Process and apparatus for developing photographs

A process and apparatus for developing photographs is provided wherein photographic sensitive material is held in a holding frame. The sensitive material is soaked in a developing solution by positioning the holding frame in a development tank with its upper and lower end faces spaced with predetermined distances, preferably more than 10 millimeters, apart respectively from the upper and bottom surfaces of the development tank. Thereafter the position of the development tank is reversed up and down at predetermined times while the developing-out of the sensitive material is carried out.

BACKGROUND OF THE INVENTION 
The present invention relates to an improvement of a developing process of 
photographic materials such as photographic film, roll films, sheet films, 
photographic plates, photographic papers or the like. 
The purpose of this invention is to solve the problem of poor uniformity in 
development to be formed, at the time of the developing process, on the 
sensitive materials namely on the opposite marginal areas of roll films 
and other photographic materials placed especially close to the top and/or 
bottom of development tanks. 
For the above purpose the films are placed in the development tanks 
allowing spaces between the films and the top and/or bottom of the tanks 
in the course of the developing process. 
Such poor uniformity in development is classified mainly into two kinds, 
one which has cloud-like patterns over the surface of the photographic 
materials and the other has narrow strip-like patterns at the opposite 
marginal areas of the photographic materials. 
The formation of the former may be effectively prevented by sufficient 
agitation of the photographic materials for about 30 seconds at the 
beginning of developing process in a development tank, which treatment has 
been broadly employed in the current photographic development process. It 
has not been successful, however, to prevent the formation of the latter, 
narrow strip-like patterns, as the cause has not been found out. 
The inventors of the present invention tried to find out the causes of the 
strip-like patterns by carrying out many tests. The developing is usually 
carried out by shaking the development tank as soon as the photographic 
sensitive materials have been placed in the tank and sufficient developing 
solution has been poured into the tank to wholly submerge the materials in 
the solution. 
Thus, the photographic materials are exposed to the developing solution 
which flows upwardly and downwardly on the surface of the materials as a 
result of the shaking of the tank. Contrary to the above procedure, the 
inventors made an attempt to place the photographic materials supported on 
a holding frame into the tank already filled with the developing solution 
and then repeatedly move the holding frame to the bottom of the 
development tank. As the result of this attempt, it was found that the 
narrow strip-like patterns come out only in the downward marginal areas of 
the materials. 
From this, it was found that such poor uniformity in development is caused 
by the vortical flow of the developing solution in contact with the 
surface of the materials which has been generated as the solution is 
pushed or carried by the downward movement of the holding frame or the 
materials as the frame hits the bottom of the tank and rebounds. 
Essentially, the development advances more quickly when the contact of the 
developing solution with the photographic sensitive materials is active 
and, on the other hand, it becomes slow when the contact between the flow 
of developing solution and the photographic sensitive materials is less 
active. Thus, the poor uniformity is caused when the contact due to flow 
of the developing solution over the surface of the sensitive materials is 
not uniform. 
It was also found out that the vortex flow of developing solution exists 
only in a zone of constant height from the bottom of the tank -- usually 
10 to 25 millimeters. Therefore, uniform development of a sensitive 
material is expected if the placement of the material in this zone is 
avoided, or if a space of 10 to 25 millimeters is kept between the 
material and the bottom (and the top) of the tank during its reversing 
motion in the process of the development. 
SUMMARY OF THE INVENTION 
Accordingly, the present invention is aimed to provide a process of the 
uniform development of photographic sensitive materials so as to provide 
finished photographs with no developing marks due to poor uniformity of 
development. 
According to the present invention, there is provided a process of 
developing photographs comprising the steps of holding photographic 
sensitive materials in a holding framework, soaking the sensitive 
materials in developing solution by positioning the holding framework in a 
development tank with its upper and lower end faces spaced with 
predetermined distances, preferably more than 10 millimeters apart 
respectively from the upper and bottom inner surfaces of the development 
tank, and reversing the development tank up and down at predetermined 
times while the developing-out of the photographic sensitive materials is 
carried out and apparatus for effecting the above steps. 
The object of the present invention is to provide a highly improved process 
and apparatus for developing photographs which provide uniformly developed 
photographs entirely free of developing marks due to poor uniformity 
development, specifically the uniform photographs free of narrow striplike 
developing marks on the marginal side areas of the photographic sensitive 
materials which is moved upwardly and downwardly in a repeated manner 
while treated in a development tank and which side areas corresponding to 
the longitudinal opposite sides in case of roll films.

DESCRIPTION OF PREFERRED EMBODIMENTS OF THE INVENTION 
Preferred embodiments of an apparatus for carrying out the process of 
developing photographs according to the present invention will be 
described in detail with reference to the attached drawings. 
In FIG. 1, the reference numeral 1 indicates a small sized development tank 
having at its upper end an opening for supplying therethrough developing 
solution, the opening being closed in liquid tight manner by a cap 2 to 
enable the shaking or reversing motion of the tank 1 up and down. A film 
holding framework 3 is provided with two guide members 4 each made of a 
continuous wire formed circinately in a horizontal plane and a frame body 
5 for supporting the guide members. 
In the tank 1 there are disposed a lower spacer 6 and an upper spacer 6' to 
provide a required space 1 between the lower end of the framework and the 
bottom surface of the tank and also between the upper end of the framework 
and the upper surface of the tank perspectively. On the framework 3 are 
mounted photographic films 7 wound around the circinate spaces formed by 
the upper end lower guide members 4 of the framework. After disposing in 
turn the lower spacer 6, the framework 3 with photographic films 7 and the 
upper spacer 6' in stuck relation within the tank 1, the upper opening of 
the tank is closed by a cap 2 in liquid tight manner. Then, there is 
supplied through an inlet port of the cap 2 a required amount of 
developing solution sufficient to submerge the whole portion of the 
framework 3 and the photographic films mounted thereon, and thereafter the 
inlet port is closed in liquid tight manner. 
While developing the films 7 (photographic sensitive material), the 
development tank 1 is repeatedly reversed up and down at required times, 
and, preferably a shaking motion is added to the tank while the tank 
reversed up and down. 
The spacers 6 and 6' as shown in FIG. 2 are formed of cross-like thin 
plates and each has a height of about 10 to 25 millimeters sufficient to 
keep the film free from the vortex flow of developing solution which will 
be generated when the tank is reversed up and down. 
The height of the spacers 6 and 6' may be more than that specified above, 
but since higher spacers cause an increase in the volume of the tank 1 was 
to require a greater amount of developing solution than would otherwise be 
used, the height of the spacers 6 and 6' is suggested to be limited to the 
above value from the economical view point. Thus, by use of spacers 6 and 
6' the poor uniformity in development of the materials caused by the 
vortex flow of the developing solution is effectively eliminated. 
FIG. 3 is to show a different form of the spacers 6 and 6' and the frame 
body 5, in which the upper and lower spacers 6 and 6' are integrally 
formed with the framework 3 and includes a tubular member, the upper and 
lower extremities of which serve as the spacers. 
FIG. 4 is to show another different form of the spacers 6 and 6' in which 
they are integrally formed by the upwardly and downwardly angulated 
portions of the frame body 5 having a required length corresponding to 1 
in FIG. 1. The frame body 5 is made up of shaped multiple rod members with 
the lower and/or upper spacer being formed by three or four leg-like 
members projecting downwardly or upwardly, as the case may be, from the 
holding frame. 
Further varieties of the spacers 6 and 6' may be easily contemplated by 
those skilled in the same art. For example, the spacers's 6 and 6' may be 
formed of some projecting portions (not shown) integral with the upper 
and/or lower surface of the tank 1. 
FIG. 5 is to show a different form of the framework 3 which is specifically 
adapted for use of the development of sheet films or photographic papers. 
This form of framework 3 has an upper and lower rectangular frame members 
which are horizontally positioned and rigidly connected at their four 
corners by vertically extending strut members, which strut members forming 
the upper and lower spacers 6 and 6' at their opposite end portions 
projecting beyond rectangular frame members 5 and 5'. 
Between the upper and lower frame members 5 there are provided a plurality 
of vertical guide members 4' arranged at desired intervals, which vertical 
guide members being disposed over one pair of interfacing sides of the 
frame members 5 as seen in FIG. 5. 
Vertical slot-like spaces formed between the adjacent vertical guide 
members 5 are used to support sheet-like photographic sensitive materials 
(not shown) by passing the sensitive materials therethrough while the 
development of the same processed. 
As may be understood from the above descriptions the present invention 
provides an improved process for developing out photographs on 
photographic sensitive materials. It provides the finished negative plates 
free of developing marks due to poor uniformity in development by means of 
simple apparatus in a simple and easy operation. 
FIG. 6 is a diagram to show a comparison of the uniformities of the 
development obtained by the present invention and by the prior art. The 
abscissa of the diagram indicates the distance from the upper side 
downwardly acrossing the width of the film, and the vertical coodinate 
indicates the density of the development. The curve A shows the plotted 
densities of the developed material when processed in accordance with the 
present invention, while the curve B shows those when processed in 
accordance with the prior art. 
As seen from the two curves of FIG. 6, in accordance with the present 
invention there could be obtained a much more uniform developing-out of 
photographs all over a photographic sensitive material as compared with 
that of the prior art. Therefore, successive treatments such as fixation 
for finishing photographs may be carried out in much easier operations 
thereby producing photographs of better quality than those by the prior 
art.