CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of foreign priority to German Patent Application No. DE 10 2017 101 641.4, filed Jan. 27, 2017, which is incorporated by reference herein in its entirety for all purposes.

BACKGROUND

1. Field of the Invention

The following description relates to a wiping device for an optical device with a lens. For example, the lens may include a curved or calotte-shaped surface. The following description also relates to a rear view device for a motor vehicle including an optical device and such a wiping device.

2. Related Art

Optical devices with lenses, such as those used in rear view devices for motor vehicles in order to capture camera images of the area behind a motor vehicle, are exposed to environmental influences during operation. In particular, while driving the motor vehicle, such optical devices may become dirty. It is desirable for the lens to be as clean as possible so that the camera images obtained have a sufficiently high quality. A wiping device for cleaning such lens surfaces in rear view devices is described in United States Patent Application Publication No. 2007/0124886 A1. In the field of waterproof cameras, United States Patent Application Publication No. 2008/0170844 A1 describes wiping a protective pane placed in front of the lens using a wiping device. United States Patent Application Publication No. 2002/0139394 A1 also describes the cleaning of a shield for a lens using wiping elements. With the two latter devices, the surface to be wiped is essentially even. European Patent Application No. 2 792 556 A1 describes a wiping device for a surface of an optical element with a shape memory element. For example, this wiping device can be transferred to a different position when subjected to current or heat.

In addition, European Patent Application No. 2 933 155 A1 describes that a cleaning fluid can be included in a wiping element for an optical system. International Patent Application Publication No. WO 2005/039945 A1 describes a wiping element for a windshield which has a passage channel for water and a plurality of exit channels in order to guide the water from the passage channel to the windscreen.

Other wiping devices with fluid lines and fluid outlets are also known with the following additional features:

A wiper strip is described with two contact edges, and a liquid storage slot is formed between the two edges where a number of liquid outlets are formed at the bottom of the liquid storage slot so that the wiper strip can supply lubrication liquid while swinging. This is described in German Patent Application No. DE 11 2014 000 093 T5.

At least two washing nozzles are described which can be alternately coupled with a pump through switchable valves. This is described in German Patent Application No. DE 10 2010 054 687 A1.

A pivotally mounted wiper blade is described, where the position of the wiper blade relative to the glass surface determines the flow of washer fluid. This is described in United States Patent Application Publication No. 2011/0047738 A1.

A spray unit is described which sprays a cleaning medium close to a wiper strip on a vehicle window pane, where the cleaning medium is a liquid, compressed air or a mixture of both and/or the cleaning medium can be heated. This is described in German Patent Application No. DE 10 2008 042 405 A1.

Further, German Patent Application No. DE 10 2011 112 266 A1 describes a method and a control system for controlling a windscreen wiper and/or washing device of a motor vehicle, which has at least one wiper arm movably mounted at a window and at least one nozzle arranged to the wiper arm. The control unit is provided to execute at least two different wash programs for wetting the window with washing liquid in different ways. The control unit can be provided by signals from sensors, detectors, and the on-board electronics of the motor vehicle.

Sensors for detecting water or the like on a window pane of a motor vehicle are described in German Patent Application No. DE 195 26 249 A1. Depending on a rain intensity, the speed of the to and fro movement of a wiping element is increased or reduced. United States Patent Application Publication No. 2008/0088702 A1 describes the detection of dirt on a camera surface through monitoring of an optical test element with the aid of a test beam. According to European Patent Application Publication No. 2 792 555 A1, the movement of a wiper on a surface is monitored with the aid of a sensor.

SUMMARY

In an aspect, at least one object of the following description is to improve a way in which the quality of information is obtained via a lens for optical devices. In particular, an image quality of a camera which includes the lens can be improved. At least one object is to improve the conventional wiping device.

In an aspect, a wiping device for an optical device with a lens having a surface that is curved or calotte-shaped includes a wiping element for wiping the surface of the lens free from water and dirt particles, at least one passage channel, and at least one outlet channel which branches off from the passage channel in order to guide cleaning fluid onto the surface of the lens.

In another aspect, a rear view device for a motor vehicle includes an optical device and a wiping device as described above, where the optical device further includes a camera unit, and the lens is a part of the camera unit.

The wiping device may be provided for wiping the curved or calotte-shaped surface of the lens free from water and dirt particles. The wiping element may have a passage channel through which to transport cleaning fluid, and may further have at least one outlet channel which branches off from the passage channel, in order to guide the cleaning fluid onto the surface of the lens. Due to the supply of cleaning fluid during or before wiping, the wiping element can glide particularly well on the surface of the lens, and can also remove dirt particles particularly well. The invention thus in particular deviates from the idea as it was implemented in prior art, of providing an additional planar surface in front of lenses with curved or calotte-shaped surfaces, and instead, the curved or calotte-shaped surface is directly wiped itself. This enables a better image quality, since there is no covering on the lens.

The wiping element may have an inherent curvature which is adapted to the curved or calotte-shaped surface, and extends along the curvature. Due to the curvature of the wiping element, adapted to the curved or calotte-shaped surface of the lens, namely in particular with the same curvature radius, or merely a slightly larger curvature radius, the lens may be particularly well freed from water and dirt particles.

The wiping device may cooperate with means for supplying cleaning fluid, which includes a device for enabling and/or assisting the flow of cleaning fluid from a container and/or a supply channel, such as a domestic water installation into the passage channel. The device for enabling and/or assisting the flow of cleaning fluid may be, for example, a shut-off device. In particular, it may be a valve or a pump in the form of a dosage pump or it can include both. This device can be controlled or regulated by means of a control or regulation unit. Thus, the cleaning fluid does not have to be applied with each wipe, but can be supplied in a targeted manner, for example at the request of the user by actuating an actuation element. Preferably, a sensor element may be provided for acquiring measured values which allow a statement to be made regarding the degree of contamination and/or the type of contamination of the lens, where the sensor element is interconnected with the control or regulation unit and provides the unit with the measured values. The control or regulation unit may be designed to evaluate the measured values and in a first case to leave the wiping device inactive, and in a second, third, fourth and/or fifth case to set the wiping element in motion.

In the second case, the device for enabling and/or assisting the flow of cleaning fluid from the container may be triggered, or is not triggered, in such a way so that no cleaning fluid gets on the lens through the passage channel and the outlet channels. In a third case, the device is triggered in such a manner that cleaning fluid exclusively gets on the lens through the passage channel and the outlet channels. In a fourth case, the device is triggered in such a manner that water is pumped through the passage channel. In a fifth case, the device is triggered in such a manner that compressed air is pumped through the passage channel.

When using different cleaning fluids, a passage channel may be assigned to each cleaning fluid. In this way, it is not necessary to apply the additional cleaning fluid other than via the passage channel. In another example, the passage channels may meet in at least one outlet channel. In this manner, the fact that outlet channels are already provided which are connected to the first passage channel is exploited.

A plurality of outlet channels may be provided, in order to be able to apply cleaning fluid to the largest area possible on the curved or calotte-shaped surface of the lens.

The units may set the wiping element in an oscillating motion at least at times. In particular, this can be achieved via the device for supplying cleaning fluid, preferably when the wiping element has at least one elastic wiping lip, which in a further preferred manner takes the form of a rubber lip. The setting into an oscillating motion can be achieved through the use of at least one pneumatic cylinder or motor, although preferably the wiping element moves only by itself when the device for supplying cleaning fluid is triggered. This moving by itself can be based on the recoil principle can be used, for example, as is known from sprinkler systems. Springs can ensure a return movement. As an option, a compressed air inlet to the passage channel can be provided.

The wiping element may include a basic body which extends over the diameter of the surface of the lens. Further, the wiping element may include at least one wiping lip which extends from said basic body in the direction of the lens surface, and a foot on the side opposite the wiping lip. Preferably, the foot is mounted movably in a frame. Such a wiping element is on the one hand sufficiently stable to withstand the stresses during wiping and also while a motor vehicle is being driven, but on the one hand sufficiently flexible and mobile.

The wiping element may also include a shape memory element where such an element can preferably be used as a drive for movement from one end position to another end position. See in this regard the embodiments described in European Patent Application No. EP 2 792 556 A1.

In an aspect, the rear view device for a motor vehicle has an optical device and a wiping device, where the lens is part of a camera unit, and a sensor element is provided which is suitable for the lens, typically in the focal plane of the lens or only slightly offset thereto. Here, the camera unit may be protected by a housing which in some areas is confined by the curved or calotte-shaped surface of the lens.

The frame may be attached to a housing of the camera unit and/or a housing of the rear view device. Thus, no separate attachment means for the frame outside of the rear view device must be provided.

The control or regulation unit of the rear view device may preferably be connected to a monitoring unit in the motor vehicle or provided by the unit, in order to trigger the movement of the wiping element and the fluid supply via the device. The latter is preferably performed by means of the recoil principle with springs and/or the use of motors.

