Control tool for and a method of calibrating a photographic processor and photographic printer

A control tool and method for calibrating a photographic printer and a photographic processor. The tool comprises an exposed unprocessed photographic filmstrip having a first image section for use in calibrating a photographic printer and a second image section for use in calibrating a photographic processor with respect to a predetermined aim. The first image section comprises a plurality of exposures of the same image, each image having a different exposure level, and the second image section comprising a plurality of density patches, each having a different exposure level. The exposed tool is developed so to determine the exposure levels. The exposure levels are compared with predetermined aims. The tool is printed if the measured data is within prescribed limits, or the film processor is adjusted in accordance with corrective measures if the measured data is outside said prescribed limits.

FIELD OF THE INVENTION 
The present invention is directed to a tool for monitoring and controlling 
a photographic processor and photographic printer in a typical processing 
facility or laboratory. 
BACKGROUND OF THE INVENTION 
A typical wholesale photofinishing lab or facility currently use monitoring 
systems which are fragmented, costly, technically cumbersome and not 
representative of the specific operation parameters or customers/markets 
served by the photofinishing laboratory or facility. 
Current monitoring systems for monitoring film processors and printers in a 
typical photofinishing facility are done daily, but in separate non-linked 
steps. A film processor is typically monitored through the use of a film 
process tool, which comprises an exposed strip of film which contains a 
plurality of patches of varying densities. Once the exposures have been 
developed, the density of the patches are measured and compared to aims. 
Deviations from the aim indicate if the chemicals are performing as 
required. If measured densities vary beyond predetermined parameters, 
corrective action is typically taken. Though the standards established may 
well represent technically well derived aims, they usually bear little 
similarity to the equipment, chemistry, or the configuration that exists 
in the particular lab environment. 
Currently there exists an array of printer setup and printer balancing kits 
available from various film manufacturers and other quality tool 
suppliers, most, if not all, embody a set of processed negatives and 
various common film types in a standard or referenced print for setup 
comparison. A typical printer setup tool comprises calibrated negatives 
that when printed or matched to aims to determine correct output. 
Particularly, each negative has an area for measuring the print density, 
which is compared to aim. Printer setups are changed to make prints at the 
aimed density by making adjustments to exposure to compensate for the 
deviation from aim. Printer setup tools may be processed by the 
manufacturer or by the photofinishing lab depending upon the type of tool 
being used. Since tools are being provided by the manufacturer, the setup 
obtained by the tool may not be representative of current film coatings 
processed through the processing lab, or may be printed on paper stock 
which is different from the one currently used in the photofinishing lab 
and prepared on a printer and processor, not some other system being set 
up for control. 
In addition to the foregoing problems, in a typical photofinishing lab the 
film process condition is not monitored at the time of processing the 
printer setup tool. Thus, the printer setup may be different due to film 
processing chemical conditions. It is important to be sure that film 
process chemical conditions are satisfactory at the time of the process of 
the printer control tool. Further, negatives from two different film 
process chemicals may require different printer setups even though both 
process chemicals are within limits. A further problem with the prior art 
printer control tool is that it is typically processed by the manufacturer 
and there is no link between the process chemical control tool and the 
processing chemicals of the customer films. As a result, printer setups 
always need compensation to produce the best color pictures. 
The present invention provides a single control tool that has process 
monitor patches and printer setup negatives. The photofinishing lab can 
process the tool, and if the process monitor patch densities are within 
specification, the photofinisher knows that the printer setup negatives 
are within the specification and will adjust the printing equipment 
utilizing the tool. However, if the patches used to monitor the film 
processor indicates that there is a problem, the tool will not be used and 
adjustments are first made to the film processor until the densities of 
the tool are within limits, then the portion of the tool used for printer 
setup can be used for setting up of the printer. Thus, utilizing the 
present invention, the user will know that the film process chemicals are 
within prescribed limits and that the printer setup negative have also 
been processed properly. The present invention also assures the 
photofinisher that the tool he is using matches the customer film and at 
the exact time of processing the film process chemicals will perform as 
required. This is a significant advantage because photoprocessing chemical 
performance can be altered by small amounts of contamination, differences 
in processing time, or temperature, thus requiring frequent monitoring. 
The present invention provides a printer setup tool every time the 
photoprocessing chemicals are monitored providing the ability for the 
photofinisher to eliminate the photoprocess chemical variation from the 
variation color and density of the customer pictures. 
SUMMARY OF THE INVENTION 
The present invention is directed to overcoming one or more of the problems 
set forth above. Briefly summarized according to one aspect of the present 
invention, there is provided a control tool for use in calibrating a 
photographic printer and a photographic processor. The tool comprises an 
exposed unprocessed photographic filmstrip having a first image section 
for use in calibrating a photographic printer and a second image section 
for use in calibrating a photographic processor with respect to a 
predetermined aim. The first image section comprises a plurality of 
exposures of the same image, each image having a different exposure level, 
and the second image section comprising a plurality of density patches, 
each having a different exposure level. 
In accordance with another aspect of the present invention, there is 
provided a method of calibrating a photographic processor and a 
photographic printer which uses the photographic material from the 
photographic processor. 
The method comprises steps of: 
a) providing an exposed unprocessed photographic filmstrip having a first 
image section for use in calibrating a photographic printer and a second 
image section for use in calibrating a photographic processor with respect 
to a predetermined aim, the first image section comprising a plurality of 
exposures of the same image, each having a different exposure level, the 
second image section comprising a plurality of density patches, each 
having a different exposure level; 
b) processing the exposed processed photographic filmstrip in the 
processor; 
c) measuring the developed photographic film so to determine the exposure 
level; 
d) comparing the measured exposure levels with respect to predetermined 
aims; and 
e) printing the processed photographic film if the measured data is within 
prescribed limits or adjusting the film processor in accordance with 
corrective measures provided for the measured data if the measured data is 
outside said prescribed limits. 
The above, and other objects, advantages and novel features of the present 
invention will become more apparent from the accompanying detailed 
description thereof when considered in conjunction with the following 
drawings.

DETAILED DESCRIPTION OF THE INVENTION 
Referring to FIG. 1, there is illustrated monitor control tool 10 made in 
accordance with the present invention. The tool comprises an exposed 
undeveloped strip of photosensitive material. In the particular embodiment 
illustrated, the photosensitive material comprises a negative filmstrip. 
The tool 10 comprises a plurality of density patches 12,13,14,15,16. The 
density of the patches 12-16 after the tool 10 has been processed is 
measured using a transmission densitometer and the measurements obtained 
are used for control plotting or diagnosis of the process conditions. If 
the process conditions are not within prescribed limits, corrective 
actions are taken. The density of the patches 12-16 are selected to make 
the film sensitive to specific process chemical conditions that would 
require adjustments. This technology is well known to those of ordinary 
skill in the art and is currently practiced throughout the industry. In 
the particular embodiment illustrated, density patches 12-16 are D-max, 
D-min, low density, high density and yellow. Density aims will vary upon 
the application. 
Example of aim status and densities are: 
##STR1## 
______________________________________ 
Yellow 0.90 R 1.50 G 3.20 B +/-.30 (Y) 
D-max 2.05 R 2.50 G 3.10 B +/-.30 
High density 
1.40 R 1.90 G 2.33 B +/-.30 (HD) 
Low density 
0.50 R 1.00 G 1.25 B +/-.30 (LD) 
D-min 0.20 R 0.64 G 0.90 +/-.30 
______________________________________ 
Status M densities are used in the following way: 
______________________________________ 
Aim Color 
tolerance 
Action limits 
Control limits 
balance 
______________________________________ 
D-min +/-0.03 +0.03 +0.05 NA 
LD +/-0.04 +/-0.07 +/-0.08 NA 
HD-LD +/-0.03 +/-0.07 +/-0.09 0.09 
D-max(b) - Y(b) 
+/-0.07 +/-0.10 +0.12 NA 
______________________________________ 
After the densities are recorded and computations made, each resulting 
value is plotted on a graph that compares the result to the aim, the 
process control limit and the process action limit. Graphic results are 
compared to limits and if any limits are exceeded, corrective action must 
be taken. What action to take can be determined using a manual that has 
the instructions for the specific chemicals being monitored. 
Definitions: 
D-max--the highest density area on a specific film process monitor tool. 
D-min--lowest densities measured on the process tool. This area is similar 
to an area that has not been exposed. 
HD (high density)--the higher status M density of two areas used for 
calculating film contrast performance in tested chemicals. 
LD (low density)--the lower status M density of two areas used for 
calculating film contrast performance in tested chemicals. 
Y (yellow)--a patch which has mostly yellow exposure which results in very 
high blue density and low densities in the red and green, for calculation 
of processing chemical performance on high density areas of the film. 
Stop (f stop)--one stop is equal to doubling exposure or cutting the 
exposure in half. A negative, which is one stop over-exposed, received 
double the exposure of a "normal" exposed negative. A negative, which is 
one stop under exposed, received one half the exposure of a "normal" 
exposed negative. 
Typical printer setup filmstrips use a single scene exposed in an exposure 
series ranging from 2 stops under to 3 stops over and sometimes as high as 
5 stops over (positions 20,22,24, and 26 on tool 10). These negatives are 
printed and the resulting prints need to match an aim to verify the 
printer will produce satisfactory prints from customer films. The "normal" 
frame is adjusted first by changing exposure relative to the "normal" film 
density. Over and under frames are adjusted using exposure compensations 
called "slope" which force the printer to make matched print densities of 
each of the scenes independent of the film exposure. Higher speed films in 
some applications may produce many more negatives with exposures greater 
than 3 stops over and require a printer setup tool which includes a 5 stop 
over-exposed frame for use in setting over slope. 
The tool 10 further includes scene images 20, 22, 24, 26, which are used 
for monitoring the printer setup and balance. The images 20, 22, 24 and 26 
all relate to a single scene having a series of exposures ranging from 2 
stops under to 3 stops over, and sometimes as high as 5 stops over. The 
images 20, 22, 24 and 26 are printed, and the resulting prints are matched 
to an aim to verify the printer will produce satisfying prints from the 
customer films. In the embodiment illustrated, the invention 20 comprises 
a scene composed of 3 individuals, each having a different reflective 
characteristic of their skin, posed with a background that is varying 
densities of non-selective color, for example, gray, and using digital 
transform process measuring patches, resolution patches and scene adjust 
patches. An example of simple images and methods which may be employed to 
produce such for images 20, 22, 24 and 26 are discussed in detail in U.S. 
Pat. No. 5,223,891 and U.S. Pat. No. 5,313,251, which are hereby 
incorporated by reference. It is to be understood that the scenes 20, 22, 
24 and 26 may be made by any appropriate method, however, the method 
disclosed in these patents have been found to be quite satisfactory and 
useful in producing a high quality, reliable tool. 
In order to more clearly understand the present invention, a brief 
description of its use will now be discussed. First, a tool 10, having the 
features described above, is obtained typically from a film manufacturer 
and then is run through a film processor wherein the images on the tool 10 
are developed. The appropriate measurements are made with a densitometer 
to determine if the film processor is within specification. If it is, the 
tool 10 is then sent onto the printer for printing, however, if the film 
processor is not within the prescribed specifications, appropriate 
corrective action as is well known to those skilled in the art is taken 
and another tool 10 is then passed through the processor until the density 
measurements obtained for the tool 10 are within prescribed limits. Once 
this occurs, the tool 10, having met all of the appropriate criteria for 
the film processor, is sent onto a printer where the images are printed 
onto a photosensitive media, for example, paper. The printed images are 
then compared with appropriate aims to determine if corrective action is 
required. If so, the appropriate action is taken as is customarily done in 
the field. 
The advantage of the present invention is that the tool 10, which is used 
to determine the printer setup, is processed in the same chemicals which 
the customer's negatives are to be produced by the operator. In addition, 
the monitoring is conducted at the same time at which the printer is being 
monitored. This is a significant advantage because photoprocessing 
chemical performance can be altered by small amounts of contamination, 
differences in processing time or temperature, thus requiring frequent 
monitoring. The present invention provides a printer setup tool every time 
the photoprocessing chemicals are monitored, providing the ability for a 
photofinisher to eliminate photoprocessing chemical variation from the 
variation in color and density of the customer pictures. Thus providing a 
more reliable and consistent product to the consumer. 
It is to be understood that various other changes and modifications may be 
made without departing from the scope of the present invention, the 
present invention being limited by the following claims. 
TS LIST 
10 Tool 
12-16 Patches 
20 Images 
22 Images 
24 Images 
26 Images