JPH03216652A - Film detector for automatic developing machine - Google Patents

Abstract

PURPOSE:To improve film detecting accuracy by setting a reflection type photoelectric sensor so that the optical axis of projected light may be turned to be within a specified angle range in a direction opposite to a film feeding direction with respect to the surface of a feeding roller near a generatrix where a film starts to contact. CONSTITUTION:The optical axis of the projected light of the sensor 2 can be turned at >0 deg. and <=15 deg. in the direction opposite to the film F feeding direction from the position of the sensor 2 where an incident angle is 0 deg. with respect to the film feeding roller 1 near the generatrix of the roller 1 where the film F starts to contact with the roller 1. Therefore, the sensor 2 stably and surely projects and receives the light while the film F is passing and the reflected light is hardly received because the roller 1 is irradiated when the film passes. Thus, the detecting accuracy is enhanced.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to means for detecting a film in a film discharge section of an automatic processor.

[Conventional technology]

Detection of a jam before the exit of an automatic processor is important, and in the case of poor detection, it is not possible to quickly stop the subsequent film and save the jam, resulting in a great deal of damage. Therefore, we considered the selection of detection means and how to utilize this detection means. Film transport is often carried out by supporting rollers or between rollers.Especially at the exit of an automatic processor, the film transport direction often changes significantly, and here the film is supported between opposing rollers. There is. Therefore, by taking advantage of the fact that the movement of the leading edge or trailing edge of the film is regulated, and by providing a film detecting means in this area, the detection can be ensured. There is a mechanical method of detection using a microswitch actuator, but the drying at the exit of the automatic developing machine may not be sufficient and contact with the actuator may cause scratches or jams. It's inappropriate. Therefore, a non-contact detection means is required, and a photoelectric sensor is suitable for improving detection accuracy. However, the detection accuracy of photoelectric sensors also varies depending on how they are used, and the angle at which the light is applied is an important factor in increasing detection accuracy and quickly stopping film transport.

(Problems to be Solved by the Invention) It is an object of the present invention to improve film detection accuracy, quickly and reliably stop film conveyance upon detection of a jam, and rescue subsequent films.

[Means to solve the problem]

The purpose of this is to move a reflective photoelectric sensor facing the film transport roller from a position where the incident angle θ'' to the roller surface is near the generatrix of contact between the film and the film transport roller. This is achieved by a film detector in an automatic processor, which is installed in a direction opposite to the film transport direction and rotated within an angle of <15 degrees from θ''.

〔Example〕

The incident angle is 0 with respect to the roller ■ near the generatrix of the roller L where the film F starts contacting the film transport roller L.
The light emitting axis of the sensor 2 is moved from the position of the sensor 2 at 06<15
It is designed to be able to rotate within 6 degrees. In this way, while the film F is passing, the light reception of the sensor 2 is stabilized and the film is passing I;
Almost no reflected light from the rays irradiated onto the sensor was received, thus improving detection accuracy. Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a side sectional view of an automatic processor to which the film detector of the present invention is applied. The exposed film is at the left entrance A.
The film enters the film in the direction of the arrow, passes through various processes while being conveyed to the right, reaches the drying section 4 in the lower right, is checked by a film detector (sensor) 2, and is discharged into a film basket 3 in the direction of the arrow. . Here, the processed film F is dried in the drying section 4 and then reaches the film detector (sensor) 2, but since it is not completely solidified, avoid rubbing the surface with a fixed object. There must be. Therefore, a reflective photoelectric sensor was provided away from the film path and aimed at the film surface to form the film detector (sensor) 2.

FIG. 2 is a side cross-sectional view explaining the drying section 4 in more detail. The roller 1 rotates in the direction of the arrow, and the film that comes down from above passes in front of the film detector (sensor) 2, and the roller 1 rotates in the direction of the arrow. Rollers 5 and 6 roll facing each other.
and guide 7 to change the direction of the film basket 3
going into.

FIG. 3 is a side sectional view showing the position of the film detector (sensor) 2 in detail, and shows a perpendicular line OP drawn from the center O of the roller 1 to the contact start line when the 7 film F contacts and passes the roller 1. An experiment was conducted to find the optimum value for the angle B formed between the extension line and the light emitting optical axis of the photoelectric sensor. The data is shown in FIG. The rotation angle of the light emitting axis of the photoelectric sensor is 15', 13°, 12', ll'. 8.5°. 7.5'
, 0.5" and 7 types, and replacing the sensor 2 with the same performance with 57, S8, 99, 510, and Sll, and looking at the difference in light reception level for each, as shown in the figure. 5' to l3'' showed reliable differentiation with respect to the threshold level, and favorable good results were obtained. In this test, since the film detector would come into contact with the upper guide roller 8 if the angle exceeded 15 degrees, the rotation angle was checked within a range of less than 15 degrees. The optimum practical value in this test is 7.5° to 13°. However, even in the range exceeding 0° to 7.5" and the range exceeding 13° to +5', the threshold range is significantly lower than in the case of vertical illumination, which has been used in the past. It can be said that the significance is high and it is within the practical range.

Therefore, in order to improve the detection accuracy, the rotation angle of the light emitting axis with respect to the roller l must exceed θ° even slightly.
It can be said that it is necessary to keep it within °.

As described above, the amount of light received changes greatly at the moment the projector switches from receiving reflected light from the film surface to receiving reflected light from the roller surface after the film has passed. If the change is large, the sensitivity of the film passage detection catch will be good and stable. And if the light emitting axis of sensor 2 rotates even slightly as in the present invention,
The reflected light from the film surface returns to the receiver without being significantly attenuated, but when the film passes through and the light is reflected from the roller surface, the angle of the reflective surface becomes larger than the previous film surface, so the light is reflected from the roller surface. This can be said to be because the reflected optical axis is wide apart from the incident optical axis, and the amount of light that enters the light receiver is eclipsed and becomes small. On the other hand, if the rotation angle exceeds 15 degrees, the amount of light reflected from the film surface will be eclipsed too much, making it difficult for the light to reach the photoreceptor, resulting in a decrease in sensitivity.

〔Effect of the invention〕

As shown by the above-mentioned experimental data, depending on the rotational position of the installed sensor of the present invention, the detection accuracy can be improved even with the same sensor, and the jam detection response can be made quickly and reliably, and even if troubles such as jams occur, countermeasures can be taken. can be transmitted quickly and easily.

[Brief explanation of drawings]

FIG. 1 is a side sectional view of the automatic developing machine. Figure 4 shows data showing the relationship between the sensor's angle of incidence and the level of light received. l...Roller 2...7 Film detector 3...Film basket 4...Drying section 5...Roller 6...Roller 7...Guide

Claims (1)

[Claims] A reflective photoelectric sensor facing the film transport roller directs the light emitting optical axis of the sensor in the film transport direction from a position where the incident angle is 0° with respect to the roller surface near the generatrix where the contact between the film and the film transport roller starts. in the opposite direction,
A film detector for an automatic processor, characterized in that the film detector is installed so as to be rotated at an angle greater than 0° and within 15°.