DE3426503A1 - Method of distinguishing between the front and rear of a developed film - Google Patents

Abstract

One side of a developed film (transparency) consists of an emulsion layer, and the other side of a base layer. The two layers have different water contents. The front and rear of the film can be distinguished from one another by altering the water content of the emulsion layer by heating or wetting of the film and detecting the state of curving, in particular the direction of curving, of the film after altering the water content.

Description

description

The invention relates to a method for distinguishing between the front and back of a developed Film, especially a framed film (slide).

Heretofore, to distinguish between the front and back of a developed film, an on the The figure applied or printed on the film was viewed, or the surface of the film was felt by hand. It is easy to make mistakes with these methods. In particular, it is difficult to find out exactly which one Page of a slide film in a frame inside an enlarger is arranged.

The invention is based on the task that the previously used procedures, uncertainties to be accepted when differentiating between front side and eliminate backside of a developed film by providing an improved process. The invention should be used in particular for the exact and simple determination of the relevant sides of a slide film will.

The solution to this problem is given in claim 1. In the method according to the invention, a developed film, which consists of an emulsion layer on one side of the film and a base layer on the other side of the film. The two layers have different water uptake, i.e. Water storage properties. The water content of the emulsion layer of the film is changed, and then

after changing the water content of the emulsion layer, the warpage state of the film is detected.

According to the method according to the invention, the respective Side of a slide film after its development simply and precisely determined by the fact that the state of curvature of the film after changing the water content is determined by a special detector device Makes use, which is described in more detail below.

In the following, exemplary embodiments of the invention are explained in more detail with reference to the drawing. Show it:

Fig. 1 is a sectional view of a portion of a developed film;

2A to 2C are sectional views of films in various States

Fig. 3 is a graph showing the relationship between the amount of bulges of various Films and the heating times of the films makes it clear

FIGS. 4A and 4B are schematic views of a system for distinguishing between the front and the rear a slide film,

FIG. 5 shows a sketch of a system in accordance with FIG. 4A

or 4B sensor used, and

FIG. 6 shows the characteristic curve of the sensor shown in FIG. 5.

Fig. 1 is a sectional view of a film 1 after it has been developed. The film consists of an emulsion layer 3 on which an image pattern is formed and a base layer 5. The emulsion layer 3 has a thickness x1 (i.e., a distance x1 from a face 2 of the film 1), and the base layer 5 has a thickness x2 (i.e. a distance x2 from a back side 4 of the film 1). The value x1 is about 20 to 27 µm, and the value of x2 is about 127 µm if a 135 mm reversal film is used. The emulsion layer 3 and the base layer 5 have different water absorption properties from each other, i. the water content of one layer is different from that of the other layer. The water content (or Moisture content) of the emulsion layer 3 is reduced by heating, so that the the emulsion layer The supporting side of the film shrinks, and consequently the state of the warpage of the film 1 against the state changes before heating the film. The decrease in the water content of the emulsion layer 3 of the film 1 after its development changes the state of warpage of the film so that the emulsion layer 3 shrinks, while an increase in the water content of the emulsion layer changes the warpage state of the film in such a way that that the emulsion layer expands. The respective side of the film 1 can thus be determined by the warpage state of the film is detected after changing the water content of the emulsion layer 3 of the film or investigated. In view of the circumstances set out above, the respective side of the film can be distinguished from the other side according to the invention by changing the water content of the emulsion layer, which forms one side of the film 1, the base layer 5 which forms the other side of the film 1, and through Detecting the state of warpage of the film

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by changing the water content of the emulsion layer 3.

Figs. 2A to 2C illustrate the buckling states of the film 1 according to FIG. 1.

Fig. 2A shows a film 1 in a flat state at room temperature. Will the water content of the emulsion layer 3 is reduced by, for example, heating the film 1, the film 1 bulges in a Direction corresponding to a shrinkage of the emulsion layer 3 of the film 1 shown in FIG. 2B. From this conclude that the surface of the shrunk side of the film is the face 2 of the Films 1 is. This is done by using the curvature brought about by shrinkage of a sensor. The film 1 thereby returns to the flat state shown in FIG. 2C, by stopping the heating of the film 1 and leaving the film at room temperature. An enlargement of the film (making prints) or projecting the film on a screen can be carried out after the side distinction has taken place.

Although reference has been made in the above description to a situation in which a film 1 is at room temperature assumes a flat state, the invention can also be applied to the case that a film 1 is not flat at room temperature, as will be described below with reference to FIGS. 3 to 6.

Fig. 3 shows characteristic curves of the states of curvature of various reversal films when these with the help of a 30 watt tungsten lamp, placed 100 mm from the film.

Figs. 4A and 4B schematically show a film side discriminating device with a position sensor 11 for determining the position of the surface of a with a Frame M with mounted slide film 10.

The distance D_ between the surface of the film 10 held behind the frame M and the position of the sensor 11 is first determined with the aid of the position sensor 11. The determined distance data D _Q are input into a comparator 13 as a reference value. The slide film 10 is then heated with the aid of a heating device 12 which is arranged on the side of the slide film 10 opposite the sensor 11. After the film 10 has been heated for a certain time, a measured distance D ₁ between the position of the sensor 11 and the surface of the heated film 10 is input to the comparator 13, where this value is compared with the distance Dq previously input as a reference value. By comparing the distances D ₁ and D 1, information about the state of curvature of the film 10 is obtained. This enables the side of the slide film 10 facing the sensor to be determined exactly.

Referring to Fig. 5, the position sensor 11 includes a light emitting element 11A such as a light emitting diode and a photosensitive member 11B such as a photodiode, which are both in one piece, i.e. on a common carrier, and arranged parallel to one another, see above that the light emitted from the light emitting element 11A is reflected on the surface of the slide film 10 and the photosensitive member 11B Will be received. If the position sensor 10 is located relatively far away from the film 10, then from the light emitting element 11A is a relatively weak one Light on the film surface, and that from this film

Surface reflected light is not appreciably emitted from the photosensitive member 11B receive. Accordingly, the output signal PS of the photosensitive device becomes rather weak in level Elements 11B received.

On the other hand, when the distance D between the position sensor 11 and the surface of the slide film 10 becomes small, so the amount of reflected light, i.e. the amount of light received, increases. If the distance D is further reduced, the light emitted from the light emitting element 11A is only applied to a region projected onto the film surface, that of the light-emitting Facing element, and the light reflected from the film surface is hardly received, so that the level of the output signal PS of the photosensitive member 11B gradually decreases.

Fig. 6 is a graph showing the relationship between the distance D between the film surface and the position sensor on the one hand and the level of the output signal PS of the photosensitive element 11B. According to 6, the distance D is obtained by first determining the characteristic shown in the figure and detects the level of the output signal PS.

As can be seen from the above description, in the operation of the system, the characteristic of a position sensor 11 to be used is first determined in advance, and the sensor 11 is arranged at a suitable position at a distance from the surface of a film 10 carried by a frame M, for example with a Distance D ₀ , so that the right section from the tip of the characteristic curve according to FIG. 6 is used. If, in this state, the film 10 from one of the

Sensor 11 located opposite side of the film heater is heated, the film 10 bends in one direction, so that the distance D increases or decreases compared to the original distance D. For example, if the original distance shown in FIG. 6 D is _Q and the film 10 bends in the direction shown in FIG. 4B when the film is heated with the heater 12, the 2Q distance D between the sensor 11 and the film surface becomes D that is, the distance is shortened compared to the distance D _Q.

The sensor 11 then generates an output signal PS, ■ Lg which corresponds to _{the distance D 1.} This signal has a level which is greater than the output signal PS «which corresponds to _{the distance D Q.} By detecting the change in the output level of the signals PS _Q to PS _{1, it} can be determined that the film 10 has warped toward the sensor 11 by the heating of the film. If, on the other hand, the film 10 bends in the direction of the heating device 12, this is determined on the basis of the fact that the distance D increases up to a distance D _? (see Fig. 6). and the sensor 11 generates an output signal PS "which is smaller than the signal PS, ..

According to the invention, the respective side of the Determine slide films by making the increase or

oQ the decrease in the level of the output signal from the sensor 11 compared to the output signal PS-. determined, whereby this output signal PS "corresponds to a state, in which the position sensor 11 assumes the position shown in FIG. 4A and the slide film 10 does not

gc is heated. If it is determined that the level of the Output signal PS is obtained by heating the film 10

_{increased from PS n} to PS ₁ while reducing the water content of the emulsion layer of the film, this means that the rear side of the film 10 faces the position sensor 11. If, on the other hand, the level of the output signal PS _{decreases from PS Q} to PS ~, this means that the front side of the film 10 is opposite the position sensor 11. It goes without saying, however, that the opposite relationships apply if the original distance D _{n is set} to the left-hand side of the characteristic curve with respect to the tip of the characteristic curve.

In a modified embodiment of the invention For example, a halogen lamp can be used as the heater, and a film heater can be used instead of a film heater use a film dryer, e.g. a blower. Of course you can make the distinction between the front and back of the film also make it possible that the water content of the Emulsion layer of the film increased. Another position sensor can also be used to determine the direction of curvature of the film can be used as the one described above.

Claims (4)

KLUNKER -SCHMrTC-NILSQN- HIRSCH ^: EL ¹ ROPEAMnTKNTATR) RNR ¹ S K21673 / 6 3426503 July 18, 1984 Fuji Photo Film Co., Ltd. Method of distinguishing between Front and back of a developed Films Priority: July 19, 1983 Japan No. 131691/1983 (patent application) Claims \ 1_yProcedure to distinguish between front side and back of a developed film characterized by the following steps: Preparing a developed film consisting of a layer of emulsion on one side of the film and a base layer on the other side of the film, both layers being different Have water absorption properties, changing the water content of the emulsion layer of the Films, and Detecting a state of warpage of the film after changing the water content of the emulsion layer of the Films. 2. The method according to claim 1, characterized in that the film to reduce the water content of the Emulsion layer is heated. 3. The method according to claim 1 or 2, characterized Fig. 5 shows that the film is dried to reduce the water content of the emulsion layer. 4. The method according to claim 1, characterized in that the film is wetted to the water content of the 10 to increase emulsion layer.