JPS5930212B2 - Measuring device for image clarity of painted film - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an apparatus for measuring the sharpness of a paint film image.

Image sharpness (DOI) is the sharpness of the outline of the specular image reflected from the surface of the film (Sharpn-Ess).
is defined as

The DOI of the vane film is believed to have great aesthetic significance, particularly with respect to the overall appearance of the automotive finish. The measurement of the DOI was by projecting feature patterns of various sizes, such as partially cut rings known as Landolt rings, onto the painted surface to be evaluated. A rating scale is obtained by giving a value of 100 to the smallest set of rings and giving progressively smaller values to uniformly progressively larger rings. Using this method, the image of a ring reflected on a paint film is observed at a specific distance, and the film has a number of DOI values corresponding to the smallest set of rings that can identify a partial defect in the ring. Selected. This method has the disadvantage of being highly dependent on the visual accuracy of the observer and therefore requiring an additional step of averaging the readings of several observers to obtain an accurate value. are doing.

For obvious practical reasons, a method of automatically averaging observers is needed.

This eliminates interobserver differences and thereby eliminates the additional steps required by the American method. According to the present invention, an apparatus is provided for measuring the image sharpness of a sample painted film by comparison with a plurality of standard paint films having known DOIs. The device is at least partially hollow and includes a first opening for the sample display and a first opening on the hollow portion thereof extending vertically through both the upper and lower surfaces of the base. a base having a second opening in its upper surface proximate to the base; a portion thereof having at least one or more openings resting on the base and having two openings therein; a casing having a light source fixed within the casing over an opening in the base, moved into the hollow part of the base for displaying a series of standard veiling films through a second opening in the base; a casing for providing an imageable pattern that can be projected by the light source through the aperture in the base and onto the sample and the standard between the light source and the aperture in the base; image means within,
It includes.

The apparatus is designed to disperse a sample paint film to be evaluated below a first opening in the base.

A pattern forming an image is simultaneously projected onto the specimen and onto one of the standards displayed below the second aperture. The comparison thus greatly reduces the importance of the observer's visual accuracy. This is because all visual defects affect the appearance of both films equally. This device concerns the appearance of the sample relative to a standard of known value, rather than the appearance of the sample on an absolute scale. In conjunction with the accompanying drawings, FIG. 1 is a partially cutaway perspective view of the device in its upright position.

FIG. 2 is a top view of the base of the device with the casing removed. FIG. 3 is a front cross-sectional view of an assemblage with an imageable pattern. FIG. 4 shows an arrangement of Landol rings that can be used in an imageable pattern. ζ This device is hollow between its upper and lower surfaces.
It includes a generally flat base 1.

The base 1 has a rectangular first opening 9 (through which the sample to be evaluated is displayed and which extends perpendicularly through both surfaces) and a rectangular second opening 10 (
) on the upper surface. Openings 9 and 10 are adjacent on the upper surface as shown. A turntable 2 having a plurality of holes 11 having the same size and shape as the opening 9 is rotatably placed in the hollow portion of the base 1 .

The outer edge 3 of the turntable 2 projects through a slot in the side of the base 1 as shown to enable the turntable to rotate. each hole 11
Adjacent to the turntable 2 are radially outwardly placed standards (of known DOI values) each having a different DOI value.
Standard) Paint film 12 is attached.
The hole 11 hexagram and the standard 12 are located on the turntable 2 such that when the turntable 2 is rotated, the hole and the standard pass simultaneously and in vertical alignment with the opening 9 hexagram and the opening 10, respectively. ing. Each standard is a substrate coated with a paint film that may be comparable to the bait film to be evaluated in terms of chemistry and color.

It is not necessary for the invention that the chemistries and colors be similar in that two films with different chemistries or colors but with the same DOI value will reflect images of the same annular sharpness. . The substrate can be any paint-coatable material such as gold ply, cardboard, wood or fiberglass sheet, but gold ply substrates are preferred.

The substrate can be coated in a conventional manner and the DOI of the paint film can be measured. The standard used can have a DOI value that can fall anywhere from 0 to 100 depending on the nature of the veint film to be evaluated.

As an illustrative example, automotive finishes typically have DOI values between 70 and 100, so that if, for example, a 6-sheet standard is used for DOI measurements of that automotive finish, those values would be It can be 70, 80, 85, 90, 95 trigrams and 100. The present invention also contemplates other means for providing and projecting imageable patterns.

For example, the assembly 8 may have a diffuser plate 13 directly below the fluorescent lamp 7 and an imageable pattern formed in the apertures 9 and 1.
This can be excluded if it is directly printed on the surface of the scattering plate 13 facing 0. Although the apparatus of the present invention is believed to be generally applicable to measuring DOI, it is particularly useful for evaluating automotive films.

Therefore, for convenience of explanation, the operation of this device will be described in that sense. If an automotive finish DOI measurement is desired, the base of the device of the invention can be placed directly on the painted surface (sample) to be evaluated, such as the hood or trunk. The device may have a handle attached to the outside of the casing 5 to facilitate portability. The sample is displayed through opening 9 to an observer observing through gap 4. The turntable 2 is positioned so that the standard 12 is sampled under an opening 10 adjacent to the opening 9 under which the sample is visible.

Fluorescent lamp 7 simultaneously projects an imageable pattern onto the specimen and standard through apertures 9 and 10, respectively. The image reflected by the film is observed and the turntable 2 is rotated until a standard 12 appears below the aperture 10 that matches the sample with respect to the sharpness of the contours of the reflected image. Standard DO matched to sample DOI
A value equal to I is chosen. In addition to the described turntable, the apparatus of the invention includes any such means for displaying a standard bait film placed in parallel with the sample.

For example, instead of being placed on a turntable, a series of standards may be placed in a straight line on a long narrow panel and slid into a hollow part of the base along a groove or track.
It can be mounted if possible. The panel is positioned such that when the panel is moved along its longitudinal axis, different standards pass individually in vertical alignment with the apertures 10.

[Brief explanation of the drawing]

In the accompanying drawings, FIG. 1 is a partially cutaway perspective view of the device in its upright position, FIG. 2 is a top view of the base of the device with the casing removed, and FIG. 3 is a perspective view of the device in its upright position; FIG. 1 is a front cross-sectional view of an assemblage having a sexual pattern,
FIG. 4 shows the arrangement of Landol rings used in the imageable pattern.

Claims (1)

Claims: 1. A first aperture for a sample display which is at least partially hollow and extends vertically through both the upper and lower surfaces of the base and proximate the first aperture. a base having a second opening in its upper surface; a casing resting on said base having an observation hole therein and covering a portion having at least two openings; a light source fixed within a casing above the opening of the base, for displaying a plurality of standard paint films through a second opening of the base movably mounted within the hollow portion of the base; display means for providing an imageable pattern that can be projected by the light source onto a sample and standard through an aperture in the base located between the light source and the aperture in the base; Apparatus for determining the image sharpness of a sample paint film by providing a comparison with a plurality of standard paint films containing an imaging means in a casing. 2. The image forming means is sandwiched between a diffusion plate placed parallel to the base, a transparent panel below and parallel to the diffusion plate, and the scattering plate and the transparent panel. 2. The apparatus of claim 1, comprising a transparency having a sexual pattern. 3. said display means is a turntable rotatably mounted within a hollow portion of said base, said turntable allowing said turntable to rotate each standard without disturbing a first opening therein; 2. The apparatus of claim 1, having a standard paint film disposed thereon for display through the second opening of the apparatus. 4. said display means is a slip panel slidably mounted within a hollow portion of said base, said slip panel being capable of displaying each standard through a second opening in said base when it is slid; Apparatus according to claim 1, having a standard paint film placed thereon for leveling. 5 a first opening for a sample display that is at least partially hollow and extends vertically through both the upper and lower surfaces of said base; and a first opening in the upper surface adjacent to said first opening; a base having two openings; a casing placed on said base and having an observation hole therein and covering a portion having at least two openings; and a light source fixed above the aperture of the base, the light source being mounted within the hollow part of the base and rotating the turntable without disturbing the first aperture therein. a turntable resting in the casing below the light source and parallel to the base, with a standard paint film placed thereon to enable display of each standard through a second opening; A transparency carrying a diffuser plate, a transparent panel below and parallel to the diffuser plate, and an imageable pattern sandwiched between the scatterer plate and the transparent panel. a plate and the transparent panel are positioned such that an imageable pattern can be projected by the light source onto the sample and standards through openings in the base. An apparatus for measuring the image sharpness of a sample paint film by giving.