Apparatus and method for laser scanner cleaning and protection

Abstract

An air guard directs air toward a viewing window of an optoelectronic presence sensing device to reduce surface contamination thereon. The air guard may include a control valve, and possibly control circuits, to enable selective activation of the air guard. In one embodiment, the air guard includes one or more slits configured to vent pressurized air in a generally laminar (curtain like) flow in front of the window to prevent the deposition of airborne contaminants thereon. Alternatively, or additionally, the air guard may include one or more nozzles configured to vent pressurized air in directed air streams toward the window to remove surface contaminants thereon, and may include a control valve enabling selective operation in preventive, cleaning, or standby modes. Mode control may be effected by an external control system, by the presence sensing device, or by the air guard itself, which may include a timer or other control circuit.

Description

BACKGROUND OF THE INVENTION [0001] The present invention generally relates to optoelectronic presence sensing devices, and particularly relates to the use of forced air systems to facilitate the maintenance and operation of such devices. [0002] Optoelectronic presence sensing devices find wide use in a variety of industrial applications. For example, one prevalent use arises in the context of “machine guarding,” wherein the object detection functionality of such presence sensing systems provides a triggering mechanism for shutting down hazardous machines before personnel get too close. Because of the safety-critical nature of this type of application, the installation, testing, and ongoing maintenance of such presence sensing systems represent vital functions. [0003] Other critical uses of such presence sensing systems include vehicle navigation and / or collision avoidance systems. For example, a shop floor forklift or other utility vehicle may be configured with one or more optical ...

AI Technical Summary

Benefits of technology

[0007] The present invention comprises a method and apparatus to reduce the surface contamination of a viewing window of an optoelectronic presence sensing device, such as the “scanning” window of a laser scanner as might be used in hazardous machine guarding applications or in object avoidance system applications. More particular, the present invention uses an air guard that is supplied with a source of pressurized air to vent air toward the viewing window to reduce the surface contamination thereof. The air guard may be configured such that it blows air across or in front of the window such that airborne contaminates generally are prevented from settling on the window. Additionally, or alternatively, the air guard may be configured such that it blows more focused and / or higher velocity air streams toward the viewing window toward the window surface to remove contaminants from the window's exterior surface. More generally, the air guard can be configured to direct air toward or across the window's surface in modulated (time varying) patterns and amplitudes as needed or desired.

[0008] Thus, according to an exemplary embodiment, an air guard for reducing surface contamination of a viewing window of an optoelectronic presence sensing device comprises a body section generally conforming to a contour of the viewing window, a first chamber formed within the body section and configured to receive pressurized air from an external source, and one or more first outlets in the body section configured to vent the pressurized air from the first chamber toward the viewing window to reduce surface contamination thereof. The body section may be integrated with the device housing of the presence sensing device, or may be affixed thereto, either permanently or removably. Indeed, air guards may be built as optional add-ons for particular models of presence sensing devices, or may be built into such devices.

[0009] In another exemplary embodiment, the present invention comprises an air guard for reducing surface contamination of a viewing window of an optoelectronic presence sensing device. The air guard comprises a body section generally conforming to a contour of the viewing window, first and second chambers formed within the body section, each configured to receive pressurized air from an external source, one or more slits formed in the body section and configured to vent pressurized air from the first chamber in a curtain like flow in front of the viewing window, and one or more nozzles formed in the body section and configured to vent pressurized air from the second chamber in one or more generally focused air streams directed toward the viewing window.

[0012] Regardless, an exemplary optoelectronic presence sensing system comprises an optoelectronic presence sensing unit configured to detect objects by emitting optical signals through a viewing window and detecting return reflection signals therefrom, and an air guard unit configured to direct air generally toward the viewing window of the optoelectronic presence sensing unit to reduce exterior surface contamination thereof. The air guard may be configured according to the previously mentioned exemplary details, and may be integrated with a housing of the optoelectronic presence sensing unit, or affixed thereto.

Problems solved by technology

Understandably, the operation of such devices can be compromised by the buildup of dust or other contamination on any device surfaces through which outgoing or reflected optical signals must pass.

For example, a given device typically uses one or more optically transparent “viewing” windows through which its optical signals are passed and any contamination of these windows can reduce device sensitivity and / or trigger the detection of a device fault.

Device faults can be costly because one or more production machines typically are tied in with a given presence sensing system, and these machines typically are automatically taken offline for the duration of any presence sensing fault condition.

As such, the buildup of contamination on the viewing windows of optoelectronic presence sensing devices raises a number of safety and efficiency issues in the typical manufacturing environment.

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