FR2601152A1 - Frame advance mechanism for exposure assembly of a device for printing photographic films - Google Patents

Abstract

Interchangeable frame advance mechanism for exposure assembly of a device for printing photographic films, interposed between a light source and the optical assembly, intended to receive and position frame by frame the negative film 33 to be printed, characterised in that it is composed: - of a support frame; - of a motor assembly 30; - of a primary drive member 7, 14 for the negative film; - of a film press 35 actuated when the frame is in place by an appropriate device; - of a secondary drive member 40; - of a device for limiting the advance 23 of the negative film to be printed, as a function of the format of this film.

Description

FILMS FOR EXPOSURE ASSEMBLY OF A DEVICE
DRAWING OF PHOTOGRAPHIC FILMS.

 The present invention relates to a film holder for an exposure assembly of a photographic film printing device. It also relates to the device for printing photographic films, in particular for simultaneous printing and development comprising such film holders.

In a known manner, a negative film printer is made up of several adjoining sets including in particular an exhibition set which essentially comprises in order
- a light source with filters
- a film holder, that is to say a device intended to position the negative film to be drawn
- an optical enlargement unit.

Currently known film holders which, more generally, operate manually and are often only film guides, the advance and positioning being done manually
In the French patent application of the applicant herself, application no. 85.04891, there is described a pass for 135 format films, comprising
- a base with two windows whose dimensions correspond to those of a view to be drawn
- a hinged cover on the base also having two windows superimposed on the windows of the base and having means for pressing the film to be pulled against the windows formed in the base
of a drive shaft for advancing the films, this shaft comprising two toothed rollers intended to mesh in the perforations formed on the edges of the film to be drawn on the one hand, on the other hand a disengageable drive jack and finally an operating head protruding from the base.

 This particularly simple device only applies to a particular type of film: the 135 format. In addition, when placing the film against the windows of the base, possible friction is always to be feared.

Finally, the braking system of the film with "felts" presents risks of scratches on the film, if these are not perfectly clean.
The invention overcomes these drawbacks. It offers a unique system of film film holders for an exposure assembly of a photographic film printing device, to be inserted between a light source and the optical assembly, intended to receive and position view by view the negative film to shoot
This feature is characterized in that it consists of:
- a support frame,
- a motor assembly consisting of a vertical axis, driven in rotation by means of a motor, the said axis being integral with a toothed pinion, itself being integral with a torque limiter
- a primary drive member for the negative film comprising
an axis parallel to the motor axis, supporting
a cylindrical roller of appreciable height
equal to the width of a negative film, and
presenting at the level of its two bases a
gear wheel intended to cooperate with
perforations in the nega film
tif, said axis being driven in rotation by
via a toothed pinion fixed on
this axis above said roller and which
cooperates with the toothed pinion of the motor axis
this axis also having a pulley soli
pair of a torque limiter, said pulley
being intended to receive a strap
training, and finally, it presents a
manual advance button located at its end
upper moth,
an axis parallel to the motor axis having
a crazy pressure roller, the same size
than the previous roll and building on
said previous roll under the action of
two springs fixed to the frame, and whose
application points are located above
and below said crazy roller
- a film press, activated when the view is in place by an appropriate device;
- a secondary training unit made up
on the one hand from an axis parallel to the motor axis
supporting a cylindrical roll of dimen
similar to the previous roll, said
axle with a pulley of light diameter
much lower than the previous pulley, and
intended to receive the said belt assu
rant thus its rotation,
on the other hand, from an axis parallel to the axis
motor supporting a mad pressure roller
same size as previous rolls
and building on the previous roll under
the action of two springs fixed to the frame, and
whose application points are located
respectively above and below said
roller
- a device for limiting the advance of the negative film, depending on the type of negative considered.

 In other words, the invention relates to an interchangeable passage having a drive device and a guide device, said guide device being driven via the drive device and this, in a concerted manner.

Advantageously, in practice
- the view position detection system is located within the support frame and is located at one of the perforations in one of the views of the negative film when it is in place
- the drive motor, the film press and the positioning detection system are electrically connected to a microprocessor
- the film press consists of a rigid plane frame, activated by means of two electromagnets
- the holder is completely removable and this, in a simple way.

 The manner in which the invention can be implemented and the advantages which ensue therefrom will emerge more clearly from the embodiment which follows, given by way of indication but not limitation, in support of the appended figures.

 Figure 1 is a three-quarter view of the device according to the invention.

 Figure 2 is a top view of the device according to the invention.

Referring to FIG. 1, the film holder according to the invention is inserted between the objective (38) of the color analysis device and the waveguide, from which the light beam comes, these two elements belonging the photographic film printing device. The film holder characteristic of the invention consists of a polycarbonate support frame
This film carrier first presents a motor assembly designated under the general reference (30). This motor assembly (30) firstly comprises a vertical axis (1) driven directly by a motor (3) electrically connected to a microprocessor (not shown). A toothed pinion (2) is integral with this axis (1). The toothed pinion (2) is itself: integral with a torque limiter (4) coaxial with said pinion (2). This torque limiter is intended to allow manual advancement, reversing, and framing of the desired view. The framing is displayed by the operator using the window (39), adjacent to the exposure head (36), and parallel to the negative film (33). The toothed pinion (2) is intended to cooperate with a toothed pinion - (6), integral with an axis (5) parallel to the drive axis (1). The axis 5) also has a cylindrical roller (7) rubberized with a height close to that of the negative film. In order to allow the adhesion of said negative film (33) on said roller (7), a pressure roller (14) parallel to the roller (7) and of dimension similar to the latter is applied against said roller (7) by means of two springs (16), materialized in FIG. 1 by arrows, fixed to the frame of the film carrier and the points of application of which are situated respectively above and below said roller (14) on the support axis (13) of said roll. The axis (5) also has above the toothed pinion (6) a pulley (9) integral with said axis (5), intended to receive a belt (10). This pulley is also integral with a torque limiter (11) coaxial with said pulley (9). The upper end of the axis (5) supports a manual feed wheel (12). This wheel (12) is intended to allow the advance or the retreat or even the framing of a shot.

 In a very similar manner, a secondary drive member bearing the general reference (40) also comprises a cylindrical rubberized roller (18), of dimension similar to the roller (7) and parallel to the latter, supported by an axis (17 ) and a pressure roller (21) supported by an axis (20) and applied against the roller (18) by means of two springs (22), materialized in FIG. 1 by means of two arrows, fixed to the frame of the pass -View and whose points of applicion are located respectively above and below the roller (21) on the axis (20).

The axis (17) also includes above the roller (18) a pulley (19) in which is housed the belt (10). Between the two assemblies, namely the motor assembly (30) and the guide assembly (40), a film press device noted (35) is fixed, it is intended to properly press the film and this, so completely coplanar in the training area. This film press consists of a rigid frame motorized by two electromagnets (not shown) pressing the film onto a fixed frame of the support frame
Thus, when it is desired to draw a negative film, the end of the negative film is firstly introduced manually between the two rollers (7) and (14) of the motor assembly. Using the thumb wheel (12), the film is advanced to the guide assembly (40) and the first view is framed. This manual advance is made possible thanks to the torque limiter (4 ) located on said drive shaft (1).

Thus, it is safe to carry out any manual adjustment without damaging the drive motor (3). The activation mechanism of the film press (35) is electrically connected to a microprocessor (not shown). Thus, the latter is applied to the film (33) only when the desired view is in place. This avoids any untimely friction of said film press.

 Once the first view is in place, the automatic printing device is switched on and the film is advanced automatically thanks to the microprocessor.

The motor (3) causes the axis (1), therefore the primary drive member (7,14) to rotate. In addition, due to the presence of the pulley (9), it also causes rotation through the belt (10) of the axis (17) and therefore of the roller (18) which is directly integral with it. Thus, the negative film (33) is directly driven on the one hand by the drive assembly (30) and on the other hand by the secondary drive member (40). It should be noted that the diameter of the roller (18) of the secondary drive member (40) is slightly greater than that of the roller (7) of the primary drive member. Also, the negative film (33) tends to be driven faster by the secondary drive member (40) than by the primary drive member (7,14). The negative film is thus thus always stretched. However, so as not to cause tearing of the negative film or stretching, the torque limiter (11) integral with the pulley (9) in a way allows self-regulation in slowing down the roller (18). The second torque limiter acts as a sort of mechanical advance regulator. In addition, when the film press is applied against the negative film (33), there is a slight recoil of the roller (18) without, however, the film slipping in the rollers (7,14) on the one hand, ( 18,21) on the other hand, always thanks to the help of this torque limiter.

When the penultimate view of the negative film is taken, it is the secondary drive member (40) which drives the film for the last exposure, then for the extraction, thus allowing the reprinting without turning the film.
When you want to shoot an entire negative film, only the manual framing of the first shot is necessary. Indeed, the film holder according to the invention -s e1up of a positioning system consisting on the one hand of a photoelectric cell (23), located on the motor shaft (3) of the motor assembly (30 ). Thus, for each type of negative film, the value cDCée in number of revolutions of the motor corresponds exactly to the length of a view of the negative film. This cell is electrically connected to a microprocessor (not shown) which causes the activation of the motor. (3)
This method solves the problem of advancing negatives of any format with the same device, as well as the problems of advancing calibration negatives.
All the elements constituting the film holder are easily interchangeable. Thus, if one of these elements is clouded, or has defects, it can easily be replaced. In addition, cleaning is greatly facilitated.

From the present invention, there are a number of advantages, namely
- dd due to the presence of torque limiters, there is no friction between the negative film, the negative film never slides on the rollers, which therefore prevents scratches and deformations
- always due to the torque limiters and the film press, the films are always stretched
- this system is universal for all roll films
- the detection system makes it possible to obtain framing of great rigor
- The detection device is relatively simple and therefore allows the realization of a very precise assembly without being expensive.

Claims (5)

 1 / Interchangeable film holder for exposure assembly of a photographic film printing device, inserted between a light source and the optical assembly, intended to receive and position the negative film (33) visually shoot, characterized in that it consists  - a support frame  - a motor assembly (30) consisting of a vertical axis (1) integral with a toothed pinion (2) and a torque limiter (4) integral with the toothed pinion (2), said drive axis (1) being driven in rotation by means of a motor proper (3)  - a primary training organ of the negative film comprising  an axis (5) parallel to the motor axis, suppor  as a cylindrical roller (7) in height  substantially equal to the width of the film born  gatif and presenting at the level of its two  two toothed wheel bases (8) intended for  cooperate with the perforations  within the negative film (33), said roller  (7) being driven in rotation by the inter  medial of a toothed pinion (2) integral  an axis (5) which cooperates with the pinion den  tee (2) of the drive shaft (1), the shaft  (5) further having a pulley (9) n / a  lid of a torque limiter (11), ladi  the pulley (9) being intended to receive a  drive belt (10), axis (5) pre  feeling moreover at its end a wheel  manual feed (12)  an axis (13) parallel to the two preceding axes  teeth and presenting a mad pressure roller  (14) of the same dimensions as the roller (7)  and resting on said roller (7) under  the action of two springs (16) fixed to the frame  of the film holder and whose application points  tion are located respectively above and  below said roller (14)  - a film press (35) activated only when the view is in place by an appropriate device  - a secondary drive member (40) consisting  on the one hand, an axis (17) parallel to the axes  previous and supporting a cylin roller  drique (18) of height similar to the height  said previous rollers, said axis (17)  further having a pulley (19), intended  born to receive said belt (10) ensuring  thus the rotation of the axis (17),  on the other hand, an axis (20) parallel to the  previous axes and supporting a roller  mad presser (21) of the same dimension as the  pressure roller (14), resting on the  roller (18) under the action of two springs  (22) fixed to the support frame of the film holder and  whose application points are located  respectively above and below the  said roller (21) on the axis (20)  - a device for limiting the advance (23) of the negative film to be printed, depending on the format of said film.  2 / Interchangeable film holder for exposure assembly of a photographic film printing device according to claim 1, characterized in that the detection and positioning assembly (23) of the views is located at the sight level. - even when it is in place.  3 / Interchangeable film holder for exposure assembly of a photographic film printing device according to claim 1 and 2, characterized in that the detection and positioning system (23) on the one hand, the motor (3 ) on the other hand, and the actuator of the film press (35) are connected to a microprocessor.  4 / Interchangeable film holder for exposure assembly of a photographic film printing device according to one of claims 1 to 3, characterized in that the film press (35) is constituted by a rigid and motorized frame at by means of two electromagnets  5 / interchangeable film holder for exposure assembly of a photographic film printing device according to one of claims 1 to 4, characterized in that all of the members constituting the film holder can be in contact with the film, or on the optical path of the drawing device are interchangeable.