DE202008005314U1 - Distance sensor - Google Patents

Abstract

Optoelectronic distance sensor for detecting objects (2) in a surveillance area with a transmitting light beam emitting transmitter and a receiving light beam receiving receiver, an evaluation unit for determining distance values due to received signals and means for setting different switching points for different distances within a surveillance area, characterized in that the means being formed by at least two buttons (10 and 12), wherein a first button (10) for setting a first switching point for a first distance (D1) and a second button (12) for setting a second switching point for a second Distance (D2) is provided.

Description

The The invention relates to a distance sensor according to the preamble of Claim 1.

such Sensors are usually used to identify objects in particular Detect distances to the sensor. It should be noted whether an object is in a foreground area or a background area a monitoring area.

From the DE 197 54 963 A1 For example, a reflection light scanner is known for detecting objects in a surveillance area. The reflection light scanner has a transmitting light beam emitting transmitter and a receiving light beam receiving receiver. The receiver has a near element and a remote element. The transmitted light beams are aimed at setting a scanning distance on a test object. The ratio of the received signals generated at the near and far element is automatically adjusted by means of an adjustable resistance element to a value corresponding to the switching point of the reflection light scanner. The adjustment process can be activated via an externally operable signal line. In the case of the reflection light scanner, several detection ranges are provided, the adjustment of which takes place at test objects arranged at different distances in each case. To set different detection ranges separately adjustable resistance elements or alternatively a sensor bus interface are provided. Furthermore, a single key is provided to set the different detection ranges. Depending on whether the button is pressed short or long, the setting of the larger or smaller scanning distance is activated.

This However, sensor has significant disadvantages. For example, it can that happens to be a new one, via the sensor bus interface set setting of the switching points a setting of the switching points, which has been made with the adjustable resistor elements override would and the potentiometer setting the newly set Scopes contradicts. The disadvantage here is that between a scanning distance over Potentiometer and sensor bus interface must be distinguished. This requires additional effort in managing device settings through an evaluation unit. Next is a setting with the Button awkward, as a user between a short and a long press on the button and the corresponding operating times must comply with a to achieve a valid setting of the range. in this connection it may happen that already taught-in switching distances inadvertently changed if the key is pressed incorrectly become.

Of the Invention is based on the object, an improved distance sensor to provide, with the different scanning distances are easily adjusted can and the setting for a user very easy to understand and understand.

The Task is solved with an optoelectronic distance sensor to capture objects in a surveillance area, with a transmitting light beam emitting transmitter and a receiving light beam receiving receiver, an evaluation unit for determination of distance values due to the received signals and means for Setting of different switching points within a monitoring area, wherein the means is formed by at least two buttons. A first Button is for setting a first switching point for a first distance and a second button for the setting of a second switching point for a second Distance provided.

Thereby, that a separate key is provided for each switching point is, is setting two different switching points made with each of the switching points associated buttons and Each key is clearly and clearly assigned to exactly one switching point. For this purpose, the buttons preferably have different markings on, for example, different characters or different Colours. A user can by providing separate keys intuitively teach in two switching distances for a first switching distance of the first button is pressed and for a second switching distance of the second button is actuated. If the first switching distance to be corrected, so will only the first switching distance is taught again with the first key, without unintentionally changing the second switching distance.

in the Contrary to adjustable resistance elements are the invention Keys cost-effective and easier to use. Further a key does not have an unclear position, unlike a Potentiometer, if an adjustment of the switching points in addition is still feasible via an interface. There is thus no contradiction between the key setting and setting via an interface. An evaluation The key operation is also easier, since only one digital actuation signal is to evaluate, as opposed to a complex analog evaluation of a potentiometer.

Advantageously, the first key for the first switching point with a close distance is further away from an exit window for the light beams of the sensor than the second key for the second switching point with a greater distance to the sensor. Due to this geometric arrangement of the keys to each other in the direction of the distances to be detected is an accessory Ordering the keys for different switching distances particularly intuitive.

In Development of the invention, the keys are consecutively in the direction arranged the transmitted light beams. By this arrangement of the buttons It is particularly easy for an operator to recognize which Key to which switching point is assigned.

In Further development of the invention are the keys for learning a Switching point for a certain time, can be actuated for about 1 second, while the object to be detected is in a position at which the switching point should be located. The switching point So it is not learned until after the button for a period of time of 1 second has been pressed. This will be a mistake Teach-in due to a short unintentional actuation avoided the keys. Only when the button for a certain Time, for example in the range of 0.5 to 3 seconds, preferably 1 second is pressed, is the switching point learned.

In In another embodiment, each key is a single one assigned to a common display element. Through this display element An acknowledgment signal is issued when a switching point is effective was learned. This makes it easy for the user recognizable whether the teach-in process was successful. For example no object is placed in the detection area and it becomes a key pressed to teach a switching point, can by means of the optical display element an error message is output, for example, with a flashing signal to indicate that no object can be detected.

In Development of the invention, each key is at least one assigned to separate display element. This allows the display information directly the associated key and thus a specific associated Switching distance can be assigned. With the help of the display element can in addition to the successful teach-in of a switching point and a Actuation of the distance sensor will be displayed to the display faultless function of the sensor.

Of the Sensor is preferably designed either as a triangulation sensor, wherein the receiver is a spatially resolving receiver is or alternatively as a light transit time sensor, wherein the evaluation unit for Evaluation of a light transit time is suitable. However, the sensor can also on other measurement principles, such as stereoscopy based.

in the The invention is based on exemplary embodiments explained in detail with reference to the drawing.

In the drawing shows:

1 and 2 ; a schematic representation of a distance sensor according to the invention 1 ,

1 shows a distance sensor 1 , which works according to the triangulation principle, for example. The sensor 1 has a housing 8th , a connection cable 18 , an exit window 20 , a transmitter and a spatially resolving receiver. The receiver is connected to an evaluation unit. Beams of the transmitter exit through the exit window and strike an object 2 , Reflecting beams of light from the object strike the receiver.

A change a distance of a reflecting or remitting object leads to a shift of a corresponding light spot on the receiver of the sensor, for example a differential photodiode. This shift causes a corresponding change of received signals, which further processed by an evaluation and evaluated. Starting from the received signals at a corresponding distance D1, a switching point is set.

The transmitter of the optoelectronic distance sensor 1 is essentially in a focal plane one on the housing 8th of the sensor 1 arranged transmit lens arranged. The housing 8th The sensor also has a receiving lens adjacent to the transmitting lens. Inside the sensor 1 , in the region of the image plane of the receiving lens, there is the receiver whose photosensitive surface is arranged substantially parallel to the image plane of the receiving lens. The receiver is spatially resolved, ie its output signals provide information about which area of its photosensitive surface is acted upon by the received light beam. If the distance D1 of the object from the sensor 1 changed, the beam deflection along the photosensitive surface of the receiver changes. The output signals of the receiver are supplied to the evaluation unit via signal outputs. This is designed so that they have different output signals of the receiver at different distances of the object 2 from the sensor can assign.

A memory is connected to the evaluation unit for storing reference values for different switching points at different distances. For this purpose, two keys are according to the invention 10 and 12 accessible from outside on the sensor 1 appropriate.

The two buttons 10 and 12 are in a row behind each other in the direction of the outgoing light rays of the sensor 1 arranged. According to this embodiment, two switching points at two different distances D1 and D2 of an object 2 taught in, according to 1 and 2 , This is the object 2 first at a first smaller distance D1 from the distance sensor 1 positioned so that the object 2 from the transmission light 4 is charged. Starting from the received light 14 the distance D1 becomes the object 2 certainly. Around a first switching point of the sensor 1 learning and saving is now a first button by a user 10 pressed. In this case, the evaluation unit stores the currently detected distance value in the memory and assigns it to a first switching interval for generating a first switching signal as soon as this switching interval is undershot or exceeded. To teach in a second switching distance, the object according to 2 in a second desired, larger distance D2 from the sensor 1 positioned so that the object 2 in turn is detected by the transmitted light beams. By pressing a second button 12 Now, the currently detected, more distant distance value D2 is stored in the memory and associated with a second switching distance D2, to generate a second switching signal as soon as this switching distance is exceeded or exceeded.

If the first switching point is to be corrected, the object becomes 2 simply repositioned and using the first button 10 the first switching point taught again. The second switching point can not be mistakenly changed or deleted, but remains unchanged.

Alone through the geometric arrangement of the two buttons 10 and 12 is clear to the user and easy to recognize which of the buttons 10 and 12 which switching point is assigned. For further clarification on the keys 10 and 12 or appropriate symbols may be appropriate in the immediate vicinity. The button's 10 and 12 can also be shaped differently or have a different color.

Next is for both buttons 10 and 12 a common or alternatively a separate display element 16 provided for the visual representation of a valid taught switching point or for error and / or status display.

To withstand environmental influences, is the housing 8th , the button's 10 and 12 and optionally the display elements 16 designed in accordance with an IP65, IP67 or higher degree of protection, so that the sensor 1 Insensitive to dust and moisture.

The distance sensor 1 can also be designed as a light transit time sensor. Here, the receiver and the evaluation unit is designed to evaluate a light transit time of the transmitted light and to specify a corresponding distance value to an object. The sensor may also be based on other comparable measurement principles for distance measurement, such as stereoscopy.

1

optoelectronic Distance sensor

2

object

4

transmitted light

8th

casing

10

first button

12

second button

14

received Light, reception light

16

indicators

18

connection cable

20

exit window

D1

Distance, distance

D2

Distance, distance

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• DE 19754963 A1 [0003]

Claims (8)

Opto-electronic distance sensor for detecting objects ( 2 ) in a monitoring area with a transmitting light-emitting transmitter and a receiving light beam receiving receiver, an evaluation unit for determining distance values due to received signals and means for setting different switching points for different distances within a monitoring range, characterized in that the means by at least two buttons ( 10 and 12 ), wherein a first button ( 10 ) for setting a first switching point for a first distance (D1) and a second button ( 12 ) is provided for setting a second switching point for a second distance (D2). Optoelectronic distance sensor according to claim 1, characterized in that the first button ( 10 ) further from an exit window for the light beams of the sensor ( 1 ) is removed as the second button ( 12 ), and the first distance (D1) is smaller than the second distance (D2). Optoelectronic distance sensor according to claim 2, characterized in that the keys ( 10 . 12 ) are arranged one behind the other in a row in the direction of the transmitted light beams. Optoelectronic distance sensor according to one of the preceding claims, characterized in that the keys ( 10 . 12 ) are taught for teaching the switching points for a certain time, about 1 second, during which the object to be detected ( 2 ) at the position where the switching point is to be located. Optoelectronic distance sensor according to one of the preceding claims, characterized in that the keys ( 10 . 12 ) is associated with a single common display element. Optoelectronic distance sensor according to one of the preceding claims 1 to 4, characterized in that each key ( 10 . 12 ) at least one separate display element ( 16 ) assigned. Optoelectronic distance sensor according to one of the preceding claims, characterized in that the sensor ( 1 ) is designed as a triangulation sensor and the receiver is a spatially resolving receiver. Optoelectronic distance sensor according to one of the preceding claims, characterized in that the sensor ( 1 ) is designed as a light transit time sensor and the evaluation unit is designed to evaluate a light transit time.