JPS6022652A - Method for deciding front/rear face of film - Google Patents

Abstract

PURPOSE:To decide the front/rear face of a film surely and easily by discriminating the curling direction of the film when the water content of an emulsion layer of the film is changed. CONSTITUTION:After a length D0 between a position sensor 11 and the film surface of a mount film 10 is measured at a room temperature by the sensor 11, a heater 12 arranged in the side opposite to the sensor 11 is used to heat the mount film 10 uniformly. After it is heated for a certain time, a length D1 between the sensor 11 and the surface of the film 10 is measured by the sensor 11, and the curling direction is discriminated in accordance with the result of comparison between lengths D1 and D0, and the front/rear face of the film 10 is decided on a basis of this decided result. That is, if a detection signal PS of the position sensor 11 is increased from a detection signal PS0 for the initial position to a detection signal PS1 by heating, the side of the position sensor 11 is the rear face of the film 10; and if the level of the detection signal PS is reduced to a detection signal PS2, it is judged that the front face of the mount film 10 is directed to the side of the sensor 11.

Description

[Detailed description of the invention] The present invention relates to a method for determining the front and back sides of a developed film.

Conventionally, the front and back sides of a film have been determined by looking at the numbers written on the film, or by touching the film directly with a child. For this reason, there is always uncertainty in determining whether a film is front or reverse, and it is particularly difficult to determine the front and back sides of a mount film (slide film) loaded in a mount. Therefore, an object of the present invention is to provide a method for reliably and easily determining whether a film is front or back.

This invention will be explained below.

By the way, as shown in FIG. 1, the developed film after development is at a distance #X+ (135n+
In the case of a reversal film of m, the distance from the emulsion layer 3 with the pattern to the back side 4 [2 (135 mm)
In the case of a glue parsal film, about 127 p, m) is the base layer 5, and the emulsion layer 3 and the base layer 5 have different characteristics. In particular, the water content characteristics are different, and the emulsion layer 3 can be heated, for example, by heating the film.
The moisture content of the film is lower than before heating, and the emulsion layer 3 side shrinks relatively, causing the film to curl! E changes. As described above, when the moisture content of the emulsion layer of the film after development is reduced, the curl of the film changes in the direction that the emulsion layer side shrinks. Conversely, when the water content 14 is increased, the emulsion layer side changes in the direction of expansion. In other words, in this invention, the moisture content of the emulsion layer of a film consisting of a base layer on one side and an emulsion layer on the other side is changed, and the front and back sides of the film are determined by the curling shape of the film. . Figures 2 (A) to (C) show how this change occurs. At room temperature, film 1 is flat (see Figure 2 (A)), and in this state, the emulsion layer of film 1 is flat. When the water content is reduced (for example, by heating the entire film 1), the curl state always changes in the direction in which the emulsion layer 3 side shrinks, as shown in FIG. Therefore, by detecting this curl state with a sensor, it can be determined that the surface that has shrunk due to the curl is the surface of the film 1.

Then, when reducing the water content of the emulsion layer (heating) is stopped, the film 1 absorbs moisture from the air through the curled shape 1 (Figure 2 (B)), and as shown in Figure 2 (C). )
Since the original flat state is returned as shown in FIG. 2, it is possible to perform printing, projection, etc. after front/back discrimination. The following is an explanation for the case where film 1 is flat at room temperature, but even if film 1 is curled at room temperature, I
) f-ability. According to experiments, changes in the curl state when various films 1 are heated are as shown in the characteristic diagram of FIG. 3. However, as a heating method, use a 30 mm tungsten lamp to heat approximately 100 mm from film 1. i
It was then lit.

Next, as shown in FIGS. 4(A') and 4(B), a method of determining the front and back sides of the mount film IO using the position sensor 11 that detects the position of the film surface will be described. First, the distance faDo between the mounting film 10 and the film surface is measured using the position sensor 11 at room temperature, and then, as shown in FIG. 4(B), using the heater 12 disposed on the opposite side, The mounting film 1o is heated to -. After heating for a certain period of time, the distance D1 between the sensor 11 and the film 1o is measured using the position sensor 11, and the direction of the curl is determined depending on whether the distance increases or decreases from the initial distance #:D0. From this result, it is determined whether the film io is front or back. Here, as shown in FIG. 5, the position sensor 11 has an integrated structure in which a light emitting element 11A such as a light emitting diode and a light receiving element 11B such as a photodiode are arranged side by side in the same direction. The light emitted from the film 11A is reflected by the film lO, and the reflected light is received by the light receiving element 118. Therefore, when the position sensor 11 and the film lO are far apart, the light fitting reaching the film surface is weak, and the reflected light does not reach the light receiving element 11B, the level of the output signal PS is small S, and the distance between the As the amount of light decreases, the amount of reflected light increases and the amount of light received also increases. When the distance between the position sensor 11 and the film 1O becomes further narrower, the irradiated light from the first light emitting element 11A hits only the film surface in the area facing the light emitting element 11B. The reflected light from the "-2 facing area is no longer received by the element 11B, and the output signal level PS from the light receiving element 11B also gradually decreases. Therefore, 1 position sensor 11 and mount I
・The relationship between the output signal PS of the light receiving element 11B and the distance to the film 10 is as shown in FIG. The distance @D to the mount film IO can be detected.

From the above, the position sensor 11 as shown in FIG.
Preliminarily determine the characteristics of the characteristic curve, and use the right side of the peak of this characteristic curve to set the distance #D to the film lO.
This state (position sensor 11
By heating the mounting film IO using the heater 12 with an output of PSo), the film curls and the spacing increases or decreases with respect to the initial value DO. Here, when the initial distance fa Do is at the characteristic curve position as shown in FIG. 6, when the roll 1 film 10 is curled in the direction shown in FIG. D1 becomes smaller than the initial value D0, and the output PS of the position sensor 11 increases to Psl. Therefore, based on such a change in the output PS of the position sensor 11, it can be determined that the mount film I has curled toward the position sensor 11.

In addition, the mounting film 10 is heated by the heater 12.
When the film curls toward the heater 12, the distance from the film surface detected by the position sensor 11 increases to, for example, D2, so the output PS of the position sensor 11 decreases to PS2. It can be determined that the curve has curled toward the heater 12 side. Therefore, by detecting whether the detection signal PS of the position sensor II increases or decreases from the initial value PSo due to the heating of the heater 12, it is determined which direction the front surface (or back surface) of the mounting film 10 is facing. Is possible. That is, when the detection signal PS of the position sensor 11 at the initial position increases as shown in PS in FIG. When the level of the detection signal PS decreases as shown by PS2 in FIG.
It can be determined that the camera is facing one side.

Note that if the first 00 is provided on the left side of the peak in the characteristic curve of FIG. 6, the relationship between the front and back will be opposite to that described above.

As described above, the method for determining front and back surfaces of the present invention has the advantage that the front and back sides of a film can be reliably and easily distinguished from the curling phenomenon caused by changing the water content of the emulsion layer of the film.

In addition, although the above explanation described an example in which a heater is used as a heating source, the method is not limited to a heater, and a method using a halogen lamp or the like or a method using dry air as a dehumidification source can also be used.

In addition to reducing the water content of the emulsion layer of the film, any method that can change the water content may be used, such as increasing the water content, such as using high-humidity air. Further, the position sensor for measuring the distance to the film surface is not limited to the above embodiment, and may be any sensor that can identify the direction of curl.

[Brief explanation of the drawing]

Figure 1 is a diagram showing an example of the structure of a developed film, Figure 2 (A
) to (C) are diagrams for detailed explanation of this invention, No. 3
The figure shows an example of the heating and film curl characteristics of the present invention, Figures 4 ('A) and (B) show an example of determining the front and back sides of the mounting film, and Figure 5 shows the measurement. FIG. 6 is a structural diagram showing an example of the position sensor used, and FIG. 6 is a diagram showing an example of the characteristics of the position sensor. DESCRIPTION OF SYMBOLS 1... Film, 2... Surface, 3... Emulsion layer, 4
... Back surface, 5... Base layer, IO... Mount film, 11... Position sensor, IIA... Light emitting element, 118... Light receiving element, 12... Heater. Applicant's agent Yuzo Yasugata 28

Claims (1)

[Claims] The front and back sides of the film are determined by the curling state of the film when the water content in the emulsion layer of the film is changed, one side being a base layer and the other mI being an emulsion layer. Method for determining sides.