Film developing apparatus

A film developing apparatus includes an exposure section for effecting a standard exposure on a photosensitive film under a predetermined condition in a manner similar to that for exposing a control strip. The apparatus further includes a transfer path for transferring the exposed film for development, a densitometer for measuring the density of the developed film, and a device for displaying the condition of the processing solution which is determined based on the measured density. The standard exposure is effected on an unexposed film which is specially provided for the standard exposure, or on a part of an ordinary film with which pictures has been taken. The plural conditions may be set for the density measurement and for the standard exposure. The film developing apparatus is provided with a sensor for detecting the kind of a film to be exposed, and for selecting conditions based on the kind of the film.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The present invention relates to an apparatus for developing a photographic 
film, and more particularly to an improved film developing apparatus with 
which the condition of a developing solution is monitored for controlling 
the developing solution. 
2. Discussion of Related Art 
Conventional film developing apparatuses for developing photographic films 
include a developing section, a drying section, etc. Currently, so-called 
automatic developing apparatuses which include a CPU for controlling 
various. factors which affect the developing process are widely used. In 
the use of such automatic developing apparatuses, a developing solution 
must be controlled with the greatest care. 
Controlling of a processing solution in the film developing section is 
generally carried out by the use of a so-called control strip. The control 
strip is an undeveloped film which has predetermined reproductive 
characteristics and has been exposed to light under standard exposure 
conditions in which the intensity of light, exposure time and the 
characteristics of light are previously determined. After the control 
strip is developed, the density of the film is measured to determine the 
exhaustion degree of the developing solution. 
Since the control strip must be processed in dark, it is put in a dark box, 
called "control strip holder" in a darkroom. The control strip is then set 
in a receiving inlet of the developing section of a film developing 
apparatus together with a holder therefor. 
As described above, in conventional film developing apparatuses, 
controlling of developing solution is carried out based on the results 
obtained by developing the control strip housed in the control strip 
holder. However, the control strip holder involves drawbacks in that the 
mechanism for receiving the control strip is not simple due to the 
necessity of light-shielding, causing a troublesome operation for loading 
the control strip into the control strip holder. 
Moreover, at the time of setting a control strip holder in a film 
developing apparatus, complicated operation is required because of the 
requirement of complete shielding of light. For checking the condition of 
the developing solution, it is required to stop the general development 
processes, and then to set a control strip holder containing a control 
strip in the film processing apparatus. 
In many cases, however, developing solutions are controlled without the use 
of a control strip, because the loading of the control strip into the 
control strip holder and the setting of the control strip holder into the 
film developing apparatus are cumbersome, and the control strip must be 
specially prepared as a material for controlling the developing solution. 
In such cases, controlling of the developing solutions is carried out by a 
well-trained operator who intuitively determines the condition of the 
developing solution based on the frequency of processing, operation cycle 
time of the film developing apparatus, and the quality of the processed 
negative films. 
In such, there arise fears that a misjudgment of the operator may happen in 
controlling the developing solution, which will allow deteriorated 
developing. Further, hiring of well-trained operators is against the 
automation and simplification of processing. 
SUMMARY OF THE INVENTION 
An object of the present invention is to provide an improved film 
developing apparatus in which the developing solution can be controlled 
easily. 
Another object of the present invention is to provide an improved film 
developing apparatus with which the developing process is simplified, and 
the quality of developed materials is improved. 
Briefly, a film developing apparatus according to the present invention is 
characterized by including an exposure section for effecting a standard 
exposure under predetermined conditions, means for measuring the density 
of the film after development, and means for indicating the condition of 
the developing solution based on the data of measured density. 
Here, explanation is given to the "standard exposure". Conventionally, an 
undeveloped film which has been exposed under predetermined conditions 
(intensity of light, exposure time and characteristics of light) is used 
as a control strip. The control strip is passed through a developing 
solution for determining the condition of the developing solution based on 
the color developed. The exposure effected under such predetermined 
conditions to provide a control strip is called "standard exposure". In 
the present invention, a standard exposure is effected in the exposure 
section provided in the film developing apparatus. 
According to the present invention, since the standard exposure can be 
effected in the exposure section of the film developing apparatus to 
prepare a "substitute" control strip for conventional control strips, 
troublesome works involved in loading of a control strip into a control 
strip holder and setting of the control strip holder to the film 
developing apparatus can be eliminated, by which easy checking and 
indicating of the condition of the developing solution is achieved. 
Moreover, since the developing solution is automatically controlled, a 
stable quality of developing can be secured. Furthermore, since it is not 
necessary to keep special materials for controlling developing solutions, 
processing of films can be simplified.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
The present invention will now be described with reference to the 
accompanying drawings. FIG. 1 is a schematic sectional view showing a film 
developing apparatus according to a first embodiment of the present 
invention. The film developing apparatus is mainly composed of an exposure 
section 1, a developing section 2, a density measurement section 3, a 
control section 6 and a monitor 7. The film developing apparatus is 
provided with an ordinary film inlet 16 through which an ordinary film is 
inserted. A plurality of guide rollers 17 are disposed in the film 
developing apparatus for transferring the inserted ordinary film 5 to the 
developing section 2 and then to the density measurement section 3. 
A magazine 15 is mounted on the exposure section 1 for holding a film 
cartridge loaded with an unexposed film 4. The unexposed film 4 is 
transferred to the developing section 2 via the exposure section 1. 
Numeral 18 denotes a sensor for reading a DX code on the film cartridge 
which indicates the kind of the unexposed film 4. A lamp 11 and a shutter 
12 are disposed in the exposure section 1 for exposing the unexposed film 
4. A cutter 13 is also disposed in the exposure section 1 for cutting the 
unexposed film 4 into a predetermined length. Further, a densitometer 14 
is disposed in the density measurement section 3. 
In the exposure section 1, the unexposed film 4 pulled out from the 
magazine 15 is exposed to a light beam from the lamp 11 under 
predetermined standard exposure conditions when shutter 12 is opened. The 
lamp 11 and the shutter 12 are controlled by the control section 6 for 
effecting a standard exposure on the unexposed film 4. The exposure forms 
a test pattern including a transparent area, a gray area and a black area 
on the film 4. The film 4 is then transferred, by the rollers 17 without 
using a leader for transferring, to the developing section 2, in which the 
film 4 is developed. The film 4 is then transferred to the density 
measurement section 3 in which the density of the film 4 is measured by 
the densitometer 14 so as to obtain the density of each of the three 
primary colors in the transparent area, gray area and black area of the 
test pattern formed on the film 4. 
The DX code printed on the cartridge is read by the sensor 18, and then fed 
to the control section 6. The control section 6 calculates with regard to 
the condition of the processing solution for each kind of the film 4. The 
measured values of density are displayed on the monitor 7 together with 
data indicating whether or not the condition of the processing solution is 
in a predetermined usable range. 
The ordinary film 5 which has been used as housed in a camera for taking 
pictures is inserted into the ordinary film inlet 16. In this case, the 
shutter 12 is not opened, and the film 5 is transferred to the developing 
section 2 via the exposure section 1. In the developing section, an 
ordinary developing is taken place. 
FIG. 2 is a sectional cross section showing a second embodiment of the film 
developing apparatus according to the present invention. In the drawing, 
sections and components which are the same as those in the first 
embodiment are denoted by the same reference numbers. 
In the second embodiment, a film for undergoing standard exposure as used 
in the first embodiment is not utilized. 
An ordinary film which has been used as housed in a camera for taking 
pictures is fed to the exposure section 1, in which the leading end or 
tailing end of the ordinary film 5 is exposed to a light beam from the 
lamp 11 under the standard exposure conditions when the shutter 12 is 
opened. Similar to the first embodiment, the lamp 11 and the shutter 12 
are controlled by the control section 6 for obtaining the standard 
conditions. 
The film 5 is then transferred by the rollers 17 without using a leader for 
transferring to the developing section 2, in which the film 5 is 
developed. The film 5 is then transferred to the density measurement 
section 3 in which the density of the film 4 is measured by the 
densitometer 14. The DX code printed on the cartridge of the film 5 is 
read by the sensor 18, and is then fed to the control section 6. The 
control section 6 calculates with regard to the condition of the 
processing solution for each kind of the film 5. The measured values are 
displayed on the monitor 7 together with data indicating whether or not 
the condition of the processing solution is in a predetermined usable 
range. 
FIG. 3 is an explanatory illustration of a display for monitoring the 
condition of the developing solution used in the film developing 
apparatuses shown in FIGS. 1 and 2. As FIG. 3 shows, the display presents 
information concerning the upper limits and lower limits of densities for 
the primary three colors, measured density values for each color and 
information indicating whether or not the processing solution currently 
used is still usable. 
In the first embodiment shown in FIG. 1, the film 4 is transferred along a 
transfer path as shown in FIGS. 4 and 5. In the drawings, numeral 8 denote 
a transfer path for the film 4, numeral 9 denotes a path for the ordinary 
film 5, numeral 25 denotes rollers and numeral 26 denotes sprockets. As 
described above, the film 4 which is a "substitute" control strip is 
transferred by roller 25 along the path 8 disposed parallel to the path 9 
for ordinary film 5. This arrangement allows the film 4 to be exposed and 
developed even when the ordinary film 5 is developed. 
FIG. 6 is an explanatory chart showing an example of the light source used 
in the exposure sections of the film developing apparatuses according to 
the embodiments. In the drawing, numeral 10 denotes a sensor, numeral 11 
denotes the lamp, numeral 20 denotes a light controlling filter, numeral 
21 denotes a control section, numeral 22 denotes a mechanical shutter, 
numeral 23 denotes a filter drive section, numeral 24 denotes a shutter 
actuation section. The quantity of light and the color temperature are 
detected by the sensor 10, upon which the control section 21 automatically 
controls the voltage applied to the lamp 11, and the light controlling 
filters 20 in accordance with the kind of the film detected by the sensor 
18. The light controlling filters 20 are YMC color filters, and they are 
advanced or retracted to control the color of the exposure light. 
FIG. 7 is a block diagram showing an example of the control section 6 used 
in the film developing apparatuses according to the embodiments. The 
control section 6 includes functional blocks for controlling the exposure 
conditions for effecting a standard exposure in response to signals which 
are output from a timer at predetermined intervals or to input signals 
which are output from a keyboard at arbitrary timings. The control section 
6 also includes functional blocks for controlling the transferring of the 
films, and functional blocks for calculating the condition of the 
processing solution based on data output from the densitometer 14 and for 
displaying the condition. 
FIG. 8 is a flowchart showing the operation of the film developing 
apparatuses according to the embodiments. 
In cases where a signal is not output from the timer or the keyboard, the 
processes in steps 101, 102 and 103 are repeated for carrying out ordinary 
developing. 
Whenever it is detected in step 100 that a signal is output from the timer 
at predetermined timings, the process moves from step 100 to step 104 for 
automatically carrying out a standard exposure. After the detection of the 
kind of a film in step 104, the exposure conditions for the standard 
exposure, such as, the intensity of light and exposure time are adjusted 
and confirmed in steps 105 through 109. It is to be noted that plural sets 
of exposure conditions corresponding to kinds of films are memorized in a 
memory (not illustrated) of a CPU, and suitable exposure conditions are 
selected at step 104. Subsequently, a standard exposure is effected on the 
film (namely, unexposed film 4 or ordinary film 5) in step 110. 
After the film is developed, the density of the film is measured in step 
111, and the condition of the processing solution is calculated based on 
the density. It is to be noted that plural sets of measurement conditions 
corresponding to kinds of films are memorized in the memory (not 
illustrated) of the CPU, and suitable measurement conditions are used in 
step 111. Information indicating the condition of the solution is then 
displayed on the monitor 7 as shown in FIG. 3. After that, it is 
determined in step 112 whether or not the condition of the processing 
solution is within a predetermined usable range. When it is judged that 
the condition is within the predetermined usable range, "OK" is displayed 
on the monitor 7 in step 113. On the contrary, when it is judged that the 
condition is outside the predetermined usable range, "NG" is displayed on 
the monitor 7 in step 114. In this case, the transferring of the film for 
processing is stopped in step 115 for preventing ordinary films from being 
developed in deteriorated conditions, thereby maintaining the quality of 
the developing. 
In the above-described embodiments, a standard exposure and determination 
of the condition of the processing solution are carried out at 
predetermined intervals. However, they may be carried out after every 
predetermined number of processing of ordinary films. Further, the film 
developing apparatus may be Controlled such that it is stopped if the 
standard exposure and the determination of the condition of the processing 
solution has not been carried out for a predetermined period of time. As 
indicated by the broken line in FIG. 8, the operation of the control 
section 6 may be modified in such a way that the developing procedure is 
automatically stopped after elapse of predetermined period of time, 
without checking the condition of the processing solution. 
Obviously, numerous modifications and variations of the present invention 
are possible in light of the above teachings. It is therefore to be 
understood that within the scope of the appended claims, the present 
invention may be practiced otherwise than as specifically described 
herein.