DE1597239A1 - Color copying process and device for carrying out the process - Google Patents

Description

The invention relates to color photography and, more particularly, to the manufacture of photographic ones positive color copies from color negatives.

In the following description, the invention is explained using the drawing, for example.

If a strip of color negative material is viewed, that of a series of images of a typical Object (i.e. an object that integrates too gray) is exposed or exposed to it, creates; every single exposure doubles the time integral of light relative to the previous exposure. Such a strip is commonly called a Denotes "exposure area" of negatives. Relative to the optimal exposure for the special hegative * -

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material, the exposures form a geometric progression ι A _t x * t x1 »x2, x4, x8. After the exposed strip has been treated or developed with regard to the color, the individual negatives A. B, C, D, £, F have progressively decreasing integrated tranemittances to red light. That is, if negative A is exposed corresponding to a quarter of the Nenji exposure, negative B corresponding to half the nominal exposure, negative C with the nominal exposure, negative D with double, negative B with four times and negative F with eight times the nominal exposure, negative A has the greatest integrated transmittance to botlight and negative F the lowest. This is shown graphically in curve I in FIG. The curves II and III in FIG. 1 show that a similar progression is found in the integrated transmittances with respect to green light and blue light, respectively.

Let it now be assumed that the strip of negatives A to F is copied with the time integrals being set in this way the intensity of botlight, garden light and blue light that reaches the copy material (caused in any known manner) that copies are obtained which after color development in terms of color and density correspond to each other as closely as possible.

Because essentially identical copies are to be produced, the light intensity or exposure time must be sufficient

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when copying a given negative is applied, for each color in roughly inverse proportion "to that integrated permeability of the negative to this color can be adjusted.

Fig. 2 relates to the use of a copy lamp with constant intensity and variable exposure time. In Fig. 2, curves IV, V and VI represent measurements of red light, green light and blue light exposure times which are required to make substantially accurate copies of the exposure area of the negative as described in connection with FIG. 1.

The results shown in FIGS. 1 and 2 can be reproduced in the more general form shown in FIG. According to FIG. 3, the measured optimal copying time has been multiplied by the integrated transmittance T of the negative to light of the corresponding color. The product represents the exposure integral Γ I ° dt, which is required for an optimal copy- jS P ·

borrowed, where I is the light flux which the copy material and t is the time measured from the start of exposure. It can be seen that in the example chosen the green light integral (represented by curve VIII) is essentially independent of the transmittance of the negative remain. The integrals of red light and blue light (curves VII and IX) show a certain dependence on the

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Permeability of the negative. Some of the possible reasons for this dependency are described in "" R.W.G. Hunt (J. Photographic Science, 8, pp. 212-219, 1960). It is nevertheless it is true that the integral remains more or less constant than the corresponding permeability of the Negatives or the optimal copy exposure time. It is for this reason that color negative automatic copiers are designed so that a predetermined time integral of the light reaches the copy material. Incline or Slope controls, as they are by Hunt, loc. Cit. described are applied to the predetermined value in a relatively small amount of the permeability dependent on the negative. It is to be noted that according to FIG. 3, the optimal integral even of blue light is less than 1.9 to 1 over a range the negative transmittance changes from 6.4 to 1.

It should therefore be understood that curves VII, VIII and IX represent optimal integrals of the time integral of the light reaching the copy material, the integrals are essentially independent of the integrated transmission of the negative.

The foregoing may be viewed as a further representation of the Principles of copying color negatives according to the known practice of "integration to gray" are considered, that is described in British Patent Specification 660,099. It is known that this known way of working is the

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The desired feature is that a compensation is created for those factors which influence the ratios of the integrated transmittances to red light, green light and blue light of negatives which represent any objects which in turn integrate too gray a tungsten filament lamp has a red light transmission which, relative to its green light transmission, is smaller than that of a negative which is exposed to daylight. This phenomenon is described in detail by Hunt (J. Photographic Science, JJ _-, pp 109-120., 1963) described.

When color negatives are copied on the principle of integration to gray, difficulties are encountered with those negatives that represent objects that contain an unusually high proportion of saturated color. This type of object is commonly referred to as a "color subject failure". For example, assume that the object is a girl wearing a bright red dress. Areas of the negative containing the dress are essentially unexposed to blue light or green light. The blue and green light permeability of the negative thus correspond to an otherwise identical negative of a girl wearing a black dress. The hot light transmission corresponds to that of a Negati ¥ S · .a girl who has a

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wearing white dress. Accordingly, the red light transmittance can are only half the permeability, .the ge ^ homely corresponds to the accompanying blue light and green light permeability. If such a negative according to the principle of integration is copied to gray, the time of exposure to red light is extended to the predetermined To maintain the time integral of the light reaching the copy material. Accordingly, the copy material is obtained an exposure to red light that is double represents the optimal value, ^ s it is clear that if a negative is to be copied corresponding to an off-color object, the exposure of the copy material is ideal with the proportions of hot light, green light and blue light exposure times (or light intensities) caused that are unchanged from the proportion that is used to copy a negative, the one Representing object that integrates too gray.

Uo to copy color negatives in such a way that a high yield acceptable copies are obtained, the negatives should be divided into two classes.

a) Negatives »represent objects that integrate too gray, and

b) Negatives that represent false color counter-facts

The first class of negatives, class a, should be copied in accordance with the integration-to-gray principle will. In practice it is still acceptable to use this

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To copy negatives by a process that provides a lesser degree of correction, for example by the method described in British Patent Nos. 928,658 or 956,162.

The second class of negatives, class b, should with the proportions of red light, green light and blue light intensities are copied that fall on the negative, and with the proportions of exposure times of the copy material with red light, green light and blue light, which are approximately equal to the proportions that are used when copying Class a negatives are applied.

This means that when copying a negative of class b, the copy material will have an exposure with a contains at least one color integral to light, v; Vsi dieees Integral is directly proportional to the integrated transmittance of the negative to light of that color. According to the invention there is provided a method for copying positives from a plurality of color negatives, in which copying material is exposed to copying light via the negatives, the at least two color components contains whose iniensities or the times of exposure of the copy material with them, controlled in this way that such a color correction is obtained that copying either with fixed color correction or with color correction in inverse proportion to the ratio integrated permeabilities to light this

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Colors of the negative is caused by copying by means of fixed color correction, if the said ratio deviates from a predetermined value by more than a predetermined proportion, and wherein the Copying is caused in the inverse proportion, if the said ratio does not deviate so much, and the selection of the type of color correction caused thereby it becomes that the color correction is prevented in the reverse proportion when the ratio of the integrated permeability deviates from the predetermined value by more than the predetermined proportion.

Preferably manages the reverse Anteiälwert substantially constant Z _e itintegrale of the copying material erreichendem light or the reverse unit value is such that only a partial compensation for the effect of variations of the ratio from the predetermined value to the time integrals of the copying material light reaching created is .

With "fixed color correction" it is meant that the ratios of the time integrals of the products on the negative incident light intensity and light attenuation between the negative and the copy material are present in constant proportions or in constant proportions.

Vorsußswejije is also the fifth color correction a «1 arbkorrelttur with a value if the ratio mentioned by the predetermined word by more than the ^«

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. exceeds the correct percentage, and with a different value, if the said ratio is less than the predetermined value i3to by more than a predetermined proportion

The color correction can be done by controlling the time of exposure of the copy material to each color component of the Copying light or by controlling the intensity of each such component. Usually the copying light contains three color components, which are preferably such that said inverse proportion value is the time integral of that which reaches the copying material Creates light which, when the light is evenly distributed over the exposed area, leads to copy material, that is gray after development.

In a special procedure using three Color components is the color correction between a first color and a second color according to the principle made that the fixed color correction has a value when said ratio by the predetermined value more than exceeds the run predetermined proportion, and has a different value if the ratio is more as a predetermined proportion smaller than the predetermined one Value, and it is made between the third barbel and the first or second color according to the principle, That feate color correction is created when the ratio of the built-in transmittances to light of the first and said one color below a predetermined one

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Ratio falls, namely by a proportion that depends on the ratio of the transmittances to the light first and second color is dependent.

According to a modification of the aforementioned method, the exposure time to light of the third color becomes set in the opposite proportion to the integrated permeability of the negative to this color, than it is permitted by the limitation that the exposure time is not the greater of two times should exceed, these values a first predetermined proportion of the time of exposure with the first Color and a second predetermined proportion of the time of exposure to the second color.

According to another modification of the method according to the invention, the intensity of the copy light becomes the third Color component 30 chosen to be the larger of the two Does not exceed limit values, these values being a first predetermined proportion of the intensity of the copying lighta the first color component and a second predetermined proportion of the intensity of the copy light of the correspond to the second color component.

According to one embodiment of the invention is a method for copying color positives created from color negatives, in which the copy material with copying light is exposed that contains components of a plurality of colors, the duration of the exposures with at least

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two of the color components are controlled in such a way that they all tend to approximate the time integrals of light, correspond to the predetermined values, but are limited by the restriction that the times mentioned from a predetermined mean ratio of exposure times do not differ by more than a predetermined proportion. The stated predetermined values are usually the ones that give a theoretical integration to gray would cause or support.

In the method in which color correction is performed by controlling the time of exposure of the copying material a is controlled with each color component of the copy light, an important variation is that the exposure with light each color component at a time in reverse Proportion to the integrated permeability of the negative towards this color is terminated, as far as it is Allowed by the restriction that the exposure time is not allowed to be a time by more than one to exceed predetermined proportion, which in a predetermined Verhallnia at the time of exposure iii.it a other color component. Within this variation The following conditions may apply.

a) Di «? Zc-i1 the exposure with at least one color component atethat is about one unit Paktor 1n a relation to elnum f (»nie.'i ^ mien Zrit- · intervti 11 <

Π 0 9 fl U / 1 0 i) ')

b) The measured time interval is above a second the pactor that is close to the unit is related to a reference time interval.

c) Means are provided for adjusting the first and second factors in reciprocal relationship, whereby the ratio of the measured time interval to the reference time interval without changing the relationship from exposure time to reference time interval will be changed.

d) The measured time interval is the time it takes for the voltage across a capacitor to reach a predetermined value when the capacitor is charged with current passed through a photoelectric cell that receives a sample of the one color light component of a quality which is used for the exposure of the copy material.

e) Means are provided for the recruitment of the second pactor, and these means speak on the relationship the times of exposure to the individual parabic components of the copier light.

f) The second factor is increased when the measured Time interval, which corresponds to said one color, is smaller than the measured time interval which corresponds to the other color, and it is decreased when the former time interval is larger than the second.

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. Adjustment can be made in the ratio of intensities of color components of copy light so that negatives, which represent objects that are too gray to be integrated, lead to copies that essentially contain the same times of exposure can be produced with the color components mentioned. The setting can be done by means based on the sequence of the termination of exposures with individual color components of the copier light speak to. Such means may comprise an electric motor connected to have a resistor in series with a lamp which creates copy light of a color component changes, and the motor is caused to to decrease the value of the resistance when the exposure with the one color component after exposure ends with a different color, and the motor will continue to increase the value of the resistor if the exposure to one earb component before exposure ends with the other color.

It can further be observed that where the process of color correction is by controlling the intensity of each Color component of copy light is applied, a preferred variation is that the intensity of each Color component of copy light in inverse proportion to that integrated permeability of the Äegati "? e to light this color is adjusted, thereby increasing the intensity of each color component of the light reaching the copy material

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a constant value is kept as far as it is by the Restriction or limitation is permitted that the ratio of intensities of second parabolic components of Copy light does not deviate from a predetermined value by more than a predetermined proportion.

The invention is not limited to such an embodiment, but it is a particularly expedient embodiment an embodiment in which the copy exposures with red light, green light and blue light are essentially from are of the same duration if a negative is copied that represents an object that is too gray to be integrated.

It has been suggested in British Patent Specification 956,462 that when the Copy times are unequal, the exposure or exposures of shortened duration are made with full color correction should take place during the exposure or the exposures of longer duration with less than full color correction should. In this known way of working, the factors mentioned change inversely or inversely and continuously, by the extent of the deviation from the full Correction is entirely dependent on the extent to which the exposures are of longer duration. This means, if a negative has an unusually high density of red light, the exposure time with red light is increased however, the red density abnormality is undercorrected, that is, not fully corrected, f / eitoi -

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when the red density is further increased, the The red light exposure time is further lengthened, but the red density abnormality is further undercorrected. The experience according to the invention differs significantly from the previous method in that the limitation on exposure times that they are by no more than a predetermined proportion of one deviate from the predetermined mean ratio, any other continuous ratio between exposure time and degree of color correction interferes with and actually overflows such a relationship.

Accordingly, an abnormality in red density is caused by a fully compensated for extended exposure time with red light, provided that the extension has a does not exceed a predetermined proportion of the time corresponding to a normal red density. When the abnormality the twist produces an extension of the exposure time corresponding to this proportion, but produces any further increase in red thickening. no further extension the exposure time with red light. Accordingly, at this level of reddish abnormality, the color correction stops completely on. This will become more apparent from the description below, in which convenient numerical data is used to illustrate typical examples of the uses and advantages of the invention.

To make a comfortable copy of a parbo negative

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test, it may be necessary to set the exposures, for example with red light and green light, in increments that do not exceed 10% (i.e. by 0.05 log exposure increments). This is especially true with negatives that show unsaturated colors, such as flesh colors and stones. RWG Hunt has reported ("Printing Color Negatives", J ₀ Phot., Sci., 11, pp. 109-120, '1963) that there are considerable differences in the relative densities of red light and green light due to manufacturing tolerances and different courses of Exposure and development experienced on various rolls of film. In Figure 2 of Hunt's paper it is shown that an adjustment of about 0.35 log exposure units is required to fully compensate for the changes ^{that can occur in as little as 95 a} / ° of rolls of film. (An even larger area would be required to compensate for the remaining part) "If a copier is set so that the central part of this setting area has a special designation (e.g. the same exposure 3-time condition / e 'as used in the British Patent Specification 956,462 proposed), the color control range required for integration to gray of an ordinary object is -0.175 log exposure units in the red-to-green balance. Now if a correction factor of 0.7 is used, as in British Patent Specification 956,462

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is suggested, experiences a negative, which is a correction from 0.175 log exposure units for integration to gray requires a correction of only 0.122 log exposure units. The copy therefore remains around 0.0525 log exposure units undercorrected what is important or characteristic according to the above description.

In the method according to the invention any
The negative of an ordinary object is completely corrected (integrated to gray) if the exposure times do not deviate from the predetermined ratio by more than a predetermined proportion. If this proportion is, for example
- f is 35 °, is any negative which a correction of less than - 0.130 requires log exposure units, fully corrected. However, with a negative, that
requires a correction of 0.175 log exposure units, then the correction is limited to 0.130 log exposure units. The degree of undercorrection is then 0.045 log exposure units, which is a small improvement over the method according to British patent specification 956,462
represents, however, it must be remembered that the
The main part of the negatives has color balances that make corrections
that are less than -0.130 log exposure units. These are fully corrected according to the method of the invention, but would be of a grade
Show undercorrection up to ί 0.039 log exposure units when using the method of British Patent 956.

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The advantages of the method according to the invention will be

more clearly seen when looking at negatives, the so-called Represent "false color objects". Such a negative represents an object that makes one unusual contains a high proportion of a color. For example, in the case of a negative that a girl in a white dress has in front of you red automobile standing shows, the area of the negative in which the red automobile is depicted is a small one Density to blue light and green light, but high density to red light, common photoelectric estimate the relative densities of the negative compared to bot light, green light and blue light can therefore indicate a red density, which is, for example, 0.3 units greater than the value usually associated with the observed green densities and blue densities is equivalent to. If such a negative is copied according to the integration-to-gray criterion, the exposure balance is given to the copy by 0.3 log exposure units not correct. When using the technique with reduced correction, a correction factor of 0.7 will make a difference in the exposure balance of - 0.21 log exposure units compared to the exposure balance, which is an image of an ordinary item on the same roll of film.

In the invention, the "wrong color object" is applied correction kept within the same limits as the correction allowed for a normal negative.

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If these limits - 0.130 log include exposure units, it follows that one green and one Rotfehlfarbengegenstand can not be copied with corrections, vary the exposure units log more than 0,260. In the integration-to-gray process, the selected examples will experience corrections that differ by 0.60 log exposure units. In the method with reduced correction, a correction factor of 0.7 would lead to exposure corrections which differ by 0.42 log exposure units. These results are summarized in Table I shown later.

A comparable table can be drawn up for corrections in the blue / yellow sense, although the limits that are set for the blue / yellow correction, waiter than those used for the red / green correction, according to the example of British Patent Specification 928,658 mentioned above.

It has been mentioned above that the color balance of the copy exposure can be critical with changes that occur 0.05 log exposure units. This is especially true for negatives that depict objects that contain high proportions of unsaturated Purben, for example gray colors and almost gray colors. An object of this type usually integrates to gray and one Copying according to the integration-to-gray criterion therefore leads Xu an ^ l'irbi;.! he · results. The same Erpebnii = 3P has been

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produced according to the method according to the invention, provided that the negative has a balance that requires correction beyond the limits set. In agreement with the known method, which has a reduced correction factor required, negatives with an abnormal color balance will be corrected less than the full * nomnen. It therefore follows that in the known method a lower than the best degree of correction for that species an object is used that is / is most critical in terms of color balance, i.e. an object whose negatives do not deviate from the optimal color balance in such a way that they require a correction of more than, for example i require 0.1JC log exposure units.

An "off-color item" usually represents a Scene a substantial portion of which is of a saturated color. If such a negative in real Color balance is copied, the saturated color is obtained by the maximum density of at least one of the colors of the copy material and also represented by minimum density of at least one color. For example, is a saturated and deep red, respectively, produced by maximum densities of yellow and magenta colors and minimum densities of cyan colors. The amount the cyan color in the copy is usually controlled by the exposure to red light. An extension of the exposure with red light creates more cyan color, which tends to reduce the saturated red of the copy.

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grading, i.e. it leads to the fact that gray is added to the color is, however, the hue is not significantly affected. If the increase in exposure continues with red light is small enough, the amount of cyan added is also small because of the gamma contrast of the Copy material is relatively small at low densities. Perhaps for this reason it has been found that the "wrong color object" is much less sensitive to deviations from the correct balance than the "ordinary" one Object is integrated too gray. Even with that "Off-color object" is the best exposure balance usually the same as an ordinary object. From Table I it can be seen that the invention creates a method which approximates this condition much more closely than the known methods.

It is thus to be understood that in order to carry out the method according to the invention it is necessary to set certain predetermined values. These values can change when a sequence of negatives is copied , but they are predetermined for any given negative in sequence. Accordingly, it is first necessary to predetermine desired time integrals of light for the exposures of the three colors blue, green and red, and these predetermined values are usually those values which produce a theoretical integration-to-gray. Second, it is necessary to have a desired mean ratio of the widths of the

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22-1597233

predetermine exposure with the three colors blue, green and red. The control system must then be adjusted to cause this to occur during the exposure time for each color continues towards the point at which the predetermined integral is reached, and they is checked at the point where further exposure leads to the ratio of the exposure times of the three Colors deviates from the predetermined average ratio of the exposure times by more than a preset amount.

It is to be understood that the invention not only includes all modifications of the basic method according to the invention and as described above, but includes the combinations of devices that are necessarily used when performing the above procedures. Some devices are explained below, for example. All such devices can be conveniently carried out from available electronic components, when the purpose is known.

The basic principles of the method according to the invention have been set out above. Below are some explanations regarding the size of the
given different variables.

If class a negatives (objects that integrate into gray) are to be copied in a copier, with temporary exposure control with regard to the

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lighting with red light, green light and blue light components the ratio of the exposure time with botlight to the exposure time with green light should be changed to compensate for the following factors too create:

(i) Change in red / green timing associated with a set of optimal copies of an exposure area. In the example according to FIG. 2, this ratio changes by less than −15 ° of an average value.

(ii) Change in red / green time ratios required to compensate for differences in negatives exposed to light sources between park temperatures of 3200 ° K and 5000 ° K. The red / green emissions of these sources change in a ratio of around 40 Κ. A negative material with a gamma of 0.7 thus shows red / green density differences, which for this reason are around 0.7 log 1.4 density units differ, ie 0.1 density units. The compensation requires changes in the red / green copy time ratio of about 25 f> or i 12 l / 2 from a mean value.

(iii) Change in the red / green timing ratios as required is to compensate for manufacturing and development differences between different negative materials. This change can correspond to about 15%.

From the above it can be seen that the red / green

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Copy time ratio for a negative of class a never of a particular mean ratio by a factor should deviate which is greater than the product of the individual factors specified under i, ii and iii above. The maximum deviation from the mean ratio is thus given by a factor of 1.15 '1, 125 * 1.15 = 1.55 to 1. In practice, the great majority of class a negatives require a factor that is unity much closer.

If class b negatives (off-color objects) are copied according to the integration-to-gray principle, correspond the changes in the red / green time ratio factors that is greater than the maximum factor of 1.55 to 1 as described above. Factors from 2.0 to 1 are great common. In practice, a distinction between class a and class b negatives can be made simply by observation take place whether a predetermined ratio of red and green exposure integrals a deviation of a typical ratio of red / green exposure times by a factor exceeding a particular value. The di & h implied value above is 1.55. Since negatives of class a seldom changes in this To generate extent, it can be advantageous in practice to use a smaller value, for example 1.35.

It is known that negatives are printed on a single strip which is exposed under similar conditions and

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that require the same color correction to produce decent copies regardless of whether they represent off-color objects or not. Known types of automatic color copier do not lead to satisfactory results because the color correction applied to an off-color object is different from that is different, which is used for an object which is too gray to be integrated. In the case of the invention, therefore a class b negative (i.e., a negative representing an off-color item), due to an unusual portion integrated transmittances for light of any two colors red, green and blue stated “The ones with reference to Color correction applied to those colors is then limited to a value known to be for negatives is acceptable that represent objects that are too gray.

This principle is further illustrated by the illustration in FIG. 4, in which the ratio of integrated transmittances Ψ-ο and Tn to light of two colors (red and green), multiplied by a constant k ^, is shown on dts ibscissa on a logarithmic scale is.

This constant k. represents the mean of ϊ ^ / ϊβ for a represents a large number of negatives. The ordinate in Fig. 4 represents the color correction between red light and greenish. This is in a logarithmic scale all the ratio of the individual Products of light intensities I «and 1 ^, which are applied to the negative

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impinge, and the exposure time t _R and t "of the copy material.

The factor k ₂ represents the mean value of Ι _β * _Ε / ΐ (} "& (} ^ Hr the same large number of negatives.

In Pig. 4, the broken line represents the known practice of British Patent Specification 660 099, ie copying according to the integration-to-gray criterion · In this, an abnormality of integrated permeabilities in the ratio of 2 to 1 produces a change in L ·, t “/ I _R t _R in the ratio 2 to 1.

The dotted line in Pig. Figure 4 illustrates the known practice according to British Patent Specification 956,462 or US Pat British Patent 928,658, i.e. copying with a degree of correction corresponding to 0.7 of the value which corresponds to the method of British Patent Specification 660,099.

The solid line WXYZ in Pig. 4 provides an example of the method according to the invention. The middle section XY indicates that negatives of class a according to FIG British Patent 660,099 to be copied. Sections WX and ZY indicate that class b negatives should be copied with a fixed degree of color correction, where * the direction of the correction corresponds to the sighting, which is indicated by the known methods mentioned.

Modified designs and arrangements are of course possible. For example, class a negatives

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can be copied with a lower degree of correction. Such a system would be represented by the line WX ¹ Y ¹ Z in Figure 4. Furthermore, the sections WX and YZ, although drawn parallel to the abscissa, can have a small gradient, either positive or negative. Such modified arrangements are more complex to implement in practice and less satisfactory in performance.

Although a simple means of controlling the ratio of red exposure by the above principles and green exposure created, precautions must be taken if the principle is extended to include the addition of blue light exposure. In Fig. 2 it is shown that the ratio of optimal copy exposure times with blue light and green light varies in an exposure range of negatives changes more than the ratio of red exposure time to green exposure time. That The ratio of blue exposure time to red exposure time changes to an even greater extent ^. The ratio of blue exposure time at any other exposure time must therefore allow the following factors:

(i) Change in blue / red time ratios in an exposure area. In FIG. 2 this ratio changes to - 40 ^c / o In a mean value.

(ii) change in blue / red time ratios as required is to compensate for differences in negatives that are ■ exposed to different light sources. The compen-

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sation may require a change in the blue / red copy time ratio of -25 1 ° .

(iii) Changes in blue / red time that are required to compensate for manufacturing and development changes and which can amount to - 15%.

Accordingly, class a negatives can be a correction of the Blue / red copy time ratio corresponding to the product of these individual factors, i.e. a combined Factor of 1.40 * 1.25 * 1.15 = 2.0 to 1.

It is unsatisfactory as a means of discernment a transmittance ratio abnormality of 2 between negatives of class a and class b to use. Off-color objects that fall into this range or a smaller one are classified in class a and the resulting copies will not be satisfactory.

It has also been found that in many instances it is undesirable to allow one to be uncommon high blue transparency leads to a shortening of the exposure times with red light and green light. If allowed the copies obtained often have too low a density.

An execution in which these difficulties are overcome be is as follows »

The times of exposure to red light and green light are controlled as described above so that

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their ratio of a predetermined value by no more as a pre-determined factor (e.g. 1.35 to 1) deviates. The changes in the blue transparency (or the exposure time) are not made possible, the individual red exposure and to influence green exposure times or their ratio. The time of exposure to blue light is up limited in such a way that it does not exceed a time by more than a factor χ which is longer of two times, namely y multiplied by the red exposure time and ζ multiplied by the green exposure time. The values of y and ζ corresponding mean values of blue / red and blue / green copy exposure times for a large number of Negatives. The factor χ can range from 1.0 to 1.5. Work carried out according to FIG. 2 showed good results Results with a value of χ = 1.2.

FIG. 5 shows the dependency of the blue / grtin color correction which is carried out by such a copier in accordance with the ratio of the integrated green and blue permeabilities of the negative. FIG. 5 should be compared with FIG. 4. Referring to Figure 5, note that the color correction is in reverse proportion to green / blue transmittance for values of f ^ / lg <^ 1.2 / k, where k, the mean of ^ q / Eq for is a large number of negatives. The color correction ceases to be dependent on ¹ SqZ ^ -Q _{at a value of Τ β} / Τ _Β , which never exceeds (1.2 χ 1.35) k, * 1.62 / k ^. The value of

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T _& / 3L, at which the limit is set, depends on the value k ^^ / Trt as this determines the relationship between red and green copy exposures in accordance with the line WXYZ in FIG.

When a copier is set so that for average negatives the red, green and blue exposure times are all the same, y = 1 and ζ = 1. In a copier in which red light, green light and blue light exposures progress concurrently, leads this leads to a particularly simple design. If X = 1.2,

the blue light exposure (if the blue light exposure integrator has not already caused it ^{to cease 1} S ^ t) is terminated after a 20 # extension of the time to cease red light and green light exposures.

The performance of such a copier is shown below explained to show how it meets practical requirements.

(i) the copier is set so that a "dead heat" condition / ^ of negatives in the Center of the exposure area is created, i.e. on the negative which experiences twice the nominal exposure.

The copier guide in an exposure area of negatives can be found in the table below (Tables) are summarized with reference to. 2 established iat.

0098U / 1062

Table II: Exposure range of negatives exposed to light of ordinary dyeing temperatures.

Negative copy exposure limits proportion in which

exposure times (remiv to the copier at Pehlfarben-

(x nominal length of the shortest time) clearing times subject to the copy clearing) time must increase

to experience the limitation

S G BE GBRGB

0.25 1.64t _b 1.44t _b t ^ 1.35t 1.35 t _r 1.20 ± _r 1.18 1.54 1.97

2.0 t _r t _g t _b "» «1.55 1.35 1.20

ε, Ο t 1.17t ,, (1.44t_) "" 1.20t 1.58 1.16 0.97

The value of 1.44t shown in brackets indicates that the x8 negative produces an optimal copy with a blue copy exposure, the duration of which is 1.44 times the duration of the Eot exposurea time. However, the blue exposure is completed at 1.2 times the time of the green exposure, which in turn is 1.17 times the red exposure. Accordingly, the actual blue exposure is 1.17 x 1.20t _r , ie 1.40 times the red exposure time. Accordingly, with an x8 negative, the blue exposure time is only 97> of the optimum. The disadvantage or the lack of 3 $> is not discernible in practice and protection against blue-bleach color objects to which dense negatives are assigned is to a great extent desired.

ii. Similarly, Tables III and IV can be listed in order to summarize the performance when copying negatives with light of high and low parabola peratures to be exposed ..

00981 A / 1 062

15S7239

Table III: Exposure range of negatives exposed to light of high coloring temperature

Belioh- Kopierbeliöhtungs- Limits of the faeces of the. times (relative to the pierexposure negative! shortest time); times
(x denomination j \

clearing)]

0.25 2.00 8.00

| 1

GB 1.30t _b t _b

1.12t _r 1.25t 1.32t ,, (1

, 35t 1.35t,

1 | i

_r , 8OtJ "

! Proportion in which for wrong-colored objects the copying time must increase in order to experience limitation

SGB, - 1.33 1.37 1.58

1.51 1.21 1.08 1.78 1.02 0.88

A χ 8 negative that has been exposed to light at hq «r - ^ arbtemperature experiences a light exposure that is 12 % below the optimal exposure. This is just about observable, but not seriously. In fact, 12% represents only half of the step taken between successive blue light color correction buttons on an automatic copier.

0098U / 1062

Table IV: Exposure range of negatives exposed to light of low dyeing temperature

Beiich copier exposure limits the Ko proportion in which management of the times (relative pierce exposure in case of false color counter-negatives the shortest time) the copying (x nominal time must increase)

licht) limitation to him

travel

RG BRGBEGB

O .25 ² »19t _b 1 , 64t _b 1 t _b 1.35 t _g 1.35 ^t r ¹ , 2t _r 1 , 01 1 , 80 2, 62 2 oOO 1 »34t _b 1 , 14t _b * b " 1 , 2t _r 1 , 15 1 , 59 1, 61 8th .00 1 , 01t _g , 08t _g - Il H 1 , 34 1 , 36 1, 21

From Table IV it can be seen that exposure times are optimal for all negatives in class a that are exposed to light with a low color temperature. For this negative is the protection against red wrong color counterpart Well. Protection against green or blue off-color objects least satisfactory among the underexposed negatives.

(iii) Tables II to IV show that in most cases an additional change in exposure time of i 15 f> is permitted in order to compensate for unusual values in the transmission ratios resulting from changes in manufacture or development. Cases in which a 15% increase in exposure time would not be achieved are as follows

a) Red exposure of a χ 0.25 negative that was recorded with a Source is exposed to low color temperature.

0098U / 1062

b) Blue exposure of a χ 8.0 negative which has been ^{exposed to a 1} source of ordinary coloring temperature.

c) Blue and green exposures of χ 8.0 negatives which have been exposed from a source of high coloring temperature «,

The combinations of variables occur so rarely that there is little effect.

The invention is explained below with reference to the drawing, for example:

Fig. 6 is a schematic view of an automatic Farbnegat ^ copying device of known type.

Figure 7 is a schematic block diagram of one of

three similar channels of a control circuit according to the same known art.

Tig. Fig. 8 is a schematic block diagram of the exposure control circuit of a known automatic color negative copier.

FIG. 9 is a schematic block diagram of the additional circuitry associated with that of FIG. 8 is used.

Fig.10 is a circuit diagram of the

used to be a time ratio controller su create.

Fig. 11 is a schematic block diagram of a flow

Kreieee for automatic adjustment of the relative Intensities of hot *, green * and blue light components

0098U / 1062

1597233

Pig, 12 is a circuit diagram of the arrangement shown in FIG soft motors through the copier Can adjust rotation,

13 is a schematic block diagram of one embodiment of the lending tax current crisis, the arrangement of the time relationship controllers is shown.

Fig. 14 is a high-level block diagram in which Details of the potentiometers and the timing haltniacontroller are shown. In Fig. 6 is an automatic parabolic negative copier known type shown. According to Pig »6, light from three lamps 1, 2, 3 runs through a diffusion screen 4 into an integrator box 5 at its lower end * The The upper end of the integrating box 5 is provided with a diffusion screen 6 so that a negative 7 is evenly illuminated and an image of it is formed through a lens 8 on photosensitive copy material 9 * The lamps 1, 2, 3 are with Parb selection filters, 11, 12, 13 sinks, each of which allows a different band of three bands of the spectrum to pass through, namely red, green and blue, respectively. An oblique mirror 10 directs the light from the lamp 1, which passes through the red filter 11, onto the diffuser An enclosed mirror 14 directs the light from the lamp 3 which passes through the blue filter 13 onto the Diffuser 4. An inclined partial reflector 15 directs a part

0098U / 1062

of the light passing through the negative 7 and the lens 8 to a lens 16. That which reaches the lens 16 Light enters a photocell box 17.

In Fig. 7, one of the three similar channels of the control circuit is shown in a schematic block diagram, wherein a photocell 21 in the photocell box 17 according to FIG. 6, a closure in a known manner of the levels 18, 19, 20 (Fig. 6) controls the exposure of the copy material 9 with light of one of the colors red, green or to finish blue. A similar channel of the control circuit controls the exposure to light of each of the three Colors, red, green and blue.

According to FIG. 7, in the passive state, current from an energy supply 30 keeps an actuating member 36 excited so that the shutter 27 is closed and light coming from the copy lamp (12 or 3 according to FIG. 6) cannot reach the copy material 9. The actuator 26 may comprise a solenoid in series with a thermionic valve or transistor. To expose a copy, a switch S _{1 is} closed. Current from the supply 30 then sets a bistable trigger device to an "off" or "0" state. An "OH" gate 25 then receives two "0" inputs and outputs a "0" output to the actuator 26. Accordingly, the actuator 26 is de-energized and the shutter 27 opens under the control of a return spring, not shown. By opening it

0098U / 1062

of the shutter 27, copy light can fall on the copy material 9. A portion of the copying light also falling on the photo ropes 21 leads to a current which is proportional to the intensity of the copying light reaching the photocell 21. Current from the photocell 21 flows to a current integrator 22, which is usually a capacitor. The integration of the current by the integrator 22 leads to a voltage that increases over time. The output voltage of the integrator 22 is applied to a voltage adder 23. The other input to the adder 23 is a voltage that is received from the reference voltage source 28 and is attenuated or weakened by an adjustable potentiometer 29. The two inputs to the adder 23 are of opposite polarity. Accordingly, the output of adder 23 falls to zero when the two inputs are equal in size. The output of the adder 23 is applied to the trigger device 24. As long as the output of the integrator 22 is smaller than the output of the potentiometer 29, the adding device 23 provides an output which causes the trigger circuit 24 to apply a "0" signal to the "OR" gate 25, so that the actuator 26 remains in the de-energized state. When the photocell 21 causes the integrator 22 to charge itself sufficiently, the output of the ^{adding device 23 falls to zero, the trigger device 24 delivers a "1 M} output to the ^H 0E" gate 25, the actuating device

0098U / 1062 BAD ORIGINAL

gungsorgan 26 is excited and the shutter 27 closes, in order to end the exposure of the copy material 9 to the light of the color to which the photocell 21 responds.

It should be understood that in color automatic copiers in accordance with the known art, three circuits are used, which correspond to the circuit shown in FIG are similar and each of which corresponds to a separate color red, green and blue, respectively. For each of these circuits is a red selection filter, green selection filter or blue selection filter arranged in the path of the light reaching the photocell 21.

It is also customary in the art to provide a switch Sp which can be closed by hand so that, if necessary, the actuator 26 can be energized to prematurely terminate the exposure of the copy material 9, usually only one Power supply, supply 30 may be required in connection with all three channels, and switches S ₁ and S ₂ may be common to all three exposure control channels.

In Fig. 8, the exposure control circuit is a known one automatic Farbnegat ^ copier shown. The numbered circuit elements in FIG. 3 correspond the elements with the same reference numbers in Fig. 7 and the additions r, g, b relate to the botlight exposure, Green light exposure and blue light exposure control channels, respectively.

0098U / 1062
BATH

Now that a known embodiment of an automatic Negative copier is described, an embodiment of the invention when applied to such Copier described. Pig. 9 is a schematic Block diagram of the additional circuit that connects with the circuit of FIG. 8 is used to necessary limitations with regard to the time relationships to create copy exposures with red light, green light and blue light. Referring to Fig. 10, there is shown the circuit arrangement used to operate a time ratio controller of the type indicated by blocks 37 and 39 in FIG.

Referring to Fig. 10, a bistable circuit generates 4-1 alternating ones fixed positive or negative output voltages when responding to changes in the input voltage, which at an input terminal 40 is applied. When the input voltage is zero, the output voltage applied to diodes 42 and 44 is pojsitive. When an input voltage "1" is applied, the output voltage becomes negative. In the ready-stock position (i.e. before copying begins) the input at 40 is in the "1" state. De / output of the bistable circuit 41 is then negative and a current then flows through the diode 44, a resistor 45 and a Diode 46 from earth. The current flowing in this way only creates a small voltage drop across the diode 46 and the input to a phase reversing amplifier 47 can therefore be considered to be essentially

009814/1062 BAD

must be kept at ground potential. While the input to the amplifier 47 is in this way at ground potential is held, the output of amplifier 47 is (and thus the input to a trigger 49) also essentially at ground potential, ■ i.e. in "0" State. With a "0" state of the input, the trigger circuit 49 creates a "1" output at a terminal 50.

When a "0" input is applied to terminal 40, bistable circuit 41 provides a positive output voltage at the diodes 42 and 44. The diodes 44 and 46 then stop conducting and a current flows through the diode 42 and a resistor 43 to raise the potential of the input of the amplifier 47. Because the amplifier 47 reverses the phase creates, any increase in the input potential produces a decrease in the output potential, and a feedback current flows through a capacitor 48 to counter the increase of the input potential of the amplifier 47 (incomplete) to oppose. The design of the phase reversal amplifier 47 and the feedback capacitor 46 can, for example, be that of a known Miller integrator circuit correspond. In this circuit, while the bistable circuit 41 takes a positive output voltage manages to increase the negative output voltage of amplifier 47 linearly with time. The magnitude of the increase, -dV / dt is given by h.V / R, where h is a constant, V the positive Output voltage of the bistable circuit 41 and R the

0098U / 1062

BATH ORIGINAL

Value of resistor 43 is. As long as the output voltage of the amplifier 47 remains negative, the delivers Trigger circuit 49 has a "Ο" output on the terminal

When a "1" input is again applied to input terminal 40, bistable circuit 41 provides a negative output voltage V to diodes 42 and 44. Diode 42 then ceases to conduct and a current flows through diode 44 and a resistor 45 »to reduce the potential of the input of amplifier 47. The feedback capacitor 48 in turn acts to incompletely counteract the change in the input potential of the amplifier 47. Accordingly, the rising from _fe angspotential of the amplifier 47 (in the direction towards the potential) by an amount dV / dt, which is given by HR / R, where R is the resistance value of the 45th When the potential of the output of the amplifier 47 once reaches ground potential, the input to the trigger circuit 49, in turn, ¹¹ O, "and in turn, the trigger circuit 49 provides a" 1 "signal to the output terminal 50th

From the foregoing, it can be seen that when the input voltage at terminal 40 changes from ^H 1 ^M to "0", the output voltage at terminal 50 changes to "0" immediately. When the input voltage to terminal 40 thereafter ^{returns to n} 1 ^M after a time t, the output voltage at terminal 50 returns to ^M 1 ^M after a time t (liq / p) where

009814/1062

When V and V are made equal, q / p = R / R.

The time ratio controller according to FIG. 10 can thus used to define an interval t (1 + q / p), which begins when there is a response to an input voltage change and its duration is the duration t of the input voltage change is proportional and equal to the interval t by a prescribed proportion q / p of t.

FIG. 9 shows how two such time ratio controllers can be used in connection with a copier according to FIG. B in order to impose certain limitations on the ratios of the exposures of the copy material with red light, green light and blue light. According to FIG. Connections 31 ', 32', 33 ', 34', 35 'are connected to the connections 31, 32, 33, 34, 35 of the circuit according to FIG. 8. When switch S ₁ (Pig. 8) is closed to initiate copying, the outputs of "OE" gates 25r and 25g change from the ^H 1 "state to the" 0 "state. Both inputs of an ¹¹ OR" gate 36 therefore change tob ⁿ 1 ^H state to "0 ^M state, so that the input to the time ratio controller also changes from" 1 "to" 0. "It is now assumed that the red light integrator 22r generates an output voltage which is the output of potentiometer 29r is equal and opposite, and that this occurs before the corresponding operation occurs with respect to components 22g and 29g

0098U / 1062

BATH ORIGINAL

"OR ¹ * gate 25r has a" 1 "output to operate the actuator 26r and close the shutter 2? R. The" 1 "output from the gate 25r is applied to the" OR "gate 36 so that a" 1 "input to the time ratio controller 37 is generated. The input from 37 has then ^{remained in the 11} O" state for a time t which is equal to the duration of the hot light exposure. The output of the time ratio controller 37 therefore returns to a "1" state after a total time t (1 + q / p). If the spray light exposure is not ended within this time as a result of the action of the integrator 22g, the generation of a "1" state es at: the output of the time ratio controller 37 leads to the appearance of a "1" state at the input of the "CB" gate 25g and thereby to a termination of the green light exposure. The green light exposure time can therefore not exceed the hot light exposure time by more than the proportion (1 + q / p); Exceed 1.

Since the circuit connections are arranged symmetrically relative to the channels controlling the red light exposure and the green light exposure, it is to be understood that if the green light exposure integral should be reached before the red, the time ratio controller 37 prevents the red light exposure time from increasing the green light exposure time by more than the same proportion , namely (1 + <$ / *) '· 1 »exceeds.

When the intensities of the red component and the green component

009814/1062 ORIGINAL BATHROOM

component of the copy light ao are proportionally present that the mean hot light exposure time and green light exposure time are essentially the same, ea has been found satisfactory to use a ratio of q / = 0.2, where (1 + q /) = 1.2 The combination of the circuit of FIG. 9 with that of FIG. 8 then ensures that neither the bot light exposure time can exceed the green light exposure time by more than 20 f> nor the green light exposure time the red light exposure time by more than 20 5 *. Thereby is prevented that the ratio of red light to green light · exposure time is changed sufficiently to deviations found in the ratio of the integrated transmittances of the negative compared to red light and green light from more than - to compensate 0.08 log units from an average value.

It is of course possible to have a similar symmetrical limitation on the ratio of Provide red to blue light exposure or Grtinlicht blue light exposure time in an analogous manner. In practice However, it has proven to be preferred to provide that the blue light exposure times differ from the red and / or green light exposure times are dependent, but that the blue exposure time does not limit the red or green exposure time creates. The embodiment shown in FIG. 9 leads to this preferred result. if the switch S. is closed to initiate copying,

0098U / 1062

BAD ORIGINAL? * ^: ^ ^R

-45- 159723a

see the outputs of ^M 0H ^H gates 25r and 25g change from "1" to "O ^11. Accordingly, the output of an" AND "gate 38 also changes from" 1 ^M to "0" until the red and green exposure ends are. Only when the gates 25r and 25g again deliver an "I" output does the "AND" gate 3 & deliver a "1" output to the time ratio controller 39 ^M output is generated and applied to the "OE" port 25b to terminate the blue exposure, if it has not already been terminated by the action of the integrator 22b, thus preventing the blue exposure time from increasing by more than a prescribed increment (x-1) the longer of the two exposure times, namely that of Eotlicht or that of green light, In practice this extension can be made as small as 10 ^ or even smaller.

It should be noted that when a negative to be copied, which with light of unusually low color temperature is exposed, the blue light exposure by the integrator 22b a considerable time before the end of the exposure is terminated with red or green light, as shown in Figure 9 The embodiment shown intentionally prevents the hot light exposure or green light exposure from being referenced a prescribed extension of the blue light exposure time, as such a limitation provides full compensation

009814/1062 BAD

by the integrators 22r, 22g and 22b with respect to the Effects of exposure of the negative are light lower Park temperature would be prevented »

With the embodiment described so far with reference to FIG. 9, even excessively red-exposed copies of Negatives are obtained that are unusual with light, are exposed to lower color temperature, d.iu with light of a clear or transparent lightning layer or "Phot of lood" IaBp. This arises. from the fact that, albeit the exposures with blue light and Green light through the effect of the integrator 22b or 22g can be finished, the exposure ait red light at de? prescribed time extension (e.g., 20 #} the green * light exposure time is ended. ±> a preferred one Execution, this disadvantage is overcome in that a "1" signal appearing at terminal 34 is used to energize relay 51 which contacts 52 closes to an additional resistor 53 to the resistor 43 of the time ratio controller 37 in parallel switch. When copying negatives of normal color balance the blue exposure (if any) will only be something ended before the eot exposure or green exposure. Accordingly, the resistor 43 (if at all) is placed in lift closure for only a small part of the time which the output of the bistable circuit 41 is positive. The timing ratio determined by the controller 37

0098U / 1062

BATH ORIGINAL

is then due to the shunt effect of the resistance 53 little or no influence. If a negative is to be copied, the one with light with a low color temperature has been exposed, however, the blue light exposure by the integrator 22b becomes considerably ahead of the time point ends at which the green or red light exposure ends will. Accordingly, resistor 53 becomes resistor 43 for a considerable portion of the time in Shunt connected, during which the bistable circuit 41 (in device 37) is positive. The value of the Resistor 53 is smaller than the value of resistor 43. Accordingly, the input eu to amplifier 47 »during the bistable circuit 41 is positive, raised to a higher voltage than is the case without the resistor 53 would be, and the extension of the green exposure time determined by the controller 37 (and the duration of the Eot exposure time limited) is increased considerably.

Specifically, when the value of the resistor is one fifth of the value of the resistor 43, an exposure time which is finished at half the time of the green exposure causes an allowable increased extension of the bot exposure beyond the 5 exposure from the usual extension of 20 #> of 3.5 x 20 fo _f ie 75% ..

Although it is possible to work with the invention as described above by using the relative

0098U / 1062 BAD ORIGINAL ^

Intensities of the red, green and blue light components in the Copy light are set by hand, it is advantageous to use an embodiment of the invention, in which this setting is made by automatic means, - ^ he automatic setting is carried out so that it is ensured that for typical negatives of a prescribed class essentially the same times for the integrators 22r, 22g and 22b are required to operate the corresponding triggers 24r, 24g and 24b. An operation for making such automatic adjustment will be described with reference to FIG.

The circuit arrangement according to * 'ig. 11 can be related with the known type of copy control circuit according to Figure 8 can be used. In Figure 11 are the connections 31 ″, 32 ″, 34 ″ and 54 ″ are connected to the connections 31, 32, 34 and 54, respectively, according to FIG. (This can be in addition to the Connection of the circuit according to Figure 9 with certain of these connections? ·

When switch S. (Figure 8) is closed to initiate copying, a "1" signal appears at terminal 54 "and is differentiated by the combination of a capacitor 64 and resistors 63, 73. The differentiated signal is in the form of a Exponential pulse is present and is applied to bistable circuits 58 and 58 to cause them to provide "0" outputs and thereby de-energize Beiais 59, 69. Eelais 59 are contacts

0098U / 1062

BATH ORIGINAL ^r

15B7233

60 which control the direction of rotation of a split phase induction motor 62. Similar contacts 70 are assigned to the relay 69 and a second phase induction motor 72; for the purposes of the description it is assumed that the contacts 60, 70 are brought into a state corresponding to the de-energized state of the relays 59, 69. It is also assumed that in this condition, closure of contacts 82 causes the shafts of motors $ 2, 72 to rotate clockwise when an appropriate AC power supply is connected to terminals 83 and 83a. The operation of the contacts 60 and 70 then connects the alternating current supply to the opposite pole of the phase gap capacitor 61 and 71. Accordingly, the associated motor 62 and 72 rotates in the opposite direction, ie counterclockwise. It should be noted, however, that when the _{copy initiation switch S 1} is closed, a relay 81 is de-energized and its associated contacts 82 are open, as shown. Accordingly, neither motor 62 nor motor 72 is rotating immediately.

Before the contacts 82 close, the direction of rotation is each motor 62, 72 is preselected by the relays 59, 69. This is done in the following way:

At the beginning of the copying cycle, the connections 31 ", 32» "0 ^M signals from the" OR "gates 26r and 26g (Pig. 8). When the exposure to red light is finished, changes

0098U / 1.062 BAD ORIGIMAI.

the signal on terminal 31 * ¹ to a "1 ¹¹ signal. -Üas" 1 ^W signal is differentiated by capacitor 55 and resistor to create an exponential ^{pulse which is applied to M} 1ND "port 57" if the green exposure has already ended, an ^M 1 ^M signal is present at connection 32 "and the gate 57 supplies a pulse to the bistable circuit 58, so that the output supplies a" 1 "signal and thus energizes the relay 59. If, on the other hand, the If the exposure to green light ends after the exposure to red light, the gate 57 does not respond to the exponential pulse supplied by the capacitor 55. Accordingly, the relay 59 remains de-energized in this case Completion of the red light exposure and the green exposure ¹ ', after exposure are closed, the motor 62 rotates clockwise if the green exposure has been longer than the ßotbelichtuug, and rotates counterclockwise if di e The green exposure was shorter than the red exposure.

Components 65 to 69 operate in an analogous manner to components 55 to 59. However, the "IND" gate 67 has a special input and accordingly the relay 69 is energized when the blue light exposure decreases after the red light and green light exposure is complete continues. Demgeaäß the motor 72 rotates at closing of the contacts 82 in the counterclockwise direction when the egg _au b _e exposure time is the longest.

009814/1062 ,.

BATH ORIGINAL

When the switch S ₁ is closed, the exponential pulse passing through the capacitor 64 is also applied to a monostable circuit 74. Upon receipt of the pulse, the one-shot circuit 74 changes the state of its output immediately from "1" to "0". After a fixed time interval t, the output of the circuit 74 returns to the "1" state. When each "OR" port 25r, 25g and 25b (Figure 8) has generated a "1" signal to stop copying the colors red, green and blue, those appearing at terminals 31 ", 32", 34 "will cause "1" signals that an "AND" gate 75 produces a "1" signal at its output. The output of gate 75 is differentiated by a capacitor 77 and resistors 76, 78 to produce an exponential pulse which is fed to an "AND.""Gate 79 is applied. If this pulse is received while the output of the monostable circuit 74 is in the" 0 "state, the gate 79 cannot produce an output and the contacts 82 are not closed to prevent the motors 62 from rotating," 72 to effect. If, on the other hand, the exponential pulse passing through the capacitor 77 occurs after the output of the monostable circuit 74 has returned to the "1" state, the gate 79 delivers a pulse to an apnostable circuit 80. When this pulse is received, the output of the monostable 6 changes Circuit 80 from the "0" state to the "1" state and an Eelais 81 is thereby for a time interval one

009814/1062 ORIGINAL BATHROOM

Energized duration t defined by circuit 80. m

It is thus to be understood that for "every negative that requires a copy exposure exceeding time t, motors 62 and 72 are caused to stop for a time t and rotate in directions resulting from the sequence of the termination of the red, green and blue light exposures depends. It should also be noted that very short copy exposures (e.g. those that result when the copier is operated without a negative or with an unexposed negative, namely in the gate) cause the motors 62, 72 to rotate.

In Fig. 12, a simple embodiment is shown in which ¹ * the rotation of the motors 62 and 72 can be done in order to set the copier so that for typical negatives that require copy exposures longer than the time t, the exposure times for Red, green and blue lights are essentially the same. According to FIG. 12, an alternating current supply to connections 88 and 89 is switched in such a way that current is supplied from connection 88 via a sliding contact 86 of a potentiometer 84, via part of the potentiometer winding to connection 91, via lamp 5 which supplies the blue component of the copying light and then to the terminal 89 can flow. Current continues to flow from sliding contact 86 through the other part of the winding of potentiometer 84 to terminal 90 and then to sliding contact 87 of a potentiometer

0098U / 1062

BATH ORIGINAL

- 53 - 1597233

85. Current accordingly flows through the two parts of the winding of the potentiometer 85 and leaves it via connections 92, 93 to flow through lamps 2 and 1 to the supply port 89. The lamp 2 supplies the green Component of the copy light and the lamp 1 the red component.

It is to be understood that the relative intensities of the red, green and blue light components of the copy light, obtained from lamps 1, 2 and 3 depend on the positions of the potentiometer sliding contacts 86, 87. These are coupled to the shafts of the motors 72, 62, as shown in FIG. 12 by broken lines is. Thus, if blue is the final color to finish copying, the circuit of Figure 11 will cause the motor 72 rotates the potentiometer contact 86 counterclockwise during the time t. Through this rotation the resistance between the contact 86 and the connection 91 »which is connected in series with the lamp 3, decreased. At the same time, the rotation of the contact 86 increases the resistance between it and the one with the Lamps 1 and 2 connected in series connection 90 enlarged. Accordingly, for the next copy exposure is the intensity of blue light is increased and the intensities of red light and green light are reduced. By choosing the motor speed, the duration of the time interval t and the resistance of the potentiometer 84 is achieved that the

009814/1062 ORIGINAL BATHROOM

The intensity ratio of construction light to red light is only on the order of 1 # for a single work des fellais 81 (Figure 11) changes. A dozen or more typical negatives must therefore be copied before the Contact 86 reaches a position in which the intensity of the blue copier light is so enlarged that dl © Blue exposure times are shortened in such a way that they essentially correspond to exposure times with red light and green light are the same. Thereafter, the contact 86 moves in opposite directions if subsequent negatives or groups of negatives can be copied. The mittfclar « However, the position of the contact 86 is automatically adjusted to substantially ease the copy exposure times of the three colors to maintain.

It is useful to provide some amount of backlash or idle in the duplication between motor 72 and contact 86, equivalent to the movement of contact 86 required to underlay an underlay; of about $ 10> in the To produce the ratio of the intensity of blue light and hot light.

In a very similar way, the circuit according to FIG Pig. 11 that the motor 62 rotates the contact 87 of the potentiometer 85 such that the red copying time for the typical negative and green copying time are made the same. If the green copying times are longer than the bot copying times, the The intensity of the lamp 2 increased and that of the lamp 1 decreased.

0098U / 1062

The above-described execution forms relate to a known type of copier using separate lamps as sources for the red, green and blue Component of the copy light. In such a copier it is advisable to use essentially the same Beiich * tuning times for the three color components of the copy light, namely red, green and blue to be provided. With an important one modified known type of copying device, however, the three components of the copying light of one single lamp derived. In this modified copier, it is not usually appropriate to use continuous Provide adjustment of the relative intensities of the red, green and blue components of the copy light Accordingly, a modified embodiment is explained in order to show that the invention with regard to its applicability is not limited to a single known type of copying apparatus and in particular is not limited to a copying method is limited in which the times of exposure to red, green and blue light are essentially the same are held.

The electronic exposure control circuits of the modified known type of automatic color negative copier may be generally of the known type as disclosed in Pig. S is shown. In order to apply the invention to such a copier, time _ratio controllers are used in the usual electric circuit

Q098U / 1062

BATH ORIGINAL

94, 95, 96 between the ¹¹ OE "gates 25r, 25g, 25t) and the actuators 26r, 26g, 26b added. In other respects the circuit according to Pig. 7 is to be regarded as unchanged and accordingly only the parts of interest are the modified embodiment in Fig. 13. The circuit of Fig. 11 can be used in connection with that of Fig. 13 and the terminals 31, 32, 34, 54 of Fig. 13 are connected to correspondingly numbered terminals of Fig is explained above.

The circuit according to FIG. 11 works essentially as described above, ie the operation of the relays 59, 69 is determined by the sequence in which the "OR" gates 25r, 25g, 25b close from the "0" state change to the "1" state. When the time ratio controllers 94, 95, 96 are set to provide other than identical values of q / p, the sequence in which the red, green and blue light exposures are terminated is generally different from the sequence in which the Gates 25r, 25g, 25b change from the "0 ^M" state to the "1" state.

When the circuit of FIG. 11 is used in conjunction with the circuit of FIG. 13, the circuit becomes 11 in relation to the circuit design according to FIG. 14 (instead of with the circuit according to FIG. 12). In Fig. 14 are details of the potentiometers 29r, 29g, 29b and parts of the time ratio controller 94,

0098U / 1062

9 "5, 96 shown. In Fig. 11 it is further shown how certain of these components are controlled by motors 62 and 72.

In Pig. 14 it is shown that the potentiometer 29g can have two fixed resistors 97 »98. The setting of the exposure integral for the copy material of green light is produced by manual setting of the position of a sliding contact 99 on a variable resistor 100 in the time ratio controller 95 of the green exposure control terminal. The resistor 43g in the controller 95 corresponds to the resistor 43 according to FIG. 10. When according to FIG. 14 the variable resistor 100 has a maximum value R ^ qq, then the portion ^ »which is brought into the circuit by the sliding contact 99 is yR ^ Q. This resistance st and y R. corresponds to the resistance 45 in Pig. 10. By adjusting vp, the duration of the green exposure can be adjusted to the value at which the required amount of magenta is produced in a copy after development. In the red exposure control channel, the controller 94 contains a variable resistor 106 of a maximum value ^E 106 "^ ^er ^ ^n-fcei ^ * P _r ^{of ß} 106" ^{which is} brought into the circuit by a sliding contact 105, the value can be changed by hand which produces the required amount of cyan color in a copy after development.

Similarly, in the controller 96 in the Blue light exposure control channel the proportion, ^ of a variable

0098U / 1062

Resistance 111 with maximum value R ..., that of the sliding contact 110 is selected, adjusted so that the required amount of yellow color in one copy is generated after the development.

When a series of copies is made, it moves. the motor 62 clockwise or counterclockwise, depending on whether the gate 25r changes from the "0" state to the "1 ^M state before or after the for 25g. The motor 62 is mechanically connected in such a way that it changes the 101 sliding across the winding dee moved potentiometer 29R. the 23r to the adder geliYerte reference voltage is determined by the proportion of the winding -Θ 102 which is selected by the contact 101. If during the exposure for a copy of the 25R from the ¹⁴ O "State changes to the" 1 "state after the for 25g, the relay 59 (Fig. 11) is energized to cause the motor 62 to rotate counterclockwise, thus decreasing the value of -Θ. During a subsequent copy causes the smaller ^w of ert · _Θ Γ that the trigger generated 24r an ^M 1 ^W signal, a smaller voltage is supplied from the integrator 22r. Accordingly, fore 25r and 25g operate in better timing, after a few dozen copies of substantially similar negatives have been made, a setting of & _{χ is} reached at which gates 25r and 25g operate substantially simultaneously. Then the direction of rotation of the

009814/1062

Motor 62 to, namely each subsequent negative or each subsequent group of negatives has been copied.

Similarly quietly, the motor 72 adjusts the portion $ _{b of} a winding 107 of the potentiometer 29b, which is selected by the sliding contact 106. The value of ^ is automatically adjusted to cause gate 25b to operate in substantial unison with gates 25r and 25g.

According to FIG. 14, the motor 62 is mechanically connected not only to the movable contact 101 of the potentiometer 29r but also to the movable contact 103 of the potentiometer 104 in the time ratio controller 94 for movement thereof. The contact 103 selects a component # _{r of} the total resistance R-jq4 ^ ^eB potentiometer 104. The resistor & _χ R ₁₀ ^ satisfied in the controller 94 the same 4? Wake as the resistor 43 in the circuit according to Fig. 10. Reference numeral with a small letter r in the controller 94 of Fig. 9 relate to components that are the same numbered components correspond to the circuit of FIG. Considering the time ratio controller 94 therefore can be seen that when the gate 25r for a time t in the ¹¹ O "state remains,

r *

the output of the controller 94 for a time t * in the "0" state remains, where

0098U / 1062

t «.

1 +

104

V ^R 104

= t.

104 *

However, t is given by

II

where V _{1 is} the reference voltage supplied by device 28r and A is a constant.
Accordingly, will

A.

1 + ψ r * ^R 106

III

From equation III it can be seen that the actual exposure time t ' _p for red light is independent of & _χ , but can be controlled by adjusting y.

Although by the action of the motor 62 the value of β

is adjusted to cause the corresponding time t is equal to t, during which the gate 25g is in the state "0 ^M, the motor 62 causes no direkfcrWirkung to the duration t _'r from the Eotlichtbelichtung.

The timing ratio controller 96 in the blue light control channel contains components 108 to 111 and 42 * b, 44b, 46b, 47b, 48b, which correspond to components 103 to 106 and 42r, 44r, 46r,

0098U / 1062

47? "or 48r of the controller 94 in the bot exposure control channel correspond. By exact same considerations it can be shown that the blue light exposure time t 'is given by

= CY,

b ' ^B 111
h09

IY

where V, the reference voltage provided by device 28b and C is a constant.

The motor 72 acts, that the time t _b, for which the gate 25b in the ¹¹ O "state, substantially equal to time t, or t is, in each of the longer of these.

Similarly, it can be seen that the green exposure time t ^{1 is} given by

g * ^R 100

43g

and therefore the same

B. V,

g ' ^B 100 ^l 43g

VI

From equations III, IV and VI it can be seen that the proportions of the times t ' _r , t ¹ and t' ^ for any negative by setting Ψ _x $

and

set

can be. Furthermore, the values of t ¹ , t ¹ and t'b »although the motors 62 and 71 act to the effect of essential equality ziriiohta t _w , Ί. and t _v auirechteu-

* m ■

00981Λ / 1062

obtained, not affected by this effect.

The circuit according to flg. 9 can also be combined with the circuit according to Pig. 8 are connected, and the terminals 31 'to 35' are connected to the terminals 31 to 35. The circuit according to FIG. 9 then acts as described above, with the exception that the calibrated ratios ty ¹ ^ ** ^ are not necessarily identical to the ratios of the exposure times t ¹ ft ¹ _α * ϊ \ . However, if ψ »« ^ _, ψ-u are not changed, the same purpose is fulfilled as before, ie it is prevented that the exposure times deviate from the previously established relationships by far more than predetermined proportions.

In addition, the following working methods can also be used adapted or used:

(i) A photoelectric integrator for "white light" is set to work faster than the integrators for electric light, green light and blue light. Separate time ratio controllers are used to create the different values of q / p and thus set different maximum time limits for t ¹ , t · and t ' _b , the exposure times for Eotlicht, Grtinlicht and blue light.

(Ii) As in (i), but the other three time ratio controllers become nia controllers used, over still line time limits to adjust.

0098U / 1062

(iii) In a simple method in which a dead-heat condition is assumed on an average negative, only a time ratio controller is used and a time interval t ends with the end of t _r , t or t _fe (as the case may be which ends first). At the end of t (1 + q / p) the other two exposures are ended.

(iv) In a modified embodiment of the invention the time ratio controller is a reversible counter that increments at a frequency and switching backwards step by step at a different frequency.

The embodiments described with reference to FIGS. 6 to 13 all relate to copier devices known type using temporary adjustment of the exposure of the copy material with regard to the red, green and blue light components, but the invention is equally applicable to other known types of copier, in which the intensities of the red, green and blue copy light correspond or mutual proportions are changed to their predetermined proportions of the intensity of the on the copy material of incident light, the exposure time being the same for all three colors. They are copiers described, in which the balance of hot,

0098U / 1062

Green and blue intensity is set by hand (Hunt,
J. Photographic Science, 11, pp. 117-120, 1963). Ea is
easy, of course, to provide servo control of the balance so that the adjustment is automatic, copiers of this type are in the US patent specification
3 161 108 (and in Gundelfinger, Taylor and Yanoey, in
Photographic Science and Engineering, 4, pp. 141-150, 1960).

In such variable intensity copiers, the proportions of EOT, green, and bulb light which reach the copy material are usually controlled to provide the proportion which, when evenly distributed over the copying area, will result in a copy that will be processed after development is gray. For practical reasons, copier devices of this type have so far found little acceptance. Accordingly, while it is to be understood that the invention is applicable to this type of copier, it is deemed unnecessary to explain more than the general principles in accordance with which the invention may be practiced in such copier. One embodiment of the invention in such a copier would provide means for limiting the movement of light modulating filters (or valves) so that limited correction could be made as soon as a new negative was presented into the copier gate, wherein

0098U / 1062

• However, the execution would be done in such a way that corrections beyond a certain extent only by a sequence of small increments could be obtained. For example, two complete sets of light modulators can be used are limited, one with quick response, however in the range to the required limit (e.g. -0.1 logarithmic units), and the other with only much slower addressing (for example 0.005 logarithmic units per copy circle run), however, with widely covered area (for example - 0.4 logarithmic units or more). The said limitation can be through limit switches, a combination of physical stops and sliding couplings or through any other known technique can be obtained. The slow response can be achieved through a suitable choice of the drive ratio from the motor to the light modulator larger area can be created.

0098U / 1062

Table ti comparison of various corrections?

Required
Correction in the

Tarb balance
a negative

ο, ο

- 0.070

- 0.130

- 0.175

Type of Subject

usual red κ green *

usual red s green χ

usual
red χ
green χ

usually
red χ
green χ

Copied d. Integration -to-gray (brit-r patent specification (660 099)

applied correct.

0.0

-0.300 +0.300

-0.070 -0.370 +0.230

-0.130 -0.430 +0.170

-0.175

-0.475

■ 1 + 0.125

Eest error

0.0

-0.300 +0.300

0.0

-0.300 +0.300

0.0

-0.300 +0.300

0.0

-0.300 +0.300

Error area

10,600

10,600

10,600

Copied with a correction factor of 0.7 (brit »patent specification 928 658 or 956 462

applied correct.

0.0

-0.210 +0.210

-0.049 -0.259 +0.161

-0.091 -0.301

+0.119

-0.1225 -0.3325 +0.0875

Eest error

0.0

-0.210
+0.210

+0.021
-0.189
+0.231

+0.039
-0.171
+0.249

+0.0525
-0.1575
+0.2625

Error area

10,420

0.420

10,420

10,420

Copied according to the Invention (limited to -

applied correct,

0.0

-0.130 +0.130

-0.070 -0.130 +0.130

-0.130 -0.130 +0.130

-0.130 -0.130 +0.125

Best mistake

0.0

-0.130 +0.130

0.0

-0.060 +0.200

0.0 0.0 +0.260

+0.045 +0.045 +0.300

Error area

10.260

10.260

»0.260 ι

)) O, 255

The color subject failure is believed to have had an increase of 0.3 the density of the color concerned is generated in the integrated optics.

cn co

K> CO

Claims (1)

Claims 1. Method for copying positives from a plurality of color negatives, characterized in that copying material is exposed to copying light via the negatives, which contains at least two color components, their intensities or their times of exposure of the copy material can be controlled to provide such color correction as copying is done with either fixed color correction or with a color correction in inverse proportion or in inverse proportion to the ratio the integrated transparency of the negative for light of the mentioned colors, copying with the fixed color correction is performed when the ratio by more than a predetermined proportion of a predetermined Value deviates, and is carried out with the inverse proportional value, if the stated ratio is not so differs, and that the selection of the type of color correction is caused by the color correction with the reverse Proportion is prevented when the ratio of the integrated permeabilities by more than the predetermined ^ ert deviates. 2o Automatic color negative copier in which the termination of exposure to copy light with each the three primary colors red, green and blue by a shutter (27) when responding to a photoelectric Control circuit is caused, which has a photocell (21), an integrator (22), a reference voltage (28), a potential 009814/1062 tiometer (29), a voltage adding device (23) and has a trigger circuit, the output of which is connected as an input to an "OR" gate, the output of which is connected to a Actuating member (26) is switched, which in turn is operatively connected to the closure (27), characterized by a time ratio controller (37), which is based on the output of the Triggeretromkreises (24) in a first photoelectric control circuit, one of the three Colors of the light corresponds, responds, the output of which as an input to the "OR" gate (25) in at least a second the light electrical control circuits are attached, and which is embodied as a device which, in response to a first and a second electrical pulse, a third electrical pulse is generated which follows the second pulse at a time in a controlled proportion to the time that elapses between the first and second pulses. 3. Device according to claim 2, characterized in that that the time ratio controller (37) has a current integrator (47, 48) with a voltage-sensitive trigger circuit (49) is connected, and a device (41 to 45) has to flow current of a first direction into the current integrator during the time that elapses between the receipt of the first and second pulse, and around Conduct current in the opposite direction during the time following the reception of the second pulse at least as long as until the output of the current integrator causes the 0098U / 1062 voltage-sensitive circuit generates the third pulse. 4. Apparatus according to claim 3, characterized in that the photoelectric control circuit controls the exposure terminated with blue light and the trigger circuit (24b) with means (51 to 53) connected to increase the predetermined value of the current in said first direction to reinforce. 5. Apparatus according to claim 4, characterized in that the time ratio controller is a reversible counter which switches stepwise forwards at one frequency and backwards stepwise at another frequency will. 6. Device according to one of claims 1 to 5, characterized in that in addition at least one further Time ratio controller (94 to 96) is provided which responds to the output of one of the "OR" gates (25r, 25gi, 25b), and the first or the second photoelectric control circuit and the output of the further time ratio controller with the singing of the actuating organ (26r, 26g or 26b) of the first or second photoelectric »control circuit is operatively connected. 7. Automatic color negative copier, in which the intensities of bot, green and blue copy light a light-modulated device are set to a predetermined proportion of incident on the copy material To evoke intensities, daduroh marked. 0098U / 1062 that the setting area that relates to a single Negatively created is limited to a range no more than 1/4 that of the modulator created area. 8. Apparatus according to claim 7 »characterized., that the light modulator device is a color selection filter is. 9. Apparatus according to claim 7 or 8, characterized in that the setting range by a limit switch is limited. 10. Apparatus according to claim 7 or 8, characterized in that the adjustment range by a combination a physical stop and a sliding clutch is limited. 0098U / 1062 Blank page