DE2101818A1 - Colorimeter - Google Patents

Description

THE RESEARCH ASSOCIATION OF BRITISH PAINT, COiOUR & VARNISH MANUFACTURERS Teddington, Middlesex (Great Britain)

Colorimeter

The invention relates to a measuring device for colors known as a colorimeter.

The measurement of colors in objective color values depends

on the visual comparison determination of the color to be measured with a combination of defined light stimuli. To create an international standard, the Commission Internationale de L'Eelairage (G, I »E.) Has a Standard color measurement system set up based on cien spectral

Sensitivity

curves to which a "normal observer" responds, whereby three primary light sources X, Y and Z are used, which are defined as light of a given wavelength,

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. Each color can be precisely defined in terms of the quantity of these three light stimuli that are required to produce a To match the color. The color can also be defined by values of other functions, such as L, a, and b will.

The spectral curves for the normal observer's response to the three primary light stimuli are well known, and it is necessary that the spectral sensitivity of any photoelectric colorimeter should reproduce these three response curves as closely as possible so that accurate values of X, Y and Z can be determined for each color. The spectral response of the colorimeter depends on the energy distribution of the light source, the spectral transmission of the filter or other optical elements and the response of the detector. Various attempts have been made to design colorimeters with the correct response curves, using combinations of filters in the light path, which in turn correspond to the three response values η. Usually only an approximate agreement is achieved, partly because the selection of the filters is based on average values for the light sources and detectors based and partly because a large number more subtractive

Filters are used to find a usable match to achieve, whereby the amount of light that passes through the filter and reaches the detector is of the order of magnitude

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is lower and the colorimeter is not very sensitive.

It is therefore the aim of the invention to create a colorimeter which allows a relatively precise adaptation to the standardized response curves enables.

The inventive colorimeter, the g is a lighting device for a sample whose color is to v measured / ground and having in the light path is switched filter is erfindungogeniäss characterized in that it comprises a number of light guides which extend between a light detector and a scanning head , which can be set so that the ends of the light guides receive light from the sample, with at least one and preferably most or all of the light guides in the light path having a single correction filter, so that the light received by the detector from at least one of the light guides has the individual correction filter , the ™

is assigned to this light guide, and the values measured at the detector output pass through the values X, Y or Z of the normal observer as defined by the Commission Internationale de L'Eclairage or another Function.

k ".i output of the detector results in values measured in advance of certain fillers or filter sticks

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BATH ORIGINAL

the values X, Y and Z. By changing the filter set or the filter set that is connected to the light guide, the other two values can be measured, whereby the colorimeter according to the invention can be used to precisely identify a certain color. By means of a suitable filter selection, the output values of the detector can, for example, be representative of the values L, a and b or the values X, Y and Z can be electrically converted into the values. L, a and b are converted .

YIeIl each light guide or most of the light guides can be equipped with its own correction filter and the light from all these light guides is combined before the measurement - filters can be selected that modify the light according to the principle of additive mixing. The greater the number of light guides, the more filters can be used additively to adjust the response of the colorimeter to the Sen CI »Ε. Standard. In practice it is found that it is sufficient to use about 5 or 6 light guides, whereby one light guide or several or each light guide can be provided with its own corrosion filter. The addition of the individual light paths enables dfu-r-. a better Uboreinstiinnung nrit

the Kor-malbeobaehter genriss Cl, K. reached v.rrdeu J; r. ^v ;; i _s as

this usually by using a number of subtraU live r * Filter can be reached, from ^ o ^ dcrn can the LicüU ^ jü ^ o,

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BATH ORIGINAL

_ 5 -

received by the detector, be relatively large and thus the instrument can be very sensitive. Furthermore, each light guide can be fitted with a pair of correction filters be equipped, i.e. a filter at each end of the light guide, whereby these filters work subtractively, so that a more precise match is achieved.

Light detectors, even those of nominally matching type, can vary in terms of their spectral response from- (j differ from each other. With a colorimeter according to the invention it is possible to determine the response curves of each individual colorimeter directly and to use suitable correction filters with the light guides.

Since the light is collected from a number of directions through the light guides, the location of the light guides, with respect to the selected sample to be tested so that they are uniformly ä spaced of- arranged around the specimen each other, so that any differences in the reflection on average balanced by the sample.

According to the invention, in a further embodiment, a colorimeter is provided which has a device for illuminating a sample and a scanning head for the light from a series of directions which are similarly arranged around the sample a ^1st and pre

y 2 : ■■ ". ■ ■ - 6 -

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BATH ORIGINAL

■ directions between the scanning head and a light detector, which transmit the collected light to the detector, as well as one or more filters through which it can be extracted

or light collected in all directions passes before the collected light in the Dekektm; is entered so that fourth measured at the detector exit are arranged in such a way can that they are for one of the three primary light stimuli X, Y or Z of the normal observer according to the definition of the Commission Internationale de L'Eclairage or for a other function are representative.

According to the invention, it is desirable or preferred that Light from all light guides through a "diffuser" before it hits the detector in order to achieve a uniform light distribution. Also can it can sometimes be beneficial to have one or more subtractive Insert filters between the ends of the light guides and the light detector.

It can be seen that a colorimeter according to the invention enables a large selection of filters and their arrangement, whereby wieaerura a colorimeter is created that has a very large number of degrees of freedom. i. [a2i can thus use as many filters and light guides as are required in an individual case to achieve the in

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to achieve the required accuracy in this case, whereby the following applies: that with a larger number of degrees of freedom also one

better ones

Approach to the Koriaal observer according to the definition the Commission Internationale de L'Eclairage is achieved.

The Detektoi; can be a photocell or a photomultiplier.

Preferably, the light guides or light guide devices that extend between the scanning head and the light detector can be bundles of fiber optics. These have the advantage that they are flexible, losses of transmitted light are low and the ends of the bundles can be brought relatively close to the sample to be tested, which means that a relatively large angle of light reception can often take place on the sample, so that a relatively large large amount of light can be absorbed.

The test sample must be constant by a light source Brightness and spectral energy distribution are illuminated. This can usually be achieved satisfactorily by using an electric lamp will that of. a stabilized energy source spits. For example, the lamp can be operated in this way because they have a color temperature of 2354 ° A (i.e. C.I.K. ütsnöard-jieluchten A).

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ORIGINAL INSPECTED

When measuring colors and controlling color measurements with instruments, it is essential to select an instrument that will reproduce numerical values of color or color differences that match visual estimates as judged by experienced color comparators. In order to have a good correlation between the results of the visual measurement and the measurement by instruments, the exact matching representation of the C »IE functions does not succeed. The geometry of the lighting and viewing used by the observer in relation to the color measurement should be reproducible by the instrument. In 1931 the CIE recommended a 45 / O geometry as the norm for making measurements on opaque surfaces, and in 1967 four other arrangements were recommended. Depending on the surface properties of the sample to be examined, one geometry can be better than another. In conventional colorimeters, only one geometry is usually used, which is why these devices can only be used for color measurements with a limited number of substances. Using flexible light guides in the construction according to the invention, color measurements can be obtained for any desired geometry by using different scanning heads, the ends of the light guides being placed at appropriate viewing angles _and these heads can be easily and quickly exchanged. Also, a combination of more al;.; one geometry possible.

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A particularly advantageous way of illuminating the sample is the use of an additional light guide, for example a bundle of its fiber optics, extending from it an electric lamp extends to the particular scanning head used. The important advantages of this arrangement consist in the fact that the scanning head can be chosen so that

that it meets the special requirements of the sample being tested and does not need to be fixed because the light guides are flexible and therefore the scanning head can be far away from the light source and the light detector. These advantages can be evaluated by bringing the head up to the sample and not bringing the sample up to the head. This makes the colorimeter according to the invention particularly useful for use in controlling industrial processes. For example, the colorimeter for monitoring the color may be one approach, a paint used, for example, the paint having a suitable head viewed and the output from the detector values for similar control of the addition of dyes used to achieve a · desired color .A further example is the regulation of processes, for example anodizing, .. whereby a color change occurs. Here, the head can be used to scan the color of the product, and the values emitted by the detector can be used "to adjust the progress of the reaction and, given

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ti

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if stop at a certain point.

The instrument described above is a single chair colorimeter. It can easily be converted into an instrument known as a double beam instrument, where Light transmission devices are provided, which may lead directly from the lamp to the detector and not to the sample. Preferably, these devices consist in another bundle of fiber optics along with a shutter that allows the passage of light from the lamp either to the sample or directly to the detector. The advantage of a double-beam instrument is there in that this device can be calibrated from time to time to ensure that the lamp and the detectors remain constant with regard to the output values or the response.

In addition to its use as a colorimeter, the Device can be used as a spectrophotometer, with a monochromatic light source instead of the lamp, for example a monochromator is used and removed the various filters that are connected to the light guides or the devices between the scanning head and the light detector work together.

A colorimeter according to the invention is shown in the examples an embodiment with reference to the attached

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Drawings explained in more detail. In the drawings is

Figure 1 the schematic representation of the colorimeter,

FIG. 2 an enlarged detailed view of the detector head of the colorimeter,

FIG. 3 shows an enlarged perspective view of one form of a scanning head for the colorimeter,

Figure 4 is an axial section of the head shown in Figure 3,

FIG. 5 an enlarged section of another shape a scanning head,

FIG. 6 is a diagrammatic representation of another scanning head for use in color control in paint manufacture and - A

FIG. 7 is a block diagram illustrating one way of using the head of FIG.

The colorimeter 10 shown in the drawings has a scanning head 12 for viewing a sample 14 whose * Color to be measured. The construction more suitable

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Heads 12 will be explained below. Extend from head 12 six flexible light guides 16 to 21,. each consisting of a bundle of fiber optics. These Light guides extend to a detector head 22, the construction of which will also be explained in detail later

The detector head 22 is connected to a closed housing in which a photomultiplier 32 is located, " to pick up the light from the detector head. A light diffusion screen 33 is placed in front of the photomultiplier 32 to ensure that the sum of the light that through the light guides 16 to 21 arrives evenly is distributed over the sensitive surface of the photomultiplier.

The sample 14 is illuminated by a light guide 34 which consists of a bundle of fiber optics. One end of the guide receives light from an electric lamp 36, which is located in a closed housing 38, while the other end extends to the head 12 to illuminate the sample. In order to keep the lighting constant, the lamp 36 is fed by a stabilized energy source 44. For example, the lamp can be operated so that it emits light with a color temperature of 2854 ⁰ A (ie GIE standard lighting A).

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Individual filters 46 and 25 can be used at the end of one or more or all of the light guides 16 to 21 be attached to the scanning head of the light guides and to the detector head of the light guides. These filters are - however usually not required.

As can best be seen from Figure 2, the detector head consists of two coaxially attached cylinders 23 and 24, the inner cylinder 24 with respect to the outer cylinder _Λ

23 is rotatably arranged and can be rotated with respect to the outer cylinder 23 with the aid of a knob 24d. the Ends of the light guides 16 to 21 terminate at six symmetrically spaced-apart exits 23a of the outer cylinder 23, the outputs forming an angle of 45 to the axes of the two cylinders, so that the light collected by the six light guides 16 to 21 at an axially located point 33a on the light ■ diffusion screen 33 is collected. The inner cylinder

has four groups of six outputs 24a, which by two ^

peripheral rings are arranged around, the inner cylinder 24 sliding axially with respect to the outer cylinder is arranged to bring one or the other ring of the outputs 24a into alignment with the outputs 23a.

Some or all of the outputs 24a have a filter or a filter combination 26.

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Pie spectral transmissions of a filter arrangement or filter combination 26 are arranged so that taking into account the spectral sensitivity of the photomultiplier 32 and the spectral energy distribution of the lamp 36 and the spectral transmission of the light guides that The colorimeter as a whole has a sensitivity distribution that can be precisely adjusted so that it works with one the three primary light stimuli X, Y and Z of the normal observer according to the sensitivity distribution curves of the C.I.B. , for example, corresponds to a part of the X-light stimulus. By rotating the inner cylinder 24 and shifting it axially may have another set of outputs 24a with associated filters 26 in alignment with the outputs 23a, reducing the response of the instrument with the other parts of the X-light stimulus and the Light stimuli Y and Z are brought into agreement.

In some cases it may be desirable to place a subtractive filter 48 between the light diffusion screen 33 and the Switch on Photomultiplier '32. This filter could possibly be removed or replaced when the Measurement is changed from the measurement of one light stimulus to that of the other light stimulus.

The photomultiplier 32 is powered by a suitable power source 50 · fed, while its output power is in

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a digital voltmeter 52 'is fed in, which displays the results in a suitable manner, for example by means of a suitable counter. For smooth, flat, opaque surfaces, for example films of paints, plastics, ceramic tiles and opaque vitrolite glass, it has been found that a scanning head 12a according to FIGS. 3 and 4 is most suitable. This consists of a conically shaped capsule 50 with a hemispherical inner surface 51 which has an inner diameter of, for example, 3.5 cm (1 inch). | The light guide 34 for illumination is inserted into an opening 34a at the apex. The light guides 16 to 21 are inserted into openings 16a to 21a which are arranged symmetrically around the apex, the axes of which are inclined at an angle <k of 45 ° (FIG. 4) and intersect at the center of the sphere. This creates an illuminated circular area approximately 6.35 mm (1/4 inch) of sample 14 facing the opening. As can be seen, the light guides 16 to, 21 collect the light uniformly from the illuminated spot on the sample 14 ^: and around it, which compensates for the irregularities of the reflection.

A scanning head similar to the head 12a, as shown in Figures 3 and 4, but an inner hemispherical one 5.1 cm (2 in.) Inside diameter area and a

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12.7 now (1/2 inch) diameter area illuminated, was used as a for surfaces that have a texture

found even more suitable. This head has been tried on various samples of cotton fabrics and synthetic fiber yarn. Variations in the color measurements at different orientations of fabrics or yarn with respect to the scanning head, it was small. This is due to the integration of the light that is diffusely reflected by the material in six different directions. A greater number of the collector elements will give readings that are independent of orientation, such an arrangement being suitable for color measurements of fabrics with pronounced specular reflection, as is the case with some fabrics and synthetic fiber yarns.

In some cases, for example when staining through

For anodizing aluminum, the scanning head must be converted into the

The dye bath must be immersed at a distance from the aluminum surface to be observed so that it does not get the Interferes with the anodizing process. These conditions can be met by using the scanning head 12b according to FIG will. This consists of a circular disk about 15.3 cm (6 inches) in diameter with an axially im Center-made hole 54, which is surrounded by -holes 56-

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is given, the axes of which are inclined at an angle of 4 5 ° and intersect 12.7 cm (5 inches) from central hole 54. This head 12b with the light guides attached to it 34 and 16 to 21 can be used for color control in an anodizing process to determine the color change of a treated approach. When the output values from the voltmeter 52 show that the desired Color is reached, the anodizing process can be canceled will. The dye bath maintains an almost constant color during the anodizing process, so this factor -

does not affect the results.

When measuring the color of a liquid, it was found that there are various methods of using the present invention Colorimeters there. For example, a suitable scanning head can be encased in a plastic material envelope

which has a glass window that ends at the end a head 12a according to Figure 3 is attached. The head is then placed in the liquid in a suitable container immersed. The E window could also be a part in the wall of the liquid container.

However, it has been found that when measuring the color of a paint or other adhesive material, like a syrup, the preferred method consists in placing a suitable head 12c according to FIG

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Set up at a distance above the surface of the liquid, the color measured in this case being that of the interface between liquid and air. This process ensures that the paint at the interface changes continuously and is representative is for the bulk of the paint and not that Corresponds to the point that is contacted first and is attached to a transparent surface. This head 12c is ideally suited for monitoring the coloration in the production of paints and in batches Manufacturing than continuous manufacturing.

As shown in Figure 6, the scanning head 12c is connected to a simple device which has a constant Fill level allowed. The paint, its coloring

is to be measured, flows into an inlet tube 60 in a funnel 62 which is enclosed by a light-tight cylindrical container 64. The scanning head 12c of the colorimeter is attached to the top of the container either in alignment with an opening in the container or in alignment with a transparent open part of the container. The container has an outlet tube 66 at the base. The flowing paint fills the funnel and flows down to the outlet tube 66. Because the upper edge of the funnel forms a horizontal plane, a constant distance between the surface of the paint and the scanning head can be achieved

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be adhered to, which enables exactly the coloring of a wet paint at an interface between to measure the paint and air. The construction of the scanning head 12c can be similar to that of the head 12a, the distance between the head and the specimen is precisely maintained.

In order to determine the color of a specific sample 14, the scanning head 12 used in each case is brought up to the sample, and the light from the sample, which is of course illuminated by λ the lamp 36, passes through the various light guides and through a specific filter arrangement 26, depending on which arrangement of openings 24a is aligned with the openings 23a. The light from all light

guides is then recorded by the photomultiplier 32 and

the output power is registered on the voltmeter 52. By properly selecting filters 25, 46 and 48, if used, and the particular set of filters 26 that are aligned with the light guides, the output power displayed by the voltmeter gives a value that, for example, for a part of the light stimulus X. Then, by rotating the inner cylinder 24, whereby another group of openings 24a with the corresponding filter sets 26 is brought into alignment with the light guides, the instrument is set up so that it displays the fourth, which is representative of the other part

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of the light stimulus X and the light stimuli Y and Z are. In this way an exact and complete determination of the. ^:

Color of sample 14 can be obtained.

As can be seen, the colorimeter 10 according to the invention is relatively simple with regard to the arrangement and the mode of operation. It is also possible to select filters 26 and, if necessary, filters 25, 46 and 48 so that the colorimeter as a whole corresponds closely to the standard curves according to CIE for the sensitivity distribution s year. Each filter position results in an additional degree of freedom when adapting to the CIE standard observer, so that the number of light guides and the number of filters can be selected according to the desired accuracy. In practice, it is found that the six light guides with a suitable filter and possibly also a filter 46 are sufficient, although more or fewer light guides may be necessary in certain cases.

Since individual photomultiplier 32 with regard to their response can be different, the filters can be selected to suit a particular photomultiplier are so that the response of every single colorimeter can be set so that it comes close to the behavior of the normal observer.

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Since the photo multiplier takes up the sum of the light, that goes through all light guides can be done by the colorimeter be more sensitive than a colorimeter where the desired spectral sensitivity distribution-thereby what is achieved is that the light only passes through a series of subtractive filters, because a much larger one Part of the light that is collected from the sample can be fed into the photomultiplier 32.

33ie is shown in Figure 1, need the light guides 16 to 21 and 34 cannot be held in a straight line and their flexibility can be used because of the head need not be held in a fixed position with respect to the remainder of the colorimeter. this has the advantage that the sample and head 12 can be in a remote and inaccessible position while the rest of the colorimeter can be set up under ideal, regulated conditions. This will make the Colorx ^ meter according to the invention especially for controlling many ™

Processes in which a change in color occurs, 7AXKi example in the manufacture of paints, in electrolytic coloring processes, in paper manufacture, in the manufacture of ceramic goods, in the

Coloring of textiles and heat treatments, as with hardening or tempering, because the photomultiplier

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Delivered values can be used to increase the level adjust the process and control it accordingly.

In order to achieve a calibration of the colorimeter 10 au, this can be converted from a single beam instrument into a Double-beam instrument can be converted, with an additional light guide 40 from the lamp housing 38 to the detector head is guided, for example axially through button 24d. Also through the housing 38 is a displaceable Partition wall 41 arranged in which a slot 42 is located. By moving the partition wall 41, the slot

42 with the light guide 34 or 40 in each case in connection brought v / earth, depending on whether the color of the sample 14 is to be checked or whether the instrument is to be calibrated target.

In addition to its use as a colorimeter, the Instrument used as a spectrophotometer, the lamp 36 being driven by a monochromatic light source, for example a monochromator, is replaced and filters 26 and optionally 25 and 46 are omitted.

Repeated measurements of the relative values of the three light stimuli X, Y and Z on a smooth flat opaque; Tiles were made using a head 12a according to Figure 3 performed. The range of fluctuation in the

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nits over a period of 3 months rarely exceeded 0.2 ^, as shown in the following table, where columns 1, 2 and 3 represent measurements were made every six weeks.

Sample Relative Values Relative Values Relative Values

X Ύ ZXY ■ _k Z XYZ * ■

1a 1000 1000 1000 1000 1000 1000 1000 1000 1000

1b 991 994 996 990 994 995 990 994 995

2a 999 1000 1000 999 1000 1000 999 1000 1000

2b 1000 1000 999 1000 1000 1000 1000 1000 1000 i

3a 987 992 995 985 994 995 985 993 996

3b 1000 1000 1000 1000 1000 1000 1000 1OPO 1000

4a 963 960 960 962 960 957 963 960 959

4b 1000 1000 1000 1000 1000 1000 1000 1000 1000

5a 1000 1000 1000 10000 1000 1000 '1000 1000 1000

5b 957 953 950 954 953 949 956 954 950

6a 1000 993 993 1000 992 993 1000 992 992

6b 969 1000 1000 970 1000 1000 970 1000 1000

As can be seen from these results, the sensitivity of the colorimeter of the present invention was one

high order of magnitude and the deviations over a period of time of three months were actually very small.

The colorimeter 10 according to the invention was used

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about the progress of an anodizing process on a Track piece of aluminum. A head 12b according to FIG. 5 was used. The aluminum sample was turned into a Distance of 12.7 cm (5 inches) from the head while the staining procedure was in progress. When the reading indicated the desired color on the digital voltmeter

the procedure aborted. This was repeated for various standard stains, with a very good one Color control for comparison with the standard resulted.

The head 12c according to FIG. 6 was used to control the production of a paint in the one shown in FIG Sometimes used.

The paint was prepared by using appropriate amounts of differently colored bases from four Storage containers 70 to 73 with the help of pumps 74 to 77 pumped with variable delivery rate into a mixer 78 and from there into a collecting tank 79 through a line 80 were fed.

In the line 80 there is a shut-off valve 82 and the feed pipe 60 and the exit pipe 66 are connected to the line 80 on either side of the shut-off valve.

In this way a small rope of paint is used,

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made in mixer 78 through head 12c guided. · ■

The colorimeter 10 was used to determine the color of the paint passing through the head 12c and the output values of the colorimeter were fed into a computer 83 for controlling the process, the output values from the computer 83 to a control device 84 for metering and setting the capacity of the pumps 74 to 77 were given with variable capacity, so that "more or less certain colored basic approaches encouraged and the color of the paint obtained as the end product corresponded to the desired value.

The process of making a paint in this way The results obtained showed the high sensitivity and reproducibility of the measurements with the help of the colorimeter 10, as in determining the color of opaque

solid surfaces was found. (J

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Claims (13)

Claims 1. Colorimeter with an illumination device for a sample whose color is to be measured, and in the Light path switched on filter, characterized in that there are a number of light guides which extend between a light detector and a scanning head which can be set so that that the ends of the light guides receive light from the sample, at least one and preferably most or all light guides in the light path have a single correction filter have, so that the light picked up by the detector from at least one of the light guides the individual correction filter that is assigned to this light guide and the values measured at the detector output correspond to the values X, Y and Z of the normal observer £ according to the definition of the Commission Internationale de l'Eclairage or other function. ' 2. Colorimeter according to claim 1, characterized that there is a readhead to collect the Lights'from a number of directions which gloichmäsoig-im Spaced around the sample, and that there are light transmission devices between the Attastr head and the light detector to the collected - 27 - 109834 / 1OAA To supply light to the detector, as well as having one or more filters through which this can be obtained from some or all directions collected light is passed through before the collected light is fed to the detector so that the output values from the Defctefetor can be arranged so that one of the three primary light stimuli X, Y or Z. of the 'normal observer according to the' definition of the Commission Internationale de L'Eclairage or another puncture. 3. Colorimeter according to claim 1 bin 2, characterized in that the scanning head with the Ends of the light guides is connected in such a way that these are evenly spaced around the sample » 4. Colorimeter according to claim 1 to 3, characterized in that the light from the scanning head is collected in directions which are inclined 45 ° with respect to the plane d of the sample. 5. Colorimeter according to claim 1 to 4, characterized in that the light guides between the scanning head and the detector consist of bundles of fiber optics. - 25 - 109834/1044 6. Colorimeter according to claim 5, characterized in that g e Ic e η η that the number of light guides between the scanning head and the detector is 5 or 6. 7. Colorimeter according to claim 1 to 6, characterized in that the sample to be measured so is arranged so that it is illuminated by the light incident in the right angle to the surface of the sample. 8. Colorimeter according to claim 1 to 7, characterized in that light of essentially constant color is guided through a bundle of fiber optics from the light source to the scanning head for illuminating the sample to be tested. ' 9. Colorimeter according to claim 1 to 8, characterized in that the detector consists of an outer and an inner cylinder, the light guides between the scanning head and the detector end in openings in the outer cylinder and in the inner cylinder, these openings with Openings for the reception of filters or filter combinations are provided i3.Lnd and do-matched openings in the inner cylinder and in the outer cylinder are arranged in such a way that they can be aligned with one another and result in detector output values corresponding to the values X, Y or Z des Norme] observer according to the de fin i ton of Commiüoioj. · ~ 29 - 109834/1044 Internationale de L'Eclairage or some other function correspond. 10. Colorimeter according to claim 1 to 9, characterized in that the light guides , guided light is arranged between the scanning head and detector d ^em that it passes through one or more subtractive filter before reaching the detector. 11. Colorimeter according to claim 1 to 10, characterized overall% indicates that a calibrating device is provided, wherein light is guided directly from a light source into the detector and is not used for illuminating the sample. 12. Colorimeter according to claim 1 to 11, for use as a spectrophotometer, characterized in that that a monochromator is provided as lighting for the sample to be tested and that the light guides f switched between the scanning head and the detector Filters are omitted. 13. Use of a colorimeter according to claim 1 to produce a paint from a mixture of different colored basic approaches by measuring the color values of at least part of the mixture at an interface between paint and air with continuous adjustment of the flow rate for the mixture components according to the specified color value. 109834/1044 Blank page