FI115490B - Camera lens washing device - Google Patents

Description

115490

Camera lens washer

The invention relates to the enclosure of a process control camera and to keeping the lens clean.

The object of the invention is to improve, for example, the image quality and reliability of a camera monitoring the operation of a paper machine.

The object of the present invention is to enable the surveillance camera to operate smoothly under conditions where the lens or its protective plate becomes dirty and difficult to clean. It is also an object that there is no momentary interference in the camera image, for example, when the wiper blades of the cleaning device pass by the camera lens.

Process surveillance cameras are usually enclosed in a window protective case. For example, in the vicinity of the paper machine coating station, there is airborne calcium-containing contamination 15 which permanently adheres to the lens shield. Normally the lens cover plate is kept clean by liquid jet cleaning and wiping, and compressed air can also be used for drying. A compressed air curtain is also used to reduce contamination, which is hoped to keep dirt away from the surface of the lens shield.

The problem with prior art is that if contamination is severe. If the lens is attached to or corrosive to the lens, it must be removed with a protective cover »·, very often cleaned, otherwise the surface of the lens will gradually become transparent-

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'\ a layer that cannot be removed at all. In this case, the shield should be washed practically all the time, or at least very often. In general, both mechanical abrasion and washing solution are required to remove aggressive particles.

• «*: When the lens cover of the camera is washed very often, the view of the lens is obscured for • · '··· at regular intervals using state-of-the-art washing methods. This masking needs to be taken into account in subsequent image processing and

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::: In this case some information is lost during washing. Therefore, it is not preferable to use: '*' to wash the lens cover of the camera lens used to describe the process. traditional windscreen wiper and liquid jet.

[. The invention is characterized by what is set forth in the characterizing part of the independent claims 1 to 6 and 6.

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According to the invention, the transparent plate serving as the protective plate of the process control camera lens is moved relative to the camera lens and the protective plate is washed outside the field of view of the camera lens, with a cleaned portion of the protective plate always in front of the camera lens. In this case, the lens cover plate can also be washed continuously without disturbing the imaging. In addition, the fouling and durability of the shield is improved because only a portion of the lens window is exposed to fouling, and most of the shield area is protected.

The following illustrates the operation of an embodiment by means of pictures.

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Fig. 1 is a plan view of an embodiment of the device according to the invention, seen from the front.

Figure 2 is a side view of the device of Figure 1.

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The principle of operation is best illustrated in Figure 1. It has a rotating transparent protective plate 3 housed in a housing 1 with a protective plate or housing cover in front thereof, and a lid 2 with a window opening at the lens of the camera. The transparent plate is thus protected from the outside except for the hole 2. The cover 20 in front of the protective plate 3 may also be transparent from the outside of the window, whereby the operation of the apparatus can be verified. from the outside. The diffused light entering the camera can be minimized on the inside with a black case. When cleaning, the protective plate 3 is rotated by means of axis 4, whereby • · • | the detergent syringe 5 and the wiper blade 6 clean the rotating transparent disk and the cleaned part of the disk returns to the front of the camera lens. Excess washing liquid and dirt: 25 run off drain pipe 7. Possible seals and means for removing dirty washing liquid are not shown in the diagram. The rotating plate is preferably sealed at its edges with, for example, a rubber lip, a textile seal or a foam rubber seal. If air cooling inside the camera housing is used, it is advisable to pressurize the housing with clean air to prevent even small amounts of dirt and dust from entering the camera housing. Also wet or oiled; ' · As a permanent seal or lip, it effectively prevents dust. The transparent panel with the '' compression is not very critical, because only to get dirty part of the camera on the potential / a protective plate 3, which is thus continuously washed with a cover plate cleansing and "> · / drying the wiper blade is preferably also acts as a seal against dirt camera 35... in the rotational direction of the lens, the post-lens portion is advantageously sealed only by a narrow gap 3 115490, since it is not advisable to scrub against the dirty shield with any seal or cleaning element prior to spraying the liquid.

5 The side view shows the structure of the housing and the camera washer. The camera 8 is housed in a closed housing, the transparent plate in front of the camera being rotated about the shaft 4 by a motor and a gearbox 9, if any. The front wall of the housing has a hole 2 which acts as a lens window. The shielding plate 3 can be cleaned continuously or intermittently. The rotation speed is not critical. Rotating too slowly will cause the protective plate to become dirty while you are in front of the camera lens, rotating too fast may cause water to splash, and drying or cleaning after the wiper may cause damage. The shield also wears when washing, so keep your rotation speed at a reasonable level. If the contamination is moderate, intermittent washing can also be used, for example every 5 minutes the engine and detergent spraying are started for a few seconds.

Because the device washes the shielding sheet 3 continuously and without disturbing the camera, if necessary, the device according to the invention is significantly better than the present scrubbers, especially under conditions of rapid and aggressive contamination. An example of a cumbersome location is a paper machine coating station in the vicinity. there is a significant amount of calcium in the air. This dirt adheres to the shield and · · also corrodes a normal glass shield. It is also an advantage of the invention that the shield • · * · · * wears much slower than the stationary shield that is washed in place. Only the currently exposed window area of the screen will get dirty, but the surface area of the screen is considerably larger. Thus, the abrasive effect of cleaning and dirt • * · · '·' spread over a larger surface area and thus the shield remains longer useful. Another advantage, for example, in the use of a safety camera, is that the part of the protective sheet which has been smeared with, for example, spray paint can be moved. t: After a moment, out of the lens to obtain an image of the subject, if any, • *>: ...: 30. In addition, the distribution of the washing liquid prior to wiping is easily improved by the current pressure, since the application of the washing liquid and the position of the wiping means relative to I ·: '*' remain constant. In addition, when using slow speed rotation speed • · »/. detergent life can be long without disturbing the camera image. Also great

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!., 'Use of spray is possible without affecting the lens cover * * ·

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35 pin to the transparency of the part seen by the camera. For example, in a paper mill, changing the protective sheeting causes a break in supervision, so it is advantageous if the changing sheeting sheet length is long.

The device can also be constructed to use a reciprocating linear motion. In this case, the transparent protective sheet 5 is preferably elongated and the washing means are preferably on both sides of the lens, whereby one end of the protective sheet is not washed. Any other configuration between the detergents and the shielding plate is also possible. In special situations, the transparent sheet may also be flexible, for example a thin polycarbonate sheet. This allows a compact design and also allows the bog 10 to be rollable on rollers. This would advantageously move the shield back and forth for cleaning, and when cleaning no longer results, for example due to scratching, the scratched portion is transferred to another roll. In this case, the used shielding sheet is preferably disposable. In this case, it is not necessary to use any cleaning of the shield, or it is also possible to settle for a disposable shield only. This solution is advantageous in the case where the lens shield is likely to be damaged frequently, but soiling is not very likely. An example of such a target could be a surveillance camera indoors, the fouling is very slow in normal use, but it would be important to get a shot through, for example, a spray-painted lens to capture the factors. In these 20 cases, often no reasonably priced washing machine would be able to clean. a disposable lens cover is a sensible solution. Cleaning equipment »·; however, it requires maintenance and it too would get dirty as a result of painting.

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Other possible configurations are provided by the washable or replaceable according to the invention; ; : 25-way lens protection is at least a rotatable cylindrical cap that rotates around the camera. The advantage of this design is that the compact enclosure has a large protective surface area of • · * ··· *, which allows a long wash time compared to that of the protective plate part in front of the camera lens.

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Claims (6)

An apparatus for keeping a window of a process control camera, for example, a surveillance camera lens of a paper machine coating station, (2) clean and protecting against rapid wear caused by aggressive contamination, wherein the device has a transparent that a part of the disc cleaned in front of the lens replaces the part of the contaminated plate, characterized in that the area outside the field of view of the camera is considerably larger than the area of the field of view 10 and the area outside the field is protected from contamination and wear. Device according to Claim 1, characterized in that the cleaning means 15 comprise at least a detergent injection apparatus. Device according to Claim 1, characterized in that the cleaning means include a wiper (6) for drying the transparent sheet from the detergent. Device according to Claim 3, characterized in that the detergent spraying apparatus is arranged so that the detergent has a long action time without interference of 'I> 1 in the camera image. * «» *: '; Device according to Claim 4, characterized in that the location between the detergent spraying apparatus and the detergent means remains the same, whereby the application of the detergent and the action time are easier to control. • I lit. 5, 115490 6. A method of controlling a process control camera, e.g., a papermaking machine ,,; for keeping the window (2) in front of the surveillance camera lens clean and protecting it from rapid wear caused by aggressive contamination, characterized in that a transparent protective plate (3) is rotated in front of the camera lens; past the stationary detergent injection device and mechanical cleaning means outside the field of view of the camera so that a portion of the contaminated disc is displaced; the cleaned portion of the plate in front of the lens and the area of the plate 35 outside the field of view of the camera is significantly larger than the 115490 area exposed to contamination in the field of view; > t »• c I i | 1 7 115490