of the color difference ΔE ≧ 6 in the reflection evaluation method for the glass 3 according to the embodiment of the present invention. FIG. 1B is a diagram showing the state of reflection on the glass 3 shown in FIG. 1A, and FIG. 1C shows the condition of the color difference ΔE ≧ 6 and then the glass 3 It is a figure for demonstrating the visual evaluation of a reflection state.

  In the present embodiment, as an example, evaluation of the reflection state on the glass assuming the reflection of the instrument panel on the windshield of the vehicle is performed. As shown in FIG. 1A, first, assuming a vehicle windshield, a predetermined reflectivity is set so as to partition a first space S1 that is regarded as an interior space and a second space S2 that is regarded as an exterior space. The held glass 3 is inclined and arranged. In the first space S1 partitioned by the glass 3, a reflection panel (reflection member) 4 that assumes an instrument panel of the vehicle is arranged.

  More specifically, the glass 3 and the reflection panel 4 are arranged so that the reflection panel 4 is reflected on the glass 3 when the second space S2 is viewed from the first space S1 through the glass 3. . On the other hand, in the second space S <b> 2 assuming the outside of the vehicle, the background panel 5 that looks like the scenery in front of the vehicle is disposed, and the light source 7 is irradiated from above the glass 3.

  In this state, when the glass 3 is viewed from the observation position where the spectral radiance meter 6 shown in FIG. 1A is arranged, the reflection panel is formed on the glass 3 as shown in FIG. There is a reflected image 31 in which 4 is reflected, and a background image 32 in which the background panel 5 can be seen exists in other portions. In other words, the background image 32 is an image corresponding to the background panel 5 seen through the glass 3, and the reflection image 31 is an image in which the reflection panel 4 is further reflected.

In this state, in the spectral radiance meter 6 arranged at the observation position in the first space S1, a reflection image 31 in which the reflection panel 4 is reflected in the glass 3 and a background image deviated from the reflection image 31 are displayed. 32, the lightness index L ^* and the chromaticness index a ^* , b ^* conforming to the color system (L ^* , a ^* , b ^* ) defined in the CIE 1976 color system are measured.

Next, the color difference ΔE is calculated from the brightness index L1 ^* and chromaticness index a1 ^* and b1 ^{* of} the reflected image 31 and the brightness index L2 ^* and chromaticness index a2 ^* and b2 ^{* of} the background image 32. .

Specifically, the color difference ΔE can be calculated from the following equation.
^{ΔE = [(L1-L2)} 2 + (a1 * -a2 *) 2 + (b1 * -b2 *) 2] 1/2

  Here, as apparent from the confirmation test described later, when the color difference ΔE is ΔE <6, the correlation between the color difference ΔE and the visual reflection evaluation result (visual sensory evaluation result) is low. . That is, under this condition, as shown in FIG. 1C, even when the reflection state is visually evaluated, the difference in color and brightness between the reflection image 31 and the background image 32 is small. It is difficult to appropriately visually evaluate the state of reflection on 3.

  Therefore, in the present embodiment, when the calculated color difference ΔE is ΔE <6, an evaluation environment in which the color difference ΔE satisfies ΔE ≧ 6 is expected. Specifically, the reflectance of the glass 3, the inclination angle of the glass 3, the color (color and brightness) of the background panel 5, the color (color and brightness) of the reflection panel 4, and the light amount (light intensity) of the light source 7 Or at least one condition selected from the group of colors to be generated) to create an evaluation environment in which the color difference ΔE is ΔE ≧ 6.

  In this built-in evaluation environment (environment where the color difference ΔE ≧ 6), as shown in FIG. 1C, the reflection state of the reflection panel 4 on the glass 3 is visually evaluated. In the present embodiment, in an evaluation environment where the color difference ΔE satisfies ΔE ≧ 6, the difference in color and brightness between the reflected image 31 and the background image 32 is large, so the degree of reflection on the glass is large, and the actual reflection occurs. There is a high correlation between the state of the light that appears and the reflected state visually. Thereby, in such an evaluation environment, the state of reflection on the glass 3 can be more appropriately evaluated by visual observation.

When the color difference ΔE ≧ 6 defined in the CIE 1976 color system is converted to the color difference ΔE00 defined in the CIE 2000 color system, ΔE00 ≧ 6 is obtained, and the color difference ΔE defined in the L ^* C ^* h color system is converted. Then, ΔE ≧ 6.

Therefore, “creating an evaluation environment in which the color difference ΔE ≧ 6” in the CIE 1976 color system referred to in the present invention is equivalent to “creating an evaluation environment in which the color difference ΔE00 ≧ 6” in the CIE 2000 color system. Yes, in the L ^* C ^* h color system, it is equivalent to “make an evaluation environment where the color difference ΔE ≧ 6”.

In this evaluation method, the background panel 5 and the light source 7 may be omitted as long as the evaluation can be performed under the background environment and brightness environment to be evaluated. If the brightness index L ^* and chromaticness index a ^* , b ^* between the reflected image 31 and the background image 32 can be measured, an imaging device such as a camera can be used instead of the spectral radiance meter 6. May be used.

  Moreover, you may apply this reflection evaluation method to glass to a vehicle. That is, in a vehicle such as an automobile, the glass 3 is a vehicle glass such as a front glass, the reflection panel 4 is an interior material such as an instrument panel, the first space S1 is an interior space, and the second space is an exterior space. Evaluate the reflection of interior materials on glass.

  However, like this embodiment, before applying this evaluation method to a vehicle and evaluating it, using the apparatus configuration shown in FIG. It is possible to easily and quickly predict the evaluation of the reflection state of the interior material on the vehicle glass under various environments.

(Confirmation test)
In the following confirmation test, the appropriate range of the color difference ΔE in the method for evaluating reflection in glass according to the embodiment of the present invention was confirmed.

  Specifically, 10 male and female subjects in their 20s to 50s (male: 58 years old, 56 years old, 52 years old, 45 years old, 40 years old, 31 years old, female: 55 years old, 36 years old, 26 years old, 25 years old The visual sensory evaluation shown below was performed, and the appropriate range of the color difference ΔE in the reflection evaluation method was confirmed.

  In this confirmation test, as shown in FIG. 2 (a), two different reflection panels 4L and 4R are arranged side by side as shown in FIG. Visual sensory evaluation of 4R reflection state was performed.

First, as shown to Fig.2 (a), as glass 3A which partitions 1st space S1 and 2nd space S2, three types of glass plates with a reflectance of 12.3%, 8.7%, and 8.2% are used. Prepared. As the reflection panels 4L and 4R, five types of panels of gray, red, green, yellow and blue colors having a lightness index L ^* = 50 were prepared.

As the background panel 5A shown in FIG. 2A, five types of panels were prepared: a black panel having a lightness index L ^* = 0 and a gray, red, green, and blue panel having a lightness index L ^* = 40. A D65 light source was prepared as the light source 7A.

  Next, the glass 3A and the background panel 5A are selected at the levels (1) to (9) shown in Table 1 below. As shown in FIG. 2A, the glass 3A, the background panel 5A, and the light source 7A are selected. Arranged. For each level, two different reflection panels were selected from the five types of reflection panels described above so as to be left and right to be the round robin, and the two selected reflection panels 4L and 4R were arranged on the left and right. The angle between the reflection panels 4L and 4R and the glass 3A is 30 °.

  Here, as shown in FIG. 2B, the left and right reflection images are reflected with respect to the left and right reflection images 31L and 31R reflected on the glass 3A by the selected left and right reflection panels 4L and 4R. The visual sensory evaluation was performed for each of the 10 subjects described above using the evaluation sheet shown in FIG. 3 with respect to the combination of colors of different reflection panels in order to quantify how much the noise is.

  For example, in the evaluation sheet shown in FIG. 3, when a glass plate having a glass reflectance of 12.3% is used as the glass 3A and a black panel is used as the background panel 5A so as to satisfy the level of (1) in Table 1. The evaluation results are shown. For example, in the case of the uppermost stage shown in FIG. 3, a gray panel is used for the left reflection panel (left panel) 4L, and a blue panel is used for the right reflection panel (right panel) 4R.

  Here, in the case of the uppermost stage shown in FIG. 3, the larger the reflection of the left panel (gray) with respect to the right panel (blue), the larger the value of “−” is checked, and vice versa. ), The larger the reflection on the right panel (blue), the larger the value of “+” is checked. If the left panel (gray) and the right panel (blue) are the same, the value of “0” is checked.

  In the uppermost stage shown in FIG. 3, since the value of “−2” is checked, the subject evaluates that the reflection of the left panel (gray) is slightly larger than the right panel (blue). Such visual sensory evaluation was performed for all combinations of the left and right reflection panels 4L and 4R for each of the levels (1) to (9). Table 2 summarizes the results of the evaluation sheet shown in FIG. 3, and shows the results of visual sensory evaluation at the level of (1) in Table 1 of the subject (female: 25 years old).

  Here, as shown in Table 2, the column total and the row total of the table obtained for each subject are calculated, and a value obtained by subtracting the row total from the column total (column total−row total) is calculated. The average value of subjects for each color (column total-row total) is calculated, and this average value is divided by 10 (2 × number of panels (5)). Thereby, the value (index of the vertical axis | shaft of FIG. 4A) of the visual sensory evaluation result according to the kind of color of each reflection panel can be obtained for every level of (1)-(9).

  Next, as shown in FIG. 2C, the reflected image reflected on the glass when the five types of reflected panels are arranged for each level of (1) to (9) and the background image as the background. The color difference ΔE was calculated. Table 1 shows the maximum color difference ΔE that is the maximum of the color difference ΔE among the calculated color differences ΔE for each level of (1) to (9).

  Next, for each level of (1) to (9), as shown in FIG. 4 (a), the value of the visual sensory evaluation result corresponding to the type of color of each reflection panel is taken as the vertical axis, and each reflection is shown. A graph was created with the horizontal axis representing the color difference ΔE measured according to the type of panel color.

  From the created graph, the correlation coefficient between the value of the visual sensory evaluation result and the color difference ΔE was calculated by the least square method using the linear function as the correlation function. Table 1 shows the results of the correlation coefficients at the levels (1) to (9). FIG. 4A is a diagram showing an example of the relationship between the color difference ΔE and the visual sensory evaluation result, and is a graph corresponding to the level of (1).

On the other hand, for each level of (1) to (9), the brightness difference ΔY and brightness difference ΔL ^* between the reflected image reflected on the glass when five types of reflected panels are arranged and the background image as the background ^. A graph was created with the value of the visual sensory evaluation result corresponding to the type of color of each reflection panel as the vertical axis and the luminance difference ΔY or the brightness difference ΔL ^* as the horizontal axis (FIG. 4 (b) and (See (c)).

A correlation coefficient between the value of the visual sensory evaluation result and the luminance difference ΔY or the brightness difference ΔL ^* was calculated from the created graph by a least square method using a linear function as a correlation function. FIG. 4B is a diagram showing an example of the relationship between the luminance difference ΔY and the visual sensory evaluation result, and FIG. 4C is a diagram showing an example of the relationship between the brightness difference ΔL ^* and the visual sensory evaluation result. It is. FIGS. 4B and 4C are graphs of the level at which the correlation coefficient is maximum among the levels of (1) to (9).

  When comparing FIGS. 4A to 4C, the parameter having the highest correlation with the value of the visual sensory evaluation result is the color difference ΔE shown in FIG. This is presumably because the visual sensory evaluation includes not only the brightness of the reflected image and the background image but also the influence of these colors.

  Then, as shown in FIG. 5, a graph was created from Table 1 with the vertical axis representing the correlation coefficient with visual observations at the levels (1) to (9) and the horizontal axis representing the maximum color difference ΔE. From this result, if the maximum color difference ΔE ≧ 6, the value of the visual correlation coefficient is large, and if the evaluation environment is created so as to satisfy the condition of the color difference ΔE ≧ 6, the reflection panel is reflected on the glass. It is considered that the reflection state can be appropriately evaluated visually.

  Although the embodiment of the present invention has been described in detail above, the specific configuration is not limited to this embodiment, and even if there is a design change within a scope not departing from the gist of the present invention, they are not limited to this embodiment. It is included in the invention.

3, 3A: Glass, 4, 4L, 4R: Reflection panel (reflection member), 5, 5A: Background panel, 6: Spectral radiance meter, 7, 7A: Light source, 31: Reflection image, 32, 32A : Background image, S1: first space, S2: second space

Claims (1)

When the second space is viewed from the first space through the glass that partitions the first space and the second space, a reflection state in which the reflection member disposed in the first space is reflected on the glass is illustrated. An evaluation method for reflection on glass, which is evaluated by visual observation,
When the second space is viewed from the first space through the glass, the CIE 1976 color specification is applied to the reflected image reflected by the reflecting member and the background image serving as the background of the reflected image. The color difference ΔE calculated from the lightness index L ^* and chromaticness index a ^* , b ^* measured in accordance with the color system (L ^* , a ^* , b ^* ) defined for the system is ΔE ≧ 6 Create an evaluation environment,
A method for evaluating reflection in glass, characterized in that the reflection state is visually evaluated in the built-in evaluation environment.

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