DE1910048A1 - Method for indicating defects on the surface of a web and apparatus therefor - Google Patents

Description

DR. E. WIEGAND DIPL-ING. W. NIEMANN 1910048 DR. M. KÖHLER DIPL-ING. C. GERNHARDT MÖNCHEN HAMBURG TELEPHONE 555476 8000 MÖNCHEN 15, TELEGRAMS. KARPATENT NUSSBAUMSTRASSE 10

W. 14 041/68 13 / Loe February 27, 1969

Fuji Shashin Film Kabushiki Kaisha Kahagäwa (Japan)

Method for indicating imperfections on the surface of a web and apparatus therefor.

Summary;

Parallel rays are directed onto the surface of a web moving along a roller and the light reflected therefrom is caught to remove imperfections or imperfections on the surface of the Determine orbit. Semi-cylindrical lenses are used for the parallel alignment of the beams with each other and the focus used on the surface of the web.

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'ORIGINAL INSPECTED

The invention relates to a method for Displaying imperfections or imperfections on the surface of a web by optical means and on a device for this.

There have been generally three types of display devices for displaying defects on the Web both in the method of operation using reflected light and in the method of operation using transmitted light known »The three types are as follows: one type in which one Number of photoelectrically conductive elements arranged laterally in the vicinity of the advancing web are, a type known as the "flying spot method", in which a Point of light in the effective field of vision of a light Christian conductive ^ n element is scanned to produce a type known as "flying image method ") in which a part to be observed is uniformly illuminated and a part of the field of view is illuminated a photoelectrically conductive element corresponding point is scanned therein.

These facilities for viewing imperfections or errors are generally used for the delivery of imperfection signals to a automatic cutting device for cutting out and removing the cut-out part with the fault location or imperfection used. On the other hand, the devices described above for Applying markings to the web indicating the point of fault or imperfection on the web

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ORIGINAL

or to record the state of imperfection or fault location of the path used.

According to the invention, a semicylindrical lens is used for aligning the illuminating light beams in parallel with one another and also another semi-cylindrical lens for concentrating the parallel light rays on the observation part created the railway. The reflected rays of light from the surface of the web are emitted by a light source Conductive element displayed by means of a "traveling image process".

As described above, in the conventional traveling image method, a uniform one became Lighting applied to the web. Hence, a flaw or imperfection was made up by rays Illuminated in different directions and the rays of light from the imperfection that the photoelectric conductive element made up an extremely small proportion of the total Rays of imperfection. In terms of effectiveness and resolution, this was of big disadvantage.

According to the invention, an imperfection ^ or flaws on the moving web are illuminated with parallel beams of light, creating a high effectiveness and a good resolution can be achieved.

A primary object of the invention is to provide an improved method of curing efficiently

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of imperfections or flaws on the moving web, for example of bumps and scratches, which even extend parallel to the direction of advance of the web. Another object of the invention is to provide an effective device for indicating imperfections or defects on a moving web _e

The invention is explained below with reference to the drawing explained in more detail:

Fig. 1 shows a perspective view of an embodiment of the display device according to the invention.

Fig. 2 shows a perspective view of an example of a display device according to the previous one Technology.

Fig. 3 shows a perspective view of the main part of the display device according to the invention; and c /

FIG. 4 is a cross-sectional view of the main part of the display device shown in FIG. 3 according to the invention.

With reference to Fig. 1, which shows an embodiment according to the invention, the reference numeral 1 denotes a light source, for example a tungsten lamp including a linear filament. Reference numeral 2 denotes an infrared filter which is shown in

Should be used when the device is used to identify imperfections or faults

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on the surface of a photosensitive photographic film, and reference numeral 3 denotes a semi-cylindrical lens for the parallel alignment of the light beams emitted by the light source 1 with one another and irradiating the observation part 5 on the web 6 by the rays in the perpendicular direction to get this. The lens 3 can be a ball lens. The reference numeral 4 denotes a semicylindrical one Lens for concentrating the beams aligned in parallel by the semi-cylindrical lens 3 onto the surface of the web 6 in a wedge shape. The effect of the latter cylindrical lens 4 is with With reference to FIG. 4 explained in more detail. Numeral 7 denotes a roller for holding the web in predetermined Position and reference numeral 8 denotes a lens for concentrating the reflected parallel light rays from the observation part 5 to a mirror 1o that vibrates or oscillates will. The reference numeral 9 denotes a spherical lens for focusing the observation part 5 on the slot 14. 1o denotes an oscillating mirror for scanning the observation part 5 in accordance with FIG Field of view of the photoelectrically conductive element The oscillating mirror 1o is moved with the aid of a magnet 11 and a coil 12 is actuated.

The coil 12 is connected to an oscillator 13. According to the invention, the oscillating mirror oscillates at a frequency of e.g. 2oo cycles per second one embodiment. Accordingly, the field of view of the photoelectrically conductive element 15 moves the observation part of the surface of the web 6 with a

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} i: l η and Iior

Speed of 2oo times per second / l) _e r oscillating mirror 1o may be replaced by a rotating multi-faceted mirror, but in this case, a complicated device for achieving a good result, the illuminating light is required _p because once switched off at the end of the observation part 5 or at the end of the lenses 4 and 8 and accordingly a clamping device is required for wiping out the signal. The signal from the photoelectrically conductive element 15 is dureh. an amplifier 16 amplifies. The ¥ erstirlc © r is amplified by an amplifier, including a high-pass filter and an amplifier, a low pass filter including _g: formed to the signal of a sharp flaw or imperfection, such as scratches, the signal of a relatively weak flaw or Unvollkommeraieitj, S ₉ B ₃ 4ner to separate unevenness with a certain surface “This amplifier can indicate the two types of imperfections, as is well known, with different sensitivities. Reference numeral 17 denotes a discriminating circuit which transmits a signal to the safety circuit 18 when a signal having a strength greater than a certain level is applied to the input. The memory circuit 18 stores the signal until the web on the part with the defect indicated by the above-described device, which device comprises the circuit 17, is cut and operates a solenoid to remove the part with the detected defect or imperfection. On the other hand, the memory circuit 18 stores the signal until the part of the web with the fault location or

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Imperfection up to the point of marking arrives and actuates the marking solenoid.

With reference to Figures 2, 3 and 4 in which the particular feature of the invention is illustrated in greater detail where Fig. 2 shows a common lighting method represents »the observation part of the trajectory to be observed becomes uniform over a wide one Area illuminated with a lamp 19. When a flaw or imperfection 2o moves past, changes the light value of the light beam 21, which is directed onto the photoelectrically conductive element, however, the change in the light value is very small. This is due to the fact that the observed Part is illuminated from different directions.

¥ _e nn However supplied to the observation part of the path light rays are parallel to each other, as shown in Fig. 3, the shadow is caused by the fault location, _f apparently visible and the change of the light value of the light beams 21, which photoelectrically the Achieve conductive element is remarkable.

As shown in Fig. 4, by arranging the semi-cylindrical lens 4 so as to bring its focal point in front of the observation part 5, most of the light rays concentrated in a wedge shape are directed in the same direction as the surface of the observation part the track is curved along the cylindrical surface of the roller. In addition, the arrangement of the focal point of the cylindrical lens 4 on the roller 7 of the loading

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ORIGINAL INSPECTED

observation part 5 forms an elongated band with a certain width on the surface of the web, whereby most of the light rays applied to the observation part are effectively used. E ₃ is therefore not a non-uniformity of the display ode *? ' There is detection sensitivity, such as that caused by the lack of a scan between one scan and the next, and the light beams are effectively used. The latter feature is particularly advantageous for a web which it is desired to be free from exposure to light rays, such as for photographic materials

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ORIGINAL IHSPEGTED

Claims (9)

Claims 1) Werf Ahren for displaying mangling and imperfections on the surface of a web using the Wanderbildabtastverfahrens, characterized in that moving the web along the surface of a rotating roller, the light beams on the observed part of the B _a hn on the roll in parallel alignment with one another and perpendicular to the axis of rotation of the roll and intercepts the reflected light rays from the web surface. 2) Method according to claim 1, characterized in that the on the part of the surface to be observed light rays directed along the path are concentrated in a wedge shape. 3) Method * according to claim 1 or 2, characterized in that placing the concentrated end of the directed at the surface of the web light beams on the roller along which the web to be _T moves. 4) Device for displaying defects or imperfections on the surface of a web according to the method according to any one of claims 1 to 3, characterized in that it has a roller (7) for the Vorvorführung.der web on it, a light source (1) for the Directing light rays onto the surface of the path (6) moving along the roller ('T), a semi-cylindrical lens (3) which is placed between the light source (1) and the roller (T) for the parallel output 909837/1127 Direction of the light rays from the light source (1), which are directed onto the path (6) moving along the roller (7), an optical system (8, 9, Io and 14) for directing the reflected light rays from the surface dsf web (β) gu the method of any Wanderbildabtast "lichtelektriseh a conductive element (15). 5) Device according to claim 4, characterized in that the optical system is a semi-cylindrical Lens (8), which is arranged in the vicinity of the roller (7.) * for directing the reflected light beams on comprises an oscillating mirror (1o), the oscillating mirror (1o) for directing the reflected light = radiate through the semi-cylindrical lens © in a photoelectrically conductive element. "is * 9 0 9 8 3 7/1 12 7 'ORIGINAL INSPECTED- A4 L e r s e i t e