JPH0527604U - Photoelectric switch for measuring paper thickness, moisture, etc. - Google Patents

Abstract

(57) [Summary] [Purpose] To provide a photoelectric switch used for measuring paper thickness, water content, etc. that is free of paper dust and the like. [Structure] The photoelectric switch 1 is sealed with an aluminum cover 2, and a transparent, non-chargeable plastic film 5 is attached to the surfaces of the light projecting portion 3 and the light receiving portion 4 of the photoelectric switch 1 on the other hand. .

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a photoelectric switch for measuring instruments such as paper thickness and moisture, which is capable of performing stable scanning of the measuring instrument without adhering paper dust.

[0002]

[Prior Art]

 A paper thickness and moisture measuring device (hereinafter referred to as B / M meter) 21 repeats a reciprocating motion along a frame 22 mounted at right angles to the traveling direction of the paper S as shown in FIGS. 2 and 3. Scanning, and light such as visible light or infrared light is projected from the light projecting portion of the photoelectric switch 23 attached to the B / M meter onto the measurement object (sheet surface such as paper) S, and The reflected light is detected by the light receiving portion of the photoelectric switch 23 (reflection type). In addition to the reflective type, the photoelectric switch includes a type that senses an object to be measured by sensing a change in the amount of projected light with a light receiving unit (transmissive type or retroreflective type).

The photoelectric switch of the B / M meter in the papermaking process, etc., has two photoelectric switches 23a and 23b attached at appropriate intervals, and one switch 23a can be used to change the position of one side edge of the paper. When the B / M meter is sensed, the B / M meter is scanned in the direction perpendicular to the paper running direction (ie, the width direction), and when the other end is reached, the other photoelectric switch 23b senses the position of the other end of the paper and moves in the opposite direction. The scanning is performed, and while repeating this, the scanning is continuously performed in the width direction of the paper.

[0004]

[Problems to be solved by the device]

 Since the B / M meter measures the thickness of the running paper or the water content online, the paper dust adheres. On the other hand, since the B / M meter also continuously scans, static electricity is generated, and paper dust easily adheres to the B / M meter. In this case, if paper dust adheres to the surface of the photoelectric switch, the amount of reflected light from the light receiving section becomes weak, and the photoelectric switch cannot detect the edge of the paper.

For example, if paper dust adheres to the photoelectric switch in front of which the B / M meter is scanning, the photoelectric switch cannot detect the edge of the paper, and the B / M meter detects an unspecified portion of the paper. There is a drawback that the paper is scanned in the reverse direction, and the thickness and moisture of the portion of the paper positioned ahead of it cannot be measured.

The present invention has been proposed in order to solve such a drawback, and an object thereof is to provide a photoelectric switch in which paper dust does not adhere to the photoelectric switch of the B / M meter.

[0007]

[Means for Solving the Problems]

 According to the present invention, in a B / M meter, the photoelectric switch of the B / M meter is sealed by an aluminum cover, and the light projecting portion and the light receiving surface of the photoelectric switch are transparent and non-chargeable. The structure is such that it is covered with a plastic film.

[0008]

[Action]

 The present invention is constructed as described above, and since the aluminum cover is grounded, static electricity does not occur. Further, since the light emitting surface and the light receiving surface of the photoelectric switch are covered with a non-charging and transparent plastic film, there is no possibility that paper dust adheres to the light emitting surface and the light receiving surface. As the transparent and non-electrically conductive plastic film, for example, a non-chargeable polyethylene film such as IC Pack manufactured by 3M under the trade name can be used. Incidentally, the B / M meter in the present invention can be used as it is.

Therefore, the photoelectric switch does not adhere to any paper dust even when the paper is running, especially the paper running at high speed, and the B / M meter continuously and continuously scans the entire scanning range. Since there is no unmeasured area, the B / M meter can stably measure the thickness, moisture, etc. over the entire width of the paper.

[0010]

【Example】

 FIG. 1 shows an embodiment of the present invention. Next, the structure and operation of the present invention will be specifically described with reference to FIG. The photoelectric switch 1 is covered with an aluminum cover 2, and the surface of the light projecting portion 3 and the light receiving portion 4 located below the photoelectric switch 1 is transparent and non-chargeable. The plastic film 5 is attached.

That is, in the present invention, the photoelectric switch 1 is sealed by the aluminum cover, and there is no possibility of static electricity being generated. On the other hand, since the transparent and non-chargeable plastic film 5 is attached to the light projecting section 3 and the light receiving section 4 of the photoelectric switch 1, there is a risk that paper dust may adhere to the light projecting section 3 and the light receiving section 4. Therefore, the B / M meter does not reverse scan from the middle during scanning, and the B / M meter can always be stably scanned.

[0012]

[Effect of the device]

 As described above, according to the present invention, since the paper powder does not adhere to the photoelectric switch, the B / M meter can be constantly and stably scanned for a long period of time, and the workability is good, and the measurement failure of the B / M meter is poor. There is no danger of causing.

[Brief description of drawings]

FIG. 1 is a perspective view of an embodiment of the present invention.

FIG. 2 is a perspective view of a B / M meter and a frame.

FIG. 3 is an enlarged perspective view of a B / M meter.

[Explanation of symbols]

 1: Photoelectric switch 2: Aluminum plate 3: Light emitting part 4: Light receiving part 5: Plastic film

Claims (1)

[Scope of utility model registration request] 1. A measuring instrument for paper thickness, moisture, etc., wherein the photoelectric switch of the measuring instrument is sealed by an aluminum cover, and the light projecting portion and the light receiving portion of the photoelectric switch are transparent, and Photoelectric switch for measuring paper thickness, moisture, etc., which is covered with a non-static plastic film.